From 7c3576d261ce046789a7db14f43303f8120910c7 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Wed, 2 May 2007 19:27:16 +0200 Subject: [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 Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Andi Kleen Cc: Andi Kleen --- arch/i386/kernel/asm-offsets.c | 5 -- arch/i386/kernel/cpu/common.c | 17 +----- arch/i386/kernel/entry.S | 5 +- arch/i386/kernel/head.S | 31 ++-------- arch/i386/kernel/i386_ksyms.c | 2 - arch/i386/kernel/irq.c | 3 + arch/i386/kernel/process.c | 12 +++- arch/i386/kernel/smpboot.c | 30 +++++----- arch/i386/kernel/vmi.c | 6 +- arch/i386/kernel/vmlinux.lds.S | 1 - include/asm-i386/current.h | 5 +- include/asm-i386/irq_regs.h | 12 ++-- include/asm-i386/pda.h | 99 ------------------------------- include/asm-i386/percpu.h | 132 ++++++++++++++++++++++++++++++++++++++--- include/asm-i386/processor.h | 2 +- include/asm-i386/segment.h | 6 +- include/asm-i386/smp.h | 4 +- 17 files changed, 177 insertions(+), 195 deletions(-) delete mode 100644 include/asm-i386/pda.h diff --git a/arch/i386/kernel/asm-offsets.c b/arch/i386/kernel/asm-offsets.c index d558adfc293..b05e85fd1c1 100644 --- a/arch/i386/kernel/asm-offsets.c +++ b/arch/i386/kernel/asm-offsets.c @@ -15,7 +15,6 @@ #include #include #include -#include #define DEFINE(sym, val) \ asm volatile("\n->" #sym " %0 " #val : : "i" (val)) @@ -101,10 +100,6 @@ void foo(void) OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx); - BLANK(); - OFFSET(PDA_cpu, i386_pda, cpu_number); - OFFSET(PDA_pcurrent, i386_pda, pcurrent); - #ifdef CONFIG_PARAVIRT BLANK(); OFFSET(PARAVIRT_enabled, paravirt_ops, paravirt_enabled); diff --git a/arch/i386/kernel/cpu/common.c b/arch/i386/kernel/cpu/common.c index 7a4c036d93c..27e00565f5e 100644 --- a/arch/i386/kernel/cpu/common.c +++ b/arch/i386/kernel/cpu/common.c @@ -18,7 +18,6 @@ #include #include #endif -#include #include "cpu.h" @@ -47,13 +46,10 @@ DEFINE_PER_CPU(struct gdt_page, gdt_page) = { .gdt = { [GDT_ENTRY_APMBIOS_BASE+2] = { 0x0000ffff, 0x00409200 }, /* data */ [GDT_ENTRY_ESPFIX_SS] = { 0x00000000, 0x00c09200 }, - [GDT_ENTRY_PDA] = { 0x00000000, 0x00c09200 }, /* set in setup_pda */ + [GDT_ENTRY_PERCPU] = { 0x00000000, 0x00000000 }, } }; EXPORT_PER_CPU_SYMBOL_GPL(gdt_page); -DEFINE_PER_CPU(struct i386_pda, _cpu_pda); -EXPORT_PER_CPU_SYMBOL(_cpu_pda); - static int cachesize_override __cpuinitdata = -1; static int disable_x86_fxsr __cpuinitdata; static int disable_x86_serial_nr __cpuinitdata = 1; @@ -634,21 +630,14 @@ void __init early_cpu_init(void) #endif } -/* Make sure %gs is initialized properly in idle threads */ +/* Make sure %fs is initialized properly in idle threads */ struct pt_regs * __devinit idle_regs(struct pt_regs *regs) { memset(regs, 0, sizeof(struct pt_regs)); - regs->xfs = __KERNEL_PDA; + regs->xfs = __KERNEL_PERCPU; return regs; } -/* Initial PDA used by boot CPU */ -struct i386_pda boot_pda = { - ._pda = &boot_pda, - .cpu_number = 0, - .pcurrent = &init_task, -}; - /* * cpu_init() initializes state that is per-CPU. Some data is already * initialized (naturally) in the bootstrap process, such as the GDT diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S index 3e4aa1fd33e..7f92ceb428a 100644 --- a/arch/i386/kernel/entry.S +++ b/arch/i386/kernel/entry.S @@ -132,7 +132,7 @@ VM_MASK = 0x00020000 movl $(__USER_DS), %edx; \ movl %edx, %ds; \ movl %edx, %es; \ - movl $(__KERNEL_PDA), %edx; \ + movl $(__KERNEL_PERCPU), %edx; \ movl %edx, %fs #define RESTORE_INT_REGS \ @@ -556,7 +556,6 @@ END(syscall_badsys) #define FIXUP_ESPFIX_STACK \ /* since we are on a wrong stack, we cant make it a C code :( */ \ - movl %fs:PDA_cpu, %ebx; \ PER_CPU(gdt_page, %ebx); \ GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah); \ addl %esp, %eax; \ @@ -681,7 +680,7 @@ error_code: pushl %fs CFI_ADJUST_CFA_OFFSET 4 /*CFI_REL_OFFSET fs, 0*/ - movl $(__KERNEL_PDA), %ecx + movl $(__KERNEL_PERCPU), %ecx movl %ecx, %fs UNWIND_ESPFIX_STACK popl %ecx diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S index bb36c24311b..12277d8938d 100644 --- a/arch/i386/kernel/head.S +++ b/arch/i386/kernel/head.S @@ -317,12 +317,12 @@ is386: movl $2,%ecx # set MP movl %eax,%cr0 call check_x87 - call setup_pda lgdt early_gdt_descr lidt idt_descr ljmp $(__KERNEL_CS),$1f 1: movl $(__KERNEL_DS),%eax # reload all the segment registers movl %eax,%ss # after changing gdt. + movl %eax,%fs # gets reset once there's real percpu movl $(__USER_DS),%eax # DS/ES contains default USER segment movl %eax,%ds @@ -332,16 +332,17 @@ is386: movl $2,%ecx # set MP movl %eax,%gs lldt %ax - movl $(__KERNEL_PDA),%eax - mov %eax,%fs - cld # gcc2 wants the direction flag cleared at all times pushl $0 # fake return address for unwinder #ifdef CONFIG_SMP movb ready, %cl movb $1, ready cmpb $0,%cl # the first CPU calls start_kernel - jne initialize_secondary # all other CPUs call initialize_secondary + je 1f + movl $(__KERNEL_PERCPU), %eax + movl %eax,%fs # set this cpu's percpu + jmp initialize_secondary # all other CPUs call initialize_secondary +1: #endif /* CONFIG_SMP */ jmp start_kernel @@ -364,23 +365,6 @@ check_x87: .byte 0xDB,0xE4 /* fsetpm for 287, ignored by 387 */ ret -/* - * Point the GDT at this CPU's PDA. On boot this will be - * cpu_gdt_table and boot_pda; for secondary CPUs, these will be - * that CPU's GDT and PDA. - */ -ENTRY(setup_pda) - /* get the PDA pointer */ - movl start_pda, %eax - - /* slot the PDA address into the GDT */ - mov early_gdt_descr+2, %ecx - mov %ax, (__KERNEL_PDA+0+2)(%ecx) /* base & 0x0000ffff */ - shr $16, %eax - mov %al, (__KERNEL_PDA+4+0)(%ecx) /* base & 0x00ff0000 */ - mov %ah, (__KERNEL_PDA+4+3)(%ecx) /* base & 0xff000000 */ - ret - /* * setup_idt * @@ -553,9 +537,6 @@ ENTRY(empty_zero_page) * This starts the data section. */ .data -ENTRY(start_pda) - .long boot_pda - ENTRY(stack_start) .long init_thread_union+THREAD_SIZE .long __BOOT_DS diff --git a/arch/i386/kernel/i386_ksyms.c b/arch/i386/kernel/i386_ksyms.c index 4afe26e8626..e3d4b73bfdb 100644 --- a/arch/i386/kernel/i386_ksyms.c +++ b/arch/i386/kernel/i386_ksyms.c @@ -28,5 +28,3 @@ EXPORT_SYMBOL(__read_lock_failed); #endif EXPORT_SYMBOL(csum_partial); - -EXPORT_SYMBOL(_proxy_pda); diff --git a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c index 8db8d514c9c..d2daf672f4a 100644 --- a/arch/i386/kernel/irq.c +++ b/arch/i386/kernel/irq.c @@ -24,6 +24,9 @@ DEFINE_PER_CPU(irq_cpustat_t, irq_stat) ____cacheline_internodealigned_in_smp; EXPORT_PER_CPU_SYMBOL(irq_stat); +DEFINE_PER_CPU(struct pt_regs *, irq_regs); +EXPORT_PER_CPU_SYMBOL(irq_regs); + /* * 'what should we do if we get a hw irq event on an illegal vector'. * each architecture has to answer this themselves. diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c index 5fb9524c6f4..61999479b7a 100644 --- a/arch/i386/kernel/process.c +++ b/arch/i386/kernel/process.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include @@ -57,7 +58,6 @@ #include #include -#include asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); @@ -66,6 +66,12 @@ static int hlt_counter; unsigned long boot_option_idle_override = 0; EXPORT_SYMBOL(boot_option_idle_override); +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. */ @@ -342,7 +348,7 @@ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) regs.xds = __USER_DS; regs.xes = __USER_DS; - regs.xfs = __KERNEL_PDA; + regs.xfs = __KERNEL_PERCPU; regs.orig_eax = -1; regs.eip = (unsigned long) kernel_thread_helper; regs.xcs = __KERNEL_CS | get_kernel_rpl(); @@ -711,7 +717,7 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas if (prev->gs | next->gs) loadsegment(gs, next->gs); - write_pda(pcurrent, next_p); + x86_write_percpu(current_task, next_p); return prev_p; } diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c index 61e2842add3..f79b6233db7 100644 --- a/arch/i386/kernel/smpboot.c +++ b/arch/i386/kernel/smpboot.c @@ -53,7 +53,6 @@ #include #include #include -#include #include #include @@ -99,6 +98,9 @@ EXPORT_SYMBOL(x86_cpu_to_apicid); u8 apicid_2_node[MAX_APICID]; +DEFINE_PER_CPU(unsigned long, this_cpu_off); +EXPORT_PER_CPU_SYMBOL(this_cpu_off); + /* * Trampoline 80x86 program as an array. */ @@ -456,7 +458,6 @@ extern struct { void * esp; unsigned short ss; } stack_start; -extern struct i386_pda *start_pda; #ifdef CONFIG_NUMA @@ -784,20 +785,17 @@ static inline struct task_struct * alloc_idle_task(int cpu) /* Initialize the CPU's GDT. This is either the boot CPU doing itself (still using the master per-cpu area), or a CPU doing it for a secondary which will soon come up. */ -static __cpuinit void init_gdt(int cpu, struct task_struct *idle) +static __cpuinit void init_gdt(int cpu) { struct desc_struct *gdt = get_cpu_gdt_table(cpu); - struct i386_pda *pda = &per_cpu(_cpu_pda, cpu); - pack_descriptor((u32 *)&gdt[GDT_ENTRY_PDA].a, - (u32 *)&gdt[GDT_ENTRY_PDA].b, - (unsigned long)pda, sizeof(*pda) - 1, - 0x80 | DESCTYPE_S | 0x2, 0); /* present read-write data segment */ + pack_descriptor((u32 *)&gdt[GDT_ENTRY_PERCPU].a, + (u32 *)&gdt[GDT_ENTRY_PERCPU].b, + __per_cpu_offset[cpu], 0xFFFFF, + 0x80 | DESCTYPE_S | 0x2, 0x8); - memset(pda, 0, sizeof(*pda)); - pda->_pda = pda; - pda->cpu_number = cpu; - pda->pcurrent = idle; + per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu]; + per_cpu(cpu_number, cpu) = cpu; } /* Defined in head.S */ @@ -824,9 +822,9 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu) if (IS_ERR(idle)) panic("failed fork for CPU %d", cpu); - init_gdt(cpu, idle); + init_gdt(cpu); + per_cpu(current_task, cpu) = idle; early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu); - start_pda = cpu_pda(cpu); idle->thread.eip = (unsigned long) start_secondary; /* start_eip had better be page-aligned! */ @@ -1188,14 +1186,14 @@ static inline void switch_to_new_gdt(void) gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id()); gdt_descr.size = GDT_SIZE - 1; load_gdt(&gdt_descr); - asm volatile ("mov %0, %%fs" : : "r" (__KERNEL_PDA) : "memory"); + asm("mov %0, %%fs" : : "r" (__KERNEL_PERCPU) : "memory"); } void __init native_smp_prepare_boot_cpu(void) { unsigned int cpu = smp_processor_id(); - init_gdt(cpu, current); + init_gdt(cpu); switch_to_new_gdt(); cpu_set(cpu, cpu_online_map); diff --git a/arch/i386/kernel/vmi.c b/arch/i386/kernel/vmi.c index ccad7ee960a..12312988c62 100644 --- a/arch/i386/kernel/vmi.c +++ b/arch/i386/kernel/vmi.c @@ -504,8 +504,6 @@ static void vmi_pmd_clear(pmd_t *pmd) #endif #ifdef CONFIG_SMP -extern void setup_pda(void); - static void __devinit vmi_startup_ipi_hook(int phys_apicid, unsigned long start_eip, unsigned long start_esp) @@ -530,13 +528,11 @@ vmi_startup_ipi_hook(int phys_apicid, unsigned long start_eip, ap.ds = __USER_DS; ap.es = __USER_DS; - ap.fs = __KERNEL_PDA; + ap.fs = __KERNEL_PERCPU; ap.gs = 0; ap.eflags = 0; - setup_pda(); - #ifdef CONFIG_X86_PAE /* efer should match BSP efer. */ if (cpu_has_nx) { diff --git a/arch/i386/kernel/vmlinux.lds.S b/arch/i386/kernel/vmlinux.lds.S index 2ce4aa185fc..d125784ddf5 100644 --- a/arch/i386/kernel/vmlinux.lds.S +++ b/arch/i386/kernel/vmlinux.lds.S @@ -26,7 +26,6 @@ OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386") OUTPUT_ARCH(i386) ENTRY(phys_startup_32) jiffies = jiffies_64; -_proxy_pda = 1; PHDRS { text PT_LOAD FLAGS(5); /* R_E */ diff --git a/include/asm-i386/current.h b/include/asm-i386/current.h index 5252ee0f6d7..d3524853991 100644 --- a/include/asm-i386/current.h +++ b/include/asm-i386/current.h @@ -1,14 +1,15 @@ #ifndef _I386_CURRENT_H #define _I386_CURRENT_H -#include #include +#include struct task_struct; +DECLARE_PER_CPU(struct task_struct *, current_task); static __always_inline struct task_struct *get_current(void) { - return read_pda(pcurrent); + return x86_read_percpu(current_task); } #define current get_current() diff --git a/include/asm-i386/irq_regs.h b/include/asm-i386/irq_regs.h index a1b3f7f594a..3368b20c0b4 100644 --- a/include/asm-i386/irq_regs.h +++ b/include/asm-i386/irq_regs.h @@ -1,25 +1,27 @@ /* * Per-cpu current frame pointer - the location of the last exception frame on - * the stack, stored in the PDA. + * the stack, stored in the per-cpu area. * * Jeremy Fitzhardinge */ #ifndef _ASM_I386_IRQ_REGS_H #define _ASM_I386_IRQ_REGS_H -#include +#include + +DECLARE_PER_CPU(struct pt_regs *, irq_regs); static inline struct pt_regs *get_irq_regs(void) { - return read_pda(irq_regs); + return x86_read_percpu(irq_regs); } static inline struct pt_regs *set_irq_regs(struct pt_regs *new_regs) { struct pt_regs *old_regs; - old_regs = read_pda(irq_regs); - write_pda(irq_regs, new_regs); + old_regs = get_irq_regs(); + x86_write_percpu(irq_regs, new_regs); return old_regs; } diff --git a/include/asm-i386/pda.h b/include/asm-i386/pda.h deleted file mode 100644 index aef7f732f77..00000000000 --- a/include/asm-i386/pda.h +++ /dev/null @@ -1,99 +0,0 @@ -/* - Per-processor Data Areas - Jeremy Fitzhardinge 2006 - Based on asm-x86_64/pda.h by Andi Kleen. - */ -#ifndef _I386_PDA_H -#define _I386_PDA_H - -#include -#include -#include - -struct i386_pda -{ - struct i386_pda *_pda; /* pointer to self */ - - int cpu_number; - struct task_struct *pcurrent; /* current process */ - struct pt_regs *irq_regs; -}; - -DECLARE_PER_CPU(struct i386_pda, _cpu_pda); -#define cpu_pda(i) (&per_cpu(_cpu_pda, (i))) -#define pda_offset(field) offsetof(struct i386_pda, field) - -extern void __bad_pda_field(void); - -/* This variable is never instantiated. It is only used as a stand-in - for the real per-cpu PDA memory, so that gcc can understand what - memory operations the inline asms() below are performing. This - eliminates the need to make the asms volatile or have memory - clobbers, so gcc can readily analyse them. */ -extern struct i386_pda _proxy_pda; - -#define pda_to_op(op,field,val) \ - do { \ - typedef typeof(_proxy_pda.field) T__; \ - if (0) { T__ tmp__; tmp__ = (val); } \ - switch (sizeof(_proxy_pda.field)) { \ - case 1: \ - asm(op "b %1,%%fs:%c2" \ - : "+m" (_proxy_pda.field) \ - :"ri" ((T__)val), \ - "i"(pda_offset(field))); \ - break; \ - case 2: \ - asm(op "w %1,%%fs:%c2" \ - : "+m" (_proxy_pda.field) \ - :"ri" ((T__)val), \ - "i"(pda_offset(field))); \ - break; \ - case 4: \ - asm(op "l %1,%%fs:%c2" \ - : "+m" (_proxy_pda.field) \ - :"ri" ((T__)val), \ - "i"(pda_offset(field))); \ - break; \ - default: __bad_pda_field(); \ - } \ - } while (0) - -#define pda_from_op(op,field) \ - ({ \ - typeof(_proxy_pda.field) ret__; \ - switch (sizeof(_proxy_pda.field)) { \ - case 1: \ - asm(op "b %%fs:%c1,%0" \ - : "=r" (ret__) \ - : "i" (pda_offset(field)), \ - "m" (_proxy_pda.field)); \ - break; \ - case 2: \ - asm(op "w %%fs:%c1,%0" \ - : "=r" (ret__) \ - : "i" (pda_offset(field)), \ - "m" (_proxy_pda.field)); \ - break; \ - case 4: \ - asm(op "l %%fs:%c1,%0" \ - : "=r" (ret__) \ - : "i" (pda_offset(field)), \ - "m" (_proxy_pda.field)); \ - break; \ - default: __bad_pda_field(); \ - } \ - ret__; }) - -/* Return a pointer to a pda field */ -#define pda_addr(field) \ - ((typeof(_proxy_pda.field) *)((unsigned char *)read_pda(_pda) + \ - pda_offset(field))) - -#define read_pda(field) pda_from_op("mov",field) -#define write_pda(field,val) pda_to_op("mov",field,val) -#define add_pda(field,val) pda_to_op("add",field,val) -#define sub_pda(field,val) pda_to_op("sub",field,val) -#define or_pda(field,val) pda_to_op("or",field,val) - -#endif /* _I386_PDA_H */ diff --git a/include/asm-i386/percpu.h b/include/asm-i386/percpu.h index a10e7c68ae9..c5f12f0d9c2 100644 --- a/include/asm-i386/percpu.h +++ b/include/asm-i386/percpu.h @@ -1,9 +1,30 @@ #ifndef __ARCH_I386_PERCPU__ #define __ARCH_I386_PERCPU__ -#ifndef __ASSEMBLY__ -#include -#else +#ifdef __ASSEMBLY__ + +/* + * PER_CPU finds an address of a per-cpu variable. + * + * Args: + * var - variable name + * reg - 32bit register + * + * The resulting address is stored in the "reg" argument. + * + * Example: + * PER_CPU(cpu_gdt_descr, %ebx) + */ +#ifdef CONFIG_SMP +#define PER_CPU(var, reg) \ + movl %fs:per_cpu__this_cpu_off, reg; \ + addl $per_cpu__##var, reg +#else /* ! SMP */ +#define PER_CPU(var, reg) \ + movl $per_cpu__##var, reg; +#endif /* SMP */ + +#else /* ...!ASSEMBLY */ /* * PER_CPU finds an address of a per-cpu variable. @@ -18,14 +39,107 @@ * PER_CPU(cpu_gdt_descr, %ebx) */ #ifdef CONFIG_SMP -#define PER_CPU(var, cpu) \ - movl __per_cpu_offset(,cpu,4), cpu; \ - addl $per_cpu__##var, cpu; -#else /* ! SMP */ -#define PER_CPU(var, cpu) \ - movl $per_cpu__##var, cpu; +/* Same as generic implementation except for optimized local access. */ +#define __GENERIC_PER_CPU + +/* This is used for other cpus to find our section. */ +extern unsigned long __per_cpu_offset[]; + +/* Separate out the type, so (int[3], foo) works. */ +#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name +#define DEFINE_PER_CPU(type, name) \ + __attribute__((__section__(".data.percpu"))) __typeof__(type) per_cpu__##name + +/* We can use this directly for local CPU (faster). */ +DECLARE_PER_CPU(unsigned long, this_cpu_off); + +/* var is in discarded region: offset to particular copy we want */ +#define per_cpu(var, cpu) (*({ \ + extern int simple_indentifier_##var(void); \ + RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]); })) + +#define __raw_get_cpu_var(var) (*({ \ + extern int simple_indentifier_##var(void); \ + RELOC_HIDE(&per_cpu__##var, x86_read_percpu(this_cpu_off)); \ +})) + +#define __get_cpu_var(var) __raw_get_cpu_var(var) + +/* A macro to avoid #include hell... */ +#define percpu_modcopy(pcpudst, src, size) \ +do { \ + unsigned int __i; \ + for_each_possible_cpu(__i) \ + memcpy((pcpudst)+__per_cpu_offset[__i], \ + (src), (size)); \ +} while (0) + +#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var) +#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var) + +/* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */ +#define __percpu_seg "%%fs:" +#else /* !SMP */ +#include +#define __percpu_seg "" #endif /* SMP */ +/* For arch-specific code, we can use direct single-insn ops (they + * don't give an lvalue though). */ +extern void __bad_percpu_size(void); + +#define percpu_to_op(op,var,val) \ + do { \ + typedef typeof(var) T__; \ + if (0) { T__ tmp__; tmp__ = (val); } \ + switch (sizeof(var)) { \ + case 1: \ + asm(op "b %1,"__percpu_seg"%0" \ + : "+m" (var) \ + :"ri" ((T__)val)); \ + break; \ + case 2: \ + asm(op "w %1,"__percpu_seg"%0" \ + : "+m" (var) \ + :"ri" ((T__)val)); \ + break; \ + case 4: \ + asm(op "l %1,"__percpu_seg"%0" \ + : "+m" (var) \ + :"ri" ((T__)val)); \ + break; \ + default: __bad_percpu_size(); \ + } \ + } while (0) + +#define percpu_from_op(op,var) \ + ({ \ + typeof(var) ret__; \ + switch (sizeof(var)) { \ + case 1: \ + asm(op "b "__percpu_seg"%1,%0" \ + : "=r" (ret__) \ + : "m" (var)); \ + break; \ + case 2: \ + asm(op "w "__percpu_seg"%1,%0" \ + : "=r" (ret__) \ + : "m" (var)); \ + break; \ + case 4: \ + asm(op "l "__percpu_seg"%1,%0" \ + : "=r" (ret__) \ + : "m" (var)); \ + break; \ + default: __bad_percpu_size(); \ + } \ + ret__; }) + +#define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var) +#define x86_write_percpu(var,val) percpu_to_op("mov", per_cpu__##var, val) +#define x86_add_percpu(var,val) percpu_to_op("add", per_cpu__##var, val) +#define x86_sub_percpu(var,val) percpu_to_op("sub", per_cpu__##var, val) +#define x86_or_percpu(var,val) percpu_to_op("or", per_cpu__##var, val) #endif /* !__ASSEMBLY__ */ #endif /* __ARCH_I386_PERCPU__ */ diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h index 92226047464..ced2da8a0d6 100644 --- a/include/asm-i386/processor.h +++ b/include/asm-i386/processor.h @@ -377,7 +377,7 @@ struct thread_struct { .vm86_info = NULL, \ .sysenter_cs = __KERNEL_CS, \ .io_bitmap_ptr = NULL, \ - .fs = __KERNEL_PDA, \ + .fs = __KERNEL_PERCPU, \ } /* diff --git a/include/asm-i386/segment.h b/include/asm-i386/segment.h index 065f10bfa48..07e70624d87 100644 --- a/include/asm-i386/segment.h +++ b/include/asm-i386/segment.h @@ -39,7 +39,7 @@ * 25 - APM BIOS support * * 26 - ESPFIX small SS - * 27 - PDA [ per-cpu private data area ] + * 27 - per-cpu [ offset to per-cpu data area ] * 28 - unused * 29 - unused * 30 - unused @@ -74,8 +74,8 @@ #define GDT_ENTRY_ESPFIX_SS (GDT_ENTRY_KERNEL_BASE + 14) #define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS * 8) -#define GDT_ENTRY_PDA (GDT_ENTRY_KERNEL_BASE + 15) -#define __KERNEL_PDA (GDT_ENTRY_PDA * 8) +#define GDT_ENTRY_PERCPU (GDT_ENTRY_KERNEL_BASE + 15) +#define __KERNEL_PERCPU (GDT_ENTRY_PERCPU * 8) #define GDT_ENTRY_DOUBLEFAULT_TSS 31 diff --git a/include/asm-i386/smp.h b/include/asm-i386/smp.h index 2d083cb4ca9..090abc1da32 100644 --- a/include/asm-i386/smp.h +++ b/include/asm-i386/smp.h @@ -8,7 +8,6 @@ #include #include #include -#include #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; -- cgit v1.2.3