[RFC 6/8] drm/xe/pf: Add a helper function to get a VF's backing object in LMEM

[Vivek Kasireddy <vivek.kasireddy@intel.com>]

To properly import a dmabuf that is associated with a VF (or that
originates in a Guest VM that includes a VF), we need to know where
in LMEM the VF's allocated regions exist. Therefore, introduce a
new helper to return the object that backs the VF's regions in LMEM.

v2:
- Make the helper return the LMEM object instead of the start address

v3:
- Move the declaration of the helper under other lmem helpers (Michal)

Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
---
 drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c | 23 ++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h |  1 +
 2 files changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
index 6344b5205c08..1bfcd35cc8ef 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
@@ -1535,6 +1535,29 @@ u64 xe_gt_sriov_pf_config_get_lmem(struct xe_gt *gt, unsigned int vfid)
 	return size;
 }
 
+/**
+ * xe_gt_sriov_pf_config_get_lmem_obj - Get VF's LMEM BO.
+ * @gt: the &xe_gt
+ * @vfid: the VF identifier
+ *
+ * This function can only be called on PF.
+ *
+ * Return: BO that is backing VF's quota in LMEM.
+ */
+struct xe_bo *xe_gt_sriov_pf_config_get_lmem_obj(struct xe_gt *gt,
+						 unsigned int vfid)
+{
+	struct xe_gt_sriov_config *config;
+	struct xe_bo *lmem_obj;
+
+	mutex_lock(xe_gt_sriov_pf_master_mutex(gt));
+	config = pf_pick_vf_config(gt, vfid);
+	lmem_obj = config->lmem_obj;
+	mutex_unlock(xe_gt_sriov_pf_master_mutex(gt));
+
+	return lmem_obj;
+}
+
 /**
  * xe_gt_sriov_pf_config_set_lmem - Provision VF with LMEM.
  * @gt: the &xe_gt (can't be media)
diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
index 513e6512a575..bbc5c238cbf6 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
@@ -36,6 +36,7 @@ int xe_gt_sriov_pf_config_set_lmem(struct xe_gt *gt, unsigned int vfid, u64 size
 int xe_gt_sriov_pf_config_set_fair_lmem(struct xe_gt *gt, unsigned int vfid, unsigned int num_vfs);
 int xe_gt_sriov_pf_config_bulk_set_lmem(struct xe_gt *gt, unsigned int vfid, unsigned int num_vfs,
 					u64 size);
+struct xe_bo *xe_gt_sriov_pf_config_get_lmem_obj(struct xe_gt *gt, unsigned int vfid);
 
 u32 xe_gt_sriov_pf_config_get_exec_quantum(struct xe_gt *gt, unsigned int vfid);
 int xe_gt_sriov_pf_config_set_exec_quantum(struct xe_gt *gt, unsigned int vfid, u32 exec_quantum);
-- 
2.50.1