x86: make e820.c to have common functions

remove the duplicated copy of these functions.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 475 insertions, 0 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
new file mode 100644
index 000000000000..2cb686f60d0d
--- /dev/null
+++ b/arch/x86/kernel/e820.c
@@ -0,0 +1,475 @@
+/*
+ * 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 <xela@slit.de>, December 2002.
+ *  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/ioport.h>
+#include <linux/string.h>
+#include <linux/kexec.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/pfn.h>
+
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/e820.h>
+#include <asm/setup.h>
+
+struct e820map e820;
+
+/* 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.
+ */
+int
+e820_any_mapped(u64 start, u64 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;
+}
+EXPORT_SYMBOL_GPL(e820_any_mapped);
+
+/*
+ * 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(u64 start, u64 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;
+        }
+        return 0;
+}
+
+/*
+ * Add a memory region to the kernel e820 map.
+ */
+void __init add_memory_region(u64 start, u64 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;
+
+        for (i = 0; i < e820.nr_map; i++) {
+                printk(KERN_INFO " %s: %016Lx - %016Lx ", who,
+                       (unsigned long long) e820.map[i].addr,
+                       (unsigned long long)
+                       (e820.map[i].addr + e820.map[i].size));
+                switch (e820.map[i].type) {
+                case E820_RAM:
+                        printk(KERN_CONT "(usable)\n");
+                        break;
+                case E820_RESERVED:
+                        printk(KERN_CONT "(reserved)\n");
+                        break;
+                case E820_ACPI:
+                        printk(KERN_CONT "(ACPI data)\n");
+                        break;
+                case E820_NVS:
+                        printk(KERN_CONT "(ACPI NVS)\n");
+                        break;
+                default:
+                        printk(KERN_CONT "type %u\n", e820.map[i].type);
+                        break;
+                }
+        }
+}
+
+/*
+ * Sanitize the BIOS e820 map.
+ *
+ * Some e820 responses include overlapping entries. The following
+ * replaces the original e820 map with a new one, removing overlaps.
+ *
+ */
+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++)  {
+                        unsigned long long curaddr, lastaddr;
+                        unsigned long long curpbaddr, lastpbaddr;
+
+                        curaddr = change_point[i]->addr;
+                        lastaddr = change_point[i - 1]->addr;
+                        curpbaddr = change_point[i]->pbios->addr;
+                        lastpbaddr = change_point[i - 1]->pbios->addr;
+
+                        /*
+                         * swap entries, when:
+                         *
+                         * curaddr > lastaddr or
+                         * curaddr == lastaddr and curaddr == curpbaddr and
+                         * lastaddr != lastpbaddr
+                         */
+                        if (curaddr < lastaddr ||
+                            (curaddr == lastaddr && curaddr == curpbaddr &&
+                             lastaddr != lastpbaddr)) {
+                                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)
+                                        /*
+                                         * no more space left for new
+                                         * bios entries ?
+                                         */
+                                        if (++new_bios_entry >= E820MAX)
+                                                break;
+                        }
+                        if (current_type != 0)  {
+                                new_bios[new_bios_entry].addr =
+                                        change_point[chgidx]->addr;
+                                new_bios[new_bios_entry].type = current_type;
+                                last_addr = change_point[chgidx]->addr;
+                        }
+                        last_type = current_type;
+                }
+        }
+        /* retain count for new bios entries */
+        new_nr = new_bios_entry;
+
+        /* copy new bios mapping into 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.
+ */
+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 {
+                u64 start = biosmap->addr;
+                u64 size = biosmap->size;
+                u64 end = start + size;
+                u32 type = biosmap->type;
+
+                /* Overflow in 64 bits? Ignore the memory map. */
+                if (start > end)
+                        return -1;
+
+                add_memory_region(start, size, type);
+        } while (biosmap++, --nr_map);
+        return 0;
+}
+
+u64 __init update_memory_range(u64 start, u64 size, unsigned old_type,
+                                unsigned new_type)
+{
+        int i;
+        u64 real_updated_size = 0;
+
+        BUG_ON(old_type == new_type);
+
+        for (i = 0; i < e820.nr_map; i++) {
+                struct e820entry *ei = &e820.map[i];
+                u64 final_start, final_end;
+                if (ei->type != old_type)
+                        continue;
+                /* totally covered? */
+                if (ei->addr >= start &&
+                    (ei->addr + ei->size) <= (start + size)) {
+                        ei->type = new_type;
+                        real_updated_size += ei->size;
+                        continue;
+                }
+                /* partially covered */
+                final_start = max(start, ei->addr);
+                final_end = min(start + size, ei->addr + ei->size);
+                if (final_start >= final_end)
+                        continue;
+                add_memory_region(final_start, final_end - final_start,
+                                         new_type);
+                real_updated_size += final_end - final_start;
+        }
+        return real_updated_size;
+}
+
+void __init update_e820(void)
+{
+        u8 nr_map;
+
+        nr_map = e820.nr_map;
+        if (sanitize_e820_map(e820.map, &nr_map))
+                return;
+        e820.nr_map = nr_map;
+        printk(KERN_INFO "modified physical RAM map:\n");
+        e820_print_map("modified");
+}
+
+/*
+ * 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 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;
+        }
+
+#ifdef CONFIG_X86_64
+        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");
+        }
+#endif
+
+        /*
+         * 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);
+}
+