[PATCH v1 3/5] drm/xe/pf: Add a helper function to get a VF's starting address in LMEM

[Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx>]

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 region starts. The function introduced
in this patch does just that by returning the DPA associated with
the BO that backs the VF's region in LMEM.

Signed-off-by: Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx>
---
 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 a863e50b756e..b1da329244d0 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
@@ -1455,6 +1455,29 @@ u64 xe_gt_sriov_pf_config_get_lmem(struct xe_gt *gt, unsigned int vfid)
 	return size;
 }
 
+/**
+ * xe_gt_sriov_pf_config_get_lmem_addr - Get VF's LMEM starting addr.
+ * @gt: the &xe_gt
+ * @vfid: the VF identifier
+ *
+ * This function can only be called on PF.
+ *
+ * Return: VF's starting address in LMEM.
+ */
+dma_addr_t xe_gt_sriov_pf_config_get_lmem_addr(struct xe_gt *gt,
+					       unsigned int vfid)
+{
+	struct xe_gt_sriov_config *config;
+	dma_addr_t addr;
+
+	mutex_lock(xe_gt_sriov_pf_master_mutex(gt));
+	config = pf_pick_vf_config(gt, vfid);
+	addr = xe_bo_addr(config->lmem_obj, 0, PAGE_SIZE);
+	mutex_unlock(xe_gt_sriov_pf_master_mutex(gt));
+
+	return addr;
+}
+
 /**
  * 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 b74ec38baa18..af9995f094a9 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
@@ -31,6 +31,7 @@ int xe_gt_sriov_pf_config_set_fair_dbs(struct xe_gt *gt, unsigned int vfid, unsi
 int xe_gt_sriov_pf_config_bulk_set_dbs(struct xe_gt *gt, unsigned int vfid, unsigned int num_vfs,
 				       u32 num_dbs);
 
+dma_addr_t xe_gt_sriov_pf_config_get_lmem_addr(struct xe_gt *gt, unsigned int vfid);
 u64 xe_gt_sriov_pf_config_get_lmem(struct xe_gt *gt, unsigned int vfid);
 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);
-- 
2.45.1