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Commit e651eab0 authored by Sricharan R's avatar Sricharan R Committed by Russell King
Browse files

ARM: 7677/1: LPAE: Fix mapping in alloc_init_section for unaligned addresses 



With LPAE enabled, alloc_init_section() does not map the entire
address space for unaligned addresses.

The issue also reproduced with CMA + LPAE. CMA tries to map 16MB
with page granularity mappings during boot. alloc_init_pte()
is called and out of 16MB, only 2MB gets mapped and rest remains
unaccessible.

Because of this OMAP5 boot is broken with CMA + LPAE enabled.
Fix the issue by ensuring that the entire addresses are
mapped.

Signed-off-by: default avatarR Sricharan <r.sricharan@ti.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoffer Dall <chris@cloudcar.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: default avatarLaura Abbott <lauraa@codeaurora.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarChristoffer Dall <chris@cloudcar.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 7fb476c2

arch/arm/mm/mmu.c

+47 −26
Original line number Diff line number Diff line
@@ -598,39 +598,60 @@ static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, 
	} while (pte++, addr += PAGE_SIZE, addr != end);

}



static void __init alloc_init_section(pud_t *pud, unsigned long addr,

static void __init map_init_section(pmd_t *pmd, unsigned long addr,

			unsigned long end, phys_addr_t phys,

			const struct mem_type *type)

{

	pmd_t *pmd = pmd_offset(pud, addr);



#ifndef CONFIG_ARM_LPAE

	/*

	 * Try a section mapping - end, addr and phys must all be aligned

	 * to a section boundary.  Note that PMDs refer to the individual

	 * L1 entries, whereas PGDs refer to a group of L1 entries making

	 * up one logical pointer to an L2 table.

	 * In classic MMU format, puds and pmds are folded in to

	 * the pgds. pmd_offset gives the PGD entry. PGDs refer to a

	 * group of L1 entries making up one logical pointer to

	 * an L2 table (2MB), where as PMDs refer to the individual

	 * L1 entries (1MB). Hence increment to get the correct

	 * offset for odd 1MB sections.

	 * (See arch/arm/include/asm/pgtable-2level.h)

	 */

	if (type->prot_sect && ((addr | end | phys) & ~SECTION_MASK) == 0) {

		pmd_t *p = pmd;



#ifndef CONFIG_ARM_LPAE

	if (addr & SECTION_SIZE)

		pmd++;

#endif



	do {

		*pmd = __pmd(phys | type->prot_sect);

		phys += SECTION_SIZE;

	} while (pmd++, addr += SECTION_SIZE, addr != end);



		flush_pmd_entry(p);

	} else {

	flush_pmd_entry(pmd);

}



static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,

				      unsigned long end, phys_addr_t phys,

				      const struct mem_type *type)

{

	pmd_t *pmd = pmd_offset(pud, addr);

	unsigned long next;



	do {

		/*

		 * No need to loop; pte's aren't interested in the

		 * individual L1 entries.

		 * With LPAE, we must loop over to map

		 * all the pmds for the given range.

		 */

		alloc_init_pte(pmd, addr, end, __phys_to_pfn(phys), type);

		next = pmd_addr_end(addr, end);



		/*

		 * Try a section mapping - addr, next and phys must all be

		 * aligned to a section boundary.

		 */

		if (type->prot_sect &&

				((addr | next | phys) & ~SECTION_MASK) == 0) {

			map_init_section(pmd, addr, next, phys, type);

		} else {

			alloc_init_pte(pmd, addr, next,

						__phys_to_pfn(phys), type);

		}



		phys += next - addr;



	} while (pmd++, addr = next, addr != end);

}



static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
@@ -641,7 +662,7 @@ static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr, 


	do {

		next = pud_addr_end(addr, end);

		alloc_init_section(pud, addr, next, phys, type);

		alloc_init_pmd(pud, addr, next, phys, type);

		phys += next - addr;

	} while (pud++, addr = next, addr != end);

}