Re: [Intel-xe] [PATCH] drm/xe: Implement HW workaround 14016763929

["Welty, Brian" <brian.welty@intel.com>]

On 8/4/2023 1:44 PM, Oak Zeng wrote:
> To workaround a HW bug on DG2, driver is required to map the whole
> ppgtt virtual address space before GPU workload submission. Thus
> set the XE_VM_FLAG_SCRATCH_PAGE flag during vm create so the whole
> address space is mapped to point to scratch page.
> 
> v1:
>    - Move the workaround implementation from xe_vm_create to
>      xe_vm_create_ioctl - Brian
>    - Reorder error checking in xe_vm_create_ioctl - Jose
>    - Implement WA only for DG2-G10 and DG2-G12


Reviewed-by: Brian Welty <brian.welty@intel.com>


> 
> Signed-off-by: Oak Zeng <oak.zeng@intel.com>
> ---
>   drivers/gpu/drm/xe/Makefile        |  2 +-
>   drivers/gpu/drm/xe/xe_vm.c         | 13 +++++++++----
>   drivers/gpu/drm/xe/xe_wa_oob.rules |  2 ++
>   3 files changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> index 1b59702cd9f9..c91bb7ddcf1d 100644
> --- a/drivers/gpu/drm/xe/Makefile
> +++ b/drivers/gpu/drm/xe/Makefile
> @@ -37,7 +37,7 @@ quiet_cmd_wa_oob = GEN     $(notdir $(generated_oob))
>   $(generated_oob) &: $(obj)/xe_gen_wa_oob $(srctree)/$(src)/xe_wa_oob.rules
>   	$(call cmd,wa_oob)
>   
> -$(obj)/xe_guc.o $(obj)/xe_wa.o $(obj)/xe_ring_ops.o: $(generated_oob)
> +$(obj)/xe_guc.o $(obj)/xe_wa.o $(obj)/xe_ring_ops.o $(obj)/xe_vm.o: $(generated_oob)
>   
>   # Please keep these build lists sorted!
>   
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index cb28dbc2bdbb..394bd23dc18e 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -29,6 +29,8 @@
>   #include "xe_res_cursor.h"
>   #include "xe_sync.h"
>   #include "xe_trace.h"
> +#include "generated/xe_wa_oob.h"
> +#include "xe_wa.h"
>   
>   #define TEST_VM_ASYNC_OPS_ERROR
>   
> @@ -1982,6 +1984,13 @@ int xe_vm_create_ioctl(struct drm_device *dev, void *data,
>   	int err;
>   	u32 flags = 0;
>   
> +	if (XE_WA(xe_root_mmio_gt(xe), 14016763929))
> +		args->flags |= DRM_XE_VM_CREATE_SCRATCH_PAGE;
> +
> +	if (XE_IOCTL_DBG(xe, args->flags & DRM_XE_VM_CREATE_FAULT_MODE &&
> +			 !xe->info.supports_usm))
> +		return -EINVAL;
> +
>   	if (XE_IOCTL_DBG(xe, args->reserved[0] || args->reserved[1]))
>   		return -EINVAL;
>   
> @@ -2004,10 +2013,6 @@ int xe_vm_create_ioctl(struct drm_device *dev, void *data,
>   			 xe_device_in_fault_mode(xe)))
>   		return -EINVAL;
>   
> -	if (XE_IOCTL_DBG(xe, args->flags & DRM_XE_VM_CREATE_FAULT_MODE &&
> -			 !xe->info.supports_usm))
> -		return -EINVAL;
> -
>   	if (args->flags & DRM_XE_VM_CREATE_SCRATCH_PAGE)
>   		flags |= XE_VM_FLAG_SCRATCH_PAGE;
>   	if (args->flags & DRM_XE_VM_CREATE_COMPUTE_MODE)
> diff --git a/drivers/gpu/drm/xe/xe_wa_oob.rules b/drivers/gpu/drm/xe/xe_wa_oob.rules
> index 15c23813398a..ea90dcc933b5 100644
> --- a/drivers/gpu/drm/xe/xe_wa_oob.rules
> +++ b/drivers/gpu/drm/xe/xe_wa_oob.rules
> @@ -15,3 +15,5 @@
>   18020744125	PLATFORM(PVC)
>   1509372804	PLATFORM(PVC), GRAPHICS_STEP(A0, C0)
>   1409600907	GRAPHICS_VERSION_RANGE(1200, 1250)
> +14016763929	SUBPLATFORM(DG2, G10)
> +		SUBPLATFORM(DG2, G12)