diff options
| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2007-05-02 19:27:16 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2007-05-02 19:27:16 +0200 |
| commit | 7c3576d261ce046789a7db14f43303f8120910c7 (patch) | |
| tree | ad27a8459bbcdb183fe2411aec3b840942992ad5 /include/asm-i386/smp.h | |
| parent | [PATCH] i386: Page-align the GDT (diff) | |
| download | linux-7c3576d261ce046789a7db14f43303f8120910c7.tar.xz linux-7c3576d261ce046789a7db14f43303f8120910c7.zip | |
[PATCH] i386: Convert PDA into the percpu section
Currently x86 (similar to x84-64) has a special per-cpu structure
called "i386_pda" which can be easily and efficiently referenced via
the %fs register. An ELF section is more flexible than a structure,
allowing any piece of code to use this area. Indeed, such a section
already exists: the per-cpu area.
So this patch:
(1) Removes the PDA and uses per-cpu variables for each current member.
(2) Replaces the __KERNEL_PDA segment with __KERNEL_PERCPU.
(3) Creates a per-cpu mirror of __per_cpu_offset called this_cpu_off, which
can be used to calculate addresses for this CPU's variables.
(4) Simplifies startup, because %fs doesn't need to be loaded with a
special segment at early boot; it can be deferred until the first
percpu area is allocated (or never for UP).
The result is less code and one less x86-specific concept.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Diffstat (limited to 'include/asm-i386/smp.h')
| -rw-r--r-- | include/asm-i386/smp.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/asm-i386/smp.h b/include/asm-i386/smp.h index 2d083cb4ca93..090abc1da32a 100644 --- a/include/asm-i386/smp.h +++ b/include/asm-i386/smp.h @@ -8,7 +8,6 @@ #include <linux/kernel.h> #include <linux/threads.h> #include <linux/cpumask.h> -#include <asm/pda.h> #endif #if defined(CONFIG_X86_LOCAL_APIC) && !defined(__ASSEMBLY__) @@ -112,7 +111,8 @@ do { } while (0) * from the initial startup. We map APIC_BASE very early in page_setup(), * so this is correct in the x86 case. */ -#define raw_smp_processor_id() (read_pda(cpu_number)) +DECLARE_PER_CPU(int, cpu_number); +#define raw_smp_processor_id() (x86_read_percpu(cpu_number)) extern cpumask_t cpu_callout_map; extern cpumask_t cpu_callin_map; |