[PATCH v2 12/14] mm: Remove PFN_MAP, PFN_SPECIAL, PFN_SG_CHAIN and PFN_SG_LAST
From: Alistair Popple <apopple@nvidia.com>
Date: 2025-06-16 11:59:40
Also in:
dri-devel, linux-arm-kernel, linux-cxl, linux-ext4, linux-fsdevel, linux-mm, linux-riscv, linux-xfs, lkml, loongarch, nvdimm
Subsystem:
libnvdimm: non-volatile memory device subsystem, memory management, memory management - core, the rest · Maintainers:
Dan Williams, Vishal Verma, Dave Jiang, Ira Weiny, Andrew Morton, David Hildenbrand, Linus Torvalds
The PFN_MAP flag is no longer used for anything, so remove it.
The PFN_SG_CHAIN and PFN_SG_LAST flags never appear to have been
used so also remove them. The last user of PFN_SPECIAL was removed
by 653d7825c149 ("dcssblk: mark DAX broken, remove FS_DAX_LIMITED
support").
Acked-by: David Hildenbrand <redacted>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Dan Williams <redacted>
Signed-off-by: Alistair Popple <apopple@nvidia.com>
---
Changes since v1:
- Moved this later in series, after PFN_DEV has been removed. This
should solve an issue reported by Marek[1] on RISC-V (and probably
Loongarch and others where pte_devmap() didn't imply pte_special())
[1] - https://lore.kernel.org/linux-mm/957c0d9d-2c37-4d5f-a8b8-8bf90cd0aedb@samsung.com/ (local)
---
include/linux/pfn_t.h | 27 ++-------------------------
mm/memory.c | 2 --
tools/testing/nvdimm/test/iomap.c | 4 ----
3 files changed, 2 insertions(+), 31 deletions(-)
diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
index 2869095..2c00293 100644
--- a/include/linux/pfn_t.h
+++ b/include/linux/pfn_t.h@@ -5,23 +5,11 @@ /* * PFN_FLAGS_MASK - mask of all the possible valid pfn_t flags - * PFN_SG_CHAIN - pfn is a pointer to the next scatterlist entry - * PFN_SG_LAST - pfn references a page and is the last scatterlist entry - * PFN_MAP - pfn has a dynamic page mapping established by a device driver - * PFN_SPECIAL - for CONFIG_FS_DAX_LIMITED builds to allow XIP, but not - * get_user_pages */ #define PFN_FLAGS_MASK (((u64) (~PAGE_MASK)) << (BITS_PER_LONG_LONG - PAGE_SHIFT)) -#define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1)) -#define PFN_SG_LAST (1ULL << (BITS_PER_LONG_LONG - 2)) -#define PFN_MAP (1ULL << (BITS_PER_LONG_LONG - 4)) -#define PFN_SPECIAL (1ULL << (BITS_PER_LONG_LONG - 5)) #define PFN_FLAGS_TRACE \ - { PFN_SPECIAL, "SPECIAL" }, \ - { PFN_SG_CHAIN, "SG_CHAIN" }, \ - { PFN_SG_LAST, "SG_LAST" }, \ - { PFN_MAP, "MAP" } + { } static inline pfn_t __pfn_to_pfn_t(unsigned long pfn, u64 flags) {
@@ -43,7 +31,7 @@ static inline pfn_t phys_to_pfn_t(phys_addr_t addr, u64 flags) static inline bool pfn_t_has_page(pfn_t pfn) { - return (pfn.val & PFN_MAP) == PFN_MAP; + return true; } static inline unsigned long pfn_t_to_pfn(pfn_t pfn)
@@ -94,15 +82,4 @@ static inline pud_t pfn_t_pud(pfn_t pfn, pgprot_t pgprot) #endif #endif -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL -static inline bool pfn_t_special(pfn_t pfn) -{ - return (pfn.val & PFN_SPECIAL) == PFN_SPECIAL; -} -#else -static inline bool pfn_t_special(pfn_t pfn) -{ - return false; -} -#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */ #endif /* _LINUX_PFN_T_H_ */
diff --git a/mm/memory.c b/mm/memory.c
index f69e66d..f1d81ad 100644
--- a/mm/memory.c
+++ b/mm/memory.c@@ -2581,8 +2581,6 @@ static bool vm_mixed_ok(struct vm_area_struct *vma, pfn_t pfn, bool mkwrite) /* these checks mirror the abort conditions in vm_normal_page */ if (vma->vm_flags & VM_MIXEDMAP) return true; - if (pfn_t_special(pfn)) - return true; if (is_zero_pfn(pfn_t_to_pfn(pfn))) return true; return false;
diff --git a/tools/testing/nvdimm/test/iomap.c b/tools/testing/nvdimm/test/iomap.c
index e431372..ddceb04 100644
--- a/tools/testing/nvdimm/test/iomap.c
+++ b/tools/testing/nvdimm/test/iomap.c@@ -137,10 +137,6 @@ EXPORT_SYMBOL_GPL(__wrap_devm_memremap_pages); pfn_t __wrap_phys_to_pfn_t(phys_addr_t addr, unsigned long flags) { - struct nfit_test_resource *nfit_res = get_nfit_res(addr); - - if (nfit_res) - flags &= ~PFN_MAP; return phys_to_pfn_t(addr, flags); } EXPORT_SYMBOL(__wrap_phys_to_pfn_t);
--
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