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Diffstat (limited to 'arch/x86/kernel/e820.c')
| -rw-r--r-- | arch/x86/kernel/e820.c | 1380 |
1 files changed, 1380 insertions, 0 deletions
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c new file mode 100644 index 000000000..eb72537bc --- /dev/null +++ b/arch/x86/kernel/e820.c @@ -0,0 +1,1380 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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 <linux/memblock.h> +#include <linux/suspend.h> +#include <linux/acpi.h> +#include <linux/firmware-map.h> +#include <linux/sort.h> +#include <linux/kvm_types.h> + +#include <asm/e820/api.h> +#include <asm/setup.h> + +/* + * We organize the E820 table into three main data structures: + * + * - 'e820_table_firmware': the original firmware version passed to us by the + * bootloader - not modified by the kernel. It is composed of two parts: + * the first 128 E820 memory entries in boot_params.e820_table and the remaining + * (if any) entries of the SETUP_E820_EXT nodes. We use this to: + * + * - the hibernation code uses it to generate a kernel-independent CRC32 + * checksum of the physical memory layout of a system. + * + * - 'e820_table_kexec': a slightly modified (by the kernel) firmware version + * passed to us by the bootloader - the major difference between + * e820_table_firmware[] and this one is that e820_table_kexec[] + * might be modified by the kexec itself to fake an mptable. + * We use this to: + * + * - 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. + * + * Export the memory layout via /sys/firmware/memmap. kexec-tools uses + * the entries to create an E820 table for the kexec kernel. + * + * kexec_file_load in-kernel code uses the table for the kexec kernel. + * + * - '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 its main role is a temporary bootstrap storage of firmware + * specific memory layout data during early bootup. + */ +__initdata static struct e820_table e820_table_init; +__initdata static struct e820_table e820_table_kexec_init; +__initdata static struct e820_table e820_table_firmware_init; + +__refdata struct e820_table *e820_table = &e820_table_init; +__refdata struct e820_table *e820_table_kexec = &e820_table_kexec_init; +__refdata struct e820_table *e820_table_firmware = &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 <start,end> is mapped + * with type. + */ +static bool _e820__mapped_any(struct e820_table *table, + u64 start, u64 end, enum e820_type type) +{ + u32 idx; + + for (idx = 0; idx < table->nr_entries; idx++) { + struct e820_entry *entry = &table->entries[idx]; + + if (type && entry->type != type) + continue; + if (entry->addr >= end || entry->addr + entry->size <= start) + continue; + return true; + } + return false; +} + +bool e820__mapped_raw_any(u64 start, u64 end, enum e820_type type) +{ + return _e820__mapped_any(e820_table_firmware, start, end, type); +} +EXPORT_SYMBOL_FOR_KVM(e820__mapped_raw_any); + +bool e820__mapped_any(u64 start, u64 end, enum e820_type type) +{ + return _e820__mapped_any(e820_table, start, end, type); +} +EXPORT_SYMBOL_GPL(e820__mapped_any); + +/* + * This function checks if the entire <start,end> 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. + */ +static struct e820_entry *__e820__mapped_all(u64 start, u64 end, + enum e820_type type) +{ + u32 idx; + + for (idx = 0; idx < e820_table->nr_entries; idx++) { + struct e820_entry *entry = &e820_table->entries[idx]; + + 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 <start,end> 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 entry; + } + + return NULL; +} + +/* + * This function checks if the entire range <start,end> is mapped with type. + */ +__init bool e820__mapped_all(u64 start, u64 end, enum e820_type type) +{ + return __e820__mapped_all(start, end, type); +} + +/* + * This function returns the type associated with the range <start,end>. + */ +int e820__get_entry_type(u64 start, u64 end) +{ + struct e820_entry *entry = __e820__mapped_all(start, end, 0); + + return entry ? entry->type : -EINVAL; +} + +/* + * Add a memory region to the kernel E820 map. + */ +__init static void __e820__range_add(struct e820_table *table, u64 start, u64 size, enum e820_type type) +{ + u32 idx = table->nr_entries; + struct e820_entry *entry_new; + + if (idx >= ARRAY_SIZE(table->entries)) { + pr_err("E820 table full; ignoring [mem %#010llx-%#010llx]\n", + start, start + size-1); + return; + } + + entry_new = table->entries + idx; + + entry_new->addr = start; + entry_new->size = size; + entry_new->type = type; + + table->nr_entries++; +} + +__init void e820__range_add(u64 start, u64 size, enum e820_type type) +{ + __e820__range_add(e820_table, start, size, type); +} + +__init static void e820_print_type(enum e820_type type) +{ + switch (type) { + case E820_TYPE_RAM: pr_cont(" System RAM"); break; + case E820_TYPE_RESERVED: pr_cont(" device reserved"); break; + case E820_TYPE_SOFT_RESERVED: pr_cont(" soft reserved"); break; + case E820_TYPE_ACPI: pr_cont(" ACPI data"); break; + case E820_TYPE_NVS: pr_cont(" ACPI NVS"); break; + case E820_TYPE_UNUSABLE: pr_cont(" unusable"); break; + case E820_TYPE_PMEM: /* Fall through: */ + case E820_TYPE_PRAM: pr_cont(" persistent RAM (type %u)", type); break; + default: pr_cont(" type %u", type); break; + } +} + +__init static void e820__print_table(const char *who) +{ + u64 range_end_prev = 0; + u32 idx; + + for (idx = 0; idx < e820_table->nr_entries; idx++) { + struct e820_entry *entry = e820_table->entries + idx; + u64 range_start, range_end; + + range_start = entry->addr; + range_end = entry->addr + entry->size; + + /* Out of order E820 maps should not happen: */ + if (range_start < range_end_prev) + pr_info(FW_BUG "out of order E820 entry!\n"); + + if (range_start > range_end_prev) { + pr_info("%s: [gap %#018Lx-%#018Lx]\n", + who, + range_end_prev, + range_start-1); + } + + pr_info("%s: [mem %#018Lx-%#018Lx] ", who, range_start, range_end-1); + e820_print_type(entry->type); + pr_cont("\n"); + + range_end_prev = range_end; + } +} + +/* + * Sanitize an E820 map. + * + * Some E820 layouts 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 'entries' points to an array of 'struct + * e820_entry' which on entry has elements in the range [0, *nr_entries) + * valid, and which has space for up to max_nr_entries entries. + * On return, the resulting sanitized E820 map entries will be in + * overwritten in the same location, starting at 'entries'. + * + * The integer pointed to by nr_entries must be valid on entry (the + * current number of valid entries located at 'entries'). If the + * sanitizing succeeds the *nr_entries will be updated with the new + * number of valid entries (something no more than max_nr_entries). + * + * The return value from e820__update_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 entry: */ + struct e820_entry *entry; + /* Address for this change point: */ + u64 addr; +}; + +__initdata static struct change_member change_point_list[2*E820_MAX_ENTRIES]; +__initdata static struct change_member *change_point[2*E820_MAX_ENTRIES]; +__initdata static struct e820_entry *overlap_list[E820_MAX_ENTRIES]; +__initdata static struct e820_entry new_entries[E820_MAX_ENTRIES]; + +__init static int 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->entry->addr) - (bp->addr != bp->entry->addr); +} + +/* + * Can two consecutive E820 entries of this same E820 type be merged? + */ +static bool e820_type_mergeable(enum e820_type type) +{ + /* + * These types may indicate distinct platform ranges aligned to + * NUMA node, protection domain, performance domain, or other + * boundaries. Do not merge them. + */ + if (type == E820_TYPE_PRAM) + return false; + if (type == E820_TYPE_SOFT_RESERVED) + return false; + + return true; +} + +__init int e820__update_table(struct e820_table *table) +{ + struct e820_entry *entries = table->entries; + u32 max_nr_entries = ARRAY_SIZE(table->entries); + enum e820_type current_type, last_type; + u64 last_addr; + u32 new_nr_entries, overlap_entries; + u32 idx, chg_idx, chg_nr; + + /* If there's only one memory region, don't bother: */ + if (table->nr_entries < 2) + return -1; + + BUG_ON(table->nr_entries > max_nr_entries); + + /* Bail out if we find any unreasonable addresses in the map: */ + for (idx = 0; idx < table->nr_entries; idx++) { + if (entries[idx].addr + entries[idx].size < entries[idx].addr) + return -1; + } + + /* Create pointers for initial change-point information (for sorting): */ + for (idx = 0; idx < 2 * table->nr_entries; idx++) + change_point[idx] = &change_point_list[idx]; + + /* + * Record all known change-points (starting and ending addresses), + * omitting empty memory regions: + */ + chg_idx = 0; + for (idx = 0; idx < table->nr_entries; idx++) { + if (entries[idx].size != 0) { + change_point[chg_idx]->addr = entries[idx].addr; + change_point[chg_idx++]->entry = &entries[idx]; + change_point[chg_idx]->addr = entries[idx].addr + entries[idx].size; + change_point[chg_idx++]->entry = &entries[idx]; + } + } + chg_nr = chg_idx; + + /* Sort change-point list by memory addresses (low -> high): */ + sort(change_point, chg_nr, sizeof(*change_point), cpcompare, NULL); + + /* Create a new memory map, removing overlaps: */ + overlap_entries = 0; /* Number of entries in the overlap table */ + new_nr_entries = 0; /* Index for creating new 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 map: */ + for (chg_idx = 0; chg_idx < chg_nr; chg_idx++) { + /* Keep track of all overlapping entries */ + if (change_point[chg_idx]->addr == change_point[chg_idx]->entry->addr) { + /* Add map entry to overlap list (> 1 entry implies an overlap) */ + overlap_list[overlap_entries++] = change_point[chg_idx]->entry; + } else { + /* Remove entry from list (order independent, so swap with last): */ + for (idx = 0; idx < overlap_entries; idx++) { + if (overlap_list[idx] == change_point[chg_idx]->entry) + overlap_list[idx] = 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 (idx = 0; idx < overlap_entries; idx++) { + if (overlap_list[idx]->type > current_type) + current_type = overlap_list[idx]->type; + } + + /* Continue building up new map based on this information: */ + if (current_type != last_type || !e820_type_mergeable(current_type)) { + if (last_type) { + new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr; + /* Move forward only if the new size was non-zero: */ + if (new_entries[new_nr_entries].size != 0) + /* No more space left for new entries? */ + if (++new_nr_entries >= max_nr_entries) + break; + } + if (current_type) { + new_entries[new_nr_entries].addr = change_point[chg_idx]->addr; + new_entries[new_nr_entries].type = current_type; + last_addr = change_point[chg_idx]->addr; + } + last_type = current_type; + } + } + + /* Copy the new entries into the original location: */ + memcpy(entries, new_entries, new_nr_entries*sizeof(*entries)); + table->nr_entries = new_nr_entries; + + return 0; +} + +/* + * Copy the BIOS E820 map into the kernel's e820_table. + * + * Sanity-check it while we're at it.. + */ +__init static int append_e820_table(struct boot_e820_entry *entries, u32 nr_entries) +{ + struct boot_e820_entry *entry = entries; + + /* If there aren't any entries, we'll want to fall back to another source: */ + if (!nr_entries) + return -ENOENT; + + while (nr_entries) { + u64 start = entry->addr; + u64 size = entry->size; + u64 end = start + size-1; + u32 type = entry->type; + + /* Ignore the remaining entries on 64-bit overflow: */ + if (start > end && likely(size)) + return -EINVAL; + + e820__range_add(start, size, type); + + entry++; + nr_entries--; + } + return 0; +} + +__init static u64 +__e820__range_update(struct e820_table *table, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type) +{ + u64 end; + u32 idx; + u64 real_updated_size = 0; + + BUG_ON(old_type == new_type); + + if (size > (ULLONG_MAX - start)) + size = ULLONG_MAX - start; + + end = start + size; + printk(KERN_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 (idx = 0; idx < table->nr_entries; idx++) { + struct e820_entry *entry = &table->entries[idx]; + 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__range_add(table, start, size, new_type); + __e820__range_add(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__range_add(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; +} + +__init u64 e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type) +{ + return __e820__range_update(e820_table, start, size, old_type, new_type); +} + +__init u64 e820__range_update_table(struct e820_table *t, u64 start, u64 size, + enum e820_type old_type, enum e820_type new_type) +{ + return __e820__range_update(t, start, size, old_type, new_type); +} + +/* Remove a range of memory from the E820 table: */ +__init void e820__range_remove(u64 start, u64 size, enum e820_type filter_type) +{ + u32 idx; + u64 end; + + if (size > (ULLONG_MAX - start)) + size = ULLONG_MAX - start; + + end = start + size; + printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx]", start, end - 1); + if (filter_type) + e820_print_type(filter_type); + pr_cont("\n"); + + for (idx = 0; idx < e820_table->nr_entries; idx++) { + struct e820_entry *entry = &e820_table->entries[idx]; + u64 final_start, final_end; + u64 entry_end; + + if (filter_type && entry->type != filter_type) + continue; + + entry_end = entry->addr + entry->size; + + /* Completely covered? */ + if (entry->addr >= start && entry_end <= end) { + memset(entry, 0, sizeof(*entry)); + continue; + } + + /* Is the new range completely covered? */ + if (entry->addr < start && entry_end > end) { + e820__range_add(end, entry_end - end, entry->type); + entry->size = start - entry->addr; + continue; + } + + /* Partially covered: */ + final_start = max(start, entry->addr); + final_end = min(end, entry_end); + if (final_start >= final_end) + continue; + + /* + * 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; + } +} + +__init void e820__update_table_print(void) +{ + if (e820__update_table(e820_table)) + return; + + pr_info("modified physical RAM map:\n"); + e820__print_table("modified"); +} + +__init static void e820__update_table_kexec(void) +{ + e820__update_table(e820_table_kexec); +} + +#define MAX_GAP_END SZ_4G + +/* + * Search for a gap in the E820 memory space from 0 to MAX_GAP_END (4GB). + */ +__init static int e820_search_gap(unsigned long *max_gap_start, unsigned long *max_gap_size) +{ + struct e820_entry *entry; + u64 range_end_prev = 0; + int found = 0; + u32 idx; + + for (idx = 0; idx < e820_table->nr_entries; idx++) { + u64 range_start, range_end; + + entry = e820_table->entries + idx; + range_start = entry->addr; + range_end = entry->addr + entry->size; + + /* Process any gap before this entry: */ + if (range_start > range_end_prev) { + u64 gap_start = range_end_prev; + u64 gap_end = range_start; + u64 gap_size; + + if (gap_start < MAX_GAP_END) { + /* Make sure the entirety of the gap is below MAX_GAP_END: */ + gap_end = min(gap_end, MAX_GAP_END); + gap_size = gap_end-gap_start; + + if (gap_size >= *max_gap_size) { + *max_gap_start = gap_start; + *max_gap_size = gap_size; + found = 1; + } + } + } + + range_end_prev = range_end; + } + + /* Is there a usable gap beyond the last entry: */ + if (entry->addr + entry->size < MAX_GAP_END) { + u64 gap_start = entry->addr + entry->size; + u64 gap_size = MAX_GAP_END-gap_start; + + if (gap_size >= *max_gap_size) { + *max_gap_start = gap_start; + *max_gap_size = gap_size; + found = 1; + } + } + + 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_pci_gap(void) +{ + unsigned long max_gap_start, max_gap_size; + int found; + + /* The minimum eligible gap size is 4MB: */ + max_gap_size = SZ_4M; + found = e820_search_gap(&max_gap_start, &max_gap_size); + + if (!found) { +#ifdef CONFIG_X86_64 + max_gap_start = (max_pfn << PAGE_SHIFT) + SZ_1M; + pr_err("Cannot find an available gap in the 32-bit address range\n"); + pr_err("PCI devices with unassigned 32-bit BARs may not work!\n"); +#else + max_gap_start = SZ_256M; +#endif + } + + /* + * e820__reserve_resources_late() protects stolen RAM already: + */ + pci_mem_start = max_gap_start; + + pr_info("[gap %#010lx-%#010lx] available for PCI devices\n", + max_gap_start, max_gap_start + max_gap_size-1); +} + +/* + * Called late during init, in free_initmem(). + * + * Initial e820_table and e820_table_kexec 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 = kmemdup(e820_table, size, GFP_KERNEL); + BUG_ON(!n); + e820_table = n; + + size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_kexec->nr_entries; + n = kmemdup(e820_table_kexec, size, GFP_KERNEL); + BUG_ON(!n); + e820_table_kexec = n; + + size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries; + n = kmemdup(e820_table_firmware, size, GFP_KERNEL); + BUG_ON(!n); + 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. + */ +__init void e820__memory_setup_extended(u64 phys_addr, u32 data_len) +{ + int entries; + struct boot_e820_entry *extmap; + struct setup_data *sdata; + + sdata = early_memremap(phys_addr, data_len); + entries = sdata->len / sizeof(*extmap); + extmap = (struct boot_e820_entry *)(sdata->data); + + append_e820_table(extmap, entries); + e820__update_table(e820_table); + + memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec)); + memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware)); + + early_memunmap(sdata, data_len); + pr_info("extended physical RAM map:\n"); + e820__print_table("extended"); +} + +/* + * Find the ranges of physical addresses that do not correspond to + * E820 RAM areas and register 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. + */ +__init void e820__register_nosave_regions(unsigned long limit_pfn) +{ + u32 idx; + u64 last_addr = 0; + + for (idx = 0; idx < e820_table->nr_entries; idx++) { + struct e820_entry *entry = &e820_table->entries[idx]; + + if (entry->type != E820_TYPE_RAM) + continue; + + if (last_addr < entry->addr) + register_nosave_region(PFN_DOWN(last_addr), PFN_UP(entry->addr)); + + last_addr = entry->addr + entry->size; + } + + register_nosave_region(PFN_DOWN(last_addr), limit_pfn); +} + +#ifdef CONFIG_ACPI +/* + * Register ACPI NVS memory regions, so that we can save/restore them during + * hibernation and the subsequent resume: + */ +__init static int e820__register_nvs_regions(void) +{ + u32 idx; + + for (idx = 0; idx < e820_table->nr_entries; idx++) { + struct e820_entry *entry = &e820_table->entries[idx]; + + if (entry->type == E820_TYPE_NVS) + acpi_nvs_register(entry->addr, entry->size); + } + + return 0; +} +core_initcall(e820__register_nvs_regions); +#endif + +/* + * Allocate the requested number of bytes with the requested alignment + * and return (the physical address) to the caller. Also register this + * range in the 'kexec' E820 table as a reserved range. + * + * This allows kexec to fake a new mptable, as if it came from the real + * system. + */ +__init u64 e820__memblock_alloc_reserved(u64 size, u64 align) +{ + u64 addr; + + addr = memblock_phys_alloc(size, align); + if (addr) { + e820__range_update_table(e820_table_kexec, addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED); + pr_info("update e820_table_kexec for e820__memblock_alloc_reserved()\n"); + e820__update_table_kexec(); + } + + 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 + */ +__init static unsigned long e820__end_ram_pfn(unsigned long limit_pfn) +{ + u32 idx; + unsigned long last_pfn = 0; + unsigned long max_arch_pfn = MAX_ARCH_PFN; + + for (idx = 0; idx < e820_table->nr_entries; idx++) { + struct e820_entry *entry = &e820_table->entries[idx]; + unsigned long start_pfn; + unsigned long end_pfn; + + if (entry->type != E820_TYPE_RAM && + entry->type != E820_TYPE_ACPI) + 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("last_pfn = %#lx max_arch_pfn = %#lx\n", + last_pfn, max_arch_pfn); + return last_pfn; +} + +__init unsigned long e820__end_of_ram_pfn(void) +{ + return e820__end_ram_pfn(MAX_ARCH_PFN); +} + +__init unsigned long e820__end_of_low_ram_pfn(void) +{ + return e820__end_ram_pfn(1UL << (32 - PAGE_SHIFT)); +} + +__initdata static int userdef; + +/* The "mem=nopentium" boot option disables 4MB page tables on 32-bit kernels: */ +__init static int 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__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM); + +#ifdef CONFIG_MEMORY_HOTPLUG + max_mem_size = mem_size; +#endif + + return 0; +} +early_param("mem", parse_memopt); + +__init static int parse_memmap_one(char *p) +{ + char *oldp; + u64 start_at, mem_size; + + if (!p) + return -EINVAL; + + if (!strncmp(p, "exactmap", 8)) { + 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__range_add(start_at, mem_size, E820_TYPE_RAM); + } else if (*p == '#') { + start_at = memparse(p+1, &p); + e820__range_add(start_at, mem_size, E820_TYPE_ACPI); + } else if (*p == '$') { + start_at = memparse(p+1, &p); + e820__range_add(start_at, mem_size, E820_TYPE_RESERVED); + } else if (*p == '!') { + start_at = memparse(p+1, &p); + e820__range_add(start_at, mem_size, E820_TYPE_PRAM); + } else if (*p == '%') { + enum e820_type from = 0, to = 0; + + start_at = memparse(p + 1, &p); + if (*p == '-') + from = simple_strtoull(p + 1, &p, 0); + if (*p == '+') + to = simple_strtoull(p + 1, &p, 0); + if (*p != '\0') + return -EINVAL; + if (from && to) + e820__range_update(start_at, mem_size, from, to); + else if (to) + e820__range_add(start_at, mem_size, to); + else + e820__range_remove(start_at, mem_size, from); + } else { + e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM); + } + + return *p == '\0' ? 0 : -EINVAL; +} + +__init static int 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); + +/* + * 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: + */ +__init void e820__finish_early_params(void) +{ + if (userdef) { + if (e820__update_table(e820_table) < 0) + panic("Invalid user supplied memory map"); + + pr_info("user-defined physical RAM map:\n"); + e820__print_table("user"); + } +} + +__init static const char * e820_type_to_string(struct e820_entry *entry) +{ + switch (entry->type) { + case E820_TYPE_RAM: return "System RAM"; + case E820_TYPE_ACPI: return "ACPI Tables"; + case E820_TYPE_NVS: return "ACPI Non-volatile Storage"; + case E820_TYPE_UNUSABLE: return "Unusable memory"; + case E820_TYPE_PRAM: return "Persistent Memory (legacy)"; + case E820_TYPE_PMEM: return "Persistent Memory"; + case E820_TYPE_RESERVED: return "Reserved"; + case E820_TYPE_SOFT_RESERVED: return "Soft Reserved"; + default: return "Unknown E820 type"; + } +} + +__init static unsigned long e820_type_to_iomem_type(struct e820_entry *entry) +{ + switch (entry->type) { + case E820_TYPE_RAM: return IORESOURCE_SYSTEM_RAM; + case E820_TYPE_ACPI: /* Fall-through: */ + case E820_TYPE_NVS: /* Fall-through: */ + case E820_TYPE_UNUSABLE: /* Fall-through: */ + case E820_TYPE_PRAM: /* Fall-through: */ + case E820_TYPE_PMEM: /* Fall-through: */ + case E820_TYPE_RESERVED: /* Fall-through: */ + case E820_TYPE_SOFT_RESERVED: /* Fall-through: */ + default: return IORESOURCE_MEM; + } +} + +__init static unsigned long e820_type_to_iores_desc(struct e820_entry *entry) +{ + switch (entry->type) { + case E820_TYPE_ACPI: return IORES_DESC_ACPI_TABLES; + case E820_TYPE_NVS: return IORES_DESC_ACPI_NV_STORAGE; + case E820_TYPE_PMEM: return IORES_DESC_PERSISTENT_MEMORY; + case E820_TYPE_PRAM: return IORES_DESC_PERSISTENT_MEMORY_LEGACY; + case E820_TYPE_RESERVED: return IORES_DESC_RESERVED; + case E820_TYPE_SOFT_RESERVED: return IORES_DESC_SOFT_RESERVED; + case E820_TYPE_RAM: /* Fall-through: */ + case E820_TYPE_UNUSABLE: /* Fall-through: */ + default: return IORES_DESC_NONE; + } +} + +/* + * We assign one resource entry for each E820 map entry: + */ +__initdata static struct resource *e820_res; + +/* + * Is this a device address region that should not be marked busy? + * (Versus system address regions that we register & lock early.) + */ +__init static bool e820_device_region(enum e820_type type, struct resource *res) +{ + /* This is the legacy BIOS/DOS ROM-shadow + MMIO region: */ + if (res->start < SZ_1M) + return false; + + /* + * Treat persistent memory and other special memory ranges like + * device memory, i.e. keep it available for exclusive use of a + * driver: + */ + switch (type) { + case E820_TYPE_RESERVED: + case E820_TYPE_SOFT_RESERVED: + case E820_TYPE_PRAM: + case E820_TYPE_PMEM: + return true; + case E820_TYPE_RAM: + case E820_TYPE_ACPI: + case E820_TYPE_NVS: + case E820_TYPE_UNUSABLE: + default: + return false; + } +} + +/* + * Mark E820 system regions as busy for the resource manager: + */ +__init void e820__reserve_resources(void) +{ + u32 idx; + struct resource *res; + u64 end; + + res = memblock_alloc_or_panic(sizeof(*res) * e820_table->nr_entries, + SMP_CACHE_BYTES); + e820_res = res; + + for (idx = 0; idx < e820_table->nr_entries; idx++) { + struct e820_entry *entry = e820_table->entries + idx; + + end = entry->addr + entry->size - 1; + if (end != (resource_size_t)end) { + res++; + continue; + } + res->start = entry->addr; + res->end = end; + res->name = e820_type_to_string(entry); + res->flags = e820_type_to_iomem_type(entry); + res->desc = e820_type_to_iores_desc(entry); + + /* + * Skip and don't register device regions that could be conflicted + * with PCI device BAR resources. They get inserted later in + * pcibios_resource_survey() -> e820__reserve_resources_late(): + */ + if (!e820_device_region(entry->type, res)) { + res->flags |= IORESOURCE_BUSY; + insert_resource(&iomem_resource, res); + } + res++; + } + + /* Expose the kexec e820 table to sysfs: */ + for (idx = 0; idx < e820_table_kexec->nr_entries; idx++) { + struct e820_entry *entry = e820_table_kexec->entries + idx; + + firmware_map_add_early(entry->addr, entry->addr + entry->size, e820_type_to_string(entry)); + } +} + +/* + * How much should we pad the end of RAM, depending on where it is? + */ +__init static unsigned long 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) + +__init void e820__reserve_resources_late(void) +{ + /* + * Register device address regions listed in the E820 map, + * these can be claimed by device drivers later on: + */ + for (u32 idx = 0; idx < e820_table->nr_entries; idx++) { + struct resource *res = e820_res + idx; + + /* skip added or uninitialized resources */ + if (res->parent || !res->end) + continue; + + /* set aside soft-reserved resources for driver consideration */ + if (res->desc == IORES_DESC_SOFT_RESERVED) { + insert_resource_expand_to_fit(&soft_reserve_resource, res); + } else { + /* publish the rest immediately */ + insert_resource_expand_to_fit(&iomem_resource, res); + } + } + + /* + * Create additional 'gaps' at the end of RAM regions, + * rounding them up to 64k/1MB/64MB boundaries, should + * they be weirdly sized, and register extra, locked + * resource regions for them, to make sure drivers + * won't claim those addresses. + * + * These are basically blind guesses and heuristics to + * avoid resource conflicts with broken firmware that + * doesn't properly list 'stolen RAM' as a system region + * in the E820 map. + */ + for (u32 idx = 0; idx < e820_table->nr_entries; idx++) { + struct e820_entry *entry = &e820_table->entries[idx]; + u64 start, end; + + if (entry->type != E820_TYPE_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_info("e820: register RAM buffer resource [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: + */ +__init char * e820__memory_setup_default(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 + */ + 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__range_add(0, LOWMEMSIZE(), E820_TYPE_RAM); + e820__range_add(HIGH_MEMORY, mem_size << 10, E820_TYPE_RAM); + } + + /* We just appended a lot of ranges, sanitize the table: */ + e820__update_table(e820_table); + + 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: + */ +__init void e820__memory_setup(void) +{ + char *who; + + /* This is a firmware interface ABI - make sure we don't break it: */ + BUILD_BUG_ON(sizeof(struct boot_e820_entry) != 20); + + who = x86_init.resources.memory_setup(); + + memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec)); + memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware)); + + pr_info("BIOS-provided physical RAM map:\n"); + e820__print_table(who); +} + +__init void e820__memblock_setup(void) +{ + u32 idx; + u64 end; + +#ifdef CONFIG_MEMORY_HOTPLUG + /* + * Memory used by the kernel cannot be hot-removed because Linux + * cannot migrate the kernel pages. When memory hotplug is + * enabled, we should prevent memblock from allocating memory + * for the kernel. + * + * ACPI SRAT records all hotpluggable memory ranges. But before + * SRAT is parsed, we don't know about it. + * + * The kernel image is loaded into memory at very early time. We + * cannot prevent this anyway. So on NUMA system, we set any + * node the kernel resides in as un-hotpluggable. + * + * Since on modern servers, one node could have double-digit + * gigabytes memory, we can assume the memory around the kernel + * image is also un-hotpluggable. So before SRAT is parsed, just + * allocate memory near the kernel image to try the best to keep + * the kernel away from hotpluggable memory. + */ + if (movable_node_is_enabled()) + memblock_set_bottom_up(true); +#endif + + /* + * At this point only the first megabyte is mapped for sure, the + * rest of the memory cannot be used for memblock resizing + */ + memblock_set_current_limit(ISA_END_ADDRESS); + + /* + * 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 (idx = 0; idx < e820_table->nr_entries; idx++) { + struct e820_entry *entry = &e820_table->entries[idx]; + + end = entry->addr + entry->size; + if (end != (resource_size_t)end) + continue; + + if (entry->type == E820_TYPE_SOFT_RESERVED) + memblock_reserve(entry->addr, entry->size); + + if (entry->type != E820_TYPE_RAM) + continue; + + memblock_add(entry->addr, entry->size); + } + + /* + * At this point memblock is only allowed to allocate from memory + * below 1M (aka ISA_END_ADDRESS) up until direct map is completely set + * up in init_mem_mapping(). + * + * KHO kernels are special and use only scratch memory for memblock + * allocations, but memory below 1M is ignored by kernel after early + * boot and cannot be naturally marked as scratch. + * + * To allow allocation of the real-mode trampoline and a few (if any) + * other very early allocations from below 1M forcibly mark the memory + * below 1M as scratch. + * + * After real mode trampoline is allocated, we clear that scratch + * marking. + */ + memblock_mark_kho_scratch(0, SZ_1M); + + /* + * 32-bit systems are limited to 4BG of memory even with HIGHMEM and + * to even less without it. + * Discard memory after max_pfn - the actual limit detected at runtime. + */ + if (IS_ENABLED(CONFIG_X86_32)) + memblock_remove(PFN_PHYS(max_pfn), -1); + + /* Throw away partial pages: */ + memblock_trim_memory(PAGE_SIZE); + + memblock_dump_all(); +} |