From: Mike Rapoport <rppt@xxxxxxxxxxxxx> Subject: arch, mm: make kernel_page_present() always available For architectures that enable ARCH_HAS_SET_MEMORY having the ability to verify that a page is mapped in the kernel direct map can be useful regardless of hibernation. Add RISC-V implementation of kernel_page_present(), update its forward declarations and stubs to be a part of set_memory API and remove ugly ifdefery in inlcude/linux/mm.h around current declarations of kernel_page_present(). Link: https://lkml.kernel.org/r/20201109192128.960-5-rppt@xxxxxxxxxx Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: "Edgecombe, Rick P" <rick.p.edgecombe@xxxxxxxxx> Cc: Heiko Carstens <hca@xxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Len Brown <len.brown@xxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx> Cc: Pavel Machek <pavel@xxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/arm64/include/asm/cacheflush.h | 1 arch/arm64/mm/pageattr.c | 4 --- arch/riscv/include/asm/set_memory.h | 1 arch/riscv/mm/pageattr.c | 29 ++++++++++++++++++++++++++ arch/x86/include/asm/set_memory.h | 1 arch/x86/mm/pat/set_memory.c | 4 --- include/linux/mm.h | 7 ------ include/linux/set_memory.h | 5 ++++ 8 files changed, 39 insertions(+), 13 deletions(-) --- a/arch/arm64/include/asm/cacheflush.h~arch-mm-make-kernel_page_present-always-available +++ a/arch/arm64/include/asm/cacheflush.h @@ -140,6 +140,7 @@ int set_memory_valid(unsigned long addr, int set_direct_map_invalid_noflush(struct page *page); int set_direct_map_default_noflush(struct page *page); +bool kernel_page_present(struct page *page); #include <asm-generic/cacheflush.h> --- a/arch/arm64/mm/pageattr.c~arch-mm-make-kernel_page_present-always-available +++ a/arch/arm64/mm/pageattr.c @@ -186,8 +186,8 @@ void __kernel_map_pages(struct page *pag set_memory_valid((unsigned long)page_address(page), numpages, enable); } +#endif /* CONFIG_DEBUG_PAGEALLOC */ -#ifdef CONFIG_HIBERNATION /* * This function is used to determine if a linear map page has been marked as * not-valid. Walk the page table and check the PTE_VALID bit. This is based @@ -234,5 +234,3 @@ bool kernel_page_present(struct page *pa ptep = pte_offset_kernel(pmdp, addr); return pte_valid(READ_ONCE(*ptep)); } -#endif /* CONFIG_HIBERNATION */ -#endif /* CONFIG_DEBUG_PAGEALLOC */ --- a/arch/riscv/include/asm/set_memory.h~arch-mm-make-kernel_page_present-always-available +++ a/arch/riscv/include/asm/set_memory.h @@ -24,6 +24,7 @@ static inline int set_memory_nx(unsigned int set_direct_map_invalid_noflush(struct page *page); int set_direct_map_default_noflush(struct page *page); +bool kernel_page_present(struct page *page); #endif /* __ASSEMBLY__ */ --- a/arch/riscv/mm/pageattr.c~arch-mm-make-kernel_page_present-always-available +++ a/arch/riscv/mm/pageattr.c @@ -198,3 +198,32 @@ void __kernel_map_pages(struct page *pag __pgprot(0), __pgprot(_PAGE_PRESENT)); } #endif + +bool kernel_page_present(struct page *page) +{ + unsigned long addr = (unsigned long)page_address(page); + pgd_t *pgd; + pud_t *pud; + p4d_t *p4d; + pmd_t *pmd; + pte_t *pte; + + pgd = pgd_offset_k(addr); + if (!pgd_present(*pgd)) + return false; + + p4d = p4d_offset(pgd, addr); + if (!p4d_present(*p4d)) + return false; + + pud = pud_offset(p4d, addr); + if (!pud_present(*pud)) + return false; + + pmd = pmd_offset(pud, addr); + if (!pmd_present(*pmd)) + return false; + + pte = pte_offset_kernel(pmd, addr); + return pte_present(*pte); +} --- a/arch/x86/include/asm/set_memory.h~arch-mm-make-kernel_page_present-always-available +++ a/arch/x86/include/asm/set_memory.h @@ -82,6 +82,7 @@ int set_pages_rw(struct page *page, int int set_direct_map_invalid_noflush(struct page *page); int set_direct_map_default_noflush(struct page *page); +bool kernel_page_present(struct page *page); extern int kernel_set_to_readonly; --- a/arch/x86/mm/pat/set_memory.c~arch-mm-make-kernel_page_present-always-available +++ a/arch/x86/mm/pat/set_memory.c @@ -2226,8 +2226,8 @@ void __kernel_map_pages(struct page *pag arch_flush_lazy_mmu_mode(); } +#endif /* CONFIG_DEBUG_PAGEALLOC */ -#ifdef CONFIG_HIBERNATION bool kernel_page_present(struct page *page) { unsigned int level; @@ -2239,8 +2239,6 @@ bool kernel_page_present(struct page *pa pte = lookup_address((unsigned long)page_address(page), &level); return (pte_val(*pte) & _PAGE_PRESENT); } -#endif /* CONFIG_HIBERNATION */ -#endif /* CONFIG_DEBUG_PAGEALLOC */ int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, unsigned numpages, unsigned long page_flags) --- a/include/linux/mm.h~arch-mm-make-kernel_page_present-always-available +++ a/include/linux/mm.h @@ -2949,16 +2949,9 @@ static inline void debug_pagealloc_unmap if (debug_pagealloc_enabled_static()) __kernel_map_pages(page, numpages, 0); } - -#ifdef CONFIG_HIBERNATION -extern bool kernel_page_present(struct page *page); -#endif /* CONFIG_HIBERNATION */ #else /* CONFIG_DEBUG_PAGEALLOC */ static inline void debug_pagealloc_map_pages(struct page *page, int numpages) {} static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages) {} -#ifdef CONFIG_HIBERNATION -static inline bool kernel_page_present(struct page *page) { return true; } -#endif /* CONFIG_HIBERNATION */ #endif /* CONFIG_DEBUG_PAGEALLOC */ #ifdef __HAVE_ARCH_GATE_AREA --- a/include/linux/set_memory.h~arch-mm-make-kernel_page_present-always-available +++ a/include/linux/set_memory.h @@ -23,6 +23,11 @@ static inline int set_direct_map_default { return 0; } + +static inline bool kernel_page_present(struct page *page) +{ + return true; +} #endif #ifndef set_mce_nospec _
