Re: [PATCH v6 1/1] drm/i915: Introduce new macros for i915 PTE

[Lucas De Marchi <lucas.demarchi@xxxxxxxxx>]

On Mon, Dec 06, 2021 at 01:52:45PM -0800, Michael Cheng wrote:
> Certain functions within i915 uses macros that are defined for
> specific architectures by the mmu, such as _PAGE_RW and _PAGE_PRESENT
> (Some architectures don't even have these macros defined, like ARM64).
>
> Instead of re-using bits defined for the CPU, we should use bits
> defined for i915. This patch introduces two new 64 bit macros,
> GEN8_PAGE_PRESENT and GEN8_PAGE_RW, to check for bits 0 and 1 and, to
> replace all occurrences of _PAGE_RW and _PAGE_PRESENT within i915.
>
> v2(Michael Cheng): Use GEN8_ instead of I915_
>
> Signed-off-by: Michael Cheng <michael.cheng@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/gen8_ppgtt.c |  6 +++---
> drivers/gpu/drm/i915/gt/intel_ggtt.c |  2 +-
> drivers/gpu/drm/i915/gt/intel_gtt.h  |  3 +++
> drivers/gpu/drm/i915/gvt/gtt.c       | 12 ++++++------
> 4 files changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> index 9966e9dc5218..95c02096a61b 100644
> --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> @@ -18,7 +18,7 @@
> static u64 gen8_pde_encode(const dma_addr_t addr,
> 			   const enum i915_cache_level level)
> {
> -	u64 pde = addr | _PAGE_PRESENT | _PAGE_RW;
> +	u64 pde = addr | GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
>
> 	if (level != I915_CACHE_NONE)
> 		pde |= PPAT_CACHED_PDE;
> @@ -32,10 +32,10 @@ static u64 gen8_pte_encode(dma_addr_t addr,
> 			   enum i915_cache_level level,
> 			   u32 flags)
> {
> -	gen8_pte_t pte = addr | _PAGE_PRESENT | _PAGE_RW;
> +	gen8_pte_t pte = addr | GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
>
> 	if (unlikely(flags & PTE_READ_ONLY))
> -		pte &= ~_PAGE_RW;
> +		pte &= ~GEN8_PAGE_RW;
>
> 	if (flags & PTE_LM)
> 		pte |= GEN12_PPGTT_PTE_LM;
> diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> index 110d3944f9a2..cbc6d2b1fd9e 100644
> --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> @@ -209,7 +209,7 @@ u64 gen8_ggtt_pte_encode(dma_addr_t addr,
> 			 enum i915_cache_level level,
> 			 u32 flags)
> {
> -	gen8_pte_t pte = addr | _PAGE_PRESENT;
> +	gen8_pte_t pte = addr | GEN8_PAGE_PRESENT;
>
> 	if (flags & PTE_LM)
> 		pte |= GEN12_GGTT_PTE_LM;
> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
> index dfeaef680aac..228fbfe33cb7 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
> @@ -39,6 +39,9 @@
>
> #define NALLOC 3 /* 1 normal, 1 for concurrent threads, 1 for preallocation */
>
> +#define GEN8_PAGE_PRESENT BIT_ULL(0)
> +#define GEN8_PAGE_RW BIT_ULL(1)

ideally this would be together with other GEN8 defines, but this is
minor.

Reviewed-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>

Lucas De Marchi