[Intel-gfx] [PATCH v3 07/14] drm/i915/guc: Move firmware size check out of generic code

[Michal Wajdeczko]

On Fri, 13 Oct 2017 08:49:22 +0200, Sagar Arun Kamble  
<sagar.a.kamble at intel.com> wrote:

>
>
> On 10/13/2017 4:24 AM, Michal Wajdeczko wrote:
>> Checking GuC firmware size can be done in GuC specific code
>> right before DMA copy as it is unlikely to fail anyway.
>>
>> v2: rebased
>>
>> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
>> Cc: Sagar Arun Kamble <sagar.a.kamble at intel.com>
>> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>> Reviewed-by: Sagar Arun Kamble <sagar.a.kamble at intel.com> #1
>> ---
>>   drivers/gpu/drm/i915/intel_guc_fw.c | 7 ++++++-
>>   drivers/gpu/drm/i915/intel_uc_fw.c  | 8 --------
>>   2 files changed, 6 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_guc_fw.c  
>> b/drivers/gpu/drm/i915/intel_guc_fw.c
>> index 71dacc3..020ce26 100644
>> --- a/drivers/gpu/drm/i915/intel_guc_fw.c
>> +++ b/drivers/gpu/drm/i915/intel_guc_fw.c
>> @@ -133,6 +133,7 @@ static int guc_ucode_xfer_dma(struct  
>> drm_i915_private *dev_priv,
>>   	unsigned long offset;
>>   	struct sg_table *sg = vma->pages;
>>   	u32 status, rsa[UOS_RSA_SCRATCH_MAX_COUNT];
>> +	u32 size = guc_fw->header_size + guc_fw->ucode_size;
>>   	int i, ret = 0;
>>     	/* where RSA signature starts */
>> @@ -145,7 +146,11 @@ static int guc_ucode_xfer_dma(struct  
>> drm_i915_private *dev_priv,
>>     	/* The header plus uCode will be copied to WOPCM via DMA,  
>> excluding any
>>   	 * other components */
>> -	I915_WRITE(DMA_COPY_SIZE, guc_fw->header_size + guc_fw->ucode_size);
>> +	if (size > intel_guc_wopcm_size(dev_priv)) {
> This size check better be done before RSA copy. With that:
> Reviewed-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>

Hmm, I was planning to separate handling of RSA signature out of
this function and focus here only on DMA xfer, so that move will
be void. And I still think that size check is better to be done
closer to the place where that size will be used in HW commands.

Michal


>> +		DRM_ERROR("Firmware is too large to fit in WOPCM\n");
>> +		return -EFBIG;
>> +	}
>> +	I915_WRITE(DMA_COPY_SIZE, size);
>>     	/* Set the source address for the new blob */
>>   	offset = guc_ggtt_offset(vma) + guc_fw->header_offset;
>> diff --git a/drivers/gpu/drm/i915/intel_uc_fw.c  
>> b/drivers/gpu/drm/i915/intel_uc_fw.c
>> index 766b1cb..482115b 100644
>> --- a/drivers/gpu/drm/i915/intel_uc_fw.c
>> +++ b/drivers/gpu/drm/i915/intel_uc_fw.c
>> @@ -108,14 +108,6 @@ void intel_uc_fw_fetch(struct drm_i915_private  
>> *dev_priv,
>>   	 */
>>   	switch (uc_fw->type) {
>>   	case INTEL_UC_FW_TYPE_GUC:
>> -		/* Header and uCode will be loaded to WOPCM. Size of the two. */
>> -		size = uc_fw->header_size + uc_fw->ucode_size;
>> -
>> -		/* Top 32k of WOPCM is reserved (8K stack + 24k RC6 context). */
>> -		if (size > intel_guc_wopcm_size(dev_priv)) {
>> -			DRM_ERROR("Firmware is too large to fit in WOPCM\n");
>> -			goto fail;
>> -		}
>>   		uc_fw->major_ver_found = css->guc.sw_version >> 16;
>>   		uc_fw->minor_ver_found = css->guc.sw_version & 0xFFFF;
>>   		break;