diff mbox series

[3/8] drm/i915/mtl: Add PTE encode function

Message ID 20230419230058.2659455-4-fei.yang@intel.com (mailing list archive)
State New, archived
Headers show
Series drm/i915/mtl: Define MOCS and PAT tables for MTL | expand

Commit Message

Yang, Fei April 19, 2023, 11 p.m. UTC
From: Fei Yang <fei.yang@intel.com>

PTE encode functions are platform dependent. This patch implements
PTE functions for MTL, and ensures the correct PTE encode function
is used by calling pte_encode function pointer instead of the
hardcoded gen8 version of PTE encode.

Signed-off-by: Fei Yang <fei.yang@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Acked-by: Nirmoy Das <nirmoy.das@intel.com>
---
 drivers/gpu/drm/i915/display/intel_dpt.c |  2 +-
 drivers/gpu/drm/i915/gt/gen8_ppgtt.c     | 45 ++++++++++++++++++++----
 drivers/gpu/drm/i915/gt/intel_ggtt.c     | 36 +++++++++++++++++--
 3 files changed, 72 insertions(+), 11 deletions(-)

Comments

Matt Roper April 20, 2023, 8:40 p.m. UTC | #1
On Wed, Apr 19, 2023 at 04:00:53PM -0700, fei.yang@intel.com wrote:
> From: Fei Yang <fei.yang@intel.com>
> 
> PTE encode functions are platform dependent. This patch implements
> PTE functions for MTL, and ensures the correct PTE encode function
> is used by calling pte_encode function pointer instead of the
> hardcoded gen8 version of PTE encode.
> 
> Signed-off-by: Fei Yang <fei.yang@intel.com>
> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
> Acked-by: Nirmoy Das <nirmoy.das@intel.com>

Bspec: 45015, 45040

> ---
>  drivers/gpu/drm/i915/display/intel_dpt.c |  2 +-
>  drivers/gpu/drm/i915/gt/gen8_ppgtt.c     | 45 ++++++++++++++++++++----
>  drivers/gpu/drm/i915/gt/intel_ggtt.c     | 36 +++++++++++++++++--
>  3 files changed, 72 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dpt.c b/drivers/gpu/drm/i915/display/intel_dpt.c
> index b8027392144d..c5eacfdba1a5 100644
> --- a/drivers/gpu/drm/i915/display/intel_dpt.c
> +++ b/drivers/gpu/drm/i915/display/intel_dpt.c
> @@ -300,7 +300,7 @@ intel_dpt_create(struct intel_framebuffer *fb)
>  	vm->vma_ops.bind_vma    = dpt_bind_vma;
>  	vm->vma_ops.unbind_vma  = dpt_unbind_vma;
>  
> -	vm->pte_encode = gen8_ggtt_pte_encode;
> +	vm->pte_encode = vm->gt->ggtt->vm.pte_encode;
>  
>  	dpt->obj = dpt_obj;
>  	dpt->obj->is_dpt = true;
> diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> index 4daaa6f55668..11b91e0453c8 100644
> --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> @@ -55,6 +55,34 @@ static u64 gen8_pte_encode(dma_addr_t addr,
>  	return pte;
>  }
>  
> +static u64 mtl_pte_encode(dma_addr_t addr,
> +			  enum i915_cache_level level,
> +			  u32 flags)
> +{
> +	gen8_pte_t pte = addr | GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
> +
> +	if (unlikely(flags & PTE_READ_ONLY))
> +		pte &= ~GEN8_PAGE_RW;
> +
> +	if (flags & PTE_LM)
> +		pte |= GEN12_PPGTT_PTE_LM | GEN12_PPGTT_PTE_NC;

GEN12_PPGTT_PTE_NC got defined in the previous patch as BIT(5).  But
according to bspec 45040, bit 5 is ignored in the PTE encoding.  What is
this trying to do?


Matt

> +
> +	switch (level) {
> +	case I915_CACHE_NONE:
> +		pte |= GEN12_PPGTT_PTE_PAT1;
> +		break;
> +	case I915_CACHE_LLC:
> +	case I915_CACHE_L3_LLC:
> +		pte |= GEN12_PPGTT_PTE_PAT0 | GEN12_PPGTT_PTE_PAT1;
> +		break;
> +	case I915_CACHE_WT:
> +		pte |= GEN12_PPGTT_PTE_PAT0;
> +		break;
> +	}
> +
> +	return pte;
> +}
> +
>  static void gen8_ppgtt_notify_vgt(struct i915_ppgtt *ppgtt, bool create)
>  {
>  	struct drm_i915_private *i915 = ppgtt->vm.i915;
> @@ -427,7 +455,7 @@ gen8_ppgtt_insert_pte(struct i915_ppgtt *ppgtt,
>  		      u32 flags)
>  {
>  	struct i915_page_directory *pd;
> -	const gen8_pte_t pte_encode = gen8_pte_encode(0, cache_level, flags);
> +	const gen8_pte_t pte_encode = ppgtt->vm.pte_encode(0, cache_level, flags);
>  	gen8_pte_t *vaddr;
>  
>  	pd = i915_pd_entry(pdp, gen8_pd_index(idx, 2));
> @@ -580,7 +608,7 @@ static void gen8_ppgtt_insert_huge(struct i915_address_space *vm,
>  				   enum i915_cache_level cache_level,
>  				   u32 flags)
>  {
> -	const gen8_pte_t pte_encode = gen8_pte_encode(0, cache_level, flags);
> +	const gen8_pte_t pte_encode = vm->pte_encode(0, cache_level, flags);
>  	unsigned int rem = sg_dma_len(iter->sg);
>  	u64 start = vma_res->start;
>  
> @@ -743,7 +771,7 @@ static void gen8_ppgtt_insert_entry(struct i915_address_space *vm,
>  	GEM_BUG_ON(pt->is_compact);
>  
>  	vaddr = px_vaddr(pt);
> -	vaddr[gen8_pd_index(idx, 0)] = gen8_pte_encode(addr, level, flags);
> +	vaddr[gen8_pd_index(idx, 0)] = vm->pte_encode(addr, level, flags);
>  	drm_clflush_virt_range(&vaddr[gen8_pd_index(idx, 0)], sizeof(*vaddr));
>  }
>  
> @@ -773,7 +801,7 @@ static void __xehpsdv_ppgtt_insert_entry_lm(struct i915_address_space *vm,
>  	}
>  
>  	vaddr = px_vaddr(pt);
> -	vaddr[gen8_pd_index(idx, 0) / 16] = gen8_pte_encode(addr, level, flags);
> +	vaddr[gen8_pd_index(idx, 0) / 16] = vm->pte_encode(addr, level, flags);
>  }
>  
>  static void xehpsdv_ppgtt_insert_entry(struct i915_address_space *vm,
> @@ -820,8 +848,8 @@ static int gen8_init_scratch(struct i915_address_space *vm)
>  		pte_flags |= PTE_LM;
>  
>  	vm->scratch[0]->encode =
> -		gen8_pte_encode(px_dma(vm->scratch[0]),
> -				I915_CACHE_NONE, pte_flags);
> +		vm->pte_encode(px_dma(vm->scratch[0]),
> +			       I915_CACHE_NONE, pte_flags);
>  
>  	for (i = 1; i <= vm->top; i++) {
>  		struct drm_i915_gem_object *obj;
> @@ -963,7 +991,10 @@ struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt,
>  	 */
>  	ppgtt->vm.alloc_scratch_dma = alloc_pt_dma;
>  
> -	ppgtt->vm.pte_encode = gen8_pte_encode;
> +	if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70))
> +		ppgtt->vm.pte_encode = mtl_pte_encode;
> +	else
> +		ppgtt->vm.pte_encode = gen8_pte_encode;
>  
>  	ppgtt->vm.bind_async_flags = I915_VMA_LOCAL_BIND;
>  	ppgtt->vm.insert_entries = gen8_ppgtt_insert;
> diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> index 3c7f1ed92f5b..20915edc8bd9 100644
> --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> @@ -220,6 +220,33 @@ static void guc_ggtt_invalidate(struct i915_ggtt *ggtt)
>  	}
>  }
>  
> +static u64 mtl_ggtt_pte_encode(dma_addr_t addr,
> +			       enum i915_cache_level level,
> +			       u32 flags)
> +{
> +	gen8_pte_t pte = addr | GEN8_PAGE_PRESENT;
> +
> +	WARN_ON_ONCE(addr & ~GEN12_GGTT_PTE_ADDR_MASK);
> +
> +	if (flags & PTE_LM)
> +		pte |= GEN12_GGTT_PTE_LM;
> +
> +	switch (level) {
> +	case I915_CACHE_NONE:
> +		pte |= MTL_GGTT_PTE_PAT1;
> +		break;
> +	case I915_CACHE_LLC:
> +	case I915_CACHE_L3_LLC:
> +		pte |= MTL_GGTT_PTE_PAT0 | MTL_GGTT_PTE_PAT1;
> +		break;
> +	case I915_CACHE_WT:
> +		pte |= MTL_GGTT_PTE_PAT0;
> +		break;
> +	}
> +
> +	return pte;
> +}
> +
>  u64 gen8_ggtt_pte_encode(dma_addr_t addr,
>  			 enum i915_cache_level level,
>  			 u32 flags)
> @@ -247,7 +274,7 @@ static void gen8_ggtt_insert_page(struct i915_address_space *vm,
>  	gen8_pte_t __iomem *pte =
>  		(gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>  
> -	gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, flags));
> +	gen8_set_pte(pte, ggtt->vm.pte_encode(addr, level, flags));
>  
>  	ggtt->invalidate(ggtt);
>  }
> @@ -257,8 +284,8 @@ static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
>  				     enum i915_cache_level level,
>  				     u32 flags)
>  {
> -	const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, flags);
>  	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> +	const gen8_pte_t pte_encode = ggtt->vm.pte_encode(0, level, flags);
>  	gen8_pte_t __iomem *gte;
>  	gen8_pte_t __iomem *end;
>  	struct sgt_iter iter;
> @@ -981,7 +1008,10 @@ static int gen8_gmch_probe(struct i915_ggtt *ggtt)
>  	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
>  	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
>  
> -	ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
> +	if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70))
> +		ggtt->vm.pte_encode = mtl_ggtt_pte_encode;
> +	else
> +		ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
>  
>  	return ggtt_probe_common(ggtt, size);
>  }
> -- 
> 2.25.1
>
Yang, Fei April 21, 2023, 5:27 p.m. UTC | #2
> On Wed, Apr 19, 2023 at 04:00:53PM -0700, fei.yang@intel.com wrote:
>> From: Fei Yang <fei.yang@intel.com>
>>
>> PTE encode functions are platform dependent. This patch implements
>> PTE functions for MTL, and ensures the correct PTE encode function
>> is used by calling pte_encode function pointer instead of the
>> hardcoded gen8 version of PTE encode.
>>
>> Signed-off-by: Fei Yang <fei.yang@intel.com>
>> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
>> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
>> Acked-by: Nirmoy Das <nirmoy.das@intel.com>
>
> Bspec: 45015, 45040
>
>> ---
>>  drivers/gpu/drm/i915/display/intel_dpt.c |  2 +-
>>  drivers/gpu/drm/i915/gt/gen8_ppgtt.c     | 45 ++++++++++++++++++++----
>>  drivers/gpu/drm/i915/gt/intel_ggtt.c     | 36 +++++++++++++++++--
>>  3 files changed, 72 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dpt.c b/drivers/gpu/drm/i915/display/intel_dpt.c
>> index b8027392144d..c5eacfdba1a5 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dpt.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dpt.c
>> @@ -300,7 +300,7 @@ intel_dpt_create(struct intel_framebuffer *fb)
>>        vm->vma_ops.bind_vma    = dpt_bind_vma;
>>        vm->vma_ops.unbind_vma  = dpt_unbind_vma;
>>
>> -     vm->pte_encode = gen8_ggtt_pte_encode;
>> +     vm->pte_encode = vm->gt->ggtt->vm.pte_encode;
>>
>>        dpt->obj = dpt_obj;
>>        dpt->obj->is_dpt = true;
>> diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>> index 4daaa6f55668..11b91e0453c8 100644
>> --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>> +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>> @@ -55,6 +55,34 @@ static u64 gen8_pte_encode(dma_addr_t addr,
>>        return pte;
>>  }
>>
>> +static u64 mtl_pte_encode(dma_addr_t addr,
>> +                       enum i915_cache_level level,
>> +                       u32 flags)
>> +{
>> +     gen8_pte_t pte = addr | GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
>> +
>> +     if (unlikely(flags & PTE_READ_ONLY))
>> +             pte &= ~GEN8_PAGE_RW;
>> +
>> +     if (flags & PTE_LM)
>> +             pte |= GEN12_PPGTT_PTE_LM | GEN12_PPGTT_PTE_NC;
>
> GEN12_PPGTT_PTE_NC got defined in the previous patch as BIT(5).  But
> according to bspec 45040, bit 5 is ignored in the PTE encoding.  What is
> this trying to do?

This takes effect only for PTE_LM, doesn't affect MTL.
PTE_NC is needed for PVC (use of access counter).

I believe this function was writen based on the one for PVC. And this function
did get extended to cover all gen12 in a later patch.

-Fei

> Matt
>
>> +
>> +     switch (level) {
>> +     case I915_CACHE_NONE:
>> +             pte |= GEN12_PPGTT_PTE_PAT1;
>> +             break;
Matt Roper April 21, 2023, 5:42 p.m. UTC | #3
On Fri, Apr 21, 2023 at 10:27:22AM -0700, Yang, Fei wrote:
>    > On Wed, Apr 19, 2023 at 04:00:53PM -0700, fei.yang@intel.com wrote:
>    >> From: Fei Yang <fei.yang@intel.com>
>    >>
>    >> PTE encode functions are platform dependent. This patch implements
>    >> PTE functions for MTL, and ensures the correct PTE encode function
>    >> is used by calling pte_encode function pointer instead of the
>    >> hardcoded gen8 version of PTE encode.
>    >>
>    >> Signed-off-by: Fei Yang <fei.yang@intel.com>
>    >> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
>    >> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
>    >> Acked-by: Nirmoy Das <nirmoy.das@intel.com>
>    >
>    > Bspec: 45015, 45040
>    >
>    >> ---
>    >>  drivers/gpu/drm/i915/display/intel_dpt.c |  2 +-
>    >>  drivers/gpu/drm/i915/gt/gen8_ppgtt.c     | 45 ++++++++++++++++++++----
>    >>  drivers/gpu/drm/i915/gt/intel_ggtt.c     | 36 +++++++++++++++++--
>    >>  3 files changed, 72 insertions(+), 11 deletions(-)
>    >>
>    >> diff --git a/drivers/gpu/drm/i915/display/intel_dpt.c
>    b/drivers/gpu/drm/i915/display/intel_dpt.c
>    >> index b8027392144d..c5eacfdba1a5 100644
>    >> --- a/drivers/gpu/drm/i915/display/intel_dpt.c
>    >> +++ b/drivers/gpu/drm/i915/display/intel_dpt.c
>    >> @@ -300,7 +300,7 @@ intel_dpt_create(struct intel_framebuffer *fb)
>    >>        vm->vma_ops.bind_vma    = dpt_bind_vma;
>    >>        vm->vma_ops.unbind_vma  = dpt_unbind_vma;
>    >>
>    >> -     vm->pte_encode = gen8_ggtt_pte_encode;
>    >> +     vm->pte_encode = vm->gt->ggtt->vm.pte_encode;
>    >>
>    >>        dpt->obj = dpt_obj;
>    >>        dpt->obj->is_dpt = true;
>    >> diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>    b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>    >> index 4daaa6f55668..11b91e0453c8 100644
>    >> --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>    >> +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>    >> @@ -55,6 +55,34 @@ static u64 gen8_pte_encode(dma_addr_t addr,
>    >>        return pte;
>    >>  }
>    >>
>    >> +static u64 mtl_pte_encode(dma_addr_t addr,
>    >> +                       enum i915_cache_level level,
>    >> +                       u32 flags)
>    >> +{
>    >> +     gen8_pte_t pte = addr | GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
>    >> +
>    >> +     if (unlikely(flags & PTE_READ_ONLY))
>    >> +             pte &= ~GEN8_PAGE_RW;
>    >> +
>    >> +     if (flags & PTE_LM)
>    >> +             pte |= GEN12_PPGTT_PTE_LM | GEN12_PPGTT_PTE_NC;
>    >
>    > GEN12_PPGTT_PTE_NC got defined in the previous patch as BIT(5).  But
>    > according to bspec 45040, bit 5 is ignored in the PTE encoding.  What is
>    > this trying to do?
>    This takes effect only for PTE_LM, doesn't affect MTL.
>    PTE_NC is needed for PVC (use of access counter).
>    I believe this function was writen based on the one for PVC. And this
>    function
>    did get extended to cover all gen12 in a later patch.

Even though MTL doesn't have local memory, PTE_LM is supposed to be used
on MTL for access to BAR2 stolen memory.


Matt

>    -Fei
>    > Matt
>    >
>    >> +
>    >> +     switch (level) {
>    >> +     case I915_CACHE_NONE:
>    >> +             pte |= GEN12_PPGTT_PTE_PAT1;
>    >> +             break;
Yang, Fei April 23, 2023, 7:37 a.m. UTC | #4
> On Fri, Apr 21, 2023 at 10:27:22AM -0700, Yang, Fei wrote:
>>> On Wed, Apr 19, 2023 at 04:00:53PM -0700, fei.yang@intel.com wrote:
>>>> From: Fei Yang <fei.yang@intel.com>
>>>>
>>>> PTE encode functions are platform dependent. This patch implements
>>>> PTE functions for MTL, and ensures the correct PTE encode function
>>>> is used by calling pte_encode function pointer instead of the
>>>> hardcoded gen8 version of PTE encode.
>>>>
>>>> Signed-off-by: Fei Yang <fei.yang@intel.com>
>>>> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
>>>> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
>>>> Acked-by: Nirmoy Das <nirmoy.das@intel.com>
>>>
>>> Bspec: 45015, 45040
>>>
>>>> ---
>>>>  drivers/gpu/drm/i915/display/intel_dpt.c |  2 +-
>>>>  drivers/gpu/drm/i915/gt/gen8_ppgtt.c     | 45 ++++++++++++++++++++----
>>>>  drivers/gpu/drm/i915/gt/intel_ggtt.c     | 36 +++++++++++++++++--
>>>>  3 files changed, 72 insertions(+), 11 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/display/intel_dpt.c
>>b/drivers/gpu/drm/i915/display/intel_dpt.c
>>>> index b8027392144d..c5eacfdba1a5 100644
>>>> --- a/drivers/gpu/drm/i915/display/intel_dpt.c
>>>> +++ b/drivers/gpu/drm/i915/display/intel_dpt.c
>>>> @@ -300,7 +300,7 @@ intel_dpt_create(struct intel_framebuffer *fb)
>>>>        vm->vma_ops.bind_vma    = dpt_bind_vma;
>>>>        vm->vma_ops.unbind_vma  = dpt_unbind_vma;
>>>>
>>>> -     vm->pte_encode = gen8_ggtt_pte_encode;
>>>> +     vm->pte_encode = vm->gt->ggtt->vm.pte_encode;
>>>>
>>>>        dpt->obj = dpt_obj;
>>>>        dpt->obj->is_dpt = true;
>>>> diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>>>>  b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>>>> index 4daaa6f55668..11b91e0453c8 100644
>>>> --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>>>> +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>>>> @@ -55,6 +55,34 @@ static u64 gen8_pte_encode(dma_addr_t addr,
>>>>        return pte;
>>>>  }
>>>>
>>>> +static u64 mtl_pte_encode(dma_addr_t addr,
>>>> +                       enum i915_cache_level level,
>>>> +                       u32 flags)
>>>> +{
>>>> +     gen8_pte_t pte = addr | GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
>>>> +
>>>> +     if (unlikely(flags & PTE_READ_ONLY))
>>>> +             pte &= ~GEN8_PAGE_RW;
>>>> +
>>>> +     if (flags & PTE_LM)
>>>> +             pte |= GEN12_PPGTT_PTE_LM | GEN12_PPGTT_PTE_NC;
>>>
>>> GEN12_PPGTT_PTE_NC got defined in the previous patch as BIT(5).  But
>>> according to bspec 45040, bit 5 is ignored in the PTE encoding.  What is
>>> this trying to do?
>>
>> This takes effect only for PTE_LM, doesn't affect MTL.
>> PTE_NC is needed for PVC (use of access counter).
>> I believe this function was writen based on the one for PVC. And this
>> function did get extended to cover all gen12 in a later patch.
>
> Even though MTL doesn't have local memory, PTE_LM is supposed to be
> used on MTL for access to BAR2 stolen memory.

You were right, but I still think this code is fine because this bit is
ignored for MTL anyway and it is needed for other platforms with LMEM.
Otherwise this code would have some sort of platform checking which is
hard to do because we don't have platform info here.
Or we would have to define another PTE encode function for platforms
needing PTE_NC just for this one difference, then manage the function
pointer correctly.

-Fei

> Matt
>
>> -Fei
>>> Matt
>>>
>>>> +
>>>> +     switch (level) {
>>>> +     case I915_CACHE_NONE:
>>>> +             pte |= GEN12_PPGTT_PTE_PAT1;
>>>> +             break;
Matt Roper April 24, 2023, 5:20 p.m. UTC | #5
On Sun, Apr 23, 2023 at 12:37:27AM -0700, Yang, Fei wrote:
> > On Fri, Apr 21, 2023 at 10:27:22AM -0700, Yang, Fei wrote:
> >>> On Wed, Apr 19, 2023 at 04:00:53PM -0700, fei.yang@intel.com wrote:
> >>>> From: Fei Yang <fei.yang@intel.com>
> >>>>
> >>>> PTE encode functions are platform dependent. This patch implements
> >>>> PTE functions for MTL, and ensures the correct PTE encode function
> >>>> is used by calling pte_encode function pointer instead of the
> >>>> hardcoded gen8 version of PTE encode.
> >>>>
> >>>> Signed-off-by: Fei Yang <fei.yang@intel.com>
> >>>> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
> >>>> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
> >>>> Acked-by: Nirmoy Das <nirmoy.das@intel.com>
> >>>
> >>> Bspec: 45015, 45040
> >>>
> >>>> ---
> >>>>  drivers/gpu/drm/i915/display/intel_dpt.c |  2 +-
> >>>>  drivers/gpu/drm/i915/gt/gen8_ppgtt.c     | 45 ++++++++++++++++++++----
> >>>>  drivers/gpu/drm/i915/gt/intel_ggtt.c     | 36 +++++++++++++++++--
> >>>>  3 files changed, 72 insertions(+), 11 deletions(-)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/i915/display/intel_dpt.c
> >>b/drivers/gpu/drm/i915/display/intel_dpt.c
> >>>> index b8027392144d..c5eacfdba1a5 100644
> >>>> --- a/drivers/gpu/drm/i915/display/intel_dpt.c
> >>>> +++ b/drivers/gpu/drm/i915/display/intel_dpt.c
> >>>> @@ -300,7 +300,7 @@ intel_dpt_create(struct intel_framebuffer *fb)
> >>>>        vm->vma_ops.bind_vma    = dpt_bind_vma;
> >>>>        vm->vma_ops.unbind_vma  = dpt_unbind_vma;
> >>>>
> >>>> -     vm->pte_encode = gen8_ggtt_pte_encode;
> >>>> +     vm->pte_encode = vm->gt->ggtt->vm.pte_encode;
> >>>>
> >>>>        dpt->obj = dpt_obj;
> >>>>        dpt->obj->is_dpt = true;
> >>>> diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> >>>>  b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> >>>> index 4daaa6f55668..11b91e0453c8 100644
> >>>> --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> >>>> +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> >>>> @@ -55,6 +55,34 @@ static u64 gen8_pte_encode(dma_addr_t addr,
> >>>>        return pte;
> >>>>  }
> >>>>
> >>>> +static u64 mtl_pte_encode(dma_addr_t addr,
> >>>> +                       enum i915_cache_level level,
> >>>> +                       u32 flags)
> >>>> +{
> >>>> +     gen8_pte_t pte = addr | GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
> >>>> +
> >>>> +     if (unlikely(flags & PTE_READ_ONLY))
> >>>> +             pte &= ~GEN8_PAGE_RW;
> >>>> +
> >>>> +     if (flags & PTE_LM)
> >>>> +             pte |= GEN12_PPGTT_PTE_LM | GEN12_PPGTT_PTE_NC;
> >>>
> >>> GEN12_PPGTT_PTE_NC got defined in the previous patch as BIT(5).  But
> >>> according to bspec 45040, bit 5 is ignored in the PTE encoding.  What is
> >>> this trying to do?
> >>
> >> This takes effect only for PTE_LM, doesn't affect MTL.
> >> PTE_NC is needed for PVC (use of access counter).
> >> I believe this function was writen based on the one for PVC. And this
> >> function did get extended to cover all gen12 in a later patch.
> >
> > Even though MTL doesn't have local memory, PTE_LM is supposed to be
> > used on MTL for access to BAR2 stolen memory.
> 
> You were right, but I still think this code is fine because this bit is
> ignored for MTL anyway and it is needed for other platforms with LMEM.
> Otherwise this code would have some sort of platform checking which is
> hard to do because we don't have platform info here.
> Or we would have to define another PTE encode function for platforms
> needing PTE_NC just for this one difference, then manage the function
> pointer correctly.

MTL is the only platform that uses this function right now:

   +       if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70))
   +               ppgtt->vm.pte_encode = mtl_pte_encode;
   +       else
   +               ppgtt->vm.pte_encode = gen8_pte_encode;

If this is intended for PVC, then you have it in the wrong function to
begin with (and it also shouldn't be in a patch labelled "mtl").  If
you're trying to future-proof for some post-MTL discrete platform, then
such code should be saved until we enable that platform so that it can
be properly reviewed.


Matt

> 
> -Fei
> 
> > Matt
> >
> >> -Fei
> >>> Matt
> >>>
> >>>> +
> >>>> +     switch (level) {
> >>>> +     case I915_CACHE_NONE:
> >>>> +             pte |= GEN12_PPGTT_PTE_PAT1;
> >>>> +             break;
Yang, Fei April 24, 2023, 6:41 p.m. UTC | #6
> On Sun, Apr 23, 2023 at 12:37:27AM -0700, Yang, Fei wrote:
>>> On Fri, Apr 21, 2023 at 10:27:22AM -0700, Yang, Fei wrote:
>>>>> On Wed, Apr 19, 2023 at 04:00:53PM -0700, fei.yang@intel.com wrote:
>>>>>> From: Fei Yang <fei.yang@intel.com>
>>>>>>
>>>>>> PTE encode functions are platform dependent. This patch implements
>>>>>> PTE functions for MTL, and ensures the correct PTE encode function
>>>>>> is used by calling pte_encode function pointer instead of the
>>>>>> hardcoded gen8 version of PTE encode.
>>>>>>
>>>>>> Signed-off-by: Fei Yang <fei.yang@intel.com>
>>>>>> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
>>>>>> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
>>>>>> Acked-by: Nirmoy Das <nirmoy.das@intel.com>
>>>>>
>>>>> Bspec: 45015, 45040
>>>>>
>>>>>> ---
>>>>>>  drivers/gpu/drm/i915/display/intel_dpt.c |  2 +-
>>>>>>  drivers/gpu/drm/i915/gt/gen8_ppgtt.c     | 45 ++++++++++++++++++++----
>>>>>>  drivers/gpu/drm/i915/gt/intel_ggtt.c     | 36 +++++++++++++++++--
>>>>>>  3 files changed, 72 insertions(+), 11 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/gpu/drm/i915/display/intel_dpt.c
>>>>b/drivers/gpu/drm/i915/display/intel_dpt.c
>>>>>> index b8027392144d..c5eacfdba1a5 100644
>>>>>> --- a/drivers/gpu/drm/i915/display/intel_dpt.c
>>>>>> +++ b/drivers/gpu/drm/i915/display/intel_dpt.c
>>>>>> @@ -300,7 +300,7 @@ intel_dpt_create(struct intel_framebuffer *fb)
>>>>>>        vm->vma_ops.bind_vma    = dpt_bind_vma;
>>>>>>        vm->vma_ops.unbind_vma  = dpt_unbind_vma;
>>>>>>
>>>>>> -     vm->pte_encode = gen8_ggtt_pte_encode;
>>>>>> +     vm->pte_encode = vm->gt->ggtt->vm.pte_encode;
>>>>>>
>>>>>>        dpt->obj = dpt_obj;
>>>>>>        dpt->obj->is_dpt = true;
>>>>>> diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>>>>>>  b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>>>>>> index 4daaa6f55668..11b91e0453c8 100644
>>>>>> --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>>>>>> +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>>>>>> @@ -55,6 +55,34 @@ static u64 gen8_pte_encode(dma_addr_t addr,
>>>>>>        return pte;
>>>>>>  }
>>>>>>
>>>>>> +static u64 mtl_pte_encode(dma_addr_t addr,
>>>>>> +                       enum i915_cache_level level,
>>>>>> +                       u32 flags)
>>>>>> +{
>>>>>> +     gen8_pte_t pte = addr | GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
>>>>>> +
>>>>>> +     if (unlikely(flags & PTE_READ_ONLY))
>>>>>> +             pte &= ~GEN8_PAGE_RW;
>>>>>> +
>>>>>> +     if (flags & PTE_LM)
>>>>>> +             pte |= GEN12_PPGTT_PTE_LM | GEN12_PPGTT_PTE_NC;
>>>>>
>>>>> GEN12_PPGTT_PTE_NC got defined in the previous patch as BIT(5).  But
>>>>> according to bspec 45040, bit 5 is ignored in the PTE encoding.  What is
>>>>> this trying to do?
>>>>
>>>> This takes effect only for PTE_LM, doesn't affect MTL.
>>>> PTE_NC is needed for PVC (use of access counter).
>>>> I believe this function was writen based on the one for PVC. And this
>>>> function did get extended to cover all gen12 in a later patch.
>>>
>>> Even though MTL doesn't have local memory, PTE_LM is supposed to be
>>> used on MTL for access to BAR2 stolen memory.
>>
>> You were right, but I still think this code is fine because this bit is
>> ignored for MTL anyway and it is needed for other platforms with LMEM.
>> Otherwise this code would have some sort of platform checking which is
>> hard to do because we don't have platform info here.
>> Or we would have to define another PTE encode function for platforms
>> needing PTE_NC just for this one difference, then manage the function
>> pointer correctly.
>
> MTL is the only platform that uses this function right now:
>
>   +       if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70))
>   +               ppgtt->vm.pte_encode = mtl_pte_encode;
>   +       else
>   +               ppgtt->vm.pte_encode = gen8_pte_encode;
>
> If this is intended for PVC, then you have it in the wrong function to
> begin with (and it also shouldn't be in a patch labelled "mtl").  If
> you're trying to future-proof for some post-MTL discrete platform, then
> such code should be saved until we enable that platform so that it can
> be properly reviewed.

dropped GEN12_PPGTT_PTE_NC bit in v2 of https://patchwork.freedesktop.org/series/116900/

> Matt
>
>>
>> -Fei
>>
>>> Matt
>>>
>>>> -Fei
>>>>> Matt
>>>>>
>>>>>> +
>>>>>> +     switch (level) {
>>>>>> +     case I915_CACHE_NONE:
>>>>>> +             pte |= GEN12_PPGTT_PTE_PAT1;
>>>>>> +             break;
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_dpt.c b/drivers/gpu/drm/i915/display/intel_dpt.c
index b8027392144d..c5eacfdba1a5 100644
--- a/drivers/gpu/drm/i915/display/intel_dpt.c
+++ b/drivers/gpu/drm/i915/display/intel_dpt.c
@@ -300,7 +300,7 @@  intel_dpt_create(struct intel_framebuffer *fb)
 	vm->vma_ops.bind_vma    = dpt_bind_vma;
 	vm->vma_ops.unbind_vma  = dpt_unbind_vma;
 
-	vm->pte_encode = gen8_ggtt_pte_encode;
+	vm->pte_encode = vm->gt->ggtt->vm.pte_encode;
 
 	dpt->obj = dpt_obj;
 	dpt->obj->is_dpt = true;
diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
index 4daaa6f55668..11b91e0453c8 100644
--- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
+++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
@@ -55,6 +55,34 @@  static u64 gen8_pte_encode(dma_addr_t addr,
 	return pte;
 }
 
+static u64 mtl_pte_encode(dma_addr_t addr,
+			  enum i915_cache_level level,
+			  u32 flags)
+{
+	gen8_pte_t pte = addr | GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
+
+	if (unlikely(flags & PTE_READ_ONLY))
+		pte &= ~GEN8_PAGE_RW;
+
+	if (flags & PTE_LM)
+		pte |= GEN12_PPGTT_PTE_LM | GEN12_PPGTT_PTE_NC;
+
+	switch (level) {
+	case I915_CACHE_NONE:
+		pte |= GEN12_PPGTT_PTE_PAT1;
+		break;
+	case I915_CACHE_LLC:
+	case I915_CACHE_L3_LLC:
+		pte |= GEN12_PPGTT_PTE_PAT0 | GEN12_PPGTT_PTE_PAT1;
+		break;
+	case I915_CACHE_WT:
+		pte |= GEN12_PPGTT_PTE_PAT0;
+		break;
+	}
+
+	return pte;
+}
+
 static void gen8_ppgtt_notify_vgt(struct i915_ppgtt *ppgtt, bool create)
 {
 	struct drm_i915_private *i915 = ppgtt->vm.i915;
@@ -427,7 +455,7 @@  gen8_ppgtt_insert_pte(struct i915_ppgtt *ppgtt,
 		      u32 flags)
 {
 	struct i915_page_directory *pd;
-	const gen8_pte_t pte_encode = gen8_pte_encode(0, cache_level, flags);
+	const gen8_pte_t pte_encode = ppgtt->vm.pte_encode(0, cache_level, flags);
 	gen8_pte_t *vaddr;
 
 	pd = i915_pd_entry(pdp, gen8_pd_index(idx, 2));
@@ -580,7 +608,7 @@  static void gen8_ppgtt_insert_huge(struct i915_address_space *vm,
 				   enum i915_cache_level cache_level,
 				   u32 flags)
 {
-	const gen8_pte_t pte_encode = gen8_pte_encode(0, cache_level, flags);
+	const gen8_pte_t pte_encode = vm->pte_encode(0, cache_level, flags);
 	unsigned int rem = sg_dma_len(iter->sg);
 	u64 start = vma_res->start;
 
@@ -743,7 +771,7 @@  static void gen8_ppgtt_insert_entry(struct i915_address_space *vm,
 	GEM_BUG_ON(pt->is_compact);
 
 	vaddr = px_vaddr(pt);
-	vaddr[gen8_pd_index(idx, 0)] = gen8_pte_encode(addr, level, flags);
+	vaddr[gen8_pd_index(idx, 0)] = vm->pte_encode(addr, level, flags);
 	drm_clflush_virt_range(&vaddr[gen8_pd_index(idx, 0)], sizeof(*vaddr));
 }
 
@@ -773,7 +801,7 @@  static void __xehpsdv_ppgtt_insert_entry_lm(struct i915_address_space *vm,
 	}
 
 	vaddr = px_vaddr(pt);
-	vaddr[gen8_pd_index(idx, 0) / 16] = gen8_pte_encode(addr, level, flags);
+	vaddr[gen8_pd_index(idx, 0) / 16] = vm->pte_encode(addr, level, flags);
 }
 
 static void xehpsdv_ppgtt_insert_entry(struct i915_address_space *vm,
@@ -820,8 +848,8 @@  static int gen8_init_scratch(struct i915_address_space *vm)
 		pte_flags |= PTE_LM;
 
 	vm->scratch[0]->encode =
-		gen8_pte_encode(px_dma(vm->scratch[0]),
-				I915_CACHE_NONE, pte_flags);
+		vm->pte_encode(px_dma(vm->scratch[0]),
+			       I915_CACHE_NONE, pte_flags);
 
 	for (i = 1; i <= vm->top; i++) {
 		struct drm_i915_gem_object *obj;
@@ -963,7 +991,10 @@  struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt,
 	 */
 	ppgtt->vm.alloc_scratch_dma = alloc_pt_dma;
 
-	ppgtt->vm.pte_encode = gen8_pte_encode;
+	if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70))
+		ppgtt->vm.pte_encode = mtl_pte_encode;
+	else
+		ppgtt->vm.pte_encode = gen8_pte_encode;
 
 	ppgtt->vm.bind_async_flags = I915_VMA_LOCAL_BIND;
 	ppgtt->vm.insert_entries = gen8_ppgtt_insert;
diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
index 3c7f1ed92f5b..20915edc8bd9 100644
--- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
@@ -220,6 +220,33 @@  static void guc_ggtt_invalidate(struct i915_ggtt *ggtt)
 	}
 }
 
+static u64 mtl_ggtt_pte_encode(dma_addr_t addr,
+			       enum i915_cache_level level,
+			       u32 flags)
+{
+	gen8_pte_t pte = addr | GEN8_PAGE_PRESENT;
+
+	WARN_ON_ONCE(addr & ~GEN12_GGTT_PTE_ADDR_MASK);
+
+	if (flags & PTE_LM)
+		pte |= GEN12_GGTT_PTE_LM;
+
+	switch (level) {
+	case I915_CACHE_NONE:
+		pte |= MTL_GGTT_PTE_PAT1;
+		break;
+	case I915_CACHE_LLC:
+	case I915_CACHE_L3_LLC:
+		pte |= MTL_GGTT_PTE_PAT0 | MTL_GGTT_PTE_PAT1;
+		break;
+	case I915_CACHE_WT:
+		pte |= MTL_GGTT_PTE_PAT0;
+		break;
+	}
+
+	return pte;
+}
+
 u64 gen8_ggtt_pte_encode(dma_addr_t addr,
 			 enum i915_cache_level level,
 			 u32 flags)
@@ -247,7 +274,7 @@  static void gen8_ggtt_insert_page(struct i915_address_space *vm,
 	gen8_pte_t __iomem *pte =
 		(gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
 
-	gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, flags));
+	gen8_set_pte(pte, ggtt->vm.pte_encode(addr, level, flags));
 
 	ggtt->invalidate(ggtt);
 }
@@ -257,8 +284,8 @@  static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
 				     enum i915_cache_level level,
 				     u32 flags)
 {
-	const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, flags);
 	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	const gen8_pte_t pte_encode = ggtt->vm.pte_encode(0, level, flags);
 	gen8_pte_t __iomem *gte;
 	gen8_pte_t __iomem *end;
 	struct sgt_iter iter;
@@ -981,7 +1008,10 @@  static int gen8_gmch_probe(struct i915_ggtt *ggtt)
 	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
 	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
 
-	ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
+	if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70))
+		ggtt->vm.pte_encode = mtl_ggtt_pte_encode;
+	else
+		ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
 
 	return ggtt_probe_common(ggtt, size);
 }