[RFC PATCH 24/97] drm/i915/guc: Add flag for mark broken CTB

[Matthew Brost]

On Thu, May 06, 2021 at 12:13:38PM -0700, Matthew Brost wrote:
> From: Michal Wajdeczko <michal.wajdeczko at intel.com>
> 
> Once CTB descriptor is found in error state, either set by GuC
> or us, there is no need continue checking descriptor any more,
> we can rely on our internal flag.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>

Reviewed-by: Matthew Brost <matthew.brost at intel.com>

> Cc: Piotr Piórkowski <piotr.piorkowski at intel.com>
> ---
>  drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 13 +++++++++++--
>  drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h |  2 ++
>  2 files changed, 13 insertions(+), 2 deletions(-)
> 
> 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 1afdeac683b5..178f73ab2c96 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> @@ -123,6 +123,7 @@ static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc,
>  
>  static void guc_ct_buffer_reset(struct intel_guc_ct_buffer *ctb, u32 cmds_addr)
>  {
> +	ctb->broken = false;
>  	guc_ct_buffer_desc_init(ctb->desc, cmds_addr, ctb->size);
>  }
>  
> @@ -365,9 +366,12 @@ static int ct_write(struct intel_guc_ct *ct,
>  	u32 *cmds = ctb->cmds;
>  	unsigned int i;
>  
> -	if (unlikely(desc->is_in_error))
> +	if (unlikely(ctb->broken))
>  		return -EPIPE;
>  
> +	if (unlikely(desc->is_in_error))
> +		goto corrupted;
> +
>  	if (unlikely(!IS_ALIGNED(head | tail, 4) ||
>  		     (tail | head) >= size))
>  		goto corrupted;
> @@ -423,6 +427,7 @@ static int ct_write(struct intel_guc_ct *ct,
>  	CT_ERROR(ct, "Corrupted descriptor addr=%#x head=%u tail=%u size=%u\n",
>  		 desc->addr, desc->head, desc->tail, desc->size);
>  	desc->is_in_error = 1;
> +	ctb->broken = true;
>  	return -EPIPE;
>  }
>  
> @@ -608,9 +613,12 @@ static int ct_read(struct intel_guc_ct *ct, struct ct_incoming_msg **msg)
>  	unsigned int i;
>  	u32 header;
>  
> -	if (unlikely(desc->is_in_error))
> +	if (unlikely(ctb->broken))
>  		return -EPIPE;
>  
> +	if (unlikely(desc->is_in_error))
> +		goto corrupted;
> +
>  	if (unlikely(!IS_ALIGNED(head | tail, 4) ||
>  		     (tail | head) >= size))
>  		goto corrupted;
> @@ -674,6 +682,7 @@ static int ct_read(struct intel_guc_ct *ct, struct ct_incoming_msg **msg)
>  	CT_ERROR(ct, "Corrupted descriptor addr=%#x head=%u tail=%u size=%u\n",
>  		 desc->addr, desc->head, desc->tail, desc->size);
>  	desc->is_in_error = 1;
> +	ctb->broken = true;
>  	return -EPIPE;
>  }
>  
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
> index cb222f202301..7d3cd375d6a7 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
> @@ -32,12 +32,14 @@ struct intel_guc;
>   * @desc: pointer to the buffer descriptor
>   * @cmds: pointer to the commands buffer
>   * @size: size of the commands buffer
> + * @broken: flag to indicate if descriptor data is broken
>   */
>  struct intel_guc_ct_buffer {
>  	spinlock_t lock;
>  	struct guc_ct_buffer_desc *desc;
>  	u32 *cmds;
>  	u32 size;
> +	bool broken;
>  };
>  
>  
> -- 
> 2.28.0
>