/* * linux/arch/arm/mm/init.c * * Copyright (C) 1995-2000 Russell King * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef CONFIG_DISCONTIGMEM #define NR_NODES 1 #else #define NR_NODES 4 #endif #ifdef CONFIG_CPU_32 #define TABLE_OFFSET (PTRS_PER_PTE) #else #define TABLE_OFFSET 0 #endif #define TABLE_SIZE ((TABLE_OFFSET + PTRS_PER_PTE) * sizeof(void *)) static unsigned long totalram_pages; pgd_t swapper_pg_dir[PTRS_PER_PGD]; extern char _stext, _text, _etext, _end, __init_begin, __init_end; /* * The sole use of this is to pass memory configuration * data from paging_init to mem_init. */ static struct meminfo __initdata meminfo; /* * empty_bad_page is the page that is used for page faults when * linux is out-of-memory. Older versions of linux just did a * do_exit(), but using this instead means there is less risk * for a process dying in kernel mode, possibly leaving a inode * unused etc.. * * empty_bad_pte_table is the accompanying page-table: it is * initialized to point to BAD_PAGE entries. * * empty_zero_page is a special page that is used for * zero-initialized data and COW. */ struct page *empty_zero_page; struct page *empty_bad_page; pte_t *empty_bad_pte_table; pte_t *get_bad_pte_table(void) { pte_t v; int i; v = pte_mkdirty(mk_pte(empty_bad_page, PAGE_SHARED)); for (i = 0; i < PTRS_PER_PTE; i++) set_pte(empty_bad_pte_table + i, v); return empty_bad_pte_table; } void __handle_bad_pmd(pmd_t *pmd) { pmd_ERROR(*pmd); #ifdef CONFIG_DEBUG_ERRORS __backtrace(); #endif set_pmd(pmd, mk_user_pmd(get_bad_pte_table())); } void __handle_bad_pmd_kernel(pmd_t *pmd) { pmd_ERROR(*pmd); #ifdef CONFIG_DEBUG_ERRORS __backtrace(); #endif set_pmd(pmd, mk_kernel_pmd(get_bad_pte_table())); } #ifndef CONFIG_NO_PGT_CACHE struct pgtable_cache_struct quicklists; int do_check_pgt_cache(int low, int high) { int freed = 0; if(pgtable_cache_size > high) { do { if(pgd_quicklist) { free_pgd_slow(get_pgd_fast()); freed++; } if(pmd_quicklist) { free_pmd_slow(get_pmd_fast()); freed++; } if(pte_quicklist) { free_pte_slow(get_pte_fast()); freed++; } } while(pgtable_cache_size > low); } return freed; } #else int do_check_pgt_cache(int low, int high) { return 0; } #endif void show_mem(void) { int free = 0, total = 0, reserved = 0; int shared = 0, cached = 0, node; printk("Mem-info:\n"); show_free_areas(); printk("Free swap: %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10)); for (node = 0; node < numnodes; node++) { struct page *page, *end; page = NODE_MEM_MAP(node); end = page + NODE_DATA(node)->node_size; do { /* This is currently broken * PG_skip is used on sparc/sparc64 architectures to "skip" certain * parts of the address space. * * #define PG_skip 10 * #define PageSkip(page) (machine_is_riscpc() && test_bit(PG_skip, &(page)->flags)) * if (PageSkip(page)) { * page = page->next_hash; * if (page == NULL) * break; * } */ total++; if (PageReserved(page)) reserved++; else if (PageSwapCache(page)) cached++; else if (!page_count(page)) free++; else shared += atomic_read(&page->count) - 1; page++; } while (page < end); } printk("%d pages of RAM\n", total); printk("%d free pages\n", free); printk("%d reserved pages\n", reserved); printk("%d pages shared\n", shared); printk("%d pages swap cached\n", cached); #ifndef CONFIG_NO_PGT_CACHE printk("%ld page tables cached\n", pgtable_cache_size); #endif show_buffers(); } struct node_info { unsigned int start; unsigned int end; int bootmap_pages; }; #define O_PFN_DOWN(x) ((x) >> PAGE_SHIFT) #define V_PFN_DOWN(x) O_PFN_DOWN(__pa(x)) #define O_PFN_UP(x) (PAGE_ALIGN(x) >> PAGE_SHIFT) #define V_PFN_UP(x) O_PFN_UP(__pa(x)) #define PFN_SIZE(x) ((x) >> PAGE_SHIFT) #define PFN_RANGE(s,e) PFN_SIZE(PAGE_ALIGN((unsigned long)(e)) - \ (((unsigned long)(s)) & PAGE_MASK)) /* * FIXME: We really want to avoid allocating the bootmap bitmap * over the top of the initrd. Hopefully, this is located towards * the start of a bank, so if we allocate the bootmap bitmap at * the end, we won't clash. */ static unsigned int __init find_bootmap_pfn(int node, struct meminfo *mi, unsigned int bootmap_pages) { unsigned int start_pfn, bank, bootmap_pfn; start_pfn = V_PFN_UP(&_end); bootmap_pfn = 0; for (bank = 0; bank < mi->nr_banks; bank ++) { unsigned int start, end; if (mi->bank[bank].node != node) continue; start = O_PFN_UP(mi->bank[bank].start); end = O_PFN_DOWN(mi->bank[bank].size + mi->bank[bank].start); if (end < start_pfn) continue; if (start < start_pfn) start = start_pfn; if (end <= start) continue; if (end - start >= bootmap_pages) { bootmap_pfn = start; break; } } if (bootmap_pfn == 0) BUG(); return bootmap_pfn; } /* * Scan the memory info structure and pull out: * - the end of memory * - the number of nodes * - the pfn range of each node * - the number of bootmem bitmap pages */ static unsigned int __init find_memend_and_nodes(struct meminfo *mi, struct node_info *np) { unsigned int i, bootmem_pages = 0, memend_pfn = 0; for (i = 0; i < NR_NODES; i++) { np[i].start = -1U; np[i].end = 0; np[i].bootmap_pages = 0; } for (i = 0; i < mi->nr_banks; i++) { unsigned long start, end; int node; if (mi->bank[i].size == 0) { /* * Mark this bank with an invalid node number */ mi->bank[i].node = -1; continue; } node = mi->bank[i].node; if (node >= numnodes) { numnodes = node + 1; /* * Make sure we haven't exceeded the maximum number * of nodes that we have in this configuration. If * we have, we're in trouble. (maybe we ought to * limit, instead of bugging?) */ if (numnodes > NR_NODES) BUG(); } /* * Get the start and end pfns for this bank */ start = O_PFN_UP(mi->bank[i].start); end = O_PFN_DOWN(mi->bank[i].start + mi->bank[i].size); if (np[node].start > start) np[node].start = start; if (np[node].end < end) np[node].end = end; if (memend_pfn < end) memend_pfn = end; } /* * Calculate the number of pages we require to * store the bootmem bitmaps. */ for (i = 0; i < numnodes; i++) { if (np[i].end == 0) continue; np[i].bootmap_pages = bootmem_bootmap_pages(np[i].end - np[i].start); bootmem_pages += np[i].bootmap_pages; } /* * This doesn't seem to be used by the Linux memory * manager any more. If we can get rid of it, we * also get rid of some of the stuff above as well. */ max_low_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET); mi->end = memend_pfn << PAGE_SHIFT; return bootmem_pages; } static int __init check_initrd(struct meminfo *mi) { int initrd_node = -2; #ifdef CONFIG_BLK_DEV_INITRD /* * Make sure that the initrd is within a valid area of * memory. */ if (initrd_start) { unsigned long phys_initrd_start, phys_initrd_end; unsigned int i; phys_initrd_start = __pa(initrd_start); phys_initrd_end = __pa(initrd_end); for (i = 0; i < mi->nr_banks; i++) { unsigned long bank_end; bank_end = mi->bank[i].start + mi->bank[i].size; if (mi->bank[i].start <= phys_initrd_start && phys_initrd_end <= bank_end) initrd_node = mi->bank[i].node; } } if (initrd_node == -1) { printk(KERN_ERR "initrd (0x%08lx - 0x%08lx) extends beyond " "physical memory - disabling initrd\n", initrd_start, initrd_end); initrd_start = initrd_end = 0; } #endif return initrd_node; } /* * Reserve the various regions of node 0 */ static inline void reserve_node_zero(unsigned int bootmap_pfn, unsigned int bootmap_pages) { /* * Register the kernel text and data with bootmem. * Note that this can only be in node 0. */ reserve_bootmem_node(0, __pa(&_stext), &_end - &_stext); #ifdef CONFIG_CPU_32 /* * Reserve the page tables. These are already in use, * and can only be in node 0. */ reserve_bootmem_node(0, __pa(swapper_pg_dir), PTRS_PER_PGD * sizeof(void *)); #else /* * Stop this memory from being grabbed - its special DMA * memory that is required for the screen. */ reserve_bootmem_node(0, 0x02000000, 0x00080000); #endif /* * And don't forget to reserve the allocator bitmap, * which will be freed later. */ reserve_bootmem_node(0, bootmap_pfn << PAGE_SHIFT, bootmap_pages << PAGE_SHIFT); } /* * Register all available RAM in this node with the bootmem allocator. */ static inline void free_bootmem_node_bank(int node, struct meminfo *mi) { int bank; for (bank = 0; bank < mi->nr_banks; bank++) if (mi->bank[bank].node == node) free_bootmem_node(node, mi->bank[bank].start, mi->bank[bank].size); } /* * Initialise the bootmem allocator for all nodes. This is called * early during the architecture specific initialisation. */ void __init bootmem_init(struct meminfo *mi) { struct node_info node_info[NR_NODES], *np = node_info; unsigned int bootmap_pages, bootmap_pfn, map_pg; int node, initrd_node; bootmap_pages = find_memend_and_nodes(mi, np); bootmap_pfn = find_bootmap_pfn(0, mi, bootmap_pages); initrd_node = check_initrd(mi); map_pg = bootmap_pfn; for (node = 0; node < numnodes; node++, np++) { /* * If there are no pages in this node, ignore it. * Note that node 0 must always have some pages. */ if (np->end == 0) { if (node == 0) BUG(); continue; } /* * Initialise the bootmem allocator. */ init_bootmem_node(node, map_pg, np->start, np->end); free_bootmem_node_bank(node, mi); map_pg += np->bootmap_pages; /* * If this is node 0, we need to reserve some areas ASAP - * we may use bootmem on node 0 to setup the other nodes. */ if (node == 0) reserve_node_zero(bootmap_pfn, bootmap_pages); } #ifdef CONFIG_BLK_DEV_INITRD if (initrd_node >= 0) reserve_bootmem_node(initrd_node, __pa(initrd_start), initrd_end - initrd_start); #endif if (map_pg != bootmap_pfn + bootmap_pages) BUG(); } /* * paging_init() sets up the page tables, initialises the zone memory * maps, and sets up the zero page, bad page and bad page tables. */ void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc) { void *zero_page, *bad_page, *bad_table; int node; memcpy(&meminfo, mi, sizeof(meminfo)); /* * allocate what we need for the bad pages. * note that we count on this going ok. */ zero_page = alloc_bootmem_low_pages(PAGE_SIZE); bad_page = alloc_bootmem_low_pages(PAGE_SIZE); bad_table = alloc_bootmem_low_pages(TABLE_SIZE); /* * initialise the page tables. */ memtable_init(mi); if (mdesc->map_io) mdesc->map_io(); flush_tlb_all(); /* * initialise the zones within each node */ for (node = 0; node < numnodes; node++) { unsigned long zone_size[MAX_NR_ZONES]; unsigned long zhole_size[MAX_NR_ZONES]; struct bootmem_data *bdata; pg_data_t *pgdat; int i; /* * Initialise the zone size information. */ for (i = 0; i < MAX_NR_ZONES; i++) { zone_size[i] = 0; zhole_size[i] = 0; } pgdat = NODE_DATA(node); bdata = pgdat->bdata; /* * The size of this node has already been determined. * If we need to do anything fancy with the allocation * of this memory to the zones, now is the time to do * it. */ zone_size[0] = bdata->node_low_pfn - (bdata->node_boot_start >> PAGE_SHIFT); /* * For each bank in this node, calculate the size of the * holes. holes = node_size - sum(bank_sizes_in_node) */ zhole_size[0] = zone_size[0]; for (i = 0; i < mi->nr_banks; i++) { if (mi->bank[i].node != node) continue; zhole_size[0] -= mi->bank[i].size >> PAGE_SHIFT; } free_area_init_node(node, pgdat, 0, zone_size, bdata->node_boot_start, zhole_size); } /* * finish off the bad pages once * the mem_map is initialised */ memzero(zero_page, PAGE_SIZE); memzero(bad_page, PAGE_SIZE); empty_zero_page = virt_to_page(zero_page); empty_bad_page = virt_to_page(bad_page); empty_bad_pte_table = ((pte_t *)bad_table) + TABLE_OFFSET; } /* * mem_init() marks the free areas in the mem_map and tells us how much * memory is free. This is done after various parts of the system have * claimed their memory after the kernel image. */ void __init mem_init(void) { unsigned int codepages, datapages, initpages; int i, node; codepages = &_etext - &_text; datapages = &_end - &_etext; initpages = &__init_end - &__init_begin; high_memory = (void *)__va(meminfo.end); max_mapnr = virt_to_page(high_memory) - mem_map; /* * We may have non-contiguous memory. */ if (meminfo.nr_banks != 1) create_memmap_holes(&meminfo); /* this will put all unused low memory onto the freelists */ for (node = 0; node < numnodes; node++) totalram_pages += free_all_bootmem_node(node); /* * Since our memory may not be contiguous, calculate the * real number of pages we have in this system */ printk(KERN_INFO "Memory:"); num_physpages = 0; for (i = 0; i < meminfo.nr_banks; i++) { num_physpages += meminfo.bank[i].size >> PAGE_SHIFT; printk(" %ldMB", meminfo.bank[i].size >> 20); } printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT)); printk(KERN_NOTICE "Memory: %luKB available (%dK code, " "%dK data, %dK init)\n", (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), codepages >> 10, datapages >> 10, initpages >> 10); if (PAGE_SIZE >= 16384 && num_physpages <= 128) { extern int sysctl_overcommit_memory; /* * On a machine this small we won't get * anywhere without overcommit, so turn * it on by default. */ sysctl_overcommit_memory = 1; } } static inline void free_area(unsigned long addr, unsigned long end, char *s) { unsigned int size = (end - addr) >> 10; for (; addr < end; addr += PAGE_SIZE) { struct page *page = virt_to_page(addr); ClearPageReserved(page); set_page_count(page, 1); free_page(addr); totalram_pages++; } if (size) printk("Freeing %s memory: %dK\n", s, size); } void free_initmem(void) { free_area((unsigned long)(&__init_begin), (unsigned long)(&__init_end), "init"); } #ifdef CONFIG_BLK_DEV_INITRD static int keep_initrd; void free_initrd_mem(unsigned long start, unsigned long end) { if (!keep_initrd) free_area(start, end, "initrd"); } static int __init keepinitrd_setup(char *__unused) { keep_initrd = 1; return 1; } __setup("keepinitrd", keepinitrd_setup); #endif void si_meminfo(struct sysinfo *val) { val->totalram = totalram_pages; val->sharedram = 0; val->freeram = nr_free_pages(); val->bufferram = atomic_read(&buffermem_pages); val->totalhigh = 0; val->freehigh = 0; val->mem_unit = PAGE_SIZE; }