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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: Russell King <rmk+kernel@arm.linux.org.uk>
hifive-unleashed-5.1
Russell King 2010-11-21 11:41:57 +00:00
parent 26bbf0b57a
commit 614dd0585f
5 changed files with 56 additions and 71 deletions
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3
arch/arm/include/asm/pgtable.h
View File

@ -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 */

34
arch/arm/kernel/smp.c
View File

@ -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);

4
arch/arm/mm/Makefile
View File

@ -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

51
arch/arm/mm/idmap.c 100644
View File

@ -0,0 +1,51 @@
#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();
}

35
arch/arm/mm/mmu.c
View File

@ -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();
}