[RFC 10/12] drm/xe/svm: Refactor usage of drm_gpusvm* function in xe_svm

[Himal Prasad Ghimiray]

Define xe_svm_range_find_or_insert function wrapping
drm_gpusvm_range_find_or_insert for reusing in prefetch.

Define xe_svm_range_get_pages function wrapping
drm_gpusvm_range_get_pages for reusing in prefetch.

Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
---
 drivers/gpu/drm/xe/xe_svm.c | 73 +++++++++++++++++++++++++++++++------
 drivers/gpu/drm/xe/xe_svm.h | 20 ++++++++++
 2 files changed, 81 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
index 07511011aba6..5a4cb14d608e 100644
--- a/drivers/gpu/drm/xe/xe_svm.c
+++ b/drivers/gpu/drm/xe/xe_svm.c
@@ -714,7 +714,6 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma,
 			IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR) ? SZ_64K : 0,
 	};
 	struct xe_svm_range *range;
-	struct drm_gpusvm_range *r;
 	struct drm_exec exec;
 	struct dma_fence *fence;
 	ktime_t end = 0;
@@ -729,13 +728,11 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma,
 	if (err)
 		return err;
 
-	r = drm_gpusvm_range_find_or_insert(&vm->svm.gpusvm, fault_addr,
-					    xe_vma_start(vma), xe_vma_end(vma),
-					    &ctx);
-	if (IS_ERR(r))
-		return PTR_ERR(r);
+	range = xe_svm_range_find_or_insert(vm, fault_addr, vma);
+
+	if (IS_ERR(range))
+		return PTR_ERR(range);
 
-	range = to_xe_range(r);
 	if (xe_svm_range_is_valid(range, tile))
 		return 0;
 
@@ -757,13 +754,9 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma,
 	}
 
 	range_debug(range, "GET PAGES");
-	err = drm_gpusvm_range_get_pages(&vm->svm.gpusvm, r, &ctx);
+	err = xe_svm_range_get_pages(vm, range, &ctx);
 	/* Corner where CPU mappings have changed */
 	if (err == -EOPNOTSUPP || err == -EFAULT || err == -EPERM) {
-		if (err == -EOPNOTSUPP) {
-			range_debug(range, "PAGE FAULT - EVICT PAGES");
-			drm_gpusvm_range_evict(&vm->svm.gpusvm, &range->base);
-		}
 		drm_dbg(&vm->xe->drm,
 			"Get pages failed, falling back to retrying, asid=%u, gpusvm=%p, errno=%pe\n",
 			vm->usm.asid, &vm->svm.gpusvm, ERR_PTR(err));
@@ -842,6 +835,62 @@ int xe_svm_bo_evict(struct xe_bo *bo)
 	return drm_gpusvm_evict_to_ram(&bo->devmem_allocation);
 }
 
+/**
+ * xe_svm_range_find_or_insert- Find or insert GPU SVM range
+ * @vm: xe_vm pointer
+ * @addr: address for which range needs to be found/inserted
+ * @vma:  Pointer to struct xe_vma which mirrors CPU
+ *
+ * This function finds or inserts a newly allocated a SVM range based on the
+ * address.
+ *
+ * Return: Pointer to the SVM range on success, ERR_PTR() on failure.
+ */
+struct xe_svm_range *xe_svm_range_find_or_insert(struct xe_vm *vm, u64 addr,
+						 struct xe_vma *vma)
+{
+	struct drm_gpusvm_range *r;
+
+	struct drm_gpusvm_ctx ctx = {
+		.read_only = xe_vma_read_only(vma),
+		.devmem_possible = IS_DGFX(vm->xe) && IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR),
+		.check_pages_threshold = IS_DGFX(vm->xe) &&
+					 IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR) ? SZ_64K : 0,
+	};
+
+	r = drm_gpusvm_range_find_or_insert(&vm->svm.gpusvm, max(addr, xe_vma_start(vma)),
+					    xe_vma_start(vma), xe_vma_end(vma), &ctx);
+	if (IS_ERR(r))
+		return ERR_PTR(PTR_ERR(r));
+
+	return to_xe_range(r);
+}
+
+/**
+ * xe_svm_range_get_pages() - Get pages for a SVM range
+ * @vm: Pointer to the struct xe_vm
+ * @range: Pointer to the xe SVM range structure
+ * @ctx: GPU SVM context
+ *
+ * This function gets pages for a SVM range and ensures they are mapped for
+ * DMA access. In case of failure with -EOPNOTSUPP, it evicts the range.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int xe_svm_range_get_pages(struct xe_vm *vm, struct xe_svm_range *range,
+			   struct drm_gpusvm_ctx *ctx)
+{
+	int err = 0;
+
+	err = drm_gpusvm_range_get_pages(&vm->svm.gpusvm, &range->base, ctx);
+	if (err == -EOPNOTSUPP) {
+		range_debug(range, "PAGE FAULT - EVICT PAGES");
+		drm_gpusvm_range_evict(&vm->svm.gpusvm, &range->base);
+	}
+
+	return err;
+}
+
 #if IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR)
 static struct drm_pagemap_device_addr
 xe_drm_pagemap_device_map(struct drm_pagemap *dpagemap,
diff --git a/drivers/gpu/drm/xe/xe_svm.h b/drivers/gpu/drm/xe/xe_svm.h
index c8add37614ec..6bb358bf62ad 100644
--- a/drivers/gpu/drm/xe/xe_svm.h
+++ b/drivers/gpu/drm/xe/xe_svm.h
@@ -76,6 +76,12 @@ void xe_svm_range_debug(struct xe_svm_range *range, const char *operation);
 int xe_svm_alloc_vram(struct xe_vm *vm, struct xe_tile *tile,
 		      struct xe_svm_range *range,
 		      const struct drm_gpusvm_ctx *ctx);
+
+struct xe_svm_range *xe_svm_range_find_or_insert(struct xe_vm *vm, u64 addr,
+						 struct xe_vma *vma);
+
+int xe_svm_range_get_pages(struct xe_vm *vm, struct xe_svm_range *range,
+			   struct drm_gpusvm_ctx *ctx);
 #else
 static inline bool xe_svm_range_pages_valid(struct xe_svm_range *range)
 {
@@ -137,6 +143,20 @@ int xe_svm_alloc_vram(struct xe_vm *vm, struct xe_tile *tile,
 	return 0;
 }
 
+static inline
+struct xe_svm_range *xe_svm_range_find_or_insert(struct xe_vm *vm, u64 addr,
+						 struct xe_vma *vma)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline
+int xe_svm_range_get_pages(struct xe_vm *vm, struct xe_svm_range *range,
+			   struct drm_gpusvm_ctx *ctx)
+{
+	return -EINVAL;
+}
+
 #endif
 
 /**
-- 
2.34.1