[PATCH] x86: Make backtracer fallback logic more bullet-proof

[safe/jmp/linux-2.6] / arch / x86_64 / kernel / e820.c

diff --git a/arch/x86_64/kernel/e820.c b/arch/x86_64/kernel/e820.c
index b548dea..d81e3d6 100644 (file)
--- a/arch/x86_64/kernel/e820.c
+++ b/arch/x86_64/kernel/e820.c
@@ -1,7 +1,6 @@
 /* 
  * 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).
@@ -9,7 +8,6 @@
  *  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  *
  */
-#include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/init.h>
@@ -17,17 +15,20 @@
 #include <linux/ioport.h>
 #include <linux/string.h>
 #include <linux/kexec.h>
+#include <linux/module.h>
+
+#include <asm/pgtable.h>
 #include <asm/page.h>
 #include <asm/e820.h>
 #include <asm/proto.h>
 #include <asm/bootsetup.h>
-
-extern char _end[];
+#include <asm/sections.h>
 
 /* 
  * 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.
@@ -74,18 +75,29 @@ static inline int bad_addr(unsigned long *addrp, unsigned long size)
                *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;
 } 
 
-int __init e820_mapped(unsigned long start, unsigned long end, unsigned type) 
+/*
+ * This function checks if any part of the range <start,end> is mapped
+ * with type.
+ */
+int __meminit
+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) 
+               if (ei->addr >= end || ei->addr + ei->size <= start)
                        continue; 
                return 1; 
        } 
@@ -107,7 +119,7 @@ unsigned long __init find_e820_area(unsigned long start, unsigned long end, unsi
                        addr = start;
                if (addr > ei->addr + ei->size) 
                        continue; 
-               while (bad_addr(&addr, size) && addr+size < ei->addr + ei->size)
+               while (bad_addr(&addr, size) && addr+size <= ei->addr+ei->size)
                        ;
                last = addr + size;
                if (last > ei->addr + ei->size)
@@ -131,7 +143,7 @@ void __init e820_bootmem_free(pg_data_t *pgdat, unsigned long start,unsigned lon
 
                if (ei->type != E820_RAM || 
                    ei->addr+ei->size <= start || 
-                   ei->addr > end)
+                   ei->addr >= end)
                        continue;
 
                addr = round_up(ei->addr, PAGE_SIZE);
@@ -557,7 +569,29 @@ void __init parse_memopt(char *p, char **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;
+EXPORT_SYMBOL(pci_mem_start);
 
 /*
  * Search for the biggest gap in the low 32 bits of the e820
@@ -567,7 +601,7 @@ unsigned long pci_mem_start = 0xaeedbabe;
  */
 __init void e820_setup_gap(void)
 {
-       unsigned long gapstart, gapsize;
+       unsigned long gapstart, gapsize, round;
        unsigned long last;
        int i;
        int found = 0;
@@ -604,14 +638,14 @@ __init void e820_setup_gap(void)
        }
 
        /*
-        * 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.
+        * See how much we want to round up: start off with
+        * rounding to the next 1MB area.
         */
-       pci_mem_start = (gapstart + 0xfffff) & ~0xfffff;
+       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);