Commit 3a1edef8 authored by Matthew Brost's avatar Matthew Brost
Browse files

drm/xe: Make WA BB part of LRC BO 



No idea why, but without this GuC context switches randomly fail when
running IGTs in a loop. Need to follow up why this fixes the
aforementioned issue but can live with a stable driver for now.

Fixes: 617d824c ("drm/xe: Add WA BB to capture active context utilization")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Reviewed-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
Tested-by: default avatarShuicheng Lin <shuicheng.lin@intel.com>
Link: https://lore.kernel.org/r/20250612031925.4009701-1-matthew.brost@intel.com
parent 0fccfb63

drivers/gpu/drm/xe/xe_lrc.c

+18 −18
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 


#define LRC_PPHWSP_SIZE				SZ_4K

#define LRC_INDIRECT_RING_STATE_SIZE		SZ_4K

#define LRC_WA_BB_SIZE				SZ_4K



static struct xe_device *

lrc_to_xe(struct xe_lrc *lrc)
@@ -910,7 +911,6 @@ static void xe_lrc_finish(struct xe_lrc *lrc) 
{

	xe_hw_fence_ctx_finish(&lrc->fence_ctx);

	xe_bo_unpin_map_no_vm(lrc->bo);

	xe_bo_unpin_map_no_vm(lrc->bb_per_ctx_bo);

}



/*
@@ -973,22 +973,27 @@ struct wa_bb_setup { 
			 u32 *batch, size_t max_size);

};



static size_t wa_bb_offset(struct xe_lrc *lrc)

{

	return lrc->bo->size - LRC_WA_BB_SIZE;

}



static int setup_wa_bb(struct xe_lrc *lrc, struct xe_hw_engine *hwe)

{

	const size_t max_size = lrc->bb_per_ctx_bo->size;

	const size_t max_size = LRC_WA_BB_SIZE;

	static const struct wa_bb_setup funcs[] = {

		{ .setup = wa_bb_setup_utilization },

	};

	ssize_t remain;

	u32 *cmd, *buf = NULL;



	if (lrc->bb_per_ctx_bo->vmap.is_iomem) {

	if (lrc->bo->vmap.is_iomem) {

		buf = kmalloc(max_size, GFP_KERNEL);

		if (!buf)

			return -ENOMEM;

		cmd = buf;

	} else {

		cmd = lrc->bb_per_ctx_bo->vmap.vaddr;

		cmd = lrc->bo->vmap.vaddr + wa_bb_offset(lrc);

	}



	remain = max_size / sizeof(*cmd);
@@ -1011,13 +1016,14 @@ static int setup_wa_bb(struct xe_lrc *lrc, struct xe_hw_engine *hwe) 
	*cmd++ = MI_BATCH_BUFFER_END;



	if (buf) {

		xe_map_memcpy_to(gt_to_xe(lrc->gt), &lrc->bb_per_ctx_bo->vmap, 0,

				 buf, (cmd - buf) * sizeof(*cmd));

		xe_map_memcpy_to(gt_to_xe(lrc->gt), &lrc->bo->vmap,

				 wa_bb_offset(lrc), buf,

				 (cmd - buf) * sizeof(*cmd));

		kfree(buf);

	}



	xe_lrc_write_ctx_reg(lrc, CTX_BB_PER_CTX_PTR,

			     xe_bo_ggtt_addr(lrc->bb_per_ctx_bo) | 1);

	xe_lrc_write_ctx_reg(lrc, CTX_BB_PER_CTX_PTR, xe_bo_ggtt_addr(lrc->bo) +

			     wa_bb_offset(lrc) + 1);



	return 0;
@@ -1059,20 +1065,13 @@ static int xe_lrc_init(struct xe_lrc *lrc, struct xe_hw_engine *hwe, 
	 * FIXME: Perma-pinning LRC as we don't yet support moving GGTT address

	 * via VM bind calls.

	 */

	lrc->bo = xe_bo_create_pin_map(xe, tile, NULL, lrc_size,

	lrc->bo = xe_bo_create_pin_map(xe, tile, NULL,

				       lrc_size + LRC_WA_BB_SIZE,

				       ttm_bo_type_kernel,

				       bo_flags);

	if (IS_ERR(lrc->bo))

		return PTR_ERR(lrc->bo);



	lrc->bb_per_ctx_bo = xe_bo_create_pin_map(xe, tile, NULL, SZ_4K,

						  ttm_bo_type_kernel,

						  bo_flags);

	if (IS_ERR(lrc->bb_per_ctx_bo)) {

		err = PTR_ERR(lrc->bb_per_ctx_bo);

		goto err_lrc_finish;

	}



	lrc->size = lrc_size;

	lrc->ring.size = ring_size;

	lrc->ring.tail = 0;
@@ -1860,7 +1859,8 @@ struct xe_lrc_snapshot *xe_lrc_snapshot_capture(struct xe_lrc *lrc) 
	snapshot->seqno = xe_lrc_seqno(lrc);

	snapshot->lrc_bo = xe_bo_get(lrc->bo);

	snapshot->lrc_offset = xe_lrc_pphwsp_offset(lrc);

	snapshot->lrc_size = lrc->bo->size - snapshot->lrc_offset;

	snapshot->lrc_size = lrc->bo->size - snapshot->lrc_offset -

		LRC_WA_BB_SIZE;

	snapshot->lrc_snapshot = NULL;

	snapshot->ctx_timestamp = lower_32_bits(xe_lrc_ctx_timestamp(lrc));

	snapshot->ctx_job_timestamp = xe_lrc_ctx_job_timestamp(lrc);

drivers/gpu/drm/xe/xe_lrc_types.h

+0 −3
Original line number Diff line number Diff line
@@ -53,9 +53,6 @@ struct xe_lrc { 


	/** @ctx_timestamp: readout value of CTX_TIMESTAMP on last update */

	u64 ctx_timestamp;



	/** @bb_per_ctx_bo: buffer object for per context batch wa buffer */

	struct xe_bo *bb_per_ctx_bo;

};



struct xe_lrc_snapshot;