[PATCH v6 18/20] drm/xe/svm: Add xe_svm_find_vma_start() helper

[Himal Prasad Ghimiray]

Add helper xe_svm_find_vma_start() function to determine start of cpu
vma in input range.

Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
---
 drivers/gpu/drm/xe/xe_svm.c | 22 ++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_svm.h |  8 ++++++++
 2 files changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
index fff3a279e232..727c393d19b8 100644
--- a/drivers/gpu/drm/xe/xe_svm.c
+++ b/drivers/gpu/drm/xe/xe_svm.c
@@ -684,6 +684,28 @@ bool xe_svm_range_validate(struct xe_vm *vm,
 	return ret;
 }
 
+/**
+ * xe_svm_find_vma_start - Find start of CPU VMA
+ * @vm: xe_vm pointer
+ * @start: start address
+ * @end: end address
+ * @vma: Pointer to struct xe_vma
+ *
+ *
+ * This function searches for a cpu vma, within the specified
+ * range [start, end] in the given VM. It adjusts the range based on the
+ * xe_vma start and end addresses. If no cpu VMA is found, it returns ULONG_MAX.
+ *
+ * Return: The starting address of the VMA within the range,
+ * or ULONG_MAX if no VMA is found
+ */
+u64 xe_svm_find_vma_start(struct xe_vm *vm, u64 start, u64 end, struct xe_vma *vma)
+{
+	return drm_gpusvm_find_vma_start(&vm->svm.gpusvm,
+					 max(start, xe_vma_start(vma)),
+					 min(end, xe_vma_end(vma)));
+}
+
 #if IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR)
 static struct xe_vram_region *tile_to_vr(struct xe_tile *tile)
 {
diff --git a/drivers/gpu/drm/xe/xe_svm.h b/drivers/gpu/drm/xe/xe_svm.h
index 3f8c82f9c363..fe9f6fcaeb3a 100644
--- a/drivers/gpu/drm/xe/xe_svm.h
+++ b/drivers/gpu/drm/xe/xe_svm.h
@@ -89,6 +89,8 @@ bool xe_svm_range_validate(struct xe_vm *vm,
 			   struct xe_svm_range *range,
 			   u8 tile_mask, bool devmem_preferred);
 
+u64 xe_svm_find_vma_start(struct xe_vm *vm, u64 addr, u64 end,  struct xe_vma *vma);
+
 /**
  * xe_svm_range_has_dma_mapping() - SVM range has DMA mapping
  * @range: SVM range
@@ -295,6 +297,12 @@ bool xe_svm_range_validate(struct xe_vm *vm,
 	return false;
 }
 
+static inline
+u64 xe_svm_find_vma_start(struct xe_vm *vm, u64 addr, u64 end, struct xe_vma *vma)
+{
+	return ULONG_MAX;
+}
+
 #define xe_svm_assert_in_notifier(...) do {} while (0)
 #define xe_svm_range_has_dma_mapping(...) false
 
-- 
2.34.1