Commit aa8c09be authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Catalin Marinas
Browse files

arm64: mmu: move TLB maintenance from callers to create_mapping_late() 



In preparation of refactoring the kernel mapping logic so that text regions
are never mapped writable, which would require adding explicit TLB
maintenance to new call sites of create_mapping_late() (which is currently
invoked twice from the same function), move the TLB maintenance from the
call site into create_mapping_late() itself, and change it from a full
TLB flush into a flush by VA, which is more appropriate here.

Also, given that create_mapping_late() has evolved into a routine that only
updates protection bits on existing mappings, rename it to
update_mapping_prot()

Reviewed-by: default avatarMark Rutland <mark.rutland@arm.com>
Tested-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 63d7c6af

arch/arm64/mm/mmu.c

+8 −8
Original line number Diff line number Diff line
@@ -319,17 +319,20 @@ void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys, 
			     pgd_pgtable_alloc, page_mappings_only);

}



static void create_mapping_late(phys_addr_t phys, unsigned long virt,

static void update_mapping_prot(phys_addr_t phys, unsigned long virt,

				phys_addr_t size, pgprot_t prot)

{

	if (virt < VMALLOC_START) {

		pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n",

		pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n",

			&phys, virt);

		return;

	}



	__create_pgd_mapping(init_mm.pgd, phys, virt, size, prot,

			     NULL, debug_pagealloc_enabled());



	/* flush the TLBs after updating live kernel mappings */

	flush_tlb_kernel_range(virt, virt + size);

}



static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, phys_addr_t end)
@@ -402,19 +405,16 @@ void mark_rodata_ro(void) 
	unsigned long section_size;



	section_size = (unsigned long)_etext - (unsigned long)_text;

	create_mapping_late(__pa_symbol(_text), (unsigned long)_text,

	update_mapping_prot(__pa_symbol(_text), (unsigned long)_text,

			    section_size, PAGE_KERNEL_ROX);

	/*

	 * mark .rodata as read only. Use __init_begin rather than __end_rodata

	 * to cover NOTES and EXCEPTION_TABLE.

	 */

	section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata;

	create_mapping_late(__pa_symbol(__start_rodata), (unsigned long)__start_rodata,

	update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata,

			    section_size, PAGE_KERNEL_RO);



	/* flush the TLBs after updating live kernel mappings */

	flush_tlb_all();



	debug_checkwx();

}

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