[PATCH 1/3] drm/xe/pf: Use GuC Buffer Cache during policy provisioning

[Cavitt, Jonathan]

-----Original Message-----
From: Intel-xe <intel-xe-bounces at lists.freedesktop.org> On Behalf Of Michal Wajdeczko
Sent: Wednesday, January 22, 2025 1:50 PM
To: intel-xe at lists.freedesktop.org
Cc: Wajdeczko, Michal <Michal.Wajdeczko at intel.com>; Thomas Hellström <thomas.hellstrom at linux.intel.com>
Subject: [PATCH 1/3] drm/xe/pf: Use GuC Buffer Cache during policy provisioning
> 
> Start using GuC buffer cache for the SRIOV policy configuration
> actions. This is a required step before we could declare SRIOV
> PF as being a reclaim safe.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>

LGTM, though I have to wonder if the pf_send_policy_klvs helper function
is particularly necessary now that it's been mostly gutted.
Reviewed-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
-Jonathan Cavitt

> ---
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_policy.c | 50 +++++++++++-----------
>  1 file changed, 24 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_policy.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_policy.c
> index c00fb354705f..4445f660e6d1 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_policy.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_policy.c
> @@ -10,6 +10,7 @@
>  #include "xe_gt_sriov_pf_helpers.h"
>  #include "xe_gt_sriov_pf_policy.h"
>  #include "xe_gt_sriov_printk.h"
> +#include "xe_guc_buf.h"
>  #include "xe_guc_ct.h"
>  #include "xe_guc_klv_helpers.h"
>  #include "xe_pm.h"
> @@ -34,48 +35,28 @@ static int guc_action_update_vgt_policy(struct xe_guc *guc, u64 addr, u32 size)
>   * Return: number of KLVs that were successfully parsed and saved,
>   *         negative error code on failure.
>   */
> -static int pf_send_policy_klvs(struct xe_gt *gt, const u32 *klvs, u32 num_dwords)
> +static int pf_send_policy_klvs(struct xe_gt *gt, 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);
> -	if (IS_ERR(bo))
> -		return PTR_ERR(bo);
> -
> -	xe_map_memcpy_to(xe, &bo->vmap, 0, klvs, bytes);
> -
> -	ret = guc_action_update_vgt_policy(guc, xe_bo_ggtt_addr(bo), num_dwords);
> -
> -	xe_bo_unpin_map_no_vm(bo);
> -
> -	return ret;
> +	return guc_action_update_vgt_policy(guc, xe_guc_buf_flush(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_policy_klvs(struct xe_gt *gt, u32 num_klvs,
> -			       const u32 *klvs, u32 num_dwords)
> +static int pf_push_policy_buf_klvs(struct xe_gt *gt, 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_policy_klvs(gt, klvs, num_dwords);
> +	ret = pf_send_policy_klvs(gt, buf, num_dwords);
>  
>  	if (ret != num_klvs) {
>  		int err = ret < 0 ? ret : ret < num_klvs ? -ENOKEY : -EPROTO;
>  		struct drm_printer p = xe_gt_info_printer(gt);
> +		void *klvs = xe_guc_buf_cpu_ptr(buf);
>  
>  		xe_gt_sriov_notice(gt, "Failed to push %u policy KLV%s (%pe)\n",
>  				   num_klvs, str_plural(num_klvs), ERR_PTR(err));
> @@ -86,6 +67,23 @@ static int pf_push_policy_klvs(struct xe_gt *gt, u32 num_klvs,
>  	return 0;
>  }
>  
> +/*
> + * Return: 0 on success, -ENOBUFS if there is no free buffer for the indirect data,
> + *         negative error code on failure.
> + */
> +static int pf_push_policy_klvs(struct xe_gt *gt, 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_policy_buf_klvs(gt, num_klvs, buf, num_dwords);
> +}
> +
>  static int pf_push_policy_u32(struct xe_gt *gt, u16 key, u32 value)
>  {
>  	u32 klv[] = {
> -- 
> 2.47.1
> 
>