Re: [PATCH v2 02/11] drm/amdkfd: Use migrate pfns internally
From: Felix Kuehling <felix.kuehling@amd.com>
Date: 2026-01-08 22:00:44
Also in:
dri-devel, intel-xe, linux-mm, lkml
On 2026-01-07 04:18, Jordan Niethe wrote:
quoted hunk ↗ jump to hunk
A future change will remove device private pages from the physical address space. This will mean that device private pages no longer have a pfn. A MIGRATE_PFN flag will be introduced that distinguishes between mpfns that contain a pfn vs an offset into device private memory. Replace usages of pfns and page_to_pfn() to mpfns and migrate_pfn_to_page() to prepare for handling this distinction. This will assist in continuing to use the same code paths for both MEMORY_DEVICE_PRIVATE and MEMORY_DEVICE_COHERENT devices. Signed-off-by: Jordan Niethe <redacted> --- v2: - New to series --- drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 15 +++++++-------- drivers/gpu/drm/amd/amdkfd/kfd_migrate.h | 2 +- 2 files changed, 8 insertions(+), 9 deletions(-)diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c index ca552c34ece2..c493b19268cc 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c@@ -204,17 +204,17 @@ svm_migrate_copy_done(struct amdgpu_device *adev, struct dma_fence *mfence) } unsigned long -svm_migrate_addr_to_pfn(struct amdgpu_device *adev, unsigned long addr) +svm_migrate_addr_to_mpfn(struct amdgpu_device *adev, unsigned long addr) { - return (addr + adev->kfd.pgmap.range.start) >> PAGE_SHIFT; + return migrate_pfn((addr + adev->kfd.pgmap.range.start) >> PAGE_SHIFT); } static void -svm_migrate_get_vram_page(struct svm_range *prange, unsigned long pfn) +svm_migrate_get_vram_page(struct svm_range *prange, unsigned long mpfn) { struct page *page; - page = pfn_to_page(pfn); + page = migrate_pfn_to_page(mpfn); svm_range_bo_ref(prange->svm_bo); page->zone_device_data = prange->svm_bo; zone_device_page_init(page, 0);@@ -225,7 +225,7 @@ svm_migrate_put_vram_page(struct amdgpu_device *adev, unsigned long addr) { struct page *page; - page = pfn_to_page(svm_migrate_addr_to_pfn(adev, addr)); + page = migrate_pfn_to_page(svm_migrate_addr_to_mpfn(adev, addr)); unlock_page(page); put_page(page); }@@ -235,7 +235,7 @@ svm_migrate_addr(struct amdgpu_device *adev, struct page *page) { unsigned long addr; - addr = page_to_pfn(page) << PAGE_SHIFT; + addr = (migrate_pfn_from_page(page) >> MIGRATE_PFN_SHIFT) << PAGE_SHIFT; return (addr - adev->kfd.pgmap.range.start);
I guess we rely on the fact that for DEVICE_PRIVATE memory, adev->kfd.pgmap.range.start will be 0 after your patch 11. So we don't need a special condition here to handle DEVICE_PRIVATE differently. In general, I like the way you handle mpfns as it keeps all the special casing out of the drivers. Regards, Felix
quoted hunk ↗ jump to hunk
}@@ -301,9 +301,8 @@ svm_migrate_copy_to_vram(struct kfd_node *node, struct svm_range *prange, if (migrate->src[i] & MIGRATE_PFN_MIGRATE) { dst[i] = cursor.start + (j << PAGE_SHIFT); - migrate->dst[i] = svm_migrate_addr_to_pfn(adev, dst[i]); + migrate->dst[i] = svm_migrate_addr_to_mpfn(adev, dst[i]); svm_migrate_get_vram_page(prange, migrate->dst[i]); - migrate->dst[i] = migrate_pfn(migrate->dst[i]); mpages++; } spage = migrate_pfn_to_page(migrate->src[i]);diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.h b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.h index 2b7fd442d29c..a80b72abe1e0 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.h +++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.h@@ -48,7 +48,7 @@ int svm_migrate_vram_to_ram(struct svm_range *prange, struct mm_struct *mm, uint32_t trigger, struct page *fault_page); unsigned long -svm_migrate_addr_to_pfn(struct amdgpu_device *adev, unsigned long addr); +svm_migrate_addr_to_mpfn(struct amdgpu_device *adev, unsigned long addr); #endif /* IS_ENABLED(CONFIG_HSA_AMD_SVM) */