From 9e9a367c29cebd25a356d53414612e115efdadcf Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Sun, 20 Jan 2013 18:43:10 -0500 Subject: [PATCH] ARM: Section based HYP idmap Add a method (hyp_idmap_setup) to populate a hyp pgd with an identity mapping of the code contained in the .hyp.idmap.text section. Offer a method to drop this identity mapping through hyp_idmap_teardown. Make all the above depend on CONFIG_ARM_VIRT_EXT and CONFIG_ARM_LPAE. Reviewed-by: Will Deacon Reviewed-by: Marcelo Tosatti Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/idmap.h | 1 + arch/arm/include/asm/pgtable-3level-hwdef.h | 1 + arch/arm/kernel/vmlinux.lds.S | 6 +++- arch/arm/mm/idmap.c | 55 +++++++++++++++++++++++------ 4 files changed, 51 insertions(+), 12 deletions(-) diff --git a/arch/arm/include/asm/idmap.h b/arch/arm/include/asm/idmap.h index bf863ed..1a66f907 100644 --- a/arch/arm/include/asm/idmap.h +++ b/arch/arm/include/asm/idmap.h @@ -8,6 +8,7 @@ #define __idmap __section(.idmap.text) noinline notrace extern pgd_t *idmap_pgd; +extern pgd_t *hyp_pgd; void setup_mm_for_reboot(void); diff --git a/arch/arm/include/asm/pgtable-3level-hwdef.h b/arch/arm/include/asm/pgtable-3level-hwdef.h index d795282..a2d404e 100644 --- a/arch/arm/include/asm/pgtable-3level-hwdef.h +++ b/arch/arm/include/asm/pgtable-3level-hwdef.h @@ -44,6 +44,7 @@ #define PMD_SECT_XN (_AT(pmdval_t, 1) << 54) #define PMD_SECT_AP_WRITE (_AT(pmdval_t, 0)) #define PMD_SECT_AP_READ (_AT(pmdval_t, 0)) +#define PMD_SECT_AP1 (_AT(pmdval_t, 1) << 6) #define PMD_SECT_TEX(x) (_AT(pmdval_t, 0)) /* diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index 11c1785..b571484 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -19,7 +19,11 @@ ALIGN_FUNCTION(); \ VMLINUX_SYMBOL(__idmap_text_start) = .; \ *(.idmap.text) \ - VMLINUX_SYMBOL(__idmap_text_end) = .; + VMLINUX_SYMBOL(__idmap_text_end) = .; \ + ALIGN_FUNCTION(); \ + VMLINUX_SYMBOL(__hyp_idmap_text_start) = .; \ + *(.hyp.idmap.text) \ + VMLINUX_SYMBOL(__hyp_idmap_text_end) = .; #ifdef CONFIG_HOTPLUG_CPU #define ARM_CPU_DISCARD(x) diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c index 99db769..2dffc01 100644 --- a/arch/arm/mm/idmap.c +++ b/arch/arm/mm/idmap.c @@ -1,4 +1,6 @@ +#include #include +#include #include #include @@ -6,6 +8,7 @@ #include #include #include +#include pgd_t *idmap_pgd; @@ -59,11 +62,17 @@ 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_phys(text_start); + end = virt_to_phys(text_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; @@ -74,28 +83,52 @@ static void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long e } while (pgd++, addr = next, addr != end); } +#if defined(CONFIG_ARM_VIRT_EXT) && defined(CONFIG_ARM_LPAE) +pgd_t *hyp_pgd; + +extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[]; + +static int __init init_static_idmap_hyp(void) +{ + hyp_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL); + if (!hyp_pgd) + return -ENOMEM; + + pr_info("Setting up static HYP identity map for 0x%p - 0x%p\n", + __hyp_idmap_text_start, __hyp_idmap_text_end); + identity_mapping_add(hyp_pgd, __hyp_idmap_text_start, + __hyp_idmap_text_end, PMD_SECT_AP1); + + return 0; +} +#else +static int __init init_static_idmap_hyp(void) +{ + return 0; +} +#endif + extern char __idmap_text_start[], __idmap_text_end[]; static int __init init_static_idmap(void) { - phys_addr_t idmap_start, idmap_end; + int ret; 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); + pr_info("Setting up static identity map for 0x%p - 0x%p\n", + __idmap_text_start, __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); + ret = init_static_idmap_hyp(); /* Flush L1 for the hardware to see this page table content */ flush_cache_louis(); - return 0; + return ret; } early_initcall(init_static_idmap); -- 2.7.4