[PATCH 1/3] drm/amdgpu: recreate retired page's bo if vram get lost in gpu reset

[Zhou1, Tao]

the info of retired page's bo may be lost if vram lost is encountered
in gpu reset (gpu page table in vram may be lost), force to recreate
all bos

v2: simplify NULL pointer check
    add more comments

Signed-off-by: Tao Zhou <tao.zhou1 at amd.com>
Suggested-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c    | 48 ++++++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h    |  1 +
 3 files changed, 50 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 62955156653c..a89f6d053b3f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3675,6 +3675,7 @@ static int amdgpu_do_asic_reset(struct amdgpu_hive_info *hive,
 				if (vram_lost) {
 					DRM_INFO("VRAM is lost due to GPU reset!\n");
 					amdgpu_inc_vram_lost(tmp_adev);
+					amdgpu_ras_recovery_reset(tmp_adev);
 				}
 
 				r = amdgpu_gtt_mgr_recover(
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
index 486568ded6d6..3f2a2f13e4c6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
@@ -1573,6 +1573,54 @@ static int amdgpu_ras_recovery_fini(struct amdgpu_device *adev)
 
 	return 0;
 }
+
+/*
+ * the info of retired page's bo may be lost if vram lost is encountered
+ * in gpu reset (gpu page table in vram may be lost), force to recreate
+ * all bos
+ */
+void amdgpu_ras_recovery_reset(struct amdgpu_device *adev)
+{
+	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
+	struct ras_err_handler_data *data;
+	uint64_t bp;
+	struct amdgpu_bo *bo = NULL;
+	int i;
+
+	if (!con || !con->eh_data)
+		return;
+
+	/* Note: It's called in gpu reset, recovery_lock may be acquired before
+	 * gpu reset. The following code is out of protect of con->recovery_lock
+	 * in case of deadlock and bps_bo should be recreated (if successfully)
+	 * whether recovery_lock is locked or not.
+	 * We assume there is no other ras recovery operation simultaneous during
+	 * gpu reset.
+	 */
+	data = con->eh_data;
+	/* force to reserve all retired page again */
+	data->last_reserved = 0;
+
+	for (i = data->last_reserved; i < data->count; i++) {
+		bp = data->bps[i].retired_page;
+
+		/* There are three cases of reserve error should be ignored:
+		 * 1) a ras bad page has been allocated (used by someone);
+		 * 2) a ras bad page has been reserved (duplicate error injection
+		 *    for one page);
+		 * 3) bo info isn't lost in gpu reset
+		 */
+		if (amdgpu_bo_create_kernel_at(adev, bp << AMDGPU_GPU_PAGE_SHIFT,
+					       AMDGPU_GPU_PAGE_SIZE,
+					       AMDGPU_GEM_DOMAIN_VRAM,
+					       &bo, NULL))
+			DRM_NOTE("RAS NOTE: recreate bo for retired page 0x%llx fail\n", bp);
+		else
+			data->bps_bo[i] = bo;
+		data->last_reserved = i + 1;
+		bo = NULL;
+	}
+}
 /* recovery end */
 
 /* return 0 if ras will reset gpu and repost.*/
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
index f80fd3428c98..7a606d3be806 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
@@ -479,6 +479,7 @@ static inline int amdgpu_ras_is_supported(struct amdgpu_device *adev,
 }
 
 int amdgpu_ras_recovery_init(struct amdgpu_device *adev);
+void amdgpu_ras_recovery_reset(struct amdgpu_device *adev);
 int amdgpu_ras_request_reset_on_boot(struct amdgpu_device *adev,
 		unsigned int block);
 
-- 
2.17.1