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Glauber de Oliveira Costad8954222008-01-30 13:31:08 +01001#ifndef _ASM_X86_SYSTEM_H_
2#define _ASM_X86_SYSTEM_H_
3
4#include <asm/asm.h>
Glauber de Oliveira Costad46d7d72008-01-30 13:31:08 +01005#include <asm/segment.h>
6#include <asm/cpufeature.h>
7#include <asm/cmpxchg.h>
Andi Kleenfde1b3f2008-01-30 13:32:38 +01008#include <asm/nops.h>
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +01009
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +010010#include <linux/kernel.h>
Glauber de Oliveira Costad46d7d72008-01-30 13:31:08 +010011#include <linux/irqflags.h>
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +010012
Jan Beulichded9aa02008-01-30 13:31:24 +010013/* entries in ARCH_DLINFO: */
14#ifdef CONFIG_IA32_EMULATION
15# define AT_VECTOR_SIZE_ARCH 2
16#else
17# define AT_VECTOR_SIZE_ARCH 1
18#endif
19
Thomas Gleixner96a388d2007-10-11 11:20:03 +020020#ifdef CONFIG_X86_32
Glauber de Oliveira Costa0a3b4d12008-01-30 13:31:08 +010021
22struct task_struct; /* one of the stranger aspects of C forward declarations */
Harvey Harrison599db4f2008-02-04 16:48:03 +010023struct task_struct *__switch_to(struct task_struct *prev,
24 struct task_struct *next);
Glauber de Oliveira Costa0a3b4d12008-01-30 13:31:08 +010025
26/*
27 * Saving eflags is important. It switches not only IOPL between tasks,
28 * it also protects other tasks from NT leaking through sysenter etc.
29 */
Ingo Molnar23b55bd2008-03-05 10:24:37 +010030#define switch_to(prev, next, last) \
31do { \
Ingo Molnar8b6451f2008-03-05 10:46:38 +010032 /* \
33 * Context-switching clobbers all registers, so we clobber \
34 * them explicitly, via unused output variables. \
35 * (EAX and EBP is not listed because EBP is saved/restored \
36 * explicitly for wchan access and EAX is the return value of \
37 * __switch_to()) \
38 */ \
39 unsigned long ebx, ecx, edx, esi, edi; \
Ingo Molnar23b55bd2008-03-05 10:24:37 +010040 \
Joe Perchesc5386c22008-03-23 01:03:39 -070041 asm volatile("pushfl\n\t" /* save flags */ \
42 "pushl %%ebp\n\t" /* save EBP */ \
43 "movl %%esp,%[prev_sp]\n\t" /* save ESP */ \
44 "movl %[next_sp],%%esp\n\t" /* restore ESP */ \
45 "movl $1f,%[prev_ip]\n\t" /* save EIP */ \
46 "pushl %[next_ip]\n\t" /* restore EIP */ \
47 "jmp __switch_to\n" /* regparm call */ \
48 "1:\t" \
49 "popl %%ebp\n\t" /* restore EBP */ \
50 "popfl\n" /* restore flags */ \
Ingo Molnar23b55bd2008-03-05 10:24:37 +010051 \
Joe Perchesc5386c22008-03-23 01:03:39 -070052 /* output parameters */ \
53 : [prev_sp] "=m" (prev->thread.sp), \
54 [prev_ip] "=m" (prev->thread.ip), \
55 "=a" (last), \
Ingo Molnar23b55bd2008-03-05 10:24:37 +010056 \
Joe Perchesc5386c22008-03-23 01:03:39 -070057 /* clobbered output registers: */ \
58 "=b" (ebx), "=c" (ecx), "=d" (edx), \
59 "=S" (esi), "=D" (edi) \
60 \
61 /* input parameters: */ \
62 : [next_sp] "m" (next->thread.sp), \
63 [next_ip] "m" (next->thread.ip), \
64 \
65 /* regparm parameters for __switch_to(): */ \
66 [prev] "a" (prev), \
67 [next] "d" (next)); \
Glauber de Oliveira Costa0a3b4d12008-01-30 13:31:08 +010068} while (0)
69
Glauber de Oliveira Costad46d7d72008-01-30 13:31:08 +010070/*
71 * disable hlt during certain critical i/o operations
72 */
73#define HAVE_DISABLE_HLT
Thomas Gleixner96a388d2007-10-11 11:20:03 +020074#else
Glauber de Oliveira Costa0a3b4d12008-01-30 13:31:08 +010075#define __SAVE(reg, offset) "movq %%" #reg ",(14-" #offset ")*8(%%rsp)\n\t"
76#define __RESTORE(reg, offset) "movq (14-" #offset ")*8(%%rsp),%%" #reg "\n\t"
77
78/* frame pointer must be last for get_wchan */
79#define SAVE_CONTEXT "pushf ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
80#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popf\t"
81
82#define __EXTRA_CLOBBER \
83 , "rcx", "rbx", "rdx", "r8", "r9", "r10", "r11", \
84 "r12", "r13", "r14", "r15"
85
86/* Save restore flags to clear handle leaking NT */
87#define switch_to(prev, next, last) \
Jan Beulichded9aa02008-01-30 13:31:24 +010088 asm volatile(SAVE_CONTEXT \
Glauber de Oliveira Costa0a3b4d12008-01-30 13:31:08 +010089 "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \
90 "movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */ \
91 "call __switch_to\n\t" \
92 ".globl thread_return\n" \
93 "thread_return:\n\t" \
94 "movq %%gs:%P[pda_pcurrent],%%rsi\n\t" \
95 "movq %P[thread_info](%%rsi),%%r8\n\t" \
96 LOCK_PREFIX "btr %[tif_fork],%P[ti_flags](%%r8)\n\t" \
97 "movq %%rax,%%rdi\n\t" \
98 "jc ret_from_fork\n\t" \
99 RESTORE_CONTEXT \
100 : "=a" (last) \
101 : [next] "S" (next), [prev] "D" (prev), \
102 [threadrsp] "i" (offsetof(struct task_struct, thread.sp)), \
103 [ti_flags] "i" (offsetof(struct thread_info, flags)), \
104 [tif_fork] "i" (TIF_FORK), \
105 [thread_info] "i" (offsetof(struct task_struct, stack)), \
106 [pda_pcurrent] "i" (offsetof(struct x8664_pda, pcurrent)) \
107 : "memory", "cc" __EXTRA_CLOBBER)
Thomas Gleixner96a388d2007-10-11 11:20:03 +0200108#endif
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +0100109
110#ifdef __KERNEL__
111#define _set_base(addr, base) do { unsigned long __pr; \
112__asm__ __volatile__ ("movw %%dx,%1\n\t" \
113 "rorl $16,%%edx\n\t" \
114 "movb %%dl,%2\n\t" \
115 "movb %%dh,%3" \
116 :"=&d" (__pr) \
117 :"m" (*((addr)+2)), \
118 "m" (*((addr)+4)), \
119 "m" (*((addr)+7)), \
120 "0" (base) \
121 ); } while (0)
122
123#define _set_limit(addr, limit) do { unsigned long __lr; \
124__asm__ __volatile__ ("movw %%dx,%1\n\t" \
125 "rorl $16,%%edx\n\t" \
126 "movb %2,%%dh\n\t" \
127 "andb $0xf0,%%dh\n\t" \
128 "orb %%dh,%%dl\n\t" \
129 "movb %%dl,%2" \
130 :"=&d" (__lr) \
131 :"m" (*(addr)), \
132 "m" (*((addr)+6)), \
133 "0" (limit) \
134 ); } while (0)
135
136#define set_base(ldt, base) _set_base(((char *)&(ldt)) , (base))
137#define set_limit(ldt, limit) _set_limit(((char *)&(ldt)) , ((limit)-1))
138
Jeremy Fitzhardinge9f9d4892008-06-25 00:19:32 -0400139extern void native_load_gs_index(unsigned);
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100140
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +0100141/*
Glauber de Oliveira Costaa6b46552008-01-30 13:31:08 +0100142 * Load a segment. Fall back on loading the zero
143 * segment if something goes wrong..
144 */
145#define loadsegment(seg, value) \
146 asm volatile("\n" \
Joe Perchesc5386c22008-03-23 01:03:39 -0700147 "1:\t" \
148 "movl %k0,%%" #seg "\n" \
149 "2:\n" \
150 ".section .fixup,\"ax\"\n" \
151 "3:\t" \
152 "movl %k1, %%" #seg "\n\t" \
153 "jmp 2b\n" \
154 ".previous\n" \
155 _ASM_EXTABLE(1b,3b) \
Jeremy Fitzhardinged338c732008-06-25 00:18:58 -0400156 : :"r" (value), "r" (0) : "memory")
Glauber de Oliveira Costaa6b46552008-01-30 13:31:08 +0100157
158
159/*
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +0100160 * Save a segment register away
161 */
Joe Perchesc5386c22008-03-23 01:03:39 -0700162#define savesegment(seg, value) \
Ingo Molnard9fc3fd2008-07-11 19:41:19 +0200163 asm("mov %%" #seg ",%0":"=r" (value) : : "memory")
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +0100164
165static inline unsigned long get_limit(unsigned long segment)
166{
167 unsigned long __limit;
Joe Perchesc5386c22008-03-23 01:03:39 -0700168 asm("lsll %1,%0" : "=r" (__limit) : "r" (segment));
169 return __limit + 1;
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +0100170}
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100171
172static inline void native_clts(void)
173{
Joe Perchesc5386c22008-03-23 01:03:39 -0700174 asm volatile("clts");
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100175}
176
177/*
178 * Volatile isn't enough to prevent the compiler from reordering the
179 * read/write functions for the control registers and messing everything up.
180 * A memory clobber would solve the problem, but would prevent reordering of
181 * all loads stores around it, which can hurt performance. Solution is to
182 * use a variable and mimic reads and writes to it to enforce serialization
183 */
184static unsigned long __force_order;
185
186static inline unsigned long native_read_cr0(void)
187{
188 unsigned long val;
Joe Perchesc5386c22008-03-23 01:03:39 -0700189 asm volatile("mov %%cr0,%0\n\t" : "=r" (val), "=m" (__force_order));
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100190 return val;
191}
192
193static inline void native_write_cr0(unsigned long val)
194{
Joe Perchesc5386c22008-03-23 01:03:39 -0700195 asm volatile("mov %0,%%cr0": : "r" (val), "m" (__force_order));
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100196}
197
198static inline unsigned long native_read_cr2(void)
199{
200 unsigned long val;
Joe Perchesc5386c22008-03-23 01:03:39 -0700201 asm volatile("mov %%cr2,%0\n\t" : "=r" (val), "=m" (__force_order));
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100202 return val;
203}
204
205static inline void native_write_cr2(unsigned long val)
206{
Joe Perchesc5386c22008-03-23 01:03:39 -0700207 asm volatile("mov %0,%%cr2": : "r" (val), "m" (__force_order));
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100208}
209
210static inline unsigned long native_read_cr3(void)
211{
212 unsigned long val;
Joe Perchesc5386c22008-03-23 01:03:39 -0700213 asm volatile("mov %%cr3,%0\n\t" : "=r" (val), "=m" (__force_order));
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100214 return val;
215}
216
217static inline void native_write_cr3(unsigned long val)
218{
Joe Perchesc5386c22008-03-23 01:03:39 -0700219 asm volatile("mov %0,%%cr3": : "r" (val), "m" (__force_order));
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100220}
221
222static inline unsigned long native_read_cr4(void)
223{
224 unsigned long val;
Joe Perchesc5386c22008-03-23 01:03:39 -0700225 asm volatile("mov %%cr4,%0\n\t" : "=r" (val), "=m" (__force_order));
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100226 return val;
227}
228
229static inline unsigned long native_read_cr4_safe(void)
230{
231 unsigned long val;
232 /* This could fault if %cr4 does not exist. In x86_64, a cr4 always
233 * exists, so it will never fail. */
234#ifdef CONFIG_X86_32
H. Peter Anvin88976ee2008-02-04 16:47:58 +0100235 asm volatile("1: mov %%cr4, %0\n"
236 "2:\n"
Joe Perchesc5386c22008-03-23 01:03:39 -0700237 _ASM_EXTABLE(1b, 2b)
H. Peter Anvin88976ee2008-02-04 16:47:58 +0100238 : "=r" (val), "=m" (__force_order) : "0" (0));
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100239#else
240 val = native_read_cr4();
241#endif
242 return val;
243}
244
245static inline void native_write_cr4(unsigned long val)
246{
Joe Perchesc5386c22008-03-23 01:03:39 -0700247 asm volatile("mov %0,%%cr4": : "r" (val), "m" (__force_order));
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100248}
249
Glauber de Oliveira Costa94ea03c2008-01-30 13:33:19 +0100250#ifdef CONFIG_X86_64
251static inline unsigned long native_read_cr8(void)
252{
253 unsigned long cr8;
254 asm volatile("movq %%cr8,%0" : "=r" (cr8));
255 return cr8;
256}
257
258static inline void native_write_cr8(unsigned long val)
259{
260 asm volatile("movq %0,%%cr8" :: "r" (val) : "memory");
261}
262#endif
263
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100264static inline void native_wbinvd(void)
265{
266 asm volatile("wbinvd": : :"memory");
267}
Joe Perchesc5386c22008-03-23 01:03:39 -0700268
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100269#ifdef CONFIG_PARAVIRT
270#include <asm/paravirt.h>
271#else
272#define read_cr0() (native_read_cr0())
273#define write_cr0(x) (native_write_cr0(x))
274#define read_cr2() (native_read_cr2())
275#define write_cr2(x) (native_write_cr2(x))
276#define read_cr3() (native_read_cr3())
277#define write_cr3(x) (native_write_cr3(x))
278#define read_cr4() (native_read_cr4())
279#define read_cr4_safe() (native_read_cr4_safe())
280#define write_cr4(x) (native_write_cr4(x))
281#define wbinvd() (native_wbinvd())
Glauber de Oliveira Costad46d7d72008-01-30 13:31:08 +0100282#ifdef CONFIG_X86_64
Glauber de Oliveira Costa94ea03c2008-01-30 13:33:19 +0100283#define read_cr8() (native_read_cr8())
284#define write_cr8(x) (native_write_cr8(x))
Jeremy Fitzhardinge9f9d4892008-06-25 00:19:32 -0400285#define load_gs_index native_load_gs_index
Glauber de Oliveira Costad46d7d72008-01-30 13:31:08 +0100286#endif
287
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100288/* Clear the 'TS' bit */
289#define clts() (native_clts())
290
291#endif/* CONFIG_PARAVIRT */
292
Jeremy Fitzhardinge4e09e212008-05-26 23:31:03 +0100293#define stts() write_cr0(read_cr0() | X86_CR0_TS)
Glauber de Oliveira Costad3ca9012008-01-30 13:31:08 +0100294
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +0100295#endif /* __KERNEL__ */
296
H. Peter Anvin84fb1442008-02-04 16:48:00 +0100297static inline void clflush(volatile void *__p)
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +0100298{
H. Peter Anvin84fb1442008-02-04 16:48:00 +0100299 asm volatile("clflush %0" : "+m" (*(volatile char __force *)__p));
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +0100300}
301
Joe Perchesc5386c22008-03-23 01:03:39 -0700302#define nop() asm volatile ("nop")
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +0100303
304void disable_hlt(void);
305void enable_hlt(void);
306
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +0100307void cpu_idle_wait(void);
308
309extern unsigned long arch_align_stack(unsigned long sp);
310extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
311
312void default_idle(void);
313
Glauber de Oliveira Costa833d8462008-01-30 13:31:08 +0100314/*
315 * Force strict CPU ordering.
316 * And yes, this is required on UP too when we're talking
317 * to devices.
318 */
319#ifdef CONFIG_X86_32
320/*
Pavel Machek0d7a1812008-03-03 12:49:09 +0100321 * Some non-Intel clones support out of order store. wmb() ceases to be a
Glauber de Oliveira Costa833d8462008-01-30 13:31:08 +0100322 * nop for these.
323 */
324#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
325#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
326#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
327#else
328#define mb() asm volatile("mfence":::"memory")
329#define rmb() asm volatile("lfence":::"memory")
330#define wmb() asm volatile("sfence" ::: "memory")
331#endif
332
333/**
334 * read_barrier_depends - Flush all pending reads that subsequents reads
335 * depend on.
336 *
337 * No data-dependent reads from memory-like regions are ever reordered
338 * over this barrier. All reads preceding this primitive are guaranteed
339 * to access memory (but not necessarily other CPUs' caches) before any
340 * reads following this primitive that depend on the data return by
341 * any of the preceding reads. This primitive is much lighter weight than
342 * rmb() on most CPUs, and is never heavier weight than is
343 * rmb().
344 *
345 * These ordering constraints are respected by both the local CPU
346 * and the compiler.
347 *
348 * Ordering is not guaranteed by anything other than these primitives,
349 * not even by data dependencies. See the documentation for
350 * memory_barrier() for examples and URLs to more information.
351 *
352 * For example, the following code would force ordering (the initial
353 * value of "a" is zero, "b" is one, and "p" is "&a"):
354 *
355 * <programlisting>
356 * CPU 0 CPU 1
357 *
358 * b = 2;
359 * memory_barrier();
360 * p = &b; q = p;
361 * read_barrier_depends();
362 * d = *q;
363 * </programlisting>
364 *
365 * because the read of "*q" depends on the read of "p" and these
366 * two reads are separated by a read_barrier_depends(). However,
367 * the following code, with the same initial values for "a" and "b":
368 *
369 * <programlisting>
370 * CPU 0 CPU 1
371 *
372 * a = 2;
373 * memory_barrier();
374 * b = 3; y = b;
375 * read_barrier_depends();
376 * x = a;
377 * </programlisting>
378 *
379 * does not enforce ordering, since there is no data dependency between
380 * the read of "a" and the read of "b". Therefore, on some CPUs, such
381 * as Alpha, "y" could be set to 3 and "x" to 0. Use rmb()
382 * in cases like this where there are no data dependencies.
383 **/
384
385#define read_barrier_depends() do { } while (0)
386
387#ifdef CONFIG_SMP
388#define smp_mb() mb()
389#ifdef CONFIG_X86_PPRO_FENCE
390# define smp_rmb() rmb()
391#else
392# define smp_rmb() barrier()
393#endif
394#ifdef CONFIG_X86_OOSTORE
395# define smp_wmb() wmb()
396#else
397# define smp_wmb() barrier()
398#endif
399#define smp_read_barrier_depends() read_barrier_depends()
Joe Perchesc5386c22008-03-23 01:03:39 -0700400#define set_mb(var, value) do { (void)xchg(&var, value); } while (0)
Glauber de Oliveira Costa833d8462008-01-30 13:31:08 +0100401#else
402#define smp_mb() barrier()
403#define smp_rmb() barrier()
404#define smp_wmb() barrier()
405#define smp_read_barrier_depends() do { } while (0)
406#define set_mb(var, value) do { var = value; barrier(); } while (0)
407#endif
408
Andi Kleenfde1b3f2008-01-30 13:32:38 +0100409/*
410 * Stop RDTSC speculation. This is needed when you need to use RDTSC
411 * (or get_cycles or vread that possibly accesses the TSC) in a defined
412 * code region.
413 *
414 * (Could use an alternative three way for this if there was one.)
415 */
416static inline void rdtsc_barrier(void)
417{
418 alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC);
419 alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC);
420}
Glauber de Oliveira Costa833d8462008-01-30 13:31:08 +0100421
Glauber de Oliveira Costad8954222008-01-30 13:31:08 +0100422#endif