[PATCH v3 5/8] drm/amdkfd: Implement batch userptr page management

[Honglei Huang <honglei1.huang@amd.com>]

From: Honglei Huang <honghuan@amd.com>

Add core page management functions for batch userptr allocations.

This adds:
- get_user_pages_batch(): gets user pages for a single range within
  a batch allocation using HMM
- set_user_pages_batch(): populates TTM page array from multiple
  HMM ranges

Signed-off-by: Honglei Huang <honghuan@amd.com>
---
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index af6db20de..7aca1868d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -1200,6 +1200,60 @@ static const struct mmu_interval_notifier_ops amdgpu_amdkfd_hsa_batch_ops = {
 	.invalidate = amdgpu_amdkfd_invalidate_userptr_batch,
 };
 
+static int get_user_pages_batch(struct mm_struct *mm,
+				struct kgd_mem *mem,
+				struct user_range_info *range,
+				struct hmm_range **range_hmm, bool readonly)
+{
+	struct vm_area_struct *vma;
+	int r = 0;
+
+	*range_hmm = NULL;
+
+	if (!mmget_not_zero(mm))
+		return -ESRCH;
+
+	mmap_read_lock(mm);
+	vma = vma_lookup(mm, range->start);
+	if (unlikely(!vma)) {
+		r = -EFAULT;
+		goto out_unlock;
+	}
+
+	r = amdgpu_hmm_range_get_pages(&mem->batch_notifier, range->start,
+				       range->size >> PAGE_SHIFT, readonly,
+				       NULL, range_hmm);
+
+out_unlock:
+	mmap_read_unlock(mm);
+	mmput(mm);
+	return r;
+}
+
+static int set_user_pages_batch(struct ttm_tt *ttm,
+				struct user_range_info *ranges,
+				uint32_t nranges)
+{
+	uint32_t i, j, k = 0, range_npfns;
+
+	for (i = 0; i < nranges; ++i) {
+		if (!ranges[i].range || !ranges[i].range->hmm_pfns)
+			return -EINVAL;
+
+		range_npfns = (ranges[i].range->end - ranges[i].range->start) >>
+			      PAGE_SHIFT;
+
+		if (k + range_npfns > ttm->num_pages)
+			return -EOVERFLOW;
+
+		for (j = 0; j < range_npfns; ++j)
+			ttm->pages[k++] =
+				hmm_pfn_to_page(ranges[i].range->hmm_pfns[j]);
+	}
+
+	return 0;
+}
+
 /* Reserving a BO and its page table BOs must happen atomically to
  * avoid deadlocks. Some operations update multiple VMs at once. Track
  * all the reservation info in a context structure. Optionally a sync
-- 
2.34.1