[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>

diff --git a/Documentation/i386/zero-page.txt b/Documentation/i386/zero-page.txt
index 67c053a..df28c74 100644 (file)
--- a/Documentation/i386/zero-page.txt
+++ b/Documentation/i386/zero-page.txt
@@ -79,6 +79,6 @@ Offset        Type            Description
 0x22c   unsigned long  ramdisk_max
 0x230   16 bytes       trampoline
 0x290 - 0x2cf          EDD_MBR_SIG_BUFFER (edd.S)
-0x2d0 - 0x600          E820MAP
-0x600 - 0x7ff          EDDBUF (edd.S) for disk signature read sector
-0x600 - 0x7eb          EDDBUF (edd.S) for edd data
+0x2d0 - 0xd00          E820MAP
+0xd00 - 0xeff          EDDBUF (edd.S) for disk signature read sector
+0xd00 - 0xeeb          EDDBUF (edd.S) for edd data

diff --git a/arch/i386/boot/setup.S b/arch/i386/boot/setup.S
index a934ab3..caa1fde 100644 (file)
--- 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 3e838be..75d4d2a 100644 (file)
--- 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 6cad46c..77df2cc 100644 (file)
--- 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 b5305b0..678b7ac 100644 (file)
--- 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;
 

diff --git a/include/asm-i386/e820.h b/include/asm-i386/e820.h
index 5c285ae..edf65be 100644 (file)
--- a/include/asm-i386/e820.h
+++ b/include/asm-i386/e820.h
@@ -13,7 +13,7 @@
 #define __E820_HEADER
 
 #define E820MAP        0x2d0           /* our map */
-#define E820MAX        32              /* number of entries in E820MAP */
+#define E820MAX        128             /* number of entries in E820MAP */
 #define E820NR 0x1e8           /* # entries in E820MAP */
 
 #define E820_RAM       1

diff --git a/include/asm-i386/setup.h b/include/asm-i386/setup.h
index 8814b54..7a32184 100644 (file)
--- a/include/asm-i386/setup.h
+++ b/include/asm-i386/setup.h
@@ -16,7 +16,7 @@
 #define MAXMEM_PFN     PFN_DOWN(MAXMEM)
 #define MAX_NONPAE_PFN (1 << 20)
 
-#define PARAM_SIZE 2048
+#define PARAM_SIZE 4096
 #define COMMAND_LINE_SIZE 256
 
 #define OLD_CL_MAGIC_ADDR      0x90020

diff --git a/include/asm-x86_64/bootsetup.h b/include/asm-x86_64/bootsetup.h
index b570a48..b829f7b 100644 (file)
--- a/include/asm-x86_64/bootsetup.h
+++ b/include/asm-x86_64/bootsetup.h
@@ -2,7 +2,8 @@
 #ifndef _X86_64_BOOTSETUP_H
 #define _X86_64_BOOTSETUP_H 1
 
-extern char x86_boot_params[2048];
+#define BOOT_PARAM_SIZE                4096
+extern char x86_boot_params[BOOT_PARAM_SIZE];
 
 /*
  * This is set up by the setup-routine at boot-time

diff --git a/include/asm-x86_64/e820.h b/include/asm-x86_64/e820.h
index 08f83a4..8e94edf 100644 (file)
--- a/include/asm-x86_64/e820.h
+++ b/include/asm-x86_64/e820.h
@@ -14,7 +14,7 @@
 #include <linux/mmzone.h>
 
 #define E820MAP        0x2d0           /* our map */
-#define E820MAX        32              /* number of entries in E820MAP */
+#define E820MAX        128             /* number of entries in E820MAP */
 #define E820NR 0x1e8           /* # entries in E820MAP */
 
 #define E820_RAM       1

diff --git a/include/linux/edd.h b/include/linux/edd.h
index c6e6747..162512b 100644 (file)
--- a/include/linux/edd.h
+++ b/include/linux/edd.h
@@ -32,7 +32,7 @@
 
 #define EDDNR 0x1e9            /* addr of number of edd_info structs at EDDBUF
                                   in boot_params - treat this as 1 byte  */
-#define EDDBUF 0x600           /* addr of edd_info structs in boot_params */
+#define EDDBUF 0xd00           /* addr of edd_info structs in boot_params */
 #define EDDMAXNR 6             /* number of edd_info structs starting at EDDBUF  */
 #define EDDEXTSIZE 8           /* change these if you muck with the structures */
 #define EDDPARMSIZE 74