diff options
Diffstat (limited to 'src/arch/arm64/armv8')
| -rw-r--r-- | src/arch/arm64/armv8/cpu.S | 15 | ||||
| -rw-r--r-- | src/arch/arm64/armv8/mmu.c | 14 |
2 files changed, 15 insertions, 14 deletions
diff --git a/src/arch/arm64/armv8/cpu.S b/src/arch/arm64/armv8/cpu.S index 1bb8c838ad..935f1fe7bd 100644 --- a/src/arch/arm64/armv8/cpu.S +++ b/src/arch/arm64/armv8/cpu.S @@ -15,6 +15,7 @@ */ #include <arch/asm.h> +#include <arch/cache.h> .macro dcache_apply_all crm dsb sy @@ -83,6 +84,20 @@ ENTRY(dcache_clean_invalidate_all) dcache_apply_all crm=cisw ENDPROC(dcache_clean_invalidate_all) +/* This must be implemented in assembly to ensure there are no accesses to + memory (e.g. the stack) in between disabling and flushing the cache. */ +ENTRY(mmu_disable) + str x30, [sp, #-0x8] + mrs x0, sctlr_el3 + mov x1, #~(SCTLR_C | SCTLR_M) + and x0, x0, x1 + msr sctlr_el3, x0 + isb + bl dcache_clean_invalidate_all + ldr x30, [sp, #-0x8] + ret +ENDPROC(mmu_disable) + /* * Bring an ARMv8 processor we just gained control of (e.g. from IROM) into a * known state regarding caches/SCTLR/PSTATE. Completely invalidates diff --git a/src/arch/arm64/armv8/mmu.c b/src/arch/arm64/armv8/mmu.c index 48f77ace83..606a9b30ad 100644 --- a/src/arch/arm64/armv8/mmu.c +++ b/src/arch/arm64/armv8/mmu.c @@ -321,17 +321,3 @@ void mmu_enable(void) raw_write_sctlr_el3(sctlr); isb(); } - -/* - * CAUTION: This implementation assumes that coreboot never uses non-identity - * page tables for pages containing executed code. If you ever want to violate - * this assumption, have fun figuring out the associated problems on your own. - */ -void mmu_disable(void) -{ - dcache_clean_invalidate_all(); - uint32_t sctlr = raw_read_sctlr_el3(); - sctlr &= ~(SCTLR_C | SCTLR_M); - raw_write_sctlr_el3(sctlr); - isb(); -} |