diff options
Diffstat (limited to 'arch/arm/mm/idmap.c')
| -rw-r--r-- | arch/arm/mm/idmap.c | 55 |
1 files changed, 39 insertions, 16 deletions
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c index feacf4c7671..c447ec70e86 100644 --- a/arch/arm/mm/idmap.c +++ b/arch/arm/mm/idmap.c @@ -1,12 +1,21 @@ +#include <linux/module.h> #include <linux/kernel.h> +#include <linux/slab.h> #include <asm/cputype.h> #include <asm/idmap.h> #include <asm/pgalloc.h> #include <asm/pgtable.h> #include <asm/sections.h> +#include <asm/system_info.h> +/* + * Note: accesses outside of the kernel image and the identity map area + * are not supported on any CPU using the idmap tables as its current + * page tables. + */ pgd_t *idmap_pgd; +phys_addr_t (*arch_virt_to_idmap) (unsigned long x); #ifdef CONFIG_ARM_LPAE static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end, @@ -21,6 +30,13 @@ static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end, pr_warning("Failed to allocate identity pmd.\n"); return; } + /* + * Copy the original PMD to ensure that the PMD entries for + * the kernel image are preserved. + */ + if (!pud_none(*pud)) + memcpy(pmd, pmd_offset(pud, 0), + PTRS_PER_PMD * sizeof(pmd_t)); pud_populate(&init_mm, pud, pmd); pmd += pmd_index(addr); } else @@ -58,11 +74,18 @@ static void idmap_add_pud(pgd_t *pgd, unsigned long addr, unsigned long end, } while (pud++, addr = next, addr != end); } -static void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end) +static void identity_mapping_add(pgd_t *pgd, const char *text_start, + const char *text_end, unsigned long prot) { - unsigned long prot, next; + unsigned long addr, end; + unsigned long next; + + addr = virt_to_idmap(text_start); + end = virt_to_idmap(text_end); + pr_info("Setting up static identity map for 0x%lx - 0x%lx\n", addr, end); + + prot |= PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF; - prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF; if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale()) prot |= PMD_BIT4; @@ -77,19 +100,15 @@ extern char __idmap_text_start[], __idmap_text_end[]; static int __init init_static_idmap(void) { - phys_addr_t idmap_start, idmap_end; - idmap_pgd = pgd_alloc(&init_mm); if (!idmap_pgd) return -ENOMEM; - /* Add an identity mapping for the physical address of the section. */ - idmap_start = virt_to_phys((void *)__idmap_text_start); - idmap_end = virt_to_phys((void *)__idmap_text_end); + identity_mapping_add(idmap_pgd, __idmap_text_start, + __idmap_text_end, 0); - pr_info("Setting up static identity map for 0x%llx - 0x%llx\n", - (long long)idmap_start, (long long)idmap_end); - identity_mapping_add(idmap_pgd, idmap_start, idmap_end); + /* Flush L1 for the hardware to see this page table content */ + flush_cache_louis(); return 0; } @@ -102,12 +121,16 @@ early_initcall(init_static_idmap); */ void setup_mm_for_reboot(void) { - /* Clean and invalidate L1. */ - flush_cache_all(); - /* Switch to the identity mapping. */ cpu_switch_mm(idmap_pgd, &init_mm); - - /* Flush the TLB. */ + local_flush_bp_all(); + +#ifdef CONFIG_CPU_HAS_ASID + /* + * We don't have a clean ASID for the identity mapping, which + * may clash with virtual addresses of the previous page tables + * and therefore potentially in the TLB. + */ local_flush_tlb_all(); +#endif } |