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From: Haren Myneni <haren@linux.ibm.com>
To: mpe@ellerman.id.au
Cc: hch@infradead.org, mikey@neuling.org, npiggin@gmail.com,
	herbert@gondor.apana.org.au, linuxppc-dev@lists.ozlabs.org,
	devicetree@vger.kernel.org, sukadev@linux.vnet.ibm.com
Subject: [PATCH V2 04/13] powerpc/vas: Setup fault window per VAS instance
Date: Sun, 08 Dec 2019 19:30:33 -0800	[thread overview]
Message-ID: <1575862233.16318.21.camel@hbabu-laptop> (raw)
In-Reply-To: <1575861522.16318.9.camel@hbabu-laptop>


Setup fault window for each VAS instance. When NX gets fault on request
buffer, write fault CRBs in the corresponding fault FIFO and then sends
an interrupt to the OS.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Haren Myneni <haren@us.ibm.com>
---
 arch/powerpc/platforms/powernv/Makefile     |  2 +-
 arch/powerpc/platforms/powernv/vas-fault.c  | 73 +++++++++++++++++++++++++++++
 arch/powerpc/platforms/powernv/vas-window.c |  3 +-
 arch/powerpc/platforms/powernv/vas.c        | 24 ++++++++++
 arch/powerpc/platforms/powernv/vas.h        |  5 ++
 5 files changed, 105 insertions(+), 2 deletions(-)
 create mode 100644 arch/powerpc/platforms/powernv/vas-fault.c

diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index a3ac964..74c2246 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -17,6 +17,6 @@ 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-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o
+obj-$(CONFIG_PPC_VAS)	+= vas.o vas-window.o vas-debug.o vas-fault.o
 obj-$(CONFIG_OCXL_BASE)	+= ocxl.o
 obj-$(CONFIG_SCOM_DEBUGFS) += opal-xscom.o
diff --git a/arch/powerpc/platforms/powernv/vas-fault.c b/arch/powerpc/platforms/powernv/vas-fault.c
new file mode 100644
index 0000000..b0258ed
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/vas-fault.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * VAS Fault handling.
+ * Copyright 2019, IBM Corporation
+ */
+
+#define pr_fmt(fmt) "vas: " fmt
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/kthread.h>
+#include <asm/icswx.h>
+
+#include "vas.h"
+
+/*
+ * The maximum FIFO size for fault window can be 8MB
+ * (VAS_RX_FIFO_SIZE_MAX). Using 4MB FIFO since each VAS
+ * instance will be having fault window.
+ * 8MB FIFO can be used if expects more faults for each VAS
+ * instance.
+ */
+#define VAS_FAULT_WIN_FIFO_SIZE	(4 << 20)
+
+/*
+ * Fault window is opened per VAS instance. NX pastes fault CRB in fault
+ * FIFO upon page faults.
+ */
+int vas_setup_fault_window(struct vas_instance *vinst)
+{
+	struct vas_rx_win_attr attr;
+
+	vinst->fault_fifo_size = VAS_FAULT_WIN_FIFO_SIZE;
+	vinst->fault_fifo = kzalloc(vinst->fault_fifo_size, GFP_KERNEL);
+	if (!vinst->fault_fifo) {
+		pr_err("Unable to alloc %d bytes for fault_fifo\n",
+				vinst->fault_fifo_size);
+		return -ENOMEM;
+	}
+
+	vas_init_rx_win_attr(&attr, VAS_COP_TYPE_FAULT);
+
+	attr.rx_fifo_size = vinst->fault_fifo_size;
+	attr.rx_fifo = vinst->fault_fifo;
+
+	/*
+	 * Max creds is based on number of CRBs can fit in the FIFO.
+	 * (fault_fifo_size/CRB_SIZE). If 8MB FIFO is used, max creds
+	 * will be 0xffff since the receive creds field is 16bits wide.
+	 */
+	attr.wcreds_max = vinst->fault_fifo_size / CRB_SIZE;
+	attr.lnotify_lpid = 0;
+	attr.lnotify_pid = mfspr(SPRN_PID);
+	attr.lnotify_tid = mfspr(SPRN_PID);
+
+	vinst->fault_win = vas_rx_win_open(vinst->vas_id, VAS_COP_TYPE_FAULT,
+					&attr);
+
+	if (IS_ERR(vinst->fault_win)) {
+		pr_err("VAS: Error %ld opening FaultWin\n",
+			PTR_ERR(vinst->fault_win));
+		kfree(vinst->fault_fifo);
+		return PTR_ERR(vinst->fault_win);
+	}
+
+	pr_devel("VAS: Created FaultWin %d, LPID/PID/TID [%d/%d/%d]\n",
+			vinst->fault_win->winid, attr.lnotify_lpid,
+			attr.lnotify_pid, attr.lnotify_tid);
+
+	return 0;
+}
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 0c0d27d..f07f49a 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -827,9 +827,10 @@ void vas_init_rx_win_attr(struct vas_rx_win_attr *rxattr, enum vas_cop_type cop)
 		rxattr->fault_win = true;
 		rxattr->notify_disable = true;
 		rxattr->rx_wcred_mode = true;
-		rxattr->tx_wcred_mode = true;
 		rxattr->rx_win_ord_mode = true;
 		rxattr->tx_win_ord_mode = true;
+		rxattr->rej_no_credit = true;
+		rxattr->tc_mode = VAS_THRESH_DISABLED;
 	} else if (cop == VAS_COP_TYPE_FTW) {
 		rxattr->user_win = true;
 		rxattr->intr_disable = true;
diff --git a/arch/powerpc/platforms/powernv/vas.c b/arch/powerpc/platforms/powernv/vas.c
index 40d8213..ec34c06 100644
--- a/arch/powerpc/platforms/powernv/vas.c
+++ b/arch/powerpc/platforms/powernv/vas.c
@@ -23,6 +23,15 @@
 
 static DEFINE_PER_CPU(int, cpu_vas_id);
 
+static int vas_irq_fault_window_setup(struct vas_instance *vinst)
+{
+	int rc = 0;
+
+	rc = vas_setup_fault_window(vinst);
+
+	return rc;
+}
+
 static int init_vas_instance(struct platform_device *pdev)
 {
 	struct device_node *dn = pdev->dev.of_node;
@@ -106,6 +115,21 @@ static int init_vas_instance(struct platform_device *pdev)
 	list_add(&vinst->node, &vas_instances);
 	mutex_unlock(&vas_mutex);
 
+	/*
+	 * IRQ and fault handling setup is needed only for user space
+	 * send windows.
+	 */
+	if (vinst->virq) {
+		rc = vas_irq_fault_window_setup(vinst);
+		/*
+		 * Fault window is used only for user space send windows.
+		 * So if vinst->virq is NULL, tx_win_open returns -ENODEV
+		 * for user space.
+		 */
+		if (rc)
+			vinst->virq = 0;
+	}
+
 	vas_instance_init_dbgdir(vinst);
 
 	dev_set_drvdata(&pdev->dev, vinst);
diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
index 598608b..9f08daa 100644
--- a/arch/powerpc/platforms/powernv/vas.h
+++ b/arch/powerpc/platforms/powernv/vas.h
@@ -315,6 +315,10 @@ struct vas_instance {
 
 	u64 irq_port;
 	int virq;
+	int fault_fifo_size;
+	void *fault_fifo;
+	struct vas_window *fault_win; /* Fault window */
+
 	struct mutex mutex;
 	struct vas_window *rxwin[VAS_COP_TYPE_MAX];
 	struct vas_window *windows[VAS_WINDOWS_PER_CHIP];
@@ -408,6 +412,7 @@ struct vas_winctx {
 extern void vas_instance_init_dbgdir(struct vas_instance *vinst);
 extern void vas_window_init_dbgdir(struct vas_window *win);
 extern void vas_window_free_dbgdir(struct vas_window *win);
+extern int vas_setup_fault_window(struct vas_instance *vinst);
 
 static inline void vas_log_write(struct vas_window *win, char *name,
 			void *regptr, u64 val)
-- 
1.8.3.1




  parent reply	other threads:[~2019-12-09  3:32 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-09  3:18 [PATCH V2 00/13] powerpc/vas: Page fault handling for user space NX requests Haren Myneni
2019-12-09  3:26 ` [PATCH V2 01/13] powerpc/vas: Describe vas-port and interrupts properties Haren Myneni
2019-12-09  3:27 ` [PATCH V2 02/13] powerpc/vas: Define nx_fault_stamp in coprocessor_request_block Haren Myneni
2019-12-09  3:29 ` [PATCH V2 03/13] powerpc/vas: Read interrupts and vas-port device tree properties Haren Myneni
2019-12-09  3:30 ` Haren Myneni [this message]
2019-12-12 12:55   ` [PATCH V2 04/13] powerpc/vas: Setup fault window per VAS instance Christoph Hellwig
2019-12-09  3:31 ` [PATCH V2 05/13] powerpc/vas: Setup thread IRQ handler " Haren Myneni
2019-12-12 12:59   ` Christoph Hellwig
2019-12-09  3:32 ` [PATCH V2 06/13] powerpc/vas: Register NX with fault window ID and IRQ port value Haren Myneni
2019-12-09  3:32 ` [PATCH V2 07/13] powerpc/vas: Take reference to PID and mm for user space windows Haren Myneni
2019-12-12 13:02   ` Christoph Hellwig
2019-12-17  5:35     ` Haren Myneni
2019-12-09  3:33 ` [PATCH V2 08/13] powerpc/vas: Update CSB and notify process for fault CRBs Haren Myneni
2019-12-12 13:07   ` Christoph Hellwig
2019-12-09  3:34 ` [PATCH V2 09/13] powerpc/vas: Print CRB and FIFO values Haren Myneni
2019-12-09  3:34 ` [PATCH V2 10/13] powerpc/vas: Do not use default credits for receive window Haren Myneni
2019-12-09  3:35 ` [PATCH V2 11/13] powerpc/vas: Return credits after handling fault Haren Myneni
2019-12-09  3:36 ` [PATCH V2 12/13] powerpc/vas: Display process stuck message Haren Myneni
2019-12-09  3:37 ` [PATCH V2 13/13] powerpc/vas: Free send window in VAS instance after credits returned Haren Myneni
2019-12-09  5:37 ` [PATCH V2 00/13] powerpc/vas: Page fault handling for user space NX requests Christophe Leroy
2019-12-09  8:38   ` Segher Boessenkool
2019-12-12  5:05     ` Haren Myneni
2019-12-12  5:38 ` Haren Myneni

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