/* * linux/arch/arm/mm/init.c * * Copyright (C) 1995-2005 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 "mm.h" DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; extern void _stext, _text, _etext, __data_start, _end, __init_begin, __init_end; extern unsigned long phys_initrd_start; extern unsigned long phys_initrd_size; /* * The sole use of this is to pass memory configuration * data from paging_init to mem_init. */ static struct meminfo meminfo __initdata = { 0, }; /* * empty_zero_page is a special page that is used for * zero-initialized data and COW. */ struct page *empty_zero_page; /* * The pmd table for the upper-most set of pages. */ pmd_t *top_pmd; void show_mem(void) { int free = 0, total = 0, reserved = 0; int shared = 0, cached = 0, slab = 0, node; printk("Mem-info:\n"); show_free_areas(); printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); for_each_online_node(node) { struct page *page, *end; page = NODE_MEM_MAP(node); end = page + NODE_DATA(node)->node_spanned_pages; do { total++; if (PageReserved(page)) reserved++; else if (PageSwapCache(page)) cached++; else if (PageSlab(page)) slab++; else if (!page_count(page)) free++; else shared += page_count(page) - 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 slab pages\n", slab); printk("%d pages shared\n", shared); printk("%d pages swap cached\n", cached); } #define for_each_nodebank(iter,mi,no) \ for (iter = 0; iter < mi->nr_banks; iter++) \ if (mi->bank[iter].node == no) /* * 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 = PAGE_ALIGN(__pa(&_end)) >> PAGE_SHIFT; bootmap_pfn = 0; for_each_nodebank(bank, mi, node) { unsigned int start, end; start = mi->bank[bank].start >> PAGE_SHIFT; end = (mi->bank[bank].size + mi->bank[bank].start) >> PAGE_SHIFT; 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; } static int __init check_initrd(struct meminfo *mi) { int initrd_node = -2; #ifdef CONFIG_BLK_DEV_INITRD unsigned long end = phys_initrd_start + phys_initrd_size; /* * Make sure that the initrd is within a valid area of * memory. */ if (phys_initrd_size) { unsigned int i; initrd_node = -1; 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 && 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", phys_initrd_start, end); phys_initrd_start = phys_initrd_size = 0; } #endif return initrd_node; } /* * Reserve the various regions of node 0 */ static __init void reserve_node_zero(pg_data_t *pgdat) { unsigned long res_size = 0; /* * Register the kernel text and data with bootmem. * Note that this can only be in node 0. */ #ifdef CONFIG_XIP_KERNEL reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start); #else reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext); #endif /* * Reserve the page tables. These are already in use, * and can only be in node 0. */ reserve_bootmem_node(pgdat, __pa(swapper_pg_dir), PTRS_PER_PGD * sizeof(pgd_t)); /* * Hmm... This should go elsewhere, but we really really need to * stop things allocating the low memory; ideally we need a better * implementation of GFP_DMA which does not assume that DMA-able * memory starts at zero. */ if (machine_is_integrator() || machine_is_cintegrator()) res_size = __pa(swapper_pg_dir) - PHYS_OFFSET; /* * These should likewise go elsewhere. They pre-reserve the * screen memory region at the start of main system memory. */ if (machine_is_edb7211()) res_size = 0x00020000; if (machine_is_p720t()) res_size = 0x00014000; #ifdef CONFIG_SA1111 /* * Because of the SA1111 DMA bug, we want to preserve our * precious DMA-able memory... */ res_size = __pa(swapper_pg_dir) - PHYS_OFFSET; #endif if (res_size) reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size); } static inline void prepare_page_table(struct meminfo *mi) { unsigned long addr; /* * Clear out all the mappings below the kernel image. */ for (addr = 0; addr < MODULE_START; addr += PGDIR_SIZE) pmd_clear(pmd_off_k(addr)); #ifdef CONFIG_XIP_KERNEL /* The XIP kernel is mapped in the module area -- skip over it */ addr = ((unsigned long)&_etext + PGDIR_SIZE - 1) & PGDIR_MASK; #endif for ( ; addr < PAGE_OFFSET; addr += PGDIR_SIZE) pmd_clear(pmd_off_k(addr)); /* * Clear out all the kernel space mappings, except for the first * memory bank, up to the end of the vmalloc region. */ for (addr = __phys_to_virt(mi->bank[0].start + mi->bank[0].size); addr < VMALLOC_END; addr += PGDIR_SIZE) pmd_clear(pmd_off_k(addr)); } static inline void map_memory_bank(struct membank *bank) { struct map_desc map; map.pfn = __phys_to_pfn(bank->start); map.virtual = __phys_to_virt(bank->start); map.length = bank->size; map.type = MT_MEMORY; create_mapping(&map); } static unsigned long __init bootmem_init_node(int node, int initrd_node, struct meminfo *mi) { unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES]; unsigned long start_pfn, end_pfn, boot_pfn; unsigned int boot_pages; pg_data_t *pgdat; int i; start_pfn = -1UL; end_pfn = 0; /* * Calculate the pfn range, and map the memory banks for this node. */ for_each_nodebank(i, mi, node) { struct membank *bank = &mi->bank[i]; unsigned long start, end; start = bank->start >> PAGE_SHIFT; end = (bank->start + bank->size) >> PAGE_SHIFT; if (start_pfn > start) start_pfn = start; if (end_pfn < end) end_pfn = end; map_memory_bank(bank); } /* * If there is no memory in this node, ignore it. */ if (end_pfn == 0) return end_pfn; /* * Allocate the bootmem bitmap page. */ boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn); boot_pfn = find_bootmap_pfn(node, mi, boot_pages); /* * Initialise the bootmem allocator for this node, handing the * memory banks over to bootmem. */ node_set_online(node); pgdat = NODE_DATA(node); init_bootmem_node(pgdat, boot_pfn, start_pfn, end_pfn); for_each_nodebank(i, mi, node) free_bootmem_node(pgdat, mi->bank[i].start, mi->bank[i].size); /* * Reserve the bootmem bitmap for this node. */ reserve_bootmem_node(pgdat, boot_pfn << PAGE_SHIFT, boot_pages << PAGE_SHIFT); #ifdef CONFIG_BLK_DEV_INITRD /* * If the initrd is in this node, reserve its memory. */ if (node == initrd_node) { reserve_bootmem_node(pgdat, phys_initrd_start, phys_initrd_size); initrd_start = __phys_to_virt(phys_initrd_start); initrd_end = initrd_start + phys_initrd_size; } #endif /* * Finally, reserve any node zero regions. */ if (node == 0) reserve_node_zero(pgdat); /* * initialise the zones within this node. */ memset(zone_size, 0, sizeof(zone_size)); memset(zhole_size, 0, sizeof(zhole_size)); /* * 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] = end_pfn - start_pfn; /* * 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_each_nodebank(i, mi, node) zhole_size[0] -= mi->bank[i].size >> PAGE_SHIFT; /* * Adjust the sizes according to any special requirements for * this machine type. */ arch_adjust_zones(node, zone_size, zhole_size); free_area_init_node(node, pgdat, zone_size, start_pfn, zhole_size); return end_pfn; } static void __init bootmem_init(struct meminfo *mi) { unsigned long memend_pfn = 0; int node, initrd_node, i; /* * Invalidate the node number for empty or invalid memory banks */ for (i = 0; i < mi->nr_banks; i++) if (mi->bank[i].size == 0 || mi->bank[i].node >= MAX_NUMNODES) mi->bank[i].node = -1; memcpy(&meminfo, mi, sizeof(meminfo)); prepare_page_table(mi); /* * Locate which node contains the ramdisk image, if any. */ initrd_node = check_initrd(mi); /* * Run through each node initialising the bootmem allocator. */ for_each_node(node) { unsigned long end_pfn; end_pfn = bootmem_init_node(node, initrd_node, mi); /* * Remember the highest memory PFN. */ if (end_pfn > memend_pfn) memend_pfn = end_pfn; } high_memory = __va(memend_pfn << PAGE_SHIFT); /* * This doesn't seem to be used by the Linux memory manager any * more, but is used by ll_rw_block. If we can get rid of it, we * also get rid of some of the stuff above as well. * * Note: max_low_pfn and max_pfn reflect the number of _pages_ in * the system, not the maximum PFN. */ max_pfn = max_low_pfn = memend_pfn - PHYS_PFN_OFFSET; } /* * Set up device the mappings. Since we clear out the page tables for all * mappings above VMALLOC_END, we will remove any debug device mappings. * This means you have to be careful how you debug this function, or any * called function. This means you can't use any function or debugging * method which may touch any device, otherwise the kernel _will_ crash. */ static void __init devicemaps_init(struct machine_desc *mdesc) { struct map_desc map; unsigned long addr; void *vectors; /* * Allocate the vector page early. */ vectors = alloc_bootmem_low_pages(PAGE_SIZE); BUG_ON(!vectors); for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE) pmd_clear(pmd_off_k(addr)); /* * Map the kernel if it is XIP. * It is always first in the modulearea. */ #ifdef CONFIG_XIP_KERNEL map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK); map.virtual = MODULE_START; map.length = ((unsigned long)&_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK; map.type = MT_ROM; create_mapping(&map); #endif /* * Map the cache flushing regions. */ #ifdef FLUSH_BASE map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS); map.virtual = FLUSH_BASE; map.length = SZ_1M; map.type = MT_CACHECLEAN; create_mapping(&map); #endif #ifdef FLUSH_BASE_MINICACHE map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M); map.virtual = FLUSH_BASE_MINICACHE; map.length = SZ_1M; map.type = MT_MINICLEAN; create_mapping(&map); #endif /* * Create a mapping for the machine vectors at the high-vectors * location (0xffff0000). If we aren't using high-vectors, also * create a mapping at the low-vectors virtual address. */ map.pfn = __phys_to_pfn(virt_to_phys(vectors)); map.virtual = 0xffff0000; map.length = PAGE_SIZE; map.type = MT_HIGH_VECTORS; create_mapping(&map); if (!vectors_high()) { map.virtual = 0; map.type = MT_LOW_VECTORS; create_mapping(&map); } /* * Ask the machine support to map in the statically mapped devices. */ if (mdesc->map_io) mdesc->map_io(); /* * Finally flush the caches and tlb to ensure that we're in a * consistent state wrt the writebuffer. This also ensures that * any write-allocated cache lines in the vector page are written * back. After this point, we can start to touch devices again. */ local_flush_tlb_all(); flush_cache_all(); } /* * 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; build_mem_type_table(); bootmem_init(mi); devicemaps_init(mdesc); top_pmd = pmd_off_k(0xffff0000); /* * allocate the zero page. Note that we count on this going ok. */ zero_page = alloc_bootmem_low_pages(PAGE_SIZE); memzero(zero_page, PAGE_SIZE); empty_zero_page = virt_to_page(zero_page); flush_dcache_page(empty_zero_page); } 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); init_page_count(page); free_page(addr); totalram_pages++; } if (size && s) printk(KERN_INFO "Freeing %s memory: %dK\n", s, size); } static inline void free_memmap(int node, unsigned long start_pfn, unsigned long end_pfn) { struct page *start_pg, *end_pg; unsigned long pg, pgend; /* * Convert start_pfn/end_pfn to a struct page pointer. */ start_pg = pfn_to_page(start_pfn); end_pg = pfn_to_page(end_pfn); /* * Convert to physical addresses, and * round start upwards and end downwards. */ pg = PAGE_ALIGN(__pa(start_pg)); pgend = __pa(end_pg) & PAGE_MASK; /* * If there are free pages between these, * free the section of the memmap array. */ if (pg < pgend) free_bootmem_node(NODE_DATA(node), pg, pgend - pg); } /* * The mem_map array can get very big. Free the unused area of the memory map. */ static void __init free_unused_memmap_node(int node, struct meminfo *mi) { unsigned long bank_start, prev_bank_end = 0; unsigned int i; /* * [FIXME] This relies on each bank being in address order. This * may not be the case, especially if the user has provided the * information on the command line. */ for_each_nodebank(i, mi, node) { bank_start = mi->bank[i].start >> PAGE_SHIFT; if (bank_start < prev_bank_end) { printk(KERN_ERR "MEM: unordered memory banks. " "Not freeing memmap.\n"); break; } /* * If we had a previous bank, and there is a space * between the current bank and the previous, free it. */ if (prev_bank_end && prev_bank_end != bank_start) free_memmap(node, prev_bank_end, bank_start); prev_bank_end = (mi->bank[i].start + mi->bank[i].size) >> PAGE_SHIFT; } } /* * 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 - &__data_start; initpages = &__init_end - &__init_begin; #ifndef CONFIG_DISCONTIGMEM max_mapnr = virt_to_page(high_memory) - mem_map; #endif /* this will put all unused low memory onto the freelists */ for_each_online_node(node) { pg_data_t *pgdat = NODE_DATA(node); free_unused_memmap_node(node, &meminfo); if (pgdat->node_spanned_pages != 0) totalram_pages += free_all_bootmem_node(pgdat); } #ifdef CONFIG_SA1111 /* now that our DMA memory is actually so designated, we can free it */ free_area(PAGE_OFFSET, (unsigned long)swapper_pg_dir, NULL); #endif /* * 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 = OVERCOMMIT_ALWAYS; } } void free_initmem(void) { if (!machine_is_integrator() && !machine_is_cintegrator()) { 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