Commit d438d273 authored by Alistair Popple's avatar Alistair Popple Committed by Andrew Morton
Browse files

mm: remove devmap related functions and page table bits 

Now that DAX and all other reference counts to ZONE_DEVICE pages are
managed normally there is no need for the special devmap PTE/PMD/PUD page
table bits.  So drop all references to these, freeing up a software
defined page table bit on architectures supporting it.

Link: https://lkml.kernel.org/r/6389398c32cc9daa3dfcaa9f79c7972525d310ce.1750323463.git-series.apopple@nvidia.com


Signed-off-by: default avatarAlistair Popple <apopple@nvidia.com>
Acked-by: Will Deacon <will@kernel.org> # arm64
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Suggested-by: default avatarChunyan Zhang <zhang.lyra@gmail.com>
Reviewed-by: default avatarBjörn Töpel <bjorn@rivosinc.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Björn Töpel <bjorn@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Inki Dae <m.szyprowski@samsung.com>
Cc: John Groves <john@groves.net>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 28dc88c3

Documentation/mm/arch_pgtable_helpers.rst

+0 −6
Original line number Diff line number Diff line
@@ -30,8 +30,6 @@ PTE Page Table Helpers 
+---------------------------+--------------------------------------------------+

| pte_protnone              | Tests a PROT_NONE PTE                            |

+---------------------------+--------------------------------------------------+

| pte_devmap                | Tests a ZONE_DEVICE mapped PTE                   |

+---------------------------+--------------------------------------------------+

| pte_soft_dirty            | Tests a soft dirty PTE                           |

+---------------------------+--------------------------------------------------+

| pte_swp_soft_dirty        | Tests a soft dirty swapped PTE                   |
@@ -104,8 +102,6 @@ PMD Page Table Helpers 
+---------------------------+--------------------------------------------------+

| pmd_protnone              | Tests a PROT_NONE PMD                            |

+---------------------------+--------------------------------------------------+

| pmd_devmap                | Tests a ZONE_DEVICE mapped PMD                   |

+---------------------------+--------------------------------------------------+

| pmd_soft_dirty            | Tests a soft dirty PMD                           |

+---------------------------+--------------------------------------------------+

| pmd_swp_soft_dirty        | Tests a soft dirty swapped PMD                   |
@@ -177,8 +173,6 @@ PUD Page Table Helpers 
+---------------------------+--------------------------------------------------+

| pud_write                 | Tests a writable PUD                             |

+---------------------------+--------------------------------------------------+

| pud_devmap                | Tests a ZONE_DEVICE mapped PUD                   |

+---------------------------+--------------------------------------------------+

| pud_mkyoung               | Creates a young PUD                              |

+---------------------------+--------------------------------------------------+

| pud_mkold                 | Creates an old PUD                               |

arch/arm64/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -44,7 +44,6 @@ config ARM64 
	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT

	select ARCH_HAS_PREEMPT_LAZY

	select ARCH_HAS_PTDUMP

	select ARCH_HAS_PTE_DEVMAP

	select ARCH_HAS_PTE_SPECIAL

	select ARCH_HAS_HW_PTE_YOUNG

	select ARCH_HAS_SETUP_DMA_OPS

arch/arm64/include/asm/pgtable-prot.h

+0 −1
Original line number Diff line number Diff line
@@ -17,7 +17,6 @@ 
#define PTE_SWP_EXCLUSIVE	(_AT(pteval_t, 1) << 2)	 /* only for swp ptes */

#define PTE_DIRTY		(_AT(pteval_t, 1) << 55)

#define PTE_SPECIAL		(_AT(pteval_t, 1) << 56)

#define PTE_DEVMAP		(_AT(pteval_t, 1) << 57)



/*

 * PTE_PRESENT_INVALID=1 & PTE_VALID=0 indicates that the pte's fields should be

arch/arm64/include/asm/pgtable.h

+0 −24
Original line number Diff line number Diff line
@@ -190,7 +190,6 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t phys) 
#define pte_user(pte)		(!!(pte_val(pte) & PTE_USER))

#define pte_user_exec(pte)	(!(pte_val(pte) & PTE_UXN))

#define pte_cont(pte)		(!!(pte_val(pte) & PTE_CONT))

#define pte_devmap(pte)		(!!(pte_val(pte) & PTE_DEVMAP))

#define pte_tagged(pte)		((pte_val(pte) & PTE_ATTRINDX_MASK) == \

				 PTE_ATTRINDX(MT_NORMAL_TAGGED))
@@ -372,11 +371,6 @@ static inline pmd_t pmd_mkcont(pmd_t pmd) 
	return __pmd(pmd_val(pmd) | PMD_SECT_CONT);

}



static inline pte_t pte_mkdevmap(pte_t pte)

{

	return set_pte_bit(pte, __pgprot(PTE_DEVMAP | PTE_SPECIAL));

}



#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP

static inline int pte_uffd_wp(pte_t pte)

{
@@ -653,14 +647,6 @@ static inline pmd_t pmd_mkhuge(pmd_t pmd) 
	return __pmd((pmd_val(pmd) & ~mask) | val);

}



#ifdef CONFIG_TRANSPARENT_HUGEPAGE

#define pmd_devmap(pmd)		pte_devmap(pmd_pte(pmd))

#endif

static inline pmd_t pmd_mkdevmap(pmd_t pmd)

{

	return pte_pmd(set_pte_bit(pmd_pte(pmd), __pgprot(PTE_DEVMAP)));

}



#ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP

#define pmd_special(pte)	(!!((pmd_val(pte) & PTE_SPECIAL)))

static inline pmd_t pmd_mkspecial(pmd_t pmd)
@@ -1302,16 +1288,6 @@ static inline int pmdp_set_access_flags(struct vm_area_struct *vma, 
	return __ptep_set_access_flags(vma, address, (pte_t *)pmdp,

							pmd_pte(entry), dirty);

}



static inline int pud_devmap(pud_t pud)

{

	return 0;

}



static inline int pgd_devmap(pgd_t pgd)

{

	return 0;

}

#endif



#ifdef CONFIG_PAGE_TABLE_CHECK

arch/loongarch/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -25,7 +25,6 @@ config LOONGARCH 
	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS

	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE

	select ARCH_HAS_PREEMPT_LAZY

	select ARCH_HAS_PTE_DEVMAP

	select ARCH_HAS_PTE_SPECIAL

	select ARCH_HAS_SET_MEMORY

	select ARCH_HAS_SET_DIRECT_MAP