* Mike Rapoport <[email protected]> [260211 05:32]: > From: "Mike Rapoport (Microsoft)" <[email protected]> > > Reduce 22 declarations of empty_zero_page to 3 and 23 declarations of > ZERO_PAGE() to 4. > > Every architecture defines empty_zero_page that way or another, but for the > most of them it is always a page aligned page in BSS and most definitions > of ZERO_PAGE do virt_to_page(empty_zero_page). > > Move Linus vetted x86 definition of empty_zero_page and ZERO_PAGE() to the > core MM and drop these definitions in architectures that do not implement > colored zero page (MIPS and s390). > > ZERO_PAGE() remains a macro because turning it to a wrapper for a static > inline causes severe pain in header dependencies. > > For the most part the change is mechanical, with these being noteworthy: > > * alpha: aliased empty_zero_page with ZERO_PGE that was also used for boot > parameters. Switching to a generic empty_zero_page removes the aliasing > and keeps ZERO_PGE for boot parameters only > * arm64: uses __pa_symbol() in ZERO_PAGE() so that definition of > ZERO_PAGE() is kept intact. > * m68k/parisc/um: allocated empty_zero_page from memblock, > although they do not support zero page coloring and having it in BSS > will work fine. > * sparc64 can have empty_zero_page in BSS rather allocate it, but it > can't use virt_to_page() for BSS. Keep it's definition of ZERO_PAGE() > but instead of allocating it, make mem_map_zero point to > empty_zero_page. > * sh: used empty_zero_page for boot parameters at the very early boot. > Rename the parameters page to boot_params_page and let sh use the generic > empty_zero_page. > * hexagon: had an amusing comment about empty_zero_page > > /* A handy thing to have if one has the RAM. Declared in head.S */ > > that unfortunately had to go :) > > Acked-by: Helge Deller <[email protected]> # parisc > Tested-by: Helge Deller <[email protected]> # parisc > Reviewed-by: Christophe Leroy (CS GROUP) <[email protected]> > Acked-by: Dave Hansen <[email protected]> > Acked-by: Catalin Marinas <[email protected]> > Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Acked-by: Liam R. Howlett <[email protected]> > --- > arch/alpha/include/asm/pgtable.h | 6 ------ > arch/arc/include/asm/pgtable.h | 3 --- > arch/arc/mm/init.c | 2 -- > arch/arm/include/asm/pgtable.h | 9 --------- > arch/arm/mm/mmu.c | 7 ------- > arch/arm/mm/nommu.c | 7 ------- > arch/arm64/include/asm/pgtable.h | 1 - > arch/arm64/mm/mmu.c | 7 ------- > arch/csky/include/asm/pgtable.h | 3 --- > arch/csky/mm/init.c | 3 --- > arch/hexagon/include/asm/pgtable.h | 6 ------ > arch/hexagon/kernel/head.S | 5 ----- > arch/hexagon/kernel/hexagon_ksyms.c | 1 - > arch/loongarch/include/asm/pgtable.h | 9 --------- > arch/loongarch/mm/init.c | 3 --- > arch/m68k/include/asm/pgtable_mm.h | 9 --------- > arch/m68k/include/asm/pgtable_no.h | 7 ------- > arch/m68k/mm/init.c | 9 --------- > arch/m68k/mm/mcfmmu.c | 2 -- > arch/m68k/mm/motorola.c | 6 ------ > arch/m68k/mm/sun3mmu.c | 2 -- > arch/microblaze/include/asm/pgtable.h | 10 ---------- > arch/microblaze/kernel/head.S | 4 ---- > arch/microblaze/kernel/microblaze_ksyms.c | 2 -- > arch/nios2/include/asm/pgtable.h | 7 ------- > arch/nios2/kernel/head.S | 10 ---------- > arch/nios2/kernel/nios2_ksyms.c | 1 - > arch/openrisc/include/asm/pgtable.h | 4 ---- > arch/openrisc/kernel/head.S | 3 --- > arch/openrisc/kernel/or32_ksyms.c | 1 - > arch/openrisc/mm/init.c | 3 --- > arch/parisc/include/asm/pgtable.h | 11 ----------- > arch/parisc/mm/init.c | 6 ------ > arch/powerpc/include/asm/pgtable.h | 6 ------ > arch/powerpc/mm/mem.c | 3 --- > arch/riscv/include/asm/pgtable.h | 7 ------- > arch/riscv/mm/init.c | 4 ---- > arch/sh/include/asm/pgtable.h | 8 -------- > arch/sh/include/asm/setup.h | 3 ++- > arch/sh/kernel/head_32.S | 4 ++-- > arch/sh/kernel/sh_ksyms_32.c | 1 - > arch/sh/mm/init.c | 1 - > arch/sparc/include/asm/pgtable_32.h | 8 -------- > arch/sparc/include/asm/setup.h | 2 -- > arch/sparc/kernel/head_32.S | 7 ------- > arch/sparc/mm/init_32.c | 4 ---- > arch/sparc/mm/init_64.c | 11 ++++------- > arch/um/include/asm/pgtable.h | 9 --------- > arch/um/include/shared/kern_util.h | 1 - > arch/um/kernel/mem.c | 16 ---------------- > arch/um/kernel/um_arch.c | 1 - > arch/x86/include/asm/pgtable.h | 8 -------- > arch/x86/kernel/head_32.S | 4 ---- > arch/x86/kernel/head_64.S | 7 ------- > arch/xtensa/include/asm/pgtable.h | 4 ---- > arch/xtensa/kernel/head.S | 3 --- > arch/xtensa/kernel/xtensa_ksyms.c | 2 -- > include/linux/pgtable.h | 10 ++++++++++ > mm/mm_init.c | 5 +++++ > 59 files changed, 23 insertions(+), 285 deletions(-) > > diff --git a/arch/alpha/include/asm/pgtable.h > b/arch/alpha/include/asm/pgtable.h > index 90e7a9539102..12a3c5f8ece8 100644 > --- a/arch/alpha/include/asm/pgtable.h > +++ b/arch/alpha/include/asm/pgtable.h > @@ -125,12 +125,6 @@ struct vm_area_struct; > */ > #define pgprot_noncached(prot) (prot) > > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > -#define ZERO_PAGE(vaddr) (virt_to_page(ZERO_PGE)) > - > /* > * On certain platforms whose physical address space can overlap KSEG, > * namely EV6 and above, we must re-twiddle the physaddr to restore the > diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h > index bd580e2b62d7..0fdaea81b5fa 100644 > --- a/arch/arc/include/asm/pgtable.h > +++ b/arch/arc/include/asm/pgtable.h > @@ -21,9 +21,6 @@ > > #ifndef __ASSEMBLER__ > > -extern char empty_zero_page[PAGE_SIZE]; > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > extern pgd_t swapper_pg_dir[] __aligned(PAGE_SIZE); > > /* to cope with aliasing VIPT cache */ > diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c > index a5e92f46e5d1..d6b5c27a0098 100644 > --- a/arch/arc/mm/init.c > +++ b/arch/arc/mm/init.c > @@ -19,8 +19,6 @@ > #include <asm/arcregs.h> > > pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE); > -char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE); > -EXPORT_SYMBOL(empty_zero_page); > > static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE; > static unsigned long low_mem_sz; > diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h > index 6fa9acd6a7f5..982795cf4563 100644 > --- a/arch/arm/include/asm/pgtable.h > +++ b/arch/arm/include/asm/pgtable.h > @@ -10,15 +10,6 @@ > #include <linux/const.h> > #include <asm/proc-fns.h> > > -#ifndef __ASSEMBLY__ > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > -extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > -#endif > - > #include <asm-generic/pgtable-nopud.h> > > #ifndef CONFIG_MMU > diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c > index 518def8314e7..23b87b5ef7f1 100644 > --- a/arch/arm/mm/mmu.c > +++ b/arch/arm/mm/mmu.c > @@ -41,13 +41,6 @@ > > extern unsigned long __atags_pointer; > > -/* > - * empty_zero_page is a special page that is used for > - * zero-initialized data and COW. > - */ > -unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] > __page_aligned_bss; > -EXPORT_SYMBOL(empty_zero_page); > - > /* > * The pmd table for the upper-most set of pages. > */ > diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c > index 7e42d8accec6..040ea43cce32 100644 > --- a/arch/arm/mm/nommu.c > +++ b/arch/arm/mm/nommu.c > @@ -27,13 +27,6 @@ > > unsigned long vectors_base; > > -/* > - * empty_zero_page is a special page that is used for > - * zero-initialized data and COW. > - */ > -unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] > __page_aligned_bss; > -EXPORT_SYMBOL(empty_zero_page); > - > #ifdef CONFIG_ARM_MPU > struct mpu_rgn_info mpu_rgn_info; > #endif > diff --git a/arch/arm64/include/asm/pgtable.h > b/arch/arm64/include/asm/pgtable.h > index d94445b4f3df..63da07398a30 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -110,7 +110,6 @@ static inline void arch_leave_lazy_mmu_mode(void) > * ZERO_PAGE is a global shared page that is always zero: used > * for zero-mapped memory areas etc.. > */ > -extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > #define ZERO_PAGE(vaddr) phys_to_page(__pa_symbol(empty_zero_page)) > > #define pte_ERROR(e) \ > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index a6a00accf4f9..0f6a171faf1f 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -64,13 +64,6 @@ static bool rodata_is_rw __ro_after_init = true; > */ > long __section(".mmuoff.data.write") __early_cpu_boot_status; > > -/* > - * Empty_zero_page is a special page that is used for zero-initialized data > - * and COW. > - */ > -unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] > __page_aligned_bss; > -EXPORT_SYMBOL(empty_zero_page); > - > static DEFINE_SPINLOCK(swapper_pgdir_lock); > static DEFINE_MUTEX(fixmap_lock); > > diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h > index d606afbabce1..bafcd5823531 100644 > --- a/arch/csky/include/asm/pgtable.h > +++ b/arch/csky/include/asm/pgtable.h > @@ -76,9 +76,6 @@ > #define MAX_SWAPFILES_CHECK() \ > BUILD_BUG_ON(MAX_SWAPFILES_SHIFT != 5) > > -extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > extern void load_pgd(unsigned long pg_dir); > extern pte_t invalid_pte_table[PTRS_PER_PTE]; > > diff --git a/arch/csky/mm/init.c b/arch/csky/mm/init.c > index 573da66b2543..fa16015ea1c0 100644 > --- a/arch/csky/mm/init.c > +++ b/arch/csky/mm/init.c > @@ -38,9 +38,6 @@ pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss; > pte_t kernel_pte_tables[PTRS_KERN_TABLE] __page_aligned_bss; > > EXPORT_SYMBOL(invalid_pte_table); > -unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] > - __page_aligned_bss; > -EXPORT_SYMBOL(empty_zero_page); > > void free_initmem(void) > { > diff --git a/arch/hexagon/include/asm/pgtable.h > b/arch/hexagon/include/asm/pgtable.h > index fbf24d1d1ca6..27b269e2870d 100644 > --- a/arch/hexagon/include/asm/pgtable.h > +++ b/arch/hexagon/include/asm/pgtable.h > @@ -14,9 +14,6 @@ > #include <asm/page.h> > #include <asm-generic/pgtable-nopmd.h> > > -/* A handy thing to have if one has the RAM. Declared in head.S */ > -extern unsigned long empty_zero_page; > - > /* > * The PTE model described here is that of the Hexagon Virtual Machine, > * which autonomously walks 2-level page tables. At a lower level, we > @@ -348,9 +345,6 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd) > return (unsigned long)__va(pmd_val(pmd) & PAGE_MASK); > } > > -/* ZERO_PAGE - returns the globally shared zero page */ > -#define ZERO_PAGE(vaddr) (virt_to_page(&empty_zero_page)) > - > /* > * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that > * are !pte_none() && !pte_present(). > diff --git a/arch/hexagon/kernel/head.S b/arch/hexagon/kernel/head.S > index 0b016308cc79..908ffece9132 100644 > --- a/arch/hexagon/kernel/head.S > +++ b/arch/hexagon/kernel/head.S > @@ -216,8 +216,3 @@ __head_s_vaddr_target: > .p2align PAGE_SHIFT > ENTRY(external_cmdline_buffer) > .fill _PAGE_SIZE,1,0 > - > -.data > -.p2align PAGE_SHIFT > -ENTRY(empty_zero_page) > - .fill _PAGE_SIZE,1,0 > diff --git a/arch/hexagon/kernel/hexagon_ksyms.c > b/arch/hexagon/kernel/hexagon_ksyms.c > index 36a80e31d187..81bc6f81e200 100644 > --- a/arch/hexagon/kernel/hexagon_ksyms.c > +++ b/arch/hexagon/kernel/hexagon_ksyms.c > @@ -17,7 +17,6 @@ EXPORT_SYMBOL(raw_copy_to_user); > EXPORT_SYMBOL(__vmgetie); > EXPORT_SYMBOL(__vmsetie); > EXPORT_SYMBOL(__vmyield); > -EXPORT_SYMBOL(empty_zero_page); > EXPORT_SYMBOL(memcpy); > EXPORT_SYMBOL(memset); > > diff --git a/arch/loongarch/include/asm/pgtable.h > b/arch/loongarch/include/asm/pgtable.h > index c33b3bcb733e..a244de27a03e 100644 > --- a/arch/loongarch/include/asm/pgtable.h > +++ b/arch/loongarch/include/asm/pgtable.h > @@ -74,15 +74,6 @@ > struct mm_struct; > struct vm_area_struct; > > -/* > - * ZERO_PAGE is a global shared page that is always zero; used > - * for zero-mapped memory areas etc.. > - */ > - > -extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > - > -#define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page) > - > #ifdef CONFIG_32BIT > > #define VMALLOC_START (vm_map_base + PCI_IOSIZE + (2 * PAGE_SIZE)) > diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c > index c331bf69d2ec..00f3822b6e47 100644 > --- a/arch/loongarch/mm/init.c > +++ b/arch/loongarch/mm/init.c > @@ -36,9 +36,6 @@ > #include <asm/pgalloc.h> > #include <asm/tlb.h> > > -unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] > __page_aligned_bss; > -EXPORT_SYMBOL(empty_zero_page); > - > void copy_user_highpage(struct page *to, struct page *from, > unsigned long vaddr, struct vm_area_struct *vma) > { > diff --git a/arch/m68k/include/asm/pgtable_mm.h > b/arch/m68k/include/asm/pgtable_mm.h > index bba64a9c49ac..7501ff030c63 100644 > --- a/arch/m68k/include/asm/pgtable_mm.h > +++ b/arch/m68k/include/asm/pgtable_mm.h > @@ -110,15 +110,6 @@ extern unsigned long m68k_vmalloc_end; > #define VMALLOC_END KMAP_START > #endif > > -/* zero page used for uninitialized stuff */ > -extern void *empty_zero_page; > - > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > extern void kernel_set_cachemode(void *addr, unsigned long size, int cmode); > > /* > diff --git a/arch/m68k/include/asm/pgtable_no.h > b/arch/m68k/include/asm/pgtable_no.h > index 1a86c15b9008..11751807a3f3 100644 > --- a/arch/m68k/include/asm/pgtable_no.h > +++ b/arch/m68k/include/asm/pgtable_no.h > @@ -30,13 +30,6 @@ > > #define swapper_pg_dir ((pgd_t *) 0) > > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > -extern void *empty_zero_page; > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > /* > * All 32bit addresses are effectively valid for vmalloc... > * Sort of meaningless for non-VM targets. > diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c > index 53b71f786c27..3b88c0dd1616 100644 > --- a/arch/m68k/mm/init.c > +++ b/arch/m68k/mm/init.c > @@ -33,13 +33,6 @@ > #include <asm/sections.h> > #include <asm/tlb.h> > > -/* > - * ZERO_PAGE is a special page that is used for zero-initialized > - * data and COW. > - */ > -void *empty_zero_page; > -EXPORT_SYMBOL(empty_zero_page); > - > void __init arch_zone_limits_init(unsigned long *max_zone_pfns) > { > max_zone_pfns[ZONE_DMA] = PFN_DOWN(memblock_end_of_DRAM()); > @@ -71,8 +64,6 @@ void __init paging_init(void) > unsigned long end_mem = memory_end & PAGE_MASK; > > high_memory = (void *) end_mem; > - > - empty_zero_page = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE); > } > > #endif /* CONFIG_MMU */ > diff --git a/arch/m68k/mm/mcfmmu.c b/arch/m68k/mm/mcfmmu.c > index 3418fd864237..4924f2ff8ef8 100644 > --- a/arch/m68k/mm/mcfmmu.c > +++ b/arch/m68k/mm/mcfmmu.c > @@ -41,8 +41,6 @@ void __init paging_init(void) > unsigned long next_pgtable; > int i; > > - empty_zero_page = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE); > - > pg_dir = swapper_pg_dir; > memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir)); > > diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c > index 127a3fa69f4c..b30aa69a73a6 100644 > --- a/arch/m68k/mm/motorola.c > +++ b/arch/m68k/mm/motorola.c > @@ -498,12 +498,6 @@ void __init paging_init(void) > > early_memtest(min_addr, max_addr); > > - /* > - * initialize the bad page table and bad page to point > - * to a couple of allocated pages > - */ > - empty_zero_page = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE); > - > /* > * Set up SFC/DFC registers > */ > diff --git a/arch/m68k/mm/sun3mmu.c b/arch/m68k/mm/sun3mmu.c > index c801677f7df8..f139cc15753a 100644 > --- a/arch/m68k/mm/sun3mmu.c > +++ b/arch/m68k/mm/sun3mmu.c > @@ -43,8 +43,6 @@ void __init paging_init(void) > unsigned long bootmem_end; > unsigned long size; > > - empty_zero_page = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE); > - > address = PAGE_OFFSET; > pg_dir = swapper_pg_dir; > memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir)); > diff --git a/arch/microblaze/include/asm/pgtable.h > b/arch/microblaze/include/asm/pgtable.h > index 4eb76de6be4a..ea72291de553 100644 > --- a/arch/microblaze/include/asm/pgtable.h > +++ b/arch/microblaze/include/asm/pgtable.h > @@ -207,16 +207,6 @@ extern pte_t *va_to_pte(unsigned long address); > * Also, write permissions imply read permissions. > */ > > -#ifndef __ASSEMBLER__ > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > -extern unsigned long empty_zero_page[1024]; > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > -#endif /* __ASSEMBLER__ */ > - > #define pte_none(pte) ((pte_val(pte) & ~_PTE_NONE_MASK) == 0) > #define pte_present(pte) (pte_val(pte) & _PAGE_PRESENT) > #define pte_clear(mm, addr, ptep) \ > diff --git a/arch/microblaze/kernel/head.S b/arch/microblaze/kernel/head.S > index ec2fcb545e64..808019c3b7ac 100644 > --- a/arch/microblaze/kernel/head.S > +++ b/arch/microblaze/kernel/head.S > @@ -39,10 +39,6 @@ > #include <asm/processor.h> > > .section .data > -.global empty_zero_page > -.align 12 > -empty_zero_page: > - .space PAGE_SIZE > .global swapper_pg_dir > swapper_pg_dir: > .space PAGE_SIZE > diff --git a/arch/microblaze/kernel/microblaze_ksyms.c > b/arch/microblaze/kernel/microblaze_ksyms.c > index a8553f54152b..ad7596d7ba07 100644 > --- a/arch/microblaze/kernel/microblaze_ksyms.c > +++ b/arch/microblaze/kernel/microblaze_ksyms.c > @@ -33,8 +33,6 @@ EXPORT_SYMBOL(memcpy); > EXPORT_SYMBOL(memmove); > #endif > > -EXPORT_SYMBOL(empty_zero_page); > - > EXPORT_SYMBOL(mbc); > > extern void __divsi3(void); > diff --git a/arch/nios2/include/asm/pgtable.h > b/arch/nios2/include/asm/pgtable.h > index 844dce55569f..d389aa9ca57c 100644 > --- a/arch/nios2/include/asm/pgtable.h > +++ b/arch/nios2/include/asm/pgtable.h > @@ -65,13 +65,6 @@ struct mm_struct; > #define PGDIR_SIZE (1UL << PGDIR_SHIFT) > #define PGDIR_MASK (~(PGDIR_SIZE-1)) > > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > -extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; > extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)]; > > diff --git a/arch/nios2/kernel/head.S b/arch/nios2/kernel/head.S > index 372ce4a33018..613212e1a63a 100644 > --- a/arch/nios2/kernel/head.S > +++ b/arch/nios2/kernel/head.S > @@ -23,16 +23,6 @@ > #include <asm/asm-offsets.h> > #include <asm/asm-macros.h> > > -/* > - * ZERO_PAGE is a special page that is used for zero-initialized > - * data and COW. > - */ > -.data > -.global empty_zero_page > -.align 12 > -empty_zero_page: > - .space PAGE_SIZE > - > /* > * This global variable is used as an extension to the nios' > * STATUS register to emulate a user/supervisor mode. > diff --git a/arch/nios2/kernel/nios2_ksyms.c b/arch/nios2/kernel/nios2_ksyms.c > index 54f7b23df1bf..c40aa39e8658 100644 > --- a/arch/nios2/kernel/nios2_ksyms.c > +++ b/arch/nios2/kernel/nios2_ksyms.c > @@ -20,7 +20,6 @@ EXPORT_SYMBOL(memmove); > > /* memory management */ > > -EXPORT_SYMBOL(empty_zero_page); > EXPORT_SYMBOL(flush_icache_range); > > /* > diff --git a/arch/openrisc/include/asm/pgtable.h > b/arch/openrisc/include/asm/pgtable.h > index b218050e2f6d..6b89996d0b62 100644 > --- a/arch/openrisc/include/asm/pgtable.h > +++ b/arch/openrisc/include/asm/pgtable.h > @@ -179,10 +179,6 @@ extern void paging_init(void); > __pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \ > | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC | _PAGE_CI) > > -/* zero page used for uninitialized stuff */ > -extern unsigned long empty_zero_page[2048]; > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > #define pte_none(x) (!pte_val(x)) > #define pte_present(x) (pte_val(x) & _PAGE_PRESENT) > #define pte_clear(mm, addr, xp) do { pte_val(*(xp)) = 0; } while (0) > diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S > index bd760066f1cd..45890393947d 100644 > --- a/arch/openrisc/kernel/head.S > +++ b/arch/openrisc/kernel/head.S > @@ -1563,9 +1563,6 @@ _string_nl: > */ > .section .data,"aw" > .align 8192 > - .global empty_zero_page > -empty_zero_page: > - .space 8192 > > .global swapper_pg_dir > swapper_pg_dir: > diff --git a/arch/openrisc/kernel/or32_ksyms.c > b/arch/openrisc/kernel/or32_ksyms.c > index 212e5f85004c..84a937a64e2a 100644 > --- a/arch/openrisc/kernel/or32_ksyms.c > +++ b/arch/openrisc/kernel/or32_ksyms.c > @@ -40,7 +40,6 @@ DECLARE_EXPORT(__ashldi3); > DECLARE_EXPORT(__lshrdi3); > DECLARE_EXPORT(__ucmpdi2); > > -EXPORT_SYMBOL(empty_zero_page); > EXPORT_SYMBOL(__copy_tofrom_user); > EXPORT_SYMBOL(__clear_user); > EXPORT_SYMBOL(memset); > diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c > index 78fb0734cdbc..89d8c6df8855 100644 > --- a/arch/openrisc/mm/init.c > +++ b/arch/openrisc/mm/init.c > @@ -188,9 +188,6 @@ void __init mem_init(void) > { > BUG_ON(!mem_map); > > - /* clear the zero-page */ > - memset((void *)empty_zero_page, 0, PAGE_SIZE); > - > printk("mem_init_done ...........................................\n"); > mem_init_done = 1; > return; > diff --git a/arch/parisc/include/asm/pgtable.h > b/arch/parisc/include/asm/pgtable.h > index 2c139a4dbf4b..cbdc01a26ea0 100644 > --- a/arch/parisc/include/asm/pgtable.h > +++ b/arch/parisc/include/asm/pgtable.h > @@ -262,17 +262,6 @@ extern pgd_t swapper_pg_dir[]; /* declared in > init_task.c */ > > extern pte_t pg0[]; > > -/* zero page used for uninitialized stuff */ > - > -extern unsigned long *empty_zero_page; > - > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > - > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > #define pte_none(x) (pte_val(x) == 0) > #define pte_present(x) (pte_val(x) & _PAGE_PRESENT) > #define pte_user(x) (pte_val(x) & _PAGE_USER) > diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c > index 6a39e031e5ff..be3380c9bcda 100644 > --- a/arch/parisc/mm/init.c > +++ b/arch/parisc/mm/init.c > @@ -604,9 +604,6 @@ void __init mem_init(void) > #endif > } > > -unsigned long *empty_zero_page __ro_after_init; > -EXPORT_SYMBOL(empty_zero_page); > - > /* > * pagetable_init() sets up the page tables > * > @@ -639,9 +636,6 @@ static void __init pagetable_init(void) > initrd_end - initrd_start, PAGE_KERNEL, 0); > } > #endif > - > - empty_zero_page = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE); > - > } > > static void __init gateway_init(void) > diff --git a/arch/powerpc/include/asm/pgtable.h > b/arch/powerpc/include/asm/pgtable.h > index dcd3a88caaf6..b27d94c06d0e 100644 > --- a/arch/powerpc/include/asm/pgtable.h > +++ b/arch/powerpc/include/asm/pgtable.h > @@ -76,12 +76,6 @@ static inline const void *pmd_page_vaddr(pmd_t pmd) > } > #define pmd_page_vaddr pmd_page_vaddr > #endif > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > -extern unsigned long empty_zero_page[]; > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > > extern pgd_t swapper_pg_dir[]; > > diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c > index 3789a51bdaae..85508392a6b6 100644 > --- a/arch/powerpc/mm/mem.c > +++ b/arch/powerpc/mm/mem.c > @@ -34,9 +34,6 @@ > > unsigned long long memory_limit __initdata; > > -unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] > __page_aligned_bss; > -EXPORT_SYMBOL(empty_zero_page); > - > pgprot_t __phys_mem_access_prot(unsigned long pfn, unsigned long size, > pgprot_t vma_prot) > { > diff --git a/arch/riscv/include/asm/pgtable.h > b/arch/riscv/include/asm/pgtable.h > index 9ecbf0366719..a6b496f4944f 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -1258,13 +1258,6 @@ extern u64 satp_mode; > void paging_init(void); > void misc_mem_init(void); > > -/* > - * ZERO_PAGE is a global shared page that is always zero, > - * used for zero-mapped memory areas, etc. > - */ > -extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > /* > * Use set_p*_safe(), and elide TLB flushing, when confident that *no* > * TLB flush will be required as a result of the "set". For example, use > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 848efeb9e163..95ac79c62067 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -69,10 +69,6 @@ unsigned long vmemmap_start_pfn __ro_after_init; > EXPORT_SYMBOL(vmemmap_start_pfn); > #endif > > -unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] > - __page_aligned_bss; > -EXPORT_SYMBOL(empty_zero_page); > - > extern char _start[]; > void *_dtb_early_va __initdata; > uintptr_t _dtb_early_pa __initdata; > diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h > index 10fa8f2bb8d1..d5ce0950a323 100644 > --- a/arch/sh/include/asm/pgtable.h > +++ b/arch/sh/include/asm/pgtable.h > @@ -20,14 +20,6 @@ > #ifndef __ASSEMBLER__ > #include <asm/addrspace.h> > #include <asm/fixmap.h> > - > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > -extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > #endif /* !__ASSEMBLER__ */ > > /* > diff --git a/arch/sh/include/asm/setup.h b/arch/sh/include/asm/setup.h > index 84bb23a771f3..63c9efc06348 100644 > --- a/arch/sh/include/asm/setup.h > +++ b/arch/sh/include/asm/setup.h > @@ -7,7 +7,8 @@ > /* > * This is set up by the setup-routine at boot-time > */ > -#define PARAM ((unsigned char *)empty_zero_page) > +extern unsigned char *boot_params_page; > +#define PARAM boot_params_page > > #define MOUNT_ROOT_RDONLY (*(unsigned long *) (PARAM+0x000)) > #define RAMDISK_FLAGS (*(unsigned long *) (PARAM+0x004)) > diff --git a/arch/sh/kernel/head_32.S b/arch/sh/kernel/head_32.S > index b603b7968b38..0b91bb85d40a 100644 > --- a/arch/sh/kernel/head_32.S > +++ b/arch/sh/kernel/head_32.S > @@ -26,7 +26,7 @@ > #endif > > .section .empty_zero_page, "aw" > -ENTRY(empty_zero_page) > +ENTRY(boot_params_page) > .long 1 /* MOUNT_ROOT_RDONLY */ > .long 0 /* RAMDISK_FLAGS */ > .long 0x0200 /* ORIG_ROOT_DEV */ > @@ -39,7 +39,7 @@ ENTRY(empty_zero_page) > .long 0x53453f00 + 29 /* "SE?" = 29 bit */ > #endif > 1: > - .skip PAGE_SIZE - empty_zero_page - 1b > + .skip PAGE_SIZE - boot_params_page - 1b > > __HEAD > > diff --git a/arch/sh/kernel/sh_ksyms_32.c b/arch/sh/kernel/sh_ksyms_32.c > index 5858936cb431..041191002e2e 100644 > --- a/arch/sh/kernel/sh_ksyms_32.c > +++ b/arch/sh/kernel/sh_ksyms_32.c > @@ -20,7 +20,6 @@ EXPORT_SYMBOL(csum_partial); > EXPORT_SYMBOL(csum_partial_copy_generic); > EXPORT_SYMBOL(copy_page); > EXPORT_SYMBOL(__clear_user); > -EXPORT_SYMBOL(empty_zero_page); > #ifdef CONFIG_FLATMEM > /* need in pfn_valid macro */ > EXPORT_SYMBOL(min_low_pfn); > diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c > index 464a3a63e2fa..4e40d5e96be9 100644 > --- a/arch/sh/mm/init.c > +++ b/arch/sh/mm/init.c > @@ -332,7 +332,6 @@ void __init mem_init(void) > cpu_cache_init(); > > /* clear the zero-page */ > - memset(empty_zero_page, 0, PAGE_SIZE); > __flush_wback_region(empty_zero_page, PAGE_SIZE); > > vsyscall_init(); > diff --git a/arch/sparc/include/asm/pgtable_32.h > b/arch/sparc/include/asm/pgtable_32.h > index a9f802d1dd64..f89b1250661d 100644 > --- a/arch/sparc/include/asm/pgtable_32.h > +++ b/arch/sparc/include/asm/pgtable_32.h > @@ -71,14 +71,6 @@ extern unsigned long ptr_in_current_pgd; > extern unsigned long phys_base; > extern unsigned long pfn_base; > > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > -extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > - > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > /* > * In general all page table modifications should use the V8 atomic > * swap instruction. This insures the mmu and the cpu are in sync > diff --git a/arch/sparc/include/asm/setup.h b/arch/sparc/include/asm/setup.h > index 72205684e51e..21bed5514028 100644 > --- a/arch/sparc/include/asm/setup.h > +++ b/arch/sparc/include/asm/setup.h > @@ -17,8 +17,6 @@ extern char reboot_command[]; > */ > extern unsigned char boot_cpu_id; > > -extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > - > extern int serial_console; > static inline int con_is_present(void) > { > diff --git a/arch/sparc/kernel/head_32.S b/arch/sparc/kernel/head_32.S > index 38345460d542..8c320fa25a67 100644 > --- a/arch/sparc/kernel/head_32.S > +++ b/arch/sparc/kernel/head_32.S > @@ -57,13 +57,6 @@ sun4e_notsup: > > .align PAGE_SIZE > > -/* This was the only reasonable way I could think of to properly align > - * these page-table data structures. > - */ > - .globl empty_zero_page > -empty_zero_page: .skip PAGE_SIZE > -EXPORT_SYMBOL(empty_zero_page) > - > .global root_flags > .global ram_flags > .global root_dev > diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c > index fdc93dd12c3e..e0e66f91ceeb 100644 > --- a/arch/sparc/mm/init_32.c > +++ b/arch/sparc/mm/init_32.c > @@ -246,10 +246,6 @@ void __init arch_mm_preinit(void) > prom_halt(); > } > > - > - /* Saves us work later. */ > - memset((void *)empty_zero_page, 0, PAGE_SIZE); > - > i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5); > i += 1; > sparc_valid_addr_bitmap = (unsigned long *) > diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c > index 4f7bdb18774b..0cc8de2fea90 100644 > --- a/arch/sparc/mm/init_64.c > +++ b/arch/sparc/mm/init_64.c > @@ -2498,6 +2498,9 @@ static void __init register_page_bootmem_info(void) > } > void __init mem_init(void) > { > + phys_addr_t zero_page_pa = kern_base + > + ((unsigned long)&empty_zero_page[0] - KERNBASE); > + > /* > * Must be done after boot memory is put on freelist, because here we > * might set fields in deferred struct pages that have not yet been > @@ -2510,13 +2513,7 @@ void __init mem_init(void) > * Set up the zero page, mark it reserved, so that page count > * is not manipulated when freeing the page from user ptes. > */ > - mem_map_zero = alloc_pages(GFP_KERNEL|__GFP_ZERO, 0); > - if (mem_map_zero == NULL) { > - prom_printf("paging_init: Cannot alloc zero page.\n"); > - prom_halt(); > - } > - mark_page_reserved(mem_map_zero); > - > + mem_map_zero = pfn_to_page(PHYS_PFN(zero_page_pa)); > > if (tlb_type == cheetah || tlb_type == cheetah_plus) > cheetah_ecache_flush_init(); > diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h > index 3b42b0f45bf6..19e0608fb649 100644 > --- a/arch/um/include/asm/pgtable.h > +++ b/arch/um/include/asm/pgtable.h > @@ -34,9 +34,6 @@ > > extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; > > -/* zero page used for uninitialized stuff */ > -extern unsigned long *empty_zero_page; > - > /* Just any arbitrary offset to the start of the vmalloc VM area: the > * current 8MB value just means that there will be a 8MB "hole" after the > * physical memory until the kernel virtual memory starts. That means that > @@ -74,12 +71,6 @@ extern unsigned long *empty_zero_page; > * get.. > */ > > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > -#define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page) > - > #define pte_clear(mm, addr, xp) pte_set_val(*(xp), (phys_t) 0, > __pgprot(_PAGE_NEEDSYNC)) > > #define pmd_none(x) (!((unsigned long)pmd_val(x) & ~_PAGE_NEEDSYNC)) > diff --git a/arch/um/include/shared/kern_util.h > b/arch/um/include/shared/kern_util.h > index 38321188c04c..9812efd14ec0 100644 > --- a/arch/um/include/shared/kern_util.h > +++ b/arch/um/include/shared/kern_util.h > @@ -38,7 +38,6 @@ extern void timer_handler(int sig, struct siginfo > *unused_si, struct uml_pt_regs > extern void uml_pm_wake(void); > > extern int start_uml(void); > -extern void paging_init(void); > > extern void uml_cleanup(void); > extern void do_uml_exitcalls(void); > diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c > index 89c8c8b94a79..1eef0e42ef5d 100644 > --- a/arch/um/kernel/mem.c > +++ b/arch/um/kernel/mem.c > @@ -44,10 +44,6 @@ __section(".kasan_init") __used > = kasan_init; > #endif > > -/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */ > -unsigned long *empty_zero_page = NULL; > -EXPORT_SYMBOL(empty_zero_page); > - > /* > * Initialized during boot, and readonly for initializing page tables > * afterwards > @@ -65,9 +61,6 @@ void __init arch_mm_preinit(void) > /* Safe to call after jump_label_init(). Enables KASAN. */ > kasan_init_generic(); > > - /* clear the zero-page */ > - memset(empty_zero_page, 0, PAGE_SIZE); > - > /* Map in the area just after the brk now that kmalloc is about > * to be turned on. > */ > @@ -89,15 +82,6 @@ void __init arch_zone_limits_init(unsigned long > *max_zone_pfns) > max_zone_pfns[ZONE_NORMAL] = high_physmem >> PAGE_SHIFT; > } > > -void __init paging_init(void) > -{ > - empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE, > - PAGE_SIZE); > - if (!empty_zero_page) > - panic("%s: Failed to allocate %lu bytes align=%lx\n", > - __func__, PAGE_SIZE, PAGE_SIZE); > -} > - > /* > * This can't do anything because nothing in the kernel image can be freed > * since it's not in kernel physical memory. > diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c > index e2b24e1ecfa6..2141f5f1f5a2 100644 > --- a/arch/um/kernel/um_arch.c > +++ b/arch/um/kernel/um_arch.c > @@ -413,7 +413,6 @@ void __init setup_arch(char **cmdline_p) > uml_dtb_init(); > read_initrd(); > > - paging_init(); > strscpy(boot_command_line, command_line, COMMAND_LINE_SIZE); > *cmdline_p = command_line; > setup_hostinfo(host_info, sizeof host_info); > diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h > index 1662c5a8f445..54289f4587a4 100644 > --- a/arch/x86/include/asm/pgtable.h > +++ b/arch/x86/include/asm/pgtable.h > @@ -47,14 +47,6 @@ void ptdump_walk_user_pgd_level_checkwx(void); > #define debug_checkwx_user() do { } while (0) > #endif > > -/* > - * ZERO_PAGE is a global shared page that is always zero: used > - * for zero-mapped memory areas etc.. > - */ > -extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] > - __visible; > -#define ZERO_PAGE(vaddr) ((void)(vaddr),virt_to_page(empty_zero_page)) > - > extern spinlock_t pgd_lock; > extern struct list_head pgd_list; > > diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S > index 80ef5d386b03..5171cb746444 100644 > --- a/arch/x86/kernel/head_32.S > +++ b/arch/x86/kernel/head_32.S > @@ -441,10 +441,6 @@ initial_pg_fixmap: > swapper_pg_dir: > .fill 1024,4,0 > .fill PTI_USER_PGD_FILL,4,0 > -.globl empty_zero_page > -empty_zero_page: > - .fill 4096,1,0 > -EXPORT_SYMBOL(empty_zero_page) > > /* > * This starts the data section. > diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S > index 21816b48537c..cbf7647a25d8 100644 > --- a/arch/x86/kernel/head_64.S > +++ b/arch/x86/kernel/head_64.S > @@ -712,10 +712,3 @@ SYM_PIC_ALIAS(phys_base); > EXPORT_SYMBOL(phys_base) > > #include "../xen/xen-head.S" > - > - __PAGE_ALIGNED_BSS > -SYM_DATA_START_PAGE_ALIGNED(empty_zero_page) > - .skip PAGE_SIZE > -SYM_DATA_END(empty_zero_page) > -EXPORT_SYMBOL(empty_zero_page) > - > diff --git a/arch/xtensa/include/asm/pgtable.h > b/arch/xtensa/include/asm/pgtable.h > index 50a136213b2b..61f07d981a94 100644 > --- a/arch/xtensa/include/asm/pgtable.h > +++ b/arch/xtensa/include/asm/pgtable.h > @@ -209,10 +209,6 @@ > #define pgd_ERROR(e) \ > printk("%s:%d: bad pgd entry %08lx.\n", __FILE__, __LINE__, pgd_val(e)) > > -extern unsigned long empty_zero_page[1024]; > - > -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > - > #ifdef CONFIG_MMU > extern pgd_t swapper_pg_dir[PAGE_SIZE/sizeof(pgd_t)]; > extern void paging_init(void); > diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S > index 8484294bc623..4b0c5c5e685a 100644 > --- a/arch/xtensa/kernel/head.S > +++ b/arch/xtensa/kernel/head.S > @@ -381,6 +381,3 @@ ENTRY(swapper_pg_dir) > .fill PAGE_SIZE, 1, 0 > END(swapper_pg_dir) > #endif > -ENTRY(empty_zero_page) > - .fill PAGE_SIZE, 1, 0 > -END(empty_zero_page) > diff --git a/arch/xtensa/kernel/xtensa_ksyms.c > b/arch/xtensa/kernel/xtensa_ksyms.c > index 62d81e76e18e..ced335b4df5f 100644 > --- a/arch/xtensa/kernel/xtensa_ksyms.c > +++ b/arch/xtensa/kernel/xtensa_ksyms.c > @@ -15,8 +15,6 @@ > #include <linux/module.h> > #include <asm/pgtable.h> > > -EXPORT_SYMBOL(empty_zero_page); > - > unsigned int __sync_fetch_and_and_4(volatile void *p, unsigned int v) > { > BUG(); > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index 9bacf4df9769..3d48eea57cd2 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -1890,6 +1890,9 @@ static inline void pfnmap_setup_cachemode_pfn(unsigned > long pfn, pgprot_t *prot) > * for different ranges in the virtual address space. > * > * zero_page_pfn identifies the first (or the only) pfn for these pages. > + * > + * For architectures that don't __HAVE_COLOR_ZERO_PAGE the zero page lives in > + * empty_zero_page in BSS. > */ > #ifdef __HAVE_COLOR_ZERO_PAGE > static inline int is_zero_pfn(unsigned long pfn) > @@ -1916,6 +1919,13 @@ static inline unsigned long zero_pfn(unsigned long > addr) > > return zero_page_pfn; > } > + > +extern uint8_t empty_zero_page[PAGE_SIZE]; > + > +#ifndef ZERO_PAGE > +#define ZERO_PAGE(vaddr) ((void)(vaddr),virt_to_page(empty_zero_page)) > +#endif > + > #endif /* __HAVE_COLOR_ZERO_PAGE */ > > #ifdef CONFIG_MMU > diff --git a/mm/mm_init.c b/mm/mm_init.c > index a0ca236eb4f5..1eac634ece1a 100644 > --- a/mm/mm_init.c > +++ b/mm/mm_init.c > @@ -56,6 +56,11 @@ EXPORT_SYMBOL(high_memory); > unsigned long zero_page_pfn __ro_after_init; > EXPORT_SYMBOL(zero_page_pfn); > > +#ifndef __HAVE_COLOR_ZERO_PAGE > +uint8_t empty_zero_page[PAGE_SIZE] __page_aligned_bss; > +EXPORT_SYMBOL(empty_zero_page); > +#endif > + > #ifdef CONFIG_DEBUG_MEMORY_INIT > int __meminitdata mminit_loglevel; > > -- > 2.51.0 > _______________________________________________ linux-snps-arc mailing list [email protected] http://lists.infradead.org/mailman/listinfo/linux-snps-arc
