drm/xe/svm: Split system allocator vma incase of madvise call

If the start or end of input address range lies within system allocator
vma split the vma to create new vma's as per input range.

v2 (Matthew Brost)
- Add lockdep_assert_write for vm->lock
- Remove unnecessary page aligned checks
- Add kerrnel-doc and comments
- Remove unnecessary unwind_ops and return

v3
- Fix copying of attributes

v4
- Nit fixes

v5
- Squash identifier for madvise in xe_vma_ops to this patch

v6/v7/v8
- Rebase on drm_gpuvm changes

Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250821173104.3030148-6-himal.prasad.ghimiray@intel.com
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>

drivers/gpu/drm/xe/xe_vm.c

@@ -4207,3 +4207,111 @@ void xe_vm_snapshot_free(struct xe_vm_snapshot *snap)
 	}
 	kvfree(snap);
 }
+
+/**
+ * xe_vm_alloc_madvise_vma - Allocate VMA's with madvise ops
+ * @vm: Pointer to the xe_vm structure
+ * @start: Starting input address
+ * @range: Size of the input range
+ *
+ * This function splits existing vma to create new vma for user provided input range
+ *
+ *  Return: 0 if success
+ */
+int xe_vm_alloc_madvise_vma(struct xe_vm *vm, uint64_t start, uint64_t range)
+{
+	struct drm_gpuvm_map_req map_req = {
+		.map.va.addr = start,
+		.map.va.range = range,
+	};
+
+	struct xe_vma_ops vops;
+	struct drm_gpuva_ops *ops = NULL;
+	struct drm_gpuva_op *__op;
+	bool is_cpu_addr_mirror = false;
+	bool remap_op = false;
+	struct xe_vma_mem_attr tmp_attr;
+	int err;
+
+	lockdep_assert_held_write(&vm->lock);
+
+	vm_dbg(&vm->xe->drm, "MADVISE_OPS_CREATE: addr=0x%016llx, size=0x%016llx", start, range);
+	ops = drm_gpuvm_madvise_ops_create(&vm->gpuvm, &map_req);
+	if (IS_ERR(ops))
+		return PTR_ERR(ops);
+
+	if (list_empty(&ops->list)) {
+		err = 0;
+		goto free_ops;
+	}
+
+	drm_gpuva_for_each_op(__op, ops) {
+		struct xe_vma_op *op = gpuva_op_to_vma_op(__op);
+
+		if (__op->op == DRM_GPUVA_OP_REMAP) {
+			xe_assert(vm->xe, !remap_op);
+			remap_op = true;
+
+			if (xe_vma_is_cpu_addr_mirror(gpuva_to_vma(op->base.remap.unmap->va)))
+				is_cpu_addr_mirror = true;
+			else
+				is_cpu_addr_mirror = false;
+		}
+
+		if (__op->op == DRM_GPUVA_OP_MAP) {
+			xe_assert(vm->xe, remap_op);
+			remap_op = false;
+
+			/* In case of madvise ops DRM_GPUVA_OP_MAP is always after
+			 * DRM_GPUVA_OP_REMAP, so ensure we assign op->map.is_cpu_addr_mirror true
+			 * if REMAP is for xe_vma_is_cpu_addr_mirror vma
+			 */
+			op->map.is_cpu_addr_mirror = is_cpu_addr_mirror;
+		}
+
+		print_op(vm->xe, __op);
+	}
+
+	xe_vma_ops_init(&vops, vm, NULL, NULL, 0);
+	vops.flags |= XE_VMA_OPS_FLAG_MADVISE;
+	err = vm_bind_ioctl_ops_parse(vm, ops, &vops);
+	if (err)
+		goto unwind_ops;
+
+	xe_vm_lock(vm, false);
+
+	drm_gpuva_for_each_op(__op, ops) {
+		struct xe_vma_op *op = gpuva_op_to_vma_op(__op);
+		struct xe_vma *vma;
+
+		if (__op->op == DRM_GPUVA_OP_UNMAP) {
+			/* There should be no unmap */
+			XE_WARN_ON("UNEXPECTED UNMAP");
+			xe_vma_destroy(gpuva_to_vma(op->base.unmap.va), NULL);
+		} else if (__op->op == DRM_GPUVA_OP_REMAP) {
+			vma = gpuva_to_vma(op->base.remap.unmap->va);
+			/* Store attributes for REMAP UNMAPPED VMA, so they can be assigned
+			 * to newly MAP created vma.
+			 */
+			tmp_attr = vma->attr;
+			xe_vma_destroy(gpuva_to_vma(op->base.remap.unmap->va), NULL);
+		} else if (__op->op == DRM_GPUVA_OP_MAP) {
+			vma = op->map.vma;
+			/* In case of madvise call, MAP will always be follwed by REMAP.
+			 * Therefore temp_attr will always have sane values, making it safe to
+			 * copy them to new vma.
+			 */
+			vma->attr = tmp_attr;
+		}
+	}
+
+	xe_vm_unlock(vm);
+	drm_gpuva_ops_free(&vm->gpuvm, ops);
+	return 0;
+
+unwind_ops:
+	vm_bind_ioctl_ops_unwind(vm, &ops, 1);
+free_ops:
+	drm_gpuva_ops_free(&vm->gpuvm, ops);
+	return err;
+}

drivers/gpu/drm/xe/xe_vm.h

@@ -171,6 +171,8 @@ static inline bool xe_vma_is_userptr(struct xe_vma *vma)
 
 struct xe_vma *xe_vm_find_vma_by_addr(struct xe_vm *vm, u64 page_addr);
 
+int xe_vm_alloc_madvise_vma(struct xe_vm *vm, uint64_t addr, uint64_t size);
+
 /**
  * to_userptr_vma() - Return a pointer to an embedding userptr vma
  * @vma: Pointer to the embedded struct xe_vma

drivers/gpu/drm/xe/xe_vm_types.h

@@ -495,6 +495,7 @@ struct xe_vma_ops {
 	struct xe_vm_pgtable_update_ops pt_update_ops[XE_MAX_TILES_PER_DEVICE];
 	/** @flag: signify the properties within xe_vma_ops*/
 #define XE_VMA_OPS_FLAG_HAS_SVM_PREFETCH BIT(0)
+#define XE_VMA_OPS_FLAG_MADVISE          BIT(1)
 	u32 flags;
 #ifdef TEST_VM_OPS_ERROR
 	/** @inject_error: inject error to test error handling */