mirror of https://gitee.com/openkylin/linux.git
585 lines
16 KiB
C
585 lines
16 KiB
C
/*
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* Handle the memory map.
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* The functions here do the job until bootmem takes over.
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* $Id: e820.c,v 1.4 2002/09/19 19:25:32 ak Exp $
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*
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* Getting sanitize_e820_map() in sync with i386 version by applying change:
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* - Provisions for empty E820 memory regions (reported by certain BIOSes).
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* Alex Achenbach <xela@slit.de>, December 2002.
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* Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
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*
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*/
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#include <linux/config.h>
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/bootmem.h>
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#include <linux/ioport.h>
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#include <linux/string.h>
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#include <linux/kexec.h>
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#include <asm/page.h>
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#include <asm/e820.h>
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#include <asm/proto.h>
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#include <asm/bootsetup.h>
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extern char _end[];
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/*
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* PFN of last memory page.
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*/
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unsigned long end_pfn;
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/*
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* end_pfn only includes RAM, while end_pfn_map includes all e820 entries.
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* The direct mapping extends to end_pfn_map, so that we can directly access
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* apertures, ACPI and other tables without having to play with fixmaps.
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*/
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unsigned long end_pfn_map;
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/*
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* Last pfn which the user wants to use.
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*/
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unsigned long end_user_pfn = MAXMEM>>PAGE_SHIFT;
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extern struct resource code_resource, data_resource;
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/* Check for some hardcoded bad areas that early boot is not allowed to touch */
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static inline int bad_addr(unsigned long *addrp, unsigned long size)
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{
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unsigned long addr = *addrp, last = addr + size;
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/* various gunk below that needed for SMP startup */
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if (addr < 0x8000) {
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*addrp = 0x8000;
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return 1;
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}
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/* direct mapping tables of the kernel */
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if (last >= table_start<<PAGE_SHIFT && addr < table_end<<PAGE_SHIFT) {
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*addrp = table_end << PAGE_SHIFT;
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return 1;
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}
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/* initrd */
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#ifdef CONFIG_BLK_DEV_INITRD
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if (LOADER_TYPE && INITRD_START && last >= INITRD_START &&
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addr < INITRD_START+INITRD_SIZE) {
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*addrp = INITRD_START + INITRD_SIZE;
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return 1;
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}
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#endif
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/* kernel code + 640k memory hole (later should not be needed, but
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be paranoid for now) */
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if (last >= 640*1024 && addr < __pa_symbol(&_end)) {
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*addrp = __pa_symbol(&_end);
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return 1;
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}
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/* XXX ramdisk image here? */
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return 0;
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}
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int __init e820_mapped(unsigned long start, unsigned long end, unsigned type)
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{
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int i;
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for (i = 0; i < e820.nr_map; i++) {
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struct e820entry *ei = &e820.map[i];
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if (type && ei->type != type)
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continue;
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if (ei->addr >= end || ei->addr + ei->size < start)
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continue;
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return 1;
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}
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return 0;
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}
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/*
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* Find a free area in a specific range.
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*/
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unsigned long __init find_e820_area(unsigned long start, unsigned long end, unsigned size)
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{
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int i;
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for (i = 0; i < e820.nr_map; i++) {
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struct e820entry *ei = &e820.map[i];
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unsigned long addr = ei->addr, last;
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if (ei->type != E820_RAM)
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continue;
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if (addr < start)
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addr = start;
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if (addr > ei->addr + ei->size)
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continue;
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while (bad_addr(&addr, size) && addr+size < ei->addr + ei->size)
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;
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last = addr + size;
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if (last > ei->addr + ei->size)
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continue;
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if (last > end)
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continue;
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return addr;
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}
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return -1UL;
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}
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/*
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* Free bootmem based on the e820 table for a node.
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*/
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void __init e820_bootmem_free(pg_data_t *pgdat, unsigned long start,unsigned long end)
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{
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int i;
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for (i = 0; i < e820.nr_map; i++) {
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struct e820entry *ei = &e820.map[i];
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unsigned long last, addr;
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if (ei->type != E820_RAM ||
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ei->addr+ei->size <= start ||
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ei->addr > end)
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continue;
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addr = round_up(ei->addr, PAGE_SIZE);
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if (addr < start)
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addr = start;
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last = round_down(ei->addr + ei->size, PAGE_SIZE);
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if (last >= end)
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last = end;
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if (last > addr && last-addr >= PAGE_SIZE)
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free_bootmem_node(pgdat, addr, last-addr);
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}
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}
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/*
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* Find the highest page frame number we have available
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*/
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unsigned long __init e820_end_of_ram(void)
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{
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int i;
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unsigned long end_pfn = 0;
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for (i = 0; i < e820.nr_map; i++) {
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struct e820entry *ei = &e820.map[i];
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unsigned long start, end;
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start = round_up(ei->addr, PAGE_SIZE);
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end = round_down(ei->addr + ei->size, PAGE_SIZE);
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if (start >= end)
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continue;
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if (ei->type == E820_RAM) {
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if (end > end_pfn<<PAGE_SHIFT)
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end_pfn = end>>PAGE_SHIFT;
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} else {
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if (end > end_pfn_map<<PAGE_SHIFT)
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end_pfn_map = end>>PAGE_SHIFT;
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}
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}
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if (end_pfn > end_pfn_map)
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end_pfn_map = end_pfn;
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if (end_pfn_map > MAXMEM>>PAGE_SHIFT)
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end_pfn_map = MAXMEM>>PAGE_SHIFT;
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if (end_pfn > end_user_pfn)
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end_pfn = end_user_pfn;
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if (end_pfn > end_pfn_map)
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end_pfn = end_pfn_map;
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return end_pfn;
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}
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/*
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* Mark e820 reserved areas as busy for the resource manager.
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*/
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void __init e820_reserve_resources(void)
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{
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int i;
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for (i = 0; i < e820.nr_map; i++) {
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struct resource *res;
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res = alloc_bootmem_low(sizeof(struct resource));
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switch (e820.map[i].type) {
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case E820_RAM: res->name = "System RAM"; break;
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case E820_ACPI: res->name = "ACPI Tables"; break;
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case E820_NVS: res->name = "ACPI Non-volatile Storage"; break;
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default: res->name = "reserved";
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}
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res->start = e820.map[i].addr;
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res->end = res->start + e820.map[i].size - 1;
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res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
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request_resource(&iomem_resource, res);
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if (e820.map[i].type == E820_RAM) {
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/*
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* We don't know which RAM region contains kernel data,
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* so we try it repeatedly and let the resource manager
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* test it.
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*/
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request_resource(res, &code_resource);
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request_resource(res, &data_resource);
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#ifdef CONFIG_KEXEC
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request_resource(res, &crashk_res);
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#endif
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}
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}
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}
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/*
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* Add a memory region to the kernel e820 map.
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*/
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void __init add_memory_region(unsigned long start, unsigned long size, int type)
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{
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int x = e820.nr_map;
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if (x == E820MAX) {
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printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
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return;
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}
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e820.map[x].addr = start;
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e820.map[x].size = size;
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e820.map[x].type = type;
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e820.nr_map++;
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}
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void __init e820_print_map(char *who)
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{
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int i;
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for (i = 0; i < e820.nr_map; i++) {
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printk(" %s: %016Lx - %016Lx ", who,
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(unsigned long long) e820.map[i].addr,
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(unsigned long long) (e820.map[i].addr + e820.map[i].size));
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switch (e820.map[i].type) {
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case E820_RAM: printk("(usable)\n");
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break;
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case E820_RESERVED:
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printk("(reserved)\n");
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break;
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case E820_ACPI:
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printk("(ACPI data)\n");
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break;
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case E820_NVS:
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printk("(ACPI NVS)\n");
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break;
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default: printk("type %u\n", e820.map[i].type);
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break;
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}
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}
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}
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/*
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* Sanitize the BIOS e820 map.
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*
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* Some e820 responses include overlapping entries. The following
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* replaces the original e820 map with a new one, removing overlaps.
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*
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*/
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static int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
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{
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struct change_member {
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struct e820entry *pbios; /* pointer to original bios entry */
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unsigned long long addr; /* address for this change point */
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};
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static struct change_member change_point_list[2*E820MAX] __initdata;
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static struct change_member *change_point[2*E820MAX] __initdata;
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static struct e820entry *overlap_list[E820MAX] __initdata;
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static struct e820entry new_bios[E820MAX] __initdata;
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struct change_member *change_tmp;
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unsigned long current_type, last_type;
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unsigned long long last_addr;
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int chgidx, still_changing;
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int overlap_entries;
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int new_bios_entry;
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int old_nr, new_nr, chg_nr;
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int i;
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/*
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Visually we're performing the following (1,2,3,4 = memory types)...
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Sample memory map (w/overlaps):
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____22__________________
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______________________4_
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____1111________________
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_44_____________________
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11111111________________
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____________________33__
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___________44___________
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__________33333_________
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______________22________
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___________________2222_
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_________111111111______
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_____________________11_
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_________________4______
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Sanitized equivalent (no overlap):
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1_______________________
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_44_____________________
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___1____________________
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____22__________________
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______11________________
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_________1______________
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__________3_____________
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___________44___________
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_____________33_________
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_______________2________
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________________1_______
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_________________4______
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___________________2____
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____________________33__
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______________________4_
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*/
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/* if there's only one memory region, don't bother */
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if (*pnr_map < 2)
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return -1;
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old_nr = *pnr_map;
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/* bail out if we find any unreasonable addresses in bios map */
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for (i=0; i<old_nr; i++)
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if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
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return -1;
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/* create pointers for initial change-point information (for sorting) */
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for (i=0; i < 2*old_nr; i++)
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change_point[i] = &change_point_list[i];
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/* record all known change-points (starting and ending addresses),
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omitting those that are for empty memory regions */
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chgidx = 0;
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for (i=0; i < old_nr; i++) {
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if (biosmap[i].size != 0) {
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change_point[chgidx]->addr = biosmap[i].addr;
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change_point[chgidx++]->pbios = &biosmap[i];
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change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
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change_point[chgidx++]->pbios = &biosmap[i];
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}
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}
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chg_nr = chgidx;
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/* sort change-point list by memory addresses (low -> high) */
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still_changing = 1;
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while (still_changing) {
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still_changing = 0;
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for (i=1; i < chg_nr; i++) {
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/* if <current_addr> > <last_addr>, swap */
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/* or, if current=<start_addr> & last=<end_addr>, swap */
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if ((change_point[i]->addr < change_point[i-1]->addr) ||
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((change_point[i]->addr == change_point[i-1]->addr) &&
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(change_point[i]->addr == change_point[i]->pbios->addr) &&
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(change_point[i-1]->addr != change_point[i-1]->pbios->addr))
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)
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{
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change_tmp = change_point[i];
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change_point[i] = change_point[i-1];
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change_point[i-1] = change_tmp;
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still_changing=1;
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}
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}
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}
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/* create a new bios memory map, removing overlaps */
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overlap_entries=0; /* number of entries in the overlap table */
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new_bios_entry=0; /* index for creating new bios map entries */
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last_type = 0; /* start with undefined memory type */
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last_addr = 0; /* start with 0 as last starting address */
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/* loop through change-points, determining affect on the new bios map */
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for (chgidx=0; chgidx < chg_nr; chgidx++)
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{
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/* keep track of all overlapping bios entries */
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if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
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{
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/* add map entry to overlap list (> 1 entry implies an overlap) */
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overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
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}
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else
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{
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/* remove entry from list (order independent, so swap with last) */
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for (i=0; i<overlap_entries; i++)
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{
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if (overlap_list[i] == change_point[chgidx]->pbios)
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overlap_list[i] = overlap_list[overlap_entries-1];
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}
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overlap_entries--;
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}
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/* if there are overlapping entries, decide which "type" to use */
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/* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
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current_type = 0;
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for (i=0; i<overlap_entries; i++)
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if (overlap_list[i]->type > current_type)
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current_type = overlap_list[i]->type;
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/* continue building up new bios map based on this information */
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if (current_type != last_type) {
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if (last_type != 0) {
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new_bios[new_bios_entry].size =
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change_point[chgidx]->addr - last_addr;
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/* move forward only if the new size was non-zero */
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if (new_bios[new_bios_entry].size != 0)
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if (++new_bios_entry >= E820MAX)
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break; /* no more space left for new bios entries */
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}
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if (current_type != 0) {
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new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
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new_bios[new_bios_entry].type = current_type;
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last_addr=change_point[chgidx]->addr;
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}
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last_type = current_type;
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}
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}
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new_nr = new_bios_entry; /* retain count for new bios entries */
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/* copy new bios mapping into original location */
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memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
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*pnr_map = new_nr;
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return 0;
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}
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/*
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* Copy the BIOS e820 map into a safe place.
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*
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* Sanity-check it while we're at it..
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*
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* If we're lucky and live on a modern system, the setup code
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* will have given us a memory map that we can use to properly
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* set up memory. If we aren't, we'll fake a memory map.
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*
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* We check to see that the memory map contains at least 2 elements
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* before we'll use it, because the detection code in setup.S may
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* not be perfect and most every PC known to man has two memory
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* regions: one from 0 to 640k, and one from 1mb up. (The IBM
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* thinkpad 560x, for example, does not cooperate with the memory
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* detection code.)
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*/
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static int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
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{
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/* Only one memory region (or negative)? Ignore it */
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if (nr_map < 2)
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return -1;
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do {
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unsigned long start = biosmap->addr;
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unsigned long size = biosmap->size;
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unsigned long end = start + size;
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unsigned long type = biosmap->type;
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/* Overflow in 64 bits? Ignore the memory map. */
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if (start > end)
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return -1;
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/*
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* Some BIOSes claim RAM in the 640k - 1M region.
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* Not right. Fix it up.
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*
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* This should be removed on Hammer which is supposed to not
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* have non e820 covered ISA mappings there, but I had some strange
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* problems so it stays for now. -AK
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*/
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if (type == E820_RAM) {
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if (start < 0x100000ULL && end > 0xA0000ULL) {
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if (start < 0xA0000ULL)
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add_memory_region(start, 0xA0000ULL-start, type);
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if (end <= 0x100000ULL)
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continue;
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start = 0x100000ULL;
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size = end - start;
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}
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}
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add_memory_region(start, size, type);
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} while (biosmap++,--nr_map);
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return 0;
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}
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void __init setup_memory_region(void)
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{
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char *who = "BIOS-e820";
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/*
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* Try to copy the BIOS-supplied E820-map.
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*
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* Otherwise fake a memory map; one section from 0k->640k,
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* the next section from 1mb->appropriate_mem_k
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*/
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sanitize_e820_map(E820_MAP, &E820_MAP_NR);
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if (copy_e820_map(E820_MAP, E820_MAP_NR) < 0) {
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unsigned long mem_size;
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/* compare results from other methods and take the greater */
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if (ALT_MEM_K < EXT_MEM_K) {
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mem_size = EXT_MEM_K;
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who = "BIOS-88";
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} else {
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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;
|
|
}
|
|
|
|
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;
|
|
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");
|
|
}
|
|
|
|
/*
|
|
* Start allocating dynamic PCI memory a bit into the gap,
|
|
* aligned up to the nearest megabyte.
|
|
*
|
|
* Question: should we try to pad it up a bit (do something
|
|
* like " + (gapsize >> 3)" in there too?). We now have the
|
|
* technology.
|
|
*/
|
|
pci_mem_start = (gapstart + 0xfffff) & ~0xfffff;
|
|
|
|
printk(KERN_INFO "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
|
|
pci_mem_start, gapstart, gapsize);
|
|
}
|