[PATCHv2] drm/amdgpu: Update invalid PTE flag setting

[Felix Kuehling]

Am 2023-06-12 um 12:23 schrieb Mukul Joshi:
> Update the invalid PTE flag setting with TF enabled.
> This is to ensure, in addition to transitioning the
> retry fault to a no-retry fault, it also causes the
> wavefront to enter the trap handler. With the current
> setting, the fault only transitions to a no-retry fault.
> Additionally, have 2 sets of invalid PTE settings, one for
> TF enabled, the other for TF disabled. The setting with
> TF disabled, doesn't work with TF enabled.
>
> Signed-off-by: Mukul Joshi <mukul.joshi at amd.com>
> ---
> v1->v2:
> - Update handling according to Christian's feedback.
>
>   drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h   |  7 +++++++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c    |  2 +-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h    |  6 ++++++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c |  3 +++
>   drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c     | 11 +++++++++++
>   5 files changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> index 6794edd1d2d2..e5c6b075fbbb 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> @@ -152,6 +152,10 @@ struct amdgpu_gmc_funcs {
>   	void (*override_vm_pte_flags)(struct amdgpu_device *dev,
>   				      struct amdgpu_vm *vm,
>   				      uint64_t addr, uint64_t *flags);
> +	/* update no-retry flags */
> +	void (*update_vm_pte_noretry_flags)(struct amdgpu_device *dev,
> +					uint64_t *flags);
> +
>   	/* get the amount of memory used by the vbios for pre-OS console */
>   	unsigned int (*get_vbios_fb_size)(struct amdgpu_device *adev);
>   
> @@ -343,6 +347,9 @@ struct amdgpu_gmc {
>   #define amdgpu_gmc_override_vm_pte_flags(adev, vm, addr, pte_flags)	\
>   	(adev)->gmc.gmc_funcs->override_vm_pte_flags			\
>   		((adev), (vm), (addr), (pte_flags))
> +#define amdgpu_gmc_update_vm_pte_noretry_flags(adev, pte_flags)		\
> +	((adev)->gmc.gmc_funcs->update_vm_pte_noretry_flags		\
> +		((adev), (pte_flags)))
>   #define amdgpu_gmc_get_vbios_fb_size(adev) (adev)->gmc.gmc_funcs->get_vbios_fb_size((adev))
>   
>   /**
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 1cb14ea18cd9..ff9db7e5c086 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -2583,7 +2583,7 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, u32 pasid,
>   		/* Intentionally setting invalid PTE flag
>   		 * combination to force a no-retry-fault
>   		 */
> -		flags = AMDGPU_PTE_SNOOPED | AMDGPU_PTE_PRT;
> +		flags = AMDGPU_VM_NORETRY_FLAGS;
>   		value = 0;
>   	} else if (amdgpu_vm_fault_stop == AMDGPU_VM_FAULT_STOP_NEVER) {
>   		/* Redirect the access to the dummy page */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> index 9c85d494f2a2..b81fcb962d8f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> @@ -84,7 +84,13 @@ struct amdgpu_mem_stats;
>   /* PDE Block Fragment Size for VEGA10 */
>   #define AMDGPU_PDE_BFS(a)	((uint64_t)a << 59)
>   
> +/* Flag combination to set no-retry with TF disabled */
> +#define AMDGPU_VM_NORETRY_FLAGS	(AMDGPU_PTE_EXECUTABLE | AMDGPU_PDE_PTE | \
> +				AMDGPU_PTE_TF)
>   
> +/* Flag combination to set no-retry with TF enabled */
> +#define AMDGPU_VM_NORETRY_FLAGS_TF (AMDGPU_PTE_VALID | AMDGPU_PTE_SYSTEM | \
> +				   AMDGPU_PTE_PRT)
>   /* For GFX9 */
>   #define AMDGPU_PTE_MTYPE_VG10(a)	((uint64_t)(a) << 57)
>   #define AMDGPU_PTE_MTYPE_VG10_MASK	AMDGPU_PTE_MTYPE_VG10(3ULL)
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
> index dea1a64be44d..39f1650f6d00 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
> @@ -804,6 +804,9 @@ static void amdgpu_vm_pte_update_flags(struct amdgpu_vm_update_params *params,
>   		flags |= AMDGPU_PTE_EXECUTABLE;
>   	}
>   
> +	if (adev->gmc.translate_further && level == AMDGPU_VM_PTB)
> +		amdgpu_gmc_update_vm_pte_noretry_flags(adev, &flags);

Don't you need a check that 
((adev)->gmc.gmc_funcs->update_vm_pte_noretry_flags is not NULL? But 
adding a new callback for this may be overkill. Since the 
AMDGPU_VM_NORETRY_FLAGS(_TF) are defined in a non-HW-specific header 
file, you can probably implement the application of those flags in 
amdgpu_vm_pte_update_flags directly.

Regards,
   Felix


> +
>   	/* APUs mapping system memory may need different MTYPEs on different
>   	 * NUMA nodes. Only do this for contiguous ranges that can be assumed
>   	 * to be on the same NUMA node.
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> index 3ed286b72cae..aea8e80c3419 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> @@ -1307,6 +1307,16 @@ static void gmc_v9_0_get_vm_pte(struct amdgpu_device *adev,
>   					     mapping, flags);
>   }
>   
> +static void gmc_v9_0_update_vm_pte_noretry_flags(struct amdgpu_device *adev,
> +					   uint64_t *flags)
> +{
> +	/* Update no retry flags when TF is enabled */
> +	if ((*flags & AMDGPU_VM_NORETRY_FLAGS) == AMDGPU_VM_NORETRY_FLAGS) {
> +		*flags &= ~AMDGPU_VM_NORETRY_FLAGS;
> +		*flags |= AMDGPU_VM_NORETRY_FLAGS_TF;
> +	}
> +}
> +
>   static void gmc_v9_0_override_vm_pte_flags(struct amdgpu_device *adev,
>   					   struct amdgpu_vm *vm,
>   					   uint64_t addr, uint64_t *flags)
> @@ -1445,6 +1455,7 @@ static const struct amdgpu_gmc_funcs gmc_v9_0_gmc_funcs = {
>   	.get_vm_pde = gmc_v9_0_get_vm_pde,
>   	.get_vm_pte = gmc_v9_0_get_vm_pte,
>   	.override_vm_pte_flags = gmc_v9_0_override_vm_pte_flags,
> +	.update_vm_pte_noretry_flags = gmc_v9_0_update_vm_pte_noretry_flags,
>   	.get_vbios_fb_size = gmc_v9_0_get_vbios_fb_size,
>   	.query_mem_partition_mode = &gmc_v9_0_query_memory_partition,
>   };