On Thu, May 06, 2021 at 12:13:23PM -0700, Matthew Brost wrote:
> From: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx>
>
> Stop using fence/status from CTB descriptor as future GuC ABI will
> no longer support replies over CTB descriptor.
>
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx>
> Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
Reviewed-by: Matthew Brost <matthew.brost@xxxxxxxxx>
> ---
> .../gt/uc/abi/guc_communication_ctb_abi.h | 4 +-
> drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 72 ++-----------------
> 2 files changed, 6 insertions(+), 70 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h
> index ebd8c3e0e4bb..d38935f47ecf 100644
> --- a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h
> +++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h
> @@ -71,8 +71,8 @@ struct guc_ct_buffer_desc {
> u32 head; /* offset updated by GuC*/
> u32 tail; /* offset updated by owner */
> u32 is_in_error; /* error indicator */
> - u32 fence; /* fence updated by GuC */
> - u32 status; /* status updated by GuC */
> + u32 reserved1;
> + u32 reserved2;
> u32 owner; /* id of the channel owner */
> u32 owner_sub_id; /* owner-defined field for extra tracking */
> u32 reserved[5];
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> index 25618649048f..4cc8c0b71699 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> @@ -90,13 +90,6 @@ static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc,
> desc->owner = CTB_OWNER_HOST;
> }
>
> -static void guc_ct_buffer_desc_reset(struct guc_ct_buffer_desc *desc)
> -{
> - desc->head = 0;
> - desc->tail = 0;
> - desc->is_in_error = 0;
> -}
> -
> static int guc_action_register_ct_buffer(struct intel_guc *guc,
> u32 desc_addr,
> u32 type)
> @@ -315,8 +308,7 @@ static u32 ct_get_next_fence(struct intel_guc_ct *ct)
> static int ct_write(struct intel_guc_ct *ct,
> const u32 *action,
> u32 len /* in dwords */,
> - u32 fence,
> - bool want_response)
> + u32 fence)
> {
> struct intel_guc_ct_buffer *ctb = &ct->ctbs[CTB_SEND];
> struct guc_ct_buffer_desc *desc = ctb->desc;
> @@ -360,8 +352,7 @@ static int ct_write(struct intel_guc_ct *ct,
> * DW2+: action data
> */
> header = (len << GUC_CT_MSG_LEN_SHIFT) |
> - (GUC_CT_MSG_WRITE_FENCE_TO_DESC) |
> - (want_response ? GUC_CT_MSG_SEND_STATUS : 0) |
> + GUC_CT_MSG_SEND_STATUS |
> (action[0] << GUC_CT_MSG_ACTION_SHIFT);
>
> CT_DEBUG(ct, "writing %*ph %*ph %*ph\n",
> @@ -390,56 +381,6 @@ static int ct_write(struct intel_guc_ct *ct,
> return -EPIPE;
> }
>
> -/**
> - * wait_for_ctb_desc_update - Wait for the CT buffer descriptor update.
> - * @desc: buffer descriptor
> - * @fence: response fence
> - * @status: placeholder for status
> - *
> - * Guc will update CT buffer descriptor with new fence and status
> - * after processing the command identified by the fence. Wait for
> - * specified fence and then read from the descriptor status of the
> - * command.
> - *
> - * Return:
> - * * 0 response received (status is valid)
> - * * -ETIMEDOUT no response within hardcoded timeout
> - * * -EPROTO no response, CT buffer is in error
> - */
> -static int wait_for_ctb_desc_update(struct guc_ct_buffer_desc *desc,
> - u32 fence,
> - u32 *status)
> -{
> - int err;
> -
> - /*
> - * Fast commands should complete in less than 10us, so sample quickly
> - * up to that length of time, then switch to a slower sleep-wait loop.
> - * No GuC command should ever take longer than 10ms.
> - */
> -#define done (READ_ONCE(desc->fence) == fence)
> - err = wait_for_us(done, 10);
> - if (err)
> - err = wait_for(done, 10);
> -#undef done
> -
> - if (unlikely(err)) {
> - DRM_ERROR("CT: fence %u failed; reported fence=%u\n",
> - fence, desc->fence);
> -
> - if (WARN_ON(desc->is_in_error)) {
> - /* Something went wrong with the messaging, try to reset
> - * the buffer and hope for the best
> - */
> - guc_ct_buffer_desc_reset(desc);
> - err = -EPROTO;
> - }
> - }
> -
> - *status = desc->status;
> - return err;
> -}
> -
> /**
> * wait_for_ct_request_update - Wait for CT request state update.
> * @req: pointer to pending request
> @@ -483,8 +424,6 @@ static int ct_send(struct intel_guc_ct *ct,
> u32 response_buf_size,
> u32 *status)
> {
> - struct intel_guc_ct_buffer *ctb = &ct->ctbs[CTB_SEND];
> - struct guc_ct_buffer_desc *desc = ctb->desc;
> struct ct_request request;
> unsigned long flags;
> u32 fence;
> @@ -505,16 +444,13 @@ static int ct_send(struct intel_guc_ct *ct,
> list_add_tail(&request.link, &ct->requests.pending);
> spin_unlock_irqrestore(&ct->requests.lock, flags);
>
> - err = ct_write(ct, action, len, fence, !!response_buf);
> + err = ct_write(ct, action, len, fence);
> if (unlikely(err))
> goto unlink;
>
> intel_guc_notify(ct_to_guc(ct));
>
> - if (response_buf)
> - err = wait_for_ct_request_update(&request, status);
> - else
> - err = wait_for_ctb_desc_update(desc, fence, status);
> + err = wait_for_ct_request_update(&request, status);
> if (unlikely(err))
> goto unlink;
>
> --
> 2.28.0
>
