[PATCH 2/5] drm/xe/lrc: Extract post context restore function

[Umesh Nerlige Ramappa]

On Fri, May 23, 2025 at 11:54:36AM -0700, Lucas De Marchi wrote:
>The post context restore is a mechanism in HW that may be used for
>things other than the utilization setup. Create a new function called
>setup_post_context_restore_bb() that wraps any function writing useful
>commands in the buffer.
>
>Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
>---
> drivers/gpu/drm/xe/xe_lrc.c | 25 +++++++++++++++++--------
> 1 file changed, 17 insertions(+), 8 deletions(-)
>
>diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c
>index 61a2e87990a9d..4562049a23fb1 100644
>--- a/drivers/gpu/drm/xe/xe_lrc.c
>+++ b/drivers/gpu/drm/xe/xe_lrc.c
>@@ -917,9 +917,10 @@ static void xe_lrc_finish(struct xe_lrc *lrc)
> }
>
> /*
>- * xe_lrc_setup_utilization() - Setup wa bb to assist in calculating active
>- * context run ticks.
>+ * wa_bb_write_utilization_state() - Write commands to wa bb to assist
>+ * in calculating active context run ticks.
>  * @lrc: Pointer to the lrc.
>+ * @cmd0: Pointer to the batch buffer location.
>  *
>  * Context Timestamp (CTX_TIMESTAMP) in the LRC accumulates the run ticks of the
>  * context, but only gets updated when the context switches out. In order to
>@@ -944,11 +945,9 @@ static void xe_lrc_finish(struct xe_lrc *lrc)
>  * store it in the PPHSWP.
>  */
> #define CONTEXT_ACTIVE 1ULL
>-static void xe_lrc_setup_utilization(struct xe_lrc *lrc)
>+static size_t wa_bb_write_utilization_state(struct xe_lrc *lrc, u32 *cmd0)
> {
>-	u32 *cmd;
>-
>-	cmd = lrc->bb_per_ctx_bo->vmap.vaddr;
>+	u32 *cmd = cmd0;
>
> 	*cmd++ = MI_STORE_REGISTER_MEM | MI_SRM_USE_GGTT | MI_SRM_ADD_CS_OFFSET;
> 	*cmd++ = ENGINE_ID(0).addr;
>@@ -967,11 +966,21 @@ static void xe_lrc_setup_utilization(struct xe_lrc *lrc)
> 		*cmd++ = upper_32_bits(CONTEXT_ACTIVE);
> 	}
>
>+	return cmd - cmd0;
>+}
>+
>+static void setup_wa_bb(struct xe_lrc *lrc)
>+{
>+	u32 *cmd, *cmd0;
>+
>+	cmd0 = lrc->bb_per_ctx_bo->vmap.vaddr;
>+	cmd = cmd0;
>+
>+	cmd += wa_bb_write_utilization_state(lrc, cmd);
> 	*cmd++ = MI_BATCH_BUFFER_END;

Why not just assert right here for cmd - cmd0 instead of putting it into 
the next patch?

Thanks,
Umesh
>
> 	xe_lrc_write_ctx_reg(lrc, CTX_BB_PER_CTX_PTR,
> 			     xe_bo_ggtt_addr(lrc->bb_per_ctx_bo) | 1);
>-
> }
>
> #define PVC_CTX_ASID		(0x2e + 1)
>@@ -1128,7 +1137,7 @@ static int xe_lrc_init(struct xe_lrc *lrc, struct xe_hw_engine *hwe,
> 	map = __xe_lrc_start_seqno_map(lrc);
> 	xe_map_write32(lrc_to_xe(lrc), &map, lrc->fence_ctx.next_seqno - 1);
>
>-	xe_lrc_setup_utilization(lrc);
>+	setup_wa_bb(lrc);
>
> 	return 0;
>
>
>-- 
>2.49.0
>