diff options
| author | Rusty Russell <rusty@rustcorp.com.au> | 2007-05-02 19:27:10 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2007-05-02 19:27:10 +0200 |
| commit | bf50467204b435421d8de33ad080fa46c6f3d50b (patch) | |
| tree | 87a27c6f23f28d0e7dacee4ac45986e897d244a8 /arch/i386/kernel/head.S | |
| parent | ae1ee11be77f51cedb6c569887dddc70c163ab6d (diff) | |
[PATCH] i386: Use per-cpu GDT immediately upon boot
Now we are no longer dynamically allocating the GDT, we don't need the
"cpu_gdt_table" at all: we can switch straight from "boot_gdt_table" to the
per-cpu GDT. This means initializing the cpu_gdt array in C.
The boot CPU uses the per-cpu var directly, then in smp_prepare_cpus() it
switches to the per-cpu copy just allocated. For secondary CPUs, the
early_gdt_descr is set to point directly to their per-cpu copy.
For UP the code is very simple: it keeps using the "per-cpu" GDT as per SMP,
but we never have to move.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/i386/kernel/head.S')
| -rw-r--r-- | arch/i386/kernel/head.S | 55 |
1 files changed, 1 insertions, 54 deletions
diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S index cb185f40c28..633fd2f4742 100644 --- a/arch/i386/kernel/head.S +++ b/arch/i386/kernel/head.S @@ -599,7 +599,7 @@ idt_descr: .word 0 # 32 bit align gdt_desc.address ENTRY(early_gdt_descr) .word GDT_ENTRIES*8-1 - .long cpu_gdt_table + .long per_cpu__cpu_gdt /* Overwritten for secondary CPUs */ /* * The boot_gdt_table must mirror the equivalent in setup.S and is @@ -610,56 +610,3 @@ ENTRY(boot_gdt_table) .fill GDT_ENTRY_BOOT_CS,8,0 .quad 0x00cf9a000000ffff /* kernel 4GB code at 0x00000000 */ .quad 0x00cf92000000ffff /* kernel 4GB data at 0x00000000 */ - -/* - * The Global Descriptor Table contains 32 quadwords, per-CPU. - */ - .align L1_CACHE_BYTES -ENTRY(cpu_gdt_table) - .quad 0x0000000000000000 /* NULL descriptor */ - .quad 0x0000000000000000 /* 0x0b reserved */ - .quad 0x0000000000000000 /* 0x13 reserved */ - .quad 0x0000000000000000 /* 0x1b reserved */ - .quad 0x0000000000000000 /* 0x20 unused */ - .quad 0x0000000000000000 /* 0x28 unused */ - .quad 0x0000000000000000 /* 0x33 TLS entry 1 */ - .quad 0x0000000000000000 /* 0x3b TLS entry 2 */ - .quad 0x0000000000000000 /* 0x43 TLS entry 3 */ - .quad 0x0000000000000000 /* 0x4b reserved */ - .quad 0x0000000000000000 /* 0x53 reserved */ - .quad 0x0000000000000000 /* 0x5b reserved */ - - .quad 0x00cf9a000000ffff /* 0x60 kernel 4GB code at 0x00000000 */ - .quad 0x00cf92000000ffff /* 0x68 kernel 4GB data at 0x00000000 */ - .quad 0x00cffa000000ffff /* 0x73 user 4GB code at 0x00000000 */ - .quad 0x00cff2000000ffff /* 0x7b user 4GB data at 0x00000000 */ - - .quad 0x0000000000000000 /* 0x80 TSS descriptor */ - .quad 0x0000000000000000 /* 0x88 LDT descriptor */ - - /* - * Segments used for calling PnP BIOS have byte granularity. - * The code segments and data segments have fixed 64k limits, - * the transfer segment sizes are set at run time. - */ - .quad 0x00409a000000ffff /* 0x90 32-bit code */ - .quad 0x00009a000000ffff /* 0x98 16-bit code */ - .quad 0x000092000000ffff /* 0xa0 16-bit data */ - .quad 0x0000920000000000 /* 0xa8 16-bit data */ - .quad 0x0000920000000000 /* 0xb0 16-bit data */ - - /* - * The APM segments have byte granularity and their bases - * are set at run time. All have 64k limits. - */ - .quad 0x00409a000000ffff /* 0xb8 APM CS code */ - .quad 0x00009a000000ffff /* 0xc0 APM CS 16 code (16 bit) */ - .quad 0x004092000000ffff /* 0xc8 APM DS data */ - - .quad 0x00c0920000000000 /* 0xd0 - ESPFIX SS */ - .quad 0x00cf92000000ffff /* 0xd8 - PDA */ - .quad 0x0000000000000000 /* 0xe0 - unused */ - .quad 0x0000000000000000 /* 0xe8 - unused */ - .quad 0x0000000000000000 /* 0xf0 - unused */ - .quad 0x0000000000000000 /* 0xf8 - GDT entry 31: double-fault TSS */ - |