RE: [PATCH 11/12] mm: Remove callers of pfn_t functionality
From: Michael Kelley <hidden>
Date: 2025-06-02 04:44:09
Also in:
dri-devel, linux-arm-kernel, linux-cxl, linux-ext4, linux-fsdevel, linux-mm, linux-riscv, linux-xfs, lkml, loongarch, nvdimm
From: Alistair Popple <apopple@nvidia.com> Sent: Wednesday, May 28, 2025 11:32 PM
All PFN_* pfn_t flags have been removed. Therefore there is no longer a need for the pfn_t type and all uses can be replaced with normal pfns. Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> --- arch/x86/mm/pat/memtype.c | 6 +- drivers/dax/device.c | 23 +++---- drivers/dax/hmem/hmem.c | 1 +- drivers/dax/kmem.c | 1 +- drivers/dax/pmem.c | 1 +- drivers/dax/super.c | 3 +- drivers/gpu/drm/exynos/exynos_drm_gem.c | 1 +- drivers/gpu/drm/gma500/fbdev.c | 3 +- drivers/gpu/drm/i915/gem/i915_gem_mman.c | 1 +- drivers/gpu/drm/msm/msm_gem.c | 1 +- drivers/gpu/drm/omapdrm/omap_gem.c | 6 +-- drivers/gpu/drm/v3d/v3d_bo.c | 1 +- drivers/hwtracing/intel_th/msu.c | 3 +- drivers/md/dm-linear.c | 2 +- drivers/md/dm-log-writes.c | 2 +- drivers/md/dm-stripe.c | 2 +- drivers/md/dm-target.c | 2 +- drivers/md/dm-writecache.c | 11 +-- drivers/md/dm.c | 2 +- drivers/nvdimm/pmem.c | 8 +-- drivers/nvdimm/pmem.h | 4 +- drivers/s390/block/dcssblk.c | 9 +-- drivers/vfio/pci/vfio_pci_core.c | 5 +- fs/cramfs/inode.c | 5 +- fs/dax.c | 50 +++++++-------- fs/ext4/file.c | 2 +- fs/fuse/dax.c | 3 +- fs/fuse/virtio_fs.c | 5 +- fs/xfs/xfs_file.c | 2 +- include/linux/dax.h | 9 +-- include/linux/device-mapper.h | 2 +- include/linux/huge_mm.h | 6 +- include/linux/mm.h | 4 +- include/linux/pfn.h | 9 +--- include/linux/pfn_t.h | 85 +------------------------- include/linux/pgtable.h | 4 +- include/trace/events/fs_dax.h | 12 +--- mm/debug_vm_pgtable.c | 1 +- mm/huge_memory.c | 27 +++----- mm/memory.c | 31 ++++----- mm/memremap.c | 1 +- mm/migrate.c | 1 +- tools/testing/nvdimm/pmem-dax.c | 6 +- tools/testing/nvdimm/test/iomap.c | 7 +-- tools/testing/nvdimm/test/nfit_test.h | 1 +- 45 files changed, 121 insertions(+), 250 deletions(-) delete mode 100644 include/linux/pfn_t.h
[snip]
quoted hunk ↗ jump to hunk
diff --git a/include/linux/mm.h b/include/linux/mm.h index c5345ee..12d9665 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h@@ -3644,9 +3644,9 @@ vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr, vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn, pgprot_t pgprot); vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr, - pfn_t pfn); + unsigned long pfn); vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma, - unsigned long addr, pfn_t pfn); + unsigned long addr, unsigned long pfn); int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len); static inline vm_fault_t vmf_insert_page(struct vm_area_struct *vma,
[snip]
quoted hunk ↗ jump to hunk
diff --git a/mm/memory.c b/mm/memory.c index 6b03771..4eaf444 100644 --- a/mm/memory.c +++ b/mm/memory.c@@ -2635,7 +2634,7 @@ EXPORT_SYMBOL(vmf_insert_mixed); * the same entry was actually inserted. */ vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma, - unsigned long addr, pfn_t pfn) + unsigned long addr, unsigned long pfn) { return __vm_insert_mixed(vma, addr, pfn, true); }
vmf_insert_mixed_mkwrite() is not used anywhere in the kernel. The commit message for cd1e0dac3a3e suggests it was originally used by DAX code, so presumably it could just go away. On the flip side, I have a patch set in flight (see Patch 3 of [1]) that uses it to do mkwrite on a special PTE, and my usage requires passing PFN_SPECIAL in order to pass the tests in vm_mixed_ok(). But this may be dubious usage, and should not be a blocker to your elimination of pfn_t. I'll either add vmf_insert_special_mkwrite() or figure out an equivalent. Anyone with suggestions in that direction would be appreciated as I'm not an mm expert. Michael [1] https://lore.kernel.org/linux-hyperv/20250523161522.409504-1-mhklinux@outlook.com/ (local)