drm/amdgpu: replace get_user_pages with HMM mirror helpers

Use HMM helper function hmm_vma_fault() to get physical pages backing
userptr and start CPU page table update track of those pages. Then use
hmm_vma_range_done() to check if those pages are updated before
amdgpu_cs_submit for gfx or before user queues are resumed for kfd.

If userptr pages are updated, for gfx, amdgpu_cs_ioctl will restart
from scratch, for kfd, restore worker is rescheduled to retry.

HMM simplify the CPU page table concurrent update check, so remove
guptasklock, mmu_invalidations, last_set_pages fields from
amdgpu_ttm_tt struct.

HMM does not pin the page (increase page ref count), so remove related
operations like release_pages(), put_page(), mark_page_dirty().

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 23 insertions, 2 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index f000704f984d..41ccee49a224 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -220,8 +220,6 @@ static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
 			true, false, MAX_SCHEDULE_TIMEOUT);
 		if (r <= 0)
 			DRM_ERROR("(%ld) failed to wait for user bo\n", r);
-
-		amdgpu_ttm_tt_mark_user_pages(bo->tbo.ttm);
 	}
 }
 
@@ -502,3 +500,26 @@ void amdgpu_mn_unregister(struct amdgpu_bo *bo)
 	mutex_unlock(&adev->mn_lock);
 }
 
+/* flags used by HMM internal, not related to CPU/GPU PTE flags */
+static const uint64_t hmm_range_flags[HMM_PFN_FLAG_MAX] = {
+		(1 << 0), /* HMM_PFN_VALID */
+		(1 << 1), /* HMM_PFN_WRITE */
+		0 /* HMM_PFN_DEVICE_PRIVATE */
+};
+
+static const uint64_t hmm_range_values[HMM_PFN_VALUE_MAX] = {
+		0xfffffffffffffffeUL, /* HMM_PFN_ERROR */
+		0, /* HMM_PFN_NONE */
+		0xfffffffffffffffcUL /* HMM_PFN_SPECIAL */
+};
+
+void amdgpu_hmm_init_range(struct hmm_range *range)
+{
+	if (range) {
+		range->flags = hmm_range_flags;
+		range->values = hmm_range_values;
+		range->pfn_shift = PAGE_SHIFT;
+		range->pfns = NULL;
+		INIT_LIST_HEAD(&range->list);
+	}
+}