drm/nv50-nv86,nv92/mc: rearm msi via pci config space, rather than mmio mirror

This is what NVIDIA do on these chipsets, let's hope it works around
the reported MSI failures for us on NV86.

v2: updated to include G92, as per information provided by NVIDIA.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/Makefile

@@ -116,6 +116,7 @@ nouveau-y += core/subdev/mc/nv04.o
 nouveau-y += core/subdev/mc/nv40.o
 nouveau-y += core/subdev/mc/nv44.o
 nouveau-y += core/subdev/mc/nv50.o
+nouveau-y += core/subdev/mc/nv94.o
 nouveau-y += core/subdev/mc/nv98.o
 nouveau-y += core/subdev/mc/nvc0.o
 nouveau-y += core/subdev/mc/nvc3.o

drivers/gpu/drm/nouveau/core/engine/device/nv50.c

@@ -164,7 +164,7 @@ nv50_identify(struct nouveau_device *device)
 		device->oclass[NVDEV_SUBDEV_THERM  ] = &nv84_therm_oclass;
 		device->oclass[NVDEV_SUBDEV_MXM    ] = &nv50_mxm_oclass;
 		device->oclass[NVDEV_SUBDEV_DEVINIT] = &nv50_devinit_oclass;
-		device->oclass[NVDEV_SUBDEV_MC     ] =  nv50_mc_oclass;
+		device->oclass[NVDEV_SUBDEV_MC     ] =  nv94_mc_oclass;
 		device->oclass[NVDEV_SUBDEV_BUS    ] = &nv50_bus_oclass;
 		device->oclass[NVDEV_SUBDEV_TIMER  ] = &nv04_timer_oclass;
 		device->oclass[NVDEV_SUBDEV_FB     ] = &nv50_fb_oclass;
@@ -190,7 +190,7 @@ nv50_identify(struct nouveau_device *device)
 		device->oclass[NVDEV_SUBDEV_THERM  ] = &nv84_therm_oclass;
 		device->oclass[NVDEV_SUBDEV_MXM    ] = &nv50_mxm_oclass;
 		device->oclass[NVDEV_SUBDEV_DEVINIT] = &nv50_devinit_oclass;
-		device->oclass[NVDEV_SUBDEV_MC     ] =  nv50_mc_oclass;
+		device->oclass[NVDEV_SUBDEV_MC     ] =  nv94_mc_oclass;
 		device->oclass[NVDEV_SUBDEV_BUS    ] = &nv50_bus_oclass;
 		device->oclass[NVDEV_SUBDEV_TIMER  ] = &nv04_timer_oclass;
 		device->oclass[NVDEV_SUBDEV_FB     ] = &nv50_fb_oclass;

drivers/gpu/drm/nouveau/core/include/subdev/mc.h

@@ -48,6 +48,7 @@ extern struct nouveau_oclass *nv04_mc_oclass;
 extern struct nouveau_oclass *nv40_mc_oclass;
 extern struct nouveau_oclass *nv44_mc_oclass;
 extern struct nouveau_oclass *nv50_mc_oclass;
+extern struct nouveau_oclass *nv94_mc_oclass;
 extern struct nouveau_oclass *nv98_mc_oclass;
 extern struct nouveau_oclass *nvc0_mc_oclass;
 extern struct nouveau_oclass *nvc3_mc_oclass;

drivers/gpu/drm/nouveau/core/subdev/mc/nv04.h

@@ -15,6 +15,7 @@ extern const struct nouveau_mc_intr nv04_mc_intr[];
 int  nv04_mc_init(struct nouveau_object *);
 void nv40_mc_msi_rearm(struct nouveau_mc *);
 int  nv50_mc_init(struct nouveau_object *);
+extern const struct nouveau_mc_intr nv50_mc_intr[];
 extern const struct nouveau_mc_intr nvc0_mc_intr[];
 
 #endif

drivers/gpu/drm/nouveau/core/subdev/mc/nv50.c

@@ -24,7 +24,7 @@
 
 #include "nv04.h"
 
-static const struct nouveau_mc_intr
+const struct nouveau_mc_intr
 nv50_mc_intr[] = {
 	{ 0x00000001, NVDEV_ENGINE_MPEG },
 	{ 0x00000100, NVDEV_ENGINE_FIFO },
@@ -41,6 +41,13 @@ nv50_mc_intr[] = {
 	{},
 };
 
+static void
+nv50_mc_msi_rearm(struct nouveau_mc *pmc)
+{
+	struct nouveau_device *device = nv_device(pmc);
+	pci_write_config_byte(device->pdev, 0x68, 0xff);
+}
+
 int
 nv50_mc_init(struct nouveau_object *object)
 {
@@ -59,5 +66,5 @@ nv50_mc_oclass = &(struct nouveau_mc_oclass) {
 		.fini = _nouveau_mc_fini,
 	},
 	.intr = nv50_mc_intr,
-	.msi_rearm = nv40_mc_msi_rearm,
+	.msi_rearm = nv50_mc_msi_rearm,
 }.base;

drivers/gpu/drm/nouveau/core/subdev/mc/nv94.c

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2012 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Ben Skeggs
+ */
+
+#include "nv04.h"
+
+struct nouveau_oclass *
+nv94_mc_oclass = &(struct nouveau_mc_oclass) {
+	.base.handle = NV_SUBDEV(MC, 0x94),
+	.base.ofuncs = &(struct nouveau_ofuncs) {
+		.ctor = nv04_mc_ctor,
+		.dtor = _nouveau_mc_dtor,
+		.init = nv50_mc_init,
+		.fini = _nouveau_mc_fini,
+	},
+	.intr = nv50_mc_intr,
+	.msi_rearm = nv40_mc_msi_rearm,
+}.base;