Re: [PATCH 2/4] drm/i915/xehpsdv: set min page-size to 64K

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

On 12/8/21 15:34, Matthew Auld wrote:
> On Wed, 8 Dec 2021 at 14:16, Ramalingam C <ramalingam.c@intel.com> wrote:
>> From: Matthew Auld <matthew.auld@intel.com>
>>
>> LMEM should be allocated at 64K granularity, since 4K page support will
>> eventually be dropped for LMEM when using the PPGTT.
> s/will eventually be dropped/has been dropped/ as per Thomas' suggestion.

Or perhaps something along the lines of

Conditionally allocate LMEM with 64K granularity, since 4K page support 
for LMEM will be dropped on some platforms when using the PPGTT.

/Thomas



>
>> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
>> Signed-off-by: Stuart Summers <stuart.summers@intel.com>
>> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
>> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
>> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
>> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
>> Reviewed-by: Thomas Hellstrom <thomas.hellstrom@linux.intel.com>
>> ---
>>   drivers/gpu/drm/i915/gem/i915_gem_stolen.c  | 6 +++++-
>>   drivers/gpu/drm/i915/gt/intel_region_lmem.c | 5 ++++-
>>   2 files changed, 9 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
>> index bce03d74a0b4..ba90ab47d838 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
>> @@ -780,6 +780,7 @@ i915_gem_stolen_lmem_setup(struct drm_i915_private *i915, u16 type,
>>          struct intel_uncore *uncore = &i915->uncore;
>>          struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>>          struct intel_memory_region *mem;
>> +       resource_size_t min_page_size;
>>          resource_size_t io_start;
>>          resource_size_t lmem_size;
>>          u64 lmem_base;
>> @@ -791,8 +792,11 @@ i915_gem_stolen_lmem_setup(struct drm_i915_private *i915, u16 type,
>>          lmem_size = pci_resource_len(pdev, 2) - lmem_base;
>>          io_start = pci_resource_start(pdev, 2) + lmem_base;
>>
>> +       min_page_size = HAS_64K_PAGES(i915) ? I915_GTT_PAGE_SIZE_64K :
>> +                                               I915_GTT_PAGE_SIZE_4K;
>> +
>>          mem = intel_memory_region_create(i915, lmem_base, lmem_size,
>> -                                        I915_GTT_PAGE_SIZE_4K, io_start,
>> +                                        min_page_size, io_start,
>>                                           type, instance,
>>                                           &i915_region_stolen_lmem_ops);
>>          if (IS_ERR(mem))
>> diff --git a/drivers/gpu/drm/i915/gt/intel_region_lmem.c b/drivers/gpu/drm/i915/gt/intel_region_lmem.c
>> index 9ea49e0a27c0..fde2dcb59809 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_region_lmem.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_region_lmem.c
>> @@ -197,6 +197,7 @@ static struct intel_memory_region *setup_lmem(struct intel_gt *gt)
>>          struct intel_uncore *uncore = gt->uncore;
>>          struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>>          struct intel_memory_region *mem;
>> +       resource_size_t min_page_size;
>>          resource_size_t io_start;
>>          resource_size_t lmem_size;
>>          int err;
>> @@ -211,10 +212,12 @@ static struct intel_memory_region *setup_lmem(struct intel_gt *gt)
>>          if (GEM_WARN_ON(lmem_size > pci_resource_len(pdev, 2)))
>>                  return ERR_PTR(-ENODEV);
>>
>> +       min_page_size = HAS_64K_PAGES(i915) ? I915_GTT_PAGE_SIZE_64K :
>> +                                               I915_GTT_PAGE_SIZE_4K;
>>          mem = intel_memory_region_create(i915,
>>                                           0,
>>                                           lmem_size,
>> -                                        I915_GTT_PAGE_SIZE_4K,
>> +                                        min_page_size,
>>                                           io_start,
>>                                           INTEL_MEMORY_LOCAL,
>>                                           0,
>> --
>> 2.20.1
>>