[PATCH v2 03/10] VAS: Define vas_init() and vas_exit()

[Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>]

Implement vas_init() and vas_exit() functions for a new VAS module.
This VAS module is essentially a library for other device drivers
and kernel users of the NX coprocessors like NX-842 and NX-GZIP.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
Changelog[v2]:
	- Get HVWC, UWC and window address parameters from device tree.
---
 arch/powerpc/include/asm/reg.h  |   1 +
 drivers/misc/Kconfig            |   1 +
 drivers/misc/Makefile           |   1 +
 drivers/misc/vas/Kconfig        |  20 ++++++
 drivers/misc/vas/Makefile       |   3 +
 drivers/misc/vas/vas-internal.h |   3 +
 drivers/misc/vas/vas-window.c   |  19 +++++
 drivers/misc/vas/vas.c          | 156 ++++++++++++++++++++++++++++++++++++++++
 8 files changed, 204 insertions(+)
 create mode 100644 drivers/misc/vas/Kconfig
 create mode 100644 drivers/misc/vas/Makefile
 create mode 100644 drivers/misc/vas/vas-window.c
 create mode 100644 drivers/misc/vas/vas.c

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 9e1499f..9cba3c18 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1210,6 +1210,7 @@
 #define PVR_POWER8E	0x004B
 #define PVR_POWER8NVL	0x004C
 #define PVR_POWER8	0x004D
+#define PVR_POWER9	0x004E
 #define PVR_BE		0x0070
 #define PVR_PA6T	0x0090
 
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 64971ba..c84ab67 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -778,4 +778,5 @@ source "drivers/misc/mic/Kconfig"
 source "drivers/misc/genwqe/Kconfig"
 source "drivers/misc/echo/Kconfig"
 source "drivers/misc/cxl/Kconfig"
+source "drivers/misc/vas/Kconfig"
 endmenu
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 3198336..97a076e 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_GENWQE)		+= genwqe/
 obj-$(CONFIG_ECHO)		+= echo/
 obj-$(CONFIG_VEXPRESS_SYSCFG)	+= vexpress-syscfg.o
 obj-$(CONFIG_CXL_BASE)		+= cxl/
+obj-$(CONFIG_VAS)		+= vas/
 obj-$(CONFIG_PANEL)             += panel.o
 
 lkdtm-$(CONFIG_LKDTM)		+= lkdtm_core.o
diff --git a/drivers/misc/vas/Kconfig b/drivers/misc/vas/Kconfig
new file mode 100644
index 0000000..c212cea
--- /dev/null
+++ b/drivers/misc/vas/Kconfig
@@ -0,0 +1,20 @@
+#
+# IBM Virtual Accelarator Switchboard (VAS) compatible devices
+#depends on PPC_POWERNV && PCI_MSI && EEH
+#
+
+config VAS
+	tristate "Support for IBM Virtual Accelerator Switchboard (VAS)"
+	depends on PPC_POWERNV
+	default n
+	help
+	  Select this option to enable driver support for IBM Virtual
+	  Accelerator Switchboard (VAS).
+	  VAS allows accelerators in co processors like NX-842 to be
+	  directly available to a user process.  This driver enables
+	  userspace programs to access these accelerators via
+	  /dev/vas/vas-nxM.N devices.
+
+	  VAS adapters are found in POWER9 based systems.
+
+	  If unsure, say N.
diff --git a/drivers/misc/vas/Makefile b/drivers/misc/vas/Makefile
new file mode 100644
index 0000000..7dd7139
--- /dev/null
+++ b/drivers/misc/vas/Makefile
@@ -0,0 +1,3 @@
+ccflags-y			:= $(call cc-disable-warning, unused-const-variable)
+ccflags-$(CONFIG_PPC_WERROR)	+= -Werror
+obj-$(CONFIG_VAS)		+= vas.o vas-window.o
diff --git a/drivers/misc/vas/vas-internal.h b/drivers/misc/vas/vas-internal.h
index aa4e781..61cfaad 100644
--- a/drivers/misc/vas/vas-internal.h
+++ b/drivers/misc/vas/vas-internal.h
@@ -380,4 +380,7 @@ struct vas_winctx {
 	enum vas_notify_after_count notify_after_count;
 };
 
+extern int vas_initialized;
+extern int vas_window_reset(struct vas_instance *vinst, int winid);
+extern struct vas_instance *find_vas_instance(int vasid);
 #endif
diff --git a/drivers/misc/vas/vas-window.c b/drivers/misc/vas/vas-window.c
new file mode 100644
index 0000000..468f3bf
--- /dev/null
+++ b/drivers/misc/vas/vas-window.c
@@ -0,0 +1,19 @@
+/*
+ * Copyright 2016 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <asm/vas.h>
+#include "vas-internal.h"
+
+/* stub for now */
+int vas_window_reset(struct vas_instance *vinst, int winid)
+{
+	return 0;
+}
diff --git a/drivers/misc/vas/vas.c b/drivers/misc/vas/vas.c
new file mode 100644
index 0000000..1e28d10
--- /dev/null
+++ b/drivers/misc/vas/vas.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright 2016 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <asm/vas.h>
+#include "vas-internal.h"
+
+int vas_initialized;
+int vas_num_instances;
+struct vas_instance *vas_instances;
+
+static void init_vas_chip(struct vas_instance *vinst)
+{
+	int i;
+
+	for (i = 0; i < VAS_MAX_WINDOWS_PER_CHIP; i++)
+		vas_window_reset(vinst, i);
+}
+
+static int init_vas_instance(struct device_node *dn,
+				struct vas_instance *vinst)
+{
+	int rc;
+	const __be32 *p;
+
+	ida_init(&vinst->ida);
+	mutex_init(&vinst->mutex);
+
+	p = of_get_property(dn, "vas-id", NULL);
+	if (!p) {
+		pr_err("VAS: NULL vas-id? %p\n", p);
+		return -ENODEV;
+	}
+
+	vinst->vas_id = of_read_number(p, 1);
+
+	rc = of_property_read_u64(dn, "hvwc-bar-start", &vinst->hvwc_bar_start);
+	if (rc)
+		return rc;
+
+	rc = of_property_read_u64(dn, "hvwc-bar-size", &vinst->hvwc_bar_len);
+	if (rc)
+		return rc;
+
+	rc = of_property_read_u64(dn, "uwc-bar-start", &vinst->uwc_bar_start);
+	if (rc)
+		return rc;
+
+	rc = of_property_read_u64(dn, "uwc-bar-size", &vinst->uwc_bar_len);
+	if (rc)
+		return rc;
+
+	rc = of_property_read_u64(dn, "window-base", &vinst->win_base_addr);
+	if (rc)
+		return rc;
+
+	rc = of_property_read_u64(dn, "window-shift", &vinst->win_id_shift);
+	if (rc)
+		return rc;
+
+	init_vas_chip(vinst);
+
+	return 0;
+}
+
+/*
+ * Although this is read/used multiple times, it is written to only
+ * during initialization.
+ */
+struct vas_instance *find_vas_instance(int vasid)
+{
+	int i;
+	struct vas_instance *vinst;
+
+	for (i = 0; i < vas_num_instances; i++) {
+		vinst = &vas_instances[i];
+		if (vinst->vas_id == vasid)
+			return vinst;
+	}
+	pr_err("VAS instance for vas-id %d not found\n", vasid);
+	WARN_ON_ONCE(1);
+	return NULL;
+}
+
+
+int vas_init(void)
+{
+	int rc;
+	struct device_node *dn;
+	struct vas_instance *vinst;
+
+	if (!pvr_version_is(PVR_POWER9))
+		return -ENODEV;
+
+	vas_num_instances = 0;
+	for_each_node_by_name(dn, "vas")
+		vas_num_instances++;
+
+	if (!vas_num_instances)
+		return -ENODEV;
+
+	vas_instances = kmalloc_array(vas_num_instances, sizeof(*vinst),
+					GFP_KERNEL);
+	if (!vas_instances)
+		return -ENOMEM;
+
+	vinst = &vas_instances[0];
+	for_each_node_by_name(dn, "vas") {
+		rc = init_vas_instance(dn, vinst);
+		if (rc) {
+			pr_err("Error %d initializing VAS instance %ld\n", rc,
+					(vinst-&vas_instances[0]));
+			goto cleanup;
+		}
+		vinst++;
+	}
+
+	rc = -ENODEV;
+	if (vinst == &vas_instances[0]) {
+		/* Should not happen as we saw some above. */
+		pr_err("VAS: Did not find any VAS DT nodes now!\n");
+		goto cleanup;
+	}
+
+	pr_devel("VAS: Initialized %d instances\n", vas_num_instances);
+	vas_initialized = 1;
+
+	return 0;
+
+cleanup:
+	kfree(vas_instances);
+	return rc;
+}
+
+void vas_exit(void)
+{
+	vas_initialized = 0;
+	kfree(vas_instances);
+}
+
+module_init(vas_init);
+module_exit(vas_exit);
+MODULE_DESCRIPTION("IBM Virtual Accelerator Switchboard");
+MODULE_AUTHOR("Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>");
+MODULE_LICENSE("GPL");
-- 
2.7.4