diff options
| author | Ian Moffett <[email protected]> | 2024-06-02 21:42:28 -0400 |
|---|---|---|
| committer | Ian Moffett <[email protected]> | 2024-06-02 21:54:36 -0400 |
| commit | 312b5687c905a7614cdd1e5080a69bd12cbc95b4 (patch) | |
| tree | 7ebec27a6904e191c60363cd7325b34a832b45e5 | |
| parent | d42858a660a2253e8fbb360f662487e5d34b33b6 (diff) | |
kernel/amd64: pmap: Add helper to set cache policy
Signed-off-by: Ian Moffett <[email protected]>
| -rw-r--r-- | sys/arch/amd64/amd64/pmap.c | 32 | ||||
| -rw-r--r-- | sys/include/vm/pmap.h | 10 |
2 files changed, 42 insertions, 0 deletions
diff --git a/sys/arch/amd64/amd64/pmap.c b/sys/arch/amd64/amd64/pmap.c index e95471b..9443727 100644 --- a/sys/arch/amd64/amd64/pmap.c +++ b/sys/arch/amd64/amd64/pmap.c @@ -255,6 +255,38 @@ pmap_modify_tbl(struct vm_ctx *ctx, struct vas vas, vaddr_t va, size_t val) } int +pmap_set_cache(struct vm_ctx *ctx, struct vas vas, vaddr_t va, int type) +{ + uintptr_t *tbl; + int status; + size_t idx; + + if ((status = pmap_get_tbl(ctx, vas, va, false, &tbl)) != 0) { + return status; + } + + idx = pmap_get_level_index(1, va); + + /* Set the policy based on the type */ + 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: + /* Invalid type */ + return 1; + } + + pmap_flush(va); + return 0; +} + +int pmap_map(struct vm_ctx *ctx, struct vas vas, vaddr_t va, paddr_t pa, vm_prot_t prot) { diff --git a/sys/include/vm/pmap.h b/sys/include/vm/pmap.h index 8c69372..cb18885 100644 --- a/sys/include/vm/pmap.h +++ b/sys/include/vm/pmap.h @@ -54,6 +54,10 @@ #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 */ + #define is_vas_valid(vas) (vas.top_level != 0) /* @@ -67,6 +71,12 @@ struct vm_ctx { }; /* + * Mark a virtual address with a specific caching + * type. + */ +int pmap_set_cache(struct vm_ctx *, struct vas, vaddr_t, int); + +/* * Create a virtual address space * and return the descriptor. */ |