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authorH. Peter Anvin <hpa@zytor.com>2009-05-11 15:56:08 -0700
committerH. Peter Anvin <hpa@zytor.com>2009-05-11 17:44:39 -0700
commit37ba7ab5e33cebc25c68fffe33e9f21e7c2014e8 (patch)
tree006ba60fcd29b8fdee844ee6d90b85104a254d0d
parent99aa45595f45603526513d5e29fc00f8afbf3913 (diff)
downloadlinux-37ba7ab5e33cebc25c68fffe33e9f21e7c2014e8.tar.gz
x86, boot: make kernel_alignment adjustable; new bzImage fields
Make the kernel_alignment field adjustable; this allows us to set it to a large value (intended to be 16 MB to avoid ZONE_DMA contention, memory holes and other weirdness) while a smart bootloader can still force a loading at a lesser alignment if absolutely necessary. Also export pref_address (preferred loading address, corresponding to the link-time address) and init_size, the total amount of linear memory the kernel will require during initialization. [ Impact: allows better kernel placement, gives bootloader more info ] Signed-off-by: H. Peter Anvin <hpa@zytor.com>
-rw-r--r--arch/x86/boot/compressed/head_32.S7
-rw-r--r--arch/x86/boot/compressed/head_64.S14
-rw-r--r--arch/x86/boot/header.S15
-rw-r--r--arch/x86/include/asm/boot.h15
-rw-r--r--arch/x86/kernel/asm-offsets_32.c1
-rw-r--r--arch/x86/kernel/asm-offsets_64.c1
6 files changed, 45 insertions, 8 deletions
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index 2b8e0dfa4b27..75e4f001e706 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -69,8 +69,11 @@ ENTRY(startup_32)
#ifdef CONFIG_RELOCATABLE
movl %ebp, %ebx
- addl $(CONFIG_PHYSICAL_ALIGN - 1), %ebx
- andl $(~(CONFIG_PHYSICAL_ALIGN - 1)), %ebx
+ movl BP_kernel_alignment(%esi), %eax
+ decl %eax
+ addl %eax, %ebx
+ notl %eax
+ andl %eax, %ebx
#else
movl $LOAD_PHYSICAL_ADDR, %ebx
#endif
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 2bb500af1bd7..f62c284db9eb 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -84,8 +84,11 @@ ENTRY(startup_32)
#ifdef CONFIG_RELOCATABLE
movl %ebp, %ebx
- addl $(PMD_PAGE_SIZE -1), %ebx
- andl $PMD_PAGE_MASK, %ebx
+ movl BP_kernel_alignment(%esi), %eax
+ decl %eax
+ addl %eax, %ebx
+ notl %eax
+ andl %eax, %ebx
#else
movl $LOAD_PHYSICAL_ADDR, %ebx
#endif
@@ -224,8 +227,11 @@ ENTRY(startup_64)
/* Start with the delta to where the kernel will run at. */
#ifdef CONFIG_RELOCATABLE
leaq startup_32(%rip) /* - $startup_32 */, %rbp
- addq $(PMD_PAGE_SIZE - 1), %rbp
- andq $PMD_PAGE_MASK, %rbp
+ movl BP_kernel_alignment(%rsi), %eax
+ decl %eax
+ addq %rax, %rbp
+ notq %rax
+ andq %rax, %rbp
#else
movq $LOAD_PHYSICAL_ADDR, %rbp
#endif
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 27285143adeb..a0b426978d55 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -116,7 +116,7 @@ _start:
# Part 2 of the header, from the old setup.S
.ascii "HdrS" # header signature
- .word 0x0209 # header version number (>= 0x0105)
+ .word 0x020a # header version number (>= 0x0105)
# or else old loadlin-1.5 will fail)
.globl realmode_swtch
realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
@@ -201,7 +201,7 @@ relocatable_kernel: .byte 1
#else
relocatable_kernel: .byte 0
#endif
-pad2: .byte 0
+min_alignment: .byte MIN_KERNEL_ALIGN_LG2 # minimum alignment
pad3: .word 0
cmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line,
@@ -220,6 +220,17 @@ setup_data: .quad 0 # 64-bit physical pointer to
# single linked list of
# struct setup_data
+pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr
+
+#define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_extract_offset)
+#define VO_INIT_SIZE (VO__end - VO__text)
+#if ZO_INIT_SIZE > VO_INIT_SIZE
+#define INIT_SIZE ZO_INIT_SIZE
+#else
+#define INIT_SIZE VO_INIT_SIZE
+#endif
+init_size: .long INIT_SIZE # kernel initialization size
+
# End of setup header #####################################################
.section ".inittext", "ax"
diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
index 6ba23dd9fc92..418e632d4a80 100644
--- a/arch/x86/include/asm/boot.h
+++ b/arch/x86/include/asm/boot.h
@@ -8,11 +8,26 @@
#ifdef __KERNEL__
+#include <asm/page_types.h>
+
/* Physical address where kernel should be loaded. */
#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
+ (CONFIG_PHYSICAL_ALIGN - 1)) \
& ~(CONFIG_PHYSICAL_ALIGN - 1))
+/* Minimum kernel alignment, as a power of two */
+#ifdef CONFIG_x86_64
+#define MIN_KERNEL_ALIGN_LG2 PMD_SHIFT
+#else
+#define MIN_KERNEL_ALIGN_LG2 (PAGE_SHIFT+1)
+#endif
+#define MIN_KERNEL_ALIGN (_AC(1, UL) << MIN_KERNEL_ALIGN_LG2)
+
+#if (CONFIG_PHYSICAL_ALIGN & (CONFIG_PHYSICAL_ALIGN-1)) || \
+ (CONFIG_PHYSICAL_ALIGN < (_AC(1, UL) << MIN_KERNEL_ALIGN_LG2))
+#error "Invalid value for CONFIG_PHYSICAL_ALIGN"
+#endif
+
#ifdef CONFIG_KERNEL_BZIP2
#define BOOT_HEAP_SIZE 0x400000
#else /* !CONFIG_KERNEL_BZIP2 */
diff --git a/arch/x86/kernel/asm-offsets_32.c b/arch/x86/kernel/asm-offsets_32.c
index 5a6aa1c1162f..1a830cbd7015 100644
--- a/arch/x86/kernel/asm-offsets_32.c
+++ b/arch/x86/kernel/asm-offsets_32.c
@@ -146,4 +146,5 @@ void foo(void)
OFFSET(BP_loadflags, boot_params, hdr.loadflags);
OFFSET(BP_hardware_subarch, boot_params, hdr.hardware_subarch);
OFFSET(BP_version, boot_params, hdr.version);
+ OFFSET(BP_kernel_alignment, boot_params, hdr.kernel_alignment);
}
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index e72f062fb4b5..898ecc47e129 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -125,6 +125,7 @@ int main(void)
OFFSET(BP_loadflags, boot_params, hdr.loadflags);
OFFSET(BP_hardware_subarch, boot_params, hdr.hardware_subarch);
OFFSET(BP_version, boot_params, hdr.version);
+ OFFSET(BP_kernel_alignment, boot_params, hdr.kernel_alignment);
BLANK();
DEFINE(PAGE_SIZE_asm, PAGE_SIZE);