/* * 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 #include #include #include #include #include /* * PFN of last memory page. */ unsigned long end_pfn; /* * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries. * The direct mapping extends to max_pfn_mapped, so that we can directly access * apertures, ACPI and other tables without having to play with fixmaps. */ unsigned long max_pfn_mapped; /* * Last pfn which the user wants to use. */ static unsigned long __initdata end_user_pfn = MAXMEM>>PAGE_SHIFT; /* * Find the highest page frame number we have available */ unsigned long __init e820_end_of_ram(void) { unsigned long last_pfn; last_pfn = find_max_pfn_with_active_regions(); if (last_pfn > MAXMEM>>PAGE_SHIFT) last_pfn = MAXMEM>>PAGE_SHIFT; if (last_pfn > end_user_pfn) last_pfn = end_user_pfn; printk(KERN_INFO "last_pfn = %lu\n", last_pfn); return last_pfn; } /* * Mark e820 reserved areas as busy for the resource manager. */ void __init e820_reserve_resources(void) { int i; struct resource *res; res = alloc_bootmem_low(sizeof(struct resource) * e820.nr_map); for (i = 0; i < e820.nr_map; i++) { 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; insert_resource(&iomem_resource, res); res++; } } /* * Finds an active region in the address range from start_pfn to last_pfn and * returns its range in ei_startpfn and ei_endpfn for the e820 entry. */ static int __init e820_find_active_region(const struct e820entry *ei, unsigned long start_pfn, unsigned long last_pfn, unsigned long *ei_startpfn, unsigned long *ei_endpfn) { *ei_startpfn = round_up(ei->addr, PAGE_SIZE) >> PAGE_SHIFT; *ei_endpfn = round_down(ei->addr + ei->size, PAGE_SIZE) >> PAGE_SHIFT; /* Skip map entries smaller than a page */ if (*ei_startpfn >= *ei_endpfn) return 0; /* Skip if map is outside the node */ if (ei->type != E820_RAM || *ei_endpfn <= start_pfn || *ei_startpfn >= last_pfn) return 0; /* Check for overlaps */ if (*ei_startpfn < start_pfn) *ei_startpfn = start_pfn; if (*ei_endpfn > last_pfn) *ei_endpfn = last_pfn; /* Obey end_user_pfn to save on memmap */ if (*ei_startpfn >= end_user_pfn) return 0; if (*ei_endpfn > end_user_pfn) *ei_endpfn = end_user_pfn; return 1; } /* Walk the e820 map and register active regions within a node */ void __init e820_register_active_regions(int nid, unsigned long start_pfn, unsigned long last_pfn) { unsigned long ei_startpfn; unsigned long ei_endpfn; int i; for (i = 0; i < e820.nr_map; i++) if (e820_find_active_region(&e820.map[i], start_pfn, last_pfn, &ei_startpfn, &ei_endpfn)) add_active_range(nid, ei_startpfn, ei_endpfn); } /* * Find the hole size (in bytes) in the memory range. * @start: starting address of the memory range to scan * @end: ending address of the memory range to scan */ unsigned long __init e820_hole_size(unsigned long start, unsigned long end) { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long last_pfn = end >> PAGE_SHIFT; unsigned long ei_startpfn, ei_endpfn, ram = 0; int i; for (i = 0; i < e820.nr_map; i++) { if (e820_find_active_region(&e820.map[i], start_pfn, last_pfn, &ei_startpfn, &ei_endpfn)) ram += ei_endpfn - ei_startpfn; } return end - start - (ram << PAGE_SHIFT); } static void early_panic(char *msg) { early_printk(msg); panic(msg); } /* We're not void only for x86 32-bit compat */ char *__init machine_specific_memory_setup(void) { char *who = "BIOS-e820"; int 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_map(boot_params.e820_map, ARRAY_SIZE(boot_params.e820_map), &new_nr); boot_params.e820_entries = new_nr; if (copy_e820_map(boot_params.e820_map, boot_params.e820_entries) < 0) early_panic("Cannot find a valid memory map"); printk(KERN_INFO "BIOS-provided physical RAM map:\n"); e820_print_map(who); /* In case someone cares... */ return who; } static int __init parse_memopt(char *p) { if (!p) return -EINVAL; end_user_pfn = memparse(p, &p); end_user_pfn >>= PAGE_SHIFT; return 0; } early_param("mem", parse_memopt); static int userdef __initdata; static int __init parse_memmap_opt(char *p) { char *oldp; unsigned long long start_at, mem_size; if (!strcmp(p, "exactmap")) { #ifdef CONFIG_CRASH_DUMP /* * If we are doing a crash dump, we still need to know * the real mem size before original memory map is * reset. */ e820_register_active_regions(0, 0, -1UL); saved_max_pfn = e820_end_of_ram(); remove_all_active_ranges(); #endif e820.nr_map = 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); add_memory_region(start_at, mem_size, E820_RAM); } else if (*p == '#') { start_at = memparse(p+1, &p); add_memory_region(start_at, mem_size, E820_ACPI); } else if (*p == '$') { start_at = memparse(p+1, &p); add_memory_region(start_at, mem_size, E820_RESERVED); } else { end_user_pfn = (mem_size >> PAGE_SHIFT); } return *p == '\0' ? 0 : -EINVAL; } early_param("memmap", parse_memmap_opt); void __init finish_e820_parsing(void) { if (userdef) { int nr = e820.nr_map; if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0) early_panic("Invalid user supplied memory map"); e820.nr_map = nr; printk(KERN_INFO "user-defined physical RAM map:\n"); e820_print_map("user"); } } int __init arch_get_ram_range(int slot, u64 *addr, u64 *size) { int i; if (slot < 0 || slot >= e820.nr_map) return -1; for (i = slot; i < e820.nr_map; i++) { if (e820.map[i].type != E820_RAM) continue; break; } if (i == e820.nr_map || e820.map[i].addr > (max_pfn << PAGE_SHIFT)) return -1; *addr = e820.map[i].addr; *size = min_t(u64, e820.map[i].size + e820.map[i].addr, max_pfn << PAGE_SHIFT) - *addr; return i + 1; }