6dc4dca255e42e097455e2f6ec75bf0546682033
[linux-2.6.git] / 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/arch_hooks.h>
32 #include <asm/pgtable.h>
33 #include <asm/time.h>
34 #include <asm/pgalloc.h>
35 #include <asm/irq.h>
36 #include <asm/delay.h>
37 #include <asm/fixmap.h>
38 #include <asm/apic.h>
39 #include <asm/tlbflush.h>
40 #include <asm/timer.h>
41
42 /* nop stub */
43 void _paravirt_nop(void)
44 {
45 }
46
47 /* identity function, which can be inlined */
48 u32 _paravirt_ident_32(u32 x)
49 {
50         return x;
51 }
52
53 u64 _paravirt_ident_64(u64 x)
54 {
55         return x;
56 }
57
58 static void __init default_banner(void)
59 {
60         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
61                pv_info.name);
62 }
63
64 char *memory_setup(void)
65 {
66         return pv_init_ops.memory_setup();
67 }
68
69 /* Simple instruction patching code. */
70 #define DEF_NATIVE(ops, name, code)                                     \
71         extern const char start_##ops##_##name[], end_##ops##_##name[]; \
72         asm("start_" #ops "_" #name ": " code "; end_" #ops "_" #name ":")
73
74 /* Undefined instruction for dealing with missing ops pointers. */
75 static const unsigned char ud2a[] = { 0x0f, 0x0b };
76
77 unsigned paravirt_patch_nop(void)
78 {
79         return 0;
80 }
81
82 unsigned paravirt_patch_ignore(unsigned len)
83 {
84         return len;
85 }
86
87 struct branch {
88         unsigned char opcode;
89         u32 delta;
90 } __attribute__((packed));
91
92 unsigned paravirt_patch_call(void *insnbuf,
93                              const void *target, u16 tgt_clobbers,
94                              unsigned long addr, u16 site_clobbers,
95                              unsigned len)
96 {
97         struct branch *b = insnbuf;
98         unsigned long delta = (unsigned long)target - (addr+5);
99
100         if (tgt_clobbers & ~site_clobbers)
101                 return len;     /* target would clobber too much for this site */
102         if (len < 5)
103                 return len;     /* call too long for patch site */
104
105         b->opcode = 0xe8; /* call */
106         b->delta = delta;
107         BUILD_BUG_ON(sizeof(*b) != 5);
108
109         return 5;
110 }
111
112 unsigned paravirt_patch_jmp(void *insnbuf, const void *target,
113                             unsigned long addr, unsigned len)
114 {
115         struct branch *b = insnbuf;
116         unsigned long delta = (unsigned long)target - (addr+5);
117
118         if (len < 5)
119                 return len;     /* call too long for patch site */
120
121         b->opcode = 0xe9;       /* jmp */
122         b->delta = delta;
123
124         return 5;
125 }
126
127 /* Neat trick to map patch type back to the call within the
128  * corresponding structure. */
129 static void *get_call_destination(u8 type)
130 {
131         struct paravirt_patch_template tmpl = {
132                 .pv_init_ops = pv_init_ops,
133                 .pv_time_ops = pv_time_ops,
134                 .pv_cpu_ops = pv_cpu_ops,
135                 .pv_irq_ops = pv_irq_ops,
136                 .pv_apic_ops = pv_apic_ops,
137                 .pv_mmu_ops = pv_mmu_ops,
138                 .pv_lock_ops = pv_lock_ops,
139         };
140         return *((void **)&tmpl + type);
141 }
142
143 unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf,
144                                 unsigned long addr, unsigned len)
145 {
146         void *opfunc = get_call_destination(type);
147         unsigned ret;
148
149         if (opfunc == NULL)
150                 /* If there's no function, patch it with a ud2a (BUG) */
151                 ret = paravirt_patch_insns(insnbuf, len, ud2a, ud2a+sizeof(ud2a));
152         else if (opfunc == _paravirt_nop)
153                 /* If the operation is a nop, then nop the callsite */
154                 ret = paravirt_patch_nop();
155
156         /* identity functions just return their single argument */
157         else if (opfunc == _paravirt_ident_32)
158                 ret = paravirt_patch_ident_32(insnbuf, len);
159         else if (opfunc == _paravirt_ident_64)
160                 ret = paravirt_patch_ident_64(insnbuf, len);
161
162         else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) ||
163                  type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit) ||
164                  type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret32) ||
165                  type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64))
166                 /* If operation requires a jmp, then jmp */
167                 ret = paravirt_patch_jmp(insnbuf, opfunc, addr, len);
168         else
169                 /* Otherwise call the function; assume target could
170                    clobber any caller-save reg */
171                 ret = paravirt_patch_call(insnbuf, opfunc, CLBR_ANY,
172                                           addr, clobbers, len);
173
174         return ret;
175 }
176
177 unsigned paravirt_patch_insns(void *insnbuf, unsigned len,
178                               const char *start, const char *end)
179 {
180         unsigned insn_len = end - start;
181
182         if (insn_len > len || start == NULL)
183                 insn_len = len;
184         else
185                 memcpy(insnbuf, start, insn_len);
186
187         return insn_len;
188 }
189
190 void init_IRQ(void)
191 {
192         pv_irq_ops.init_IRQ();
193 }
194
195 static void native_flush_tlb(void)
196 {
197         __native_flush_tlb();
198 }
199
200 /*
201  * Global pages have to be flushed a bit differently. Not a real
202  * performance problem because this does not happen often.
203  */
204 static void native_flush_tlb_global(void)
205 {
206         __native_flush_tlb_global();
207 }
208
209 static void native_flush_tlb_single(unsigned long addr)
210 {
211         __native_flush_tlb_single(addr);
212 }
213
214 /* These are in entry.S */
215 extern void native_iret(void);
216 extern void native_irq_enable_sysexit(void);
217 extern void native_usergs_sysret32(void);
218 extern void native_usergs_sysret64(void);
219
220 static int __init print_banner(void)
221 {
222         pv_init_ops.banner();
223         return 0;
224 }
225 core_initcall(print_banner);
226
227 static struct resource reserve_ioports = {
228         .start = 0,
229         .end = IO_SPACE_LIMIT,
230         .name = "paravirt-ioport",
231         .flags = IORESOURCE_IO | IORESOURCE_BUSY,
232 };
233
234 /*
235  * Reserve the whole legacy IO space to prevent any legacy drivers
236  * from wasting time probing for their hardware.  This is a fairly
237  * brute-force approach to disabling all non-virtual drivers.
238  *
239  * Note that this must be called very early to have any effect.
240  */
241 int paravirt_disable_iospace(void)
242 {
243         return request_resource(&ioport_resource, &reserve_ioports);
244 }
245
246 static DEFINE_PER_CPU(enum paravirt_lazy_mode, paravirt_lazy_mode) = PARAVIRT_LAZY_NONE;
247
248 static inline void enter_lazy(enum paravirt_lazy_mode mode)
249 {
250         BUG_ON(__get_cpu_var(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE);
251         BUG_ON(preemptible());
252
253         __get_cpu_var(paravirt_lazy_mode) = mode;
254 }
255
256 void paravirt_leave_lazy(enum paravirt_lazy_mode mode)
257 {
258         BUG_ON(__get_cpu_var(paravirt_lazy_mode) != mode);
259         BUG_ON(preemptible());
260
261         __get_cpu_var(paravirt_lazy_mode) = PARAVIRT_LAZY_NONE;
262 }
263
264 void paravirt_enter_lazy_mmu(void)
265 {
266         enter_lazy(PARAVIRT_LAZY_MMU);
267 }
268
269 void paravirt_leave_lazy_mmu(void)
270 {
271         paravirt_leave_lazy(PARAVIRT_LAZY_MMU);
272 }
273
274 void paravirt_enter_lazy_cpu(void)
275 {
276         enter_lazy(PARAVIRT_LAZY_CPU);
277 }
278
279 void paravirt_leave_lazy_cpu(void)
280 {
281         paravirt_leave_lazy(PARAVIRT_LAZY_CPU);
282 }
283
284 enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
285 {
286         return __get_cpu_var(paravirt_lazy_mode);
287 }
288
289 void arch_flush_lazy_mmu_mode(void)
290 {
291         preempt_disable();
292
293         if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
294                 WARN_ON(preempt_count() == 1);
295                 arch_leave_lazy_mmu_mode();
296                 arch_enter_lazy_mmu_mode();
297         }
298
299         preempt_enable();
300 }
301
302 void arch_flush_lazy_cpu_mode(void)
303 {
304         preempt_disable();
305
306         if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
307                 WARN_ON(preempt_count() == 1);
308                 arch_leave_lazy_cpu_mode();
309                 arch_enter_lazy_cpu_mode();
310         }
311
312         preempt_enable();
313 }
314
315 struct pv_info pv_info = {
316         .name = "bare hardware",
317         .paravirt_enabled = 0,
318         .kernel_rpl = 0,
319         .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
320 };
321
322 struct pv_init_ops pv_init_ops = {
323         .patch = native_patch,
324         .banner = default_banner,
325         .arch_setup = paravirt_nop,
326         .memory_setup = machine_specific_memory_setup,
327 };
328
329 struct pv_time_ops pv_time_ops = {
330         .time_init = hpet_time_init,
331         .get_wallclock = native_get_wallclock,
332         .set_wallclock = native_set_wallclock,
333         .sched_clock = native_sched_clock,
334         .get_tsc_khz = native_calibrate_tsc,
335 };
336
337 struct pv_irq_ops pv_irq_ops = {
338         .init_IRQ = native_init_IRQ,
339         .save_fl = __PV_IS_CALLEE_SAVE(native_save_fl),
340         .restore_fl = __PV_IS_CALLEE_SAVE(native_restore_fl),
341         .irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable),
342         .irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable),
343         .safe_halt = native_safe_halt,
344         .halt = native_halt,
345 #ifdef CONFIG_X86_64
346         .adjust_exception_frame = paravirt_nop,
347 #endif
348 };
349
350 struct pv_cpu_ops pv_cpu_ops = {
351         .cpuid = native_cpuid,
352         .get_debugreg = native_get_debugreg,
353         .set_debugreg = native_set_debugreg,
354         .clts = native_clts,
355         .read_cr0 = native_read_cr0,
356         .write_cr0 = native_write_cr0,
357         .read_cr4 = native_read_cr4,
358         .read_cr4_safe = native_read_cr4_safe,
359         .write_cr4 = native_write_cr4,
360 #ifdef CONFIG_X86_64
361         .read_cr8 = native_read_cr8,
362         .write_cr8 = native_write_cr8,
363 #endif
364         .wbinvd = native_wbinvd,
365         .read_msr = native_read_msr_safe,
366         .read_msr_amd = native_read_msr_amd_safe,
367         .write_msr = native_write_msr_safe,
368         .read_tsc = native_read_tsc,
369         .read_pmc = native_read_pmc,
370         .read_tscp = native_read_tscp,
371         .load_tr_desc = native_load_tr_desc,
372         .set_ldt = native_set_ldt,
373         .load_gdt = native_load_gdt,
374         .load_idt = native_load_idt,
375         .store_gdt = native_store_gdt,
376         .store_idt = native_store_idt,
377         .store_tr = native_store_tr,
378         .load_tls = native_load_tls,
379 #ifdef CONFIG_X86_64
380         .load_gs_index = native_load_gs_index,
381 #endif
382         .write_ldt_entry = native_write_ldt_entry,
383         .write_gdt_entry = native_write_gdt_entry,
384         .write_idt_entry = native_write_idt_entry,
385
386         .alloc_ldt = paravirt_nop,
387         .free_ldt = paravirt_nop,
388
389         .load_sp0 = native_load_sp0,
390
391 #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
392         .irq_enable_sysexit = native_irq_enable_sysexit,
393 #endif
394 #ifdef CONFIG_X86_64
395 #ifdef CONFIG_IA32_EMULATION
396         .usergs_sysret32 = native_usergs_sysret32,
397 #endif
398         .usergs_sysret64 = native_usergs_sysret64,
399 #endif
400         .iret = native_iret,
401         .swapgs = native_swapgs,
402
403         .set_iopl_mask = native_set_iopl_mask,
404         .io_delay = native_io_delay,
405
406         .lazy_mode = {
407                 .enter = paravirt_nop,
408                 .leave = paravirt_nop,
409         },
410 };
411
412 struct pv_apic_ops pv_apic_ops = {
413 #ifdef CONFIG_X86_LOCAL_APIC
414         .setup_boot_clock = setup_boot_APIC_clock,
415         .setup_secondary_clock = setup_secondary_APIC_clock,
416         .startup_ipi_hook = paravirt_nop,
417 #endif
418 };
419
420 #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE)
421 /* 32-bit pagetable entries */
422 #define PTE_IDENT       __PV_IS_CALLEE_SAVE(_paravirt_ident_32)
423 #else
424 /* 64-bit pagetable entries */
425 #define PTE_IDENT       __PV_IS_CALLEE_SAVE(_paravirt_ident_64)
426 #endif
427
428 struct pv_mmu_ops pv_mmu_ops = {
429 #ifndef CONFIG_X86_64
430         .pagetable_setup_start = native_pagetable_setup_start,
431         .pagetable_setup_done = native_pagetable_setup_done,
432 #else
433         .pagetable_setup_start = paravirt_nop,
434         .pagetable_setup_done = paravirt_nop,
435 #endif
436
437         .read_cr2 = native_read_cr2,
438         .write_cr2 = native_write_cr2,
439         .read_cr3 = native_read_cr3,
440         .write_cr3 = native_write_cr3,
441
442         .flush_tlb_user = native_flush_tlb,
443         .flush_tlb_kernel = native_flush_tlb_global,
444         .flush_tlb_single = native_flush_tlb_single,
445         .flush_tlb_others = native_flush_tlb_others,
446
447         .pgd_alloc = __paravirt_pgd_alloc,
448         .pgd_free = paravirt_nop,
449
450         .alloc_pte = paravirt_nop,
451         .alloc_pmd = paravirt_nop,
452         .alloc_pmd_clone = paravirt_nop,
453         .alloc_pud = paravirt_nop,
454         .release_pte = paravirt_nop,
455         .release_pmd = paravirt_nop,
456         .release_pud = paravirt_nop,
457
458         .set_pte = native_set_pte,
459         .set_pte_at = native_set_pte_at,
460         .set_pmd = native_set_pmd,
461         .pte_update = paravirt_nop,
462         .pte_update_defer = paravirt_nop,
463
464         .ptep_modify_prot_start = __ptep_modify_prot_start,
465         .ptep_modify_prot_commit = __ptep_modify_prot_commit,
466
467 #ifdef CONFIG_HIGHPTE
468         .kmap_atomic_pte = kmap_atomic,
469 #endif
470
471 #if PAGETABLE_LEVELS >= 3
472 #ifdef CONFIG_X86_PAE
473         .set_pte_atomic = native_set_pte_atomic,
474         .set_pte_present = native_set_pte_present,
475         .pte_clear = native_pte_clear,
476         .pmd_clear = native_pmd_clear,
477 #endif
478         .set_pud = native_set_pud,
479
480         .pmd_val = PTE_IDENT,
481         .make_pmd = PTE_IDENT,
482
483 #if PAGETABLE_LEVELS == 4
484         .pud_val = PTE_IDENT,
485         .make_pud = PTE_IDENT,
486
487         .set_pgd = native_set_pgd,
488 #endif
489 #endif /* PAGETABLE_LEVELS >= 3 */
490
491         .pte_val = PTE_IDENT,
492         .pgd_val = PTE_IDENT,
493
494         .make_pte = PTE_IDENT,
495         .make_pgd = PTE_IDENT,
496
497         .dup_mmap = paravirt_nop,
498         .exit_mmap = paravirt_nop,
499         .activate_mm = paravirt_nop,
500
501         .lazy_mode = {
502                 .enter = paravirt_nop,
503                 .leave = paravirt_nop,
504         },
505
506         .set_fixmap = native_set_fixmap,
507 };
508
509 EXPORT_SYMBOL_GPL(pv_time_ops);
510 EXPORT_SYMBOL    (pv_cpu_ops);
511 EXPORT_SYMBOL    (pv_mmu_ops);
512 EXPORT_SYMBOL_GPL(pv_apic_ops);
513 EXPORT_SYMBOL_GPL(pv_info);
514 EXPORT_SYMBOL    (pv_irq_ops);