diff options
Diffstat (limited to 'arch/x86/include/asm/pda.h')
| -rw-r--r-- | arch/x86/include/asm/pda.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pda.h b/arch/x86/include/asm/pda.h new file mode 100644 index 00000000000..3fea2fdb330 --- /dev/null +++ b/arch/x86/include/asm/pda.h @@ -0,0 +1,137 @@ +#ifndef _ASM_X86_PDA_H +#define _ASM_X86_PDA_H + +#ifndef __ASSEMBLY__ +#include <linux/stddef.h> +#include <linux/types.h> +#include <linux/cache.h> +#include <asm/page.h> + +/* Per processor datastructure. %gs points to it while the kernel runs */ +struct x8664_pda { + struct task_struct *pcurrent; /* 0 Current process */ + unsigned long data_offset; /* 8 Per cpu data offset from linker + address */ + 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 long stack_canary; /* 40 stack canary value */ + /* gcc-ABI: this canary MUST be at + offset 40!!! */ + char *irqstackptr; + short nodenumber; /* number of current node (32k max) */ + short in_bootmem; /* pda lives in bootmem */ + unsigned int __softirq_pending; + unsigned int __nmi_count; /* number of NMI on this CPUs */ + short mmu_state; + short isidle; + struct mm_struct *active_mm; + unsigned apic_timer_irqs; + unsigned irq0_irqs; + unsigned irq_resched_count; + unsigned irq_call_count; + unsigned irq_tlb_count; + unsigned irq_thermal_count; + unsigned irq_threshold_count; + unsigned irq_spurious_count; +} ____cacheline_aligned_in_smp; + +extern struct x8664_pda **_cpu_pda; +extern void pda_init(int); + +#define cpu_pda(i) (_cpu_pda[i]) + +/* + * There is no fast way to get the base address of the PDA, all the accesses + * have to mention %fs/%gs. So it needs to be done this Torvaldian way. + */ +extern void __bad_pda_field(void) __attribute__((noreturn)); + +/* + * proxy_pda doesn't actually exist, but tell gcc it is accessed for + * all PDA accesses so it gets read/write dependencies right. + */ +extern struct x8664_pda _proxy_pda; + +#define pda_offset(field) offsetof(struct x8664_pda, field) + +#define pda_to_op(op, field, val) \ +do { \ + typedef typeof(_proxy_pda.field) T__; \ + if (0) { T__ tmp__; tmp__ = (val); } /* type checking */ \ + switch (sizeof(_proxy_pda.field)) { \ + case 2: \ + asm(op "w %1,%%gs:%c2" : \ + "+m" (_proxy_pda.field) : \ + "ri" ((T__)val), \ + "i"(pda_offset(field))); \ + break; \ + case 4: \ + asm(op "l %1,%%gs:%c2" : \ + "+m" (_proxy_pda.field) : \ + "ri" ((T__)val), \ + "i" (pda_offset(field))); \ + break; \ + case 8: \ + asm(op "q %1,%%gs:%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 2: \ + asm(op "w %%gs:%c1,%0" : \ + "=r" (ret__) : \ + "i" (pda_offset(field)), \ + "m" (_proxy_pda.field)); \ + break; \ + case 4: \ + asm(op "l %%gs:%c1,%0": \ + "=r" (ret__): \ + "i" (pda_offset(field)), \ + "m" (_proxy_pda.field)); \ + break; \ + case 8: \ + asm(op "q %%gs:%c1,%0": \ + "=r" (ret__) : \ + "i" (pda_offset(field)), \ + "m" (_proxy_pda.field)); \ + break; \ + default: \ + __bad_pda_field(); \ + } \ + ret__; \ +}) + +#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) + +/* This is not atomic against other CPUs -- CPU preemption needs to be off */ +#define test_and_clear_bit_pda(bit, field) \ +({ \ + int old__; \ + asm volatile("btr %2,%%gs:%c3\n\tsbbl %0,%0" \ + : "=r" (old__), "+m" (_proxy_pda.field) \ + : "dIr" (bit), "i" (pda_offset(field)) : "memory");\ + old__; \ +}) + +#endif + +#define PDA_STACKOFFSET (5*8) + +#define refresh_stack_canary() write_pda(stack_canary, current->stack_canary) + +#endif /* _ASM_X86_PDA_H */ |