/* * Handle the memory map. * The functions here do the job until bootmem takes over. * * 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 struct e820map e820; /* For PCI or other memory-mapped resources */ unsigned long pci_mem_start = 0xaeedbabe; #ifdef CONFIG_PCI EXPORT_SYMBOL(pci_mem_start); #endif /* * This function checks if any part of the range is mapped * with type. */ int e820_any_mapped(u64 start, u64 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; } EXPORT_SYMBOL_GPL(e820_any_mapped); /* * 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(u64 start, u64 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; } return 0; } /* * Add a memory region to the kernel e820 map. */ void __init add_memory_region(u64 start, u64 size, int type) { int x = e820.nr_map; if (x == ARRAY_SIZE(e820.map)) { 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(KERN_INFO " %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(KERN_CONT "(usable)\n"); break; case E820_RESERVED: printk(KERN_CONT "(reserved)\n"); break; case E820_ACPI: printk(KERN_CONT "(ACPI data)\n"); break; case E820_NVS: printk(KERN_CONT "(ACPI NVS)\n"); break; default: printk(KERN_CONT "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. * */ int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map, int *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*E820_X_MAX] __initdata; static struct change_member *change_point[2*E820_X_MAX] __initdata; static struct e820entry *overlap_list[E820_X_MAX] __initdata; static struct e820entry new_bios[E820_X_MAX] __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; BUG_ON(old_nr > max_nr_map); /* bail out if we find any unreasonable addresses in bios map */ for (i = 0; i < old_nr; i++) if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr) return -1; /* create pointers for initial change-point information (for sorting) */ for (i = 0; i < 2 * old_nr; i++) change_point[i] = &change_point_list[i]; /* record all known change-points (starting and ending addresses), omitting those that are for empty memory regions */ chgidx = 0; for (i = 0; i < old_nr; i++) { if (biosmap[i].size != 0) { change_point[chgidx]->addr = 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++) { unsigned long long curaddr, lastaddr; unsigned long long curpbaddr, lastpbaddr; curaddr = change_point[i]->addr; lastaddr = change_point[i - 1]->addr; curpbaddr = change_point[i]->pbios->addr; lastpbaddr = change_point[i - 1]->pbios->addr; /* * swap entries, when: * * curaddr > lastaddr or * curaddr == lastaddr and curaddr == curpbaddr and * lastaddr != lastpbaddr */ if (curaddr < lastaddr || (curaddr == lastaddr && curaddr == curpbaddr && lastaddr != lastpbaddr)) { 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; i < overlap_entries; i++) { if (overlap_list[i] == change_point[chgidx]->pbios) 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; i < overlap_entries; i++) if (overlap_list[i]->type > 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) /* * no more space left for new * bios entries ? */ if (++new_bios_entry >= max_nr_map) break; } 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; } } /* retain count for new bios entries */ new_nr = new_bios_entry; /* 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. */ 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 { u64 start = biosmap->addr; u64 size = biosmap->size; u64 end = start + size; u32 type = biosmap->type; /* Overflow in 64 bits? Ignore the memory map. */ if (start > end) return -1; add_memory_region(start, size, type); } while (biosmap++, --nr_map); return 0; } u64 __init update_memory_range(u64 start, u64 size, unsigned old_type, unsigned new_type) { int i; u64 real_updated_size = 0; BUG_ON(old_type == new_type); for (i = 0; i < e820.nr_map; i++) { struct e820entry *ei = &e820.map[i]; u64 final_start, final_end; if (ei->type != old_type) continue; /* totally covered? */ if (ei->addr >= start && (ei->addr + ei->size) <= (start + size)) { ei->type = new_type; real_updated_size += ei->size; continue; } /* partially covered */ final_start = max(start, ei->addr); final_end = min(start + size, ei->addr + ei->size); if (final_start >= final_end) continue; add_memory_region(final_start, final_end - final_start, new_type); real_updated_size += final_end - final_start; } return real_updated_size; } void __init update_e820(void) { int nr_map; nr_map = e820.nr_map; if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map)) return; e820.nr_map = nr_map; printk(KERN_INFO "modified physical RAM map:\n"); e820_print_map("modified"); } /* * 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 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; } #ifdef CONFIG_X86_64 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"); } #endif /* * 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); }