Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6] / arch / x86 / kernel / paravirt.c
1 /*  Paravirtualization interfaces
2     Copyright (C) 2006 Rusty Russell IBM Corporation
3
4     This program is free software; you can redistribute it and/or modify
5     it under the terms of the GNU General Public License as published by
6     the Free Software Foundation; either version 2 of the License, or
7     (at your option) any later version.
8
9     This program is distributed in the hope that it will be useful,
10     but WITHOUT ANY WARRANTY; without even the implied warranty of
11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12     GNU General Public License for more details.
13
14     You should have received a copy of the GNU General Public License
15     along with this program; if not, write to the Free Software
16     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17
18     2007 - x86_64 support added by Glauber de Oliveira Costa, Red Hat Inc
19 */
20
21 #include <linux/errno.h>
22 #include <linux/module.h>
23 #include <linux/efi.h>
24 #include <linux/bcd.h>
25 #include <linux/highmem.h>
26
27 #include <asm/bug.h>
28 #include <asm/paravirt.h>
29 #include <asm/desc.h>
30 #include <asm/setup.h>
31 #include <asm/pgtable.h>
32 #include <asm/time.h>
33 #include <asm/pgalloc.h>
34 #include <asm/irq.h>
35 #include <asm/delay.h>
36 #include <asm/fixmap.h>
37 #include <asm/apic.h>
38 #include <asm/tlbflush.h>
39 #include <asm/timer.h>
40
41 /* nop stub */
42 void _paravirt_nop(void)
43 {
44 }
45
46 /* identity function, which can be inlined */
47 u32 _paravirt_ident_32(u32 x)
48 {
49         return x;
50 }
51
52 u64 _paravirt_ident_64(u64 x)
53 {
54         return x;
55 }
56
57 static void __init default_banner(void)
58 {
59         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
60                pv_info.name);
61 }
62
63 char *memory_setup(void)
64 {
65         return pv_init_ops.memory_setup();
66 }
67
68 /* Simple instruction patching code. */
69 #define DEF_NATIVE(ops, name, code)                                     \
70         extern const char start_##ops##_##name[], end_##ops##_##name[]; \
71         asm("start_" #ops "_" #name ": " code "; end_" #ops "_" #name ":")
72
73 /* Undefined instruction for dealing with missing ops pointers. */
74 static const unsigned char ud2a[] = { 0x0f, 0x0b };
75
76 unsigned paravirt_patch_nop(void)
77 {
78         return 0;
79 }
80
81 unsigned paravirt_patch_ignore(unsigned len)
82 {
83         return len;
84 }
85
86 struct branch {
87         unsigned char opcode;
88         u32 delta;
89 } __attribute__((packed));
90
91 unsigned paravirt_patch_call(void *insnbuf,
92                              const void *target, u16 tgt_clobbers,
93                              unsigned long addr, u16 site_clobbers,
94                              unsigned len)
95 {
96         struct branch *b = insnbuf;
97         unsigned long delta = (unsigned long)target - (addr+5);
98
99         if (tgt_clobbers & ~site_clobbers)
100                 return len;     /* target would clobber too much for this site */
101         if (len < 5)
102                 return len;     /* call too long for patch site */
103
104         b->opcode = 0xe8; /* call */
105         b->delta = delta;
106         BUILD_BUG_ON(sizeof(*b) != 5);
107
108         return 5;
109 }
110
111 unsigned paravirt_patch_jmp(void *insnbuf, const void *target,
112                             unsigned long addr, unsigned len)
113 {
114         struct branch *b = insnbuf;
115         unsigned long delta = (unsigned long)target - (addr+5);
116
117         if (len < 5)
118                 return len;     /* call too long for patch site */
119
120         b->opcode = 0xe9;       /* jmp */
121         b->delta = delta;
122
123         return 5;
124 }
125
126 /* Neat trick to map patch type back to the call within the
127  * corresponding structure. */
128 static void *get_call_destination(u8 type)
129 {
130         struct paravirt_patch_template tmpl = {
131                 .pv_init_ops = pv_init_ops,
132                 .pv_time_ops = pv_time_ops,
133                 .pv_cpu_ops = pv_cpu_ops,
134                 .pv_irq_ops = pv_irq_ops,
135                 .pv_apic_ops = pv_apic_ops,
136                 .pv_mmu_ops = pv_mmu_ops,
137                 .pv_lock_ops = pv_lock_ops,
138         };
139         return *((void **)&tmpl + type);
140 }
141
142 unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf,
143                                 unsigned long addr, unsigned len)
144 {
145         void *opfunc = get_call_destination(type);
146         unsigned ret;
147
148         if (opfunc == NULL)
149                 /* If there's no function, patch it with a ud2a (BUG) */
150                 ret = paravirt_patch_insns(insnbuf, len, ud2a, ud2a+sizeof(ud2a));
151         else if (opfunc == _paravirt_nop)
152                 /* If the operation is a nop, then nop the callsite */
153                 ret = paravirt_patch_nop();
154
155         /* identity functions just return their single argument */
156         else if (opfunc == _paravirt_ident_32)
157                 ret = paravirt_patch_ident_32(insnbuf, len);
158         else if (opfunc == _paravirt_ident_64)
159                 ret = paravirt_patch_ident_64(insnbuf, len);
160
161         else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) ||
162                  type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit) ||
163                  type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret32) ||
164                  type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64))
165                 /* If operation requires a jmp, then jmp */
166                 ret = paravirt_patch_jmp(insnbuf, opfunc, addr, len);
167         else
168                 /* Otherwise call the function; assume target could
169                    clobber any caller-save reg */
170                 ret = paravirt_patch_call(insnbuf, opfunc, CLBR_ANY,
171                                           addr, clobbers, len);
172
173         return ret;
174 }
175
176 unsigned paravirt_patch_insns(void *insnbuf, unsigned len,
177                               const char *start, const char *end)
178 {
179         unsigned insn_len = end - start;
180
181         if (insn_len > len || start == NULL)
182                 insn_len = len;
183         else
184                 memcpy(insnbuf, start, insn_len);
185
186         return insn_len;
187 }
188
189 void init_IRQ(void)
190 {
191         pv_irq_ops.init_IRQ();
192 }
193
194 static void native_flush_tlb(void)
195 {
196         __native_flush_tlb();
197 }
198
199 /*
200  * Global pages have to be flushed a bit differently. Not a real
201  * performance problem because this does not happen often.
202  */
203 static void native_flush_tlb_global(void)
204 {
205         __native_flush_tlb_global();
206 }
207
208 static void native_flush_tlb_single(unsigned long addr)
209 {
210         __native_flush_tlb_single(addr);
211 }
212
213 /* These are in entry.S */
214 extern void native_iret(void);
215 extern void native_irq_enable_sysexit(void);
216 extern void native_usergs_sysret32(void);
217 extern void native_usergs_sysret64(void);
218
219 static int __init print_banner(void)
220 {
221         pv_init_ops.banner();
222         return 0;
223 }
224 core_initcall(print_banner);
225
226 static struct resource reserve_ioports = {
227         .start = 0,
228         .end = IO_SPACE_LIMIT,
229         .name = "paravirt-ioport",
230         .flags = IORESOURCE_IO | IORESOURCE_BUSY,
231 };
232
233 /*
234  * Reserve the whole legacy IO space to prevent any legacy drivers
235  * from wasting time probing for their hardware.  This is a fairly
236  * brute-force approach to disabling all non-virtual drivers.
237  *
238  * Note that this must be called very early to have any effect.
239  */
240 int paravirt_disable_iospace(void)
241 {
242         return request_resource(&ioport_resource, &reserve_ioports);
243 }
244
245 static DEFINE_PER_CPU(enum paravirt_lazy_mode, paravirt_lazy_mode) = PARAVIRT_LAZY_NONE;
246
247 static inline void enter_lazy(enum paravirt_lazy_mode mode)
248 {
249         BUG_ON(__get_cpu_var(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE);
250         BUG_ON(preemptible());
251
252         __get_cpu_var(paravirt_lazy_mode) = mode;
253 }
254
255 void paravirt_leave_lazy(enum paravirt_lazy_mode mode)
256 {
257         BUG_ON(__get_cpu_var(paravirt_lazy_mode) != mode);
258         BUG_ON(preemptible());
259
260         __get_cpu_var(paravirt_lazy_mode) = PARAVIRT_LAZY_NONE;
261 }
262
263 void paravirt_enter_lazy_mmu(void)
264 {
265         enter_lazy(PARAVIRT_LAZY_MMU);
266 }
267
268 void paravirt_leave_lazy_mmu(void)
269 {
270         paravirt_leave_lazy(PARAVIRT_LAZY_MMU);
271 }
272
273 void paravirt_enter_lazy_cpu(void)
274 {
275         enter_lazy(PARAVIRT_LAZY_CPU);
276 }
277
278 void paravirt_leave_lazy_cpu(void)
279 {
280         paravirt_leave_lazy(PARAVIRT_LAZY_CPU);
281 }
282
283 enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
284 {
285         return __get_cpu_var(paravirt_lazy_mode);
286 }
287
288 void arch_flush_lazy_mmu_mode(void)
289 {
290         preempt_disable();
291
292         if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
293                 WARN_ON(preempt_count() == 1);
294                 arch_leave_lazy_mmu_mode();
295                 arch_enter_lazy_mmu_mode();
296         }
297
298         preempt_enable();
299 }
300
301 void arch_flush_lazy_cpu_mode(void)
302 {
303         preempt_disable();
304
305         if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
306                 WARN_ON(preempt_count() == 1);
307                 arch_leave_lazy_cpu_mode();
308                 arch_enter_lazy_cpu_mode();
309         }
310
311         preempt_enable();
312 }
313
314 struct pv_info pv_info = {
315         .name = "bare hardware",
316         .paravirt_enabled = 0,
317         .kernel_rpl = 0,
318         .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
319 };
320
321 struct pv_init_ops pv_init_ops = {
322         .patch = native_patch,
323         .banner = default_banner,
324         .arch_setup = paravirt_nop,
325         .memory_setup = machine_specific_memory_setup,
326 };
327
328 struct pv_time_ops pv_time_ops = {
329         .time_init = hpet_time_init,
330         .get_wallclock = native_get_wallclock,
331         .set_wallclock = native_set_wallclock,
332         .sched_clock = native_sched_clock,
333         .get_tsc_khz = native_calibrate_tsc,
334 };
335
336 struct pv_irq_ops pv_irq_ops = {
337         .init_IRQ = native_init_IRQ,
338         .save_fl = __PV_IS_CALLEE_SAVE(native_save_fl),
339         .restore_fl = __PV_IS_CALLEE_SAVE(native_restore_fl),
340         .irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable),
341         .irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable),
342         .safe_halt = native_safe_halt,
343         .halt = native_halt,
344 #ifdef CONFIG_X86_64
345         .adjust_exception_frame = paravirt_nop,
346 #endif
347 };
348
349 struct pv_cpu_ops pv_cpu_ops = {
350         .cpuid = native_cpuid,
351         .get_debugreg = native_get_debugreg,
352         .set_debugreg = native_set_debugreg,
353         .clts = native_clts,
354         .read_cr0 = native_read_cr0,
355         .write_cr0 = native_write_cr0,
356         .read_cr4 = native_read_cr4,
357         .read_cr4_safe = native_read_cr4_safe,
358         .write_cr4 = native_write_cr4,
359 #ifdef CONFIG_X86_64
360         .read_cr8 = native_read_cr8,
361         .write_cr8 = native_write_cr8,
362 #endif
363         .wbinvd = native_wbinvd,
364         .read_msr = native_read_msr_safe,
365         .read_msr_amd = native_read_msr_amd_safe,
366         .write_msr = native_write_msr_safe,
367         .read_tsc = native_read_tsc,
368         .read_pmc = native_read_pmc,
369         .read_tscp = native_read_tscp,
370         .load_tr_desc = native_load_tr_desc,
371         .set_ldt = native_set_ldt,
372         .load_gdt = native_load_gdt,
373         .load_idt = native_load_idt,
374         .store_gdt = native_store_gdt,
375         .store_idt = native_store_idt,
376         .store_tr = native_store_tr,
377         .load_tls = native_load_tls,
378 #ifdef CONFIG_X86_64
379         .load_gs_index = native_load_gs_index,
380 #endif
381         .write_ldt_entry = native_write_ldt_entry,
382         .write_gdt_entry = native_write_gdt_entry,
383         .write_idt_entry = native_write_idt_entry,
384
385         .alloc_ldt = paravirt_nop,
386         .free_ldt = paravirt_nop,
387
388         .load_sp0 = native_load_sp0,
389
390 #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
391         .irq_enable_sysexit = native_irq_enable_sysexit,
392 #endif
393 #ifdef CONFIG_X86_64
394 #ifdef CONFIG_IA32_EMULATION
395         .usergs_sysret32 = native_usergs_sysret32,
396 #endif
397         .usergs_sysret64 = native_usergs_sysret64,
398 #endif
399         .iret = native_iret,
400         .swapgs = native_swapgs,
401
402         .set_iopl_mask = native_set_iopl_mask,
403         .io_delay = native_io_delay,
404
405         .lazy_mode = {
406                 .enter = paravirt_nop,
407                 .leave = paravirt_nop,
408         },
409 };
410
411 struct pv_apic_ops pv_apic_ops = {
412 #ifdef CONFIG_X86_LOCAL_APIC
413         .setup_boot_clock = setup_boot_APIC_clock,
414         .setup_secondary_clock = setup_secondary_APIC_clock,
415         .startup_ipi_hook = paravirt_nop,
416 #endif
417 };
418
419 #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE)
420 /* 32-bit pagetable entries */
421 #define PTE_IDENT       __PV_IS_CALLEE_SAVE(_paravirt_ident_32)
422 #else
423 /* 64-bit pagetable entries */
424 #define PTE_IDENT       __PV_IS_CALLEE_SAVE(_paravirt_ident_64)
425 #endif
426
427 struct pv_mmu_ops pv_mmu_ops = {
428 #ifndef CONFIG_X86_64
429         .pagetable_setup_start = native_pagetable_setup_start,
430         .pagetable_setup_done = native_pagetable_setup_done,
431 #else
432         .pagetable_setup_start = paravirt_nop,
433         .pagetable_setup_done = paravirt_nop,
434 #endif
435
436         .read_cr2 = native_read_cr2,
437         .write_cr2 = native_write_cr2,
438         .read_cr3 = native_read_cr3,
439         .write_cr3 = native_write_cr3,
440
441         .flush_tlb_user = native_flush_tlb,
442         .flush_tlb_kernel = native_flush_tlb_global,
443         .flush_tlb_single = native_flush_tlb_single,
444         .flush_tlb_others = native_flush_tlb_others,
445
446         .pgd_alloc = __paravirt_pgd_alloc,
447         .pgd_free = paravirt_nop,
448
449         .alloc_pte = paravirt_nop,
450         .alloc_pmd = paravirt_nop,
451         .alloc_pmd_clone = paravirt_nop,
452         .alloc_pud = paravirt_nop,
453         .release_pte = paravirt_nop,
454         .release_pmd = paravirt_nop,
455         .release_pud = paravirt_nop,
456
457         .set_pte = native_set_pte,
458         .set_pte_at = native_set_pte_at,
459         .set_pmd = native_set_pmd,
460         .pte_update = paravirt_nop,
461         .pte_update_defer = paravirt_nop,
462
463         .ptep_modify_prot_start = __ptep_modify_prot_start,
464         .ptep_modify_prot_commit = __ptep_modify_prot_commit,
465
466 #ifdef CONFIG_HIGHPTE
467         .kmap_atomic_pte = kmap_atomic,
468 #endif
469
470 #if PAGETABLE_LEVELS >= 3
471 #ifdef CONFIG_X86_PAE
472         .set_pte_atomic = native_set_pte_atomic,
473         .pte_clear = native_pte_clear,
474         .pmd_clear = native_pmd_clear,
475 #endif
476         .set_pud = native_set_pud,
477
478         .pmd_val = PTE_IDENT,
479         .make_pmd = PTE_IDENT,
480
481 #if PAGETABLE_LEVELS == 4
482         .pud_val = PTE_IDENT,
483         .make_pud = PTE_IDENT,
484
485         .set_pgd = native_set_pgd,
486 #endif
487 #endif /* PAGETABLE_LEVELS >= 3 */
488
489         .pte_val = PTE_IDENT,
490         .pgd_val = PTE_IDENT,
491
492         .make_pte = PTE_IDENT,
493         .make_pgd = PTE_IDENT,
494
495         .dup_mmap = paravirt_nop,
496         .exit_mmap = paravirt_nop,
497         .activate_mm = paravirt_nop,
498
499         .lazy_mode = {
500                 .enter = paravirt_nop,
501                 .leave = paravirt_nop,
502         },
503
504         .set_fixmap = native_set_fixmap,
505 };
506
507 EXPORT_SYMBOL_GPL(pv_time_ops);
508 EXPORT_SYMBOL    (pv_cpu_ops);
509 EXPORT_SYMBOL    (pv_mmu_ops);
510 EXPORT_SYMBOL_GPL(pv_apic_ops);
511 EXPORT_SYMBOL_GPL(pv_info);
512 EXPORT_SYMBOL    (pv_irq_ops);