[PATCH] drm/amdkfd: fix dma mapping leaking warning

[Philip Yang]

For xnack off, restore work dma unmap previous system memory page, and
dma map the updated system memory page to update GPU mapping, this is
not dma mapping leaking, remove the WARN_ONCE for dma mapping leaking.

prange->dma_addr store the VRAM page pfn after the range migrated to
VRAM, should not dma unmap VRAM page when updating GPU mapping or
remove prange. Add helper svm_is_valid_dma_mapping_addr to check VRAM
page and error cases.

Keep SVM_RANGE_VRAM_DOMAIN flag in dma_addr to diff VRAM page and dma
map page, but move it to bit 8 to avoid amdgpu vm update mapping path
BUG_ON(*addr & 0xFFFF00000000003FULL).

Signed-off-by: Philip Yang <Philip.Yang at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 13 +++++++++----
 drivers/gpu/drm/amd/amdkfd/kfd_svm.h |  2 +-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 2e3ee9c46a10..237ff2d0a8d9 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -118,6 +118,13 @@ static void svm_range_remove_notifier(struct svm_range *prange)
 		mmu_interval_notifier_remove(&prange->notifier);
 }
 
+static bool
+svm_is_valid_dma_mapping_addr(struct device *dev, dma_addr_t dma_addr)
+{
+	return dma_addr && !dma_mapping_error(dev, dma_addr) &&
+	       !(dma_addr & SVM_RANGE_VRAM_DOMAIN);
+}
+
 static int
 svm_range_dma_map_dev(struct amdgpu_device *adev, struct svm_range *prange,
 		      unsigned long offset, unsigned long npages,
@@ -139,8 +146,7 @@ svm_range_dma_map_dev(struct amdgpu_device *adev, struct svm_range *prange,
 
 	addr += offset;
 	for (i = 0; i < npages; i++) {
-		if (WARN_ONCE(addr[i] && !dma_mapping_error(dev, addr[i]),
-			      "leaking dma mapping\n"))
+		if (svm_is_valid_dma_mapping_addr(dev, addr[i]))
 			dma_unmap_page(dev, addr[i], PAGE_SIZE, dir);
 
 		page = hmm_pfn_to_page(hmm_pfns[i]);
@@ -209,7 +215,7 @@ void svm_range_dma_unmap(struct device *dev, dma_addr_t *dma_addr,
 		return;
 
 	for (i = offset; i < offset + npages; i++) {
-		if (!dma_addr[i] || dma_mapping_error(dev, dma_addr[i]))
+		if (!svm_is_valid_dma_mapping_addr(dev, dma_addr[i]))
 			continue;
 		pr_debug("dma unmapping 0x%llx\n", dma_addr[i] >> PAGE_SHIFT);
 		dma_unmap_page(dev, dma_addr[i], PAGE_SIZE, dir);
@@ -1177,7 +1183,6 @@ svm_range_map_to_gpu(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 
 	for (i = offset; i < offset + npages; i++) {
 		last_domain = dma_addr[i] & SVM_RANGE_VRAM_DOMAIN;
-		dma_addr[i] &= ~SVM_RANGE_VRAM_DOMAIN;
 
 		if ((prange->start + i) < prange->last &&
 		    i + 1 < offset + npages &&
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.h b/drivers/gpu/drm/amd/amdkfd/kfd_svm.h
index 6dc91c33e80f..f53399fd37c6 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.h
@@ -35,7 +35,7 @@
 #include "amdgpu.h"
 #include "kfd_priv.h"
 
-#define SVM_RANGE_VRAM_DOMAIN (1UL << 0)
+#define SVM_RANGE_VRAM_DOMAIN (1UL << 8)
 #define SVM_ADEV_PGMAP_OWNER(adev)\
 			((adev)->hive ? (void *)(adev)->hive : (void *)(adev))
 
-- 
2.17.1