Commit 0ed4b3c2 authored by Lucas De Marchi's avatar Lucas De Marchi
Browse files

drm/xe/lrc: Prepare WA BB setup for more users 



The post context restore (WA BB) is a mechanism in HW that may be used
for things other than the utilization setup. Create a new function
called setup_wa_bb() that wraps any function writing useful commands in
the buffer.

Reviewed-by: default avatarUmesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@igalia.com>
Link: https://lore.kernel.org/r/20250604-wa-bb-fix-v1-2-0dfc5dafcef0@intel.com


Signed-off-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
parent ef48715b

drivers/gpu/drm/xe/xe_lrc.c

+55 −14
Original line number Diff line number Diff line
@@ -914,9 +914,8 @@ static void xe_lrc_finish(struct xe_lrc *lrc) 
}



/*

 * xe_lrc_setup_utilization() - Setup wa bb to assist in calculating active

 * context run ticks.

 * @lrc: Pointer to the lrc.

 * wa_bb_setup_utilization() - Write commands to wa bb to assist

 * in calculating active context run ticks.

 *

 * 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
@@ -941,18 +940,13 @@ static void xe_lrc_finish(struct xe_lrc *lrc) 
 * store it in the PPHSWP.

 */

#define CONTEXT_ACTIVE 1ULL

static int xe_lrc_setup_utilization(struct xe_lrc *lrc)

static ssize_t wa_bb_setup_utilization(struct xe_lrc *lrc, struct xe_hw_engine *hwe,

				       u32 *batch, size_t max_len)

{

	u32 *cmd, *buf = NULL;

	u32 *cmd = batch;



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

		buf = kmalloc(lrc->bb_per_ctx_bo->size, GFP_KERNEL);

		if (!buf)

			return -ENOMEM;

		cmd = buf;

	} else {

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

	}

	if (xe_gt_WARN_ON(lrc->gt, max_len < 12))

		return -ENOSPC;



	*cmd++ = MI_STORE_REGISTER_MEM | MI_SRM_USE_GGTT | MI_SRM_ADD_CS_OFFSET;

	*cmd++ = ENGINE_ID(0).addr;
@@ -971,6 +965,49 @@ static int xe_lrc_setup_utilization(struct xe_lrc *lrc) 
		*cmd++ = upper_32_bits(CONTEXT_ACTIVE);

	}



	return cmd - batch;

}



struct wa_bb_setup {

	ssize_t (*setup)(struct xe_lrc *lrc, struct xe_hw_engine *hwe,

			 u32 *batch, size_t max_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;

	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) {

		buf = kmalloc(max_size, GFP_KERNEL);

		if (!buf)

			return -ENOMEM;

		cmd = buf;

	} else {

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

	}



	remain = max_size / sizeof(*cmd);



	for (size_t i = 0; i < ARRAY_SIZE(funcs); i++) {

		ssize_t len = funcs[i].setup(lrc, hwe, cmd, remain);



		remain -= len;



		/*

		 * There should always be at least 1 additional dword for

		 * the end marker

		 */

		if (len < 0 || xe_gt_WARN_ON(lrc->gt, remain < 1))

			goto fail;



		cmd += len;

	}



	*cmd++ = MI_BATCH_BUFFER_END;



	if (buf) {
@@ -983,6 +1020,10 @@ static int xe_lrc_setup_utilization(struct xe_lrc *lrc) 
			     xe_bo_ggtt_addr(lrc->bb_per_ctx_bo) | 1);



	return 0;



fail:

	kfree(buf);

	return -ENOSPC;

}



#define PVC_CTX_ASID		(0x2e + 1)
@@ -1139,7 +1180,7 @@ 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);



	err = xe_lrc_setup_utilization(lrc);

	err = setup_wa_bb(lrc, hwe);

	if (err)

		goto err_lrc_finish;