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[PATCH] x86_64: miscellaneous cleanup
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- adjust limits of GDT/IDT pseudo-descriptors (some were off by one)
- move empty_zero_page into .bss.page_aligned
- move cpu_gdt_table into .data.page_aligned
- move idt_table into .bss
- align inital_code and init_rsp
- eliminate pointless (re-)declaration of idt_table in traps.c

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Jan Beulich authored and Linus Torvalds committed Mar 25, 2006
1 parent 1f50249 commit e57113b
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Showing 3 changed files with 15 additions and 14 deletions.
25 changes: 14 additions & 11 deletions arch/x86_64/kernel/head.S
Original file line number Diff line number Diff line change
Expand Up @@ -192,7 +192,8 @@ startup_64:
movq initial_code(%rip),%rax
jmp *%rax

/* SMP bootup changes these two */
/* SMP bootup changes these two */
.align 8
.globl initial_code
initial_code:
.quad x86_64_start_kernel
Expand Down Expand Up @@ -237,7 +238,7 @@ ENTRY(no_long_mode)
.org 0xf00
.globl pGDT32
pGDT32:
.word gdt_end-cpu_gdt_table
.word gdt_end-cpu_gdt_table-1
.long cpu_gdt_table-__START_KERNEL_map

.org 0xf10
Expand Down Expand Up @@ -293,8 +294,6 @@ NEXT_PAGE(level2_kernel_pgt)
/* Module mapping starts here */
.fill 492,8,0

NEXT_PAGE(empty_zero_page)

NEXT_PAGE(level3_physmem_pgt)
.quad phys_level2_kernel_pgt | 0x007 /* so that __va works even before pagetable_init */
.fill 511,8,0
Expand Down Expand Up @@ -337,7 +336,7 @@ ENTRY(boot_level4_pgt)
.align 16
.globl cpu_gdt_descr
cpu_gdt_descr:
.word gdt_end-cpu_gdt_table
.word gdt_end-cpu_gdt_table-1
gdt:
.quad cpu_gdt_table
#ifdef CONFIG_SMP
Expand All @@ -352,7 +351,8 @@ gdt:
* Also sysret mandates a special GDT layout
*/

.align PAGE_SIZE
.section .data.page_aligned, "aw"
.align PAGE_SIZE

/* The TLS descriptors are currently at a different place compared to i386.
Hopefully nobody expects them at a fixed place (Wine?) */
Expand All @@ -378,9 +378,12 @@ gdt_end:
/* zero the remaining page */
.fill PAGE_SIZE / 8 - GDT_ENTRIES,8,0

ENTRY(idt_table)
.rept 256
.quad 0
.quad 0
.endr
.section .bss, "aw", @nobits
.align L1_CACHE_BYTES
ENTRY(idt_table)
.skip 256 * 16

.section .bss.page_aligned, "aw", @nobits
.align PAGE_SIZE
ENTRY(empty_zero_page)
.skip PAGE_SIZE
2 changes: 1 addition & 1 deletion arch/x86_64/kernel/setup64.c
Original file line number Diff line number Diff line change
Expand Up @@ -33,7 +33,7 @@ cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;
struct x8664_pda *_cpu_pda[NR_CPUS] __read_mostly;
struct x8664_pda boot_cpu_pda[NR_CPUS] __cacheline_aligned;

struct desc_ptr idt_descr = { 256 * 16, (unsigned long) idt_table };
struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };

char boot_cpu_stack[IRQSTACKSIZE] __attribute__((section(".bss.page_aligned")));

Expand Down
2 changes: 0 additions & 2 deletions arch/x86_64/kernel/traps.c
Original file line number Diff line number Diff line change
Expand Up @@ -47,8 +47,6 @@
#include <asm/proto.h>
#include <asm/nmi.h>

extern struct gate_struct idt_table[256];

asmlinkage void divide_error(void);
asmlinkage void debug(void);
asmlinkage void nmi(void);
Expand Down

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