| 40,11 → 40,28 |
|---|
| * They however, define the single interface. |
| */ |
| |
| /* |
| * Note on memory prefetching and updating memory mappings, also described in: |
| * AMD x86-64 Architecture Programmer's Manual, Volume 2, System Programming, |
| * 7.2.1 Special Coherency Considerations. |
| * |
| * The processor which modifies a page table mapping can access prefetched data |
| * from the old mapping. In order to prevent this, we place a memory barrier |
| * after a mapping is updated. |
| * |
| * We assume that the other processors are either not using the mapping yet |
| * (i.e. during the bootstrap) or are executing the TLB shootdown code. While |
| * we don't care much about the former case, the processors in the latter case |
| * will do an implicit serialization by virtue of running the TLB shootdown |
| * interrupt handler. |
| */ |
| |
| #include <mm/page.h> |
| #include <arch/mm/page.h> |
| #include <arch/mm/asid.h> |
| #include <mm/as.h> |
| #include <mm/frame.h> |
| #include <arch/barrier.h> |
| #include <arch/types.h> |
| #include <arch/asm.h> |
| #include <memstr.h> |
| 76,8 → 93,11 |
|---|
| cnt = length / PAGE_SIZE + (length % PAGE_SIZE > 0); |
| |
| for (i = 0; i < cnt; i++) |
| page_mapping_insert(AS_KERNEL, s + i * PAGE_SIZE, s + i * PAGE_SIZE, PAGE_NOT_CACHEABLE | PAGE_WRITE); |
| page_mapping_insert(AS_KERNEL, s + i * PAGE_SIZE, |
| s + i * PAGE_SIZE, PAGE_NOT_CACHEABLE | PAGE_WRITE); |
| |
| /* Repel prefetched accesses to the old mapping. */ |
| memory_barrier(); |
| } |
| |
| /** Insert mapping of page to frame. |
| 89,7 → 109,8 |
|---|
| * |
| * @param as Address space to wich page belongs. |
| * @param page Virtual address of the page to be mapped. |
| * @param frame Physical address of memory frame to which the mapping is done. |
| * @param frame Physical address of memory frame to which the mapping is |
| * done. |
| * @param flags Flags to be used for mapping. |
| */ |
| void page_mapping_insert(as_t *as, uintptr_t page, uintptr_t frame, int flags) |
| 98,6 → 119,9 |
|---|
| ASSERT(page_mapping_operations->mapping_insert); |
| |
| page_mapping_operations->mapping_insert(as, page, frame, flags); |
| |
| /* Repel prefetched accesses to the old mapping. */ |
| memory_barrier(); |
| } |
| |
| /** Remove mapping of page. |
| 117,6 → 141,9 |
|---|
| ASSERT(page_mapping_operations->mapping_remove); |
| |
| page_mapping_operations->mapping_remove(as, page); |
| |
| /* Repel prefetched accesses to the old mapping. */ |
| memory_barrier(); |
| } |
| |
| /** Find mapping for virtual page |
| 128,7 → 155,8 |
|---|
| * @param as Address space to wich page belongs. |
| * @param page Virtual page. |
| * |
| * @return NULL if there is no such mapping; requested mapping otherwise. |
| * @return NULL if there is no such mapping; requested mapping |
| * otherwise. |
| */ |
| pte_t *page_mapping_find(as_t *as, uintptr_t page) |
| { |