On 17-07-14 06:08 AM, Christian König wrote:
> Am 13.07.2017 um 23:08 schrieb Felix Kuehling:
>> Allows gdb to access contents of user mode mapped VRAM BOs.
>>
>> Signed-off-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 59
>> +++++++++++++++++++++++++++++++++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 2 ++
>> 2 files changed, 61 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> index ff5614b..d65551d 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> @@ -1115,6 +1115,64 @@ static bool
>> amdgpu_ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
>> return ttm_bo_eviction_valuable(bo, place);
>> }
>> +static int amdgpu_ttm_access_vram(struct ttm_buffer_object *bo,
>> + unsigned long offset,
>> + void *buf, int len, int write)
>> +{
>> + struct amdgpu_bo *abo = container_of(bo, struct amdgpu_bo, tbo);
>> + struct amdgpu_device *adev = amdgpu_ttm_adev(abo->tbo.bdev);
>> + struct drm_mm_node *nodes = abo->tbo.mem.mm_node;
>> + uint32_t value = 0;
>> + int result = 0;
>> + uint64_t pos;
>> + unsigned long flags;
>> +
>> + while (offset >= (nodes->size << PAGE_SHIFT)) {
>> + offset -= nodes->size << PAGE_SHIFT;
>> + ++nodes;
>> + }
>> + pos = (nodes->start << PAGE_SHIFT) + offset;
>
> This silently assumes that a read would never cross a node boundary,
> doesn't it?
It doesn't. See below ...
>
> Christian.
>
>> +
>> + while (len && pos < adev->mc.mc_vram_size) {
>> + uint64_t aligned_pos = pos & ~(uint64_t)3;
>> + uint32_t bytes = 4 - (pos & 3);
>> + uint32_t shift = (pos & 3) * 8;
>> + uint32_t mask = 0xffffffff << shift;
>> +
>> + if (len < bytes) {
>> + mask &= 0xffffffff >> (bytes - len) * 8;
>> + bytes = len;
>> + }
>> +
>> + spin_lock_irqsave(&adev->mmio_idx_lock, flags);
>> + WREG32(mmMM_INDEX, ((uint32_t)aligned_pos) | 0x80000000);
>> + WREG32(mmMM_INDEX_HI, aligned_pos >> 31);
>> + if (!write || mask != 0xffffffff)
>> + value = RREG32(mmMM_DATA);
>> + if (write) {
>> + value &= ~mask;
>> + value |= (*(uint32_t *)buf << shift) & mask;
>> + WREG32(mmMM_DATA, value);
>> + }
>> + spin_unlock_irqrestore(&adev->mmio_idx_lock, flags);
>> + if (!write) {
>> + value = (value & mask) >> shift;
>> + memcpy(buf, &value, bytes);
>> + }
>> +
>> + result += bytes;
>> + buf = (uint8_t *)buf + bytes;
>> + pos += bytes;
>> + len -= bytes;
>> + if (pos >= (nodes->start + nodes->size) << PAGE_SHIFT) {
>> + ++nodes;
>> + pos = (nodes->start << PAGE_SHIFT);
... Here I handle crossing a node boundary. Yes, I actually added this
case to my kfdtest unit test and made sure it works, along with all odd
alignments that the code above handles.
Regards,
Felix
>> + }
>> + }
>> +
>> + return result;
>> +}
>> +
>> static struct ttm_bo_driver amdgpu_bo_driver = {
>> .ttm_tt_create = &amdgpu_ttm_tt_create,
>> .ttm_tt_populate = &amdgpu_ttm_tt_populate,
>> @@ -1130,6 +1188,7 @@ static bool
>> amdgpu_ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
>> .io_mem_reserve = &amdgpu_ttm_io_mem_reserve,
>> .io_mem_free = &amdgpu_ttm_io_mem_free,
>> .io_mem_pfn = amdgpu_ttm_io_mem_pfn,
>> + .access_vram = &amdgpu_ttm_access_vram
>> };
>> int amdgpu_ttm_init(struct amdgpu_device *adev)
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> index f137c24..a22e430 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> @@ -78,6 +78,8 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo,
>> struct dma_fence **fence);
>> int amdgpu_mmap(struct file *filp, struct vm_area_struct *vma);
>> +int amdgpu_bo_mmap(struct file *filp, struct vm_area_struct *vma,
>> + struct ttm_bo_device *bdev);
>> bool amdgpu_ttm_is_bound(struct ttm_tt *ttm);
>> int amdgpu_ttm_bind(struct ttm_buffer_object *bo, struct
>> ttm_mem_reg *bo_mem);
>> int amdgpu_ttm_recover_gart(struct amdgpu_device *adev);
>
>
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