Commit 32a0de88 authored by Mike Rapoport's avatar Mike Rapoport Committed by Linus Torvalds
Browse files

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@kernel.org


Signed-off-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5d6ad668

arch/arm64/include/asm/cacheflush.h

+1 −0
Original line number Diff line number Diff line
@@ -140,6 +140,7 @@ int set_memory_valid(unsigned long addr, int numpages, int enable); 


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>

arch/arm64/mm/pageattr.c

+1 −3
Original line number Diff line number Diff line
@@ -186,8 +186,8 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) 


	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 *page) 
	ptep = pte_offset_kernel(pmdp, addr);

	return pte_valid(READ_ONCE(*ptep));

}
 
#endif /* CONFIG_HIBERNATION */

#endif /* CONFIG_DEBUG_PAGEALLOC */

arch/riscv/include/asm/set_memory.h

+1 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; } 


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__ */

arch/riscv/mm/pageattr.c

+29 −0
Original line number Diff line number Diff line
@@ -198,3 +198,32 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) 
			     __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);

}

arch/x86/include/asm/set_memory.h

+1 −0
Original line number Diff line number Diff line
@@ -82,6 +82,7 @@ int set_pages_rw(struct page *page, int numpages); 


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;