diff options
| -rw-r--r-- | sys/arch/amd64/amd64/pmap.c | 29 | ||||
| -rw-r--r-- | sys/include/vm/pmap.h | 10 |
2 files changed, 39 insertions, 0 deletions
diff --git a/sys/arch/amd64/amd64/pmap.c b/sys/arch/amd64/amd64/pmap.c index 0f41e7a..1d95ec4 100644 --- a/sys/arch/amd64/amd64/pmap.c +++ b/sys/arch/amd64/amd64/pmap.c @@ -274,3 +274,32 @@ pmap_unmap(struct vas vas, vaddr_t va) { return pmap_update_tbl(vas, va, 0); } + +int +pmap_set_cache(struct vas vas, vaddr_t va, int type) +{ + uintptr_t *tbl; + int status; + size_t idx; + + if ((status = pmap_get_tbl(vas, va, false, &tbl)) != 0) + return status; + + idx = pmap_get_level_index(1, va); + + /* Set the caching policy */ + switch (type) { + case VM_CACHE_UC: + tbl[idx] |= PTE_PCD; + tbl[idx] &= ~PTE_PWT; + break; + case VM_CACHE_WT: + tbl[idx] &= ~PTE_PCD; + tbl[idx] |= PTE_PWT; + break; + default: + return -EINVAL; + } + + return 0; +} diff --git a/sys/include/vm/pmap.h b/sys/include/vm/pmap.h index 4cd334c..741eaf2 100644 --- a/sys/include/vm/pmap.h +++ b/sys/include/vm/pmap.h @@ -39,6 +39,10 @@ #define PROT_EXEC BIT(1) /* Executable */ #define PROT_USER BIT(2) /* User accessible */ +/* Caching types */ +#define VM_CACHE_UC 0x00000U /* Uncachable */ +#define VM_CACHE_WT 0x00001U /* Write-through */ + typedef uint32_t vm_prot_t; /* @@ -71,4 +75,10 @@ int pmap_map(struct vas vas, vaddr_t va, paddr_t pa, vm_prot_t prot); */ int pmap_unmap(struct vas vas, vaddr_t va); +/* + * Mark a virtual address with a specific + * caching type. + */ +int pmap_set_cache(struct vas vas, vaddr_t va, int type); + #endif /* !_VM_PMAP_H_ */ |