[PATCH v3 0/9] crypto/nx: Enable GZIP engine and provide userpace API

[PATCH v3 0/9] crypto/nx: Enable GZIP engine and provide userpace API

[Haren Myneni]

Power9 processor supports Virtual Accelerator Switchboard (VAS) which
allows kernel and userspace to send compression requests to Nest
Accelerator (NX) directly. The NX unit comprises of 2 842 compression
engines and 1 GZIP engine. Linux kernel already has 842 compression
support on kernel. This patch series adds GZIP compression support
from user space. The GZIP Compression engine implements the ZLIB and
GZIP compression algorithms. No plans of adding NX-GZIP compression
support in kernel right now.

Applications can send requests to NX directly with COPY/PASTE
instructions. But kernel has to establish channel / window on NX-GZIP
device for the userspace. So userspace access to the GZIP engine is
provided through /dev/crypto/nx-gzip device with several operations.

An application must open the this device to obtain a file descriptor (fd).
Using the fd, application should issue the VAS_TX_WIN_OPEN ioctl to
establish a connection to the engine. Once window is opened, should use
mmap() system call to map the hardware address of engine's request queue
into the application's virtual address space. Then user space forms the
request as co-processor Request Block (CRB) and paste this CRB on the
mapped HW address using COPY/PASTE instructions. Application can poll
on status flags (part of CRB) with timeout for request completion.

For VAS_TX_WIN_OPEN ioctl, if user space passes vas_id = -1 (struct
vas_tx_win_open_attr), kernel determines the VAS instance on the
corresponding chip based on the CPU on which the process is executing.
Otherwise, the specified VAS instance is used if application passes the
proper VAS instance (vas_id listed in /proc/device-tree/vas@*/ibm,vas_id).

Process can open multiple windows with different FDs or can send several
requests to NX on the same window at the same time.

A userspace library libnxz is available:
        https://github.com/abalib/power-gzip

Applications that use inflate/deflate calls can link with libNXz and use
NX GZIP compression without any modification.

Tested the available 842 compression on power8 and power9 system to make
sure no regression and tested GZIP compression on power9 with tests
available in the above link.

Thanks to Bulent Abali for nxz library and tests development.

Changelog:
V2:
  - Move user space API code to powerpc as suggested. Also this API
    can be extended to any other coprocessor type that VAS can support
    in future. Example: Fast thread wakeup feature from VAS
  - Rebased to 5.6-rc3

V3:
  - Fix sparse warnings (patches 3&6)

Haren Myneni (9):
  powerpc/vas: Initialize window attributes for GZIP coprocessor type
  powerpc/vas: Define VAS_TX_WIN_OPEN ioctl API
  powerpc/vas: Add VAS user space API
  crypto/nx: Initialize coproc entry with kzalloc
  crypto/nx: Rename nx-842-powernv file name to nx-common-powernv
  crypto/NX: Make enable code generic to add new GZIP compression type
  crypto/nx: Enable and setup GZIP compresstion type
  crypto/nx: Remove 'pid' in vas_tx_win_attr struct
  Documentation/powerpc: VAS API

 Documentation/powerpc/index.rst                    |    1 +
 Documentation/powerpc/vas-api.rst                  |  246 +++++
 Documentation/userspace-api/ioctl/ioctl-number.rst |    1 +
 arch/powerpc/include/asm/vas.h                     |   12 +-
 arch/powerpc/include/uapi/asm/vas-api.h            |   22 +
 arch/powerpc/platforms/powernv/Makefile            |    2 +-
 arch/powerpc/platforms/powernv/vas-api.c           |  290 +++++
 arch/powerpc/platforms/powernv/vas-window.c        |   23 +-
 arch/powerpc/platforms/powernv/vas.h               |    2 +
 drivers/crypto/nx/Makefile                         |    2 +-
 drivers/crypto/nx/nx-842-powernv.c                 | 1062 ------------------
 drivers/crypto/nx/nx-common-powernv.c              | 1133 ++++++++++++++++++++
 12 files changed, 1723 insertions(+), 1073 deletions(-)
 create mode 100644 Documentation/powerpc/vas-api.rst
 create mode 100644 arch/powerpc/include/uapi/asm/vas-api.h
 create mode 100644 arch/powerpc/platforms/powernv/vas-api.c
 delete mode 100644 drivers/crypto/nx/nx-842-powernv.c
 create mode 100644 drivers/crypto/nx/nx-common-powernv.c

-- 
1.8.3.1

[PATCH v3 1/9] powerpc/vas: Initialize window attributes for GZIP coprocessor type

[Haren Myneni]

Initialize send and receive window attributes for GZIP high and
normal priority types.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 arch/powerpc/platforms/powernv/vas-window.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index c60accd..e9ab851 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -817,7 +817,8 @@ void vas_init_rx_win_attr(struct vas_rx_win_attr *rxattr, enum vas_cop_type cop)
 {
 	memset(rxattr, 0, sizeof(*rxattr));
 
-	if (cop == VAS_COP_TYPE_842 || cop == VAS_COP_TYPE_842_HIPRI) {
+	if (cop == VAS_COP_TYPE_842 || cop == VAS_COP_TYPE_842_HIPRI ||
+		cop == VAS_COP_TYPE_GZIP || cop == VAS_COP_TYPE_GZIP_HIPRI) {
 		rxattr->pin_win = true;
 		rxattr->nx_win = true;
 		rxattr->fault_win = false;
@@ -892,7 +893,8 @@ void vas_init_tx_win_attr(struct vas_tx_win_attr *txattr, enum vas_cop_type cop)
 {
 	memset(txattr, 0, sizeof(*txattr));
 
-	if (cop == VAS_COP_TYPE_842 || cop == VAS_COP_TYPE_842_HIPRI) {
+	if (cop == VAS_COP_TYPE_842 || cop == VAS_COP_TYPE_842_HIPRI ||
+		cop == VAS_COP_TYPE_GZIP || cop == VAS_COP_TYPE_GZIP_HIPRI) {
 		txattr->rej_no_credit = false;
 		txattr->rx_wcred_mode = true;
 		txattr->tx_wcred_mode = true;
@@ -976,9 +978,14 @@ static bool tx_win_args_valid(enum vas_cop_type cop,
 	if (attr->wcreds_max > VAS_TX_WCREDS_MAX)
 		return false;
 
-	if (attr->user_win &&
-			(cop != VAS_COP_TYPE_FTW || attr->rsvd_txbuf_count))
-		return false;
+	if (attr->user_win) {
+		if (attr->rsvd_txbuf_count)
+			return false;
+
+		if (cop != VAS_COP_TYPE_FTW && cop != VAS_COP_TYPE_GZIP &&
+			cop != VAS_COP_TYPE_GZIP_HIPRI)
+			return false;
+	}
 
 	return true;
 }
-- 
1.8.3.1

[PATCH v3 2/9] powerpc/vas: Define VAS_TX_WIN_OPEN ioctl API

[Haren Myneni]

Define the VAS_TX_WIN_OPEN ioctl interface for NX GZIP access
from user space. This interface is used to open GZIP send window and
mmap region which can be used by userspace to send requests to NX
directly with copy/paste instructions.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 Documentation/userspace-api/ioctl/ioctl-number.rst |  1 +
 arch/powerpc/include/uapi/asm/vas-api.h            | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 arch/powerpc/include/uapi/asm/vas-api.h

diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index 2e91370..deabc73 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -287,6 +287,7 @@ Code  Seq#    Include File                                           Comments
 'v'   00-1F  linux/fs.h                                              conflict!
 'v'   00-0F  linux/sonypi.h                                          conflict!
 'v'   00-0F  media/v4l2-subdev.h                                     conflict!
+'v'   20-27  arch/powerpc/include/uapi/asm/vas-api.h		     VAS API
 'v'   C0-FF  linux/meye.h                                            conflict!
 'w'   all                                                            CERN SCI driver
 'y'   00-1F                                                          packet based user level communications
diff --git a/arch/powerpc/include/uapi/asm/vas-api.h b/arch/powerpc/include/uapi/asm/vas-api.h
new file mode 100644
index 0000000..fe95d67
--- /dev/null
+++ b/arch/powerpc/include/uapi/asm/vas-api.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Copyright 2019 IBM Corp.
+ */
+
+#ifndef _UAPI_MISC_VAS_H
+#define _UAPI_MISC_VAS_H
+
+#include <asm/ioctl.h>
+
+#define VAS_MAGIC	'v'
+#define VAS_TX_WIN_OPEN	_IOW(VAS_MAGIC, 0x20, struct vas_tx_win_open_attr)
+
+struct vas_tx_win_open_attr {
+	__u32	version;
+	__s16	vas_id;	/* specific instance of vas or -1 for default */
+	__u16	reserved1;
+	__u64	flags;	/* Future use */
+	__u64	reserved2[6];
+};
+
+#endif /* _UAPI_MISC_VAS_H */
-- 
1.8.3.1

[PATCH v3 3/9] powerpc/vas: Add VAS user space API

[Haren Myneni]

On power9, userspace can send GZIP compression requests directly to NX
once kernel establishes NX channel / window with VAS. This patch provides
user space API which allows user space to establish channel using open
VAS_TX_WIN_OPEN ioctl, mmap and close operations.

Each window corresponds to file descriptor and application can open
multiple windows. After the window is opened, VAS_TX_WIN_OPEN icoctl to
open a window on specific VAS instance, mmap() system call to map
the hardware address of engine's request queue into the application's
virtual address space.

Then the application can then submit one or more requests to the the
engine by using the copy/paste instructions and pasting the CRBs to
the virtual address (aka paste_address) returned by mmap().

Only NX GZIP coprocessor type is supported right now and allow GZIP
engine access via /dev/crypto/nx-gzip device node.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 arch/powerpc/include/asm/vas.h              |  11 ++
 arch/powerpc/platforms/powernv/Makefile     |   2 +-
 arch/powerpc/platforms/powernv/vas-api.c    | 290 ++++++++++++++++++++++++++++
 arch/powerpc/platforms/powernv/vas-window.c |   6 +-
 arch/powerpc/platforms/powernv/vas.h        |   2 +
 5 files changed, 307 insertions(+), 4 deletions(-)
 create mode 100644 arch/powerpc/platforms/powernv/vas-api.c

diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index f93e6b0..e064953 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h
@@ -163,4 +163,15 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
  */
 int vas_paste_crb(struct vas_window *win, int offset, bool re);
 
+/*
+ * Register / unregister coprocessor type to VAS API which will be exported
+ * to user space. Applications can use this API to open / close window
+ * which can be used to send / receive requests directly to cooprcessor.
+ *
+ * Only NX GZIP coprocessor type is supported now, but this API can be
+ * used for others in future.
+ */
+int vas_register_coproc_api(struct module *mod);
+void vas_unregister_coproc_api(void);
+
 #endif /* __ASM_POWERPC_VAS_H */
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index 395789f..fe3f0fb 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -17,7 +17,7 @@ obj-$(CONFIG_MEMORY_FAILURE)	+= opal-memory-errors.o
 obj-$(CONFIG_OPAL_PRD)	+= opal-prd.o
 obj-$(CONFIG_PERF_EVENTS) += opal-imc.o
 obj-$(CONFIG_PPC_MEMTRACE)	+= memtrace.o
-obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o
+obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o vas-api.o
 obj-$(CONFIG_OCXL_BASE)	+= ocxl.o
 obj-$(CONFIG_SCOM_DEBUGFS) += opal-xscom.o
 obj-$(CONFIG_PPC_SECURE_BOOT) += opal-secvar.o
diff --git a/arch/powerpc/platforms/powernv/vas-api.c b/arch/powerpc/platforms/powernv/vas-api.c
new file mode 100644
index 0000000..3473a4a
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/vas-api.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * VAS user space API for its accelerators (Only NX-GZIP is supported now)
+ * Copyright (C) 2019 Haren Myneni, IBM Corp
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <asm/vas.h>
+#include <uapi/asm/vas-api.h>
+#include "vas.h"
+
+/*
+ * The driver creates the device node that can be used as follows:
+ * For NX-GZIP
+ *
+ *	fd = open("/dev/crypto/nx-gzip", O_RDWR);
+ *	rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr);
+ *	paste_addr = mmap(NULL, PAGE_SIZE, prot, MAP_SHARED, fd, 0ULL).
+ *	vas_copy(&crb, 0, 1);
+ *	vas_paste(paste_addr, 0, 1);
+ *	close(fd) or exit process to close window.
+ *
+ * where "vas_copy" and "vas_paste" are defined in copy-paste.h.
+ * copy/paste returns to the user space directly. So refer NX hardware
+ * documententation for excat copy/paste usage and completion / error
+ * conditions.
+ */
+
+static char	*coproc_dev_name = "nx-gzip";
+static atomic_t	coproc_instid = ATOMIC_INIT(0);
+
+/*
+ * Wrapper object for the nx-gzip device - there is just one instance of
+ * this node for the whole system.
+ */
+static struct coproc_dev {
+	struct cdev cdev;
+	struct device *device;
+	char *name;
+	dev_t devt;
+	struct class *class;
+} coproc_device;
+
+/*
+ * One instance per open of a nx-gzip device. Each coproc_instance is
+ * associated with a VAS window after the caller issues
+ * VAS_GZIP_TX_WIN_OPEN ioctl.
+ */
+struct coproc_instance {
+	int id;
+	struct vas_window *txwin;
+};
+
+static char *coproc_devnode(struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev));
+}
+
+static int coproc_open(struct inode *inode, struct file *fp)
+{
+	struct coproc_instance *instance;
+
+	instance = kzalloc(sizeof(*instance), GFP_KERNEL);
+	if (!instance)
+		return -ENOMEM;
+
+	instance->id = atomic_inc_return(&coproc_instid);
+
+	fp->private_data = instance;
+	return 0;
+}
+
+static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
+{
+	int rc, vasid;
+	struct vas_tx_win_attr txattr;
+	struct vas_tx_win_open_attr uattr;
+	void __user *uptr = (void __user *)arg;
+	struct vas_window *txwin;
+	struct coproc_instance *nxti = fp->private_data;
+
+	if (!nxti)
+		return -EINVAL;
+
+	/*
+	 * One window for file descriptor
+	 */
+	if (nxti->txwin)
+		return -EEXIST;
+
+	rc = copy_from_user(&uattr, uptr, sizeof(uattr));
+	if (rc) {
+		pr_err("%s(): copy_from_user() returns %d\n", __func__, rc);
+		return -EFAULT;
+	}
+
+	if (uattr.version != 1) {
+		pr_err("Invalid version\n");
+		return -EINVAL;
+	}
+
+	vasid = uattr.vas_id;
+
+	memset(&txattr, 0, sizeof(struct vas_tx_win_attr));
+	vas_init_tx_win_attr(&txattr, VAS_COP_TYPE_GZIP);
+
+	txattr.lpid = mfspr(SPRN_LPID);
+	txattr.pidr = mfspr(SPRN_PID);
+	txattr.user_win = true;
+	txattr.rsvd_txbuf_count = false;
+	txattr.pswid = false;
+	/*
+	 * txattr.wcreds_max is set to VAS_WCREDS_DEFAULT (1024) in
+	 * vas-window.c, but can be changed specific to GZIP depends
+	 * on user space need.
+	 * If needed to set txattr.wcreds_max here.
+	 */
+
+	pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
+				mfspr(SPRN_PID));
+
+	txwin = vas_tx_win_open(vasid, VAS_COP_TYPE_GZIP, &txattr);
+	if (IS_ERR(txwin)) {
+		pr_err("%s() vas_tx_win_open() failed, %ld\n", __func__,
+					PTR_ERR(txwin));
+		return PTR_ERR(txwin);
+	}
+
+	nxti->txwin = txwin;
+
+	return 0;
+}
+
+static int coproc_release(struct inode *inode, struct file *fp)
+{
+	struct coproc_instance *instance;
+
+	instance = fp->private_data;
+
+	if (instance && instance->txwin) {
+		vas_win_close(instance->txwin);
+		instance->txwin = NULL;
+	}
+
+	/*
+	 * We don't know here if user has other receive windows
+	 * open, so we can't really call clear_thread_tidr().
+	 * So, once the process calls set_thread_tidr(), the
+	 * TIDR value sticks around until process exits, resulting
+	 * in an extra copy in restore_sprs().
+	 */
+
+	kfree(instance);
+	fp->private_data = NULL;
+	atomic_dec(&coproc_instid);
+
+	return 0;
+}
+
+static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
+{
+	int rc;
+	pgprot_t prot;
+	u64 paste_addr;
+	unsigned long pfn;
+	struct coproc_instance *instance = fp->private_data;
+
+	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
+		pr_debug("%s(): size 0x%zx, PAGE_SIZE 0x%zx\n", __func__,
+				(vma->vm_end - vma->vm_start), PAGE_SIZE);
+		return -EINVAL;
+	}
+
+	/* Ensure instance has an open send window */
+	if (!instance->txwin) {
+		pr_err("%s(): No send window open?\n", __func__);
+		return -EINVAL;
+	}
+
+	vas_win_paste_addr(instance->txwin, &paste_addr, NULL);
+	pfn = paste_addr >> PAGE_SHIFT;
+
+	/* flags, page_prot from cxl_mmap(), except we want cachable */
+	vma->vm_flags |= VM_IO | VM_PFNMAP;
+	vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
+
+	prot = __pgprot(pgprot_val(vma->vm_page_prot) | _PAGE_DIRTY);
+
+	rc = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
+			vma->vm_end - vma->vm_start, prot);
+
+	pr_devel("%s(): paste addr %llx at %lx, rc %d\n", __func__,
+			paste_addr, vma->vm_start, rc);
+
+	return rc;
+}
+
+static long coproc_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case VAS_TX_WIN_OPEN:
+		return coproc_ioc_tx_win_open(fp, arg);
+	default:
+		return -EINVAL;
+	}
+}
+
+static struct file_operations coproc_fops = {
+	.open = coproc_open,
+	.release = coproc_release,
+	.mmap = coproc_mmap,
+	.unlocked_ioctl = coproc_ioctl,
+};
+
+/*
+ * Supporting only nx-gzip coprocessor type now, but this API code
+ * extended to other coprocessor types later.
+ */
+int vas_register_coproc_api(struct module *mod)
+{
+	int rc = -EINVAL;
+	dev_t devno;
+
+	rc = alloc_chrdev_region(&coproc_device.devt, 1, 1, "nx-gzip");
+	if (rc) {
+		pr_err("Unable to allocate coproc major number: %i\n", rc);
+		return rc;
+	}
+
+	pr_devel("NX-GZIP device allocated, dev [%i,%i]\n",
+			MAJOR(coproc_device.devt), MINOR(coproc_device.devt));
+
+	coproc_device.class = class_create(mod, "nx-gzip");
+	if (IS_ERR(coproc_device.class)) {
+		rc = PTR_ERR(coproc_device.class);
+		pr_err("Unable to create NX-GZIP class %d\n", rc);
+		goto err_class;
+	}
+	coproc_device.class->devnode = coproc_devnode;
+
+	coproc_fops.owner = mod;
+	cdev_init(&coproc_device.cdev, &coproc_fops);
+
+	devno = MKDEV(MAJOR(coproc_device.devt), 0);
+	rc = cdev_add(&coproc_device.cdev, devno, 1);
+	if (rc) {
+		pr_err("cdev_add() failed %d\n", rc);
+		goto err_cdev;
+	}
+
+	coproc_device.device = device_create(coproc_device.class, NULL,
+			devno, NULL, coproc_dev_name, MINOR(devno));
+	if (IS_ERR(coproc_device.device)) {
+		rc = PTR_ERR(coproc_device.device);
+		pr_err("Unable to create coproc-%d %d\n", MINOR(devno), rc);
+		goto err;
+	}
+
+	pr_devel("%s: Added dev [%d,%d]\n", __func__, MAJOR(devno),
+			MINOR(devno));
+
+	return 0;
+
+err:
+	cdev_del(&coproc_device.cdev);
+err_cdev:
+	class_destroy(coproc_device.class);
+err_class:
+	unregister_chrdev_region(coproc_device.devt, 1);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(vas_register_coproc_api);
+
+void vas_unregister_coproc_api(void)
+{
+	dev_t devno;
+
+	cdev_del(&coproc_device.cdev);
+	devno = MKDEV(MAJOR(coproc_device.devt), 0);
+	device_destroy(coproc_device.class, devno);
+
+	class_destroy(coproc_device.class);
+	unregister_chrdev_region(coproc_device.devt, 1);
+}
+EXPORT_SYMBOL_GPL(vas_unregister_coproc_api);
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index e9ab851..7484296 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -26,7 +26,7 @@
  * Compute the paste address region for the window @window using the
  * ->paste_base_addr and ->paste_win_id_shift we got from device tree.
  */
-static void compute_paste_address(struct vas_window *window, u64 *addr, int *len)
+void vas_win_paste_addr(struct vas_window *window, u64 *addr, int *len)
 {
 	int winid;
 	u64 base, shift;
@@ -80,7 +80,7 @@ static void *map_paste_region(struct vas_window *txwin)
 		goto free_name;
 
 	txwin->paste_addr_name = name;
-	compute_paste_address(txwin, &start, &len);
+	vas_win_paste_addr(txwin, &start, &len);
 
 	if (!request_mem_region(start, len, name)) {
 		pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
@@ -138,7 +138,7 @@ static void unmap_paste_region(struct vas_window *window)
 	u64 busaddr_start;
 
 	if (window->paste_kaddr) {
-		compute_paste_address(window, &busaddr_start, &len);
+		vas_win_paste_addr(window, &busaddr_start, &len);
 		unmap_region(window->paste_kaddr, busaddr_start, len);
 		window->paste_kaddr = NULL;
 		kfree(window->paste_addr_name);
diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
index 8c39a7d..a10abed 100644
--- a/arch/powerpc/platforms/powernv/vas.h
+++ b/arch/powerpc/platforms/powernv/vas.h
@@ -431,6 +431,8 @@ struct vas_winctx {
 extern void vas_return_credit(struct vas_window *window, bool tx);
 extern struct vas_window *vas_pswid_to_window(struct vas_instance *vinst,
 						uint32_t pswid);
+extern void vas_win_paste_addr(struct vas_window *window, u64 *addr,
+					int *len);
 
 static inline int vas_window_pid(struct vas_window *window)
 {
-- 
1.8.3.1

[PATCH v3 4/9] crypto/nx: Initialize coproc entry with kzalloc

[Haren Myneni]

coproc entry is initialized during NX probe on power9, but not on P8.
nx842_delete_coprocs() is used for both and frees receive window if it
is allocated. Getting crash for rmmod on P8 since coproc->vas.rxwin
is not initialized.

This patch replaces kmalloc with kzalloc in nx842_powernv_probe()

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 drivers/crypto/nx/nx-842-powernv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c
index c037a24..8e63326 100644
--- a/drivers/crypto/nx/nx-842-powernv.c
+++ b/drivers/crypto/nx/nx-842-powernv.c
@@ -922,7 +922,7 @@ static int __init nx842_powernv_probe(struct device_node *dn)
 		return -EINVAL;
 	}
 
-	coproc = kmalloc(sizeof(*coproc), GFP_KERNEL);
+	coproc = kzalloc(sizeof(*coproc), GFP_KERNEL);
 	if (!coproc)
 		return -ENOMEM;
 
-- 
1.8.3.1

[PATCH v3 5/9] crypto/nx: Rename nx-842-powernv file name to nx-common-powernv

[Haren Myneni]

Rename nx-842-powernv.c to nx-common-powernv.c to add code for setup
and enable new GZIP compression type. The actual functionality is not
changed in this patch.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 drivers/crypto/nx/Makefile            |    2 +-
 drivers/crypto/nx/nx-842-powernv.c    | 1062 ---------------------------------
 drivers/crypto/nx/nx-common-powernv.c | 1062 +++++++++++++++++++++++++++++++++
 3 files changed, 1063 insertions(+), 1063 deletions(-)
 delete mode 100644 drivers/crypto/nx/nx-842-powernv.c
 create mode 100644 drivers/crypto/nx/nx-common-powernv.c

diff --git a/drivers/crypto/nx/Makefile b/drivers/crypto/nx/Makefile
index 015155d..bc89a20 100644
--- a/drivers/crypto/nx/Makefile
+++ b/drivers/crypto/nx/Makefile
@@ -15,4 +15,4 @@ obj-$(CONFIG_CRYPTO_DEV_NX_COMPRESS_PSERIES) += nx-compress-pseries.o nx-compres
 obj-$(CONFIG_CRYPTO_DEV_NX_COMPRESS_POWERNV) += nx-compress-powernv.o nx-compress.o
 nx-compress-objs := nx-842.o
 nx-compress-pseries-objs := nx-842-pseries.o
-nx-compress-powernv-objs := nx-842-powernv.o
+nx-compress-powernv-objs := nx-common-powernv.o
diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c
deleted file mode 100644
index 8e63326..0000000
--- a/drivers/crypto/nx/nx-842-powernv.c
+++ /dev/null
@@ -1,1062 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * Driver for IBM PowerNV 842 compression accelerator
- *
- * Copyright (C) 2015 Dan Streetman, IBM Corp
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include "nx-842.h"
-
-#include <linux/timer.h>
-
-#include <asm/prom.h>
-#include <asm/icswx.h>
-#include <asm/vas.h>
-#include <asm/reg.h>
-#include <asm/opal-api.h>
-#include <asm/opal.h>
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
-MODULE_DESCRIPTION("842 H/W Compression driver for IBM PowerNV processors");
-MODULE_ALIAS_CRYPTO("842");
-MODULE_ALIAS_CRYPTO("842-nx");
-
-#define WORKMEM_ALIGN	(CRB_ALIGN)
-#define CSB_WAIT_MAX	(5000) /* ms */
-#define VAS_RETRIES	(10)
-
-struct nx842_workmem {
-	/* Below fields must be properly aligned */
-	struct coprocessor_request_block crb; /* CRB_ALIGN align */
-	struct data_descriptor_entry ddl_in[DDL_LEN_MAX]; /* DDE_ALIGN align */
-	struct data_descriptor_entry ddl_out[DDL_LEN_MAX]; /* DDE_ALIGN align */
-	/* Above fields must be properly aligned */
-
-	ktime_t start;
-
-	char padding[WORKMEM_ALIGN]; /* unused, to allow alignment */
-} __packed __aligned(WORKMEM_ALIGN);
-
-struct nx842_coproc {
-	unsigned int chip_id;
-	unsigned int ct;
-	unsigned int ci;	/* Coprocessor instance, used with icswx */
-	struct {
-		struct vas_window *rxwin;
-		int id;
-	} vas;
-	struct list_head list;
-};
-
-/*
- * Send the request to NX engine on the chip for the corresponding CPU
- * where the process is executing. Use with VAS function.
- */
-static DEFINE_PER_CPU(struct vas_window *, cpu_txwin);
-
-/* no cpu hotplug on powernv, so this list never changes after init */
-static LIST_HEAD(nx842_coprocs);
-static unsigned int nx842_ct;	/* used in icswx function */
-
-static int (*nx842_powernv_exec)(const unsigned char *in,
-				unsigned int inlen, unsigned char *out,
-				unsigned int *outlenp, void *workmem, int fc);
-
-/**
- * setup_indirect_dde - Setup an indirect DDE
- *
- * The DDE is setup with the the DDE count, byte count, and address of
- * first direct DDE in the list.
- */
-static void setup_indirect_dde(struct data_descriptor_entry *dde,
-			       struct data_descriptor_entry *ddl,
-			       unsigned int dde_count, unsigned int byte_count)
-{
-	dde->flags = 0;
-	dde->count = dde_count;
-	dde->index = 0;
-	dde->length = cpu_to_be32(byte_count);
-	dde->address = cpu_to_be64(nx842_get_pa(ddl));
-}
-
-/**
- * setup_direct_dde - Setup single DDE from buffer
- *
- * The DDE is setup with the buffer and length.  The buffer must be properly
- * aligned.  The used length is returned.
- * Returns:
- *   N    Successfully set up DDE with N bytes
- */
-static unsigned int setup_direct_dde(struct data_descriptor_entry *dde,
-				     unsigned long pa, unsigned int len)
-{
-	unsigned int l = min_t(unsigned int, len, LEN_ON_PAGE(pa));
-
-	dde->flags = 0;
-	dde->count = 0;
-	dde->index = 0;
-	dde->length = cpu_to_be32(l);
-	dde->address = cpu_to_be64(pa);
-
-	return l;
-}
-
-/**
- * setup_ddl - Setup DDL from buffer
- *
- * Returns:
- *   0		Successfully set up DDL
- */
-static int setup_ddl(struct data_descriptor_entry *dde,
-		     struct data_descriptor_entry *ddl,
-		     unsigned char *buf, unsigned int len,
-		     bool in)
-{
-	unsigned long pa = nx842_get_pa(buf);
-	int i, ret, total_len = len;
-
-	if (!IS_ALIGNED(pa, DDE_BUFFER_ALIGN)) {
-		pr_debug("%s buffer pa 0x%lx not 0x%x-byte aligned\n",
-			 in ? "input" : "output", pa, DDE_BUFFER_ALIGN);
-		return -EINVAL;
-	}
-
-	/* only need to check last mult; since buffer must be
-	 * DDE_BUFFER_ALIGN aligned, and that is a multiple of
-	 * DDE_BUFFER_SIZE_MULT, and pre-last page DDE buffers
-	 * are guaranteed a multiple of DDE_BUFFER_SIZE_MULT.
-	 */
-	if (len % DDE_BUFFER_LAST_MULT) {
-		pr_debug("%s buffer len 0x%x not a multiple of 0x%x\n",
-			 in ? "input" : "output", len, DDE_BUFFER_LAST_MULT);
-		if (in)
-			return -EINVAL;
-		len = round_down(len, DDE_BUFFER_LAST_MULT);
-	}
-
-	/* use a single direct DDE */
-	if (len <= LEN_ON_PAGE(pa)) {
-		ret = setup_direct_dde(dde, pa, len);
-		WARN_ON(ret < len);
-		return 0;
-	}
-
-	/* use the DDL */
-	for (i = 0; i < DDL_LEN_MAX && len > 0; i++) {
-		ret = setup_direct_dde(&ddl[i], pa, len);
-		buf += ret;
-		len -= ret;
-		pa = nx842_get_pa(buf);
-	}
-
-	if (len > 0) {
-		pr_debug("0x%x total %s bytes 0x%x too many for DDL.\n",
-			 total_len, in ? "input" : "output", len);
-		if (in)
-			return -EMSGSIZE;
-		total_len -= len;
-	}
-	setup_indirect_dde(dde, ddl, i, total_len);
-
-	return 0;
-}
-
-#define CSB_ERR(csb, msg, ...)					\
-	pr_err("ERROR: " msg " : %02x %02x %02x %02x %08x\n",	\
-	       ##__VA_ARGS__, (csb)->flags,			\
-	       (csb)->cs, (csb)->cc, (csb)->ce,			\
-	       be32_to_cpu((csb)->count))
-
-#define CSB_ERR_ADDR(csb, msg, ...)				\
-	CSB_ERR(csb, msg " at %lx", ##__VA_ARGS__,		\
-		(unsigned long)be64_to_cpu((csb)->address))
-
-/**
- * wait_for_csb
- */
-static int wait_for_csb(struct nx842_workmem *wmem,
-			struct coprocessor_status_block *csb)
-{
-	ktime_t start = wmem->start, now = ktime_get();
-	ktime_t timeout = ktime_add_ms(start, CSB_WAIT_MAX);
-
-	while (!(READ_ONCE(csb->flags) & CSB_V)) {
-		cpu_relax();
-		now = ktime_get();
-		if (ktime_after(now, timeout))
-			break;
-	}
-
-	/* hw has updated csb and output buffer */
-	barrier();
-
-	/* check CSB flags */
-	if (!(csb->flags & CSB_V)) {
-		CSB_ERR(csb, "CSB still not valid after %ld us, giving up",
-			(long)ktime_us_delta(now, start));
-		return -ETIMEDOUT;
-	}
-	if (csb->flags & CSB_F) {
-		CSB_ERR(csb, "Invalid CSB format");
-		return -EPROTO;
-	}
-	if (csb->flags & CSB_CH) {
-		CSB_ERR(csb, "Invalid CSB chaining state");
-		return -EPROTO;
-	}
-
-	/* verify CSB completion sequence is 0 */
-	if (csb->cs) {
-		CSB_ERR(csb, "Invalid CSB completion sequence");
-		return -EPROTO;
-	}
-
-	/* check CSB Completion Code */
-	switch (csb->cc) {
-	/* no error */
-	case CSB_CC_SUCCESS:
-		break;
-	case CSB_CC_TPBC_GT_SPBC:
-		/* not an error, but the compressed data is
-		 * larger than the uncompressed data :(
-		 */
-		break;
-
-	/* input data errors */
-	case CSB_CC_OPERAND_OVERLAP:
-		/* input and output buffers overlap */
-		CSB_ERR(csb, "Operand Overlap error");
-		return -EINVAL;
-	case CSB_CC_INVALID_OPERAND:
-		CSB_ERR(csb, "Invalid operand");
-		return -EINVAL;
-	case CSB_CC_NOSPC:
-		/* output buffer too small */
-		return -ENOSPC;
-	case CSB_CC_ABORT:
-		CSB_ERR(csb, "Function aborted");
-		return -EINTR;
-	case CSB_CC_CRC_MISMATCH:
-		CSB_ERR(csb, "CRC mismatch");
-		return -EINVAL;
-	case CSB_CC_TEMPL_INVALID:
-		CSB_ERR(csb, "Compressed data template invalid");
-		return -EINVAL;
-	case CSB_CC_TEMPL_OVERFLOW:
-		CSB_ERR(csb, "Compressed data template shows data past end");
-		return -EINVAL;
-	case CSB_CC_EXCEED_BYTE_COUNT:	/* P9 or later */
-		/*
-		 * DDE byte count exceeds the limit specified in Maximum
-		 * byte count register.
-		 */
-		CSB_ERR(csb, "DDE byte count exceeds the limit");
-		return -EINVAL;
-
-	/* these should not happen */
-	case CSB_CC_INVALID_ALIGN:
-		/* setup_ddl should have detected this */
-		CSB_ERR_ADDR(csb, "Invalid alignment");
-		return -EINVAL;
-	case CSB_CC_DATA_LENGTH:
-		/* setup_ddl should have detected this */
-		CSB_ERR(csb, "Invalid data length");
-		return -EINVAL;
-	case CSB_CC_WR_TRANSLATION:
-	case CSB_CC_TRANSLATION:
-	case CSB_CC_TRANSLATION_DUP1:
-	case CSB_CC_TRANSLATION_DUP2:
-	case CSB_CC_TRANSLATION_DUP3:
-	case CSB_CC_TRANSLATION_DUP4:
-	case CSB_CC_TRANSLATION_DUP5:
-	case CSB_CC_TRANSLATION_DUP6:
-		/* should not happen, we use physical addrs */
-		CSB_ERR_ADDR(csb, "Translation error");
-		return -EPROTO;
-	case CSB_CC_WR_PROTECTION:
-	case CSB_CC_PROTECTION:
-	case CSB_CC_PROTECTION_DUP1:
-	case CSB_CC_PROTECTION_DUP2:
-	case CSB_CC_PROTECTION_DUP3:
-	case CSB_CC_PROTECTION_DUP4:
-	case CSB_CC_PROTECTION_DUP5:
-	case CSB_CC_PROTECTION_DUP6:
-		/* should not happen, we use physical addrs */
-		CSB_ERR_ADDR(csb, "Protection error");
-		return -EPROTO;
-	case CSB_CC_PRIVILEGE:
-		/* shouldn't happen, we're in HYP mode */
-		CSB_ERR(csb, "Insufficient Privilege error");
-		return -EPROTO;
-	case CSB_CC_EXCESSIVE_DDE:
-		/* shouldn't happen, setup_ddl doesn't use many dde's */
-		CSB_ERR(csb, "Too many DDEs in DDL");
-		return -EINVAL;
-	case CSB_CC_TRANSPORT:
-	case CSB_CC_INVALID_CRB:	/* P9 or later */
-		/* shouldn't happen, we setup CRB correctly */
-		CSB_ERR(csb, "Invalid CRB");
-		return -EINVAL;
-	case CSB_CC_INVALID_DDE:	/* P9 or later */
-		/*
-		 * shouldn't happen, setup_direct/indirect_dde creates
-		 * DDE right
-		 */
-		CSB_ERR(csb, "Invalid DDE");
-		return -EINVAL;
-	case CSB_CC_SEGMENTED_DDL:
-		/* shouldn't happen, setup_ddl creates DDL right */
-		CSB_ERR(csb, "Segmented DDL error");
-		return -EINVAL;
-	case CSB_CC_DDE_OVERFLOW:
-		/* shouldn't happen, setup_ddl creates DDL right */
-		CSB_ERR(csb, "DDE overflow error");
-		return -EINVAL;
-	case CSB_CC_SESSION:
-		/* should not happen with ICSWX */
-		CSB_ERR(csb, "Session violation error");
-		return -EPROTO;
-	case CSB_CC_CHAIN:
-		/* should not happen, we don't use chained CRBs */
-		CSB_ERR(csb, "Chained CRB error");
-		return -EPROTO;
-	case CSB_CC_SEQUENCE:
-		/* should not happen, we don't use chained CRBs */
-		CSB_ERR(csb, "CRB sequence number error");
-		return -EPROTO;
-	case CSB_CC_UNKNOWN_CODE:
-		CSB_ERR(csb, "Unknown subfunction code");
-		return -EPROTO;
-
-	/* hardware errors */
-	case CSB_CC_RD_EXTERNAL:
-	case CSB_CC_RD_EXTERNAL_DUP1:
-	case CSB_CC_RD_EXTERNAL_DUP2:
-	case CSB_CC_RD_EXTERNAL_DUP3:
-		CSB_ERR_ADDR(csb, "Read error outside coprocessor");
-		return -EPROTO;
-	case CSB_CC_WR_EXTERNAL:
-		CSB_ERR_ADDR(csb, "Write error outside coprocessor");
-		return -EPROTO;
-	case CSB_CC_INTERNAL:
-		CSB_ERR(csb, "Internal error in coprocessor");
-		return -EPROTO;
-	case CSB_CC_PROVISION:
-		CSB_ERR(csb, "Storage provision error");
-		return -EPROTO;
-	case CSB_CC_HW:
-		CSB_ERR(csb, "Correctable hardware error");
-		return -EPROTO;
-	case CSB_CC_HW_EXPIRED_TIMER:	/* P9 or later */
-		CSB_ERR(csb, "Job did not finish within allowed time");
-		return -EPROTO;
-
-	default:
-		CSB_ERR(csb, "Invalid CC %d", csb->cc);
-		return -EPROTO;
-	}
-
-	/* check Completion Extension state */
-	if (csb->ce & CSB_CE_TERMINATION) {
-		CSB_ERR(csb, "CSB request was terminated");
-		return -EPROTO;
-	}
-	if (csb->ce & CSB_CE_INCOMPLETE) {
-		CSB_ERR(csb, "CSB request not complete");
-		return -EPROTO;
-	}
-	if (!(csb->ce & CSB_CE_TPBC)) {
-		CSB_ERR(csb, "TPBC not provided, unknown target length");
-		return -EPROTO;
-	}
-
-	/* successful completion */
-	pr_debug_ratelimited("Processed %u bytes in %lu us\n",
-			     be32_to_cpu(csb->count),
-			     (unsigned long)ktime_us_delta(now, start));
-
-	return 0;
-}
-
-static int nx842_config_crb(const unsigned char *in, unsigned int inlen,
-			unsigned char *out, unsigned int outlen,
-			struct nx842_workmem *wmem)
-{
-	struct coprocessor_request_block *crb;
-	struct coprocessor_status_block *csb;
-	u64 csb_addr;
-	int ret;
-
-	crb = &wmem->crb;
-	csb = &crb->csb;
-
-	/* Clear any previous values */
-	memset(crb, 0, sizeof(*crb));
-
-	/* set up DDLs */
-	ret = setup_ddl(&crb->source, wmem->ddl_in,
-			(unsigned char *)in, inlen, true);
-	if (ret)
-		return ret;
-
-	ret = setup_ddl(&crb->target, wmem->ddl_out,
-			out, outlen, false);
-	if (ret)
-		return ret;
-
-	/* set up CRB's CSB addr */
-	csb_addr = nx842_get_pa(csb) & CRB_CSB_ADDRESS;
-	csb_addr |= CRB_CSB_AT; /* Addrs are phys */
-	crb->csb_addr = cpu_to_be64(csb_addr);
-
-	return 0;
-}
-
-/**
- * nx842_exec_icswx - compress/decompress data using the 842 algorithm
- *
- * (De)compression provided by the NX842 coprocessor on IBM PowerNV systems.
- * This compresses or decompresses the provided input buffer into the provided
- * output buffer.
- *
- * Upon return from this function @outlen contains the length of the
- * output data.  If there is an error then @outlen will be 0 and an
- * error will be specified by the return code from this function.
- *
- * The @workmem buffer should only be used by one function call at a time.
- *
- * @in: input buffer pointer
- * @inlen: input buffer size
- * @out: output buffer pointer
- * @outlenp: output buffer size pointer
- * @workmem: working memory buffer pointer, size determined by
- *           nx842_powernv_driver.workmem_size
- * @fc: function code, see CCW Function Codes in nx-842.h
- *
- * Returns:
- *   0		Success, output of length @outlenp stored in the buffer at @out
- *   -ENODEV	Hardware unavailable
- *   -ENOSPC	Output buffer is to small
- *   -EMSGSIZE	Input buffer too large
- *   -EINVAL	buffer constraints do not fix nx842_constraints
- *   -EPROTO	hardware error during operation
- *   -ETIMEDOUT	hardware did not complete operation in reasonable time
- *   -EINTR	operation was aborted
- */
-static int nx842_exec_icswx(const unsigned char *in, unsigned int inlen,
-				  unsigned char *out, unsigned int *outlenp,
-				  void *workmem, int fc)
-{
-	struct coprocessor_request_block *crb;
-	struct coprocessor_status_block *csb;
-	struct nx842_workmem *wmem;
-	int ret;
-	u32 ccw;
-	unsigned int outlen = *outlenp;
-
-	wmem = PTR_ALIGN(workmem, WORKMEM_ALIGN);
-
-	*outlenp = 0;
-
-	/* shoudn't happen, we don't load without a coproc */
-	if (!nx842_ct) {
-		pr_err_ratelimited("coprocessor CT is 0");
-		return -ENODEV;
-	}
-
-	ret = nx842_config_crb(in, inlen, out, outlen, wmem);
-	if (ret)
-		return ret;
-
-	crb = &wmem->crb;
-	csb = &crb->csb;
-
-	/* set up CCW */
-	ccw = 0;
-	ccw = SET_FIELD(CCW_CT, ccw, nx842_ct);
-	ccw = SET_FIELD(CCW_CI_842, ccw, 0); /* use 0 for hw auto-selection */
-	ccw = SET_FIELD(CCW_FC_842, ccw, fc);
-
-	wmem->start = ktime_get();
-
-	/* do ICSWX */
-	ret = icswx(cpu_to_be32(ccw), crb);
-
-	pr_debug_ratelimited("icswx CR %x ccw %x crb->ccw %x\n", ret,
-			     (unsigned int)ccw,
-			     (unsigned int)be32_to_cpu(crb->ccw));
-
-	/*
-	 * NX842 coprocessor sets 3rd bit in CR register with XER[S0].
-	 * XER[S0] is the integer summary overflow bit which is nothing
-	 * to do NX. Since this bit can be set with other return values,
-	 * mask this bit.
-	 */
-	ret &= ~ICSWX_XERS0;
-
-	switch (ret) {
-	case ICSWX_INITIATED:
-		ret = wait_for_csb(wmem, csb);
-		break;
-	case ICSWX_BUSY:
-		pr_debug_ratelimited("842 Coprocessor busy\n");
-		ret = -EBUSY;
-		break;
-	case ICSWX_REJECTED:
-		pr_err_ratelimited("ICSWX rejected\n");
-		ret = -EPROTO;
-		break;
-	}
-
-	if (!ret)
-		*outlenp = be32_to_cpu(csb->count);
-
-	return ret;
-}
-
-/**
- * nx842_exec_vas - compress/decompress data using the 842 algorithm
- *
- * (De)compression provided by the NX842 coprocessor on IBM PowerNV systems.
- * This compresses or decompresses the provided input buffer into the provided
- * output buffer.
- *
- * Upon return from this function @outlen contains the length of the
- * output data.  If there is an error then @outlen will be 0 and an
- * error will be specified by the return code from this function.
- *
- * The @workmem buffer should only be used by one function call at a time.
- *
- * @in: input buffer pointer
- * @inlen: input buffer size
- * @out: output buffer pointer
- * @outlenp: output buffer size pointer
- * @workmem: working memory buffer pointer, size determined by
- *           nx842_powernv_driver.workmem_size
- * @fc: function code, see CCW Function Codes in nx-842.h
- *
- * Returns:
- *   0		Success, output of length @outlenp stored in the buffer
- *		at @out
- *   -ENODEV	Hardware unavailable
- *   -ENOSPC	Output buffer is to small
- *   -EMSGSIZE	Input buffer too large
- *   -EINVAL	buffer constraints do not fix nx842_constraints
- *   -EPROTO	hardware error during operation
- *   -ETIMEDOUT	hardware did not complete operation in reasonable time
- *   -EINTR	operation was aborted
- */
-static int nx842_exec_vas(const unsigned char *in, unsigned int inlen,
-				  unsigned char *out, unsigned int *outlenp,
-				  void *workmem, int fc)
-{
-	struct coprocessor_request_block *crb;
-	struct coprocessor_status_block *csb;
-	struct nx842_workmem *wmem;
-	struct vas_window *txwin;
-	int ret, i = 0;
-	u32 ccw;
-	unsigned int outlen = *outlenp;
-
-	wmem = PTR_ALIGN(workmem, WORKMEM_ALIGN);
-
-	*outlenp = 0;
-
-	crb = &wmem->crb;
-	csb = &crb->csb;
-
-	ret = nx842_config_crb(in, inlen, out, outlen, wmem);
-	if (ret)
-		return ret;
-
-	ccw = 0;
-	ccw = SET_FIELD(CCW_FC_842, ccw, fc);
-	crb->ccw = cpu_to_be32(ccw);
-
-	do {
-		wmem->start = ktime_get();
-		preempt_disable();
-		txwin = this_cpu_read(cpu_txwin);
-
-		/*
-		 * VAS copy CRB into L2 cache. Refer <asm/vas.h>.
-		 * @crb and @offset.
-		 */
-		vas_copy_crb(crb, 0);
-
-		/*
-		 * VAS paste previously copied CRB to NX.
-		 * @txwin, @offset and @last (must be true).
-		 */
-		ret = vas_paste_crb(txwin, 0, 1);
-		preempt_enable();
-		/*
-		 * Retry copy/paste function for VAS failures.
-		 */
-	} while (ret && (i++ < VAS_RETRIES));
-
-	if (ret) {
-		pr_err_ratelimited("VAS copy/paste failed\n");
-		return ret;
-	}
-
-	ret = wait_for_csb(wmem, csb);
-	if (!ret)
-		*outlenp = be32_to_cpu(csb->count);
-
-	return ret;
-}
-
-/**
- * nx842_powernv_compress - Compress data using the 842 algorithm
- *
- * Compression provided by the NX842 coprocessor on IBM PowerNV systems.
- * The input buffer is compressed and the result is stored in the
- * provided output buffer.
- *
- * Upon return from this function @outlen contains the length of the
- * compressed data.  If there is an error then @outlen will be 0 and an
- * error will be specified by the return code from this function.
- *
- * @in: input buffer pointer
- * @inlen: input buffer size
- * @out: output buffer pointer
- * @outlenp: output buffer size pointer
- * @workmem: working memory buffer pointer, size determined by
- *           nx842_powernv_driver.workmem_size
- *
- * Returns: see @nx842_powernv_exec()
- */
-static int nx842_powernv_compress(const unsigned char *in, unsigned int inlen,
-				  unsigned char *out, unsigned int *outlenp,
-				  void *wmem)
-{
-	return nx842_powernv_exec(in, inlen, out, outlenp,
-				      wmem, CCW_FC_842_COMP_CRC);
-}
-
-/**
- * nx842_powernv_decompress - Decompress data using the 842 algorithm
- *
- * Decompression provided by the NX842 coprocessor on IBM PowerNV systems.
- * The input buffer is decompressed and the result is stored in the
- * provided output buffer.
- *
- * Upon return from this function @outlen contains the length of the
- * decompressed data.  If there is an error then @outlen will be 0 and an
- * error will be specified by the return code from this function.
- *
- * @in: input buffer pointer
- * @inlen: input buffer size
- * @out: output buffer pointer
- * @outlenp: output buffer size pointer
- * @workmem: working memory buffer pointer, size determined by
- *           nx842_powernv_driver.workmem_size
- *
- * Returns: see @nx842_powernv_exec()
- */
-static int nx842_powernv_decompress(const unsigned char *in, unsigned int inlen,
-				    unsigned char *out, unsigned int *outlenp,
-				    void *wmem)
-{
-	return nx842_powernv_exec(in, inlen, out, outlenp,
-				      wmem, CCW_FC_842_DECOMP_CRC);
-}
-
-static inline void nx842_add_coprocs_list(struct nx842_coproc *coproc,
-					int chipid)
-{
-	coproc->chip_id = chipid;
-	INIT_LIST_HEAD(&coproc->list);
-	list_add(&coproc->list, &nx842_coprocs);
-}
-
-static struct vas_window *nx842_alloc_txwin(struct nx842_coproc *coproc)
-{
-	struct vas_window *txwin = NULL;
-	struct vas_tx_win_attr txattr;
-
-	/*
-	 * Kernel requests will be high priority. So open send
-	 * windows only for high priority RxFIFO entries.
-	 */
-	vas_init_tx_win_attr(&txattr, coproc->ct);
-	txattr.lpid = 0;	/* lpid is 0 for kernel requests */
-	txattr.pid = 0;		/* pid is 0 for kernel requests */
-
-	/*
-	 * Open a VAS send window which is used to send request to NX.
-	 */
-	txwin = vas_tx_win_open(coproc->vas.id, coproc->ct, &txattr);
-	if (IS_ERR(txwin))
-		pr_err("ibm,nx-842: Can not open TX window: %ld\n",
-				PTR_ERR(txwin));
-
-	return txwin;
-}
-
-/*
- * Identify chip ID for each CPU, open send wndow for the corresponding NX
- * engine and save txwin in percpu cpu_txwin.
- * cpu_txwin is used in copy/paste operation for each compression /
- * decompression request.
- */
-static int nx842_open_percpu_txwins(void)
-{
-	struct nx842_coproc *coproc, *n;
-	unsigned int i, chip_id;
-
-	for_each_possible_cpu(i) {
-		struct vas_window *txwin = NULL;
-
-		chip_id = cpu_to_chip_id(i);
-
-		list_for_each_entry_safe(coproc, n, &nx842_coprocs, list) {
-			/*
-			 * Kernel requests use only high priority FIFOs. So
-			 * open send windows for these FIFOs.
-			 */
-
-			if (coproc->ct != VAS_COP_TYPE_842_HIPRI)
-				continue;
-
-			if (coproc->chip_id == chip_id) {
-				txwin = nx842_alloc_txwin(coproc);
-				if (IS_ERR(txwin))
-					return PTR_ERR(txwin);
-
-				per_cpu(cpu_txwin, i) = txwin;
-				break;
-			}
-		}
-
-		if (!per_cpu(cpu_txwin, i)) {
-			/* shouldn't happen, Each chip will have NX engine */
-			pr_err("NX engine is not available for CPU %d\n", i);
-			return -EINVAL;
-		}
-	}
-
-	return 0;
-}
-
-static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
-					int vasid, int *ct)
-{
-	struct vas_window *rxwin = NULL;
-	struct vas_rx_win_attr rxattr;
-	struct nx842_coproc *coproc;
-	u32 lpid, pid, tid, fifo_size;
-	u64 rx_fifo;
-	const char *priority;
-	int ret;
-
-	ret = of_property_read_u64(dn, "rx-fifo-address", &rx_fifo);
-	if (ret) {
-		pr_err("Missing rx-fifo-address property\n");
-		return ret;
-	}
-
-	ret = of_property_read_u32(dn, "rx-fifo-size", &fifo_size);
-	if (ret) {
-		pr_err("Missing rx-fifo-size property\n");
-		return ret;
-	}
-
-	ret = of_property_read_u32(dn, "lpid", &lpid);
-	if (ret) {
-		pr_err("Missing lpid property\n");
-		return ret;
-	}
-
-	ret = of_property_read_u32(dn, "pid", &pid);
-	if (ret) {
-		pr_err("Missing pid property\n");
-		return ret;
-	}
-
-	ret = of_property_read_u32(dn, "tid", &tid);
-	if (ret) {
-		pr_err("Missing tid property\n");
-		return ret;
-	}
-
-	ret = of_property_read_string(dn, "priority", &priority);
-	if (ret) {
-		pr_err("Missing priority property\n");
-		return ret;
-	}
-
-	coproc = kzalloc(sizeof(*coproc), GFP_KERNEL);
-	if (!coproc)
-		return -ENOMEM;
-
-	if (!strcmp(priority, "High"))
-		coproc->ct = VAS_COP_TYPE_842_HIPRI;
-	else if (!strcmp(priority, "Normal"))
-		coproc->ct = VAS_COP_TYPE_842;
-	else {
-		pr_err("Invalid RxFIFO priority value\n");
-		ret =  -EINVAL;
-		goto err_out;
-	}
-
-	vas_init_rx_win_attr(&rxattr, coproc->ct);
-	rxattr.rx_fifo = (void *)rx_fifo;
-	rxattr.rx_fifo_size = fifo_size;
-	rxattr.lnotify_lpid = lpid;
-	rxattr.lnotify_pid = pid;
-	rxattr.lnotify_tid = tid;
-	/*
-	 * Maximum RX window credits can not be more than #CRBs in
-	 * RxFIFO. Otherwise, can get checkstop if RxFIFO overruns.
-	 */
-	rxattr.wcreds_max = fifo_size / CRB_SIZE;
-
-	/*
-	 * Open a VAS receice window which is used to configure RxFIFO
-	 * for NX.
-	 */
-	rxwin = vas_rx_win_open(vasid, coproc->ct, &rxattr);
-	if (IS_ERR(rxwin)) {
-		ret = PTR_ERR(rxwin);
-		pr_err("setting RxFIFO with VAS failed: %d\n",
-			ret);
-		goto err_out;
-	}
-
-	coproc->vas.rxwin = rxwin;
-	coproc->vas.id = vasid;
-	nx842_add_coprocs_list(coproc, chip_id);
-
-	/*
-	 * (lpid, pid, tid) combination has to be unique for each
-	 * coprocessor instance in the system. So to make it
-	 * unique, skiboot uses coprocessor type such as 842 or
-	 * GZIP for pid and provides this value to kernel in pid
-	 * device-tree property.
-	 */
-	*ct = pid;
-
-	return 0;
-
-err_out:
-	kfree(coproc);
-	return ret;
-}
-
-
-static int __init nx842_powernv_probe_vas(struct device_node *pn)
-{
-	struct device_node *dn;
-	int chip_id, vasid, ret = 0;
-	int nx_fifo_found = 0;
-	int uninitialized_var(ct);
-
-	chip_id = of_get_ibm_chip_id(pn);
-	if (chip_id < 0) {
-		pr_err("ibm,chip-id missing\n");
-		return -EINVAL;
-	}
-
-	vasid = chip_to_vas_id(chip_id);
-	if (vasid < 0) {
-		pr_err("Unable to map chip_id %d to vasid\n", chip_id);
-		return -EINVAL;
-	}
-
-	for_each_child_of_node(pn, dn) {
-		if (of_device_is_compatible(dn, "ibm,p9-nx-842")) {
-			ret = vas_cfg_coproc_info(dn, chip_id, vasid, &ct);
-			if (ret) {
-				of_node_put(dn);
-				return ret;
-			}
-			nx_fifo_found++;
-		}
-	}
-
-	if (!nx_fifo_found) {
-		pr_err("NX842 FIFO nodes are missing\n");
-		return -EINVAL;
-	}
-
-	/*
-	 * Initialize NX instance for both high and normal priority FIFOs.
-	 */
-	if (opal_check_token(OPAL_NX_COPROC_INIT)) {
-		ret = opal_nx_coproc_init(chip_id, ct);
-		if (ret) {
-			pr_err("Failed to initialize NX for chip(%d): %d\n",
-				chip_id, ret);
-			ret = opal_error_code(ret);
-		}
-	} else
-		pr_warn("Firmware doesn't support NX initialization\n");
-
-	return ret;
-}
-
-static int __init nx842_powernv_probe(struct device_node *dn)
-{
-	struct nx842_coproc *coproc;
-	unsigned int ct, ci;
-	int chip_id;
-
-	chip_id = of_get_ibm_chip_id(dn);
-	if (chip_id < 0) {
-		pr_err("ibm,chip-id missing\n");
-		return -EINVAL;
-	}
-
-	if (of_property_read_u32(dn, "ibm,842-coprocessor-type", &ct)) {
-		pr_err("ibm,842-coprocessor-type missing\n");
-		return -EINVAL;
-	}
-
-	if (of_property_read_u32(dn, "ibm,842-coprocessor-instance", &ci)) {
-		pr_err("ibm,842-coprocessor-instance missing\n");
-		return -EINVAL;
-	}
-
-	coproc = kzalloc(sizeof(*coproc), GFP_KERNEL);
-	if (!coproc)
-		return -ENOMEM;
-
-	coproc->ct = ct;
-	coproc->ci = ci;
-	nx842_add_coprocs_list(coproc, chip_id);
-
-	pr_info("coprocessor found on chip %d, CT %d CI %d\n", chip_id, ct, ci);
-
-	if (!nx842_ct)
-		nx842_ct = ct;
-	else if (nx842_ct != ct)
-		pr_err("NX842 chip %d, CT %d != first found CT %d\n",
-		       chip_id, ct, nx842_ct);
-
-	return 0;
-}
-
-static void nx842_delete_coprocs(void)
-{
-	struct nx842_coproc *coproc, *n;
-	struct vas_window *txwin;
-	int i;
-
-	/*
-	 * close percpu txwins that are opened for the corresponding coproc.
-	 */
-	for_each_possible_cpu(i) {
-		txwin = per_cpu(cpu_txwin, i);
-		if (txwin)
-			vas_win_close(txwin);
-
-		per_cpu(cpu_txwin, i) = 0;
-	}
-
-	list_for_each_entry_safe(coproc, n, &nx842_coprocs, list) {
-		if (coproc->vas.rxwin)
-			vas_win_close(coproc->vas.rxwin);
-
-		list_del(&coproc->list);
-		kfree(coproc);
-	}
-}
-
-static struct nx842_constraints nx842_powernv_constraints = {
-	.alignment =	DDE_BUFFER_ALIGN,
-	.multiple =	DDE_BUFFER_LAST_MULT,
-	.minimum =	DDE_BUFFER_LAST_MULT,
-	.maximum =	(DDL_LEN_MAX - 1) * PAGE_SIZE,
-};
-
-static struct nx842_driver nx842_powernv_driver = {
-	.name =		KBUILD_MODNAME,
-	.owner =	THIS_MODULE,
-	.workmem_size =	sizeof(struct nx842_workmem),
-	.constraints =	&nx842_powernv_constraints,
-	.compress =	nx842_powernv_compress,
-	.decompress =	nx842_powernv_decompress,
-};
-
-static int nx842_powernv_crypto_init(struct crypto_tfm *tfm)
-{
-	return nx842_crypto_init(tfm, &nx842_powernv_driver);
-}
-
-static struct crypto_alg nx842_powernv_alg = {
-	.cra_name		= "842",
-	.cra_driver_name	= "842-nx",
-	.cra_priority		= 300,
-	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
-	.cra_ctxsize		= sizeof(struct nx842_crypto_ctx),
-	.cra_module		= THIS_MODULE,
-	.cra_init		= nx842_powernv_crypto_init,
-	.cra_exit		= nx842_crypto_exit,
-	.cra_u			= { .compress = {
-	.coa_compress		= nx842_crypto_compress,
-	.coa_decompress		= nx842_crypto_decompress } }
-};
-
-static __init int nx842_powernv_init(void)
-{
-	struct device_node *dn;
-	int ret;
-
-	/* verify workmem size/align restrictions */
-	BUILD_BUG_ON(WORKMEM_ALIGN % CRB_ALIGN);
-	BUILD_BUG_ON(CRB_ALIGN % DDE_ALIGN);
-	BUILD_BUG_ON(CRB_SIZE % DDE_ALIGN);
-	/* verify buffer size/align restrictions */
-	BUILD_BUG_ON(PAGE_SIZE % DDE_BUFFER_ALIGN);
-	BUILD_BUG_ON(DDE_BUFFER_ALIGN % DDE_BUFFER_SIZE_MULT);
-	BUILD_BUG_ON(DDE_BUFFER_SIZE_MULT % DDE_BUFFER_LAST_MULT);
-
-	for_each_compatible_node(dn, NULL, "ibm,power9-nx") {
-		ret = nx842_powernv_probe_vas(dn);
-		if (ret) {
-			nx842_delete_coprocs();
-			of_node_put(dn);
-			return ret;
-		}
-	}
-
-	if (list_empty(&nx842_coprocs)) {
-		for_each_compatible_node(dn, NULL, "ibm,power-nx")
-			nx842_powernv_probe(dn);
-
-		if (!nx842_ct)
-			return -ENODEV;
-
-		nx842_powernv_exec = nx842_exec_icswx;
-	} else {
-		ret = nx842_open_percpu_txwins();
-		if (ret) {
-			nx842_delete_coprocs();
-			return ret;
-		}
-
-		nx842_powernv_exec = nx842_exec_vas;
-	}
-
-	ret = crypto_register_alg(&nx842_powernv_alg);
-	if (ret) {
-		nx842_delete_coprocs();
-		return ret;
-	}
-
-	return 0;
-}
-module_init(nx842_powernv_init);
-
-static void __exit nx842_powernv_exit(void)
-{
-	crypto_unregister_alg(&nx842_powernv_alg);
-
-	nx842_delete_coprocs();
-}
-module_exit(nx842_powernv_exit);
diff --git a/drivers/crypto/nx/nx-common-powernv.c b/drivers/crypto/nx/nx-common-powernv.c
new file mode 100644
index 0000000..f42881f
--- /dev/null
+++ b/drivers/crypto/nx/nx-common-powernv.c
@@ -0,0 +1,1062 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for IBM PowerNV compression accelerator
+ *
+ * Copyright (C) 2015 Dan Streetman, IBM Corp
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include "nx-842.h"
+
+#include <linux/timer.h>
+
+#include <asm/prom.h>
+#include <asm/icswx.h>
+#include <asm/vas.h>
+#include <asm/reg.h>
+#include <asm/opal-api.h>
+#include <asm/opal.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
+MODULE_DESCRIPTION("H/W Compression driver for IBM PowerNV processors");
+MODULE_ALIAS_CRYPTO("842");
+MODULE_ALIAS_CRYPTO("842-nx");
+
+#define WORKMEM_ALIGN	(CRB_ALIGN)
+#define CSB_WAIT_MAX	(5000) /* ms */
+#define VAS_RETRIES	(10)
+
+struct nx842_workmem {
+	/* Below fields must be properly aligned */
+	struct coprocessor_request_block crb; /* CRB_ALIGN align */
+	struct data_descriptor_entry ddl_in[DDL_LEN_MAX]; /* DDE_ALIGN align */
+	struct data_descriptor_entry ddl_out[DDL_LEN_MAX]; /* DDE_ALIGN align */
+	/* Above fields must be properly aligned */
+
+	ktime_t start;
+
+	char padding[WORKMEM_ALIGN]; /* unused, to allow alignment */
+} __packed __aligned(WORKMEM_ALIGN);
+
+struct nx842_coproc {
+	unsigned int chip_id;
+	unsigned int ct;
+	unsigned int ci;	/* Coprocessor instance, used with icswx */
+	struct {
+		struct vas_window *rxwin;
+		int id;
+	} vas;
+	struct list_head list;
+};
+
+/*
+ * Send the request to NX engine on the chip for the corresponding CPU
+ * where the process is executing. Use with VAS function.
+ */
+static DEFINE_PER_CPU(struct vas_window *, cpu_txwin);
+
+/* no cpu hotplug on powernv, so this list never changes after init */
+static LIST_HEAD(nx842_coprocs);
+static unsigned int nx842_ct;	/* used in icswx function */
+
+static int (*nx842_powernv_exec)(const unsigned char *in,
+				unsigned int inlen, unsigned char *out,
+				unsigned int *outlenp, void *workmem, int fc);
+
+/**
+ * setup_indirect_dde - Setup an indirect DDE
+ *
+ * The DDE is setup with the the DDE count, byte count, and address of
+ * first direct DDE in the list.
+ */
+static void setup_indirect_dde(struct data_descriptor_entry *dde,
+			       struct data_descriptor_entry *ddl,
+			       unsigned int dde_count, unsigned int byte_count)
+{
+	dde->flags = 0;
+	dde->count = dde_count;
+	dde->index = 0;
+	dde->length = cpu_to_be32(byte_count);
+	dde->address = cpu_to_be64(nx842_get_pa(ddl));
+}
+
+/**
+ * setup_direct_dde - Setup single DDE from buffer
+ *
+ * The DDE is setup with the buffer and length.  The buffer must be properly
+ * aligned.  The used length is returned.
+ * Returns:
+ *   N    Successfully set up DDE with N bytes
+ */
+static unsigned int setup_direct_dde(struct data_descriptor_entry *dde,
+				     unsigned long pa, unsigned int len)
+{
+	unsigned int l = min_t(unsigned int, len, LEN_ON_PAGE(pa));
+
+	dde->flags = 0;
+	dde->count = 0;
+	dde->index = 0;
+	dde->length = cpu_to_be32(l);
+	dde->address = cpu_to_be64(pa);
+
+	return l;
+}
+
+/**
+ * setup_ddl - Setup DDL from buffer
+ *
+ * Returns:
+ *   0		Successfully set up DDL
+ */
+static int setup_ddl(struct data_descriptor_entry *dde,
+		     struct data_descriptor_entry *ddl,
+		     unsigned char *buf, unsigned int len,
+		     bool in)
+{
+	unsigned long pa = nx842_get_pa(buf);
+	int i, ret, total_len = len;
+
+	if (!IS_ALIGNED(pa, DDE_BUFFER_ALIGN)) {
+		pr_debug("%s buffer pa 0x%lx not 0x%x-byte aligned\n",
+			 in ? "input" : "output", pa, DDE_BUFFER_ALIGN);
+		return -EINVAL;
+	}
+
+	/* only need to check last mult; since buffer must be
+	 * DDE_BUFFER_ALIGN aligned, and that is a multiple of
+	 * DDE_BUFFER_SIZE_MULT, and pre-last page DDE buffers
+	 * are guaranteed a multiple of DDE_BUFFER_SIZE_MULT.
+	 */
+	if (len % DDE_BUFFER_LAST_MULT) {
+		pr_debug("%s buffer len 0x%x not a multiple of 0x%x\n",
+			 in ? "input" : "output", len, DDE_BUFFER_LAST_MULT);
+		if (in)
+			return -EINVAL;
+		len = round_down(len, DDE_BUFFER_LAST_MULT);
+	}
+
+	/* use a single direct DDE */
+	if (len <= LEN_ON_PAGE(pa)) {
+		ret = setup_direct_dde(dde, pa, len);
+		WARN_ON(ret < len);
+		return 0;
+	}
+
+	/* use the DDL */
+	for (i = 0; i < DDL_LEN_MAX && len > 0; i++) {
+		ret = setup_direct_dde(&ddl[i], pa, len);
+		buf += ret;
+		len -= ret;
+		pa = nx842_get_pa(buf);
+	}
+
+	if (len > 0) {
+		pr_debug("0x%x total %s bytes 0x%x too many for DDL.\n",
+			 total_len, in ? "input" : "output", len);
+		if (in)
+			return -EMSGSIZE;
+		total_len -= len;
+	}
+	setup_indirect_dde(dde, ddl, i, total_len);
+
+	return 0;
+}
+
+#define CSB_ERR(csb, msg, ...)					\
+	pr_err("ERROR: " msg " : %02x %02x %02x %02x %08x\n",	\
+	       ##__VA_ARGS__, (csb)->flags,			\
+	       (csb)->cs, (csb)->cc, (csb)->ce,			\
+	       be32_to_cpu((csb)->count))
+
+#define CSB_ERR_ADDR(csb, msg, ...)				\
+	CSB_ERR(csb, msg " at %lx", ##__VA_ARGS__,		\
+		(unsigned long)be64_to_cpu((csb)->address))
+
+/**
+ * wait_for_csb
+ */
+static int wait_for_csb(struct nx842_workmem *wmem,
+			struct coprocessor_status_block *csb)
+{
+	ktime_t start = wmem->start, now = ktime_get();
+	ktime_t timeout = ktime_add_ms(start, CSB_WAIT_MAX);
+
+	while (!(READ_ONCE(csb->flags) & CSB_V)) {
+		cpu_relax();
+		now = ktime_get();
+		if (ktime_after(now, timeout))
+			break;
+	}
+
+	/* hw has updated csb and output buffer */
+	barrier();
+
+	/* check CSB flags */
+	if (!(csb->flags & CSB_V)) {
+		CSB_ERR(csb, "CSB still not valid after %ld us, giving up",
+			(long)ktime_us_delta(now, start));
+		return -ETIMEDOUT;
+	}
+	if (csb->flags & CSB_F) {
+		CSB_ERR(csb, "Invalid CSB format");
+		return -EPROTO;
+	}
+	if (csb->flags & CSB_CH) {
+		CSB_ERR(csb, "Invalid CSB chaining state");
+		return -EPROTO;
+	}
+
+	/* verify CSB completion sequence is 0 */
+	if (csb->cs) {
+		CSB_ERR(csb, "Invalid CSB completion sequence");
+		return -EPROTO;
+	}
+
+	/* check CSB Completion Code */
+	switch (csb->cc) {
+	/* no error */
+	case CSB_CC_SUCCESS:
+		break;
+	case CSB_CC_TPBC_GT_SPBC:
+		/* not an error, but the compressed data is
+		 * larger than the uncompressed data :(
+		 */
+		break;
+
+	/* input data errors */
+	case CSB_CC_OPERAND_OVERLAP:
+		/* input and output buffers overlap */
+		CSB_ERR(csb, "Operand Overlap error");
+		return -EINVAL;
+	case CSB_CC_INVALID_OPERAND:
+		CSB_ERR(csb, "Invalid operand");
+		return -EINVAL;
+	case CSB_CC_NOSPC:
+		/* output buffer too small */
+		return -ENOSPC;
+	case CSB_CC_ABORT:
+		CSB_ERR(csb, "Function aborted");
+		return -EINTR;
+	case CSB_CC_CRC_MISMATCH:
+		CSB_ERR(csb, "CRC mismatch");
+		return -EINVAL;
+	case CSB_CC_TEMPL_INVALID:
+		CSB_ERR(csb, "Compressed data template invalid");
+		return -EINVAL;
+	case CSB_CC_TEMPL_OVERFLOW:
+		CSB_ERR(csb, "Compressed data template shows data past end");
+		return -EINVAL;
+	case CSB_CC_EXCEED_BYTE_COUNT:	/* P9 or later */
+		/*
+		 * DDE byte count exceeds the limit specified in Maximum
+		 * byte count register.
+		 */
+		CSB_ERR(csb, "DDE byte count exceeds the limit");
+		return -EINVAL;
+
+	/* these should not happen */
+	case CSB_CC_INVALID_ALIGN:
+		/* setup_ddl should have detected this */
+		CSB_ERR_ADDR(csb, "Invalid alignment");
+		return -EINVAL;
+	case CSB_CC_DATA_LENGTH:
+		/* setup_ddl should have detected this */
+		CSB_ERR(csb, "Invalid data length");
+		return -EINVAL;
+	case CSB_CC_WR_TRANSLATION:
+	case CSB_CC_TRANSLATION:
+	case CSB_CC_TRANSLATION_DUP1:
+	case CSB_CC_TRANSLATION_DUP2:
+	case CSB_CC_TRANSLATION_DUP3:
+	case CSB_CC_TRANSLATION_DUP4:
+	case CSB_CC_TRANSLATION_DUP5:
+	case CSB_CC_TRANSLATION_DUP6:
+		/* should not happen, we use physical addrs */
+		CSB_ERR_ADDR(csb, "Translation error");
+		return -EPROTO;
+	case CSB_CC_WR_PROTECTION:
+	case CSB_CC_PROTECTION:
+	case CSB_CC_PROTECTION_DUP1:
+	case CSB_CC_PROTECTION_DUP2:
+	case CSB_CC_PROTECTION_DUP3:
+	case CSB_CC_PROTECTION_DUP4:
+	case CSB_CC_PROTECTION_DUP5:
+	case CSB_CC_PROTECTION_DUP6:
+		/* should not happen, we use physical addrs */
+		CSB_ERR_ADDR(csb, "Protection error");
+		return -EPROTO;
+	case CSB_CC_PRIVILEGE:
+		/* shouldn't happen, we're in HYP mode */
+		CSB_ERR(csb, "Insufficient Privilege error");
+		return -EPROTO;
+	case CSB_CC_EXCESSIVE_DDE:
+		/* shouldn't happen, setup_ddl doesn't use many dde's */
+		CSB_ERR(csb, "Too many DDEs in DDL");
+		return -EINVAL;
+	case CSB_CC_TRANSPORT:
+	case CSB_CC_INVALID_CRB:	/* P9 or later */
+		/* shouldn't happen, we setup CRB correctly */
+		CSB_ERR(csb, "Invalid CRB");
+		return -EINVAL;
+	case CSB_CC_INVALID_DDE:	/* P9 or later */
+		/*
+		 * shouldn't happen, setup_direct/indirect_dde creates
+		 * DDE right
+		 */
+		CSB_ERR(csb, "Invalid DDE");
+		return -EINVAL;
+	case CSB_CC_SEGMENTED_DDL:
+		/* shouldn't happen, setup_ddl creates DDL right */
+		CSB_ERR(csb, "Segmented DDL error");
+		return -EINVAL;
+	case CSB_CC_DDE_OVERFLOW:
+		/* shouldn't happen, setup_ddl creates DDL right */
+		CSB_ERR(csb, "DDE overflow error");
+		return -EINVAL;
+	case CSB_CC_SESSION:
+		/* should not happen with ICSWX */
+		CSB_ERR(csb, "Session violation error");
+		return -EPROTO;
+	case CSB_CC_CHAIN:
+		/* should not happen, we don't use chained CRBs */
+		CSB_ERR(csb, "Chained CRB error");
+		return -EPROTO;
+	case CSB_CC_SEQUENCE:
+		/* should not happen, we don't use chained CRBs */
+		CSB_ERR(csb, "CRB sequence number error");
+		return -EPROTO;
+	case CSB_CC_UNKNOWN_CODE:
+		CSB_ERR(csb, "Unknown subfunction code");
+		return -EPROTO;
+
+	/* hardware errors */
+	case CSB_CC_RD_EXTERNAL:
+	case CSB_CC_RD_EXTERNAL_DUP1:
+	case CSB_CC_RD_EXTERNAL_DUP2:
+	case CSB_CC_RD_EXTERNAL_DUP3:
+		CSB_ERR_ADDR(csb, "Read error outside coprocessor");
+		return -EPROTO;
+	case CSB_CC_WR_EXTERNAL:
+		CSB_ERR_ADDR(csb, "Write error outside coprocessor");
+		return -EPROTO;
+	case CSB_CC_INTERNAL:
+		CSB_ERR(csb, "Internal error in coprocessor");
+		return -EPROTO;
+	case CSB_CC_PROVISION:
+		CSB_ERR(csb, "Storage provision error");
+		return -EPROTO;
+	case CSB_CC_HW:
+		CSB_ERR(csb, "Correctable hardware error");
+		return -EPROTO;
+	case CSB_CC_HW_EXPIRED_TIMER:	/* P9 or later */
+		CSB_ERR(csb, "Job did not finish within allowed time");
+		return -EPROTO;
+
+	default:
+		CSB_ERR(csb, "Invalid CC %d", csb->cc);
+		return -EPROTO;
+	}
+
+	/* check Completion Extension state */
+	if (csb->ce & CSB_CE_TERMINATION) {
+		CSB_ERR(csb, "CSB request was terminated");
+		return -EPROTO;
+	}
+	if (csb->ce & CSB_CE_INCOMPLETE) {
+		CSB_ERR(csb, "CSB request not complete");
+		return -EPROTO;
+	}
+	if (!(csb->ce & CSB_CE_TPBC)) {
+		CSB_ERR(csb, "TPBC not provided, unknown target length");
+		return -EPROTO;
+	}
+
+	/* successful completion */
+	pr_debug_ratelimited("Processed %u bytes in %lu us\n",
+			     be32_to_cpu(csb->count),
+			     (unsigned long)ktime_us_delta(now, start));
+
+	return 0;
+}
+
+static int nx842_config_crb(const unsigned char *in, unsigned int inlen,
+			unsigned char *out, unsigned int outlen,
+			struct nx842_workmem *wmem)
+{
+	struct coprocessor_request_block *crb;
+	struct coprocessor_status_block *csb;
+	u64 csb_addr;
+	int ret;
+
+	crb = &wmem->crb;
+	csb = &crb->csb;
+
+	/* Clear any previous values */
+	memset(crb, 0, sizeof(*crb));
+
+	/* set up DDLs */
+	ret = setup_ddl(&crb->source, wmem->ddl_in,
+			(unsigned char *)in, inlen, true);
+	if (ret)
+		return ret;
+
+	ret = setup_ddl(&crb->target, wmem->ddl_out,
+			out, outlen, false);
+	if (ret)
+		return ret;
+
+	/* set up CRB's CSB addr */
+	csb_addr = nx842_get_pa(csb) & CRB_CSB_ADDRESS;
+	csb_addr |= CRB_CSB_AT; /* Addrs are phys */
+	crb->csb_addr = cpu_to_be64(csb_addr);
+
+	return 0;
+}
+
+/**
+ * nx842_exec_icswx - compress/decompress data using the 842 algorithm
+ *
+ * (De)compression provided by the NX842 coprocessor on IBM PowerNV systems.
+ * This compresses or decompresses the provided input buffer into the provided
+ * output buffer.
+ *
+ * Upon return from this function @outlen contains the length of the
+ * output data.  If there is an error then @outlen will be 0 and an
+ * error will be specified by the return code from this function.
+ *
+ * The @workmem buffer should only be used by one function call at a time.
+ *
+ * @in: input buffer pointer
+ * @inlen: input buffer size
+ * @out: output buffer pointer
+ * @outlenp: output buffer size pointer
+ * @workmem: working memory buffer pointer, size determined by
+ *           nx842_powernv_driver.workmem_size
+ * @fc: function code, see CCW Function Codes in nx-842.h
+ *
+ * Returns:
+ *   0		Success, output of length @outlenp stored in the buffer at @out
+ *   -ENODEV	Hardware unavailable
+ *   -ENOSPC	Output buffer is to small
+ *   -EMSGSIZE	Input buffer too large
+ *   -EINVAL	buffer constraints do not fix nx842_constraints
+ *   -EPROTO	hardware error during operation
+ *   -ETIMEDOUT	hardware did not complete operation in reasonable time
+ *   -EINTR	operation was aborted
+ */
+static int nx842_exec_icswx(const unsigned char *in, unsigned int inlen,
+				  unsigned char *out, unsigned int *outlenp,
+				  void *workmem, int fc)
+{
+	struct coprocessor_request_block *crb;
+	struct coprocessor_status_block *csb;
+	struct nx842_workmem *wmem;
+	int ret;
+	u32 ccw;
+	unsigned int outlen = *outlenp;
+
+	wmem = PTR_ALIGN(workmem, WORKMEM_ALIGN);
+
+	*outlenp = 0;
+
+	/* shoudn't happen, we don't load without a coproc */
+	if (!nx842_ct) {
+		pr_err_ratelimited("coprocessor CT is 0");
+		return -ENODEV;
+	}
+
+	ret = nx842_config_crb(in, inlen, out, outlen, wmem);
+	if (ret)
+		return ret;
+
+	crb = &wmem->crb;
+	csb = &crb->csb;
+
+	/* set up CCW */
+	ccw = 0;
+	ccw = SET_FIELD(CCW_CT, ccw, nx842_ct);
+	ccw = SET_FIELD(CCW_CI_842, ccw, 0); /* use 0 for hw auto-selection */
+	ccw = SET_FIELD(CCW_FC_842, ccw, fc);
+
+	wmem->start = ktime_get();
+
+	/* do ICSWX */
+	ret = icswx(cpu_to_be32(ccw), crb);
+
+	pr_debug_ratelimited("icswx CR %x ccw %x crb->ccw %x\n", ret,
+			     (unsigned int)ccw,
+			     (unsigned int)be32_to_cpu(crb->ccw));
+
+	/*
+	 * NX842 coprocessor sets 3rd bit in CR register with XER[S0].
+	 * XER[S0] is the integer summary overflow bit which is nothing
+	 * to do NX. Since this bit can be set with other return values,
+	 * mask this bit.
+	 */
+	ret &= ~ICSWX_XERS0;
+
+	switch (ret) {
+	case ICSWX_INITIATED:
+		ret = wait_for_csb(wmem, csb);
+		break;
+	case ICSWX_BUSY:
+		pr_debug_ratelimited("842 Coprocessor busy\n");
+		ret = -EBUSY;
+		break;
+	case ICSWX_REJECTED:
+		pr_err_ratelimited("ICSWX rejected\n");
+		ret = -EPROTO;
+		break;
+	}
+
+	if (!ret)
+		*outlenp = be32_to_cpu(csb->count);
+
+	return ret;
+}
+
+/**
+ * nx842_exec_vas - compress/decompress data using the 842 algorithm
+ *
+ * (De)compression provided by the NX842 coprocessor on IBM PowerNV systems.
+ * This compresses or decompresses the provided input buffer into the provided
+ * output buffer.
+ *
+ * Upon return from this function @outlen contains the length of the
+ * output data.  If there is an error then @outlen will be 0 and an
+ * error will be specified by the return code from this function.
+ *
+ * The @workmem buffer should only be used by one function call at a time.
+ *
+ * @in: input buffer pointer
+ * @inlen: input buffer size
+ * @out: output buffer pointer
+ * @outlenp: output buffer size pointer
+ * @workmem: working memory buffer pointer, size determined by
+ *           nx842_powernv_driver.workmem_size
+ * @fc: function code, see CCW Function Codes in nx-842.h
+ *
+ * Returns:
+ *   0		Success, output of length @outlenp stored in the buffer
+ *		at @out
+ *   -ENODEV	Hardware unavailable
+ *   -ENOSPC	Output buffer is to small
+ *   -EMSGSIZE	Input buffer too large
+ *   -EINVAL	buffer constraints do not fix nx842_constraints
+ *   -EPROTO	hardware error during operation
+ *   -ETIMEDOUT	hardware did not complete operation in reasonable time
+ *   -EINTR	operation was aborted
+ */
+static int nx842_exec_vas(const unsigned char *in, unsigned int inlen,
+				  unsigned char *out, unsigned int *outlenp,
+				  void *workmem, int fc)
+{
+	struct coprocessor_request_block *crb;
+	struct coprocessor_status_block *csb;
+	struct nx842_workmem *wmem;
+	struct vas_window *txwin;
+	int ret, i = 0;
+	u32 ccw;
+	unsigned int outlen = *outlenp;
+
+	wmem = PTR_ALIGN(workmem, WORKMEM_ALIGN);
+
+	*outlenp = 0;
+
+	crb = &wmem->crb;
+	csb = &crb->csb;
+
+	ret = nx842_config_crb(in, inlen, out, outlen, wmem);
+	if (ret)
+		return ret;
+
+	ccw = 0;
+	ccw = SET_FIELD(CCW_FC_842, ccw, fc);
+	crb->ccw = cpu_to_be32(ccw);
+
+	do {
+		wmem->start = ktime_get();
+		preempt_disable();
+		txwin = this_cpu_read(cpu_txwin);
+
+		/*
+		 * VAS copy CRB into L2 cache. Refer <asm/vas.h>.
+		 * @crb and @offset.
+		 */
+		vas_copy_crb(crb, 0);
+
+		/*
+		 * VAS paste previously copied CRB to NX.
+		 * @txwin, @offset and @last (must be true).
+		 */
+		ret = vas_paste_crb(txwin, 0, 1);
+		preempt_enable();
+		/*
+		 * Retry copy/paste function for VAS failures.
+		 */
+	} while (ret && (i++ < VAS_RETRIES));
+
+	if (ret) {
+		pr_err_ratelimited("VAS copy/paste failed\n");
+		return ret;
+	}
+
+	ret = wait_for_csb(wmem, csb);
+	if (!ret)
+		*outlenp = be32_to_cpu(csb->count);
+
+	return ret;
+}
+
+/**
+ * nx842_powernv_compress - Compress data using the 842 algorithm
+ *
+ * Compression provided by the NX842 coprocessor on IBM PowerNV systems.
+ * The input buffer is compressed and the result is stored in the
+ * provided output buffer.
+ *
+ * Upon return from this function @outlen contains the length of the
+ * compressed data.  If there is an error then @outlen will be 0 and an
+ * error will be specified by the return code from this function.
+ *
+ * @in: input buffer pointer
+ * @inlen: input buffer size
+ * @out: output buffer pointer
+ * @outlenp: output buffer size pointer
+ * @workmem: working memory buffer pointer, size determined by
+ *           nx842_powernv_driver.workmem_size
+ *
+ * Returns: see @nx842_powernv_exec()
+ */
+static int nx842_powernv_compress(const unsigned char *in, unsigned int inlen,
+				  unsigned char *out, unsigned int *outlenp,
+				  void *wmem)
+{
+	return nx842_powernv_exec(in, inlen, out, outlenp,
+				      wmem, CCW_FC_842_COMP_CRC);
+}
+
+/**
+ * nx842_powernv_decompress - Decompress data using the 842 algorithm
+ *
+ * Decompression provided by the NX842 coprocessor on IBM PowerNV systems.
+ * The input buffer is decompressed and the result is stored in the
+ * provided output buffer.
+ *
+ * Upon return from this function @outlen contains the length of the
+ * decompressed data.  If there is an error then @outlen will be 0 and an
+ * error will be specified by the return code from this function.
+ *
+ * @in: input buffer pointer
+ * @inlen: input buffer size
+ * @out: output buffer pointer
+ * @outlenp: output buffer size pointer
+ * @workmem: working memory buffer pointer, size determined by
+ *           nx842_powernv_driver.workmem_size
+ *
+ * Returns: see @nx842_powernv_exec()
+ */
+static int nx842_powernv_decompress(const unsigned char *in, unsigned int inlen,
+				    unsigned char *out, unsigned int *outlenp,
+				    void *wmem)
+{
+	return nx842_powernv_exec(in, inlen, out, outlenp,
+				      wmem, CCW_FC_842_DECOMP_CRC);
+}
+
+static inline void nx842_add_coprocs_list(struct nx842_coproc *coproc,
+					int chipid)
+{
+	coproc->chip_id = chipid;
+	INIT_LIST_HEAD(&coproc->list);
+	list_add(&coproc->list, &nx842_coprocs);
+}
+
+static struct vas_window *nx842_alloc_txwin(struct nx842_coproc *coproc)
+{
+	struct vas_window *txwin = NULL;
+	struct vas_tx_win_attr txattr;
+
+	/*
+	 * Kernel requests will be high priority. So open send
+	 * windows only for high priority RxFIFO entries.
+	 */
+	vas_init_tx_win_attr(&txattr, coproc->ct);
+	txattr.lpid = 0;	/* lpid is 0 for kernel requests */
+	txattr.pid = 0;		/* pid is 0 for kernel requests */
+
+	/*
+	 * Open a VAS send window which is used to send request to NX.
+	 */
+	txwin = vas_tx_win_open(coproc->vas.id, coproc->ct, &txattr);
+	if (IS_ERR(txwin))
+		pr_err("ibm,nx-842: Can not open TX window: %ld\n",
+				PTR_ERR(txwin));
+
+	return txwin;
+}
+
+/*
+ * Identify chip ID for each CPU, open send wndow for the corresponding NX
+ * engine and save txwin in percpu cpu_txwin.
+ * cpu_txwin is used in copy/paste operation for each compression /
+ * decompression request.
+ */
+static int nx842_open_percpu_txwins(void)
+{
+	struct nx842_coproc *coproc, *n;
+	unsigned int i, chip_id;
+
+	for_each_possible_cpu(i) {
+		struct vas_window *txwin = NULL;
+
+		chip_id = cpu_to_chip_id(i);
+
+		list_for_each_entry_safe(coproc, n, &nx842_coprocs, list) {
+			/*
+			 * Kernel requests use only high priority FIFOs. So
+			 * open send windows for these FIFOs.
+			 */
+
+			if (coproc->ct != VAS_COP_TYPE_842_HIPRI)
+				continue;
+
+			if (coproc->chip_id == chip_id) {
+				txwin = nx842_alloc_txwin(coproc);
+				if (IS_ERR(txwin))
+					return PTR_ERR(txwin);
+
+				per_cpu(cpu_txwin, i) = txwin;
+				break;
+			}
+		}
+
+		if (!per_cpu(cpu_txwin, i)) {
+			/* shouldn't happen, Each chip will have NX engine */
+			pr_err("NX engine is not available for CPU %d\n", i);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
+					int vasid, int *ct)
+{
+	struct vas_window *rxwin = NULL;
+	struct vas_rx_win_attr rxattr;
+	struct nx842_coproc *coproc;
+	u32 lpid, pid, tid, fifo_size;
+	u64 rx_fifo;
+	const char *priority;
+	int ret;
+
+	ret = of_property_read_u64(dn, "rx-fifo-address", &rx_fifo);
+	if (ret) {
+		pr_err("Missing rx-fifo-address property\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(dn, "rx-fifo-size", &fifo_size);
+	if (ret) {
+		pr_err("Missing rx-fifo-size property\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(dn, "lpid", &lpid);
+	if (ret) {
+		pr_err("Missing lpid property\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(dn, "pid", &pid);
+	if (ret) {
+		pr_err("Missing pid property\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(dn, "tid", &tid);
+	if (ret) {
+		pr_err("Missing tid property\n");
+		return ret;
+	}
+
+	ret = of_property_read_string(dn, "priority", &priority);
+	if (ret) {
+		pr_err("Missing priority property\n");
+		return ret;
+	}
+
+	coproc = kzalloc(sizeof(*coproc), GFP_KERNEL);
+	if (!coproc)
+		return -ENOMEM;
+
+	if (!strcmp(priority, "High"))
+		coproc->ct = VAS_COP_TYPE_842_HIPRI;
+	else if (!strcmp(priority, "Normal"))
+		coproc->ct = VAS_COP_TYPE_842;
+	else {
+		pr_err("Invalid RxFIFO priority value\n");
+		ret =  -EINVAL;
+		goto err_out;
+	}
+
+	vas_init_rx_win_attr(&rxattr, coproc->ct);
+	rxattr.rx_fifo = (void *)rx_fifo;
+	rxattr.rx_fifo_size = fifo_size;
+	rxattr.lnotify_lpid = lpid;
+	rxattr.lnotify_pid = pid;
+	rxattr.lnotify_tid = tid;
+	/*
+	 * Maximum RX window credits can not be more than #CRBs in
+	 * RxFIFO. Otherwise, can get checkstop if RxFIFO overruns.
+	 */
+	rxattr.wcreds_max = fifo_size / CRB_SIZE;
+
+	/*
+	 * Open a VAS receice window which is used to configure RxFIFO
+	 * for NX.
+	 */
+	rxwin = vas_rx_win_open(vasid, coproc->ct, &rxattr);
+	if (IS_ERR(rxwin)) {
+		ret = PTR_ERR(rxwin);
+		pr_err("setting RxFIFO with VAS failed: %d\n",
+			ret);
+		goto err_out;
+	}
+
+	coproc->vas.rxwin = rxwin;
+	coproc->vas.id = vasid;
+	nx842_add_coprocs_list(coproc, chip_id);
+
+	/*
+	 * (lpid, pid, tid) combination has to be unique for each
+	 * coprocessor instance in the system. So to make it
+	 * unique, skiboot uses coprocessor type such as 842 or
+	 * GZIP for pid and provides this value to kernel in pid
+	 * device-tree property.
+	 */
+	*ct = pid;
+
+	return 0;
+
+err_out:
+	kfree(coproc);
+	return ret;
+}
+
+
+static int __init nx842_powernv_probe_vas(struct device_node *pn)
+{
+	struct device_node *dn;
+	int chip_id, vasid, ret = 0;
+	int nx_fifo_found = 0;
+	int uninitialized_var(ct);
+
+	chip_id = of_get_ibm_chip_id(pn);
+	if (chip_id < 0) {
+		pr_err("ibm,chip-id missing\n");
+		return -EINVAL;
+	}
+
+	vasid = chip_to_vas_id(chip_id);
+	if (vasid < 0) {
+		pr_err("Unable to map chip_id %d to vasid\n", chip_id);
+		return -EINVAL;
+	}
+
+	for_each_child_of_node(pn, dn) {
+		if (of_device_is_compatible(dn, "ibm,p9-nx-842")) {
+			ret = vas_cfg_coproc_info(dn, chip_id, vasid, &ct);
+			if (ret) {
+				of_node_put(dn);
+				return ret;
+			}
+			nx_fifo_found++;
+		}
+	}
+
+	if (!nx_fifo_found) {
+		pr_err("NX842 FIFO nodes are missing\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Initialize NX instance for both high and normal priority FIFOs.
+	 */
+	if (opal_check_token(OPAL_NX_COPROC_INIT)) {
+		ret = opal_nx_coproc_init(chip_id, ct);
+		if (ret) {
+			pr_err("Failed to initialize NX for chip(%d): %d\n",
+				chip_id, ret);
+			ret = opal_error_code(ret);
+		}
+	} else
+		pr_warn("Firmware doesn't support NX initialization\n");
+
+	return ret;
+}
+
+static int __init nx842_powernv_probe(struct device_node *dn)
+{
+	struct nx842_coproc *coproc;
+	unsigned int ct, ci;
+	int chip_id;
+
+	chip_id = of_get_ibm_chip_id(dn);
+	if (chip_id < 0) {
+		pr_err("ibm,chip-id missing\n");
+		return -EINVAL;
+	}
+
+	if (of_property_read_u32(dn, "ibm,842-coprocessor-type", &ct)) {
+		pr_err("ibm,842-coprocessor-type missing\n");
+		return -EINVAL;
+	}
+
+	if (of_property_read_u32(dn, "ibm,842-coprocessor-instance", &ci)) {
+		pr_err("ibm,842-coprocessor-instance missing\n");
+		return -EINVAL;
+	}
+
+	coproc = kzalloc(sizeof(*coproc), GFP_KERNEL);
+	if (!coproc)
+		return -ENOMEM;
+
+	coproc->ct = ct;
+	coproc->ci = ci;
+	nx842_add_coprocs_list(coproc, chip_id);
+
+	pr_info("coprocessor found on chip %d, CT %d CI %d\n", chip_id, ct, ci);
+
+	if (!nx842_ct)
+		nx842_ct = ct;
+	else if (nx842_ct != ct)
+		pr_err("NX842 chip %d, CT %d != first found CT %d\n",
+		       chip_id, ct, nx842_ct);
+
+	return 0;
+}
+
+static void nx842_delete_coprocs(void)
+{
+	struct nx842_coproc *coproc, *n;
+	struct vas_window *txwin;
+	int i;
+
+	/*
+	 * close percpu txwins that are opened for the corresponding coproc.
+	 */
+	for_each_possible_cpu(i) {
+		txwin = per_cpu(cpu_txwin, i);
+		if (txwin)
+			vas_win_close(txwin);
+
+		per_cpu(cpu_txwin, i) = 0;
+	}
+
+	list_for_each_entry_safe(coproc, n, &nx842_coprocs, list) {
+		if (coproc->vas.rxwin)
+			vas_win_close(coproc->vas.rxwin);
+
+		list_del(&coproc->list);
+		kfree(coproc);
+	}
+}
+
+static struct nx842_constraints nx842_powernv_constraints = {
+	.alignment =	DDE_BUFFER_ALIGN,
+	.multiple =	DDE_BUFFER_LAST_MULT,
+	.minimum =	DDE_BUFFER_LAST_MULT,
+	.maximum =	(DDL_LEN_MAX - 1) * PAGE_SIZE,
+};
+
+static struct nx842_driver nx842_powernv_driver = {
+	.name =		KBUILD_MODNAME,
+	.owner =	THIS_MODULE,
+	.workmem_size =	sizeof(struct nx842_workmem),
+	.constraints =	&nx842_powernv_constraints,
+	.compress =	nx842_powernv_compress,
+	.decompress =	nx842_powernv_decompress,
+};
+
+static int nx842_powernv_crypto_init(struct crypto_tfm *tfm)
+{
+	return nx842_crypto_init(tfm, &nx842_powernv_driver);
+}
+
+static struct crypto_alg nx842_powernv_alg = {
+	.cra_name		= "842",
+	.cra_driver_name	= "842-nx",
+	.cra_priority		= 300,
+	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
+	.cra_ctxsize		= sizeof(struct nx842_crypto_ctx),
+	.cra_module		= THIS_MODULE,
+	.cra_init		= nx842_powernv_crypto_init,
+	.cra_exit		= nx842_crypto_exit,
+	.cra_u			= { .compress = {
+	.coa_compress		= nx842_crypto_compress,
+	.coa_decompress		= nx842_crypto_decompress } }
+};
+
+static __init int nx842_powernv_init(void)
+{
+	struct device_node *dn;
+	int ret;
+
+	/* verify workmem size/align restrictions */
+	BUILD_BUG_ON(WORKMEM_ALIGN % CRB_ALIGN);
+	BUILD_BUG_ON(CRB_ALIGN % DDE_ALIGN);
+	BUILD_BUG_ON(CRB_SIZE % DDE_ALIGN);
+	/* verify buffer size/align restrictions */
+	BUILD_BUG_ON(PAGE_SIZE % DDE_BUFFER_ALIGN);
+	BUILD_BUG_ON(DDE_BUFFER_ALIGN % DDE_BUFFER_SIZE_MULT);
+	BUILD_BUG_ON(DDE_BUFFER_SIZE_MULT % DDE_BUFFER_LAST_MULT);
+
+	for_each_compatible_node(dn, NULL, "ibm,power9-nx") {
+		ret = nx842_powernv_probe_vas(dn);
+		if (ret) {
+			nx842_delete_coprocs();
+			of_node_put(dn);
+			return ret;
+		}
+	}
+
+	if (list_empty(&nx842_coprocs)) {
+		for_each_compatible_node(dn, NULL, "ibm,power-nx")
+			nx842_powernv_probe(dn);
+
+		if (!nx842_ct)
+			return -ENODEV;
+
+		nx842_powernv_exec = nx842_exec_icswx;
+	} else {
+		ret = nx842_open_percpu_txwins();
+		if (ret) {
+			nx842_delete_coprocs();
+			return ret;
+		}
+
+		nx842_powernv_exec = nx842_exec_vas;
+	}
+
+	ret = crypto_register_alg(&nx842_powernv_alg);
+	if (ret) {
+		nx842_delete_coprocs();
+		return ret;
+	}
+
+	return 0;
+}
+module_init(nx842_powernv_init);
+
+static void __exit nx842_powernv_exit(void)
+{
+	crypto_unregister_alg(&nx842_powernv_alg);
+
+	nx842_delete_coprocs();
+}
+module_exit(nx842_powernv_exit);
-- 
1.8.3.1

[PATCH v3 6/9] crypto/NX: Make enable code generic to add new GZIP compression type

[Haren Myneni]

Make setup and enable code generic to support new GZIP compression type.
Changed nx842 reference to nx and moved some code to new functions.
Functionality is not changed except sparse warning fix - setting NULL
instead of 0 for per_cpu send window in nx_delete_coprocs().

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 drivers/crypto/nx/nx-common-powernv.c | 161 +++++++++++++++++++++-------------
 1 file changed, 101 insertions(+), 60 deletions(-)

diff --git a/drivers/crypto/nx/nx-common-powernv.c b/drivers/crypto/nx/nx-common-powernv.c
index f42881f..82dfa60 100644
--- a/drivers/crypto/nx/nx-common-powernv.c
+++ b/drivers/crypto/nx/nx-common-powernv.c
@@ -40,9 +40,9 @@ struct nx842_workmem {
 	char padding[WORKMEM_ALIGN]; /* unused, to allow alignment */
 } __packed __aligned(WORKMEM_ALIGN);
 
-struct nx842_coproc {
+struct nx_coproc {
 	unsigned int chip_id;
-	unsigned int ct;
+	unsigned int ct;	/* Can be 842 or GZIP high/normal*/
 	unsigned int ci;	/* Coprocessor instance, used with icswx */
 	struct {
 		struct vas_window *rxwin;
@@ -58,9 +58,15 @@ struct nx842_coproc {
 static DEFINE_PER_CPU(struct vas_window *, cpu_txwin);
 
 /* no cpu hotplug on powernv, so this list never changes after init */
-static LIST_HEAD(nx842_coprocs);
+static LIST_HEAD(nx_coprocs);
 static unsigned int nx842_ct;	/* used in icswx function */
 
+/*
+ * Using same values as in skiboot or coprocessor type representing
+ * in NX workbook.
+ */
+#define NX_CT_842	(3)
+
 static int (*nx842_powernv_exec)(const unsigned char *in,
 				unsigned int inlen, unsigned char *out,
 				unsigned int *outlenp, void *workmem, int fc);
@@ -666,15 +672,15 @@ static int nx842_powernv_decompress(const unsigned char *in, unsigned int inlen,
 				      wmem, CCW_FC_842_DECOMP_CRC);
 }
 
-static inline void nx842_add_coprocs_list(struct nx842_coproc *coproc,
+static inline void nx_add_coprocs_list(struct nx_coproc *coproc,
 					int chipid)
 {
 	coproc->chip_id = chipid;
 	INIT_LIST_HEAD(&coproc->list);
-	list_add(&coproc->list, &nx842_coprocs);
+	list_add(&coproc->list, &nx_coprocs);
 }
 
-static struct vas_window *nx842_alloc_txwin(struct nx842_coproc *coproc)
+static struct vas_window *nx_alloc_txwin(struct nx_coproc *coproc)
 {
 	struct vas_window *txwin = NULL;
 	struct vas_tx_win_attr txattr;
@@ -704,9 +710,9 @@ static struct vas_window *nx842_alloc_txwin(struct nx842_coproc *coproc)
  * cpu_txwin is used in copy/paste operation for each compression /
  * decompression request.
  */
-static int nx842_open_percpu_txwins(void)
+static int nx_open_percpu_txwins(void)
 {
-	struct nx842_coproc *coproc, *n;
+	struct nx_coproc *coproc, *n;
 	unsigned int i, chip_id;
 
 	for_each_possible_cpu(i) {
@@ -714,17 +720,18 @@ static int nx842_open_percpu_txwins(void)
 
 		chip_id = cpu_to_chip_id(i);
 
-		list_for_each_entry_safe(coproc, n, &nx842_coprocs, list) {
+		list_for_each_entry_safe(coproc, n, &nx_coprocs, list) {
 			/*
 			 * Kernel requests use only high priority FIFOs. So
 			 * open send windows for these FIFOs.
+			 * GZIP is not supported in kernel right now.
 			 */
 
 			if (coproc->ct != VAS_COP_TYPE_842_HIPRI)
 				continue;
 
 			if (coproc->chip_id == chip_id) {
-				txwin = nx842_alloc_txwin(coproc);
+				txwin = nx_alloc_txwin(coproc);
 				if (IS_ERR(txwin))
 					return PTR_ERR(txwin);
 
@@ -743,13 +750,28 @@ static int nx842_open_percpu_txwins(void)
 	return 0;
 }
 
+static int __init nx_set_ct(struct nx_coproc *coproc, const char *priority,
+				int high, int normal)
+{
+	if (!strcmp(priority, "High"))
+		coproc->ct = high;
+	else if (!strcmp(priority, "Normal"))
+		coproc->ct = normal;
+	else {
+		pr_err("Invalid RxFIFO priority value\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
-					int vasid, int *ct)
+					int vasid, int type, int *ct)
 {
 	struct vas_window *rxwin = NULL;
 	struct vas_rx_win_attr rxattr;
-	struct nx842_coproc *coproc;
 	u32 lpid, pid, tid, fifo_size;
+	struct nx_coproc *coproc;
 	u64 rx_fifo;
 	const char *priority;
 	int ret;
@@ -794,15 +816,12 @@ static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
 	if (!coproc)
 		return -ENOMEM;
 
-	if (!strcmp(priority, "High"))
-		coproc->ct = VAS_COP_TYPE_842_HIPRI;
-	else if (!strcmp(priority, "Normal"))
-		coproc->ct = VAS_COP_TYPE_842;
-	else {
-		pr_err("Invalid RxFIFO priority value\n");
-		ret =  -EINVAL;
+	if (type == NX_CT_842)
+		ret = nx_set_ct(coproc, priority, VAS_COP_TYPE_842_HIPRI,
+			VAS_COP_TYPE_842);
+
+	if (ret)
 		goto err_out;
-	}
 
 	vas_init_rx_win_attr(&rxattr, coproc->ct);
 	rxattr.rx_fifo = (void *)rx_fifo;
@@ -830,7 +849,7 @@ static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
 
 	coproc->vas.rxwin = rxwin;
 	coproc->vas.id = vasid;
-	nx842_add_coprocs_list(coproc, chip_id);
+	nx_add_coprocs_list(coproc, chip_id);
 
 	/*
 	 * (lpid, pid, tid) combination has to be unique for each
@@ -848,13 +867,43 @@ static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
 	return ret;
 }
 
+static int __init nx_coproc_init(int chip_id, int ct_842)
+{
+	int ret = 0;
 
-static int __init nx842_powernv_probe_vas(struct device_node *pn)
+	if (opal_check_token(OPAL_NX_COPROC_INIT)) {
+		ret = opal_nx_coproc_init(chip_id, ct_842);
+		if (ret) {
+			ret = opal_error_code(ret);
+			pr_err("Failed to initialize NX for chip(%d): %d\n",
+				chip_id, ret);
+		}
+	} else
+		pr_warn("Firmware doesn't support NX initialization\n");
+
+	return ret;
+}
+
+static int __init find_nx_device_tree(struct device_node *dn, int chip_id,
+					int vasid, int type, char *devname,
+					int *ct)
+{
+	int ret = 0;
+
+	if (of_device_is_compatible(dn, devname)) {
+		ret  = vas_cfg_coproc_info(dn, chip_id, vasid, type, ct);
+		if (ret)
+			of_node_put(dn);
+	}
+
+	return ret;
+}
+
+static int __init nx_powernv_probe_vas(struct device_node *pn)
 {
-	struct device_node *dn;
 	int chip_id, vasid, ret = 0;
-	int nx_fifo_found = 0;
-	int uninitialized_var(ct);
+	struct device_node *dn;
+	int ct_842 = 0;
 
 	chip_id = of_get_ibm_chip_id(pn);
 	if (chip_id < 0) {
@@ -869,17 +918,13 @@ static int __init nx842_powernv_probe_vas(struct device_node *pn)
 	}
 
 	for_each_child_of_node(pn, dn) {
-		if (of_device_is_compatible(dn, "ibm,p9-nx-842")) {
-			ret = vas_cfg_coproc_info(dn, chip_id, vasid, &ct);
-			if (ret) {
-				of_node_put(dn);
-				return ret;
-			}
-			nx_fifo_found++;
-		}
+		ret = find_nx_device_tree(dn, chip_id, vasid, NX_CT_842,
+					"ibm,p9-nx-842", &ct_842);
+		if (ret)
+			return ret;
 	}
 
-	if (!nx_fifo_found) {
+	if (!ct_842) {
 		pr_err("NX842 FIFO nodes are missing\n");
 		return -EINVAL;
 	}
@@ -887,22 +932,14 @@ static int __init nx842_powernv_probe_vas(struct device_node *pn)
 	/*
 	 * Initialize NX instance for both high and normal priority FIFOs.
 	 */
-	if (opal_check_token(OPAL_NX_COPROC_INIT)) {
-		ret = opal_nx_coproc_init(chip_id, ct);
-		if (ret) {
-			pr_err("Failed to initialize NX for chip(%d): %d\n",
-				chip_id, ret);
-			ret = opal_error_code(ret);
-		}
-	} else
-		pr_warn("Firmware doesn't support NX initialization\n");
+	ret = nx_coproc_init(chip_id, ct_842);
 
 	return ret;
 }
 
 static int __init nx842_powernv_probe(struct device_node *dn)
 {
-	struct nx842_coproc *coproc;
+	struct nx_coproc *coproc;
 	unsigned int ct, ci;
 	int chip_id;
 
@@ -928,7 +965,7 @@ static int __init nx842_powernv_probe(struct device_node *dn)
 
 	coproc->ct = ct;
 	coproc->ci = ci;
-	nx842_add_coprocs_list(coproc, chip_id);
+	nx_add_coprocs_list(coproc, chip_id);
 
 	pr_info("coprocessor found on chip %d, CT %d CI %d\n", chip_id, ct, ci);
 
@@ -941,9 +978,9 @@ static int __init nx842_powernv_probe(struct device_node *dn)
 	return 0;
 }
 
-static void nx842_delete_coprocs(void)
+static void nx_delete_coprocs(void)
 {
-	struct nx842_coproc *coproc, *n;
+	struct nx_coproc *coproc, *n;
 	struct vas_window *txwin;
 	int i;
 
@@ -955,10 +992,10 @@ static void nx842_delete_coprocs(void)
 		if (txwin)
 			vas_win_close(txwin);
 
-		per_cpu(cpu_txwin, i) = 0;
+		per_cpu(cpu_txwin, i) = NULL;
 	}
 
-	list_for_each_entry_safe(coproc, n, &nx842_coprocs, list) {
+	list_for_each_entry_safe(coproc, n, &nx_coprocs, list) {
 		if (coproc->vas.rxwin)
 			vas_win_close(coproc->vas.rxwin);
 
@@ -1002,7 +1039,7 @@ static int nx842_powernv_crypto_init(struct crypto_tfm *tfm)
 	.coa_decompress		= nx842_crypto_decompress } }
 };
 
-static __init int nx842_powernv_init(void)
+static __init int nx_compress_powernv_init(void)
 {
 	struct device_node *dn;
 	int ret;
@@ -1017,15 +1054,15 @@ static __init int nx842_powernv_init(void)
 	BUILD_BUG_ON(DDE_BUFFER_SIZE_MULT % DDE_BUFFER_LAST_MULT);
 
 	for_each_compatible_node(dn, NULL, "ibm,power9-nx") {
-		ret = nx842_powernv_probe_vas(dn);
+		ret = nx_powernv_probe_vas(dn);
 		if (ret) {
-			nx842_delete_coprocs();
+			nx_delete_coprocs();
 			of_node_put(dn);
 			return ret;
 		}
 	}
 
-	if (list_empty(&nx842_coprocs)) {
+	if (list_empty(&nx_coprocs)) {
 		for_each_compatible_node(dn, NULL, "ibm,power-nx")
 			nx842_powernv_probe(dn);
 
@@ -1034,9 +1071,13 @@ static __init int nx842_powernv_init(void)
 
 		nx842_powernv_exec = nx842_exec_icswx;
 	} else {
-		ret = nx842_open_percpu_txwins();
+		/*
+		 * GZIP is not supported in kernel right now.
+		 * So open tx windows only for 842.
+		 */
+		ret = nx_open_percpu_txwins();
 		if (ret) {
-			nx842_delete_coprocs();
+			nx_delete_coprocs();
 			return ret;
 		}
 
@@ -1045,18 +1086,18 @@ static __init int nx842_powernv_init(void)
 
 	ret = crypto_register_alg(&nx842_powernv_alg);
 	if (ret) {
-		nx842_delete_coprocs();
+		nx_delete_coprocs();
 		return ret;
 	}
 
 	return 0;
 }
-module_init(nx842_powernv_init);
+module_init(nx_compress_powernv_init);
 
-static void __exit nx842_powernv_exit(void)
+static void __exit nx_compress_powernv_exit(void)
 {
 	crypto_unregister_alg(&nx842_powernv_alg);
 
-	nx842_delete_coprocs();
+	nx_delete_coprocs();
 }
-module_exit(nx842_powernv_exit);
+module_exit(nx_compress_powernv_exit);
-- 
1.8.3.1

[PATCH v3 7/9] crypto/nx: Enable and setup GZIP compresstion type

[Haren Myneni]

Changes to probe GZIP device-tree nodes, open RX windows and setup
GZIP compression type. No plans to provide GZIP usage in kernel right
now, but this patch enables GZIP for user space usage.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 drivers/crypto/nx/nx-common-powernv.c | 43 ++++++++++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 6 deletions(-)

diff --git a/drivers/crypto/nx/nx-common-powernv.c b/drivers/crypto/nx/nx-common-powernv.c
index 82dfa60..f570691 100644
--- a/drivers/crypto/nx/nx-common-powernv.c
+++ b/drivers/crypto/nx/nx-common-powernv.c
@@ -65,6 +65,7 @@ struct nx_coproc {
  * Using same values as in skiboot or coprocessor type representing
  * in NX workbook.
  */
+#define NX_CT_GZIP	(2)	/* on P9 and later */
 #define NX_CT_842	(3)
 
 static int (*nx842_powernv_exec)(const unsigned char *in,
@@ -819,6 +820,9 @@ static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
 	if (type == NX_CT_842)
 		ret = nx_set_ct(coproc, priority, VAS_COP_TYPE_842_HIPRI,
 			VAS_COP_TYPE_842);
+	else if (type == NX_CT_GZIP)
+		ret = nx_set_ct(coproc, priority, VAS_COP_TYPE_GZIP_HIPRI,
+				VAS_COP_TYPE_GZIP);
 
 	if (ret)
 		goto err_out;
@@ -867,12 +871,16 @@ static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
 	return ret;
 }
 
-static int __init nx_coproc_init(int chip_id, int ct_842)
+static int __init nx_coproc_init(int chip_id, int ct_842, int ct_gzip)
 {
 	int ret = 0;
 
 	if (opal_check_token(OPAL_NX_COPROC_INIT)) {
 		ret = opal_nx_coproc_init(chip_id, ct_842);
+
+		if (!ret)
+			ret = opal_nx_coproc_init(chip_id, ct_gzip);
+
 		if (ret) {
 			ret = opal_error_code(ret);
 			pr_err("Failed to initialize NX for chip(%d): %d\n",
@@ -902,8 +910,8 @@ static int __init find_nx_device_tree(struct device_node *dn, int chip_id,
 static int __init nx_powernv_probe_vas(struct device_node *pn)
 {
 	int chip_id, vasid, ret = 0;
+	int ct_842 = 0, ct_gzip = 0;
 	struct device_node *dn;
-	int ct_842 = 0;
 
 	chip_id = of_get_ibm_chip_id(pn);
 	if (chip_id < 0) {
@@ -920,19 +928,24 @@ static int __init nx_powernv_probe_vas(struct device_node *pn)
 	for_each_child_of_node(pn, dn) {
 		ret = find_nx_device_tree(dn, chip_id, vasid, NX_CT_842,
 					"ibm,p9-nx-842", &ct_842);
+
+		if (!ret)
+			ret = find_nx_device_tree(dn, chip_id, vasid,
+				NX_CT_GZIP, "ibm,p9-nx-gzip", &ct_gzip);
+
 		if (ret)
 			return ret;
 	}
 
-	if (!ct_842) {
-		pr_err("NX842 FIFO nodes are missing\n");
+	if (!ct_842 || !ct_gzip) {
+		pr_err("NX FIFO nodes are missing\n");
 		return -EINVAL;
 	}
 
 	/*
 	 * Initialize NX instance for both high and normal priority FIFOs.
 	 */
-	ret = nx_coproc_init(chip_id, ct_842);
+	ret = nx_coproc_init(chip_id, ct_842, ct_gzip);
 
 	return ret;
 }
@@ -1072,10 +1085,19 @@ static __init int nx_compress_powernv_init(void)
 		nx842_powernv_exec = nx842_exec_icswx;
 	} else {
 		/*
+		 * Register VAS user space API for NX GZIP so
+		 * that user space can use GZIP engine.
+		 * 842 compression is supported only in kernel.
+		 */
+		ret = vas_register_coproc_api(THIS_MODULE);
+
+		/*
 		 * GZIP is not supported in kernel right now.
 		 * So open tx windows only for 842.
 		 */
-		ret = nx_open_percpu_txwins();
+		if (!ret)
+			ret = nx_open_percpu_txwins();
+
 		if (ret) {
 			nx_delete_coprocs();
 			return ret;
@@ -1096,6 +1118,15 @@ static __init int nx_compress_powernv_init(void)
 
 static void __exit nx_compress_powernv_exit(void)
 {
+	/*
+	 * GZIP engine is supported only in power9 or later and nx842_ct
+	 * is used on power8 (icswx).
+	 * VAS API for NX GZIP is registered during init for user space
+	 * use. So delete this API use for GZIP engine.
+	 */
+	if (!nx842_ct)
+		vas_unregister_coproc_api();
+
 	crypto_unregister_alg(&nx842_powernv_alg);
 
 	nx_delete_coprocs();
-- 
1.8.3.1

[PATCH v3 8/9] crypto/nx: Remove 'pid' in vas_tx_win_attr struct

[Haren Myneni]

When window is opened, pid reference is taken for user space
windows. Not needed for kernel windows. So remove 'pid' in
vas_tx_win_attr struct.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 arch/powerpc/include/asm/vas.h        | 1 -
 drivers/crypto/nx/nx-common-powernv.c | 1 -
 2 files changed, 2 deletions(-)

diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index e064953..994db6f 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h
@@ -86,7 +86,6 @@ struct vas_tx_win_attr {
 	int wcreds_max;
 	int lpid;
 	int pidr;		/* hardware PID (from SPRN_PID) */
-	int pid;		/* linux process id */
 	int pswid;
 	int rsvd_txbuf_count;
 	int tc_mode;
diff --git a/drivers/crypto/nx/nx-common-powernv.c b/drivers/crypto/nx/nx-common-powernv.c
index f570691..38333e4 100644
--- a/drivers/crypto/nx/nx-common-powernv.c
+++ b/drivers/crypto/nx/nx-common-powernv.c
@@ -692,7 +692,6 @@ static struct vas_window *nx_alloc_txwin(struct nx_coproc *coproc)
 	 */
 	vas_init_tx_win_attr(&txattr, coproc->ct);
 	txattr.lpid = 0;	/* lpid is 0 for kernel requests */
-	txattr.pid = 0;		/* pid is 0 for kernel requests */
 
 	/*
 	 * Open a VAS send window which is used to send request to NX.
-- 
1.8.3.1

[PATCH v3 9/9] Documentation/powerpc: VAS API

[Haren Myneni]

Power9 introduced Virtual Accelerator Switchboard (VAS) which allows
userspace to communicate with Nest Accelerator (NX) directly. But
kernel has to establish channel to NX for userspace. This document
describes user space API that application can use to establish
communication channel.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 Documentation/powerpc/index.rst   |   1 +
 Documentation/powerpc/vas-api.rst | 246 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 247 insertions(+)
 create mode 100644 Documentation/powerpc/vas-api.rst

diff --git a/Documentation/powerpc/index.rst b/Documentation/powerpc/index.rst
index 0d45f0f..afe2d5e 100644
--- a/Documentation/powerpc/index.rst
+++ b/Documentation/powerpc/index.rst
@@ -30,6 +30,7 @@ powerpc
     syscall64-abi
     transactional_memory
     ultravisor
+    vas-api
 
 .. only::  subproject and html
 
diff --git a/Documentation/powerpc/vas-api.rst b/Documentation/powerpc/vas-api.rst
new file mode 100644
index 0000000..13ce4e7
--- /dev/null
+++ b/Documentation/powerpc/vas-api.rst
@@ -0,0 +1,246 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. _VAS-API:
+
+===================================================
+Virtual Accelerator Switchboard (VAS) userspace API
+===================================================
+
+Introduction
+============
+
+Power9 processor introduced Virtual Accelerator Switchboard (VAS) which
+allows both userspace and kernel communicate to co-processor
+(hardware accelerator) referred to as the Nest Accelerator (NX). The NX
+unit comprises of one or more hardware engines or co-processor types
+such as 842 compression, GZIP compression and encryption. On power9,
+userspace applications will have access to only GZIP Compression engine
+which supports ZLIB and GZIP compression algorithms in the hardware.
+
+To communicate with NX, kernel has to establish a channel or window and
+then requests can be submitted directly without kernel involvement.
+Requests to the GZIP engine must be formatted as a co-processor Request
+Block (CRB) and these CRBs must be submitted to the NX using COPY/PASTE
+instructions to paste the CRB to hardware address that is associated with
+the engine's request queue.
+
+The GZIP engine provides two priority levels of requests: Normal and
+High. Only Normal requests are supported from userspace right now.
+
+This document explains userspace API that is used to interact with
+kernel to setup channel / window which can be used to send compression
+requests directly to NX accelerator.
+
+
+Overview
+========
+
+Application access to the GZIP engine is provided through
+/dev/crypto/nx-gzip device node implemented by the VAS/NX device driver.
+An application must open the /dev/crypto/nx-gzip device to obtain a file
+descriptor (fd). Then should issue VAS_TX_WIN_OPEN ioctl with this fd to
+establish connection to the engine. It means send window is opened on GZIP
+engine for this process. Once a connection is established, the application
+should use the mmap() system call to map the hardware address of engine's
+request queue into the application's virtual address space.
+
+The application can then submit one or more requests to the the engine by
+using copy/paste instructions and pasting the CRBs to the virtual address
+(aka paste_address) returned by mmap(). User space can close the
+established connection or send window by closing the file descriptior
+(close(fd)) or upon the process exit.
+
+Note that applications can send several requests with the same window or
+can establish multiple windows, but one window for each file descriptor.
+
+Following sections provide additional details and references about the
+individual steps.
+
+NX-GZIP Device Node
+===================
+
+There is one /dev/crypto/nx-gzip node in the system and it provides
+access to all GZIP engines in the system. The only valid operations on
+/dev/crypto/nx-gzip are:
+
+	* open() the device for read and write.
+	* issue VAS_TX_WIN_OPEN ioctl
+	* mmap() the engine's request queue into application's virtual
+	  address space (i.e. get a paste_address for the co-processor
+	  engine).
+	* close the device node.
+
+Other file operations on this device node are undefined.
+
+Note that the copy and paste operations go directly to the hardware and
+do not go through this device. Refer COPY/PASTE document for more
+details.
+
+Although a system may have several instances of the NX co-processor
+engines (typically, one per P9 chip) there is just one
+/dev/crypto/nx-gzip device node in the system. When the nx-gzip device
+node is opened, Kernel opens send window on a suitable instance of NX
+accelerator. It finds CPU on which the user process is executing and
+determine the NX instance for the corresponding chip on which this CPU
+belongs.
+
+Applications may chose a specific instance of the NX co-processor using
+the vas_id field in the VAS_TX_WIN_OPEN ioctl as detailed below.
+
+A userspace library libnxz is available here but still in development:
+	 https://github.com/abalib/power-gzip
+
+Applications that use inflate / deflate calls can link with libnxz
+instead of libz and use NX GZIP compression without any modification.
+
+Open /dev/crypto/nx-gzip
+========================
+
+The nx-gzip device should be opened for read and write. No special
+privileges are needed to open the device. Each window coreesponds to one
+file descriptor. So if the userspace process needs multiple windows,
+several open calls have to be issued.
+
+See open(2) system call man pages for other details such as return values,
+error codes and restrictions.
+codes and restrictions.
+
+VAS_TX_WIN_OPEN ioctl
+=====================
+
+Applications should use the VAS_TX_WIN_OPEN ioctl as follows to establish
+a connection with NX co-processor engine:
+
+	::
+		struct vas_tx_win_open_attr {
+			__u32   version;
+			__s16   vas_id; /* specific instance of vas or -1
+						for default */
+			__u16   reserved1;
+			__u64   flags;	/* For future use */
+			__u64   reserved2[6];
+		};
+
+	version: The version field must be currently set to 1.
+	vas_id: If '-1' is passed, kernel will make a best-effort attempt
+		to assign an optimal instance of NX for the process. To
+		select the specific VAS instance, refer
+		"Discovery of available VAS engines" section below.
+
+	flags, reserved1 and reserved2[6] fields are for future extension
+	and must be set to 0.
+
+	The attributes attr for the VAS_TX_WIN_OPEN ioctl are defined as
+	follows:
+		#define VAS_MAGIC 'v'
+		#define VAS_TX_WIN_OPEN _IOW(VAS_MAGIC, 1,
+						struct vas_tx_win_open_attr)
+
+		struct vas_tx_win_open_attr attr;
+		rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr);
+
+	The VAS_TX_WIN_OPEN ioctl returns 0 on success. On errors, it
+	returns -1 and sets the errno variable to indicate the error.
+
+	Error conditions:
+		EINVAL	fd does not refer to a valid VAS device.
+		EINVAL	Invalid vas ID
+		EINVAL	version is not set with proper value
+		EEXIST	Window is already opened for the given fd
+		ENOMEM	Memory is not available to allocate window
+		ENOSPC	System has too many active windows (connections)
+			opened
+		EINVAL	reserved fields are not set to 0.
+
+	See the ioctl(2) man page for more details, error codes and
+	restrictions.
+
+mmap() NX-GZIP device
+=====================
+
+The mmap() system call for a NX-GZIP device fd returns a paste_address
+that the application can use to copy/paste its CRB to the hardware engines.
+	::
+
+		paste_addr = mmap(addr, size, prot, flags, fd, offset);
+
+	Only restrictions on mmap for a NX-GZIP device fd are:
+		* size should be 4K page size
+		* offset parameter should be 0ULL
+
+	Refer to mmap(2) man page for additional details/restrictions.
+	In addition to the error conditions listed on the mmap(2) man
+	page, can also fail with one of the following error codes:
+
+		EINVAL	fd is not associated with an open window
+			(i.e mmap() does not follow a successful call
+			to the VAS_TX_WIN_OPEN ioctl).
+		EINVAL	offset field is not 0ULL.
+
+Discovery of available VAS engines
+==================================
+
+Each available VAS instance in the system will have a device tree node
+like /proc/device-tree/vas@* or /proc/device-tree/xscom@*/vas@*.
+Determine the chip or VAS instance and use the corresponding ibm,vas-id
+property value in this node to select specific VAS instance.
+
+Copy/Paste operations
+=====================
+
+Applications should use the copy and paste instructions defined in the RFC
+to copy/paste the CRB.
+
+CRB Specification and use NX
+============================
+
+Applications should format requests to the co-processor using the
+co-processor Request Block (CRBs). Refer NX workbook for the format of
+CRB and use NX from userspace such as sending requests and checking
+request status.
+
+Simple example
+==============
+
+	::
+		int use_nx_gzip()
+		{
+			int rc, fd;
+			void *addr;
+			struct vas_setup_attr txattr;
+
+			fd = open("/dev/crypto/nx-gzip", O_RDWR);
+			if (fd < 0) {
+				fprintf(stderr, "open nx-gzip failed\n");
+				return -1;
+			}
+			memset(&txattr, 0, sizeof(txattr));
+			txattr.version = 1;
+			txattr.vas_id = -1
+			rc = ioctl(fd, VAS_TX_WIN_OPEN,
+					(unsigned long)&txattr);
+			if (rc < 0) {
+				fprintf(stderr, "ioctl() n %d, error %d\n",
+						rc, errno);
+				return rc;
+			}
+			addr = mmap(NULL, 4096, PROT_READ|PROT_WRITE,
+					MAP_SHARED, fd, 0ULL);
+			if (addr == MAP_FAILED) {
+				fprintf(stderr, "mmap() failed, errno %d\n",
+						errno);
+				return -errno;
+			}
+			do {
+				//Format CRB request with compression or
+				//uncompression
+				// Refer tests for vas_copy/vas_paste
+				vas_copy((&crb, 0, 1);
+				vas_paste(addr, 0, 1);
+				// Poll on csb.flags with timeout
+				// csb address is listed in CRB
+			} while (true)
+			close(fd) or window can be closed upon process exit
+		}
+
+	Refer https://github.com/abalib/power-gzip for tests or more
+	use cases.
-- 
1.8.3.1

Re: [PATCH v3 0/9] crypto/nx: Enable GZIP engine and provide userpace API

[Daniel Axtens]

Hi Haren,

If I understand correctly, to test these, I need to apply both this
series and your VAS userspace page fault handling series - is that
right?

Kind regards,
Daniel

> Power9 processor supports Virtual Accelerator Switchboard (VAS) which
> allows kernel and userspace to send compression requests to Nest
> Accelerator (NX) directly. The NX unit comprises of 2 842 compression
> engines and 1 GZIP engine. Linux kernel already has 842 compression
> support on kernel. This patch series adds GZIP compression support
> from user space. The GZIP Compression engine implements the ZLIB and
> GZIP compression algorithms. No plans of adding NX-GZIP compression
> support in kernel right now.
>
> Applications can send requests to NX directly with COPY/PASTE
> instructions. But kernel has to establish channel / window on NX-GZIP
> device for the userspace. So userspace access to the GZIP engine is
> provided through /dev/crypto/nx-gzip device with several operations.
>
> An application must open the this device to obtain a file descriptor (fd).
> Using the fd, application should issue the VAS_TX_WIN_OPEN ioctl to
> establish a connection to the engine. Once window is opened, should use
> mmap() system call to map the hardware address of engine's request queue
> into the application's virtual address space. Then user space forms the
> request as co-processor Request Block (CRB) and paste this CRB on the
> mapped HW address using COPY/PASTE instructions. Application can poll
> on status flags (part of CRB) with timeout for request completion.
>
> For VAS_TX_WIN_OPEN ioctl, if user space passes vas_id = -1 (struct
> vas_tx_win_open_attr), kernel determines the VAS instance on the
> corresponding chip based on the CPU on which the process is executing.
> Otherwise, the specified VAS instance is used if application passes the
> proper VAS instance (vas_id listed in /proc/device-tree/vas@*/ibm,vas_id).
>
> Process can open multiple windows with different FDs or can send several
> requests to NX on the same window at the same time.
>
> A userspace library libnxz is available:
>         https://github.com/abalib/power-gzip
>
> Applications that use inflate/deflate calls can link with libNXz and use
> NX GZIP compression without any modification.
>
> Tested the available 842 compression on power8 and power9 system to make
> sure no regression and tested GZIP compression on power9 with tests
> available in the above link.
>
> Thanks to Bulent Abali for nxz library and tests development.
>
> Changelog:
> V2:
>   - Move user space API code to powerpc as suggested. Also this API
>     can be extended to any other coprocessor type that VAS can support
>     in future. Example: Fast thread wakeup feature from VAS
>   - Rebased to 5.6-rc3
>
> V3:
>   - Fix sparse warnings (patches 3&6)
>
> Haren Myneni (9):
>   powerpc/vas: Initialize window attributes for GZIP coprocessor type
>   powerpc/vas: Define VAS_TX_WIN_OPEN ioctl API
>   powerpc/vas: Add VAS user space API
>   crypto/nx: Initialize coproc entry with kzalloc
>   crypto/nx: Rename nx-842-powernv file name to nx-common-powernv
>   crypto/NX: Make enable code generic to add new GZIP compression type
>   crypto/nx: Enable and setup GZIP compresstion type
>   crypto/nx: Remove 'pid' in vas_tx_win_attr struct
>   Documentation/powerpc: VAS API
>
>  Documentation/powerpc/index.rst                    |    1 +
>  Documentation/powerpc/vas-api.rst                  |  246 +++++
>  Documentation/userspace-api/ioctl/ioctl-number.rst |    1 +
>  arch/powerpc/include/asm/vas.h                     |   12 +-
>  arch/powerpc/include/uapi/asm/vas-api.h            |   22 +
>  arch/powerpc/platforms/powernv/Makefile            |    2 +-
>  arch/powerpc/platforms/powernv/vas-api.c           |  290 +++++
>  arch/powerpc/platforms/powernv/vas-window.c        |   23 +-
>  arch/powerpc/platforms/powernv/vas.h               |    2 +
>  drivers/crypto/nx/Makefile                         |    2 +-
>  drivers/crypto/nx/nx-842-powernv.c                 | 1062 ------------------
>  drivers/crypto/nx/nx-common-powernv.c              | 1133 ++++++++++++++++++++
>  12 files changed, 1723 insertions(+), 1073 deletions(-)
>  create mode 100644 Documentation/powerpc/vas-api.rst
>  create mode 100644 arch/powerpc/include/uapi/asm/vas-api.h
>  create mode 100644 arch/powerpc/platforms/powernv/vas-api.c
>  delete mode 100644 drivers/crypto/nx/nx-842-powernv.c
>  create mode 100644 drivers/crypto/nx/nx-common-powernv.c
>
> -- 
> 1.8.3.1

Re: [PATCH v3 0/9] crypto/nx: Enable GZIP engine and provide userpace API

[Haren Myneni]

On Tue, 2020-03-17 at 00:04 +1100, Daniel Axtens wrote:
> Hi Haren,
> 
> If I understand correctly, to test these, I need to apply both this
> series and your VAS userspace page fault handling series - is that
> right?

Daniel, 

Yes, This patch series enables GZIP engine and provides user space API.
Whereas VAS fault handling series process faults if NX sees fault on
request buffer.  

selftest -
https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-March/206035.html

or https://github.com/abalib/power-gzip/tree/develop/selftest

More tests are available - https://github.com/abalib/power-gzip

libnxz - https://github.com/libnxz/power-gzip  

Thanks
Haren

> 
> Kind regards,
> Daniel
> 
> > Power9 processor supports Virtual Accelerator Switchboard (VAS) which
> > allows kernel and userspace to send compression requests to Nest
> > Accelerator (NX) directly. The NX unit comprises of 2 842 compression
> > engines and 1 GZIP engine. Linux kernel already has 842 compression
> > support on kernel. This patch series adds GZIP compression support
> > from user space. The GZIP Compression engine implements the ZLIB and
> > GZIP compression algorithms. No plans of adding NX-GZIP compression
> > support in kernel right now.
> >
> > Applications can send requests to NX directly with COPY/PASTE
> > instructions. But kernel has to establish channel / window on NX-GZIP
> > device for the userspace. So userspace access to the GZIP engine is
> > provided through /dev/crypto/nx-gzip device with several operations.
> >
> > An application must open the this device to obtain a file descriptor (fd).
> > Using the fd, application should issue the VAS_TX_WIN_OPEN ioctl to
> > establish a connection to the engine. Once window is opened, should use
> > mmap() system call to map the hardware address of engine's request queue
> > into the application's virtual address space. Then user space forms the
> > request as co-processor Request Block (CRB) and paste this CRB on the
> > mapped HW address using COPY/PASTE instructions. Application can poll
> > on status flags (part of CRB) with timeout for request completion.
> >
> > For VAS_TX_WIN_OPEN ioctl, if user space passes vas_id = -1 (struct
> > vas_tx_win_open_attr), kernel determines the VAS instance on the
> > corresponding chip based on the CPU on which the process is executing.
> > Otherwise, the specified VAS instance is used if application passes the
> > proper VAS instance (vas_id listed in /proc/device-tree/vas@*/ibm,vas_id).
> >
> > Process can open multiple windows with different FDs or can send several
> > requests to NX on the same window at the same time.
> >
> > A userspace library libnxz is available:
> >         https://github.com/abalib/power-gzip
> >
> > Applications that use inflate/deflate calls can link with libNXz and use
> > NX GZIP compression without any modification.
> >
> > Tested the available 842 compression on power8 and power9 system to make
> > sure no regression and tested GZIP compression on power9 with tests
> > available in the above link.
> >
> > Thanks to Bulent Abali for nxz library and tests development.
> >
> > Changelog:
> > V2:
> >   - Move user space API code to powerpc as suggested. Also this API
> >     can be extended to any other coprocessor type that VAS can support
> >     in future. Example: Fast thread wakeup feature from VAS
> >   - Rebased to 5.6-rc3
> >
> > V3:
> >   - Fix sparse warnings (patches 3&6)
> >
> > Haren Myneni (9):
> >   powerpc/vas: Initialize window attributes for GZIP coprocessor type
> >   powerpc/vas: Define VAS_TX_WIN_OPEN ioctl API
> >   powerpc/vas: Add VAS user space API
> >   crypto/nx: Initialize coproc entry with kzalloc
> >   crypto/nx: Rename nx-842-powernv file name to nx-common-powernv
> >   crypto/NX: Make enable code generic to add new GZIP compression type
> >   crypto/nx: Enable and setup GZIP compresstion type
> >   crypto/nx: Remove 'pid' in vas_tx_win_attr struct
> >   Documentation/powerpc: VAS API
> >
> >  Documentation/powerpc/index.rst                    |    1 +
> >  Documentation/powerpc/vas-api.rst                  |  246 +++++
> >  Documentation/userspace-api/ioctl/ioctl-number.rst |    1 +
> >  arch/powerpc/include/asm/vas.h                     |   12 +-
> >  arch/powerpc/include/uapi/asm/vas-api.h            |   22 +
> >  arch/powerpc/platforms/powernv/Makefile            |    2 +-
> >  arch/powerpc/platforms/powernv/vas-api.c           |  290 +++++
> >  arch/powerpc/platforms/powernv/vas-window.c        |   23 +-
> >  arch/powerpc/platforms/powernv/vas.h               |    2 +
> >  drivers/crypto/nx/Makefile                         |    2 +-
> >  drivers/crypto/nx/nx-842-powernv.c                 | 1062 ------------------
> >  drivers/crypto/nx/nx-common-powernv.c              | 1133 ++++++++++++++++++++
> >  12 files changed, 1723 insertions(+), 1073 deletions(-)
> >  create mode 100644 Documentation/powerpc/vas-api.rst
> >  create mode 100644 arch/powerpc/include/uapi/asm/vas-api.h
> >  create mode 100644 arch/powerpc/platforms/powernv/vas-api.c
> >  delete mode 100644 drivers/crypto/nx/nx-842-powernv.c
> >  create mode 100644 drivers/crypto/nx/nx-common-powernv.c
> >
> > -- 
> > 1.8.3.1

Re: [PATCH v3 3/9] powerpc/vas: Add VAS user space API

[Daniel Axtens]

Haren Myneni <haren@linux.ibm.com> writes:

> On power9, userspace can send GZIP compression requests directly to NX
> once kernel establishes NX channel / window with VAS. This patch provides
> user space API which allows user space to establish channel using open
> VAS_TX_WIN_OPEN ioctl, mmap and close operations.
>
> Each window corresponds to file descriptor and application can open
> multiple windows. After the window is opened, VAS_TX_WIN_OPEN icoctl to
> open a window on specific VAS instance, mmap() system call to map
> the hardware address of engine's request queue into the application's
> virtual address space.
>
> Then the application can then submit one or more requests to the the
> engine by using the copy/paste instructions and pasting the CRBs to
> the virtual address (aka paste_address) returned by mmap().
>
> Only NX GZIP coprocessor type is supported right now and allow GZIP
> engine access via /dev/crypto/nx-gzip device node.
>
> Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
> Signed-off-by: Haren Myneni <haren@linux.ibm.com>
> ---
>  arch/powerpc/include/asm/vas.h              |  11 ++
>  arch/powerpc/platforms/powernv/Makefile     |   2 +-
>  arch/powerpc/platforms/powernv/vas-api.c    | 290 ++++++++++++++++++++++++++++
>  arch/powerpc/platforms/powernv/vas-window.c |   6 +-
>  arch/powerpc/platforms/powernv/vas.h        |   2 +
>  5 files changed, 307 insertions(+), 4 deletions(-)
>  create mode 100644 arch/powerpc/platforms/powernv/vas-api.c
>
> diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
> index f93e6b0..e064953 100644
> --- a/arch/powerpc/include/asm/vas.h
> +++ b/arch/powerpc/include/asm/vas.h
> @@ -163,4 +163,15 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
>   */
>  int vas_paste_crb(struct vas_window *win, int offset, bool re);
>  
> +/*
> + * Register / unregister coprocessor type to VAS API which will be exported
> + * to user space. Applications can use this API to open / close window
> + * which can be used to send / receive requests directly to cooprcessor.
> + *
> + * Only NX GZIP coprocessor type is supported now, but this API can be
> + * used for others in future.
> + */
> +int vas_register_coproc_api(struct module *mod);
> +void vas_unregister_coproc_api(void);
> +
>  #endif /* __ASM_POWERPC_VAS_H */
> diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
> index 395789f..fe3f0fb 100644
> --- a/arch/powerpc/platforms/powernv/Makefile
> +++ b/arch/powerpc/platforms/powernv/Makefile
> @@ -17,7 +17,7 @@ obj-$(CONFIG_MEMORY_FAILURE)	+= opal-memory-errors.o
>  obj-$(CONFIG_OPAL_PRD)	+= opal-prd.o
>  obj-$(CONFIG_PERF_EVENTS) += opal-imc.o
>  obj-$(CONFIG_PPC_MEMTRACE)	+= memtrace.o
> -obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o
> +obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o vas-api.o
>  obj-$(CONFIG_OCXL_BASE)	+= ocxl.o
>  obj-$(CONFIG_SCOM_DEBUGFS) += opal-xscom.o
>  obj-$(CONFIG_PPC_SECURE_BOOT) += opal-secvar.o
> diff --git a/arch/powerpc/platforms/powernv/vas-api.c b/arch/powerpc/platforms/powernv/vas-api.c
> new file mode 100644
> index 0000000..3473a4a
> --- /dev/null
> +++ b/arch/powerpc/platforms/powernv/vas-api.c
> @@ -0,0 +1,290 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * VAS user space API for its accelerators (Only NX-GZIP is supported now)
> + * Copyright (C) 2019 Haren Myneni, IBM Corp
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/cdev.h>
> +#include <linux/fs.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +#include <asm/vas.h>
> +#include <uapi/asm/vas-api.h>
> +#include "vas.h"
> +
> +/*
> + * The driver creates the device node that can be used as follows:
> + * For NX-GZIP
> + *
> + *	fd = open("/dev/crypto/nx-gzip", O_RDWR);
> + *	rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr);
> + *	paste_addr = mmap(NULL, PAGE_SIZE, prot, MAP_SHARED, fd, 0ULL).
> + *	vas_copy(&crb, 0, 1);
> + *	vas_paste(paste_addr, 0, 1);
> + *	close(fd) or exit process to close window.
> + *
> + * where "vas_copy" and "vas_paste" are defined in copy-paste.h.
> + * copy/paste returns to the user space directly. So refer NX hardware
> + * documententation for excat copy/paste usage and completion / error

s/excat/exact/

I'm still experimenting with this so I might have more comments later,
but I wanted to send this before I forgot or lost it :)

Daniel

> + * conditions.
> + */
> +
> +static char	*coproc_dev_name = "nx-gzip";
> +static atomic_t	coproc_instid = ATOMIC_INIT(0);
> +
> +/*
> + * Wrapper object for the nx-gzip device - there is just one instance of
> + * this node for the whole system.
> + */
> +static struct coproc_dev {
> +	struct cdev cdev;
> +	struct device *device;
> +	char *name;
> +	dev_t devt;
> +	struct class *class;
> +} coproc_device;
> +
> +/*
> + * One instance per open of a nx-gzip device. Each coproc_instance is
> + * associated with a VAS window after the caller issues
> + * VAS_GZIP_TX_WIN_OPEN ioctl.
> + */
> +struct coproc_instance {
> +	int id;
> +	struct vas_window *txwin;
> +};
> +
> +static char *coproc_devnode(struct device *dev, umode_t *mode)
> +{
> +	return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev));
> +}
> +
> +static int coproc_open(struct inode *inode, struct file *fp)
> +{
> +	struct coproc_instance *instance;
> +
> +	instance = kzalloc(sizeof(*instance), GFP_KERNEL);
> +	if (!instance)
> +		return -ENOMEM;
> +
> +	instance->id = atomic_inc_return(&coproc_instid);
> +
> +	fp->private_data = instance;
> +	return 0;
> +}
> +
> +static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
> +{
> +	int rc, vasid;
> +	struct vas_tx_win_attr txattr;
> +	struct vas_tx_win_open_attr uattr;
> +	void __user *uptr = (void __user *)arg;
> +	struct vas_window *txwin;
> +	struct coproc_instance *nxti = fp->private_data;
> +
> +	if (!nxti)
> +		return -EINVAL;
> +
> +	/*
> +	 * One window for file descriptor
> +	 */
> +	if (nxti->txwin)
> +		return -EEXIST;
> +
> +	rc = copy_from_user(&uattr, uptr, sizeof(uattr));
> +	if (rc) {
> +		pr_err("%s(): copy_from_user() returns %d\n", __func__, rc);
> +		return -EFAULT;
> +	}
> +
> +	if (uattr.version != 1) {
> +		pr_err("Invalid version\n");
> +		return -EINVAL;
> +	}
> +
> +	vasid = uattr.vas_id;
> +
> +	memset(&txattr, 0, sizeof(struct vas_tx_win_attr));
> +	vas_init_tx_win_attr(&txattr, VAS_COP_TYPE_GZIP);
> +
> +	txattr.lpid = mfspr(SPRN_LPID);
> +	txattr.pidr = mfspr(SPRN_PID);
> +	txattr.user_win = true;
> +	txattr.rsvd_txbuf_count = false;
> +	txattr.pswid = false;
> +	/*
> +	 * txattr.wcreds_max is set to VAS_WCREDS_DEFAULT (1024) in
> +	 * vas-window.c, but can be changed specific to GZIP depends
> +	 * on user space need.
> +	 * If needed to set txattr.wcreds_max here.
> +	 */
> +
> +	pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
> +				mfspr(SPRN_PID));
> +
> +	txwin = vas_tx_win_open(vasid, VAS_COP_TYPE_GZIP, &txattr);
> +	if (IS_ERR(txwin)) {
> +		pr_err("%s() vas_tx_win_open() failed, %ld\n", __func__,
> +					PTR_ERR(txwin));
> +		return PTR_ERR(txwin);
> +	}
> +
> +	nxti->txwin = txwin;
> +
> +	return 0;
> +}
> +
> +static int coproc_release(struct inode *inode, struct file *fp)
> +{
> +	struct coproc_instance *instance;
> +
> +	instance = fp->private_data;
> +
> +	if (instance && instance->txwin) {
> +		vas_win_close(instance->txwin);
> +		instance->txwin = NULL;
> +	}
> +
> +	/*
> +	 * We don't know here if user has other receive windows
> +	 * open, so we can't really call clear_thread_tidr().
> +	 * So, once the process calls set_thread_tidr(), the
> +	 * TIDR value sticks around until process exits, resulting
> +	 * in an extra copy in restore_sprs().
> +	 */
> +
> +	kfree(instance);
> +	fp->private_data = NULL;
> +	atomic_dec(&coproc_instid);
> +
> +	return 0;
> +}
> +
> +static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
> +{
> +	int rc;
> +	pgprot_t prot;
> +	u64 paste_addr;
> +	unsigned long pfn;
> +	struct coproc_instance *instance = fp->private_data;
> +
> +	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
> +		pr_debug("%s(): size 0x%zx, PAGE_SIZE 0x%zx\n", __func__,
> +				(vma->vm_end - vma->vm_start), PAGE_SIZE);
> +		return -EINVAL;
> +	}
> +
> +	/* Ensure instance has an open send window */
> +	if (!instance->txwin) {
> +		pr_err("%s(): No send window open?\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	vas_win_paste_addr(instance->txwin, &paste_addr, NULL);
> +	pfn = paste_addr >> PAGE_SHIFT;
> +
> +	/* flags, page_prot from cxl_mmap(), except we want cachable */
> +	vma->vm_flags |= VM_IO | VM_PFNMAP;
> +	vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
> +
> +	prot = __pgprot(pgprot_val(vma->vm_page_prot) | _PAGE_DIRTY);
> +
> +	rc = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
> +			vma->vm_end - vma->vm_start, prot);
> +
> +	pr_devel("%s(): paste addr %llx at %lx, rc %d\n", __func__,
> +			paste_addr, vma->vm_start, rc);
> +
> +	return rc;
> +}
> +
> +static long coproc_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
> +{
> +	switch (cmd) {
> +	case VAS_TX_WIN_OPEN:
> +		return coproc_ioc_tx_win_open(fp, arg);
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static struct file_operations coproc_fops = {
> +	.open = coproc_open,
> +	.release = coproc_release,
> +	.mmap = coproc_mmap,
> +	.unlocked_ioctl = coproc_ioctl,
> +};
> +
> +/*
> + * Supporting only nx-gzip coprocessor type now, but this API code
> + * extended to other coprocessor types later.
> + */
> +int vas_register_coproc_api(struct module *mod)
> +{
> +	int rc = -EINVAL;
> +	dev_t devno;
> +
> +	rc = alloc_chrdev_region(&coproc_device.devt, 1, 1, "nx-gzip");
> +	if (rc) {
> +		pr_err("Unable to allocate coproc major number: %i\n", rc);
> +		return rc;
> +	}
> +
> +	pr_devel("NX-GZIP device allocated, dev [%i,%i]\n",
> +			MAJOR(coproc_device.devt), MINOR(coproc_device.devt));
> +
> +	coproc_device.class = class_create(mod, "nx-gzip");
> +	if (IS_ERR(coproc_device.class)) {
> +		rc = PTR_ERR(coproc_device.class);
> +		pr_err("Unable to create NX-GZIP class %d\n", rc);
> +		goto err_class;
> +	}
> +	coproc_device.class->devnode = coproc_devnode;
> +
> +	coproc_fops.owner = mod;
> +	cdev_init(&coproc_device.cdev, &coproc_fops);
> +
> +	devno = MKDEV(MAJOR(coproc_device.devt), 0);
> +	rc = cdev_add(&coproc_device.cdev, devno, 1);
> +	if (rc) {
> +		pr_err("cdev_add() failed %d\n", rc);
> +		goto err_cdev;
> +	}
> +
> +	coproc_device.device = device_create(coproc_device.class, NULL,
> +			devno, NULL, coproc_dev_name, MINOR(devno));
> +	if (IS_ERR(coproc_device.device)) {
> +		rc = PTR_ERR(coproc_device.device);
> +		pr_err("Unable to create coproc-%d %d\n", MINOR(devno), rc);
> +		goto err;
> +	}
> +
> +	pr_devel("%s: Added dev [%d,%d]\n", __func__, MAJOR(devno),
> +			MINOR(devno));
> +
> +	return 0;
> +
> +err:
> +	cdev_del(&coproc_device.cdev);
> +err_cdev:
> +	class_destroy(coproc_device.class);
> +err_class:
> +	unregister_chrdev_region(coproc_device.devt, 1);
> +	return rc;
> +}
> +EXPORT_SYMBOL_GPL(vas_register_coproc_api);
> +
> +void vas_unregister_coproc_api(void)
> +{
> +	dev_t devno;
> +
> +	cdev_del(&coproc_device.cdev);
> +	devno = MKDEV(MAJOR(coproc_device.devt), 0);
> +	device_destroy(coproc_device.class, devno);
> +
> +	class_destroy(coproc_device.class);
> +	unregister_chrdev_region(coproc_device.devt, 1);
> +}
> +EXPORT_SYMBOL_GPL(vas_unregister_coproc_api);
> diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
> index e9ab851..7484296 100644
> --- a/arch/powerpc/platforms/powernv/vas-window.c
> +++ b/arch/powerpc/platforms/powernv/vas-window.c
> @@ -26,7 +26,7 @@
>   * Compute the paste address region for the window @window using the
>   * ->paste_base_addr and ->paste_win_id_shift we got from device tree.
>   */
> -static void compute_paste_address(struct vas_window *window, u64 *addr, int *len)
> +void vas_win_paste_addr(struct vas_window *window, u64 *addr, int *len)
>  {
>  	int winid;
>  	u64 base, shift;
> @@ -80,7 +80,7 @@ static void *map_paste_region(struct vas_window *txwin)
>  		goto free_name;
>  
>  	txwin->paste_addr_name = name;
> -	compute_paste_address(txwin, &start, &len);
> +	vas_win_paste_addr(txwin, &start, &len);
>  
>  	if (!request_mem_region(start, len, name)) {
>  		pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
> @@ -138,7 +138,7 @@ static void unmap_paste_region(struct vas_window *window)
>  	u64 busaddr_start;
>  
>  	if (window->paste_kaddr) {
> -		compute_paste_address(window, &busaddr_start, &len);
> +		vas_win_paste_addr(window, &busaddr_start, &len);
>  		unmap_region(window->paste_kaddr, busaddr_start, len);
>  		window->paste_kaddr = NULL;
>  		kfree(window->paste_addr_name);
> diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
> index 8c39a7d..a10abed 100644
> --- a/arch/powerpc/platforms/powernv/vas.h
> +++ b/arch/powerpc/platforms/powernv/vas.h
> @@ -431,6 +431,8 @@ struct vas_winctx {
>  extern void vas_return_credit(struct vas_window *window, bool tx);
>  extern struct vas_window *vas_pswid_to_window(struct vas_instance *vinst,
>  						uint32_t pswid);
> +extern void vas_win_paste_addr(struct vas_window *window, u64 *addr,
> +					int *len);
>  
>  static inline int vas_window_pid(struct vas_window *window)
>  {
> -- 
> 1.8.3.1

Re: [PATCH v3 3/9] powerpc/vas: Add VAS user space API

[Daniel Axtens]

Haren Myneni <haren@linux.ibm.com> writes:

> On power9, userspace can send GZIP compression requests directly to NX
> once kernel establishes NX channel / window with VAS. This patch provides
> user space API which allows user space to establish channel using open
> VAS_TX_WIN_OPEN ioctl, mmap and close operations.
>
> Each window corresponds to file descriptor and application can open
> multiple windows. After the window is opened, VAS_TX_WIN_OPEN icoctl to
> open a window on specific VAS instance, mmap() system call to map
> the hardware address of engine's request queue into the application's
> virtual address space.
>
> Then the application can then submit one or more requests to the the
> engine by using the copy/paste instructions and pasting the CRBs to
> the virtual address (aka paste_address) returned by mmap().
>
> Only NX GZIP coprocessor type is supported right now and allow GZIP
> engine access via /dev/crypto/nx-gzip device node.
>
> Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
> Signed-off-by: Haren Myneni <haren@linux.ibm.com>
> ---
>  arch/powerpc/include/asm/vas.h              |  11 ++
>  arch/powerpc/platforms/powernv/Makefile     |   2 +-
>  arch/powerpc/platforms/powernv/vas-api.c    | 290 ++++++++++++++++++++++++++++
>  arch/powerpc/platforms/powernv/vas-window.c |   6 +-
>  arch/powerpc/platforms/powernv/vas.h        |   2 +
>  5 files changed, 307 insertions(+), 4 deletions(-)
>  create mode 100644 arch/powerpc/platforms/powernv/vas-api.c
>
> diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
> index f93e6b0..e064953 100644
> --- a/arch/powerpc/include/asm/vas.h
> +++ b/arch/powerpc/include/asm/vas.h
> @@ -163,4 +163,15 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
>   */
>  int vas_paste_crb(struct vas_window *win, int offset, bool re);
>  
> +/*
> + * Register / unregister coprocessor type to VAS API which will be exported
> + * to user space. Applications can use this API to open / close window
> + * which can be used to send / receive requests directly to cooprcessor.
> + *
> + * Only NX GZIP coprocessor type is supported now, but this API can be
> + * used for others in future.
> + */
> +int vas_register_coproc_api(struct module *mod);
> +void vas_unregister_coproc_api(void);
> +
>  #endif /* __ASM_POWERPC_VAS_H */
> diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
> index 395789f..fe3f0fb 100644
> --- a/arch/powerpc/platforms/powernv/Makefile
> +++ b/arch/powerpc/platforms/powernv/Makefile
> @@ -17,7 +17,7 @@ obj-$(CONFIG_MEMORY_FAILURE)	+= opal-memory-errors.o
>  obj-$(CONFIG_OPAL_PRD)	+= opal-prd.o
>  obj-$(CONFIG_PERF_EVENTS) += opal-imc.o
>  obj-$(CONFIG_PPC_MEMTRACE)	+= memtrace.o
> -obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o
> +obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o vas-api.o
>  obj-$(CONFIG_OCXL_BASE)	+= ocxl.o
>  obj-$(CONFIG_SCOM_DEBUGFS) += opal-xscom.o
>  obj-$(CONFIG_PPC_SECURE_BOOT) += opal-secvar.o
> diff --git a/arch/powerpc/platforms/powernv/vas-api.c b/arch/powerpc/platforms/powernv/vas-api.c
> new file mode 100644
> index 0000000..3473a4a
> --- /dev/null
> +++ b/arch/powerpc/platforms/powernv/vas-api.c
> @@ -0,0 +1,290 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * VAS user space API for its accelerators (Only NX-GZIP is supported now)
> + * Copyright (C) 2019 Haren Myneni, IBM Corp
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/cdev.h>
> +#include <linux/fs.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +#include <asm/vas.h>
> +#include <uapi/asm/vas-api.h>
> +#include "vas.h"
> +
> +/*
> + * The driver creates the device node that can be used as follows:
> + * For NX-GZIP
> + *
> + *	fd = open("/dev/crypto/nx-gzip", O_RDWR);
> + *	rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr);
> + *	paste_addr = mmap(NULL, PAGE_SIZE, prot, MAP_SHARED, fd, 0ULL).
> + *	vas_copy(&crb, 0, 1);
> + *	vas_paste(paste_addr, 0, 1);
> + *	close(fd) or exit process to close window.
> + *
> + * where "vas_copy" and "vas_paste" are defined in copy-paste.h.
> + * copy/paste returns to the user space directly. So refer NX hardware
> + * documententation for excat copy/paste usage and completion / error
> + * conditions.
> + */
> +
> +static char	*coproc_dev_name = "nx-gzip";
> +static atomic_t	coproc_instid = ATOMIC_INIT(0);
> +
> +/*
> + * Wrapper object for the nx-gzip device - there is just one instance of
> + * this node for the whole system.
> + */
> +static struct coproc_dev {
> +	struct cdev cdev;
> +	struct device *device;
> +	char *name;
> +	dev_t devt;
> +	struct class *class;
> +} coproc_device;
> +
> +/*
> + * One instance per open of a nx-gzip device. Each coproc_instance is
> + * associated with a VAS window after the caller issues
> + * VAS_GZIP_TX_WIN_OPEN ioctl.
> + */
> +struct coproc_instance {
> +	int id;
> +	struct vas_window *txwin;
> +};
> +
> +static char *coproc_devnode(struct device *dev, umode_t *mode)
> +{
> +	return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev));
> +}
> +
> +static int coproc_open(struct inode *inode, struct file *fp)
> +{
> +	struct coproc_instance *instance;
> +
> +	instance = kzalloc(sizeof(*instance), GFP_KERNEL);
> +	if (!instance)
> +		return -ENOMEM;
> +
> +	instance->id = atomic_inc_return(&coproc_instid);
> +
> +	fp->private_data = instance;
> +	return 0;
> +}
> +
> +static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
> +{
> +	int rc, vasid;
> +	struct vas_tx_win_attr txattr;
> +	struct vas_tx_win_open_attr uattr;
> +	void __user *uptr = (void __user *)arg;
> +	struct vas_window *txwin;
> +	struct coproc_instance *nxti = fp->private_data;
> +
> +	if (!nxti)
> +		return -EINVAL;
> +
> +	/*
> +	 * One window for file descriptor
> +	 */
> +	if (nxti->txwin)
> +		return -EEXIST;
> +
> +	rc = copy_from_user(&uattr, uptr, sizeof(uattr));
> +	if (rc) {
> +		pr_err("%s(): copy_from_user() returns %d\n", __func__, rc);
> +		return -EFAULT;
> +	}
> +
> +	if (uattr.version != 1) {
> +		pr_err("Invalid version\n");
> +		return -EINVAL;
> +	}
> +
> +	vasid = uattr.vas_id;
> +
> +	memset(&txattr, 0, sizeof(struct vas_tx_win_attr));
> +	vas_init_tx_win_attr(&txattr, VAS_COP_TYPE_GZIP);
> +
> +	txattr.lpid = mfspr(SPRN_LPID);
> +	txattr.pidr = mfspr(SPRN_PID);
> +	txattr.user_win = true;
> +	txattr.rsvd_txbuf_count = false;
> +	txattr.pswid = false;
> +	/*
> +	 * txattr.wcreds_max is set to VAS_WCREDS_DEFAULT (1024) in
> +	 * vas-window.c, but can be changed specific to GZIP depends
> +	 * on user space need.
> +	 * If needed to set txattr.wcreds_max here.
> +	 */
> +
> +	pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
> +				mfspr(SPRN_PID));
> +
> +	txwin = vas_tx_win_open(vasid, VAS_COP_TYPE_GZIP, &txattr);
> +	if (IS_ERR(txwin)) {
> +		pr_err("%s() vas_tx_win_open() failed, %ld\n", __func__,
> +					PTR_ERR(txwin));
> +		return PTR_ERR(txwin);
> +	}
> +
> +	nxti->txwin = txwin;
> +
> +	return 0;
> +}
> +
> +static int coproc_release(struct inode *inode, struct file *fp)
> +{
> +	struct coproc_instance *instance;
> +
> +	instance = fp->private_data;
> +
> +	if (instance && instance->txwin) {
> +		vas_win_close(instance->txwin);
> +		instance->txwin = NULL;
> +	}
> +
> +	/*
> +	 * We don't know here if user has other receive windows
> +	 * open, so we can't really call clear_thread_tidr().
> +	 * So, once the process calls set_thread_tidr(), the
> +	 * TIDR value sticks around until process exits, resulting
> +	 * in an extra copy in restore_sprs().
> +	 */
> +
> +	kfree(instance);
> +	fp->private_data = NULL;
> +	atomic_dec(&coproc_instid);
> +
> +	return 0;
> +}
> +
> +static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
> +{
> +	int rc;
> +	pgprot_t prot;
> +	u64 paste_addr;
> +	unsigned long pfn;
> +	struct coproc_instance *instance = fp->private_data;
> +
> +	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
> +		pr_debug("%s(): size 0x%zx, PAGE_SIZE 0x%zx\n", __func__,
> +				(vma->vm_end - vma->vm_start), PAGE_SIZE);
> +		return -EINVAL;
> +	}
> +
> +	/* Ensure instance has an open send window */
> +	if (!instance->txwin) {
> +		pr_err("%s(): No send window open?\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	vas_win_paste_addr(instance->txwin, &paste_addr, NULL);
> +	pfn = paste_addr >> PAGE_SHIFT;
> +
> +	/* flags, page_prot from cxl_mmap(), except we want cachable */
> +	vma->vm_flags |= VM_IO | VM_PFNMAP;
> +	vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
> +
> +	prot = __pgprot(pgprot_val(vma->vm_page_prot) | _PAGE_DIRTY);
> +
> +	rc = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
> +			vma->vm_end - vma->vm_start, prot);
> +
> +	pr_devel("%s(): paste addr %llx at %lx, rc %d\n", __func__,
> +			paste_addr, vma->vm_start, rc);
> +
> +	return rc;
> +}
> +
> +static long coproc_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
> +{
> +	switch (cmd) {
> +	case VAS_TX_WIN_OPEN:
> +		return coproc_ioc_tx_win_open(fp, arg);
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static struct file_operations coproc_fops = {
> +	.open = coproc_open,
> +	.release = coproc_release,
> +	.mmap = coproc_mmap,
> +	.unlocked_ioctl = coproc_ioctl,
> +};
> +

checkpatch didn't run on this series via snowpatch because it doesn't
understand that the other series needs to be applied first. So I ran
checkpatch myself, and it reported:

WARNING: struct file_operations should normally be const
#287: FILE: arch/powerpc/platforms/powernv/vas-api.c:213:
+static struct file_operations coproc_fops = {


> +/*
> + * Supporting only nx-gzip coprocessor type now, but this API code
> + * extended to other coprocessor types later.
> + */
> +int vas_register_coproc_api(struct module *mod)
> +{
> +	int rc = -EINVAL;
> +	dev_t devno;
> +
> +	rc = alloc_chrdev_region(&coproc_device.devt, 1, 1, "nx-gzip");
> +	if (rc) {
> +		pr_err("Unable to allocate coproc major number: %i\n", rc);
> +		return rc;
> +	}
> +
> +	pr_devel("NX-GZIP device allocated, dev [%i,%i]\n",
> +			MAJOR(coproc_device.devt), MINOR(coproc_device.devt));
> +
> +	coproc_device.class = class_create(mod, "nx-gzip");
> +	if (IS_ERR(coproc_device.class)) {
> +		rc = PTR_ERR(coproc_device.class);
> +		pr_err("Unable to create NX-GZIP class %d\n", rc);
> +		goto err_class;
> +	}
> +	coproc_device.class->devnode = coproc_devnode;
> +
> +	coproc_fops.owner = mod;
> +	cdev_init(&coproc_device.cdev, &coproc_fops);
> +
> +	devno = MKDEV(MAJOR(coproc_device.devt), 0);
> +	rc = cdev_add(&coproc_device.cdev, devno, 1);
> +	if (rc) {
> +		pr_err("cdev_add() failed %d\n", rc);
> +		goto err_cdev;
> +	}
> +
> +	coproc_device.device = device_create(coproc_device.class, NULL,
> +			devno, NULL, coproc_dev_name, MINOR(devno));
> +	if (IS_ERR(coproc_device.device)) {
> +		rc = PTR_ERR(coproc_device.device);
> +		pr_err("Unable to create coproc-%d %d\n", MINOR(devno), rc);
> +		goto err;
> +	}
> +
> +	pr_devel("%s: Added dev [%d,%d]\n", __func__, MAJOR(devno),
> +			MINOR(devno));
> +
> +	return 0;
> +
> +err:
> +	cdev_del(&coproc_device.cdev);
> +err_cdev:
> +	class_destroy(coproc_device.class);
> +err_class:
> +	unregister_chrdev_region(coproc_device.devt, 1);
> +	return rc;
> +}
> +EXPORT_SYMBOL_GPL(vas_register_coproc_api);
> +
> +void vas_unregister_coproc_api(void)
> +{
> +	dev_t devno;
> +
> +	cdev_del(&coproc_device.cdev);
> +	devno = MKDEV(MAJOR(coproc_device.devt), 0);
> +	device_destroy(coproc_device.class, devno);
> +
> +	class_destroy(coproc_device.class);
> +	unregister_chrdev_region(coproc_device.devt, 1);
> +}
> +EXPORT_SYMBOL_GPL(vas_unregister_coproc_api);
> diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
> index e9ab851..7484296 100644
> --- a/arch/powerpc/platforms/powernv/vas-window.c
> +++ b/arch/powerpc/platforms/powernv/vas-window.c
> @@ -26,7 +26,7 @@
>   * Compute the paste address region for the window @window using the
>   * ->paste_base_addr and ->paste_win_id_shift we got from device tree.
>   */
> -static void compute_paste_address(struct vas_window *window, u64 *addr, int *len)
> +void vas_win_paste_addr(struct vas_window *window, u64 *addr, int *len)
>  {
>  	int winid;
>  	u64 base, shift;
> @@ -80,7 +80,7 @@ static void *map_paste_region(struct vas_window *txwin)
>  		goto free_name;
>  
>  	txwin->paste_addr_name = name;
> -	compute_paste_address(txwin, &start, &len);
> +	vas_win_paste_addr(txwin, &start, &len);
>  
>  	if (!request_mem_region(start, len, name)) {
>  		pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
> @@ -138,7 +138,7 @@ static void unmap_paste_region(struct vas_window *window)
>  	u64 busaddr_start;
>  
>  	if (window->paste_kaddr) {
> -		compute_paste_address(window, &busaddr_start, &len);
> +		vas_win_paste_addr(window, &busaddr_start, &len);
>  		unmap_region(window->paste_kaddr, busaddr_start, len);
>  		window->paste_kaddr = NULL;
>  		kfree(window->paste_addr_name);
> diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
> index 8c39a7d..a10abed 100644
> --- a/arch/powerpc/platforms/powernv/vas.h
> +++ b/arch/powerpc/platforms/powernv/vas.h
> @@ -431,6 +431,8 @@ struct vas_winctx {
>  extern void vas_return_credit(struct vas_window *window, bool tx);
>  extern struct vas_window *vas_pswid_to_window(struct vas_instance *vinst,
>  						uint32_t pswid);
> +extern void vas_win_paste_addr(struct vas_window *window, u64 *addr,
> +					int *len);
>  
>  static inline int vas_window_pid(struct vas_window *window)
>  {
> -- 
> 1.8.3.1

Re: [PATCH v3 3/9] powerpc/vas: Add VAS user space API

[Haren Myneni]

On Thu, 2020-03-19 at 12:16 +1100, Daniel Axtens wrote:
> Haren Myneni <haren@linux.ibm.com> writes:
> 
> > On power9, userspace can send GZIP compression requests directly to NX
> > once kernel establishes NX channel / window with VAS. This patch provides
> > user space API which allows user space to establish channel using open
> > VAS_TX_WIN_OPEN ioctl, mmap and close operations.
> >
> > Each window corresponds to file descriptor and application can open
> > multiple windows. After the window is opened, VAS_TX_WIN_OPEN icoctl to
> > open a window on specific VAS instance, mmap() system call to map
> > the hardware address of engine's request queue into the application's
> > virtual address space.
> >
> > Then the application can then submit one or more requests to the the
> > engine by using the copy/paste instructions and pasting the CRBs to
> > the virtual address (aka paste_address) returned by mmap().
> >
> > Only NX GZIP coprocessor type is supported right now and allow GZIP
> > engine access via /dev/crypto/nx-gzip device node.
> >
> > Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
> > Signed-off-by: Haren Myneni <haren@linux.ibm.com>
> > ---
> >  arch/powerpc/include/asm/vas.h              |  11 ++
> >  arch/powerpc/platforms/powernv/Makefile     |   2 +-
> >  arch/powerpc/platforms/powernv/vas-api.c    | 290 ++++++++++++++++++++++++++++
> >  arch/powerpc/platforms/powernv/vas-window.c |   6 +-
> >  arch/powerpc/platforms/powernv/vas.h        |   2 +
> >  5 files changed, 307 insertions(+), 4 deletions(-)
> >  create mode 100644 arch/powerpc/platforms/powernv/vas-api.c
> >
> > diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
> > index f93e6b0..e064953 100644
> > --- a/arch/powerpc/include/asm/vas.h
> > +++ b/arch/powerpc/include/asm/vas.h
> > @@ -163,4 +163,15 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
> >   */
> >  int vas_paste_crb(struct vas_window *win, int offset, bool re);
> >  
> > +/*
> > + * Register / unregister coprocessor type to VAS API which will be exported
> > + * to user space. Applications can use this API to open / close window
> > + * which can be used to send / receive requests directly to cooprcessor.
> > + *
> > + * Only NX GZIP coprocessor type is supported now, but this API can be
> > + * used for others in future.
> > + */
> > +int vas_register_coproc_api(struct module *mod);
> > +void vas_unregister_coproc_api(void);
> > +
> >  #endif /* __ASM_POWERPC_VAS_H */
> > diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
> > index 395789f..fe3f0fb 100644
> > --- a/arch/powerpc/platforms/powernv/Makefile
> > +++ b/arch/powerpc/platforms/powernv/Makefile
> > @@ -17,7 +17,7 @@ obj-$(CONFIG_MEMORY_FAILURE)	+= opal-memory-errors.o
> >  obj-$(CONFIG_OPAL_PRD)	+= opal-prd.o
> >  obj-$(CONFIG_PERF_EVENTS) += opal-imc.o
> >  obj-$(CONFIG_PPC_MEMTRACE)	+= memtrace.o
> > -obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o
> > +obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o vas-api.o
> >  obj-$(CONFIG_OCXL_BASE)	+= ocxl.o
> >  obj-$(CONFIG_SCOM_DEBUGFS) += opal-xscom.o
> >  obj-$(CONFIG_PPC_SECURE_BOOT) += opal-secvar.o
> > diff --git a/arch/powerpc/platforms/powernv/vas-api.c b/arch/powerpc/platforms/powernv/vas-api.c
> > new file mode 100644
> > index 0000000..3473a4a
> > --- /dev/null
> > +++ b/arch/powerpc/platforms/powernv/vas-api.c
> > @@ -0,0 +1,290 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * VAS user space API for its accelerators (Only NX-GZIP is supported now)
> > + * Copyright (C) 2019 Haren Myneni, IBM Corp
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/device.h>
> > +#include <linux/cdev.h>
> > +#include <linux/fs.h>
> > +#include <linux/slab.h>
> > +#include <linux/uaccess.h>
> > +#include <asm/vas.h>
> > +#include <uapi/asm/vas-api.h>
> > +#include "vas.h"
> > +
> > +/*
> > + * The driver creates the device node that can be used as follows:
> > + * For NX-GZIP
> > + *
> > + *	fd = open("/dev/crypto/nx-gzip", O_RDWR);
> > + *	rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr);
> > + *	paste_addr = mmap(NULL, PAGE_SIZE, prot, MAP_SHARED, fd, 0ULL).
> > + *	vas_copy(&crb, 0, 1);
> > + *	vas_paste(paste_addr, 0, 1);
> > + *	close(fd) or exit process to close window.
> > + *
> > + * where "vas_copy" and "vas_paste" are defined in copy-paste.h.
> > + * copy/paste returns to the user space directly. So refer NX hardware
> > + * documententation for excat copy/paste usage and completion / error
> > + * conditions.
> > + */
> > +
> > +static char	*coproc_dev_name = "nx-gzip";
> > +static atomic_t	coproc_instid = ATOMIC_INIT(0);
> > +
> > +/*
> > + * Wrapper object for the nx-gzip device - there is just one instance of
> > + * this node for the whole system.
> > + */
> > +static struct coproc_dev {
> > +	struct cdev cdev;
> > +	struct device *device;
> > +	char *name;
> > +	dev_t devt;
> > +	struct class *class;
> > +} coproc_device;
> > +
> > +/*
> > + * One instance per open of a nx-gzip device. Each coproc_instance is
> > + * associated with a VAS window after the caller issues
> > + * VAS_GZIP_TX_WIN_OPEN ioctl.
> > + */
> > +struct coproc_instance {
> > +	int id;
> > +	struct vas_window *txwin;
> > +};
> > +
> > +static char *coproc_devnode(struct device *dev, umode_t *mode)
> > +{
> > +	return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev));
> > +}
> > +
> > +static int coproc_open(struct inode *inode, struct file *fp)
> > +{
> > +	struct coproc_instance *instance;
> > +
> > +	instance = kzalloc(sizeof(*instance), GFP_KERNEL);
> > +	if (!instance)
> > +		return -ENOMEM;
> > +
> > +	instance->id = atomic_inc_return(&coproc_instid);
> > +
> > +	fp->private_data = instance;
> > +	return 0;
> > +}
> > +
> > +static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
> > +{
> > +	int rc, vasid;
> > +	struct vas_tx_win_attr txattr;
> > +	struct vas_tx_win_open_attr uattr;
> > +	void __user *uptr = (void __user *)arg;
> > +	struct vas_window *txwin;
> > +	struct coproc_instance *nxti = fp->private_data;
> > +
> > +	if (!nxti)
> > +		return -EINVAL;
> > +
> > +	/*
> > +	 * One window for file descriptor
> > +	 */
> > +	if (nxti->txwin)
> > +		return -EEXIST;
> > +
> > +	rc = copy_from_user(&uattr, uptr, sizeof(uattr));
> > +	if (rc) {
> > +		pr_err("%s(): copy_from_user() returns %d\n", __func__, rc);
> > +		return -EFAULT;
> > +	}
> > +
> > +	if (uattr.version != 1) {
> > +		pr_err("Invalid version\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	vasid = uattr.vas_id;
> > +
> > +	memset(&txattr, 0, sizeof(struct vas_tx_win_attr));
> > +	vas_init_tx_win_attr(&txattr, VAS_COP_TYPE_GZIP);
> > +
> > +	txattr.lpid = mfspr(SPRN_LPID);
> > +	txattr.pidr = mfspr(SPRN_PID);
> > +	txattr.user_win = true;
> > +	txattr.rsvd_txbuf_count = false;
> > +	txattr.pswid = false;
> > +	/*
> > +	 * txattr.wcreds_max is set to VAS_WCREDS_DEFAULT (1024) in
> > +	 * vas-window.c, but can be changed specific to GZIP depends
> > +	 * on user space need.
> > +	 * If needed to set txattr.wcreds_max here.
> > +	 */
> > +
> > +	pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
> > +				mfspr(SPRN_PID));
> > +
> > +	txwin = vas_tx_win_open(vasid, VAS_COP_TYPE_GZIP, &txattr);
> > +	if (IS_ERR(txwin)) {
> > +		pr_err("%s() vas_tx_win_open() failed, %ld\n", __func__,
> > +					PTR_ERR(txwin));
> > +		return PTR_ERR(txwin);
> > +	}
> > +
> > +	nxti->txwin = txwin;
> > +
> > +	return 0;
> > +}
> > +
> > +static int coproc_release(struct inode *inode, struct file *fp)
> > +{
> > +	struct coproc_instance *instance;
> > +
> > +	instance = fp->private_data;
> > +
> > +	if (instance && instance->txwin) {
> > +		vas_win_close(instance->txwin);
> > +		instance->txwin = NULL;
> > +	}
> > +
> > +	/*
> > +	 * We don't know here if user has other receive windows
> > +	 * open, so we can't really call clear_thread_tidr().
> > +	 * So, once the process calls set_thread_tidr(), the
> > +	 * TIDR value sticks around until process exits, resulting
> > +	 * in an extra copy in restore_sprs().
> > +	 */
> > +
> > +	kfree(instance);
> > +	fp->private_data = NULL;
> > +	atomic_dec(&coproc_instid);
> > +
> > +	return 0;
> > +}
> > +
> > +static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
> > +{
> > +	int rc;
> > +	pgprot_t prot;
> > +	u64 paste_addr;
> > +	unsigned long pfn;
> > +	struct coproc_instance *instance = fp->private_data;
> > +
> > +	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
> > +		pr_debug("%s(): size 0x%zx, PAGE_SIZE 0x%zx\n", __func__,
> > +				(vma->vm_end - vma->vm_start), PAGE_SIZE);
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* Ensure instance has an open send window */
> > +	if (!instance->txwin) {
> > +		pr_err("%s(): No send window open?\n", __func__);
> > +		return -EINVAL;
> > +	}
> > +
> > +	vas_win_paste_addr(instance->txwin, &paste_addr, NULL);
> > +	pfn = paste_addr >> PAGE_SHIFT;
> > +
> > +	/* flags, page_prot from cxl_mmap(), except we want cachable */
> > +	vma->vm_flags |= VM_IO | VM_PFNMAP;
> > +	vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
> > +
> > +	prot = __pgprot(pgprot_val(vma->vm_page_prot) | _PAGE_DIRTY);
> > +
> > +	rc = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
> > +			vma->vm_end - vma->vm_start, prot);
> > +
> > +	pr_devel("%s(): paste addr %llx at %lx, rc %d\n", __func__,
> > +			paste_addr, vma->vm_start, rc);
> > +
> > +	return rc;
> > +}
> > +
> > +static long coproc_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
> > +{
> > +	switch (cmd) {
> > +	case VAS_TX_WIN_OPEN:
> > +		return coproc_ioc_tx_win_open(fp, arg);
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +}
> > +
> > +static struct file_operations coproc_fops = {
> > +	.open = coproc_open,
> > +	.release = coproc_release,
> > +	.mmap = coproc_mmap,
> > +	.unlocked_ioctl = coproc_ioctl,
> > +};
> > +
> 
> checkpatch didn't run on this series via snowpatch because it doesn't
> understand that the other series needs to be applied first. So I ran
> checkpatch myself, and it reported:
> 
> WARNING: struct file_operations should normally be const
> #287: FILE: arch/powerpc/platforms/powernv/vas-api.c:213:
> +static struct file_operations coproc_fops = {

No I did run checkpatch on all patches and ignored this warning.
Could not use const as updating module owner later in
vas_register_coproc_api()

coproc_fops.owner = mod;

> 
> 
> > +/*
> > + * Supporting only nx-gzip coprocessor type now, but this API code
> > + * extended to other coprocessor types later.
> > + */
> > +int vas_register_coproc_api(struct module *mod)
> > +{
> > +	int rc = -EINVAL;
> > +	dev_t devno;
> > +
> > +	rc = alloc_chrdev_region(&coproc_device.devt, 1, 1, "nx-gzip");
> > +	if (rc) {
> > +		pr_err("Unable to allocate coproc major number: %i\n", rc);
> > +		return rc;
> > +	}
> > +
> > +	pr_devel("NX-GZIP device allocated, dev [%i,%i]\n",
> > +			MAJOR(coproc_device.devt), MINOR(coproc_device.devt));
> > +
> > +	coproc_device.class = class_create(mod, "nx-gzip");
> > +	if (IS_ERR(coproc_device.class)) {
> > +		rc = PTR_ERR(coproc_device.class);
> > +		pr_err("Unable to create NX-GZIP class %d\n", rc);
> > +		goto err_class;
> > +	}
> > +	coproc_device.class->devnode = coproc_devnode;
> > +
> > +	coproc_fops.owner = mod;
> > +	cdev_init(&coproc_device.cdev, &coproc_fops);
> > +
> > +	devno = MKDEV(MAJOR(coproc_device.devt), 0);
> > +	rc = cdev_add(&coproc_device.cdev, devno, 1);
> > +	if (rc) {
> > +		pr_err("cdev_add() failed %d\n", rc);
> > +		goto err_cdev;
> > +	}
> > +
> > +	coproc_device.device = device_create(coproc_device.class, NULL,
> > +			devno, NULL, coproc_dev_name, MINOR(devno));
> > +	if (IS_ERR(coproc_device.device)) {
> > +		rc = PTR_ERR(coproc_device.device);
> > +		pr_err("Unable to create coproc-%d %d\n", MINOR(devno), rc);
> > +		goto err;
> > +	}
> > +
> > +	pr_devel("%s: Added dev [%d,%d]\n", __func__, MAJOR(devno),
> > +			MINOR(devno));
> > +
> > +	return 0;
> > +
> > +err:
> > +	cdev_del(&coproc_device.cdev);
> > +err_cdev:
> > +	class_destroy(coproc_device.class);
> > +err_class:
> > +	unregister_chrdev_region(coproc_device.devt, 1);
> > +	return rc;
> > +}
> > +EXPORT_SYMBOL_GPL(vas_register_coproc_api);
> > +
> > +void vas_unregister_coproc_api(void)
> > +{
> > +	dev_t devno;
> > +
> > +	cdev_del(&coproc_device.cdev);
> > +	devno = MKDEV(MAJOR(coproc_device.devt), 0);
> > +	device_destroy(coproc_device.class, devno);
> > +
> > +	class_destroy(coproc_device.class);
> > +	unregister_chrdev_region(coproc_device.devt, 1);
> > +}
> > +EXPORT_SYMBOL_GPL(vas_unregister_coproc_api);
> > diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
> > index e9ab851..7484296 100644
> > --- a/arch/powerpc/platforms/powernv/vas-window.c
> > +++ b/arch/powerpc/platforms/powernv/vas-window.c
> > @@ -26,7 +26,7 @@
> >   * Compute the paste address region for the window @window using the
> >   * ->paste_base_addr and ->paste_win_id_shift we got from device tree.
> >   */
> > -static void compute_paste_address(struct vas_window *window, u64 *addr, int *len)
> > +void vas_win_paste_addr(struct vas_window *window, u64 *addr, int *len)
> >  {
> >  	int winid;
> >  	u64 base, shift;
> > @@ -80,7 +80,7 @@ static void *map_paste_region(struct vas_window *txwin)
> >  		goto free_name;
> >  
> >  	txwin->paste_addr_name = name;
> > -	compute_paste_address(txwin, &start, &len);
> > +	vas_win_paste_addr(txwin, &start, &len);
> >  
> >  	if (!request_mem_region(start, len, name)) {
> >  		pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
> > @@ -138,7 +138,7 @@ static void unmap_paste_region(struct vas_window *window)
> >  	u64 busaddr_start;
> >  
> >  	if (window->paste_kaddr) {
> > -		compute_paste_address(window, &busaddr_start, &len);
> > +		vas_win_paste_addr(window, &busaddr_start, &len);
> >  		unmap_region(window->paste_kaddr, busaddr_start, len);
> >  		window->paste_kaddr = NULL;
> >  		kfree(window->paste_addr_name);
> > diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
> > index 8c39a7d..a10abed 100644
> > --- a/arch/powerpc/platforms/powernv/vas.h
> > +++ b/arch/powerpc/platforms/powernv/vas.h
> > @@ -431,6 +431,8 @@ struct vas_winctx {
> >  extern void vas_return_credit(struct vas_window *window, bool tx);
> >  extern struct vas_window *vas_pswid_to_window(struct vas_instance *vinst,
> >  						uint32_t pswid);
> > +extern void vas_win_paste_addr(struct vas_window *window, u64 *addr,
> > +					int *len);
> >  
> >  static inline int vas_window_pid(struct vas_window *window)
> >  {
> > -- 
> > 1.8.3.1

Re: [PATCH v3 3/9] powerpc/vas: Add VAS user space API

[Daniel Axtens]

Haren Myneni <haren@linux.ibm.com> writes:

> On power9, userspace can send GZIP compression requests directly to NX
> once kernel establishes NX channel / window with VAS. This patch provides
> user space API which allows user space to establish channel using open
> VAS_TX_WIN_OPEN ioctl, mmap and close operations.
>
> Each window corresponds to file descriptor and application can open
> multiple windows. After the window is opened, VAS_TX_WIN_OPEN icoctl to
> open a window on specific VAS instance, mmap() system call to map
> the hardware address of engine's request queue into the application's
> virtual address space.
>
> Then the application can then submit one or more requests to the the
> engine by using the copy/paste instructions and pasting the CRBs to
> the virtual address (aka paste_address) returned by mmap().
>
> Only NX GZIP coprocessor type is supported right now and allow GZIP
> engine access via /dev/crypto/nx-gzip device node.
>
> Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
> Signed-off-by: Haren Myneni <haren@linux.ibm.com>
> ---
>  arch/powerpc/include/asm/vas.h              |  11 ++
>  arch/powerpc/platforms/powernv/Makefile     |   2 +-
>  arch/powerpc/platforms/powernv/vas-api.c    | 290 ++++++++++++++++++++++++++++
>  arch/powerpc/platforms/powernv/vas-window.c |   6 +-
>  arch/powerpc/platforms/powernv/vas.h        |   2 +
>  5 files changed, 307 insertions(+), 4 deletions(-)
>  create mode 100644 arch/powerpc/platforms/powernv/vas-api.c
>
> diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
> index f93e6b0..e064953 100644
> --- a/arch/powerpc/include/asm/vas.h
> +++ b/arch/powerpc/include/asm/vas.h
> @@ -163,4 +163,15 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
>   */
>  int vas_paste_crb(struct vas_window *win, int offset, bool re);
>  
> +/*
> + * Register / unregister coprocessor type to VAS API which will be exported
> + * to user space. Applications can use this API to open / close window
> + * which can be used to send / receive requests directly to cooprcessor.
> + *
> + * Only NX GZIP coprocessor type is supported now, but this API can be
> + * used for others in future.
> + */
> +int vas_register_coproc_api(struct module *mod);
> +void vas_unregister_coproc_api(void);
> +
>  #endif /* __ASM_POWERPC_VAS_H */
> diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
> index 395789f..fe3f0fb 100644
> --- a/arch/powerpc/platforms/powernv/Makefile
> +++ b/arch/powerpc/platforms/powernv/Makefile
> @@ -17,7 +17,7 @@ obj-$(CONFIG_MEMORY_FAILURE)	+= opal-memory-errors.o
>  obj-$(CONFIG_OPAL_PRD)	+= opal-prd.o
>  obj-$(CONFIG_PERF_EVENTS) += opal-imc.o
>  obj-$(CONFIG_PPC_MEMTRACE)	+= memtrace.o
> -obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o
> +obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o vas-api.o
>  obj-$(CONFIG_OCXL_BASE)	+= ocxl.o
>  obj-$(CONFIG_SCOM_DEBUGFS) += opal-xscom.o
>  obj-$(CONFIG_PPC_SECURE_BOOT) += opal-secvar.o
> diff --git a/arch/powerpc/platforms/powernv/vas-api.c b/arch/powerpc/platforms/powernv/vas-api.c
> new file mode 100644
> index 0000000..3473a4a
> --- /dev/null
> +++ b/arch/powerpc/platforms/powernv/vas-api.c
> @@ -0,0 +1,290 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * VAS user space API for its accelerators (Only NX-GZIP is supported now)
> + * Copyright (C) 2019 Haren Myneni, IBM Corp
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/cdev.h>
> +#include <linux/fs.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +#include <asm/vas.h>
> +#include <uapi/asm/vas-api.h>
> +#include "vas.h"
> +
> +/*
> + * The driver creates the device node that can be used as follows:
> + * For NX-GZIP
> + *
> + *	fd = open("/dev/crypto/nx-gzip", O_RDWR);
> + *	rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr);
> + *	paste_addr = mmap(NULL, PAGE_SIZE, prot, MAP_SHARED, fd, 0ULL).
> + *	vas_copy(&crb, 0, 1);
> + *	vas_paste(paste_addr, 0, 1);
> + *	close(fd) or exit process to close window.
> + *
> + * where "vas_copy" and "vas_paste" are defined in copy-paste.h.
> + * copy/paste returns to the user space directly. So refer NX hardware
> + * documententation for excat copy/paste usage and completion / error
> + * conditions.
> + */
> +
> +static char	*coproc_dev_name = "nx-gzip";
> +static atomic_t	coproc_instid = ATOMIC_INIT(0);
> +
> +/*
> + * Wrapper object for the nx-gzip device - there is just one instance of
> + * this node for the whole system.
> + */
> +static struct coproc_dev {
> +	struct cdev cdev;
> +	struct device *device;
> +	char *name;
> +	dev_t devt;
> +	struct class *class;
> +} coproc_device;
> +
> +/*
> + * One instance per open of a nx-gzip device. Each coproc_instance is
> + * associated with a VAS window after the caller issues
> + * VAS_GZIP_TX_WIN_OPEN ioctl.
> + */
> +struct coproc_instance {
> +	int id;
> +	struct vas_window *txwin;
> +};
> +
> +static char *coproc_devnode(struct device *dev, umode_t *mode)
> +{
> +	return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev));
> +}
> +
> +static int coproc_open(struct inode *inode, struct file *fp)
> +{
> +	struct coproc_instance *instance;
> +
> +	instance = kzalloc(sizeof(*instance), GFP_KERNEL);
> +	if (!instance)
> +		return -ENOMEM;
> +
> +	instance->id = atomic_inc_return(&coproc_instid);

I don't understand what this instance->id field does - I can't find any
other uses of it in these series.

I'm also not sure that this gives you a unique id - you increment it
here and decrement it in coproc_release, but I'm not sure what prevents
the same ID being given to multiple instances, e.g. the following
sequence

coproc_open(inode,    file A) -> instance with id 0, coproc_instid = 1
coproc_open(inode,    file B) -> instance with id 1, coproc_instid = 2
coproc_release(inode, file A) -> release id 0, coproc_instid = 1
coproc_open(inode,    file C) -> instance with id 1, coproc_instid = 2

File B and C both have ID = 1, unless I'm misunderstanding something.

> +
> +	fp->private_data = instance;
> +	return 0;
> +}
> +
> +static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
> +{
> +	int rc, vasid;
> +	struct vas_tx_win_attr txattr;
> +	struct vas_tx_win_open_attr uattr;
> +	void __user *uptr = (void __user *)arg;
> +	struct vas_window *txwin;
> +	struct coproc_instance *nxti = fp->private_data;
> +
> +	if (!nxti)
> +		return -EINVAL;
> +
> +	/*
> +	 * One window for file descriptor
> +	 */
> +	if (nxti->txwin)
> +		return -EEXIST;
> +
> +	rc = copy_from_user(&uattr, uptr, sizeof(uattr));
> +	if (rc) {
> +		pr_err("%s(): copy_from_user() returns %d\n", __func__, rc);
> +		return -EFAULT;
> +	}
> +
> +	if (uattr.version != 1) {
> +		pr_err("Invalid version\n");
> +		return -EINVAL;
> +	}
> +
> +	vasid = uattr.vas_id;
> +
> +	memset(&txattr, 0, sizeof(struct vas_tx_win_attr));

You could define txattr with `struct vas_tx_win_attr txattr = {};` and
avoid the explicit memset.

> +	vas_init_tx_win_attr(&txattr, VAS_COP_TYPE_GZIP);
> +
> +	txattr.lpid = mfspr(SPRN_LPID);
> +	txattr.pidr = mfspr(SPRN_PID);
> +	txattr.user_win = true;
> +	txattr.rsvd_txbuf_count = false;
> +	txattr.pswid = false;
> +	/*
> +	 * txattr.wcreds_max is set to VAS_WCREDS_DEFAULT (1024) in
> +	 * vas-window.c, but can be changed specific to GZIP depends
> +	 * on user space need.
> +	 * If needed to set txattr.wcreds_max here.
> +	 */

Who could set this? You mention userspace need but it looks like the
user cannot set this. Is this a message to future kernel developers?

> +
> +	pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
> +				mfspr(SPRN_PID));
> +
> +	txwin = vas_tx_win_open(vasid, VAS_COP_TYPE_GZIP, &txattr);
> +	if (IS_ERR(txwin)) {
> +		pr_err("%s() vas_tx_win_open() failed, %ld\n", __func__,
> +					PTR_ERR(txwin));
> +		return PTR_ERR(txwin);
> +	}
> +
> +	nxti->txwin = txwin;
> +
> +	return 0;
> +}
> +
> +static int coproc_release(struct inode *inode, struct file *fp)
> +{
> +	struct coproc_instance *instance;
> +
> +	instance = fp->private_data;
> +
> +	if (instance && instance->txwin) {
> +		vas_win_close(instance->txwin);
> +		instance->txwin = NULL;
> +	}
> +
> +	/*
> +	 * We don't know here if user has other receive windows
> +	 * open, so we can't really call clear_thread_tidr().
> +	 * So, once the process calls set_thread_tidr(), the
> +	 * TIDR value sticks around until process exits, resulting
> +	 * in an extra copy in restore_sprs().
> +	 */
> +
> +	kfree(instance);
> +	fp->private_data = NULL;
> +	atomic_dec(&coproc_instid);
> +
> +	return 0;
> +}
> +
> +static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
> +{
> +	int rc;
> +	pgprot_t prot;
> +	u64 paste_addr;
> +	unsigned long pfn;
> +	struct coproc_instance *instance = fp->private_data;
> +
> +	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
> +		pr_debug("%s(): size 0x%zx, PAGE_SIZE 0x%zx\n", __func__,
> +				(vma->vm_end - vma->vm_start), PAGE_SIZE);
> +		return -EINVAL;
> +	}
> +
> +	/* Ensure instance has an open send window */
> +	if (!instance->txwin) {
> +		pr_err("%s(): No send window open?\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	vas_win_paste_addr(instance->txwin, &paste_addr, NULL);
> +	pfn = paste_addr >> PAGE_SHIFT;
> +
> +	/* flags, page_prot from cxl_mmap(), except we want cachable */
> +	vma->vm_flags |= VM_IO | VM_PFNMAP;
> +	vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
> +
> +	prot = __pgprot(pgprot_val(vma->vm_page_prot) | _PAGE_DIRTY);
> +
> +	rc = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
> +			vma->vm_end - vma->vm_start, prot);
> +
> +	pr_devel("%s(): paste addr %llx at %lx, rc %d\n", __func__,
> +			paste_addr, vma->vm_start, rc);
> +
> +	return rc;
> +}
> +
> +static long coproc_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
> +{
> +	switch (cmd) {
> +	case VAS_TX_WIN_OPEN:
> +		return coproc_ioc_tx_win_open(fp, arg);
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static struct file_operations coproc_fops = {
> +	.open = coproc_open,
> +	.release = coproc_release,
> +	.mmap = coproc_mmap,
> +	.unlocked_ioctl = coproc_ioctl,
> +};
> +
> +/*
> + * Supporting only nx-gzip coprocessor type now, but this API code
> + * extended to other coprocessor types later.
> + */
> +int vas_register_coproc_api(struct module *mod)
> +{
> +	int rc = -EINVAL;
> +	dev_t devno;
> +
> +	rc = alloc_chrdev_region(&coproc_device.devt, 1, 1, "nx-gzip");
> +	if (rc) {
> +		pr_err("Unable to allocate coproc major number: %i\n", rc);
> +		return rc;
> +	}
> +
> +	pr_devel("NX-GZIP device allocated, dev [%i,%i]\n",
> +			MAJOR(coproc_device.devt), MINOR(coproc_device.devt));
> +
> +	coproc_device.class = class_create(mod, "nx-gzip");
> +	if (IS_ERR(coproc_device.class)) {
> +		rc = PTR_ERR(coproc_device.class);
> +		pr_err("Unable to create NX-GZIP class %d\n", rc);
> +		goto err_class;
> +	}
> +	coproc_device.class->devnode = coproc_devnode;
> +
> +	coproc_fops.owner = mod;
> +	cdev_init(&coproc_device.cdev, &coproc_fops);

Looking into this coproc_fops thing more:

I find this API very confusing. The comment at the top of the function
says it will be extended, but there's only one coproc_fops, so currently
it can only be instantiated once and owned by one module. Much of the
rest of that function is also very much based around the nx-gzip
coprocessor.

I'm not fully certain about how this should work, but I think probably
it either needs to be fully generic or fully nx-gzip only for now. I
would make it fully nx-gzip only and extend it later, but I'm not fussy.

> +
> +	devno = MKDEV(MAJOR(coproc_device.devt), 0);
> +	rc = cdev_add(&coproc_device.cdev, devno, 1);
> +	if (rc) {
> +		pr_err("cdev_add() failed %d\n", rc);
> +		goto err_cdev;
> +	}
> +
> +	coproc_device.device = device_create(coproc_device.class, NULL,
> +			devno, NULL, coproc_dev_name, MINOR(devno));
> +	if (IS_ERR(coproc_device.device)) {
> +		rc = PTR_ERR(coproc_device.device);
> +		pr_err("Unable to create coproc-%d %d\n", MINOR(devno), rc);
> +		goto err;
> +	}
> +
> +	pr_devel("%s: Added dev [%d,%d]\n", __func__, MAJOR(devno),
> +			MINOR(devno));
> +
> +	return 0;
> +
> +err:
> +	cdev_del(&coproc_device.cdev);
> +err_cdev:
> +	class_destroy(coproc_device.class);
> +err_class:
> +	unregister_chrdev_region(coproc_device.devt, 1);
> +	return rc;
> +}
> +EXPORT_SYMBOL_GPL(vas_register_coproc_api);
> +
> +void vas_unregister_coproc_api(void)
> +{
> +	dev_t devno;
> +
> +	cdev_del(&coproc_device.cdev);
> +	devno = MKDEV(MAJOR(coproc_device.devt), 0);
> +	device_destroy(coproc_device.class, devno);
> +
> +	class_destroy(coproc_device.class);
> +	unregister_chrdev_region(coproc_device.devt, 1);
> +}
> +EXPORT_SYMBOL_GPL(vas_unregister_coproc_api);
> diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
> index e9ab851..7484296 100644
> --- a/arch/powerpc/platforms/powernv/vas-window.c
> +++ b/arch/powerpc/platforms/powernv/vas-window.c
> @@ -26,7 +26,7 @@
>   * Compute the paste address region for the window @window using the
>   * ->paste_base_addr and ->paste_win_id_shift we got from device tree.
>   */
> -static void compute_paste_address(struct vas_window *window, u64 *addr, int *len)
> +void vas_win_paste_addr(struct vas_window *window, u64 *addr, int *len)
>  {
>  	int winid;
>  	u64 base, shift;
> @@ -80,7 +80,7 @@ static void *map_paste_region(struct vas_window *txwin)
>  		goto free_name;
>  
>  	txwin->paste_addr_name = name;
> -	compute_paste_address(txwin, &start, &len);
> +	vas_win_paste_addr(txwin, &start, &len);
>  
>  	if (!request_mem_region(start, len, name)) {
>  		pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
> @@ -138,7 +138,7 @@ static void unmap_paste_region(struct vas_window *window)
>  	u64 busaddr_start;
>  
>  	if (window->paste_kaddr) {
> -		compute_paste_address(window, &busaddr_start, &len);
> +		vas_win_paste_addr(window, &busaddr_start, &len);
>  		unmap_region(window->paste_kaddr, busaddr_start, len);
>  		window->paste_kaddr = NULL;
>  		kfree(window->paste_addr_name);
> diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
> index 8c39a7d..a10abed 100644
> --- a/arch/powerpc/platforms/powernv/vas.h
> +++ b/arch/powerpc/platforms/powernv/vas.h
> @@ -431,6 +431,8 @@ struct vas_winctx {
>  extern void vas_return_credit(struct vas_window *window, bool tx);
>  extern struct vas_window *vas_pswid_to_window(struct vas_instance *vinst,
>  						uint32_t pswid);
> +extern void vas_win_paste_addr(struct vas_window *window, u64 *addr,
> +					int *len);
>  
>  static inline int vas_window_pid(struct vas_window *window)
>  {
> -- 
> 1.8.3.1

Re: [PATCH v3 9/9] Documentation/powerpc: VAS API

[Daniel Axtens]

Hi Haren,

This is good documentation.

> Power9 introduced Virtual Accelerator Switchboard (VAS) which allows
> userspace to communicate with Nest Accelerator (NX) directly. But
> kernel has to establish channel to NX for userspace. This document
> describes user space API that application can use to establish
> communication channel.
>
> Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
> Signed-off-by: Haren Myneni <haren@linux.ibm.com>
> ---
>  Documentation/powerpc/index.rst   |   1 +
>  Documentation/powerpc/vas-api.rst | 246 ++++++++++++++++++++++++++++++++++++++
>  2 files changed, 247 insertions(+)
>  create mode 100644 Documentation/powerpc/vas-api.rst
>
> diff --git a/Documentation/powerpc/index.rst b/Documentation/powerpc/index.rst
> index 0d45f0f..afe2d5e 100644
> --- a/Documentation/powerpc/index.rst
> +++ b/Documentation/powerpc/index.rst
> @@ -30,6 +30,7 @@ powerpc
>      syscall64-abi
>      transactional_memory
>      ultravisor
> +    vas-api
>  
>  .. only::  subproject and html
>  
> diff --git a/Documentation/powerpc/vas-api.rst b/Documentation/powerpc/vas-api.rst
> new file mode 100644
> index 0000000..13ce4e7
> --- /dev/null
> +++ b/Documentation/powerpc/vas-api.rst
> @@ -0,0 +1,246 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +.. _VAS-API:
> +
> +===================================================
> +Virtual Accelerator Switchboard (VAS) userspace API
> +===================================================
> +
> +Introduction
> +============
> +
> +Power9 processor introduced Virtual Accelerator Switchboard (VAS) which
> +allows both userspace and kernel communicate to co-processor
> +(hardware accelerator) referred to as the Nest Accelerator (NX). The NX
> +unit comprises of one or more hardware engines or co-processor types
> +such as 842 compression, GZIP compression and encryption. On power9,
> +userspace applications will have access to only GZIP Compression engine
> +which supports ZLIB and GZIP compression algorithms in the hardware.
> +
> +To communicate with NX, kernel has to establish a channel or window and
> +then requests can be submitted directly without kernel involvement.
> +Requests to the GZIP engine must be formatted as a co-processor Request
> +Block (CRB) and these CRBs must be submitted to the NX using COPY/PASTE
> +instructions to paste the CRB to hardware address that is associated with
> +the engine's request queue.
> +
> +The GZIP engine provides two priority levels of requests: Normal and
> +High. Only Normal requests are supported from userspace right now.
> +
> +This document explains userspace API that is used to interact with
> +kernel to setup channel / window which can be used to send compression
> +requests directly to NX accelerator.
> +
> +
> +Overview
> +========
> +
> +Application access to the GZIP engine is provided through
> +/dev/crypto/nx-gzip device node implemented by the VAS/NX device driver.
> +An application must open the /dev/crypto/nx-gzip device to obtain a file
> +descriptor (fd). Then should issue VAS_TX_WIN_OPEN ioctl with this fd to
> +establish connection to the engine. It means send window is opened on GZIP
> +engine for this process. Once a connection is established, the application
> +should use the mmap() system call to map the hardware address of engine's
> +request queue into the application's virtual address space.
> +
> +The application can then submit one or more requests to the the engine by
> +using copy/paste instructions and pasting the CRBs to the virtual address
> +(aka paste_address) returned by mmap(). User space can close the
> +established connection or send window by closing the file descriptior
> +(close(fd)) or upon the process exit.
> +
> +Note that applications can send several requests with the same window or
> +can establish multiple windows, but one window for each file descriptor.
> +
> +Following sections provide additional details and references about the
> +individual steps.
> +
> +NX-GZIP Device Node
> +===================
> +
> +There is one /dev/crypto/nx-gzip node in the system and it provides
> +access to all GZIP engines in the system. The only valid operations on
> +/dev/crypto/nx-gzip are:
> +
> +	* open() the device for read and write.
> +	* issue VAS_TX_WIN_OPEN ioctl
> +	* mmap() the engine's request queue into application's virtual
> +	  address space (i.e. get a paste_address for the co-processor
> +	  engine).
> +	* close the device node.
> +
> +Other file operations on this device node are undefined.
> +
> +Note that the copy and paste operations go directly to the hardware and
> +do not go through this device. Refer COPY/PASTE document for more
> +details.
> +
> +Although a system may have several instances of the NX co-processor
> +engines (typically, one per P9 chip) there is just one
> +/dev/crypto/nx-gzip device node in the system. When the nx-gzip device
> +node is opened, Kernel opens send window on a suitable instance of NX
> +accelerator. It finds CPU on which the user process is executing and
> +determine the NX instance for the corresponding chip on which this CPU
> +belongs.
> +
> +Applications may chose a specific instance of the NX co-processor using
> +the vas_id field in the VAS_TX_WIN_OPEN ioctl as detailed below.
> +
> +A userspace library libnxz is available here but still in development:
> +	 https://github.com/abalib/power-gzip
> +
> +Applications that use inflate / deflate calls can link with libnxz
> +instead of libz and use NX GZIP compression without any modification.
> +
> +Open /dev/crypto/nx-gzip
> +========================
> +
> +The nx-gzip device should be opened for read and write. No special
> +privileges are needed to open the device. Each window coreesponds to one

s/coreesponds/corresponds/

> +file descriptor. So if the userspace process needs multiple windows,
> +several open calls have to be issued.
> +
> +See open(2) system call man pages for other details such as return values,
> +error codes and restrictions.
> +codes and restrictions.

You have 'codes and restrictions' twice here.

> +
> +VAS_TX_WIN_OPEN ioctl
> +=====================
> +
> +Applications should use the VAS_TX_WIN_OPEN ioctl as follows to establish
> +a connection with NX co-processor engine:
> +
> +	::
> +		struct vas_tx_win_open_attr {
> +			__u32   version;
> +			__s16   vas_id; /* specific instance of vas or -1
> +						for default */
> +			__u16   reserved1;
> +			__u64   flags;	/* For future use */
> +			__u64   reserved2[6];
> +		};
> +
> +	version: The version field must be currently set to 1.
> +	vas_id: If '-1' is passed, kernel will make a best-effort attempt
> +		to assign an optimal instance of NX for the process. To
> +		select the specific VAS instance, refer
> +		"Discovery of available VAS engines" section below.
> +
> +	flags, reserved1 and reserved2[6] fields are for future extension
> +	and must be set to 0.
> +
> +	The attributes attr for the VAS_TX_WIN_OPEN ioctl are defined as
> +	follows:
> +		#define VAS_MAGIC 'v'
> +		#define VAS_TX_WIN_OPEN _IOW(VAS_MAGIC, 1,
> +						struct vas_tx_win_open_attr)
> +
> +		struct vas_tx_win_open_attr attr;
> +		rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr);
> +
> +	The VAS_TX_WIN_OPEN ioctl returns 0 on success. On errors, it
> +	returns -1 and sets the errno variable to indicate the error.
> +
> +	Error conditions:
> +		EINVAL	fd does not refer to a valid VAS device.
> +		EINVAL	Invalid vas ID
> +		EINVAL	version is not set with proper value
> +		EEXIST	Window is already opened for the given fd
> +		ENOMEM	Memory is not available to allocate window
> +		ENOSPC	System has too many active windows (connections)
> +			opened
> +		EINVAL	reserved fields are not set to 0.
> +
> +	See the ioctl(2) man page for more details, error codes and
> +	restrictions.
> +
> +mmap() NX-GZIP device
> +=====================
> +
> +The mmap() system call for a NX-GZIP device fd returns a paste_address
> +that the application can use to copy/paste its CRB to the hardware engines.
> +	::
> +
> +		paste_addr = mmap(addr, size, prot, flags, fd, offset);
> +
> +	Only restrictions on mmap for a NX-GZIP device fd are:
> +		* size should be 4K page size

Patch 3 seems to allow a 64k page if the system is compiled for 64k
pages... Should it restrict it to 4K?

> +		* offset parameter should be 0ULL
> +
> +	Refer to mmap(2) man page for additional details/restrictions.
> +	In addition to the error conditions listed on the mmap(2) man
> +	page, can also fail with one of the following error codes:
> +
> +		EINVAL	fd is not associated with an open window
> +			(i.e mmap() does not follow a successful call
> +			to the VAS_TX_WIN_OPEN ioctl).
> +		EINVAL	offset field is not 0ULL.
> +
> +Discovery of available VAS engines
> +==================================
> +
> +Each available VAS instance in the system will have a device tree node
> +like /proc/device-tree/vas@* or /proc/device-tree/xscom@*/vas@*.
> +Determine the chip or VAS instance and use the corresponding ibm,vas-id
> +property value in this node to select specific VAS instance.
> +
> +Copy/Paste operations
> +=====================
> +
> +Applications should use the copy and paste instructions defined in the RFC
> +to copy/paste the CRB.

In which RFC?

> +
> +CRB Specification and use NX
> +============================
> +
> +Applications should format requests to the co-processor using the
> +co-processor Request Block (CRBs). Refer NX workbook for the format of
> +CRB and use NX from userspace such as sending requests and checking
> +request status.

Where would someone find the NX workbook?

Regards,
Daniel

> +
> +Simple example
> +==============
> +
> +	::
> +		int use_nx_gzip()
> +		{
> +			int rc, fd;
> +			void *addr;
> +			struct vas_setup_attr txattr;
> +
> +			fd = open("/dev/crypto/nx-gzip", O_RDWR);
> +			if (fd < 0) {
> +				fprintf(stderr, "open nx-gzip failed\n");
> +				return -1;
> +			}
> +			memset(&txattr, 0, sizeof(txattr));
> +			txattr.version = 1;
> +			txattr.vas_id = -1
> +			rc = ioctl(fd, VAS_TX_WIN_OPEN,
> +					(unsigned long)&txattr);
> +			if (rc < 0) {
> +				fprintf(stderr, "ioctl() n %d, error %d\n",
> +						rc, errno);
> +				return rc;
> +			}
> +			addr = mmap(NULL, 4096, PROT_READ|PROT_WRITE,
> +					MAP_SHARED, fd, 0ULL);
> +			if (addr == MAP_FAILED) {
> +				fprintf(stderr, "mmap() failed, errno %d\n",
> +						errno);
> +				return -errno;
> +			}
> +			do {
> +				//Format CRB request with compression or
> +				//uncompression
> +				// Refer tests for vas_copy/vas_paste
> +				vas_copy((&crb, 0, 1);
> +				vas_paste(addr, 0, 1);
> +				// Poll on csb.flags with timeout
> +				// csb address is listed in CRB
> +			} while (true)
> +			close(fd) or window can be closed upon process exit
> +		}
> +
> +	Refer https://github.com/abalib/power-gzip for tests or more
> +	use cases.
> -- 
> 1.8.3.1

Re: [PATCH v3 3/9] powerpc/vas: Add VAS user space API

[Haren Myneni]

On Fri, 2020-03-20 at 23:18 +1100, Daniel Axtens wrote:
> Haren Myneni <haren@linux.ibm.com> writes:
> 
> > On power9, userspace can send GZIP compression requests directly to NX
> > once kernel establishes NX channel / window with VAS. This patch provides
> > user space API which allows user space to establish channel using open
> > VAS_TX_WIN_OPEN ioctl, mmap and close operations.
> >
> > Each window corresponds to file descriptor and application can open
> > multiple windows. After the window is opened, VAS_TX_WIN_OPEN icoctl to
> > open a window on specific VAS instance, mmap() system call to map
> > the hardware address of engine's request queue into the application's
> > virtual address space.
> >
> > Then the application can then submit one or more requests to the the
> > engine by using the copy/paste instructions and pasting the CRBs to
> > the virtual address (aka paste_address) returned by mmap().
> >
> > Only NX GZIP coprocessor type is supported right now and allow GZIP
> > engine access via /dev/crypto/nx-gzip device node.
> >
> > Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
> > Signed-off-by: Haren Myneni <haren@linux.ibm.com>
> > ---
> >  arch/powerpc/include/asm/vas.h              |  11 ++
> >  arch/powerpc/platforms/powernv/Makefile     |   2 +-
> >  arch/powerpc/platforms/powernv/vas-api.c    | 290 ++++++++++++++++++++++++++++
> >  arch/powerpc/platforms/powernv/vas-window.c |   6 +-
> >  arch/powerpc/platforms/powernv/vas.h        |   2 +
> >  5 files changed, 307 insertions(+), 4 deletions(-)
> >  create mode 100644 arch/powerpc/platforms/powernv/vas-api.c
> >
> > diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
> > index f93e6b0..e064953 100644
> > --- a/arch/powerpc/include/asm/vas.h
> > +++ b/arch/powerpc/include/asm/vas.h
> > @@ -163,4 +163,15 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
> >   */
> >  int vas_paste_crb(struct vas_window *win, int offset, bool re);
> >  
> > +/*
> > + * Register / unregister coprocessor type to VAS API which will be exported
> > + * to user space. Applications can use this API to open / close window
> > + * which can be used to send / receive requests directly to cooprcessor.
> > + *
> > + * Only NX GZIP coprocessor type is supported now, but this API can be
> > + * used for others in future.
> > + */
> > +int vas_register_coproc_api(struct module *mod);
> > +void vas_unregister_coproc_api(void);
> > +
> >  #endif /* __ASM_POWERPC_VAS_H */
> > diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
> > index 395789f..fe3f0fb 100644
> > --- a/arch/powerpc/platforms/powernv/Makefile
> > +++ b/arch/powerpc/platforms/powernv/Makefile
> > @@ -17,7 +17,7 @@ obj-$(CONFIG_MEMORY_FAILURE)	+= opal-memory-errors.o
> >  obj-$(CONFIG_OPAL_PRD)	+= opal-prd.o
> >  obj-$(CONFIG_PERF_EVENTS) += opal-imc.o
> >  obj-$(CONFIG_PPC_MEMTRACE)	+= memtrace.o
> > -obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o
> > +obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o vas-api.o
> >  obj-$(CONFIG_OCXL_BASE)	+= ocxl.o
> >  obj-$(CONFIG_SCOM_DEBUGFS) += opal-xscom.o
> >  obj-$(CONFIG_PPC_SECURE_BOOT) += opal-secvar.o
> > diff --git a/arch/powerpc/platforms/powernv/vas-api.c b/arch/powerpc/platforms/powernv/vas-api.c
> > new file mode 100644
> > index 0000000..3473a4a
> > --- /dev/null
> > +++ b/arch/powerpc/platforms/powernv/vas-api.c
> > @@ -0,0 +1,290 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * VAS user space API for its accelerators (Only NX-GZIP is supported now)
> > + * Copyright (C) 2019 Haren Myneni, IBM Corp
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/device.h>
> > +#include <linux/cdev.h>
> > +#include <linux/fs.h>
> > +#include <linux/slab.h>
> > +#include <linux/uaccess.h>
> > +#include <asm/vas.h>
> > +#include <uapi/asm/vas-api.h>
> > +#include "vas.h"
> > +
> > +/*
> > + * The driver creates the device node that can be used as follows:
> > + * For NX-GZIP
> > + *
> > + *	fd = open("/dev/crypto/nx-gzip", O_RDWR);
> > + *	rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr);
> > + *	paste_addr = mmap(NULL, PAGE_SIZE, prot, MAP_SHARED, fd, 0ULL).
> > + *	vas_copy(&crb, 0, 1);
> > + *	vas_paste(paste_addr, 0, 1);
> > + *	close(fd) or exit process to close window.
> > + *
> > + * where "vas_copy" and "vas_paste" are defined in copy-paste.h.
> > + * copy/paste returns to the user space directly. So refer NX hardware
> > + * documententation for excat copy/paste usage and completion / error
> > + * conditions.
> > + */
> > +
> > +static char	*coproc_dev_name = "nx-gzip";
> > +static atomic_t	coproc_instid = ATOMIC_INIT(0);
> > +
> > +/*
> > + * Wrapper object for the nx-gzip device - there is just one instance of
> > + * this node for the whole system.
> > + */
> > +static struct coproc_dev {
> > +	struct cdev cdev;
> > +	struct device *device;
> > +	char *name;
> > +	dev_t devt;
> > +	struct class *class;
> > +} coproc_device;
> > +
> > +/*
> > + * One instance per open of a nx-gzip device. Each coproc_instance is
> > + * associated with a VAS window after the caller issues
> > + * VAS_GZIP_TX_WIN_OPEN ioctl.
> > + */
> > +struct coproc_instance {
> > +	int id;
> > +	struct vas_window *txwin;
> > +};
> > +
> > +static char *coproc_devnode(struct device *dev, umode_t *mode)
> > +{
> > +	return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev));
> > +}
> > +
> > +static int coproc_open(struct inode *inode, struct file *fp)
> > +{
> > +	struct coproc_instance *instance;
> > +
> > +	instance = kzalloc(sizeof(*instance), GFP_KERNEL);
> > +	if (!instance)
> > +		return -ENOMEM;
> > +
> > +	instance->id = atomic_inc_return(&coproc_instid);
> 
> I don't understand what this instance->id field does - I can't find any
> other uses of it in these series.
> 
> I'm also not sure that this gives you a unique id - you increment it
> here and decrement it in coproc_release, but I'm not sure what prevents
> the same ID being given to multiple instances, e.g. the following
> sequence
> 
> coproc_open(inode,    file A) -> instance with id 0, coproc_instid = 1
> coproc_open(inode,    file B) -> instance with id 1, coproc_instid = 2
> coproc_release(inode, file A) -> release id 0, coproc_instid = 1
> coproc_open(inode,    file C) -> instance with id 1, coproc_instid = 2
> 
> File B and C both have ID = 1, unless I'm misunderstanding something.

Thanks for your comments. 

coproc_instid is not needed. Sorry My mistake, it was added in prototype
code, but forgot to remove. Added to determine how many windows are
active, but not needed now. 

I will repost the patch with this change.

> 
> > +
> > +	fp->private_data = instance;
> > +	return 0;
> > +}
> > +
> > +static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
> > +{
> > +	int rc, vasid;
> > +	struct vas_tx_win_attr txattr;
> > +	struct vas_tx_win_open_attr uattr;
> > +	void __user *uptr = (void __user *)arg;
> > +	struct vas_window *txwin;
> > +	struct coproc_instance *nxti = fp->private_data;
> > +
> > +	if (!nxti)
> > +		return -EINVAL;
> > +
> > +	/*
> > +	 * One window for file descriptor
> > +	 */
> > +	if (nxti->txwin)
> > +		return -EEXIST;
> > +
> > +	rc = copy_from_user(&uattr, uptr, sizeof(uattr));
> > +	if (rc) {
> > +		pr_err("%s(): copy_from_user() returns %d\n", __func__, rc);
> > +		return -EFAULT;
> > +	}
> > +
> > +	if (uattr.version != 1) {
> > +		pr_err("Invalid version\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	vasid = uattr.vas_id;
> > +
> > +	memset(&txattr, 0, sizeof(struct vas_tx_win_attr));
> 
> You could define txattr with `struct vas_tx_win_attr txattr = {};` and
> avoid the explicit memset.
> 
> > +	vas_init_tx_win_attr(&txattr, VAS_COP_TYPE_GZIP);
> > +
> > +	txattr.lpid = mfspr(SPRN_LPID);
> > +	txattr.pidr = mfspr(SPRN_PID);
> > +	txattr.user_win = true;
> > +	txattr.rsvd_txbuf_count = false;
> > +	txattr.pswid = false;
> > +	/*
> > +	 * txattr.wcreds_max is set to VAS_WCREDS_DEFAULT (1024) in
> > +	 * vas-window.c, but can be changed specific to GZIP depends
> > +	 * on user space need.
> > +	 * If needed to set txattr.wcreds_max here.
> > +	 */
> 
> Who could set this? You mention userspace need but it looks like the
> user cannot set this. Is this a message to future kernel developers?

set the default value in vax_tx_win_open() (vas_window.c) if it is not
set here. credits limit can set here if we decide to use non-default
value for user space windows. Not allowing user space to set this value.
Yes, this comment is for kernel developers. 

I can remove this comment to remove the confusion.  

> 
> > +
> > +	pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
> > +				mfspr(SPRN_PID));
> > +
> > +	txwin = vas_tx_win_open(vasid, VAS_COP_TYPE_GZIP, &txattr);
> > +	if (IS_ERR(txwin)) {
> > +		pr_err("%s() vas_tx_win_open() failed, %ld\n", __func__,
> > +					PTR_ERR(txwin));
> > +		return PTR_ERR(txwin);
> > +	}
> > +
> > +	nxti->txwin = txwin;
> > +
> > +	return 0;
> > +}
> > +
> > +static int coproc_release(struct inode *inode, struct file *fp)
> > +{
> > +	struct coproc_instance *instance;
> > +
> > +	instance = fp->private_data;
> > +
> > +	if (instance && instance->txwin) {
> > +		vas_win_close(instance->txwin);
> > +		instance->txwin = NULL;
> > +	}
> > +
> > +	/*
> > +	 * We don't know here if user has other receive windows
> > +	 * open, so we can't really call clear_thread_tidr().
> > +	 * So, once the process calls set_thread_tidr(), the
> > +	 * TIDR value sticks around until process exits, resulting
> > +	 * in an extra copy in restore_sprs().
> > +	 */
> > +
> > +	kfree(instance);
> > +	fp->private_data = NULL;
> > +	atomic_dec(&coproc_instid);
> > +
> > +	return 0;
> > +}
> > +
> > +static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
> > +{
> > +	int rc;
> > +	pgprot_t prot;
> > +	u64 paste_addr;
> > +	unsigned long pfn;
> > +	struct coproc_instance *instance = fp->private_data;
> > +
> > +	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
> > +		pr_debug("%s(): size 0x%zx, PAGE_SIZE 0x%zx\n", __func__,
> > +				(vma->vm_end - vma->vm_start), PAGE_SIZE);
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* Ensure instance has an open send window */
> > +	if (!instance->txwin) {
> > +		pr_err("%s(): No send window open?\n", __func__);
> > +		return -EINVAL;
> > +	}
> > +
> > +	vas_win_paste_addr(instance->txwin, &paste_addr, NULL);
> > +	pfn = paste_addr >> PAGE_SHIFT;
> > +
> > +	/* flags, page_prot from cxl_mmap(), except we want cachable */
> > +	vma->vm_flags |= VM_IO | VM_PFNMAP;
> > +	vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
> > +
> > +	prot = __pgprot(pgprot_val(vma->vm_page_prot) | _PAGE_DIRTY);
> > +
> > +	rc = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
> > +			vma->vm_end - vma->vm_start, prot);
> > +
> > +	pr_devel("%s(): paste addr %llx at %lx, rc %d\n", __func__,
> > +			paste_addr, vma->vm_start, rc);
> > +
> > +	return rc;
> > +}
> > +
> > +static long coproc_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
> > +{
> > +	switch (cmd) {
> > +	case VAS_TX_WIN_OPEN:
> > +		return coproc_ioc_tx_win_open(fp, arg);
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +}
> > +
> > +static struct file_operations coproc_fops = {
> > +	.open = coproc_open,
> > +	.release = coproc_release,
> > +	.mmap = coproc_mmap,
> > +	.unlocked_ioctl = coproc_ioctl,
> > +};
> > +
> > +/*
> > + * Supporting only nx-gzip coprocessor type now, but this API code
> > + * extended to other coprocessor types later.
> > + */
> > +int vas_register_coproc_api(struct module *mod)
> > +{
> > +	int rc = -EINVAL;
> > +	dev_t devno;
> > +
> > +	rc = alloc_chrdev_region(&coproc_device.devt, 1, 1, "nx-gzip");
> > +	if (rc) {
> > +		pr_err("Unable to allocate coproc major number: %i\n", rc);
> > +		return rc;
> > +	}
> > +
> > +	pr_devel("NX-GZIP device allocated, dev [%i,%i]\n",
> > +			MAJOR(coproc_device.devt), MINOR(coproc_device.devt));
> > +
> > +	coproc_device.class = class_create(mod, "nx-gzip");
> > +	if (IS_ERR(coproc_device.class)) {
> > +		rc = PTR_ERR(coproc_device.class);
> > +		pr_err("Unable to create NX-GZIP class %d\n", rc);
> > +		goto err_class;
> > +	}
> > +	coproc_device.class->devnode = coproc_devnode;
> > +
> > +	coproc_fops.owner = mod;
> > +	cdev_init(&coproc_device.cdev, &coproc_fops);
> 
> Looking into this coproc_fops thing more:
> 
> I find this API very confusing. The comment at the top of the function
> says it will be extended, but there's only one coproc_fops, so currently
> it can only be instantiated once and owned by one module. Much of the
> rest of that function is also very much based around the nx-gzip
> coprocessor.
> 
> I'm not fully certain about how this should work, but I think probably
> it either needs to be fully generic or fully nx-gzip only for now. I
> would make it fully nx-gzip only and extend it later, but I'm not fussy.

We are adding only for NX-GZIP right now and mentioned nx-gzip. Most of
interfaces in coproc_fops such as open/mmap/close should be common for
any coprocs except ioctl or new ioctl cmd. 

register_coproc_api creates device node and register fs API specific to
coprocessor. user space use fs API to establish communication channel
(using open, ioctl, mmap) to NX.

How about defining coproc_nxgzip_fs to remove this confusion. 

> 
> > +
> > +	devno = MKDEV(MAJOR(coproc_device.devt), 0);
> > +	rc = cdev_add(&coproc_device.cdev, devno, 1);
> > +	if (rc) {
> > +		pr_err("cdev_add() failed %d\n", rc);
> > +		goto err_cdev;
> > +	}
> > +
> > +	coproc_device.device = device_create(coproc_device.class, NULL,
> > +			devno, NULL, coproc_dev_name, MINOR(devno));
> > +	if (IS_ERR(coproc_device.device)) {
> > +		rc = PTR_ERR(coproc_device.device);
> > +		pr_err("Unable to create coproc-%d %d\n", MINOR(devno), rc);
> > +		goto err;
> > +	}
> > +
> > +	pr_devel("%s: Added dev [%d,%d]\n", __func__, MAJOR(devno),
> > +			MINOR(devno));
> > +
> > +	return 0;
> > +
> > +err:
> > +	cdev_del(&coproc_device.cdev);
> > +err_cdev:
> > +	class_destroy(coproc_device.class);
> > +err_class:
> > +	unregister_chrdev_region(coproc_device.devt, 1);
> > +	return rc;
> > +}
> > +EXPORT_SYMBOL_GPL(vas_register_coproc_api);
> > +
> > +void vas_unregister_coproc_api(void)
> > +{
> > +	dev_t devno;
> > +
> > +	cdev_del(&coproc_device.cdev);
> > +	devno = MKDEV(MAJOR(coproc_device.devt), 0);
> > +	device_destroy(coproc_device.class, devno);
> > +
> > +	class_destroy(coproc_device.class);
> > +	unregister_chrdev_region(coproc_device.devt, 1);
> > +}
> > +EXPORT_SYMBOL_GPL(vas_unregister_coproc_api);
> > diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
> > index e9ab851..7484296 100644
> > --- a/arch/powerpc/platforms/powernv/vas-window.c
> > +++ b/arch/powerpc/platforms/powernv/vas-window.c
> > @@ -26,7 +26,7 @@
> >   * Compute the paste address region for the window @window using the
> >   * ->paste_base_addr and ->paste_win_id_shift we got from device tree.
> >   */
> > -static void compute_paste_address(struct vas_window *window, u64 *addr, int *len)
> > +void vas_win_paste_addr(struct vas_window *window, u64 *addr, int *len)
> >  {
> >  	int winid;
> >  	u64 base, shift;
> > @@ -80,7 +80,7 @@ static void *map_paste_region(struct vas_window *txwin)
> >  		goto free_name;
> >  
> >  	txwin->paste_addr_name = name;
> > -	compute_paste_address(txwin, &start, &len);
> > +	vas_win_paste_addr(txwin, &start, &len);
> >  
> >  	if (!request_mem_region(start, len, name)) {
> >  		pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
> > @@ -138,7 +138,7 @@ static void unmap_paste_region(struct vas_window *window)
> >  	u64 busaddr_start;
> >  
> >  	if (window->paste_kaddr) {
> > -		compute_paste_address(window, &busaddr_start, &len);
> > +		vas_win_paste_addr(window, &busaddr_start, &len);
> >  		unmap_region(window->paste_kaddr, busaddr_start, len);
> >  		window->paste_kaddr = NULL;
> >  		kfree(window->paste_addr_name);
> > diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
> > index 8c39a7d..a10abed 100644
> > --- a/arch/powerpc/platforms/powernv/vas.h
> > +++ b/arch/powerpc/platforms/powernv/vas.h
> > @@ -431,6 +431,8 @@ struct vas_winctx {
> >  extern void vas_return_credit(struct vas_window *window, bool tx);
> >  extern struct vas_window *vas_pswid_to_window(struct vas_instance *vinst,
> >  						uint32_t pswid);
> > +extern void vas_win_paste_addr(struct vas_window *window, u64 *addr,
> > +					int *len);
> >  
> >  static inline int vas_window_pid(struct vas_window *window)
> >  {
> > -- 
> > 1.8.3.1

Re: [PATCH v3 9/9] Documentation/powerpc: VAS API

[Haren Myneni]

On Fri, 2020-03-20 at 23:24 +1100, Daniel Axtens wrote:
> Hi Haren,
> 
> This is good documentation.
> 
> > Power9 introduced Virtual Accelerator Switchboard (VAS) which allows
> > userspace to communicate with Nest Accelerator (NX) directly. But
> > kernel has to establish channel to NX for userspace. This document
> > describes user space API that application can use to establish
> > communication channel.
> >
> > Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
> > Signed-off-by: Haren Myneni <haren@linux.ibm.com>
> > ---
> >  Documentation/powerpc/index.rst   |   1 +
> >  Documentation/powerpc/vas-api.rst | 246 ++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 247 insertions(+)
> >  create mode 100644 Documentation/powerpc/vas-api.rst
> >
> > diff --git a/Documentation/powerpc/index.rst b/Documentation/powerpc/index.rst
> > index 0d45f0f..afe2d5e 100644
> > --- a/Documentation/powerpc/index.rst
> > +++ b/Documentation/powerpc/index.rst
> > @@ -30,6 +30,7 @@ powerpc
> >      syscall64-abi
> >      transactional_memory
> >      ultravisor
> > +    vas-api
> >  
> >  .. only::  subproject and html
> >  
> > diff --git a/Documentation/powerpc/vas-api.rst b/Documentation/powerpc/vas-api.rst
> > new file mode 100644
> > index 0000000..13ce4e7
> > --- /dev/null
> > +++ b/Documentation/powerpc/vas-api.rst
> > @@ -0,0 +1,246 @@
> > +.. SPDX-License-Identifier: GPL-2.0
> > +.. _VAS-API:
> > +
> > +===================================================
> > +Virtual Accelerator Switchboard (VAS) userspace API
> > +===================================================
> > +
> > +Introduction
> > +============
> > +
> > +Power9 processor introduced Virtual Accelerator Switchboard (VAS) which
> > +allows both userspace and kernel communicate to co-processor
> > +(hardware accelerator) referred to as the Nest Accelerator (NX). The NX
> > +unit comprises of one or more hardware engines or co-processor types
> > +such as 842 compression, GZIP compression and encryption. On power9,
> > +userspace applications will have access to only GZIP Compression engine
> > +which supports ZLIB and GZIP compression algorithms in the hardware.
> > +
> > +To communicate with NX, kernel has to establish a channel or window and
> > +then requests can be submitted directly without kernel involvement.
> > +Requests to the GZIP engine must be formatted as a co-processor Request
> > +Block (CRB) and these CRBs must be submitted to the NX using COPY/PASTE
> > +instructions to paste the CRB to hardware address that is associated with
> > +the engine's request queue.
> > +
> > +The GZIP engine provides two priority levels of requests: Normal and
> > +High. Only Normal requests are supported from userspace right now.
> > +
> > +This document explains userspace API that is used to interact with
> > +kernel to setup channel / window which can be used to send compression
> > +requests directly to NX accelerator.
> > +
> > +
> > +Overview
> > +========
> > +
> > +Application access to the GZIP engine is provided through
> > +/dev/crypto/nx-gzip device node implemented by the VAS/NX device driver.
> > +An application must open the /dev/crypto/nx-gzip device to obtain a file
> > +descriptor (fd). Then should issue VAS_TX_WIN_OPEN ioctl with this fd to
> > +establish connection to the engine. It means send window is opened on GZIP
> > +engine for this process. Once a connection is established, the application
> > +should use the mmap() system call to map the hardware address of engine's
> > +request queue into the application's virtual address space.
> > +
> > +The application can then submit one or more requests to the the engine by
> > +using copy/paste instructions and pasting the CRBs to the virtual address
> > +(aka paste_address) returned by mmap(). User space can close the
> > +established connection or send window by closing the file descriptior
> > +(close(fd)) or upon the process exit.
> > +
> > +Note that applications can send several requests with the same window or
> > +can establish multiple windows, but one window for each file descriptor.
> > +
> > +Following sections provide additional details and references about the
> > +individual steps.
> > +
> > +NX-GZIP Device Node
> > +===================
> > +
> > +There is one /dev/crypto/nx-gzip node in the system and it provides
> > +access to all GZIP engines in the system. The only valid operations on
> > +/dev/crypto/nx-gzip are:
> > +
> > +	* open() the device for read and write.
> > +	* issue VAS_TX_WIN_OPEN ioctl
> > +	* mmap() the engine's request queue into application's virtual
> > +	  address space (i.e. get a paste_address for the co-processor
> > +	  engine).
> > +	* close the device node.
> > +
> > +Other file operations on this device node are undefined.
> > +
> > +Note that the copy and paste operations go directly to the hardware and
> > +do not go through this device. Refer COPY/PASTE document for more
> > +details.
> > +
> > +Although a system may have several instances of the NX co-processor
> > +engines (typically, one per P9 chip) there is just one
> > +/dev/crypto/nx-gzip device node in the system. When the nx-gzip device
> > +node is opened, Kernel opens send window on a suitable instance of NX
> > +accelerator. It finds CPU on which the user process is executing and
> > +determine the NX instance for the corresponding chip on which this CPU
> > +belongs.
> > +
> > +Applications may chose a specific instance of the NX co-processor using
> > +the vas_id field in the VAS_TX_WIN_OPEN ioctl as detailed below.
> > +
> > +A userspace library libnxz is available here but still in development:
> > +	 https://github.com/abalib/power-gzip
> > +
> > +Applications that use inflate / deflate calls can link with libnxz
> > +instead of libz and use NX GZIP compression without any modification.
> > +
> > +Open /dev/crypto/nx-gzip
> > +========================
> > +
> > +The nx-gzip device should be opened for read and write. No special
> > +privileges are needed to open the device. Each window coreesponds to one
> 
> s/coreesponds/corresponds/
> 
> > +file descriptor. So if the userspace process needs multiple windows,
> > +several open calls have to be issued.
> > +
> > +See open(2) system call man pages for other details such as return values,
> > +error codes and restrictions.
> > +codes and restrictions.
> 
> You have 'codes and restrictions' twice here.
> 
> > +
> > +VAS_TX_WIN_OPEN ioctl
> > +=====================
> > +
> > +Applications should use the VAS_TX_WIN_OPEN ioctl as follows to establish
> > +a connection with NX co-processor engine:
> > +
> > +	::
> > +		struct vas_tx_win_open_attr {
> > +			__u32   version;
> > +			__s16   vas_id; /* specific instance of vas or -1
> > +						for default */
> > +			__u16   reserved1;
> > +			__u64   flags;	/* For future use */
> > +			__u64   reserved2[6];
> > +		};
> > +
> > +	version: The version field must be currently set to 1.
> > +	vas_id: If '-1' is passed, kernel will make a best-effort attempt
> > +		to assign an optimal instance of NX for the process. To
> > +		select the specific VAS instance, refer
> > +		"Discovery of available VAS engines" section below.
> > +
> > +	flags, reserved1 and reserved2[6] fields are for future extension
> > +	and must be set to 0.
> > +
> > +	The attributes attr for the VAS_TX_WIN_OPEN ioctl are defined as
> > +	follows:
> > +		#define VAS_MAGIC 'v'
> > +		#define VAS_TX_WIN_OPEN _IOW(VAS_MAGIC, 1,
> > +						struct vas_tx_win_open_attr)
> > +
> > +		struct vas_tx_win_open_attr attr;
> > +		rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr);
> > +
> > +	The VAS_TX_WIN_OPEN ioctl returns 0 on success. On errors, it
> > +	returns -1 and sets the errno variable to indicate the error.
> > +
> > +	Error conditions:
> > +		EINVAL	fd does not refer to a valid VAS device.
> > +		EINVAL	Invalid vas ID
> > +		EINVAL	version is not set with proper value
> > +		EEXIST	Window is already opened for the given fd
> > +		ENOMEM	Memory is not available to allocate window
> > +		ENOSPC	System has too many active windows (connections)
> > +			opened
> > +		EINVAL	reserved fields are not set to 0.
> > +
> > +	See the ioctl(2) man page for more details, error codes and
> > +	restrictions.
> > +
> > +mmap() NX-GZIP device
> > +=====================
> > +
> > +The mmap() system call for a NX-GZIP device fd returns a paste_address
> > +that the application can use to copy/paste its CRB to the hardware engines.
> > +	::
> > +
> > +		paste_addr = mmap(addr, size, prot, flags, fd, offset);
> > +
> > +	Only restrictions on mmap for a NX-GZIP device fd are:
> > +		* size should be 4K page size
> 
> Patch 3 seems to allow a 64k page if the system is compiled for 64k
> pages... Should it restrict it to 4K?
Yes restricted to 4K for NX-GZIP

Re: [PATCH v3 9/9] Documentation/powerpc: VAS API

[Nicholas Piggin]

Haren Myneni's on March 7, 2020 10:39 am:
> 
> Power9 introduced Virtual Accelerator Switchboard (VAS) which allows
> userspace to communicate with Nest Accelerator (NX) directly. But
> kernel has to establish channel to NX for userspace. This document
> describes user space API that application can use to establish
> communication channel.

Agree with Daniel this is good documentation.

But I don't see mention of the word 'signal' anywhere. The signal stuff
is one of the trickiest parts this code being added. It would be great if
that could be documented and even with example code or at least a
description of why it's required and can't be done some other way.

Does something like io_uring require signals in such cases?

Thanks,
Nick

[PATCH V3 3/9] powerpc/vas: Add VAS user space API

[Haren Myneni]

On power9, userspace can send GZIP compression requests directly to NX
once kernel establishes NX channel / window with VAS. This patch provides
user space API which allows user space to establish channel using open
VAS_TX_WIN_OPEN ioctl, mmap and close operations.

Each window corresponds to file descriptor and application can open
multiple windows. After the window is opened, VAS_TX_WIN_OPEN icoctl to
open a window on specific VAS instance, mmap() system call to map
the hardware address of engine's request queue into the application's
virtual address space.

Then the application can then submit one or more requests to the the
engine by using the copy/paste instructions and pasting the CRBs to
the virtual address (aka paste_address) returned by mmap().

Only NX GZIP coprocessor type is supported right now and allow GZIP
engine access via /dev/crypto/nx-gzip device node.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 arch/powerpc/include/asm/vas.h              |  11 ++
 arch/powerpc/platforms/powernv/Makefile     |   2 +-
 arch/powerpc/platforms/powernv/vas-api.c    | 290 ++++++++++++++++++++++++++++
 arch/powerpc/platforms/powernv/vas-window.c |   6 +-
 arch/powerpc/platforms/powernv/vas.h        |   2 +
 5 files changed, 307 insertions(+), 4 deletions(-)
 create mode 100644 arch/powerpc/platforms/powernv/vas-api.c

diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index f93e6b0..e064953 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h
@@ -163,4 +163,15 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
  */
 int vas_paste_crb(struct vas_window *win, int offset, bool re);
 
+/*
+ * Register / unregister coprocessor type to VAS API which will be exported
+ * to user space. Applications can use this API to open / close window
+ * which can be used to send / receive requests directly to cooprcessor.
+ *
+ * Only NX GZIP coprocessor type is supported now, but this API can be
+ * used for others in future.
+ */
+int vas_register_coproc_api(struct module *mod);
+void vas_unregister_coproc_api(void);
+
 #endif /* __ASM_POWERPC_VAS_H */
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index 395789f..fe3f0fb 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -17,7 +17,7 @@ obj-$(CONFIG_MEMORY_FAILURE)	+= opal-memory-errors.o
 obj-$(CONFIG_OPAL_PRD)	+= opal-prd.o
 obj-$(CONFIG_PERF_EVENTS) += opal-imc.o
 obj-$(CONFIG_PPC_MEMTRACE)	+= memtrace.o
-obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o
+obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o vas-api.o
 obj-$(CONFIG_OCXL_BASE)	+= ocxl.o
 obj-$(CONFIG_SCOM_DEBUGFS) += opal-xscom.o
 obj-$(CONFIG_PPC_SECURE_BOOT) += opal-secvar.o
diff --git a/arch/powerpc/platforms/powernv/vas-api.c b/arch/powerpc/platforms/powernv/vas-api.c
new file mode 100644
index 0000000..d72755c
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/vas-api.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * VAS user space API for its accelerators (Only NX-GZIP is supported now)
+ * Copyright (C) 2019 Haren Myneni, IBM Corp
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <asm/vas.h>
+#include <uapi/asm/vas-api.h>
+#include "vas.h"
+
+/*
+ * The driver creates the device node that can be used as follows:
+ * For NX-GZIP
+ *
+ *	fd = open("/dev/crypto/nx-gzip", O_RDWR);
+ *	rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr);
+ *	paste_addr = mmap(NULL, PAGE_SIZE, prot, MAP_SHARED, fd, 0ULL).
+ *	vas_copy(&crb, 0, 1);
+ *	vas_paste(paste_addr, 0, 1);
+ *	close(fd) or exit process to close window.
+ *
+ * where "vas_copy" and "vas_paste" are defined in copy-paste.h.
+ * copy/paste returns to the user space directly. So refer NX hardware
+ * documententation for excat copy/paste usage and completion / error
+ * conditions.
+ */
+
+static char	*coproc_dev_name = "nx-gzip";
+static atomic_t	coproc_instid = ATOMIC_INIT(0);
+
+/*
+ * Wrapper object for the nx-gzip device - there is just one instance of
+ * this node for the whole system.
+ */
+struct coproc_dev {
+	struct cdev cdev;
+	struct device *device;
+	char *name;
+	dev_t devt;
+	struct class *class;
+} coproc_device;
+
+/*
+ * One instance per open of a nx-gzip device. Each coproc_instance is
+ * associated with a VAS window after the caller issues
+ * VAS_GZIP_TX_WIN_OPEN ioctl.
+ */
+struct coproc_instance {
+	int id;
+	struct vas_window *txwin;
+};
+
+static char *coproc_devnode(struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev));
+}
+
+static int coproc_open(struct inode *inode, struct file *fp)
+{
+	struct coproc_instance *instance;
+
+	instance = kzalloc(sizeof(*instance), GFP_KERNEL);
+	if (!instance)
+		return -ENOMEM;
+
+	instance->id = atomic_inc_return(&coproc_instid);
+
+	fp->private_data = instance;
+	return 0;
+}
+
+static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
+{
+	int rc, vasid;
+	struct vas_tx_win_attr txattr;
+	struct vas_tx_win_open_attr uattr;
+	void __user *uptr = (void *)arg;
+	struct vas_window *txwin;
+	struct coproc_instance *nxti = fp->private_data;
+
+	if (!nxti)
+		return -EINVAL;
+
+	/*
+	 * One window for file descriptor
+	 */
+	if (nxti->txwin)
+		return -EEXIST;
+
+	rc = copy_from_user(&uattr, uptr, sizeof(uattr));
+	if (rc) {
+		pr_err("%s(): copy_from_user() returns %d\n", __func__, rc);
+		return -EFAULT;
+	}
+
+	if (uattr.version != 1) {
+		pr_err("Invalid version\n");
+		return -EINVAL;
+	}
+
+	vasid = uattr.vas_id;
+
+	memset(&txattr, 0, sizeof(struct vas_tx_win_attr));
+	vas_init_tx_win_attr(&txattr, VAS_COP_TYPE_GZIP);
+
+	txattr.lpid = mfspr(SPRN_LPID);
+	txattr.pidr = mfspr(SPRN_PID);
+	txattr.user_win = true;
+	txattr.rsvd_txbuf_count = false;
+	txattr.pswid = false;
+	/*
+	 * txattr.wcreds_max is set to VAS_WCREDS_DEFAULT (1024) in
+	 * vas-window.c, but can be changed specific to GZIP depends
+	 * on user space need.
+	 * If needed to set txattr.wcreds_max here.
+	 */
+
+	pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
+				mfspr(SPRN_PID));
+
+	txwin = vas_tx_win_open(vasid, VAS_COP_TYPE_GZIP, &txattr);
+	if (IS_ERR(txwin)) {
+		pr_err("%s() vas_tx_win_open() failed, %ld\n", __func__,
+					PTR_ERR(txwin));
+		return PTR_ERR(txwin);
+	}
+
+	nxti->txwin = txwin;
+
+	return 0;
+}
+
+static int coproc_release(struct inode *inode, struct file *fp)
+{
+	struct coproc_instance *instance;
+
+	instance = fp->private_data;
+
+	if (instance && instance->txwin) {
+		vas_win_close(instance->txwin);
+		instance->txwin = NULL;
+	}
+
+	/*
+	 * We don't know here if user has other receive windows
+	 * open, so we can't really call clear_thread_tidr().
+	 * So, once the process calls set_thread_tidr(), the
+	 * TIDR value sticks around until process exits, resulting
+	 * in an extra copy in restore_sprs().
+	 */
+
+	kfree(instance);
+	fp->private_data = NULL;
+	atomic_dec(&coproc_instid);
+
+	return 0;
+}
+
+static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
+{
+	int rc;
+	pgprot_t prot;
+	u64 paste_addr;
+	unsigned long pfn;
+	struct coproc_instance *instance = fp->private_data;
+
+	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
+		pr_debug("%s(): size 0x%zx, PAGE_SIZE 0x%zx\n", __func__,
+				(vma->vm_end - vma->vm_start), PAGE_SIZE);
+		return -EINVAL;
+	}
+
+	/* Ensure instance has an open send window */
+	if (!instance->txwin) {
+		pr_err("%s(): No send window open?\n", __func__);
+		return -EINVAL;
+	}
+
+	vas_win_paste_addr(instance->txwin, &paste_addr, NULL);
+	pfn = paste_addr >> PAGE_SHIFT;
+
+	/* flags, page_prot from cxl_mmap(), except we want cachable */
+	vma->vm_flags |= VM_IO | VM_PFNMAP;
+	vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
+
+	prot = __pgprot(pgprot_val(vma->vm_page_prot) | _PAGE_DIRTY);
+
+	rc = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
+			vma->vm_end - vma->vm_start, prot);
+
+	pr_devel("%s(): paste addr %llx at %lx, rc %d\n", __func__,
+			paste_addr, vma->vm_start, rc);
+
+	return rc;
+}
+
+static long coproc_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case VAS_TX_WIN_OPEN:
+		return coproc_ioc_tx_win_open(fp, arg);
+	default:
+		return -EINVAL;
+	}
+}
+
+struct file_operations coproc_fops = {
+	.open = coproc_open,
+	.release = coproc_release,
+	.mmap = coproc_mmap,
+	.unlocked_ioctl = coproc_ioctl,
+};
+
+/*
+ * Supporting only nx-gzip coprocessor type now, but this API code
+ * extended to other coprocessor types later.
+ */
+int vas_register_coproc_api(struct module *mod)
+{
+	int rc = -EINVAL;
+	dev_t devno;
+
+	rc = alloc_chrdev_region(&coproc_device.devt, 1, 1, "nx-gzip");
+	if (rc) {
+		pr_err("Unable to allocate coproc major number: %i\n", rc);
+		return rc;
+	}
+
+	pr_devel("NX-GZIP device allocated, dev [%i,%i]\n",
+			MAJOR(coproc_device.devt), MINOR(coproc_device.devt));
+
+	coproc_device.class = class_create(mod, "nx-gzip");
+	if (IS_ERR(coproc_device.class)) {
+		rc = PTR_ERR(coproc_device.class);
+		pr_err("Unable to create NX-GZIP class %d\n", rc);
+		goto err_class;
+	}
+	coproc_device.class->devnode = coproc_devnode;
+
+	coproc_fops.owner = mod;
+	cdev_init(&coproc_device.cdev, &coproc_fops);
+
+	devno = MKDEV(MAJOR(coproc_device.devt), 0);
+	rc = cdev_add(&coproc_device.cdev, devno, 1);
+	if (rc) {
+		pr_err("cdev_add() failed %d\n", rc);
+		goto err_cdev;
+	}
+
+	coproc_device.device = device_create(coproc_device.class, NULL,
+			devno, NULL, coproc_dev_name, MINOR(devno));
+	if (IS_ERR(coproc_device.device)) {
+		rc = PTR_ERR(coproc_device.device);
+		pr_err("Unable to create coproc-%d %d\n", MINOR(devno), rc);
+		goto err;
+	}
+
+	pr_devel("%s: Added dev [%d,%d]\n", __func__, MAJOR(devno),
+			MINOR(devno));
+
+	return 0;
+
+err:
+	cdev_del(&coproc_device.cdev);
+err_cdev:
+	class_destroy(coproc_device.class);
+err_class:
+	unregister_chrdev_region(coproc_device.devt, 1);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(vas_register_coproc_api);
+
+void vas_unregister_coproc_api(void)
+{
+	dev_t devno;
+
+	cdev_del(&coproc_device.cdev);
+	devno = MKDEV(MAJOR(coproc_device.devt), 0);
+	device_destroy(coproc_device.class, devno);
+
+	class_destroy(coproc_device.class);
+	unregister_chrdev_region(coproc_device.devt, 1);
+}
+EXPORT_SYMBOL_GPL(vas_unregister_coproc_api);
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index b6572af..d4a575e 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -26,7 +26,7 @@
  * Compute the paste address region for the window @window using the
  * ->paste_base_addr and ->paste_win_id_shift we got from device tree.
  */
-static void compute_paste_address(struct vas_window *window, u64 *addr, int *len)
+void vas_win_paste_addr(struct vas_window *window, u64 *addr, int *len)
 {
 	int winid;
 	u64 base, shift;
@@ -80,7 +80,7 @@ static void *map_paste_region(struct vas_window *txwin)
 		goto free_name;
 
 	txwin->paste_addr_name = name;
-	compute_paste_address(txwin, &start, &len);
+	vas_win_paste_addr(txwin, &start, &len);
 
 	if (!request_mem_region(start, len, name)) {
 		pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
@@ -138,7 +138,7 @@ static void unmap_paste_region(struct vas_window *window)
 	u64 busaddr_start;
 
 	if (window->paste_kaddr) {
-		compute_paste_address(window, &busaddr_start, &len);
+		vas_win_paste_addr(window, &busaddr_start, &len);
 		unmap_region(window->paste_kaddr, busaddr_start, len);
 		window->paste_kaddr = NULL;
 		kfree(window->paste_addr_name);
diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
index 495937a..96efb99 100644
--- a/arch/powerpc/platforms/powernv/vas.h
+++ b/arch/powerpc/platforms/powernv/vas.h
@@ -418,6 +418,8 @@ struct vas_winctx {
 extern void vas_return_credit(struct vas_window *window, bool tx);
 extern struct vas_window *vas_pswid_to_window(struct vas_instance *vinst,
 						uint32_t pswid);
+extern void vas_win_paste_addr(struct vas_window *window, u64 *addr,
+					int *len);
 
 static inline int vas_window_pid(struct vas_window *window)
 {
-- 
1.8.3.1