[PATCH 3/3] x86-64: Move cpu number from PDA to per-cpu and consolidate with 32-bit.

From: Brian Gerst
Date: Tue Dec 23 2008 - 12:15:53 EST


A simple example of what can now be done to consolidate with the 32-bit
code.

Signed-off-by: Brian Gerst <brgerst@xxxxxxxxx>
---
arch/x86/include/asm/pda.h | 2 +-
arch/x86/include/asm/smp.h | 4 +---
arch/x86/kernel/asm-offsets_64.c | 1 -
arch/x86/kernel/cpu/common.c | 1 -
arch/x86/kernel/process_32.c | 3 ---
arch/x86/kernel/setup_percpu.c | 4 ++++
arch/x86/kernel/smpcommon.c | 1 -
7 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/pda.h b/arch/x86/include/asm/pda.h
index b008127..3ace2b9 100644
--- a/arch/x86/include/asm/pda.h
+++ b/arch/x86/include/asm/pda.h
@@ -15,7 +15,7 @@ struct x8664_pda {
unsigned long kernelstack; /* 16 top of kernel stack for current */
unsigned long oldrsp; /* 24 user rsp for system call */
int irqcount; /* 32 Irq nesting counter. Starts -1 */
- unsigned int cpunumber; /* 36 Logical CPU number */
+ unsigned int unused1; /* 36 was cpunumber */
#ifdef CONFIG_CC_STACKPROTECTOR
unsigned long stack_canary; /* 40 stack canary value */
/* gcc-ABI: this canary MUST be at
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index d12811c..f2e4b9c 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -34,9 +34,7 @@ extern cpumask_t cpu_initialized;
DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);
DECLARE_PER_CPU(cpumask_t, cpu_core_map);
DECLARE_PER_CPU(u16, cpu_llc_id);
-#ifdef CONFIG_X86_32
DECLARE_PER_CPU(int, cpu_number);
-#endif

DECLARE_EARLY_PER_CPU(u16, x86_cpu_to_apicid);
DECLARE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid);
@@ -169,7 +167,7 @@ extern unsigned disabled_cpus __cpuinitdata;
extern int safe_smp_processor_id(void);

#elif defined(CONFIG_X86_64_SMP)
-#define raw_smp_processor_id() read_pda(cpunumber)
+#define raw_smp_processor_id() (x86_read_percpu(cpu_number))

#define stack_smp_processor_id() \
({ \
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index 7fcf63d..b14bb4e 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -51,7 +51,6 @@ int main(void)
ENTRY(oldrsp);
ENTRY(pcurrent);
ENTRY(irqcount);
- ENTRY(cpunumber);
ENTRY(irqstackptr);
ENTRY(data_offset);
BLANK();
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 7d741ef..82ad755 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -876,7 +876,6 @@ void __cpuinit pda_init(int cpu)
wrmsrl(MSR_GS_BASE, pda);
mb();

- pda->cpunumber = cpu;
pda->irqcount = -1;
pda->kernelstack = (unsigned long)stack_thread_info() -
PDA_STACKOFFSET + THREAD_SIZE;
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 0a1302f..4bb0a7d 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -65,9 +65,6 @@ asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
EXPORT_PER_CPU_SYMBOL(current_task);

-DEFINE_PER_CPU(int, cpu_number);
-EXPORT_PER_CPU_SYMBOL(cpu_number);
-
/*
* Return saved PC of a blocked thread.
*/
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index fb0ccdc..f013781 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -15,6 +15,9 @@
#include <asm/apicdef.h>
#include <asm/highmem.h>

+DEFINE_PER_CPU(int, cpu_number);
+EXPORT_PER_CPU_SYMBOL(cpu_number);
+
#ifdef CONFIG_X86_LOCAL_APIC
unsigned int num_processors;
unsigned disabled_cpus __cpuinitdata;
@@ -133,6 +136,7 @@ void __init setup_per_cpu_areas(void)
memset(&per_cpu(pda, cpu), 0, sizeof(struct x8664_pda));
per_cpu(pda, cpu).data_offset = __per_cpu_offset[cpu];
#endif
+ per_cpu(cpu_number, cpu) = cpu;
}

#ifdef CONFIG_X86_64
diff --git a/arch/x86/kernel/smpcommon.c b/arch/x86/kernel/smpcommon.c
index 397e309..db7c5a6 100644
--- a/arch/x86/kernel/smpcommon.c
+++ b/arch/x86/kernel/smpcommon.c
@@ -25,6 +25,5 @@ __cpuinit void init_gdt(int cpu)
GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);

per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu];
- per_cpu(cpu_number, cpu) = cpu;
}
#endif
--
1.6.1.rc1

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