[PATCH v4 07/20] drm/xe/svm: Split system allocator vma incase of madvise call

[Himal Prasad Ghimiray]

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

Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
Reviewed-by: Matthew Brost <matthew.brost at intel.com>
---
 drivers/gpu/drm/xe/xe_vm.c | 106 +++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_vm.h |   2 +
 2 files changed, 108 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 4849d4cc806a..f5f8de113eae 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -4172,3 +4172,109 @@ 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 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;
+
+	vm_dbg(&vm->xe->drm, "MADVISE IN: addr=0x%016llx, size=0x%016llx", start, range);
+
+	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_sm_map_ops_create(&vm->gpuvm, start, range,
+					  DRM_GPUVM_SKIP_GEM_OBJ_VA_SPLIT_MADVISE,
+					  NULL, start);
+	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);
+	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;
+}
diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h
index acd3fd6c605b..66bb6babd319 100644
--- a/drivers/gpu/drm/xe/xe_vm.h
+++ b/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
-- 
2.34.1