[PATCH 3/6] drm/xe/vm: add helper to retrieve VM SVA PASID

[Nareshkumar Gollakoti <naresh.kumar.g@intel.com>]

Add xe_vm_get_sva_pasid() to return the PASID associated with a VM SVA
binding.

The helper checks whether the VM has a valid SVA handle and, if so,
returns the PASID obtained from iommu_sva_get_pasid(). If no SVA handle
is present, return -EINVAL.

Export the helper in xe_vm.h so other XE components can query the VM's
PASID when programming per-context state.

Signed-off-by: Nareshkumar Gollakoti <naresh.kumar.g@intel.com>
---
 drivers/gpu/drm/xe/xe_vm.c | 16 ++++++++++++++++
 drivers/gpu/drm/xe/xe_vm.h |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index b1d37e5a673f..dcaeeeb94721 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -1649,6 +1649,22 @@ static void xe_vm_init_prove_locking(struct xe_device *xe, struct xe_vm *vm)
 	up_read(&vm->exec_queues.lock);
 }
 
+/**
+ * xe_vm_get_sva_pasid() - get sva pasid for the vm if allocated
+ * @vm: The vm to get valid sva_handle
+ *
+ * Helper to get associated pasid for the vm which uses svm.
+ *
+ * Return: %pasid value on Success. -EINVAL if not pasid available.
+ */
+int xe_vm_get_sva_pasid(struct xe_vm *vm)
+{
+	if (!vm || !vm->sva_handle)
+		return -EINVAL;
+
+	return iommu_sva_get_pasid(vm->sva_handle);
+}
+
 static void xe_vm_sva_handle_init(struct xe_vm *vm)
 {
 	struct device *dev = vm->xe->drm.dev;
diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h
index 89c4f95984a2..fe10fd91cdfa 100644
--- a/drivers/gpu/drm/xe/xe_vm.h
+++ b/drivers/gpu/drm/xe/xe_vm.h
@@ -290,6 +290,8 @@ struct dma_fence *xe_vm_bind_kernel_bo(struct xe_vm *vm, struct xe_bo *bo,
 
 void xe_vm_resume_rebind_worker(struct xe_vm *vm);
 
+int xe_vm_get_sva_pasid(struct xe_vm *vm);
+
 /**
  * xe_vm_resv() - Return's the vm's reservation object
  * @vm: The vm
-- 
2.43.0