[PATCH] Increase number of e820 entries hard limit from 32 to 128

The specifications that talk about E820 map doesn't have an upper limit on
the number of e820 entries.  But, today's kernel has a hard limit of 32.
With increase in memory size, we are seeing the number of E820 entries
reaching close to 32.  Patch below bumps the number upto 128.

The patch changes the location of EDDBUF in zero-page (as it comes after E820).
As, EDDBUF is not used by boot loaders, this patch should not have any effect
on bootloader-setup code interface.

Patch covers both i386 and x86-64.

Tested on:
* grub booting bzImage
* lilo booting bzImage with EDID info enabled
* pxeboot of bzImage

Side-effect:
bss increases by ~ 2K and init.data increases by ~7.5K
on all systems, due to increase in size of static arrays.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 9 insertions, 10 deletions

diff --git a/arch/i386/boot/setup.S b/arch/i386/boot/setup.S
index a934ab32bf8e..caa1fde6904e 100644
--- a/arch/i386/boot/setup.S
+++ b/arch/i386/boot/setup.S
@@ -164,7 +164,7 @@ ramdisk_max:	.long (-__PAGE_OFFSET-(512 << 20)-1) & 0x7fffffff
 trampoline:     call    start_of_setup
                 .align 16
                                         # The offset at this point is 0x240
-                .space  (0x7ff-0x240+1) # E820 & EDD space (ending at 0x7ff)
+                .space  (0xeff-0x240+1) # E820 & EDD space (ending at 0xeff)
 # End of setup header #####################################################
 
 start_of_setup:
@@ -333,9 +333,9 @@ jmpe820:
         # sizeof(e820rec).
         #
 good820:
-        movb    (E820NR), %al                   # up to 32 entries
+        movb    (E820NR), %al                   # up to 128 entries
         cmpb    $E820MAX, %al
-        jnl     bail820
+        jae     bail820
 
         incb    (E820NR)
         movw    %di, %ax
diff --git a/arch/x86_64/boot/setup.S b/arch/x86_64/boot/setup.S
index 3e838be9dbe7..75d4d2ad93b3 100644
--- a/arch/x86_64/boot/setup.S
+++ b/arch/x86_64/boot/setup.S
@@ -160,7 +160,7 @@ ramdisk_max:	.long 0xffffffff
 trampoline:     call    start_of_setup
                 .align 16
                                         # The offset at this point is 0x240
-                .space  (0x7ff-0x240+1) # E820 & EDD space (ending at 0x7ff)
+                .space  (0xeff-0x240+1) # E820 & EDD space (ending at 0xeff)
 # End of setup header #####################################################
 
 start_of_setup:
@@ -412,9 +412,9 @@ jmpe820:
         # sizeof(e820rec).
         #
 good820:
-        movb    (E820NR), %al                   # up to 32 entries
+        movb    (E820NR), %al                   # up to 128 entries
         cmpb    $E820MAX, %al
-        jnl     bail820
+        jae     bail820
 
         incb    (E820NR)
         movw    %di, %ax
diff --git a/arch/x86_64/kernel/head64.c b/arch/x86_64/kernel/head64.c
index 6cad46c98a23..77df2ccb08f1 100644
--- a/arch/x86_64/kernel/head64.c
+++ b/arch/x86_64/kernel/head64.c
@@ -29,8 +29,6 @@ static void __init clear_bss(void)
                (unsigned long) __bss_end - (unsigned long) __bss_start);
 }
 
-extern char x86_boot_params[2048];
-
 #define NEW_CL_POINTER          0x228   /* Relative to real mode data */
 #define OLD_CL_MAGIC_ADDR       0x90020
 #define OLD_CL_MAGIC            0xA33F
@@ -44,7 +42,7 @@ static void __init copy_bootdata(char *real_mode_data)
         int new_data;
         char * command_line;
 
-        memcpy(x86_boot_params, real_mode_data, 2048); 
+        memcpy(x86_boot_params, real_mode_data, BOOT_PARAM_SIZE);
         new_data = *(int *) (x86_boot_params + NEW_CL_POINTER);
         if (!new_data) {
                 if (OLD_CL_MAGIC != * (u16 *) OLD_CL_MAGIC_ADDR) {
diff --git a/arch/x86_64/kernel/setup64.c b/arch/x86_64/kernel/setup64.c
index b5305b04bc40..678b7ac33b8b 100644
--- a/arch/x86_64/kernel/setup64.c
+++ b/arch/x86_64/kernel/setup64.c
@@ -12,6 +12,7 @@
 #include <linux/string.h>
 #include <linux/bootmem.h>
 #include <linux/bitops.h>
+#include <asm/bootsetup.h>
 #include <asm/pda.h>
 #include <asm/pgtable.h>
 #include <asm/processor.h>
@@ -26,7 +27,7 @@
 #include <asm/mman.h>
 #include <asm/numa.h>
 
-char x86_boot_params[2048] __initdata = {0,};
+char x86_boot_params[BOOT_PARAM_SIZE] __initdata = {0,};
 
 cpumask_t cpu_initialized __initdata = CPU_MASK_NONE;