--- /dev/null
+/*
+ * Handle the memory map.
+ * The functions here do the job until bootmem takes over.
+ * $Id: e820.c,v 1.4 2002/09/19 19:25:32 ak Exp $
+ *
+ * Getting sanitize_e820_map() in sync with i386 version by applying change:
+ * - Provisions for empty E820 memory regions (reported by certain BIOSes).
+ * Alex Achenbach <xela@slit.de>, December 2002.
+ * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ *
+ */
+#include <lwk/kernel.h>
+#include <lwk/types.h>
+#include <lwk/init.h>
+#include <lwk/bootmem.h>
+#include <lwk/resource.h>
+#include <lwk/string.h>
+#include <lwk/linux_compat.h>
+
+#include <arch/page.h>
+#include <arch/pgtable.h>
+#include <arch/e820.h>
+#include <arch/proto.h>
+#include <arch/bootsetup.h>
+#include <arch/sections.h>
+
+/**
+ * The BIOS "e820" map of memory.
+ */
+struct e820map e820;
+
+/*
+ * PFN of last memory page.
+ */
+unsigned long end_pfn;
+EXPORT_SYMBOL(end_pfn);
+
+/*
+ * end_pfn only includes RAM, while end_pfn_map includes all e820 entries.
+ * The direct mapping extends to end_pfn_map, so that we can directly access
+ * apertures, ACPI and other tables without having to play with fixmaps.
+ */
+unsigned long end_pfn_map;
+
+/*
+ * Last pfn which the user wants to use.
+ */
+unsigned long end_user_pfn = MAXMEM>>PAGE_SHIFT;
+
+extern struct resource code_resource, data_resource;
+
+/* Check for some hardcoded bad areas that early boot is not allowed to touch */
+static inline int bad_addr(unsigned long *addrp, unsigned long size)
+{
+ unsigned long addr = *addrp, last = addr + size;
+
+ /* various gunk below that needed for SMP startup */
+ if (addr < 0x8000) {
+ *addrp = 0x8000;
+ return 1;
+ }
+
+ /* direct mapping tables of the kernel */
+ if (last >= table_start<<PAGE_SHIFT && addr < table_end<<PAGE_SHIFT) {
+ *addrp = table_end << PAGE_SHIFT;
+ return 1;
+ }
+
+ /* initrd image */
+ if (LOADER_TYPE && INITRD_START && last >= INITRD_START &&
+ addr < INITRD_START+INITRD_SIZE) {
+ *addrp = INITRD_START + INITRD_SIZE;
+ return 1;
+ }
+
+ /* kernel code + 640k memory hole (later should not be needed, but
+ be paranoid for now) */
+ if (last >= 640*1024 && addr < __pa_symbol(&_end)) {
+ *addrp = __pa_symbol(&_end);
+ return 1;
+ }
+
+ if (last >= ebda_addr && addr < ebda_addr + ebda_size) {
+ *addrp = ebda_addr + ebda_size;
+ return 1;
+ }
+
+ /* XXX ramdisk image here? */
+ return 0;
+}
+
+/*
+ * This function checks if any part of the range <start,end> is mapped
+ * with type.
+ */
+int __init
+e820_any_mapped(unsigned long start, unsigned long end, unsigned type)
+{
+ int i;
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+ if (type && ei->type != type)
+ continue;
+ if (ei->addr >= end || ei->addr + ei->size <= start)
+ continue;
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * This function checks if the entire range <start,end> is mapped with type.
+ *
+ * Note: this function only works correct if the e820 table is sorted and
+ * not-overlapping, which is the case
+ */
+int __init e820_all_mapped(unsigned long start, unsigned long end, unsigned type)
+{
+ int i;
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+ if (type && ei->type != type)
+ continue;
+ /* is the region (part) in overlap with the current region ?*/
+ if (ei->addr >= end || ei->addr + ei->size <= start)
+ continue;
+
+ /* if the region is at the beginning of <start,end> we move
+ * start to the end of the region since it's ok until there
+ */
+ if (ei->addr <= start)
+ start = ei->addr + ei->size;
+ /* if start is now at or beyond end, we're done, full coverage */
+ if (start >= end)
+ return 1; /* we're done */
+ }
+ return 0;
+}
+
+/*
+ * Find a free area in a specific range.
+ */
+unsigned long __init find_e820_area(unsigned long start, unsigned long end, unsigned size)
+{
+ int i;
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+ unsigned long addr = ei->addr, last;
+ if (ei->type != E820_RAM)
+ continue;
+ if (addr < start)
+ addr = start;
+ if (addr > ei->addr + ei->size)
+ continue;
+ while (bad_addr(&addr, size) && addr+size <= ei->addr+ei->size)
+ ;
+ last = addr + size;
+ if (last > ei->addr + ei->size)
+ continue;
+ if (last > end)
+ continue;
+ return addr;
+ }
+ return -1UL;
+}
+
+/*
+ * Free bootmem based on the e820 table for a node.
+ */
+void __init e820_bootmem_free(unsigned long start, unsigned long end)
+{
+ int i;
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+ unsigned long last, addr;
+
+ if (ei->type != E820_RAM ||
+ ei->addr+ei->size <= start ||
+ ei->addr >= end)
+ continue;
+
+ addr = round_up(ei->addr, PAGE_SIZE);
+ if (addr < start)
+ addr = start;
+
+ last = round_down(ei->addr + ei->size, PAGE_SIZE);
+ if (last >= end)
+ last = end;
+
+ if (last > addr && last-addr >= PAGE_SIZE)
+ free_bootmem(addr, last-addr);
+ }
+}
+
+/*
+ * Find the highest page frame number we have available
+ */
+unsigned long __init e820_end_of_ram(void)
+{
+ int i;
+ unsigned long end_pfn = 0;
+
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+ unsigned long start, end;
+
+ start = round_up(ei->addr, PAGE_SIZE);
+ end = round_down(ei->addr + ei->size, PAGE_SIZE);
+ if (start >= end)
+ continue;
+ if (ei->type == E820_RAM) {
+ if (end > end_pfn<<PAGE_SHIFT)
+ end_pfn = end>>PAGE_SHIFT;
+ } else {
+ if (end > end_pfn_map<<PAGE_SHIFT)
+ end_pfn_map = end>>PAGE_SHIFT;
+ }
+ }
+
+ if (end_pfn > end_pfn_map)
+ end_pfn_map = end_pfn;
+ if (end_pfn_map > MAXMEM>>PAGE_SHIFT)
+ end_pfn_map = MAXMEM>>PAGE_SHIFT;
+ if (end_pfn > end_user_pfn)
+ end_pfn = end_user_pfn;
+ if (end_pfn > end_pfn_map)
+ end_pfn = end_pfn_map;
+
+ return end_pfn;
+}
+
+/*
+ * Compute how much memory is missing in a range.
+ * Unlike the other functions in this file the arguments are in page numbers.
+ */
+unsigned long __init
+e820_hole_size(unsigned long start_pfn, unsigned long end_pfn)
+{
+ unsigned long ram = 0;
+ unsigned long start = start_pfn << PAGE_SHIFT;
+ unsigned long end = end_pfn << PAGE_SHIFT;
+ int i;
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+ unsigned long last, addr;
+
+ if (ei->type != E820_RAM ||
+ ei->addr+ei->size <= start ||
+ ei->addr >= end)
+ continue;
+
+ addr = round_up(ei->addr, PAGE_SIZE);
+ if (addr < start)
+ addr = start;
+
+ last = round_down(ei->addr + ei->size, PAGE_SIZE);
+ if (last >= end)
+ last = end;
+
+ if (last > addr)
+ ram += last - addr;
+ }
+ return ((end - start) - ram) >> PAGE_SHIFT;
+}
+
+/*
+ * Mark e820 reserved areas as busy for the resource manager.
+ */
+void __init e820_reserve_resources(void)
+{
+ int i;
+ for (i = 0; i < e820.nr_map; i++) {
+ struct resource *res;
+ res = alloc_bootmem(sizeof(struct resource));
+ 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;
+ request_resource(&iomem_resource, res);
+ if (e820.map[i].type == E820_RAM) {
+ /*
+ * We don't know which RAM region contains kernel data,
+ * so we try it repeatedly and let the resource manager
+ * test it.
+ */
+ request_resource(res, &code_resource);
+ request_resource(res, &data_resource);
+#ifdef CONFIG_KEXEC
+ request_resource(res, &crashk_res);
+#endif
+ }
+ }
+}
+
+/*
+ * Add a memory region to the kernel e820 map.
+ */
+void __init add_memory_region(unsigned long start, unsigned long size, int type)
+{
+ int x = e820.nr_map;
+
+ if (x == E820MAX) {
+ printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
+ return;
+ }
+
+ e820.map[x].addr = start;
+ e820.map[x].size = size;
+ e820.map[x].type = type;
+ e820.nr_map++;
+}
+
+void __init e820_print_map(char *who)
+{
+ int i;
+ char type[16];
+ size_t total_size = 0;
+
+ for (i = 0; i < e820.nr_map; i++) {
+ const struct e820entry * entry = &e820.map[i];
+ switch (entry->type) {
+ case E820_RAM: sprintf(type, "(usable)\n");
+ total_size += entry->size;
+ break;
+ case E820_RESERVED:
+ sprintf(type, "(reserved)\n");
+ break;
+ case E820_ACPI:
+ sprintf(type, "(ACPI data)\n");
+ break;
+ case E820_NVS:
+ sprintf(type, "(ACPI NVS)\n");
+ break;
+ default: sprintf(type, "type %u\n", entry->type);
+ break;
+ }
+
+ printk(KERN_DEBUG
+ " %s: %016Lx - %016Lx %s",
+ who,
+ (unsigned long long) entry->addr,
+ (unsigned long long) (entry->addr + entry->size),
+ type);
+ }
+
+ printk( KERN_DEBUG "Total usable memory %ld bytes\n", total_size );
+}
+
+/*
+ * Sanitize the BIOS e820 map.
+ *
+ * Some e820 responses include overlapping entries. The following
+ * replaces the original e820 map with a new one, removing overlaps.
+ *
+ */
+static int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
+{
+ struct change_member {
+ struct e820entry *pbios; /* pointer to original bios entry */
+ unsigned long long addr; /* address for this change point */
+ };
+ static struct change_member change_point_list[2*E820MAX] __initdata;
+ static struct change_member *change_point[2*E820MAX] __initdata;
+ static struct e820entry *overlap_list[E820MAX] __initdata;
+ static struct e820entry new_bios[E820MAX] __initdata;
+ struct change_member *change_tmp;
+ unsigned long current_type, last_type;
+ unsigned long long last_addr;
+ int chgidx, still_changing;
+ int overlap_entries;
+ int new_bios_entry;
+ int old_nr, new_nr, chg_nr;
+ int i;
+
+ /*
+ Visually we're performing the following (1,2,3,4 = memory types)...
+
+ Sample memory map (w/overlaps):
+ ____22__________________
+ ______________________4_
+ ____1111________________
+ _44_____________________
+ 11111111________________
+ ____________________33__
+ ___________44___________
+ __________33333_________
+ ______________22________
+ ___________________2222_
+ _________111111111______
+ _____________________11_
+ _________________4______
+
+ Sanitized equivalent (no overlap):
+ 1_______________________
+ _44_____________________
+ ___1____________________
+ ____22__________________
+ ______11________________
+ _________1______________
+ __________3_____________
+ ___________44___________
+ _____________33_________
+ _______________2________
+ ________________1_______
+ _________________4______
+ ___________________2____
+ ____________________33__
+ ______________________4_
+ */
+
+ /* if there's only one memory region, don't bother */
+ if (*pnr_map < 2)
+ return -1;
+
+ old_nr = *pnr_map;
+
+ /* bail out if we find any unreasonable addresses in bios map */
+ for (i=0; i<old_nr; i++)
+ if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
+ return -1;
+
+ /* create pointers for initial change-point information (for sorting) */
+ for (i=0; i < 2*old_nr; i++)
+ change_point[i] = &change_point_list[i];
+
+ /* record all known change-points (starting and ending addresses),
+ omitting those that are for empty memory regions */
+ chgidx = 0;
+ for (i=0; i < old_nr; i++) {
+ if (biosmap[i].size != 0) {
+ change_point[chgidx]->addr = biosmap[i].addr;
+ change_point[chgidx++]->pbios = &biosmap[i];
+ change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
+ change_point[chgidx++]->pbios = &biosmap[i];
+ }
+ }
+ chg_nr = chgidx;
+
+ /* sort change-point list by memory addresses (low -> high) */
+ still_changing = 1;
+ while (still_changing) {
+ still_changing = 0;
+ for (i=1; i < chg_nr; i++) {
+ /* if <current_addr> > <last_addr>, swap */
+ /* or, if current=<start_addr> & last=<end_addr>, swap */
+ if ((change_point[i]->addr < change_point[i-1]->addr) ||
+ ((change_point[i]->addr == change_point[i-1]->addr) &&
+ (change_point[i]->addr == change_point[i]->pbios->addr) &&
+ (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
+ )
+ {
+ change_tmp = change_point[i];
+ change_point[i] = change_point[i-1];
+ change_point[i-1] = change_tmp;
+ still_changing=1;
+ }
+ }
+ }
+
+ /* create a new bios memory map, removing overlaps */
+ overlap_entries=0; /* number of entries in the overlap table */
+ new_bios_entry=0; /* index for creating new bios map entries */
+ last_type = 0; /* start with undefined memory type */
+ last_addr = 0; /* start with 0 as last starting address */
+ /* loop through change-points, determining affect on the new bios map */
+ for (chgidx=0; chgidx < chg_nr; chgidx++)
+ {
+ /* keep track of all overlapping bios entries */
+ if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
+ {
+ /* add map entry to overlap list (> 1 entry implies an overlap) */
+ overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
+ }
+ else
+ {
+ /* remove entry from list (order independent, so swap with last) */
+ for (i=0; i<overlap_entries; i++)
+ {
+ if (overlap_list[i] == change_point[chgidx]->pbios)
+ overlap_list[i] = overlap_list[overlap_entries-1];
+ }
+ overlap_entries--;
+ }
+ /* if there are overlapping entries, decide which "type" to use */
+ /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
+ current_type = 0;
+ for (i=0; i<overlap_entries; i++)
+ if (overlap_list[i]->type > current_type)
+ current_type = overlap_list[i]->type;
+ /* continue building up new bios map based on this information */
+ if (current_type != last_type) {
+ if (last_type != 0) {
+ new_bios[new_bios_entry].size =
+ change_point[chgidx]->addr - last_addr;
+ /* move forward only if the new size was non-zero */
+ if (new_bios[new_bios_entry].size != 0)
+ if (++new_bios_entry >= E820MAX)
+ break; /* no more space left for new bios entries */
+ }
+ 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;
+ }
+ }
+ new_nr = new_bios_entry; /* retain count for new bios entries */
+
+ /* copy new bios mapping into original location */
+ memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
+ *pnr_map = new_nr;
+
+ return 0;
+}
+
+/*
+ * Copy the BIOS e820 map into a safe place.
+ *
+ * Sanity-check it while we're at it..
+ *
+ * If we're lucky and live on a modern system, the setup code
+ * will have given us a memory map that we can use to properly
+ * set up memory. If we aren't, we'll fake a memory map.
+ *
+ * We check to see that the memory map contains at least 2 elements
+ * before we'll use it, because the detection code in setup.S may
+ * not be perfect and most every PC known to man has two memory
+ * regions: one from 0 to 640k, and one from 1mb up. (The IBM
+ * thinkpad 560x, for example, does not cooperate with the memory
+ * detection code.)
+ */
+static int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
+{
+ /* Only one memory region (or negative)? Ignore it */
+ if (nr_map < 2)
+ return -1;
+
+ do {
+ unsigned long start = biosmap->addr;
+ unsigned long size = biosmap->size;
+ unsigned long end = start + size;
+ unsigned long type = biosmap->type;
+
+ /* Overflow in 64 bits? Ignore the memory map. */
+ if (start > end)
+ return -1;
+
+ /*
+ * Some BIOSes claim RAM in the 640k - 1M region.
+ * Not right. Fix it up.
+ *
+ * This should be removed on Hammer which is supposed to not
+ * have non e820 covered ISA mappings there, but I had some strange
+ * problems so it stays for now. -AK
+ */
+ if (type == E820_RAM) {
+ if (start < 0x100000ULL && end > 0xA0000ULL) {
+ if (start < 0xA0000ULL)
+ add_memory_region(start, 0xA0000ULL-start, type);
+ if (end <= 0x100000ULL)
+ continue;
+ start = 0x100000ULL;
+ size = end - start;
+ }
+ }
+
+ add_memory_region(start, size, type);
+ } while (biosmap++,--nr_map);
+ return 0;
+}
+
+void __init setup_memory_region(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
+ */
+ sanitize_e820_map(E820_MAP, &E820_MAP_NR);
+ if (copy_e820_map(E820_MAP, E820_MAP_NR) < 0) {
+ unsigned long mem_size;
+
+ /* compare results from other methods and take the greater */
+ if (ALT_MEM_K < EXT_MEM_K) {
+ mem_size = EXT_MEM_K;
+ who = "BIOS-88";
+ } else {
+ 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_DEBUG "BIOS-provided physical RAM map:\n");
+ e820_print_map(who);
+
+ /* This also sets end_pfn_map */
+ end_pfn = e820_end_of_ram();
+}
+
+void __init parse_memopt(char *p, char **from)
+{
+ end_user_pfn = memparse(p, from);
+ end_user_pfn >>= PAGE_SHIFT;
+}
+
+void __init parse_memmapopt(char *p, char **from)
+{
+ unsigned long long start_at, mem_size;
+
+ mem_size = memparse(p, from);
+ p = *from;
+ if (*p == '@') {
+ start_at = memparse(p+1, from);
+ add_memory_region(start_at, mem_size, E820_RAM);
+ } else if (*p == '#') {
+ start_at = memparse(p+1, from);
+ add_memory_region(start_at, mem_size, E820_ACPI);
+ } else if (*p == '$') {
+ start_at = memparse(p+1, from);
+ add_memory_region(start_at, mem_size, E820_RESERVED);
+ } else {
+ end_user_pfn = (mem_size >> PAGE_SHIFT);
+ }
+ p = *from;
+}
+
+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, round;
+ 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");
+ }
+
+ /*
+ * See how much we want to round up: start off with
+ * rounding to the next 1MB area.
+ */
+ round = 0x100000;
+ while ((gapsize >> 4) > round)
+ round += round;
+ /* Fun with two's complement */
+ pci_mem_start = (gapstart + round) & -round;
+
+ printk(KERN_INFO "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
+ pci_mem_start, gapstart, gapsize);
+}
