/* * Low level x86 E820 memory map handling functions. * * The firmware and bootloader passes us the "E820 table", which is the primary * physical memory layout description available about x86 systems. * * The kernel takes the E820 memory layout and optionally modifies it with * quirks and other tweaks, and feeds that into the generic Linux memory * allocation code routines via a platform independent interface (memblock, etc.). */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * We organize the E820 table into two main data structures: * * - 'e820_table_firmware': the original firmware version passed to us by the * bootloader - not modified by the kernel. We use this to: * * - inform the user about the firmware's notion of memory layout * via /sys/firmware/memmap * * - the hibernation code uses it to generate a kernel-independent MD5 * fingerprint of the physical memory layout of a system. * * - kexec, which is a bootloader in disguise, uses the original E820 * layout to pass to the kexec-ed kernel. This way the original kernel * can have a restricted E820 map while the kexec()-ed kexec-kernel * can have access to full memory - etc. * * - 'e820_table': this is the main E820 table that is massaged by the * low level x86 platform code, or modified by boot parameters, before * passed on to higher level MM layers. * * Once the E820 map has been converted to the standard Linux memory layout * information its role stops - modifying it has no effect and does not get * re-propagated. So itsmain role is a temporary bootstrap storage of firmware * specific memory layout data during early bootup. */ static struct e820_table e820_table_init __initdata; static struct e820_table e820_table_firmware_init __initdata; struct e820_table *e820_table __refdata = &e820_table_init; struct e820_table *e820_table_firmware __refdata = &e820_table_firmware_init; /* 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_table->nr_entries; i++) { struct e820_entry *entry = &e820_table->entries[i]; if (type && entry->type != type) continue; if (entry->addr >= end || entry->addr + entry->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 correctly once the E820 table is sorted and * not-overlapping (at least for the range specified), which is the case normally. */ int __init e820_all_mapped(u64 start, u64 end, unsigned type) { int i; for (i = 0; i < e820_table->nr_entries; i++) { struct e820_entry *entry = &e820_table->entries[i]; if (type && entry->type != type) continue; /* Is the region (part) in overlap with the current region? */ if (entry->addr >= end || entry->addr + entry->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 (entry->addr <= start) start = entry->addr + entry->size; /* * If 'start' is now at or beyond 'end', we're done, full * coverage of the desired range exists: */ if (start >= end) return 1; } return 0; } /* * Add a memory region to the kernel E820 map. */ static void __init __e820_add_region(struct e820_table *table, u64 start, u64 size, int type) { int x = table->nr_entries; if (x >= ARRAY_SIZE(table->entries)) { pr_err("e820: too many entries; ignoring [mem %#010llx-%#010llx]\n", start, start + size - 1); return; } table->entries[x].addr = start; table->entries[x].size = size; table->entries[x].type = type; table->nr_entries++; } void __init e820_add_region(u64 start, u64 size, int type) { __e820_add_region(e820_table, start, size, type); } static void __init e820_print_type(u32 type) { switch (type) { case E820_RAM: /* Fall through: */ case E820_RESERVED_KERN: pr_cont("usable"); break; case E820_RESERVED: pr_cont("reserved"); break; case E820_ACPI: pr_cont("ACPI data"); break; case E820_NVS: pr_cont("ACPI NVS"); break; case E820_UNUSABLE: pr_cont("unusable"); break; case E820_PMEM: /* Fall through: */ case E820_PRAM: pr_cont("persistent (type %u)", type); break; default: pr_cont("type %u", type); break; } } void __init e820_print_map(char *who) { int i; for (i = 0; i < e820_table->nr_entries; i++) { pr_info("%s: [mem %#018Lx-%#018Lx] ", who, e820_table->entries[i].addr, e820_table->entries[i].addr + e820_table->entries[i].size - 1); e820_print_type(e820_table->entries[i].type); pr_cont("\n"); } } /* * Sanitize the BIOS E820 map. * * Some E820 responses include overlapping entries. The following * replaces the original E820 map with a new one, removing overlaps, * and resolving conflicting memory types in favor of highest * numbered type. * * The input parameter biosmap points to an array of 'struct * e820_entry' which on entry has elements in the range [0, *pnr_map) * valid, and which has space for up to max_nr_map entries. * On return, the resulting sanitized E820 map entries will be in * overwritten in the same location, starting at biosmap. * * The integer pointed to by pnr_map must be valid on entry (the * current number of valid entries located at biosmap). If the * sanitizing succeeds the *pnr_map will be updated with the new * number of valid entries (something no more than max_nr_map). * * The return value from sanitize_e820_table() is zero if it * successfully 'sanitized' the map entries passed in, and is -1 * if it did nothing, which can happen if either of (1) it was * only passed one map entry, or (2) any of the input map entries * were invalid (start + size < start, meaning that the size was * so big the described memory range wrapped around through zero.) * * 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_ */ struct change_member { /* Pointer to the original BIOS entry: */ struct e820_entry *pbios; /* Address for this change point: */ unsigned long long addr; }; static int __init cpcompare(const void *a, const void *b) { struct change_member * const *app = a, * const *bpp = b; const struct change_member *ap = *app, *bp = *bpp; /* * Inputs are pointers to two elements of change_point[]. If their * addresses are not equal, their difference dominates. If the addresses * are equal, then consider one that represents the end of its region * to be greater than one that does not. */ if (ap->addr != bp->addr) return ap->addr > bp->addr ? 1 : -1; return (ap->addr != ap->pbios->addr) - (bp->addr != bp->pbios->addr); } int __init sanitize_e820_table(struct e820_entry *biosmap, int max_nr_map, u32 *pnr_map) { 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 e820_entry *overlap_list[E820_X_MAX] __initdata; static struct e820_entry new_bios[E820_X_MAX] __initdata; unsigned long current_type, last_type; unsigned long long last_addr; int chgidx; int overlap_entries; int new_bios_entry; int old_nr, new_nr, chg_nr; int i; /* 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 the 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 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): */ sort(change_point, chg_nr, sizeof *change_point, cpcompare, NULL); /* 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 effect 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 || current_type == E820_PRAM) { 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 the original location: */ memcpy(biosmap, new_bios, new_nr*sizeof(struct e820_entry)); *pnr_map = new_nr; return 0; } static int __init __append_e820_table(struct e820_entry *biosmap, int nr_map) { while (nr_map) { u64 start = biosmap->addr; u64 size = biosmap->size; u64 end = start + size - 1; u32 type = biosmap->type; /* Ignore the entry on 64-bit overflow: */ if (start > end && likely(size)) return -1; e820_add_region(start, size, type); biosmap++; nr_map--; } 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. */ static int __init append_e820_table(struct e820_entry *biosmap, int nr_map) { /* Only one memory region (or negative)? Ignore it */ if (nr_map < 2) return -1; return __append_e820_table(biosmap, nr_map); } static u64 __init __e820_update_range(struct e820_table *table, u64 start, u64 size, unsigned old_type, unsigned new_type) { u64 end; unsigned int i; u64 real_updated_size = 0; BUG_ON(old_type == new_type); if (size > (ULLONG_MAX - start)) size = ULLONG_MAX - start; end = start + size; pr_debug("e820: update [mem %#010Lx-%#010Lx] ", start, end - 1); e820_print_type(old_type); pr_cont(" ==> "); e820_print_type(new_type); pr_cont("\n"); for (i = 0; i < table->nr_entries; i++) { struct e820_entry *entry = &table->entries[i]; u64 final_start, final_end; u64 entry_end; if (entry->type != old_type) continue; entry_end = entry->addr + entry->size; /* Completely covered by new range? */ if (entry->addr >= start && entry_end <= end) { entry->type = new_type; real_updated_size += entry->size; continue; } /* New range is completely covered? */ if (entry->addr < start && entry_end > end) { __e820_add_region(table, start, size, new_type); __e820_add_region(table, end, entry_end - end, entry->type); entry->size = start - entry->addr; real_updated_size += size; continue; } /* Partially covered: */ final_start = max(start, entry->addr); final_end = min(end, entry_end); if (final_start >= final_end) continue; __e820_add_region(table, final_start, final_end - final_start, new_type); real_updated_size += final_end - final_start; /* * Left range could be head or tail, so need to update * its size first: */ entry->size -= final_end - final_start; if (entry->addr < final_start) continue; entry->addr = final_end; } return real_updated_size; } u64 __init e820_update_range(u64 start, u64 size, unsigned old_type, unsigned new_type) { return __e820_update_range(e820_table, start, size, old_type, new_type); } static u64 __init e820_update_range_firmware(u64 start, u64 size, unsigned old_type, unsigned new_type) { return __e820_update_range(e820_table_firmware, start, size, old_type, new_type); } /* Remove a range of memory from the E820 table: */ u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type, int checktype) { int i; u64 end; u64 real_removed_size = 0; if (size > (ULLONG_MAX - start)) size = ULLONG_MAX - start; end = start + size; pr_debug("e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1); if (checktype) e820_print_type(old_type); pr_cont("\n"); for (i = 0; i < e820_table->nr_entries; i++) { struct e820_entry *entry = &e820_table->entries[i]; u64 final_start, final_end; u64 entry_end; if (checktype && entry->type != old_type) continue; entry_end = entry->addr + entry->size; /* Completely covered? */ if (entry->addr >= start && entry_end <= end) { real_removed_size += entry->size; memset(entry, 0, sizeof(struct e820_entry)); continue; } /* Is the new range completely covered? */ if (entry->addr < start && entry_end > end) { e820_add_region(end, entry_end - end, entry->type); entry->size = start - entry->addr; real_removed_size += size; continue; } /* Partially covered: */ final_start = max(start, entry->addr); final_end = min(end, entry_end); if (final_start >= final_end) continue; real_removed_size += final_end - final_start; /* * Left range could be head or tail, so need to update * the size first: */ entry->size -= final_end - final_start; if (entry->addr < final_start) continue; entry->addr = final_end; } return real_removed_size; } void __init update_e820(void) { if (sanitize_e820_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries)) return; pr_info("e820: modified physical RAM map:\n"); e820_print_map("modified"); } static void __init update_e820_table_firmware(void) { sanitize_e820_table(e820_table_firmware->entries, ARRAY_SIZE(e820_table_firmware->entries), &e820_table_firmware->nr_entries); } #define MAX_GAP_END 0x100000000ull /* * Search for a gap in the E820 memory space from 0 to MAX_GAP_END (4GB). */ static int __init e820_search_gap(unsigned long *gapstart, unsigned long *gapsize) { unsigned long long last = MAX_GAP_END; int i = e820_table->nr_entries; int found = 0; while (--i >= 0) { unsigned long long start = e820_table->entries[i].addr; unsigned long long end = start + e820_table->entries[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; } return found; } /* * Search for the biggest gap in the low 32 bits of the E820 * memory space. We pass this space to the PCI subsystem, so * that it can 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; int found; gapsize = 0x400000; found = e820_search_gap(&gapstart, &gapsize); if (!found) { #ifdef CONFIG_X86_64 gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024; pr_err( "e820: Cannot find an available gap in the 32-bit address range\n" "e820: PCI devices with unassigned 32-bit BARs may not work!\n"); #else gapstart = 0x10000000; #endif } /* * e820_reserve_resources_late protect stolen RAM already */ pci_mem_start = gapstart; pr_info("e820: [mem %#010lx-%#010lx] available for PCI devices\n", gapstart, gapstart + gapsize - 1); } /* * Called late during init, in free_initmem(). * * Initial e820_table and e820_table_firmware are largish __initdata arrays. * * Copy them to a (usually much smaller) dynamically allocated area that is * sized precisely after the number of e820 entries. * * This is done after we've performed all the fixes and tweaks to the tables. * All functions which modify them are __init functions, which won't exist * after free_initmem(). */ __init void e820_reallocate_tables(void) { struct e820_table *n; int size; size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table->nr_entries; n = kmalloc(size, GFP_KERNEL); BUG_ON(!n); memcpy(n, e820_table, size); e820_table = n; size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries; n = kmalloc(size, GFP_KERNEL); BUG_ON(!n); memcpy(n, e820_table_firmware, size); e820_table_firmware = n; } /* * Because of the small fixed size of struct boot_params, only the first * 128 E820 memory entries are passed to the kernel via boot_params.e820_table, * the remaining (if any) entries are passed via the SETUP_E820_EXT node of * struct setup_data, which is parsed here. */ void __init e820__memory_setup_extended(u64 phys_addr, u32 data_len) { int entries; struct e820_entry *extmap; struct setup_data *sdata; sdata = early_memremap(phys_addr, data_len); entries = sdata->len / sizeof(struct e820_entry); extmap = (struct e820_entry *)(sdata->data); __append_e820_table(extmap, entries); sanitize_e820_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries); early_memunmap(sdata, data_len); pr_info("e820: extended physical RAM map:\n"); e820_print_map("extended"); } /** * Find the ranges of physical addresses that do not correspond to * E820 RAM areas and mark the corresponding pages as 'nosave' for * hibernation (32-bit) or software suspend and suspend to RAM (64-bit). * * This function requires the E820 map to be sorted and without any * overlapping entries. */ void __init e820_mark_nosave_regions(unsigned long limit_pfn) { int i; unsigned long pfn = 0; for (i = 0; i < e820_table->nr_entries; i++) { struct e820_entry *entry = &e820_table->entries[i]; if (pfn < PFN_UP(entry->addr)) register_nosave_region(pfn, PFN_UP(entry->addr)); pfn = PFN_DOWN(entry->addr + entry->size); if (entry->type != E820_RAM && entry->type != E820_RESERVED_KERN) register_nosave_region(PFN_UP(entry->addr), pfn); if (pfn >= limit_pfn) break; } } #ifdef CONFIG_ACPI /* * Register ACPI NVS memory regions, so that we can save/restore them during * hibernation and the subsequent resume: */ static int __init e820_mark_nvs_memory(void) { int i; for (i = 0; i < e820_table->nr_entries; i++) { struct e820_entry *entry = &e820_table->entries[i]; if (entry->type == E820_NVS) acpi_nvs_register(entry->addr, entry->size); } return 0; } core_initcall(e820_mark_nvs_memory); #endif /* * pre allocated 4k and reserved it in memblock and e820_table_firmware */ u64 __init early_reserve_e820(u64 size, u64 align) { u64 addr; addr = __memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE); if (addr) { e820_update_range_firmware(addr, size, E820_RAM, E820_RESERVED); pr_info("e820: update e820_table_firmware for early_reserve_e820\n"); update_e820_table_firmware(); } return addr; } #ifdef CONFIG_X86_32 # ifdef CONFIG_X86_PAE # define MAX_ARCH_PFN (1ULL<<(36-PAGE_SHIFT)) # else # define MAX_ARCH_PFN (1ULL<<(32-PAGE_SHIFT)) # endif #else /* CONFIG_X86_32 */ # define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT #endif /* * Find the highest page frame number we have available */ static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type) { int i; unsigned long last_pfn = 0; unsigned long max_arch_pfn = MAX_ARCH_PFN; for (i = 0; i < e820_table->nr_entries; i++) { struct e820_entry *entry = &e820_table->entries[i]; unsigned long start_pfn; unsigned long end_pfn; if (entry->type != type) continue; start_pfn = entry->addr >> PAGE_SHIFT; end_pfn = (entry->addr + entry->size) >> PAGE_SHIFT; if (start_pfn >= limit_pfn) continue; if (end_pfn > limit_pfn) { last_pfn = limit_pfn; break; } if (end_pfn > last_pfn) last_pfn = end_pfn; } if (last_pfn > max_arch_pfn) last_pfn = max_arch_pfn; pr_info("e820: last_pfn = %#lx max_arch_pfn = %#lx\n", last_pfn, max_arch_pfn); return last_pfn; } unsigned long __init e820_end_of_ram_pfn(void) { return e820_end_pfn(MAX_ARCH_PFN, E820_RAM); } unsigned long __init e820_end_of_low_ram_pfn(void) { return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_RAM); } static void __init early_panic(char *msg) { early_printk(msg); panic(msg); } static int userdef __initdata; /* The "mem=nopentium" boot option disables 4MB page tables on 32-bit kernels: */ static int __init parse_memopt(char *p) { u64 mem_size; if (!p) return -EINVAL; if (!strcmp(p, "nopentium")) { #ifdef CONFIG_X86_32 setup_clear_cpu_cap(X86_FEATURE_PSE); return 0; #else pr_warn("mem=nopentium ignored! (only supported on x86_32)\n"); return -EINVAL; #endif } userdef = 1; mem_size = memparse(p, &p); /* Don't remove all memory when getting "mem={invalid}" parameter: */ if (mem_size == 0) return -EINVAL; e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1); return 0; } early_param("mem", parse_memopt); static int __init parse_memmap_one(char *p) { char *oldp; u64 start_at, mem_size; if (!p) return -EINVAL; if (!strncmp(p, "exactmap", 8)) { #ifdef CONFIG_CRASH_DUMP /* * If we are doing a crash dump, we still need to know * the real memory size before the original memory map is * reset. */ saved_max_pfn = e820_end_of_ram_pfn(); #endif e820_table->nr_entries = 0; userdef = 1; return 0; } oldp = p; mem_size = memparse(p, &p); if (p == oldp) return -EINVAL; userdef = 1; if (*p == '@') { start_at = memparse(p+1, &p); e820_add_region(start_at, mem_size, E820_RAM); } else if (*p == '#') { start_at = memparse(p+1, &p); e820_add_region(start_at, mem_size, E820_ACPI); } else if (*p == '$') { start_at = memparse(p+1, &p); e820_add_region(start_at, mem_size, E820_RESERVED); } else if (*p == '!') { start_at = memparse(p+1, &p); e820_add_region(start_at, mem_size, E820_PRAM); } else { e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1); } return *p == '\0' ? 0 : -EINVAL; } static int __init parse_memmap_opt(char *str) { while (str) { char *k = strchr(str, ','); if (k) *k++ = 0; parse_memmap_one(str); str = k; } return 0; } early_param("memmap", parse_memmap_opt); void __init e820_reserve_setup_data(void) { struct setup_data *data; u64 pa_data; pa_data = boot_params.hdr.setup_data; if (!pa_data) return; while (pa_data) { data = early_memremap(pa_data, sizeof(*data)); e820_update_range(pa_data, sizeof(*data)+data->len, E820_RAM, E820_RESERVED_KERN); pa_data = data->next; early_memunmap(data, sizeof(*data)); } sanitize_e820_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries); memcpy(e820_table_firmware, e820_table, sizeof(struct e820_table)); printk(KERN_INFO "extended physical RAM map:\n"); e820_print_map("reserve setup_data"); } /* * Called after parse_early_param(), after early parameters (such as mem=) * have been processed, in which case we already have an E820 table filled in * via the parameter callback function(s), but it's not sorted and printed yet: */ void __init e820__finish_early_params(void) { if (userdef) { if (sanitize_e820_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries) < 0) early_panic("Invalid user supplied memory map"); pr_info("e820: user-defined physical RAM map:\n"); e820_print_map("user"); } } static const char *__init e820_type_to_string(int e820_type) { switch (e820_type) { case E820_RESERVED_KERN: /* Fall-through: */ case E820_RAM: return "System RAM"; case E820_ACPI: return "ACPI Tables"; case E820_NVS: return "ACPI Non-volatile Storage"; case E820_UNUSABLE: return "Unusable memory"; case E820_PRAM: return "Persistent Memory (legacy)"; case E820_PMEM: return "Persistent Memory"; default: return "Reserved"; } } static unsigned long __init e820_type_to_iomem_type(int e820_type) { switch (e820_type) { case E820_RESERVED_KERN: /* Fall-through: */ case E820_RAM: return IORESOURCE_SYSTEM_RAM; case E820_ACPI: /* Fall-through: */ case E820_NVS: /* Fall-through: */ case E820_UNUSABLE: /* Fall-through: */ case E820_PRAM: /* Fall-through: */ case E820_PMEM: /* Fall-through: */ default: return IORESOURCE_MEM; } } static unsigned long __init e820_type_to_iores_desc(int e820_type) { switch (e820_type) { case E820_ACPI: return IORES_DESC_ACPI_TABLES; case E820_NVS: return IORES_DESC_ACPI_NV_STORAGE; case E820_PMEM: return IORES_DESC_PERSISTENT_MEMORY; case E820_PRAM: return IORES_DESC_PERSISTENT_MEMORY_LEGACY; case E820_RESERVED_KERN: /* Fall-through: */ case E820_RAM: /* Fall-through: */ case E820_UNUSABLE: /* Fall-through: */ default: return IORES_DESC_NONE; } } static bool __init do_mark_busy(u32 type, struct resource *res) { /* this is the legacy bios/dos rom-shadow + mmio region */ if (res->start < (1ULL<<20)) return true; /* * Treat persistent memory like device memory, i.e. reserve it * for exclusive use of a driver */ switch (type) { case E820_RESERVED: case E820_PRAM: case E820_PMEM: return false; default: return true; } } /* * Mark E820 reserved areas as busy for the resource manager: */ static struct resource __initdata *e820_res; void __init e820_reserve_resources(void) { int i; struct resource *res; u64 end; res = alloc_bootmem(sizeof(struct resource) * e820_table->nr_entries); e820_res = res; for (i = 0; i < e820_table->nr_entries; i++) { end = e820_table->entries[i].addr + e820_table->entries[i].size - 1; if (end != (resource_size_t)end) { res++; continue; } res->name = e820_type_to_string(e820_table->entries[i].type); res->start = e820_table->entries[i].addr; res->end = end; res->flags = e820_type_to_iomem_type(e820_table->entries[i].type); res->desc = e820_type_to_iores_desc(e820_table->entries[i].type); /* * don't register the region that could be conflicted with * pci device BAR resource and insert them later in * pcibios_resource_survey() */ if (do_mark_busy(e820_table->entries[i].type, res)) { res->flags |= IORESOURCE_BUSY; insert_resource(&iomem_resource, res); } res++; } for (i = 0; i < e820_table_firmware->nr_entries; i++) { struct e820_entry *entry = &e820_table_firmware->entries[i]; firmware_map_add_early(entry->addr, entry->addr + entry->size, e820_type_to_string(entry->type)); } } /* How much should we pad RAM ending depending on where it is? */ static unsigned long __init ram_alignment(resource_size_t pos) { unsigned long mb = pos >> 20; /* To 64kB in the first megabyte */ if (!mb) return 64*1024; /* To 1MB in the first 16MB */ if (mb < 16) return 1024*1024; /* To 64MB for anything above that */ return 64*1024*1024; } #define MAX_RESOURCE_SIZE ((resource_size_t)-1) void __init e820_reserve_resources_late(void) { int i; struct resource *res; res = e820_res; for (i = 0; i < e820_table->nr_entries; i++) { if (!res->parent && res->end) insert_resource_expand_to_fit(&iomem_resource, res); res++; } /* * Try to bump up RAM regions to reasonable boundaries, to * avoid stolen RAM: */ for (i = 0; i < e820_table->nr_entries; i++) { struct e820_entry *entry = &e820_table->entries[i]; u64 start, end; if (entry->type != E820_RAM) continue; start = entry->addr + entry->size; end = round_up(start, ram_alignment(start)) - 1; if (end > MAX_RESOURCE_SIZE) end = MAX_RESOURCE_SIZE; if (start >= end) continue; pr_debug("e820: reserve RAM buffer [mem %#010llx-%#010llx]\n", start, end); reserve_region_with_split(&iomem_resource, start, end, "RAM buffer"); } } /* * Pass the firmware (bootloader) E820 map to the kernel and process it: */ char *__init e820__memory_setup_default(void) { char *who = "BIOS-e820"; u32 new_nr; /* * 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 */ new_nr = boot_params.e820_entries; sanitize_e820_table(boot_params.e820_table, ARRAY_SIZE(boot_params.e820_table), &new_nr); boot_params.e820_entries = new_nr; if (append_e820_table(boot_params.e820_table, boot_params.e820_entries) < 0) { u64 mem_size; /* Compare results from other methods and take the one that gives more RAM: */ if (boot_params.alt_mem_k < boot_params.screen_info.ext_mem_k) { mem_size = boot_params.screen_info.ext_mem_k; who = "BIOS-88"; } else { mem_size = boot_params.alt_mem_k; who = "BIOS-e801"; } e820_table->nr_entries = 0; e820_add_region(0, LOWMEMSIZE(), E820_RAM); e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM); } return who; } /* * Calls e820__memory_setup_default() in essence to pick up the firmware/bootloader * E820 map - with an optional platform quirk available for virtual platforms * to override this method of boot environment processing: */ void __init e820__memory_setup(void) { char *who; who = x86_init.resources.memory_setup(); memcpy(e820_table_firmware, e820_table, sizeof(struct e820_table)); pr_info("e820: BIOS-provided physical RAM map:\n"); e820_print_map(who); } void __init e820__memblock_setup(void) { int i; u64 end; /* * The bootstrap memblock region count maximum is 128 entries * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries * than that - so allow memblock resizing. * * This is safe, because this call happens pretty late during x86 setup, * so we know about reserved memory regions already. (This is important * so that memblock resizing does no stomp over reserved areas.) */ memblock_allow_resize(); for (i = 0; i < e820_table->nr_entries; i++) { struct e820_entry *entry = &e820_table->entries[i]; end = entry->addr + entry->size; if (end != (resource_size_t)end) continue; if (entry->type != E820_RAM && entry->type != E820_RESERVED_KERN) continue; memblock_add(entry->addr, entry->size); } /* Throw away partial pages: */ memblock_trim_memory(PAGE_SIZE); memblock_dump_all(); }