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authorJeremy Fitzhardinge <jeremy@goop.org>2006-12-07 04:14:03 +0300
committerAndi Kleen <andi@basil.nowhere.org>2006-12-07 04:14:03 +0300
commitb2938f880890ebfcccad356275e0000193153623 (patch)
treef2dcde93e6bd449369e4d305f081e9c12af99948
parent49d26b6eaa8e970c8cf6e299e6ccba2474191bf5 (diff)
downloadlinux-b2938f880890ebfcccad356275e0000193153623.tar.xz
[PATCH] i386: Implement smp_processor_id() with the PDA
Use the cpu_number in the PDA to implement raw_smp_processor_id. This is a little simpler than using thread_info, though the cpu field in thread_info cannot be removed since it is used for things other than getting the current CPU in common code. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Chuck Ebbert <76306.1226@compuserve.com> Cc: Zachary Amsden <zach@vmware.com> Cc: Jan Beulich <jbeulich@novell.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
-rw-r--r--arch/i386/kernel/asm-offsets.c4
-rw-r--r--arch/i386/kernel/cpu/common.c2
-rw-r--r--arch/i386/kernel/entry.S3
-rw-r--r--include/asm-i386/pda.h2
-rw-r--r--include/asm-i386/smp.h3
5 files changed, 10 insertions, 4 deletions
diff --git a/arch/i386/kernel/asm-offsets.c b/arch/i386/kernel/asm-offsets.c
index 9620872d3534..85f1b038e9c3 100644
--- a/arch/i386/kernel/asm-offsets.c
+++ b/arch/i386/kernel/asm-offsets.c
@@ -51,7 +51,6 @@ void foo(void)
OFFSET(TI_exec_domain, thread_info, exec_domain);
OFFSET(TI_flags, thread_info, flags);
OFFSET(TI_status, thread_info, status);
- OFFSET(TI_cpu, thread_info, cpu);
OFFSET(TI_preempt_count, thread_info, preempt_count);
OFFSET(TI_addr_limit, thread_info, addr_limit);
OFFSET(TI_restart_block, thread_info, restart_block);
@@ -97,4 +96,7 @@ void foo(void)
DEFINE(VDSO_PRELINK, VDSO_PRELINK);
OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx);
+
+ BLANK();
+ OFFSET(PDA_cpu, i386_pda, cpu_number);
}
diff --git a/arch/i386/kernel/cpu/common.c b/arch/i386/kernel/cpu/common.c
index 4e63d8ce602b..e476202b887f 100644
--- a/arch/i386/kernel/cpu/common.c
+++ b/arch/i386/kernel/cpu/common.c
@@ -650,6 +650,7 @@ __cpuinit int alloc_gdt(int cpu)
/* Initial PDA used by boot CPU */
struct i386_pda boot_pda = {
._pda = &boot_pda,
+ .cpu_number = 0,
};
static inline void set_kernel_gs(void)
@@ -694,6 +695,7 @@ __cpuinit int init_gdt(int cpu, struct task_struct *idle)
memset(pda, 0, sizeof(*pda));
pda->_pda = pda;
+ pda->cpu_number = cpu;
return 1;
}
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index b99d4a160078..d7423efaeea4 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -524,8 +524,7 @@ syscall_badsys:
#define FIXUP_ESPFIX_STACK \
/* since we are on a wrong stack, we cant make it a C code :( */ \
- GET_THREAD_INFO(%ebp); \
- movl TI_cpu(%ebp), %ebx; \
+ movl %gs:PDA_cpu, %ebx; \
PER_CPU(cpu_gdt_descr, %ebx); \
movl GDS_address(%ebx), %ebx; \
GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah); \
diff --git a/include/asm-i386/pda.h b/include/asm-i386/pda.h
index 4c39ccb1305c..f90fde22566d 100644
--- a/include/asm-i386/pda.h
+++ b/include/asm-i386/pda.h
@@ -11,6 +11,8 @@
struct i386_pda
{
struct i386_pda *_pda; /* pointer to self */
+
+ int cpu_number;
};
extern struct i386_pda *_cpu_pda[];
diff --git a/include/asm-i386/smp.h b/include/asm-i386/smp.h
index bd59c1508e71..64fe624c02ca 100644
--- a/include/asm-i386/smp.h
+++ b/include/asm-i386/smp.h
@@ -8,6 +8,7 @@
#include <linux/kernel.h>
#include <linux/threads.h>
#include <linux/cpumask.h>
+#include <asm/pda.h>
#endif
#ifdef CONFIG_X86_LOCAL_APIC
@@ -56,7 +57,7 @@ extern void cpu_uninit(void);
* 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() (current_thread_info()->cpu)
+#define raw_smp_processor_id() (read_pda(cpu_number))
extern cpumask_t cpu_callout_map;
extern cpumask_t cpu_callin_map;