diff options
Diffstat (limited to 'kernel/memory')
| -rw-r--r-- | kernel/memory/paging.c | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/kernel/memory/paging.c b/kernel/memory/paging.c index 838f6fd..2709050 100644 --- a/kernel/memory/paging.c +++ b/kernel/memory/paging.c @@ -522,31 +522,40 @@ void paging_init(void) __asm__ volatile("mov %0, %%cr3" ::"r"(kernel_pml4) : "memory"); } +static inline void *page_align(void *addr) +{ + uintptr_t a = (uintptr_t)addr; + a /= PAGE_SIZE; + a *= PAGE_SIZE; + return (void *)a; +} + void *mem_mapaddr(mem_ctx_t ctx, void *phys, void *virt, size_t len, unsigned int flags) { long pages; - int alloc = 0; + ptrdiff_t error; + void *aligned_phys; - pages = (len + PAGE_SIZE - 1) / PAGE_SIZE; - len += (PAGE_SIZE - len) % PAGE_SIZE; + // get length and physical page aligned address + aligned_phys = page_align(phys); + error = (char *)phys - (char *)aligned_phys; + len += error; + pages = len / PAGE_SIZE + 1; - if (virt == NULL) { + // get page aligned (or allocate) vitural address + if (virt == NULL) virt = virtaddr_alloc(ctx->virtctx, pages); - alloc = 1; - } - if (virt == NULL) return NULL; - if (map_pages((volatile struct pml4e *)ctx->pml4, virt, phys, + if (map_pages((volatile struct pml4e *)ctx->pml4, virt, aligned_phys, F_WRITEABLE | flags, pages)) { - if (alloc) - virtaddr_free(ctx->virtctx, virt); + virtaddr_free(ctx->virtctx, virt); return NULL; } - return (char *)virt; + return (char *)virt + error; } void mem_unmapaddr(mem_ctx_t ctx, void *virt) |