forked from luck/tmp_suning_uos_patched
9446868b53
When another interrupt happens in exit_idle the exit idle notifier could be called an incorrect number of times. Add a test_and_clear_bit_pda and use it handle the bit atomically against interrupts to avoid this. Pointed out by Stephane Eranian Signed-off-by: Andi Kleen <ak@suse.de>
126 lines
3.6 KiB
C
126 lines
3.6 KiB
C
#ifndef X86_64_PDA_H
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#define X86_64_PDA_H
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#ifndef __ASSEMBLY__
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#include <linux/stddef.h>
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#include <linux/types.h>
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#include <linux/cache.h>
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#include <asm/page.h>
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/* Per processor datastructure. %gs points to it while the kernel runs */
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struct x8664_pda {
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struct task_struct *pcurrent; /* 0 Current process */
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unsigned long data_offset; /* 8 Per cpu data offset from linker
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address */
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unsigned long kernelstack; /* 16 top of kernel stack for current */
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unsigned long oldrsp; /* 24 user rsp for system call */
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int irqcount; /* 32 Irq nesting counter. Starts with -1 */
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int cpunumber; /* 36 Logical CPU number */
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#ifdef CONFIG_CC_STACKPROTECTOR
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unsigned long stack_canary; /* 40 stack canary value */
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/* gcc-ABI: this canary MUST be at
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offset 40!!! */
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#endif
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char *irqstackptr;
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int nodenumber; /* number of current node */
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unsigned int __softirq_pending;
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unsigned int __nmi_count; /* number of NMI on this CPUs */
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short mmu_state;
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short isidle;
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struct mm_struct *active_mm;
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unsigned apic_timer_irqs;
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} ____cacheline_aligned_in_smp;
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extern struct x8664_pda *_cpu_pda[];
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extern struct x8664_pda boot_cpu_pda[];
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#define cpu_pda(i) (_cpu_pda[i])
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/*
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* There is no fast way to get the base address of the PDA, all the accesses
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* have to mention %fs/%gs. So it needs to be done this Torvaldian way.
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*/
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extern void __bad_pda_field(void) __attribute__((noreturn));
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/*
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* proxy_pda doesn't actually exist, but tell gcc it is accessed for
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* all PDA accesses so it gets read/write dependencies right.
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*/
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extern struct x8664_pda _proxy_pda;
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#define pda_offset(field) offsetof(struct x8664_pda, field)
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#define pda_to_op(op,field,val) do { \
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typedef typeof(_proxy_pda.field) T__; \
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if (0) { T__ tmp__; tmp__ = (val); } /* type checking */ \
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switch (sizeof(_proxy_pda.field)) { \
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case 2: \
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asm(op "w %1,%%gs:%c2" : \
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"+m" (_proxy_pda.field) : \
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"ri" ((T__)val), \
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"i"(pda_offset(field))); \
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break; \
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case 4: \
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asm(op "l %1,%%gs:%c2" : \
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"+m" (_proxy_pda.field) : \
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"ri" ((T__)val), \
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"i" (pda_offset(field))); \
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break; \
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case 8: \
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asm(op "q %1,%%gs:%c2": \
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"+m" (_proxy_pda.field) : \
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"ri" ((T__)val), \
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"i"(pda_offset(field))); \
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break; \
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default: \
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__bad_pda_field(); \
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} \
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} while (0)
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#define pda_from_op(op,field) ({ \
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typeof(_proxy_pda.field) ret__; \
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switch (sizeof(_proxy_pda.field)) { \
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case 2: \
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asm(op "w %%gs:%c1,%0" : \
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"=r" (ret__) : \
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"i" (pda_offset(field)), \
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"m" (_proxy_pda.field)); \
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break; \
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case 4: \
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asm(op "l %%gs:%c1,%0": \
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"=r" (ret__): \
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"i" (pda_offset(field)), \
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"m" (_proxy_pda.field)); \
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break; \
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case 8: \
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asm(op "q %%gs:%c1,%0": \
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"=r" (ret__) : \
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"i" (pda_offset(field)), \
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"m" (_proxy_pda.field)); \
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break; \
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default: \
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__bad_pda_field(); \
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} \
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ret__; })
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#define read_pda(field) pda_from_op("mov",field)
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#define write_pda(field,val) pda_to_op("mov",field,val)
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#define add_pda(field,val) pda_to_op("add",field,val)
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#define sub_pda(field,val) pda_to_op("sub",field,val)
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#define or_pda(field,val) pda_to_op("or",field,val)
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/* This is not atomic against other CPUs -- CPU preemption needs to be off */
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#define test_and_clear_bit_pda(bit,field) ({ \
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int old__; \
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asm volatile("btr %2,%%gs:%c3\n\tsbbl %0,%0" \
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: "=r" (old__), "+m" (_proxy_pda.field) \
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: "dIr" (bit), "i" (pda_offset(field)) : "memory"); \
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old__; \
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})
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#endif
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#define PDA_STACKOFFSET (5*8)
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#endif
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