[mirror_ubuntu-eoan-kernel.git] / arch / x86 / include / asm / system.h

#ifndef _ASM_X86_SYSTEM_H
#define _ASM_X86_SYSTEM_H

#include <asm/asm.h>
#include <asm/segment.h>
#include <asm/cpufeature.h>
#include <asm/cmpxchg.h>
#include <asm/nops.h>

#include <linux/kernel.h>
#include <linux/irqflags.h>

/* entries in ARCH_DLINFO: */
#if defined(CONFIG_IA32_EMULATION) || !defined(CONFIG_X86_64)
# define AT_VECTOR_SIZE_ARCH 2
#else /* else it's non-compat x86-64 */
# define AT_VECTOR_SIZE_ARCH 1
#endif

struct task_struct; /* one of the stranger aspects of C forward declarations */
struct task_struct *__switch_to(struct task_struct *prev,
				struct task_struct *next);
struct tss_struct;
void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
		      struct tss_struct *tss);
extern void show_regs_common(void);

#ifdef CONFIG_X86_32

#ifdef CONFIG_CC_STACKPROTECTOR
#define __switch_canary							\
	"movl %P[task_canary](%[next]), %%ebx\n\t"			\
	"movl %%ebx, "__percpu_arg([stack_canary])"\n\t"
#define __switch_canary_oparam						\
	, [stack_canary] "=m" (stack_canary.canary)
#define __switch_canary_iparam						\
	, [task_canary] "i" (offsetof(struct task_struct, stack_canary))
#else	/* CC_STACKPROTECTOR */
#define __switch_canary
#define __switch_canary_oparam
#define __switch_canary_iparam
#endif	/* CC_STACKPROTECTOR */

/*
 * Saving eflags is important. It switches not only IOPL between tasks,
 * it also protects other tasks from NT leaking through sysenter etc.
 */
#define switch_to(prev, next, last)					\
do {									\
	/*								\
	 * Context-switching clobbers all registers, so we clobber	\
	 * them explicitly, via unused output variables.		\
	 * (EAX and EBP is not listed because EBP is saved/restored	\
	 * explicitly for wchan access and EAX is the return value of	\
	 * __switch_to())						\
	 */								\
	unsigned long ebx, ecx, edx, esi, edi;				\
									\
	asm volatile("pushfl\n\t"		/* save    flags */	\
		     "pushl %%ebp\n\t"		/* save    EBP   */	\
		     "movl %%esp,%[prev_sp]\n\t"	/* save    ESP   */ \
		     "movl %[next_sp],%%esp\n\t"	/* restore ESP   */ \
		     "movl $1f,%[prev_ip]\n\t"	/* save    EIP   */	\
		     "pushl %[next_ip]\n\t"	/* restore EIP   */	\
		     __switch_canary					\
		     "jmp __switch_to\n"	/* regparm call  */	\
		     "1:\t"						\
		     "popl %%ebp\n\t"		/* restore EBP   */	\
		     "popfl\n"			/* restore flags */	\
									\
		     /* output parameters */				\
		     : [prev_sp] "=m" (prev->thread.sp),		\
		       [prev_ip] "=m" (prev->thread.ip),		\
		       "=a" (last),					\
									\
		       /* clobbered output registers: */		\
		       "=b" (ebx), "=c" (ecx), "=d" (edx),		\
		       "=S" (esi), "=D" (edi)				\
		       							\
		       __switch_canary_oparam				\
									\
		       /* input parameters: */				\
		     : [next_sp]  "m" (next->thread.sp),		\
		       [next_ip]  "m" (next->thread.ip),		\
		       							\
		       /* regparm parameters for __switch_to(): */	\
		       [prev]     "a" (prev),				\
		       [next]     "d" (next)				\
									\
		       __switch_canary_iparam				\
									\
		     : /* reloaded segment registers */			\
			"memory");					\
} while (0)

/*
 * disable hlt during certain critical i/o operations
 */
#define HAVE_DISABLE_HLT
#else

/* frame pointer must be last for get_wchan */
#define SAVE_CONTEXT    "pushf ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popf\t"

#define __EXTRA_CLOBBER  \
	, "rcx", "rbx", "rdx", "r8", "r9", "r10", "r11", \
	  "r12", "r13", "r14", "r15"

#ifdef CONFIG_CC_STACKPROTECTOR
#define __switch_canary							  \
	"movq %P[task_canary](%%rsi),%%r8\n\t"				  \
	"movq %%r8,"__percpu_arg([gs_canary])"\n\t"
#define __switch_canary_oparam						  \
	, [gs_canary] "=m" (irq_stack_union.stack_canary)
#define __switch_canary_iparam						  \
	, [task_canary] "i" (offsetof(struct task_struct, stack_canary))
#else	/* CC_STACKPROTECTOR */
#define __switch_canary
#define __switch_canary_oparam
#define __switch_canary_iparam
#endif	/* CC_STACKPROTECTOR */

/* Save restore flags to clear handle leaking NT */
#define switch_to(prev, next, last) \
	asm volatile(SAVE_CONTEXT					  \
	     "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */	  \
	     "movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */	  \
	     "call __switch_to\n\t"					  \
	     "movq "__percpu_arg([current_task])",%%rsi\n\t"		  \
	     __switch_canary						  \
	     "movq %P[thread_info](%%rsi),%%r8\n\t"			  \
	     "movq %%rax,%%rdi\n\t" 					  \
	     "testl  %[_tif_fork],%P[ti_flags](%%r8)\n\t"		  \
	     "jnz   ret_from_fork\n\t"					  \
	     RESTORE_CONTEXT						  \
	     : "=a" (last)					  	  \
	       __switch_canary_oparam					  \
	     : [next] "S" (next), [prev] "D" (prev),			  \
	       [threadrsp] "i" (offsetof(struct task_struct, thread.sp)), \
	       [ti_flags] "i" (offsetof(struct thread_info, flags)),	  \
	       [_tif_fork] "i" (_TIF_FORK),			  	  \
	       [thread_info] "i" (offsetof(struct task_struct, stack)),   \
	       [current_task] "m" (current_task)			  \
	       __switch_canary_iparam					  \
	     : "memory", "cc" __EXTRA_CLOBBER)
#endif

#ifdef __KERNEL__

extern void native_load_gs_index(unsigned);

/*
 * Load a segment. Fall back on loading the zero
 * segment if something goes wrong..
 */
#define loadsegment(seg, value)						\
do {									\
	unsigned short __val = (value);					\
									\
	asm volatile("						\n"	\
		     "1:	movl %k0,%%" #seg "		\n"	\
									\
		     ".section .fixup,\"ax\"			\n"	\
		     "2:	xorl %k0,%k0			\n"	\
		     "		jmp 1b				\n"	\
		     ".previous					\n"	\
									\
		     _ASM_EXTABLE(1b, 2b)				\
									\
		     : "+r" (__val) : : "memory");			\
} while (0)

/*
 * Save a segment register away
 */
#define savesegment(seg, value)				\
	asm("mov %%" #seg ",%0":"=r" (value) : : "memory")

/*
 * x86_32 user gs accessors.
 */
#ifdef CONFIG_X86_32
#ifdef CONFIG_X86_32_LAZY_GS
#define get_user_gs(regs)	(u16)({unsigned long v; savesegment(gs, v); v;})
#define set_user_gs(regs, v)	loadsegment(gs, (unsigned long)(v))
#define task_user_gs(tsk)	((tsk)->thread.gs)
#define lazy_save_gs(v)		savesegment(gs, (v))
#define lazy_load_gs(v)		loadsegment(gs, (v))
#else	/* X86_32_LAZY_GS */
#define get_user_gs(regs)	(u16)((regs)->gs)
#define set_user_gs(regs, v)	do { (regs)->gs = (v); } while (0)
#define task_user_gs(tsk)	(task_pt_regs(tsk)->gs)
#define lazy_save_gs(v)		do { } while (0)
#define lazy_load_gs(v)		do { } while (0)
#endif	/* X86_32_LAZY_GS */
#endif	/* X86_32 */

static inline unsigned long get_limit(unsigned long segment)
{
	unsigned long __limit;
	asm("lsll %1,%0" : "=r" (__limit) : "r" (segment));
	return __limit + 1;
}

static inline void native_clts(void)
{
	asm volatile("clts");
}

/*
 * Volatile isn't enough to prevent the compiler from reordering the
 * read/write functions for the control registers and messing everything up.
 * A memory clobber would solve the problem, but would prevent reordering of
 * all loads stores around it, which can hurt performance. Solution is to
 * use a variable and mimic reads and writes to it to enforce serialization
 */
static unsigned long __force_order;

static inline unsigned long native_read_cr0(void)
{
	unsigned long val;
	asm volatile("mov %%cr0,%0\n\t" : "=r" (val), "=m" (__force_order));
	return val;
}

static inline void native_write_cr0(unsigned long val)
{
	asm volatile("mov %0,%%cr0": : "r" (val), "m" (__force_order));
}

static inline unsigned long native_read_cr2(void)
{
	unsigned long val;
	asm volatile("mov %%cr2,%0\n\t" : "=r" (val), "=m" (__force_order));
	return val;
}

static inline void native_write_cr2(unsigned long val)
{
	asm volatile("mov %0,%%cr2": : "r" (val), "m" (__force_order));
}

static inline unsigned long native_read_cr3(void)
{
	unsigned long val;
	asm volatile("mov %%cr3,%0\n\t" : "=r" (val), "=m" (__force_order));
	return val;
}

static inline void native_write_cr3(unsigned long val)
{
	asm volatile("mov %0,%%cr3": : "r" (val), "m" (__force_order));
}

static inline unsigned long native_read_cr4(void)
{
	unsigned long val;
	asm volatile("mov %%cr4,%0\n\t" : "=r" (val), "=m" (__force_order));
	return val;
}

static inline unsigned long native_read_cr4_safe(void)
{
	unsigned long val;
	/* This could fault if %cr4 does not exist. In x86_64, a cr4 always
	 * exists, so it will never fail. */
#ifdef CONFIG_X86_32
	asm volatile("1: mov %%cr4, %0\n"
		     "2:\n"
		     _ASM_EXTABLE(1b, 2b)
		     : "=r" (val), "=m" (__force_order) : "0" (0));
#else
	val = native_read_cr4();
#endif
	return val;
}

static inline void native_write_cr4(unsigned long val)
{
	asm volatile("mov %0,%%cr4": : "r" (val), "m" (__force_order));
}

#ifdef CONFIG_X86_64
static inline unsigned long native_read_cr8(void)
{
	unsigned long cr8;
	asm volatile("movq %%cr8,%0" : "=r" (cr8));
	return cr8;
}

static inline void native_write_cr8(unsigned long val)
{
	asm volatile("movq %0,%%cr8" :: "r" (val) : "memory");
}
#endif

static inline void native_wbinvd(void)
{
	asm volatile("wbinvd": : :"memory");
}

#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#else

static inline unsigned long read_cr0(void)
{
	return native_read_cr0();
}

static inline void write_cr0(unsigned long x)
{
	native_write_cr0(x);
}

static inline unsigned long read_cr2(void)
{
	return native_read_cr2();
}

static inline void write_cr2(unsigned long x)
{
	native_write_cr2(x);
}

static inline unsigned long read_cr3(void)
{
	return native_read_cr3();
}

static inline void write_cr3(unsigned long x)
{
	native_write_cr3(x);
}

static inline unsigned long read_cr4(void)
{
	return native_read_cr4();
}

static inline unsigned long read_cr4_safe(void)
{
	return native_read_cr4_safe();
}

static inline void write_cr4(unsigned long x)
{
	native_write_cr4(x);
}

static inline void wbinvd(void)
{
	native_wbinvd();
}

#ifdef CONFIG_X86_64

static inline unsigned long read_cr8(void)
{
	return native_read_cr8();
}

static inline void write_cr8(unsigned long x)
{
	native_write_cr8(x);
}

static inline void load_gs_index(unsigned selector)
{
	native_load_gs_index(selector);
}

#endif

/* Clear the 'TS' bit */
static inline void clts(void)
{
	native_clts();
}

#endif/* CONFIG_PARAVIRT */

#define stts() write_cr0(read_cr0() | X86_CR0_TS)

#endif /* __KERNEL__ */

static inline void clflush(volatile void *__p)
{
	asm volatile("clflush %0" : "+m" (*(volatile char __force *)__p));
}

#define nop() asm volatile ("nop")

void disable_hlt(void);
void enable_hlt(void);

void cpu_idle_wait(void);

extern unsigned long arch_align_stack(unsigned long sp);
extern void free_init_pages(char *what, unsigned long begin, unsigned long end);

void default_idle(void);
bool set_pm_idle_to_default(void);

void stop_this_cpu(void *dummy);

/*
 * Force strict CPU ordering.
 * And yes, this is required on UP too when we're talking
 * to devices.
 */
#ifdef CONFIG_X86_32
/*
 * Some non-Intel clones support out of order store. wmb() ceases to be a
 * nop for these.
 */
#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
#else
#define mb() 	asm volatile("mfence":::"memory")
#define rmb()	asm volatile("lfence":::"memory")
#define wmb()	asm volatile("sfence" ::: "memory")
#endif

/**
 * read_barrier_depends - Flush all pending reads that subsequents reads
 * depend on.
 *
 * No data-dependent reads from memory-like regions are ever reordered
 * over this barrier.  All reads preceding this primitive are guaranteed
 * to access memory (but not necessarily other CPUs' caches) before any
 * reads following this primitive that depend on the data return by
 * any of the preceding reads.  This primitive is much lighter weight than
 * rmb() on most CPUs, and is never heavier weight than is
 * rmb().
 *
 * These ordering constraints are respected by both the local CPU
 * and the compiler.
 *
 * Ordering is not guaranteed by anything other than these primitives,
 * not even by data dependencies.  See the documentation for
 * memory_barrier() for examples and URLs to more information.
 *
 * For example, the following code would force ordering (the initial
 * value of "a" is zero, "b" is one, and "p" is "&a"):
 *
 * <programlisting>
 *	CPU 0				CPU 1
 *
 *	b = 2;
 *	memory_barrier();
 *	p = &b;				q = p;
 *					read_barrier_depends();
 *					d = *q;
 * </programlisting>
 *
 * because the read of "*q" depends on the read of "p" and these
 * two reads are separated by a read_barrier_depends().  However,
 * the following code, with the same initial values for "a" and "b":
 *
 * <programlisting>
 *	CPU 0				CPU 1
 *
 *	a = 2;
 *	memory_barrier();
 *	b = 3;				y = b;
 *					read_barrier_depends();
 *					x = a;
 * </programlisting>
 *
 * does not enforce ordering, since there is no data dependency between
 * the read of "a" and the read of "b".  Therefore, on some CPUs, such
 * as Alpha, "y" could be set to 3 and "x" to 0.  Use rmb()
 * in cases like this where there are no data dependencies.
 **/

#define read_barrier_depends()	do { } while (0)

#ifdef CONFIG_SMP
#define smp_mb()	mb()
#ifdef CONFIG_X86_PPRO_FENCE
# define smp_rmb()	rmb()
#else
# define smp_rmb()	barrier()
#endif
#ifdef CONFIG_X86_OOSTORE
# define smp_wmb() 	wmb()
#else
# define smp_wmb()	barrier()
#endif
#define smp_read_barrier_depends()	read_barrier_depends()
#define set_mb(var, value) do { (void)xchg(&var, value); } while (0)
#else
#define smp_mb()	barrier()
#define smp_rmb()	barrier()
#define smp_wmb()	barrier()
#define smp_read_barrier_depends()	do { } while (0)
#define set_mb(var, value) do { var = value; barrier(); } while (0)
#endif

/*
 * Stop RDTSC speculation. This is needed when you need to use RDTSC
 * (or get_cycles or vread that possibly accesses the TSC) in a defined
 * code region.
 *
 * (Could use an alternative three way for this if there was one.)
 */
static __always_inline void rdtsc_barrier(void)
{
	alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC);
	alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC);
}

/*
 * We handle most unaligned accesses in hardware.  On the other hand
 * unaligned DMA can be quite expensive on some Nehalem processors.
 *
 * Based on this we disable the IP header alignment in network drivers.
 */
#define NET_IP_ALIGN	0
#endif /* _ASM_X86_SYSTEM_H */
Commit	Line	Data
1965aae3 PA	1	#ifndef _ASM_X86_SYSTEM_H
1965aae3 PA	2	#define _ASM_X86_SYSTEM_H
d8954222 GOC	3
d8954222 GOC	4	#include <asm/asm.h>
d46d7d75 GOC	5	#include <asm/segment.h>
	6	#include <asm/cpufeature.h>
	7	#include <asm/cmpxchg.h>
fde1b3fa	8	#include <asm/nops.h>
d8954222	9
d3ca901f	10	#include <linux/kernel.h>
d46d7d75	11	#include <linux/irqflags.h>
d3ca901f	12
ded9aa0d	13	/* entries in ARCH_DLINFO: */
cf9db6c4	14	#if defined(CONFIG_IA32_EMULATION) \|\| !defined(CONFIG_X86_64)
ded9aa0d	15	# define AT_VECTOR_SIZE_ARCH 2
cf9db6c4	16	#else /* else it's non-compat x86-64 */
ded9aa0d JB	17	# define AT_VECTOR_SIZE_ARCH 1
	18	#endif
	19
0a3b4d15	20	struct task_struct; /* one of the stranger aspects of C forward declarations */
599db4fe HH	21	struct task_struct __switch_to(struct task_struct prev,
599db4fe HH	22	struct task_struct *next);
2fb6b2a0	23	struct tss_struct;
389d1fb1 JF	24	void __switch_to_xtra(struct task_struct prev_p, struct task_struct next_p,
389d1fb1 JF	25	struct tss_struct *tss);
814e2c84	26	extern void show_regs_common(void);
0a3b4d15	27
aab02f0a JS	28	#ifdef CONFIG_X86_32
aab02f0a JS	29
60a5317f TH	30	#ifdef CONFIG_CC_STACKPROTECTOR
60a5317f TH	31	#define __switch_canary \
5c79d2a5 TH	32	"movl %P[task_canary](%[next]), %%ebx\n\t" \
5c79d2a5 TH	33	"movl %%ebx, "__percpu_arg([stack_canary])"\n\t"
60a5317f	34	#define __switch_canary_oparam \
dd17c8f7	35	, [stack_canary] "=m" (stack_canary.canary)
60a5317f	36	#define __switch_canary_iparam \
60a5317f TH	37	, [task_canary] "i" (offsetof(struct task_struct, stack_canary))
	38	#else /* CC_STACKPROTECTOR */
	39	#define __switch_canary
	40	#define __switch_canary_oparam
	41	#define __switch_canary_iparam
	42	#endif /* CC_STACKPROTECTOR */
	43
0a3b4d15 GOC	44	/*
	45	* Saving eflags is important. It switches not only IOPL between tasks,
	46	* it also protects other tasks from NT leaking through sysenter etc.
	47	*/
23b55bd9 IM	48	#define switch_to(prev, next, last) \
23b55bd9 IM	49	do { \
8b6451fe IM	50	/* \
	51	* Context-switching clobbers all registers, so we clobber \
	52	* them explicitly, via unused output variables. \
	53	* (EAX and EBP is not listed because EBP is saved/restored \
	54	* explicitly for wchan access and EAX is the return value of \
	55	* __switch_to()) \
	56	*/ \
	57	unsigned long ebx, ecx, edx, esi, edi; \
23b55bd9	58	\
c5386c20 JP	59	asm volatile("pushfl\n\t" /* save flags */ \
	60	"pushl %%ebp\n\t" /* save EBP */ \
	61	"movl %%esp,%[prev_sp]\n\t" /* save ESP */ \
	62	"movl %[next_sp],%%esp\n\t" /* restore ESP */ \
	63	"movl $1f,%[prev_ip]\n\t" /* save EIP */ \
	64	"pushl %[next_ip]\n\t" /* restore EIP */ \
5c79d2a5	65	__switch_canary \
c5386c20 JP	66	"jmp __switch_to\n" /* regparm call */ \
	67	"1:\t" \
	68	"popl %%ebp\n\t" /* restore EBP */ \
	69	"popfl\n" /* restore flags */ \
23b55bd9	70	\
c5386c20 JP	71	/* output parameters */ \
	72	: [prev_sp] "=m" (prev->thread.sp), \
	73	[prev_ip] "=m" (prev->thread.ip), \
	74	"=a" (last), \
23b55bd9	75	\
c5386c20 JP	76	/* clobbered output registers: */ \
	77	"=b" (ebx), "=c" (ecx), "=d" (edx), \
	78	"=S" (esi), "=D" (edi) \
	79	\
60a5317f TH	80	__switch_canary_oparam \
60a5317f TH	81	\
c5386c20 JP	82	/* input parameters: */ \
	83	: [next_sp] "m" (next->thread.sp), \
	84	[next_ip] "m" (next->thread.ip), \
	85	\
	86	/* regparm parameters for __switch_to(): */ \
	87	[prev] "a" (prev), \
33f8c40a VN	88	[next] "d" (next) \
33f8c40a VN	89	\
60a5317f TH	90	__switch_canary_iparam \
60a5317f TH	91	\
33f8c40a VN	92	: /* reloaded segment registers */ \
33f8c40a VN	93	"memory"); \
0a3b4d15 GOC	94	} while (0)
0a3b4d15 GOC	95
d46d7d75 GOC	96	/*
	97	* disable hlt during certain critical i/o operations
	98	*/
	99	#define HAVE_DISABLE_HLT
96a388de	100	#else
0a3b4d15 GOC	101
	102	/* frame pointer must be last for get_wchan */
	103	#define SAVE_CONTEXT "pushf ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
	104	#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popf\t"
	105
	106	#define __EXTRA_CLOBBER \
	107	, "rcx", "rbx", "rdx", "r8", "r9", "r10", "r11", \
	108	"r12", "r13", "r14", "r15"
	109
b4a8f7a2 TH	110	#ifdef CONFIG_CC_STACKPROTECTOR
	111	#define __switch_canary \
	112	"movq %P[task_canary](%%rsi),%%r8\n\t" \
67e68bde TH	113	"movq %%r8,"__percpu_arg([gs_canary])"\n\t"
67e68bde TH	114	#define __switch_canary_oparam \
dd17c8f7	115	, [gs_canary] "=m" (irq_stack_union.stack_canary)
67e68bde TH	116	#define __switch_canary_iparam \
67e68bde TH	117	, [task_canary] "i" (offsetof(struct task_struct, stack_canary))
b4a8f7a2 TH	118	#else /* CC_STACKPROTECTOR */
b4a8f7a2 TH	119	#define __switch_canary
67e68bde TH	120	#define __switch_canary_oparam
67e68bde TH	121	#define __switch_canary_iparam
b4a8f7a2 TH	122	#endif /* CC_STACKPROTECTOR */
b4a8f7a2 TH	123
0a3b4d15 GOC	124	/* Save restore flags to clear handle leaking NT */
0a3b4d15 GOC	125	#define switch_to(prev, next, last) \
b4a8f7a2	126	asm volatile(SAVE_CONTEXT \
0a3b4d15 GOC	127	"movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \
	128	"movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */ \
	129	"call __switch_to\n\t" \
87b26406	130	"movq "__percpu_arg([current_task])",%%rsi\n\t" \
b4a8f7a2	131	__switch_canary \
0a3b4d15	132	"movq %P[thread_info](%%rsi),%%r8\n\t" \
0a3b4d15	133	"movq %%rax,%%rdi\n\t" \
dd17c8f7	134	"testl %[_tif_fork],%P[ti_flags](%%r8)\n\t" \
7106a5ab	135	"jnz ret_from_fork\n\t" \
0a3b4d15 GOC	136	RESTORE_CONTEXT \
0a3b4d15 GOC	137	: "=a" (last) \
67e68bde	138	__switch_canary_oparam \
0a3b4d15 GOC	139	: [next] "S" (next), [prev] "D" (prev), \
	140	[threadrsp] "i" (offsetof(struct task_struct, thread.sp)), \
	141	[ti_flags] "i" (offsetof(struct thread_info, flags)), \
7106a5ab	142	[_tif_fork] "i" (_TIF_FORK), \
0a3b4d15	143	[thread_info] "i" (offsetof(struct task_struct, stack)), \
dd17c8f7	144	[current_task] "m" (current_task) \
67e68bde	145	__switch_canary_iparam \
0a3b4d15	146	: "memory", "cc" __EXTRA_CLOBBER)
96a388de	147	#endif
d8954222 GOC	148
d8954222 GOC	149	#ifdef __KERNEL__
d8954222	150
9f9d489a	151	extern void native_load_gs_index(unsigned);
d3ca901f	152
a6b46552 GOC	153	/*
	154	* Load a segment. Fall back on loading the zero
	155	* segment if something goes wrong..
	156	*/
64b028b2 IM	157	#define loadsegment(seg, value) \
	158	do { \
	159	unsigned short __val = (value); \
	160	\
	161	asm volatile(" \n" \
	162	"1: movl %k0,%%" #seg " \n" \
	163	\
	164	".section .fixup,\"ax\" \n" \
	165	"2: xorl %k0,%k0 \n" \
	166	" jmp 1b \n" \
	167	".previous \n" \
	168	\
	169	_ASM_EXTABLE(1b, 2b) \
	170	\
	171	: "+r" (__val) : : "memory"); \
79b0379c	172	} while (0)
a6b46552	173
d8954222 GOC	174	/*
	175	* Save a segment register away
	176	*/
c5386c20	177	#define savesegment(seg, value) \
d9fc3fd3	178	asm("mov %%" #seg ",%0":"=r" (value) : : "memory")
d8954222	179
d9a89a26 TH	180	/*
	181	* x86_32 user gs accessors.
	182	*/
	183	#ifdef CONFIG_X86_32
ccbeed3a	184	#ifdef CONFIG_X86_32_LAZY_GS
d9a89a26 TH	185	#define get_user_gs(regs) (u16)({unsigned long v; savesegment(gs, v); v;})
	186	#define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v))
	187	#define task_user_gs(tsk) ((tsk)->thread.gs)
ccbeed3a TH	188	#define lazy_save_gs(v) savesegment(gs, (v))
	189	#define lazy_load_gs(v) loadsegment(gs, (v))
	190	#else /* X86_32_LAZY_GS */
	191	#define get_user_gs(regs) (u16)((regs)->gs)
	192	#define set_user_gs(regs, v) do { (regs)->gs = (v); } while (0)
	193	#define task_user_gs(tsk) (task_pt_regs(tsk)->gs)
	194	#define lazy_save_gs(v) do { } while (0)
	195	#define lazy_load_gs(v) do { } while (0)
	196	#endif /* X86_32_LAZY_GS */
	197	#endif /* X86_32 */
d9a89a26	198
d8954222 GOC	199	static inline unsigned long get_limit(unsigned long segment)
	200	{
	201	unsigned long __limit;
c5386c20 JP	202	asm("lsll %1,%0" : "=r" (__limit) : "r" (segment));
c5386c20 JP	203	return __limit + 1;
d8954222	204	}
d3ca901f GOC	205
	206	static inline void native_clts(void)
	207	{
c5386c20	208	asm volatile("clts");
d3ca901f GOC	209	}
	210
	211	/*
	212	* Volatile isn't enough to prevent the compiler from reordering the
	213	* read/write functions for the control registers and messing everything up.
	214	* A memory clobber would solve the problem, but would prevent reordering of
	215	* all loads stores around it, which can hurt performance. Solution is to
	216	* use a variable and mimic reads and writes to it to enforce serialization
	217	*/
	218	static unsigned long __force_order;
	219
	220	static inline unsigned long native_read_cr0(void)
	221	{
	222	unsigned long val;
c5386c20	223	asm volatile("mov %%cr0,%0\n\t" : "=r" (val), "=m" (__force_order));
d3ca901f GOC	224	return val;
	225	}
	226
	227	static inline void native_write_cr0(unsigned long val)
	228	{
c5386c20	229	asm volatile("mov %0,%%cr0": : "r" (val), "m" (__force_order));
d3ca901f GOC	230	}
	231
	232	static inline unsigned long native_read_cr2(void)
	233	{
	234	unsigned long val;
c5386c20	235	asm volatile("mov %%cr2,%0\n\t" : "=r" (val), "=m" (__force_order));
d3ca901f GOC	236	return val;
	237	}
	238
	239	static inline void native_write_cr2(unsigned long val)
	240	{
c5386c20	241	asm volatile("mov %0,%%cr2": : "r" (val), "m" (__force_order));
d3ca901f GOC	242	}
	243
	244	static inline unsigned long native_read_cr3(void)
	245	{
	246	unsigned long val;
c5386c20	247	asm volatile("mov %%cr3,%0\n\t" : "=r" (val), "=m" (__force_order));
d3ca901f GOC	248	return val;
	249	}
	250
	251	static inline void native_write_cr3(unsigned long val)
	252	{
c5386c20	253	asm volatile("mov %0,%%cr3": : "r" (val), "m" (__force_order));
d3ca901f GOC	254	}
	255
	256	static inline unsigned long native_read_cr4(void)
	257	{
	258	unsigned long val;
c5386c20	259	asm volatile("mov %%cr4,%0\n\t" : "=r" (val), "=m" (__force_order));
d3ca901f GOC	260	return val;
	261	}
	262
	263	static inline unsigned long native_read_cr4_safe(void)
	264	{
	265	unsigned long val;
	266	/* This could fault if %cr4 does not exist. In x86_64, a cr4 always
	267	* exists, so it will never fail. */
	268	#ifdef CONFIG_X86_32
88976ee1 PA	269	asm volatile("1: mov %%cr4, %0\n"
88976ee1 PA	270	"2:\n"
c5386c20	271	_ASM_EXTABLE(1b, 2b)
88976ee1	272	: "=r" (val), "=m" (__force_order) : "0" (0));
d3ca901f GOC	273	#else
	274	val = native_read_cr4();
	275	#endif
	276	return val;
	277	}
	278
	279	static inline void native_write_cr4(unsigned long val)
	280	{
c5386c20	281	asm volatile("mov %0,%%cr4": : "r" (val), "m" (__force_order));
d3ca901f GOC	282	}
d3ca901f GOC	283
94ea03cd GOC	284	#ifdef CONFIG_X86_64
	285	static inline unsigned long native_read_cr8(void)
	286	{
	287	unsigned long cr8;
	288	asm volatile("movq %%cr8,%0" : "=r" (cr8));
	289	return cr8;
	290	}
	291
	292	static inline void native_write_cr8(unsigned long val)
	293	{
	294	asm volatile("movq %0,%%cr8" :: "r" (val) : "memory");
	295	}
	296	#endif
	297
d3ca901f GOC	298	static inline void native_wbinvd(void)
	299	{
	300	asm volatile("wbinvd": : :"memory");
	301	}
c5386c20	302
d3ca901f GOC	303	#ifdef CONFIG_PARAVIRT
	304	#include <asm/paravirt.h>
	305	#else
15d6aba2 AK	306
	307	static inline unsigned long read_cr0(void)
	308	{
	309	return native_read_cr0();
	310	}
	311
	312	static inline void write_cr0(unsigned long x)
	313	{
	314	native_write_cr0(x);
	315	}
	316
	317	static inline unsigned long read_cr2(void)
	318	{
	319	return native_read_cr2();
	320	}
	321
	322	static inline void write_cr2(unsigned long x)
	323	{
	324	native_write_cr2(x);
	325	}
	326
	327	static inline unsigned long read_cr3(void)
	328	{
	329	return native_read_cr3();
	330	}
	331
	332	static inline void write_cr3(unsigned long x)
	333	{
	334	native_write_cr3(x);
	335	}
	336
	337	static inline unsigned long read_cr4(void)
	338	{
	339	return native_read_cr4();
	340	}
	341
	342	static inline unsigned long read_cr4_safe(void)
	343	{
	344	return native_read_cr4_safe();
	345	}
	346
	347	static inline void write_cr4(unsigned long x)
	348	{
	349	native_write_cr4(x);
	350	}
	351
	352	static inline void wbinvd(void)
	353	{
	354	native_wbinvd();
	355	}
	356
d46d7d75	357	#ifdef CONFIG_X86_64
15d6aba2 AK	358
	359	static inline unsigned long read_cr8(void)
	360	{
	361	return native_read_cr8();
	362	}
	363
	364	static inline void write_cr8(unsigned long x)
	365	{
	366	native_write_cr8(x);
	367	}
	368
	369	static inline void load_gs_index(unsigned selector)
	370	{
	371	native_load_gs_index(selector);
	372	}
	373
d46d7d75 GOC	374	#endif
d46d7d75 GOC	375
d3ca901f	376	/* Clear the 'TS' bit */
15d6aba2 AK	377	static inline void clts(void)
	378	{
	379	native_clts();
	380	}
d3ca901f GOC	381
	382	#endif/* CONFIG_PARAVIRT */
	383
4e09e21c	384	#define stts() write_cr0(read_cr0() \| X86_CR0_TS)
d3ca901f	385
d8954222 GOC	386	#endif /* __KERNEL__ */
d8954222 GOC	387
84fb144b	388	static inline void clflush(volatile void *__p)
d8954222	389	{
84fb144b	390	asm volatile("clflush %0" : "+m" ((volatile char __force )__p));
d8954222 GOC	391	}
d8954222 GOC	392
c5386c20	393	#define nop() asm volatile ("nop")
d8954222 GOC	394
	395	void disable_hlt(void);
	396	void enable_hlt(void);
	397
d8954222 GOC	398	void cpu_idle_wait(void);
	399
	400	extern unsigned long arch_align_stack(unsigned long sp);
	401	extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
	402
	403	void default_idle(void);
e5fd47bf	404	bool set_pm_idle_to_default(void);
d8954222	405
d3ec5cae IV	406	void stop_this_cpu(void *dummy);
d3ec5cae IV	407
833d8469 GOC	408	/*
	409	* Force strict CPU ordering.
	410	* And yes, this is required on UP too when we're talking
	411	* to devices.
	412	*/
	413	#ifdef CONFIG_X86_32
	414	/*
0d7a1819	415	* Some non-Intel clones support out of order store. wmb() ceases to be a
833d8469 GOC	416	* nop for these.
	417	*/
	418	#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
	419	#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
	420	#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
	421	#else
	422	#define mb() asm volatile("mfence":::"memory")
	423	#define rmb() asm volatile("lfence":::"memory")
	424	#define wmb() asm volatile("sfence" ::: "memory")
	425	#endif
	426
	427	/**
	428	* read_barrier_depends - Flush all pending reads that subsequents reads
	429	* depend on.
	430	*
	431	* No data-dependent reads from memory-like regions are ever reordered
	432	* over this barrier. All reads preceding this primitive are guaranteed
	433	* to access memory (but not necessarily other CPUs' caches) before any
	434	* reads following this primitive that depend on the data return by
	435	* any of the preceding reads. This primitive is much lighter weight than
	436	* rmb() on most CPUs, and is never heavier weight than is
	437	* rmb().
	438	*
	439	* These ordering constraints are respected by both the local CPU
	440	* and the compiler.
	441	*
	442	* Ordering is not guaranteed by anything other than these primitives,
	443	* not even by data dependencies. See the documentation for
	444	* memory_barrier() for examples and URLs to more information.
	445	*
	446	* For example, the following code would force ordering (the initial
	447	* value of "a" is zero, "b" is one, and "p" is "&a"):
	448	*
	449	* <programlisting>
	450	* CPU 0 CPU 1
	451	*
	452	* b = 2;
	453	* memory_barrier();
	454	* p = &b; q = p;
	455	* read_barrier_depends();
	456	* d = *q;
	457	* </programlisting>
	458	*
	459	* because the read of "*q" depends on the read of "p" and these
	460	* two reads are separated by a read_barrier_depends(). However,
	461	* the following code, with the same initial values for "a" and "b":
	462	*
	463	* <programlisting>
	464	* CPU 0 CPU 1
	465	*
	466	* a = 2;
	467	* memory_barrier();
	468	* b = 3; y = b;
	469	* read_barrier_depends();
	470	* x = a;
	471	* </programlisting>
	472	*
	473	* does not enforce ordering, since there is no data dependency between
	474	* the read of "a" and the read of "b". Therefore, on some CPUs, such
	475	* as Alpha, "y" could be set to 3 and "x" to 0. Use rmb()
	476	* in cases like this where there are no data dependencies.
	477	**/
	478
	479	#define read_barrier_depends() do { } while (0)
480
481	#ifdef CONFIG_SMP
482	#define smp_mb() mb()
483	#ifdef CONFIG_X86_PPRO_FENCE
484	# define smp_rmb() rmb()
485	#else
486	# define smp_rmb() barrier()
487	#endif
488	#ifdef CONFIG_X86_OOSTORE
489	# define smp_wmb() wmb()
490	#else
491	# define smp_wmb() barrier()
492	#endif
493	#define smp_read_barrier_depends() read_barrier_depends()
c5386c20	494	#define set_mb(var, value) do { (void)xchg(&var, value); } while (0)
833d8469 GOC	495	#else
	496	#define smp_mb() barrier()
	497	#define smp_rmb() barrier()
	498	#define smp_wmb() barrier()
	499	#define smp_read_barrier_depends() do { } while (0)
	500	#define set_mb(var, value) do { var = value; barrier(); } while (0)
	501	#endif
	502
fde1b3fa AK	503	/*
	504	* Stop RDTSC speculation. This is needed when you need to use RDTSC
	505	* (or get_cycles or vread that possibly accesses the TSC) in a defined
	506	* code region.
	507	*
	508	* (Could use an alternative three way for this if there was one.)
	509	*/
12448293	510	static __always_inline void rdtsc_barrier(void)
fde1b3fa AK	511	{
	512	alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC);
	513	alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC);
	514	}
833d8469	515
ea812ca1 AD	516	/*
	517	* We handle most unaligned accesses in hardware. On the other hand
	518	* unaligned DMA can be quite expensive on some Nehalem processors.
	519	*
	520	* Based on this we disable the IP header alignment in network drivers.
	521	*/
	522	#define NET_IP_ALIGN 0
1965aae3	523	#endif /* _ASM_X86_SYSTEM_H */