/* * Handle the memory map. * The functions here do the job until bootmem takes over. * $Id: e820.c,v 1.4 2002/09/19 19:25:32 ak Exp $ * * Getting sanitize_e820_map() in sync with i386 version by applying change: * - Provisions for empty E820 memory regions (reported by certain BIOSes). * Alex Achenbach , December 2002. * Venkatesh Pallipadi * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * PFN of last memory page. */ unsigned long end_pfn; EXPORT_SYMBOL(end_pfn); /* * end_pfn only includes RAM, while end_pfn_map includes all e820 entries. * The direct mapping extends to end_pfn_map, so that we can directly access * apertures, ACPI and other tables without having to play with fixmaps. */ unsigned long end_pfn_map; /* * Last pfn which the user wants to use. */ unsigned long end_user_pfn = MAXMEM>>PAGE_SHIFT; extern struct resource code_resource, data_resource; /* Check for some hardcoded bad areas that early boot is not allowed to touch */ static inline int bad_addr(unsigned long *addrp, unsigned long size) { unsigned long addr = *addrp, last = addr + size; /* various gunk below that needed for SMP startup */ if (addr < 0x8000) { *addrp = 0x8000; return 1; } /* direct mapping tables of the kernel */ if (last >= table_start<= INITRD_START && addr < INITRD_START+INITRD_SIZE) { *addrp = INITRD_START + INITRD_SIZE; return 1; } #endif /* kernel code + 640k memory hole (later should not be needed, but be paranoid for now) */ if (last >= 640*1024 && addr < __pa_symbol(&_end)) { *addrp = __pa_symbol(&_end); return 1; } /* XXX ramdisk image here? */ return 0; } /* * This function checks if any part of the range is mapped * with type. */ int __meminit e820_any_mapped(unsigned long start, unsigned long end, unsigned type) { int i; for (i = 0; i < e820.nr_map; i++) { struct e820entry *ei = &e820.map[i]; if (type && ei->type != type) continue; if (ei->addr >= end || ei->addr + ei->size <= start) continue; return 1; } return 0; } /* * This function checks if the entire range is mapped with type. * * Note: this function only works correct if the e820 table is sorted and * not-overlapping, which is the case */ int __init e820_all_mapped(unsigned long start, unsigned long end, unsigned type) { int i; for (i = 0; i < e820.nr_map; i++) { struct e820entry *ei = &e820.map[i]; if (type && ei->type != type) continue; /* is the region (part) in overlap with the current region ?*/ if (ei->addr >= end || ei->addr + ei->size <= start) continue; /* if the region is at the beginning of we move * start to the end of the region since it's ok until there */ if (ei->addr <= start) start = ei->addr + ei->size; /* if start is now at or beyond end, we're done, full coverage */ if (start >= end) return 1; /* we're done */ } return 0; } /* * Find a free area in a specific range. */ unsigned long __init find_e820_area(unsigned long start, unsigned long end, unsigned size) { int i; for (i = 0; i < e820.nr_map; i++) { struct e820entry *ei = &e820.map[i]; unsigned long addr = ei->addr, last; if (ei->type != E820_RAM) continue; if (addr < start) addr = start; if (addr > ei->addr + ei->size) continue; while (bad_addr(&addr, size) && addr+size < ei->addr + ei->size) ; last = addr + size; if (last > ei->addr + ei->size) continue; if (last > end) continue; return addr; } return -1UL; } /* * Free bootmem based on the e820 table for a node. */ void __init e820_bootmem_free(pg_data_t *pgdat, unsigned long start,unsigned long end) { int i; for (i = 0; i < e820.nr_map; i++) { struct e820entry *ei = &e820.map[i]; unsigned long last, addr; if (ei->type != E820_RAM || ei->addr+ei->size <= start || ei->addr >= end) continue; addr = round_up(ei->addr, PAGE_SIZE); if (addr < start) addr = start; last = round_down(ei->addr + ei->size, PAGE_SIZE); if (last >= end) last = end; if (last > addr && last-addr >= PAGE_SIZE) free_bootmem_node(pgdat, addr, last-addr); } } /* * Find the highest page frame number we have available */ unsigned long __init e820_end_of_ram(void) { int i; unsigned long end_pfn = 0; for (i = 0; i < e820.nr_map; i++) { struct e820entry *ei = &e820.map[i]; unsigned long start, end; start = round_up(ei->addr, PAGE_SIZE); end = round_down(ei->addr + ei->size, PAGE_SIZE); if (start >= end) continue; if (ei->type == E820_RAM) { if (end > end_pfn<>PAGE_SHIFT; } else { if (end > end_pfn_map<>PAGE_SHIFT; } } if (end_pfn > end_pfn_map) end_pfn_map = end_pfn; if (end_pfn_map > MAXMEM>>PAGE_SHIFT) end_pfn_map = MAXMEM>>PAGE_SHIFT; if (end_pfn > end_user_pfn) end_pfn = end_user_pfn; if (end_pfn > end_pfn_map) end_pfn = end_pfn_map; return end_pfn; } /* * Compute how much memory is missing in a range. * Unlike the other functions in this file the arguments are in page numbers. */ unsigned long __init e820_hole_size(unsigned long start_pfn, unsigned long end_pfn) { unsigned long ram = 0; unsigned long start = start_pfn << PAGE_SHIFT; unsigned long end = end_pfn << PAGE_SHIFT; int i; for (i = 0; i < e820.nr_map; i++) { struct e820entry *ei = &e820.map[i]; unsigned long last, addr; if (ei->type != E820_RAM || ei->addr+ei->size <= start || ei->addr >= end) continue; addr = round_up(ei->addr, PAGE_SIZE); if (addr < start) addr = start; last = round_down(ei->addr + ei->size, PAGE_SIZE); if (last >= end) last = end; if (last > addr) ram += last - addr; } return ((end - start) - ram) >> PAGE_SHIFT; } /* * Mark e820 reserved areas as busy for the resource manager. */ void __init e820_reserve_resources(void) { int i; for (i = 0; i < e820.nr_map; i++) { struct resource *res; res = alloc_bootmem_low(sizeof(struct resource)); switch (e820.map[i].type) { case E820_RAM: res->name = "System RAM"; break; case E820_ACPI: res->name = "ACPI Tables"; break; case E820_NVS: res->name = "ACPI Non-volatile Storage"; break; default: res->name = "reserved"; } res->start = e820.map[i].addr; res->end = res->start + e820.map[i].size - 1; res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; request_resource(&iomem_resource, res); if (e820.map[i].type == E820_RAM) { /* * We don't know which RAM region contains kernel data, * so we try it repeatedly and let the resource manager * test it. */ request_resource(res, &code_resource); request_resource(res, &data_resource); #ifdef CONFIG_KEXEC request_resource(res, &crashk_res); #endif } } } /* * Add a memory region to the kernel e820 map. */ void __init add_memory_region(unsigned long start, unsigned long size, int type) { int x = e820.nr_map; if (x == E820MAX) { printk(KERN_ERR "Ooops! Too many entries in the memory map!\n"); return; } e820.map[x].addr = start; e820.map[x].size = size; e820.map[x].type = type; e820.nr_map++; } void __init e820_print_map(char *who) { int i; for (i = 0; i < e820.nr_map; i++) { printk(" %s: %016Lx - %016Lx ", who, (unsigned long long) e820.map[i].addr, (unsigned long long) (e820.map[i].addr + e820.map[i].size)); switch (e820.map[i].type) { case E820_RAM: printk("(usable)\n"); break; case E820_RESERVED: printk("(reserved)\n"); break; case E820_ACPI: printk("(ACPI data)\n"); break; case E820_NVS: printk("(ACPI NVS)\n"); break; default: printk("type %u\n", e820.map[i].type); break; } } } /* * Sanitize the BIOS e820 map. * * Some e820 responses include overlapping entries. The following * replaces the original e820 map with a new one, removing overlaps. * */ static int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map) { struct change_member { struct e820entry *pbios; /* pointer to original bios entry */ unsigned long long addr; /* address for this change point */ }; static struct change_member change_point_list[2*E820MAX] __initdata; static struct change_member *change_point[2*E820MAX] __initdata; static struct e820entry *overlap_list[E820MAX] __initdata; static struct e820entry new_bios[E820MAX] __initdata; struct change_member *change_tmp; unsigned long current_type, last_type; unsigned long long last_addr; int chgidx, still_changing; int overlap_entries; int new_bios_entry; int old_nr, new_nr, chg_nr; int i; /* Visually we're performing the following (1,2,3,4 = memory types)... Sample memory map (w/overlaps): ____22__________________ ______________________4_ ____1111________________ _44_____________________ 11111111________________ ____________________33__ ___________44___________ __________33333_________ ______________22________ ___________________2222_ _________111111111______ _____________________11_ _________________4______ Sanitized equivalent (no overlap): 1_______________________ _44_____________________ ___1____________________ ____22__________________ ______11________________ _________1______________ __________3_____________ ___________44___________ _____________33_________ _______________2________ ________________1_______ _________________4______ ___________________2____ ____________________33__ ______________________4_ */ /* if there's only one memory region, don't bother */ if (*pnr_map < 2) return -1; old_nr = *pnr_map; /* bail out if we find any unreasonable addresses in bios map */ for (i=0; iaddr = biosmap[i].addr; change_point[chgidx++]->pbios = &biosmap[i]; change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size; change_point[chgidx++]->pbios = &biosmap[i]; } } chg_nr = chgidx; /* sort change-point list by memory addresses (low -> high) */ still_changing = 1; while (still_changing) { still_changing = 0; for (i=1; i < chg_nr; i++) { /* if > , swap */ /* or, if current= & last=, swap */ if ((change_point[i]->addr < change_point[i-1]->addr) || ((change_point[i]->addr == change_point[i-1]->addr) && (change_point[i]->addr == change_point[i]->pbios->addr) && (change_point[i-1]->addr != change_point[i-1]->pbios->addr)) ) { change_tmp = change_point[i]; change_point[i] = change_point[i-1]; change_point[i-1] = change_tmp; still_changing=1; } } } /* create a new bios memory map, removing overlaps */ overlap_entries=0; /* number of entries in the overlap table */ new_bios_entry=0; /* index for creating new bios map entries */ last_type = 0; /* start with undefined memory type */ last_addr = 0; /* start with 0 as last starting address */ /* loop through change-points, determining affect on the new bios map */ for (chgidx=0; chgidx < chg_nr; chgidx++) { /* keep track of all overlapping bios entries */ if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr) { /* add map entry to overlap list (> 1 entry implies an overlap) */ overlap_list[overlap_entries++]=change_point[chgidx]->pbios; } else { /* remove entry from list (order independent, so swap with last) */ for (i=0; ipbios) overlap_list[i] = overlap_list[overlap_entries-1]; } overlap_entries--; } /* if there are overlapping entries, decide which "type" to use */ /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */ current_type = 0; for (i=0; itype > current_type) current_type = overlap_list[i]->type; /* continue building up new bios map based on this information */ if (current_type != last_type) { if (last_type != 0) { new_bios[new_bios_entry].size = change_point[chgidx]->addr - last_addr; /* move forward only if the new size was non-zero */ if (new_bios[new_bios_entry].size != 0) if (++new_bios_entry >= E820MAX) break; /* no more space left for new bios entries */ } if (current_type != 0) { new_bios[new_bios_entry].addr = change_point[chgidx]->addr; new_bios[new_bios_entry].type = current_type; last_addr=change_point[chgidx]->addr; } last_type = current_type; } } new_nr = new_bios_entry; /* retain count for new bios entries */ /* copy new bios mapping into original location */ memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry)); *pnr_map = new_nr; return 0; } /* * Copy the BIOS e820 map into a safe place. * * Sanity-check it while we're at it.. * * If we're lucky and live on a modern system, the setup code * will have given us a memory map that we can use to properly * set up memory. If we aren't, we'll fake a memory map. * * We check to see that the memory map contains at least 2 elements * before we'll use it, because the detection code in setup.S may * not be perfect and most every PC known to man has two memory * regions: one from 0 to 640k, and one from 1mb up. (The IBM * thinkpad 560x, for example, does not cooperate with the memory * detection code.) */ static int __init copy_e820_map(struct e820entry * biosmap, int nr_map) { /* Only one memory region (or negative)? Ignore it */ if (nr_map < 2) return -1; do { unsigned long start = biosmap->addr; unsigned long size = biosmap->size; unsigned long end = start + size; unsigned long type = biosmap->type; /* Overflow in 64 bits? Ignore the memory map. */ if (start > end) return -1; /* * Some BIOSes claim RAM in the 640k - 1M region. * Not right. Fix it up. * * This should be removed on Hammer which is supposed to not * have non e820 covered ISA mappings there, but I had some strange * problems so it stays for now. -AK */ if (type == E820_RAM) { if (start < 0x100000ULL && end > 0xA0000ULL) { if (start < 0xA0000ULL) add_memory_region(start, 0xA0000ULL-start, type); if (end <= 0x100000ULL) continue; start = 0x100000ULL; size = end - start; } } add_memory_region(start, size, type); } while (biosmap++,--nr_map); return 0; } void __init setup_memory_region(void) { char *who = "BIOS-e820"; /* * Try to copy the BIOS-supplied E820-map. * * Otherwise fake a memory map; one section from 0k->640k, * the next section from 1mb->appropriate_mem_k */ sanitize_e820_map(E820_MAP, &E820_MAP_NR); if (copy_e820_map(E820_MAP, E820_MAP_NR) < 0) { unsigned long mem_size; /* compare results from other methods and take the greater */ if (ALT_MEM_K < EXT_MEM_K) { mem_size = EXT_MEM_K; who = "BIOS-88"; } else { mem_size = ALT_MEM_K; who = "BIOS-e801"; } e820.nr_map = 0; add_memory_region(0, LOWMEMSIZE(), E820_RAM); add_memory_region(HIGH_MEMORY, mem_size << 10, E820_RAM); } printk(KERN_INFO "BIOS-provided physical RAM map:\n"); e820_print_map(who); } void __init parse_memopt(char *p, char **from) { end_user_pfn = memparse(p, from); end_user_pfn >>= PAGE_SHIFT; } void __init parse_memmapopt(char *p, char **from) { unsigned long long start_at, mem_size; mem_size = memparse(p, from); p = *from; if (*p == '@') { start_at = memparse(p+1, from); add_memory_region(start_at, mem_size, E820_RAM); } else if (*p == '#') { start_at = memparse(p+1, from); add_memory_region(start_at, mem_size, E820_ACPI); } else if (*p == '$') { start_at = memparse(p+1, from); add_memory_region(start_at, mem_size, E820_RESERVED); } else { end_user_pfn = (mem_size >> PAGE_SHIFT); } p = *from; } unsigned long pci_mem_start = 0xaeedbabe; /* * Search for the biggest gap in the low 32 bits of the e820 * memory space. We pass this space to PCI to assign MMIO resources * for hotplug or unconfigured devices in. * Hopefully the BIOS let enough space left. */ __init void e820_setup_gap(void) { unsigned long gapstart, gapsize, round; unsigned long last; int i; int found = 0; last = 0x100000000ull; gapstart = 0x10000000; gapsize = 0x400000; i = e820.nr_map; while (--i >= 0) { unsigned long long start = e820.map[i].addr; unsigned long long end = start + e820.map[i].size; /* * Since "last" is at most 4GB, we know we'll * fit in 32 bits if this condition is true */ if (last > end) { unsigned long gap = last - end; if (gap > gapsize) { gapsize = gap; gapstart = end; found = 1; } } if (start < last) last = start; } if (!found) { gapstart = (end_pfn << PAGE_SHIFT) + 1024*1024; printk(KERN_ERR "PCI: Warning: Cannot find a gap in the 32bit address range\n" KERN_ERR "PCI: Unassigned devices with 32bit resource registers may break!\n"); } /* * See how much we want to round up: start off with * rounding to the next 1MB area. */ round = 0x100000; while ((gapsize >> 4) > round) round += round; /* Fun with two's complement */ pci_mem_start = (gapstart + round) & -round; printk(KERN_INFO "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n", pci_mem_start, gapstart, gapsize); }