drm/nouveau/fault/gv100-: expose VoltaFaultBufferA

This nvclass exposes the replayable fault buffer, which will be used
by SVM to manage GPU page faults.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/include/nvif/class.h

@@ -55,6 +55,7 @@
 #define VOLTA_USERMODE_A                                             0x0000c361
 
 #define MAXWELL_FAULT_BUFFER_A                        /* clb069.h */ 0x0000b069
+#define VOLTA_FAULT_BUFFER_A                          /* clb069.h */ 0x0000c369
 
 #define NV03_CHANNEL_DMA                              /* cl506b.h */ 0x0000006b
 #define NV10_CHANNEL_DMA                              /* cl506b.h */ 0x0000006e

drivers/gpu/drm/nouveau/nvkm/subdev/fault/gv100.c

@@ -25,6 +25,8 @@
 #include <subdev/mmu.h>
 #include <engine/fifo.h>
 
+#include <nvif/class.h>
+
 static void
 gv100_fault_buffer_process(struct nvkm_fault_buffer *buffer)
 {
@@ -166,6 +168,13 @@ gv100_fault_intr(struct nvkm_fault *fault)
 		}
 	}
 
+	if (stat & 0x08000000) {
+		if (fault->buffer[1]) {
+			nvkm_event_send(&fault->event, 1, 1, NULL, 0);
+			stat &= ~0x08000000;
+		}
+	}
+
 	if (stat) {
 		nvkm_debug(subdev, "intr %08x\n", stat);
 	}
@@ -208,6 +217,13 @@ gv100_fault = {
 	.buffer.init = gv100_fault_buffer_init,
 	.buffer.fini = gv100_fault_buffer_fini,
 	.buffer.intr = gv100_fault_buffer_intr,
+	/*TODO: Figure out how to expose non-replayable fault buffer, which,
+	 *      for some reason, is where recoverable CE faults appear...
+	 *
+	 * 	It's a bit tricky, as both NVKM and SVM will need access to
+	 * 	the non-replayable fault buffer.
+	 */
+	.user = { { 0, 0, VOLTA_FAULT_BUFFER_A }, 1 },
 };
 
 int

drivers/gpu/drm/nouveau/nvkm/subdev/fault/tu102.c

@@ -157,6 +157,7 @@ tu102_fault = {
 	.buffer.init = tu102_fault_buffer_init,
 	.buffer.fini = tu102_fault_buffer_fini,
 	.buffer.intr = tu102_fault_buffer_intr,
+	.user = { { 0, 0, VOLTA_FAULT_BUFFER_A }, 1 },
 };
 
 int