Index: generic/include/mm/as.h =================================================================== --- generic/include/mm/as.h (revision a60c748773e33375d25f66224916e5a8e7733d35) +++ generic/include/mm/as.h (revision 6a3c9a77923487a0b7ff489449084ef0796d88ef) @@ -66,5 +66,4 @@ size_t size; /**< Size of this area in multiples of PAGE_SIZE. */ __address base; /**< Base address of this area. */ - index_t *mapping; /**< Map of physical frame numbers mapped to virtual page numbers in this area. */ }; @@ -77,5 +76,5 @@ */ struct as { - /** Protected by asidlock. Must be acquired before as-> lock. */ + /** Protected by asidlock. Must be acquired before as->lock. */ link_t as_with_asid_link; @@ -88,5 +87,5 @@ extern as_t * as_create(pte_t *ptl0, int flags); extern as_area_t *as_area_create(as_t *as, as_area_type_t type, size_t size, __address base); -extern void as_area_set_mapping(as_area_t *a, index_t vpn, index_t pfn); +extern void as_set_mapping(as_t *as, __address page, __address frame); extern int as_page_fault(__address page); extern void as_install(as_t *m); Index: generic/src/main/kinit.c =================================================================== --- generic/src/main/kinit.c (revision a60c748773e33375d25f66224916e5a8e7733d35) +++ generic/src/main/kinit.c (revision 6a3c9a77923487a0b7ff489449084ef0796d88ef) @@ -72,6 +72,7 @@ as_t *as; as_area_t *a; - index_t frame, frames; - index_t pfn; + __address frame; + count_t frames; + int i; task_t *u; @@ -161,5 +162,5 @@ */ - frame = KA2PA(config.init_addr) / FRAME_SIZE; + frame = KA2PA(config.init_addr); frames = config.init_size / FRAME_SIZE; if (config.init_size % FRAME_SIZE > 0) @@ -170,7 +171,4 @@ panic("as_area_create: text\n"); - for (pfn = 0; pfn < frames; pfn++) - as_area_set_mapping(a, pfn, frame + pfn); - /* * Create the data as_area. @@ -179,4 +177,11 @@ if (!a) panic("as_area_create: stack\n"); + + /* + * Initialize text area mapping. + */ + for (i = 0; i < frames; i++) + as_set_mapping(as, UTEXT_ADDRESS + i * PAGE_SIZE, frame + i * FRAME_SIZE); + thread_ready(t); Index: generic/src/mm/as.c =================================================================== --- generic/src/mm/as.c (revision a60c748773e33375d25f66224916e5a8e7733d35) +++ generic/src/mm/as.c (revision 6a3c9a77923487a0b7ff489449084ef0796d88ef) @@ -60,11 +60,5 @@ #define KAS_INDICES (1+(KAS_END_INDEX-KAS_START_INDEX)) -/* - * Here we assume that PFN (Physical Frame Number) space - * is smaller than the width of index_t. UNALLOCATED_PFN - * can be then used to mark mappings wich were not - * yet allocated a physical frame. - */ -#define UNALLOCATED_PFN ((index_t) -1) +static int get_area_flags(as_area_t *a); /** Create address space. */ @@ -134,24 +128,5 @@ a = (as_area_t *) malloc(sizeof(as_area_t)); - if (a) { - int i; - - a->mapping = (index_t *) malloc(size * sizeof(index_t)); - if (!a->mapping) { - free(a); - spinlock_unlock(&as->lock); - interrupts_restore(ipl); - return NULL; - } - - for (i=0; imapping[i] = UNALLOCATED_PFN; - } - + if (a) { spinlock_initialize(&a->lock, "as_area_lock"); @@ -162,5 +137,4 @@ list_append(&a->link, &as->as_area_head); - } @@ -171,26 +145,50 @@ } -/** Load mapping for address space area. - * - * Initialize a->mapping. - * - * @param a Target address space area. - * @param vpn Page number relative to area start. - * @param pfn Frame number to map. - */ -void as_area_set_mapping(as_area_t *a, index_t vpn, index_t pfn) -{ - ASSERT(vpn < a->size); - ASSERT(a->mapping[vpn] == UNALLOCATED_PFN); - ASSERT(pfn != UNALLOCATED_PFN); - +/** Initialize mapping for one page of address space. + * + * This functions maps 'page' to 'frame' according + * to attributes of the address space area to + * wich 'page' belongs. + * + * @param a Target address space. + * @param page Virtual page within the area. + * @param frame Physical frame to which page will be mapped. + */ +void as_set_mapping(as_t *as, __address page, __address frame) +{ + as_area_t *a, *area = NULL; + link_t *cur; ipl_t ipl; ipl = interrupts_disable(); - spinlock_lock(&a->lock); - - a->mapping[vpn] = pfn; - - spinlock_unlock(&a->lock); + spinlock_lock(&as->lock); + + /* + * First, try locate an area. + */ + for (cur = as->as_area_head.next; cur != &as->as_area_head; cur = cur->next) { + a = list_get_instance(cur, as_area_t, link); + spinlock_lock(&a->lock); + + if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) { + area = a; + break; + } + + spinlock_unlock(&a->lock); + } + + if (!area) { + panic("page not part of any as_area\n"); + } + + /* + * Note: area->lock is held. + */ + + page_mapping_insert(page, as->asid, frame, get_area_flags(area), (__address) as->ptl0); + + spinlock_unlock(&area->lock); + spinlock_unlock(&as->lock); interrupts_restore(ipl); } @@ -207,8 +205,6 @@ int as_page_fault(__address page) { - int flags; link_t *cur; as_area_t *a, *area = NULL; - index_t vpn; __address frame; @@ -229,6 +225,4 @@ * TODO: access checking */ - - vpn = (page - a->base) / PAGE_SIZE; area = a; break; @@ -252,16 +246,73 @@ /* - * Decide if a frame needs to be allocated. - * If so, allocate it and adjust area->mapping map. - */ - if (area->mapping[vpn] == UNALLOCATED_PFN) { - frame = frame_alloc(0, ONE_FRAME, NULL); - memsetb(PA2KA(frame), FRAME_SIZE, 0); - area->mapping[vpn] = frame / FRAME_SIZE; - ASSERT(area->mapping[vpn] != UNALLOCATED_PFN); - } else - frame = area->mapping[vpn] * FRAME_SIZE; - - switch (area->type) { + * In general, there can be several reasons that + * can have caused this fault. + * + * - non-existent mapping: the area is a scratch + * area (e.g. stack) and so far has not been + * allocated a frame for the faulting page + * + * - non-present mapping: another possibility, + * currently not implemented, would be frame + * reuse; when this becomes a possibility, + * do not forget to distinguish between + * the different causes + */ + frame = frame_alloc(0, ONE_FRAME, NULL); + memsetb(PA2KA(frame), FRAME_SIZE, 0); + + /* + * Map 'page' to 'frame'. + * Note that TLB shootdown is not attempted as only new information is being + * inserted into page tables. + */ + page_mapping_insert(page, AS->asid, frame, get_area_flags(area), (__address) AS->ptl0); + + spinlock_unlock(&area->lock); + spinlock_unlock(&AS->lock); + + return 1; +} + +/** Install address space on CPU. + * + * @param as Address space. + */ +void as_install(as_t *as) +{ + ipl_t ipl; + + asid_install(as); + + ipl = interrupts_disable(); + spinlock_lock(&as->lock); + ASSERT(as->ptl0); + SET_PTL0_ADDRESS(as->ptl0); + spinlock_unlock(&as->lock); + interrupts_restore(ipl); + + /* + * Perform architecture-specific steps. + * (e.g. write ASID to hardware register etc.) + */ + as_install_arch(as); + + AS = as; +} + +/** Compute flags for virtual address translation subsytem. + * + * The address space area must be locked. + * Interrupts must be disabled. + * + * @param a Address space area. + * + * @return Flags to be used in page_mapping_insert(). + */ +int get_area_flags(as_area_t *a) +{ + int flags; + + switch (a->type) { case AS_AREA_TEXT: flags = PAGE_EXEC | PAGE_READ | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE; @@ -272,43 +323,7 @@ break; default: - panic("unexpected as_area_type_t %d", area->type); - } - - /* - * Map 'page' to 'frame'. - * Note that TLB shootdown is not attempted as only new information is being - * inserted into page tables. - */ - page_mapping_insert(page, AS->asid, frame, flags, (__address) AS->ptl0); - - spinlock_unlock(&area->lock); - spinlock_unlock(&AS->lock); - - return 1; -} - -/** Install address space on CPU. - * - * @param as Address space. - */ -void as_install(as_t *as) -{ - ipl_t ipl; - - asid_install(as); - - ipl = interrupts_disable(); - spinlock_lock(&as->lock); - ASSERT(as->ptl0); - SET_PTL0_ADDRESS(as->ptl0); - spinlock_unlock(&as->lock); - interrupts_restore(ipl); - - /* - * Perform architecture-specific steps. - * (e.g. write ASID to hardware register etc.) - */ - as_install_arch(as); - - AS = as; -} + panic("unexpected as_area_type_t %d", a->type); + } + + return flags; +}