[PATCH 11/13] drm/xe/pf: Use GuC Buffer Cache during VFs provisioning

[Matthew Brost]

On Thu, Dec 12, 2024 at 02:01:39AM +0100, Michal Wajdeczko wrote:
> Start using GuC buffer cache for the VF's configuration actions.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> ---
> v2: rebased (Michal)
> ---
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c | 69 +++++++++++-----------
>  1 file changed, 36 insertions(+), 33 deletions(-)
> 
> 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 65082f12f1a8..8f756f81bc20 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> @@ -20,6 +20,7 @@
>  #include "xe_gt_sriov_pf_policy.h"
>  #include "xe_gt_sriov_printk.h"
>  #include "xe_guc.h"
> +#include "xe_guc_buf.h"
>  #include "xe_guc_ct.h"
>  #include "xe_guc_db_mgr.h"
>  #include "xe_guc_fwif.h"
> @@ -71,48 +72,27 @@ static int pf_send_vf_cfg_reset(struct xe_gt *gt, u32 vfid)
>   * Return: number of KLVs that were successfully parsed and saved,
>   *         negative error code on failure.
>   */
> -static int pf_send_vf_cfg_klvs(struct xe_gt *gt, u32 vfid, const u32 *klvs, u32 num_dwords)
> +static int pf_send_vf_buf_klvs(struct xe_gt *gt, u32 vfid, struct xe_guc_buf buf, u32 num_dwords)
>  {
> -	const u32 bytes = num_dwords * sizeof(u32);
> -	struct xe_tile *tile = gt_to_tile(gt);
> -	struct xe_device *xe = tile_to_xe(tile);
>  	struct xe_guc *guc = &gt->uc.guc;
> -	struct xe_bo *bo;
> -	int ret;
>  
> -	bo = xe_bo_create_pin_map(xe, tile, NULL,
> -				  ALIGN(bytes, PAGE_SIZE),
> -				  ttm_bo_type_kernel,
> -				  XE_BO_FLAG_VRAM_IF_DGFX(tile) |
> -				  XE_BO_FLAG_GGTT |
> -				  XE_BO_FLAG_GGTT_INVALIDATE);
> -	if (IS_ERR(bo))
> -		return PTR_ERR(bo);
> -
> -	xe_map_memcpy_to(xe, &bo->vmap, 0, klvs, bytes);
> -
> -	ret = guc_action_update_vf_cfg(guc, vfid, xe_bo_ggtt_addr(bo), num_dwords);
> -
> -	xe_bo_unpin_map_no_vm(bo);
> -
> -	return ret;
> +	return guc_action_update_vf_cfg(guc, vfid, xe_guc_buf_gpu_addr(buf), num_dwords);
>  }
>  
>  /*
>   * Return: 0 on success, -ENOKEY if some KLVs were not updated, -EPROTO if reply was malformed,
>   *         negative error code on failure.
>   */
> -static int pf_push_vf_cfg_klvs(struct xe_gt *gt, unsigned int vfid, u32 num_klvs,
> -			       const u32 *klvs, u32 num_dwords)
> +static int pf_push_vf_buf_klvs(struct xe_gt *gt, unsigned int vfid, u32 num_klvs,
> +			       struct xe_guc_buf buf, u32 num_dwords)
>  {
>  	int ret;
>  
> -	xe_gt_assert(gt, num_klvs == xe_guc_klv_count(klvs, num_dwords));
> -
> -	ret = pf_send_vf_cfg_klvs(gt, vfid, klvs, num_dwords);
> +	ret = pf_send_vf_buf_klvs(gt, vfid, buf, num_dwords);
>  
>  	if (ret != num_klvs) {
>  		int err = ret < 0 ? ret : ret < num_klvs ? -ENOKEY : -EPROTO;
> +		void *klvs = xe_guc_buf_cpu_ptr(buf);
>  		struct drm_printer p = xe_gt_info_printer(gt);
>  		char name[8];
>  
> @@ -125,13 +105,35 @@ static int pf_push_vf_cfg_klvs(struct xe_gt *gt, unsigned int vfid, u32 num_klvs
>  
>  	if (IS_ENABLED(CONFIG_DRM_XE_DEBUG_SRIOV)) {
>  		struct drm_printer p = xe_gt_info_printer(gt);
> +		void *klvs = xe_guc_buf_cpu_ptr(buf);
> +		char name[8];
>  
> +		xe_gt_sriov_info(gt, "pushed %s config with %u KLV%s:\n",
> +				 xe_sriov_function_name(vfid, name, sizeof(name)),
> +				 num_klvs, str_plural(num_klvs));
>  		xe_guc_klv_print(klvs, num_dwords, &p);
>  	}
>  
>  	return 0;
>  }
>  
> +/*
> + * Return: 0 on success, -ENOBUFS if no free buffer for the indirect data,
> + *         negative error code on failure.
> + */
> +static int pf_push_vf_cfg_klvs(struct xe_gt *gt, unsigned int vfid, u32 num_klvs,
> +			       const u32 *klvs, u32 num_dwords)
> +{
> +	CLASS(xe_guc_buf_from_data, buf)(&gt->uc.guc.buf, klvs, num_dwords * sizeof(u32));
> +
> +	xe_gt_assert(gt, num_klvs == xe_guc_klv_count(klvs, num_dwords));
> +
> +	if (!xe_guc_buf_is_valid(buf))
> +		return -ENOBUFS;
> +
> +	return pf_push_vf_buf_klvs(gt, vfid, num_klvs, buf, num_dwords);
> +}
> +
>  static int pf_push_vf_cfg_u32(struct xe_gt *gt, unsigned int vfid, u16 key, u32 value)
>  {
>  	u32 klv[] = {
> @@ -304,16 +306,17 @@ static u32 encode_config(u32 *cfg, const struct xe_gt_sriov_config *config, bool
>  static int pf_push_full_vf_config(struct xe_gt *gt, unsigned int vfid)
>  {
>  	struct xe_gt_sriov_config *config = pf_pick_vf_config(gt, vfid);
> -	u32 max_cfg_dwords = SZ_4K / sizeof(u32);
> +	u32 max_cfg_dwords = xe_guc_buf_cache_dwords(&gt->uc.guc.buf);
> +	CLASS(xe_guc_buf, buf)(&gt->uc.guc.buf, max_cfg_dwords);
>  	u32 num_dwords;
>  	int num_klvs;
>  	u32 *cfg;
>  	int err;
>  
> -	cfg = kcalloc(max_cfg_dwords, sizeof(u32), GFP_KERNEL);
> -	if (!cfg)
> -		return -ENOMEM;
> +	if (!xe_guc_buf_is_valid(buf))
> +		return -ENOBUFS;
>  
> +	cfg = xe_guc_buf_cpu_ptr(buf);
>  	num_dwords = encode_config(cfg, config, true);
>  	xe_gt_assert(gt, num_dwords <= max_cfg_dwords);
>  
> @@ -328,11 +331,11 @@ static int pf_push_full_vf_config(struct xe_gt *gt, unsigned int vfid)
>  		num_dwords += encode_config_ggtt(cfg + num_dwords, other, true);
>  	}
>  	xe_gt_assert(gt, num_dwords <= max_cfg_dwords);
> +	xe_guc_buf_flush(buf);

Nit: It doesn't look like the return of xe_guc_buf_flush is ever used, maybe drop it.

Matt

>  
>  	num_klvs = xe_guc_klv_count(cfg, num_dwords);
> -	err = pf_push_vf_cfg_klvs(gt, vfid, num_klvs, cfg, num_dwords);
> +	err = pf_push_vf_buf_klvs(gt, vfid, num_klvs, buf, num_dwords);
>  
> -	kfree(cfg);
>  	return err;
>  }
>  
> -- 
> 2.47.1
>