[PATCH 01/12] mm: Remove PFN_MAP, PFN_SG_CHAIN and PFN_SG_LAST

Alistair Popple
2025-05-29T06:32:28Z

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.

Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
include/linux/pfn_t.h | 31 +++----------------------------
mm/memory.c | 2 --
tools/testing/nvdimm/test/iomap.c | 4 ----
3 files changed, 3 insertions(+), 34 deletions(-)

diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
index 2d91482..46afa12 100644
--- a/include/linux/pfn_t.h
+++ b/include/linux/pfn_t.h
@@ -5,26 +5,13 @@

/*
* 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_DEV - pfn is not covered by system memmap by default
- * 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_DEV (1ULL << (BITS_PER_LONG_LONG - 3))
-#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_DEV, "DEV" }, \
- { PFN_MAP, "MAP" }
+ { PFN_DEV, "DEV" }

static inline pfn_t __pfn_to_pfn_t(unsigned long pfn, u64 flags)
{
@@ -46,7 +33,7 @@ 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 || (pfn.val & PFN_DEV) == 0;
+ return (pfn.val & PFN_DEV) == 0;
}

static inline unsigned long pfn_t_to_pfn(pfn_t pfn)
@@ -100,7 +87,7 @@ static inline pud_t pfn_t_pud(pfn_t pfn, pgprot_t pgprot)
#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
static inline bool pfn_t_devmap(pfn_t pfn)
{
- const u64 flags = PFN_DEV|PFN_MAP;
+ const u64 flags = PFN_DEV;

return (pfn.val & flags) == flags;
}
@@ -116,16 +103,4 @@ pmd_t pmd_mkdevmap(pmd_t pmd);
pud_t pud_mkdevmap(pud_t pud);
#endif
#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
-
-#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 4919941..cc85f81 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2569,8 +2569,6 @@ static bool vm_mixed_ok(struct vm_area_struct *vma, pfn_t pfn, bool mkwrite)
return true;
if (pfn_t_devmap(pfn))
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);
--
git-series 0.9.1