drm/amdgpu: fix VRAM partially encroached issue in GDDR6 memory training(V2)

[why]
In GDDR6 BIST training, a certain mount of bottom VRAM will be encroached by
UMC, that causes problems(like GTT corrupted and page fault observed).

[how]
Saving the content of this bottom VRAM to system memory before training, and
restoring it after training to avoid VRAM corruption.

Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Tianci.Yin <tianci.yin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.h
index 3265487..6110215 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.h
@@ -172,6 +172,8 @@ struct psp_dtm_context {
 #define MEM_TRAIN_SYSTEM_SIGNATURE             0x54534942
 #define GDDR6_MEM_TRAINING_DATA_SIZE_IN_BYTES  0x1000
 #define GDDR6_MEM_TRAINING_OFFSET              0x8000
+/*Define the VRAM size that will be encroached by BIST training.*/
+#define GDDR6_MEM_TRAINING_ENCROACHED_SIZE     0x2000000
 
 enum psp_memory_training_init_flag {
        PSP_MEM_TRAIN_NOT_SUPPORT       = 0x0,

diff --git a/drivers/gpu/drm/amd/amdgpu/psp_v11_0.c b/drivers/gpu/drm/amd/amdgpu/psp_v11_0.c
index 685dd97..ac173d2 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/psp_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/psp_v11_0.c
@@ -971,10 +971,13 @@ Err_out:
  */
 static int psp_v11_0_memory_training(struct psp_context *psp, uint32_t ops)
 {
-       int ret;
-       uint32_t p2c_header[4];
        struct psp_memory_training_context *ctx = &psp->mem_train_ctx;
        uint32_t *pcache = (uint32_t*)ctx->sys_cache;
+       struct amdgpu_device *adev = psp->adev;
+       uint32_t p2c_header[4];
+       uint32_t sz;
+       void *buf;
+       int ret;
 
        if (ctx->init == PSP_MEM_TRAIN_NOT_SUPPORT) {
                DRM_DEBUG("Memory training is not supported.\n");
@@ -989,7 +992,7 @@ static int psp_v11_0_memory_training(struct psp_context *psp, uint32_t ops)
                return 0;
        }
 
-       amdgpu_device_vram_access(psp->adev, ctx->p2c_train_data_offset, p2c_header, sizeof(p2c_header), false);
+       amdgpu_device_vram_access(adev, ctx->p2c_train_data_offset, p2c_header, sizeof(p2c_header), false);
        DRM_DEBUG("sys_cache[%08x,%08x,%08x,%08x] p2c_header[%08x,%08x,%08x,%08x]\n",
                  pcache[0], pcache[1], pcache[2], pcache[3],
                  p2c_header[0], p2c_header[1], p2c_header[2], p2c_header[3]);
@@ -1026,11 +1029,38 @@ static int psp_v11_0_memory_training(struct psp_context *psp, uint32_t ops)
        DRM_DEBUG("Memory training ops:%x.\n", ops);
 
        if (ops & PSP_MEM_TRAIN_SEND_LONG_MSG) {
+               /*
+                * Long traing will encroach certain mount of bottom VRAM,
+                * saving the content of this bottom VRAM to system memory
+                * before training, and restoring it after training to avoid
+                * VRAM corruption.
+                */
+               sz = GDDR6_MEM_TRAINING_ENCROACHED_SIZE;
+
+               if (adev->gmc.visible_vram_size < sz || !adev->mman.aper_base_kaddr) {
+                       DRM_ERROR("visible_vram_size %llx or aper_base_kaddr %p is not initialized.\n",
+                                 adev->gmc.visible_vram_size,
+                                 adev->mman.aper_base_kaddr);
+                       return -EINVAL;
+               }
+
+               buf = vmalloc(sz);
+               if (!buf) {
+                       DRM_ERROR("failed to allocate system memory.\n");
+                       return -ENOMEM;
+               }
+
+               memcpy_fromio(buf, adev->mman.aper_base_kaddr, sz);
                ret = psp_v11_0_memory_training_send_msg(psp, PSP_BL__DRAM_LONG_TRAIN);
                if (ret) {
                        DRM_ERROR("Send long training msg failed.\n");
+                       vfree(buf);
                        return ret;
                }
+
+               memcpy_toio(adev->mman.aper_base_kaddr, buf, sz);
+               adev->nbio.funcs->hdp_flush(adev, NULL);
+               vfree(buf);
        }
 
        if (ops & PSP_MEM_TRAIN_SAVE) {