diff options
| -rw-r--r-- | src/arch/arm64/armv8/mmu.c | 34 | ||||
| -rw-r--r-- | src/arch/arm64/include/armv8/arch/mmu.h | 9 |
2 files changed, 43 insertions, 0 deletions
diff --git a/src/arch/arm64/armv8/mmu.c b/src/arch/arm64/armv8/mmu.c index a24e7c6fdd..48f77ace83 100644 --- a/src/arch/arm64/armv8/mmu.c +++ b/src/arch/arm64/armv8/mmu.c @@ -274,6 +274,40 @@ void mmu_init(void) TCR_TBI_USED); } +/* Func : mmu_save_context + * Desc : Save mmu context (registers and ttbr base). + */ +void mmu_save_context(struct mmu_context *mmu_context) +{ + assert(mmu_context); + + /* Back-up MAIR_ATTRIBUTES */ + mmu_context->mair = raw_read_mair_el3(); + + /* Back-up TCR value */ + mmu_context->tcr = raw_read_tcr_el3(); +} + +/* Func : mmu_restore_context + * Desc : Restore mmu context using input backed-up context + */ +void mmu_restore_context(const struct mmu_context *mmu_context) +{ + assert(mmu_context); + + /* Restore TTBR */ + raw_write_ttbr0_el3((uintptr_t)_ttb); + + /* Restore MAIR indices */ + raw_write_mair_el3(mmu_context->mair); + + /* Restore TCR flags */ + raw_write_tcr_el3(mmu_context->tcr); + + /* invalidate tlb since ttbr is updated. */ + tlb_invalidate_all(); +} + void mmu_enable(void) { if (((get_pte(_ttb) >> BLOCK_INDEX_SHIFT) & BLOCK_INDEX_MASK) diff --git a/src/arch/arm64/include/armv8/arch/mmu.h b/src/arch/arm64/include/armv8/arch/mmu.h index f0e551e52d..6c83749e95 100644 --- a/src/arch/arm64/include/armv8/arch/mmu.h +++ b/src/arch/arm64/include/armv8/arch/mmu.h @@ -148,8 +148,17 @@ #define TCR_TBI_USED (0x0 << TCR_TBI_SHIFT) #define TCR_TBI_IGNORED (0x1 << TCR_TBI_SHIFT) +struct mmu_context { + uint64_t mair; /* MAIR attributes */ + uint64_t tcr; /* TCR Attributes */ +}; + /* Initialize MMU registers and page table memory region. */ void mmu_init(void); +/* Desc : Save mmu context (registers and ttbr base/size). */ +void mmu_save_context(struct mmu_context *mmu_context); +/* Desc : Restore mmu context using input backed-up context */ +void mmu_restore_context(const struct mmu_context *mmu_context); /* Change a memory type for a range of bytes at runtime. */ void mmu_config_range(void *start, size_t size, uint64_t tag); /* Enable the MMU (need previous mmu_init() and configured ranges!). */ |