Commit 614dd058 authored by Russell King's avatar Russell King
Browse files

ARM: pgtable: collect up identity mapping functions 



We have two places where we create identity mappings - one when we bring
secondary CPUs online, and one where we setup some mappings for soft-
reboot.  Combine these two into a single implementation.  Also collect
the identity mapping deletion function.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 26bbf0b5

arch/arm/include/asm/pgtable.h

+3 −0
Original line number Diff line number Diff line
@@ -474,6 +474,9 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 


#define pgtable_cache_init() do { } while (0)



void identity_mapping_add(pgd_t *, unsigned long, unsigned long);

void identity_mapping_del(pgd_t *, unsigned long, unsigned long);



#endif /* !__ASSEMBLY__ */



#endif /* CONFIG_MMU */

arch/arm/kernel/smp.c

+0 −34
Original line number Diff line number Diff line
@@ -68,40 +68,6 @@ enum ipi_msg_type { 
	IPI_CPU_STOP,

};



static inline void identity_mapping_add(pgd_t *pgd, unsigned long start,

	unsigned long end)

{

	unsigned long addr, prot;

	pmd_t *pmd;



	prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE;

	if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())

		prot |= PMD_BIT4;



	for (addr = start & PGDIR_MASK; addr < end;) {

		pmd = pmd_offset(pgd + pgd_index(addr), addr);

		pmd[0] = __pmd(addr | prot);

		addr += SECTION_SIZE;

		pmd[1] = __pmd(addr | prot);

		addr += SECTION_SIZE;

		flush_pmd_entry(pmd);

	}

}



static inline void identity_mapping_del(pgd_t *pgd, unsigned long start,

	unsigned long end)

{

	unsigned long addr;

	pmd_t *pmd;



	for (addr = start & PGDIR_MASK; addr < end; addr += PGDIR_SIZE) {

		pmd = pmd_offset(pgd + pgd_index(addr), addr);

		pmd[0] = __pmd(0);

		pmd[1] = __pmd(0);

		clean_pmd_entry(pmd);

	}

}



int __cpuinit __cpu_up(unsigned int cpu)

{

	struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu);

arch/arm/mm/Makefile

+2 −2
Original line number Diff line number Diff line
@@ -5,8 +5,8 @@ 
obj-y				:= dma-mapping.o extable.o fault.o init.o \

				   iomap.o



obj-$(CONFIG_MMU)		+= fault-armv.o flush.o ioremap.o mmap.o \

				   pgd.o mmu.o vmregion.o

obj-$(CONFIG_MMU)		+= fault-armv.o flush.o idmap.o ioremap.o \

				   mmap.o pgd.o mmu.o vmregion.o



ifneq ($(CONFIG_MMU),y)

obj-y				+= nommu.o

arch/arm/mm/idmap.c

0 → 100644
+51 −0
Original line number Diff line number Diff line 
#include <linux/kernel.h>



#include <asm/cputype.h>

#include <asm/pgalloc.h>

#include <asm/pgtable.h>



void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end)

{

	unsigned long prot;



	prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE;

	if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())

		prot |= PMD_BIT4;



	for (addr &= PGDIR_MASK; addr < end;) {

		pmd_t *pmd = pmd_offset(pgd + pgd_index(addr), addr);

		pmd[0] = __pmd(addr | prot);

		addr += SECTION_SIZE;

		pmd[1] = __pmd(addr | prot);

		addr += SECTION_SIZE;

		flush_pmd_entry(pmd);

	}

}



#ifdef CONFIG_SMP

void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end)

{

	for (addr &= PGDIR_MASK; addr < end; addr += PGDIR_SIZE) {

		pmd_t *pmd = pmd_offset(pgd + pgd_index(addr), addr);

		pmd[0] = __pmd(0);

		pmd[1] = __pmd(0);

		clean_pmd_entry(pmd);

	}

}

#endif



/*

 * In order to soft-boot, we need to insert a 1:1 mapping in place of

 * the user-mode pages.  This will then ensure that we have predictable

 * results when turning the mmu off

 */

void setup_mm_for_reboot(char mode)

{

	/*

	 * We need to access to user-mode page tables here. For kernel threads

	 * we don't have any user-mode mappings so we use the context that we

	 * "borrowed".

	 */

	identity_mapping_add(current->active_mm->pgd, 0, TASK_SIZE);

	local_flush_tlb_all();

}

arch/arm/mm/mmu.c

+0 −35
Original line number Diff line number Diff line
@@ -1045,38 +1045,3 @@ void __init paging_init(struct machine_desc *mdesc) 
	empty_zero_page = virt_to_page(zero_page);

	__flush_dcache_page(NULL, empty_zero_page);

}
 


/*

 * In order to soft-boot, we need to insert a 1:1 mapping in place of

 * the user-mode pages.  This will then ensure that we have predictable

 * results when turning the mmu off

 */

void setup_mm_for_reboot(char mode)

{

	unsigned long base_pmdval;

	pgd_t *pgd;

	int i;



	/*

	 * We need to access to user-mode page tables here. For kernel threads

	 * we don't have any user-mode mappings so we use the context that we

	 * "borrowed".

	 */

	pgd = current->active_mm->pgd;



	base_pmdval = PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | PMD_TYPE_SECT;

	if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())

		base_pmdval |= PMD_BIT4;



	for (i = 0; i < FIRST_USER_PGD_NR + USER_PTRS_PER_PGD; i++, pgd++) {

		unsigned long pmdval = (i << PGDIR_SHIFT) | base_pmdval;

		pmd_t *pmd;



		pmd = pmd_off(pgd, i << PGDIR_SHIFT);

		pmd[0] = __pmd(pmdval);

		pmd[1] = __pmd(pmdval + (1 << (PGDIR_SHIFT - 1)));

		flush_pmd_entry(pmd);

	}



	local_flush_tlb_all();

}

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