Re: [Intel-gfx] [PATCH 19/20] drm/i915/lmem: don't treat small BAR as an error

Thomas Hellström
2022-02-03T09:48:40Z

On 1/26/22 16:21, Matthew Auld wrote:
> Just pass along the probed io_size. The backend should be able to
> utilize the entire range here, even if some of it is non-mappable.
Changes here LGTM.
>
> It does leave open with what to do with stolen local-memory.

Are objects in stolen local required to be mappable?

/Thomas

>
> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> ---
> drivers/gpu/drm/i915/gt/intel_region_lmem.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_region_lmem.c b/drivers/gpu/drm/i915/gt/intel_region_lmem.c
> index 2c7ec7ff79fd..b788fc2b3df8 100644
> --- a/drivers/gpu/drm/i915/gt/intel_region_lmem.c
> +++ b/drivers/gpu/drm/i915/gt/intel_region_lmem.c
> @@ -200,6 +200,7 @@ static struct intel_memory_region *setup_lmem(struct intel_gt *gt)
> struct intel_memory_region *mem;
> resource_size_t min_page_size;
> resource_size_t io_start;
> + resource_size_t io_size;
> resource_size_t lmem_size;
> int err;
>
> @@ -210,7 +211,8 @@ static struct intel_memory_region *setup_lmem(struct intel_gt *gt)
> lmem_size = intel_uncore_read64(uncore, GEN12_GSMBASE);
>
> io_start = pci_resource_start(pdev, 2);
> - if (GEM_WARN_ON(lmem_size > pci_resource_len(pdev, 2)))
> + io_size = min(pci_resource_len(pdev, 2), lmem_size);
> + if (!io_size)
> return ERR_PTR(-ENODEV);
>
> min_page_size = HAS_64K_PAGES(i915) ? I915_GTT_PAGE_SIZE_64K :
> @@ -220,7 +222,7 @@ static struct intel_memory_region *setup_lmem(struct intel_gt *gt)
> lmem_size,
> min_page_size,
> io_start,
> - lmem_size,
> + io_size,
> INTEL_MEMORY_LOCAL,
> 0,
> &intel_region_lmem_ops);