Merge commit 'origin/master' into for-linus/xen/master
[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/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(percpu_read(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE);
250
251         percpu_write(paravirt_lazy_mode, mode);
252 }
253
254 static void leave_lazy(enum paravirt_lazy_mode mode)
255 {
256         BUG_ON(percpu_read(paravirt_lazy_mode) != mode);
257
258         percpu_write(paravirt_lazy_mode, PARAVIRT_LAZY_NONE);
259 }
260
261 void paravirt_enter_lazy_mmu(void)
262 {
263         enter_lazy(PARAVIRT_LAZY_MMU);
264 }
265
266 void paravirt_leave_lazy_mmu(void)
267 {
268         leave_lazy(PARAVIRT_LAZY_MMU);
269 }
270
271 void paravirt_start_context_switch(struct task_struct *prev)
272 {
273         BUG_ON(preemptible());
274
275         if (percpu_read(paravirt_lazy_mode) == PARAVIRT_LAZY_MMU) {
276                 arch_leave_lazy_mmu_mode();
277                 set_ti_thread_flag(task_thread_info(prev), TIF_LAZY_MMU_UPDATES);
278         }
279         enter_lazy(PARAVIRT_LAZY_CPU);
280 }
281
282 void paravirt_end_context_switch(struct task_struct *next)
283 {
284         BUG_ON(preemptible());
285
286         leave_lazy(PARAVIRT_LAZY_CPU);
287
288         if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES))
289                 arch_enter_lazy_mmu_mode();
290 }
291
292 enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
293 {
294         if (in_interrupt())
295                 return PARAVIRT_LAZY_NONE;
296
297         return percpu_read(paravirt_lazy_mode);
298 }
299
300 void arch_flush_lazy_mmu_mode(void)
301 {
302         preempt_disable();
303
304         if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
305                 arch_leave_lazy_mmu_mode();
306                 arch_enter_lazy_mmu_mode();
307         }
308
309         preempt_enable();
310 }
311
312 struct pv_info pv_info = {
313         .name = "bare hardware",
314         .paravirt_enabled = 0,
315         .kernel_rpl = 0,
316         .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
317 };
318
319 struct pv_init_ops pv_init_ops = {
320         .patch = native_patch,
321         .banner = default_banner,
322         .arch_setup = paravirt_nop,
323         .memory_setup = machine_specific_memory_setup,
324 };
325
326 struct pv_time_ops pv_time_ops = {
327         .time_init = hpet_time_init,
328         .get_wallclock = native_get_wallclock,
329         .set_wallclock = native_set_wallclock,
330         .sched_clock = native_sched_clock,
331         .get_tsc_khz = native_calibrate_tsc,
332 };
333
334 struct pv_irq_ops pv_irq_ops = {
335         .init_IRQ = native_init_IRQ,
336         .save_fl = __PV_IS_CALLEE_SAVE(native_save_fl),
337         .restore_fl = __PV_IS_CALLEE_SAVE(native_restore_fl),
338         .irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable),
339         .irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable),
340         .safe_halt = native_safe_halt,
341         .halt = native_halt,
342 #ifdef CONFIG_X86_64
343         .adjust_exception_frame = paravirt_nop,
344 #endif
345 };
346
347 struct pv_cpu_ops pv_cpu_ops = {
348         .cpuid = native_cpuid,
349         .get_debugreg = native_get_debugreg,
350         .set_debugreg = native_set_debugreg,
351         .clts = native_clts,
352         .read_cr0 = native_read_cr0,
353         .write_cr0 = native_write_cr0,
354         .read_cr4 = native_read_cr4,
355         .read_cr4_safe = native_read_cr4_safe,
356         .write_cr4 = native_write_cr4,
357 #ifdef CONFIG_X86_64
358         .read_cr8 = native_read_cr8,
359         .write_cr8 = native_write_cr8,
360 #endif
361         .wbinvd = native_wbinvd,
362         .read_msr = native_read_msr_safe,
363         .read_msr_amd = native_read_msr_amd_safe,
364         .write_msr = native_write_msr_safe,
365         .read_tsc = native_read_tsc,
366         .read_pmc = native_read_pmc,
367         .read_tscp = native_read_tscp,
368         .load_tr_desc = native_load_tr_desc,
369         .set_ldt = native_set_ldt,
370         .load_gdt = native_load_gdt,
371         .load_idt = native_load_idt,
372         .store_gdt = native_store_gdt,
373         .store_idt = native_store_idt,
374         .store_tr = native_store_tr,
375         .load_tls = native_load_tls,
376 #ifdef CONFIG_X86_64
377         .load_gs_index = native_load_gs_index,
378 #endif
379         .write_ldt_entry = native_write_ldt_entry,
380         .write_gdt_entry = native_write_gdt_entry,
381         .write_idt_entry = native_write_idt_entry,
382
383         .alloc_ldt = paravirt_nop,
384         .free_ldt = paravirt_nop,
385
386         .load_sp0 = native_load_sp0,
387
388 #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
389         .irq_enable_sysexit = native_irq_enable_sysexit,
390 #endif
391 #ifdef CONFIG_X86_64
392 #ifdef CONFIG_IA32_EMULATION
393         .usergs_sysret32 = native_usergs_sysret32,
394 #endif
395         .usergs_sysret64 = native_usergs_sysret64,
396 #endif
397         .iret = native_iret,
398         .swapgs = native_swapgs,
399
400         .set_iopl_mask = native_set_iopl_mask,
401         .io_delay = native_io_delay,
402
403         .start_context_switch = paravirt_nop,
404         .end_context_switch = paravirt_nop,
405 };
406
407 struct pv_apic_ops pv_apic_ops = {
408 #ifdef CONFIG_X86_LOCAL_APIC
409         .setup_boot_clock = setup_boot_APIC_clock,
410         .setup_secondary_clock = setup_secondary_APIC_clock,
411         .startup_ipi_hook = paravirt_nop,
412 #endif
413 };
414
415 #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE)
416 /* 32-bit pagetable entries */
417 #define PTE_IDENT       __PV_IS_CALLEE_SAVE(_paravirt_ident_32)
418 #else
419 /* 64-bit pagetable entries */
420 #define PTE_IDENT       __PV_IS_CALLEE_SAVE(_paravirt_ident_64)
421 #endif
422
423 struct pv_mmu_ops pv_mmu_ops = {
424 #ifndef CONFIG_X86_64
425         .pagetable_setup_start = native_pagetable_setup_start,
426         .pagetable_setup_done = native_pagetable_setup_done,
427 #else
428         .pagetable_setup_start = paravirt_nop,
429         .pagetable_setup_done = paravirt_nop,
430 #endif
431
432         .read_cr2 = native_read_cr2,
433         .write_cr2 = native_write_cr2,
434         .read_cr3 = native_read_cr3,
435         .write_cr3 = native_write_cr3,
436
437         .flush_tlb_user = native_flush_tlb,
438         .flush_tlb_kernel = native_flush_tlb_global,
439         .flush_tlb_single = native_flush_tlb_single,
440         .flush_tlb_others = native_flush_tlb_others,
441
442         .pgd_alloc = __paravirt_pgd_alloc,
443         .pgd_free = paravirt_nop,
444
445         .alloc_pte = paravirt_nop,
446         .alloc_pmd = paravirt_nop,
447         .alloc_pmd_clone = paravirt_nop,
448         .alloc_pud = paravirt_nop,
449         .release_pte = paravirt_nop,
450         .release_pmd = paravirt_nop,
451         .release_pud = paravirt_nop,
452
453         .set_pte = native_set_pte,
454         .set_pte_at = native_set_pte_at,
455         .set_pmd = native_set_pmd,
456         .pte_update = paravirt_nop,
457         .pte_update_defer = paravirt_nop,
458
459         .ptep_modify_prot_start = __ptep_modify_prot_start,
460         .ptep_modify_prot_commit = __ptep_modify_prot_commit,
461
462 #ifdef CONFIG_HIGHPTE
463         .kmap_atomic_pte = kmap_atomic,
464 #endif
465
466 #if PAGETABLE_LEVELS >= 3
467 #ifdef CONFIG_X86_PAE
468         .set_pte_atomic = native_set_pte_atomic,
469         .pte_clear = native_pte_clear,
470         .pmd_clear = native_pmd_clear,
471 #endif
472         .set_pud = native_set_pud,
473
474         .pmd_val = PTE_IDENT,
475         .make_pmd = PTE_IDENT,
476
477 #if PAGETABLE_LEVELS == 4
478         .pud_val = PTE_IDENT,
479         .make_pud = PTE_IDENT,
480
481         .set_pgd = native_set_pgd,
482 #endif
483 #endif /* PAGETABLE_LEVELS >= 3 */
484
485         .pte_val = PTE_IDENT,
486         .pgd_val = PTE_IDENT,
487
488         .make_pte = PTE_IDENT,
489         .make_pgd = PTE_IDENT,
490
491         .dup_mmap = paravirt_nop,
492         .exit_mmap = paravirt_nop,
493         .activate_mm = paravirt_nop,
494
495         .lazy_mode = {
496                 .enter = paravirt_nop,
497                 .leave = paravirt_nop,
498         },
499
500         .set_fixmap = native_set_fixmap,
501 };
502
503 EXPORT_SYMBOL_GPL(pv_time_ops);
504 EXPORT_SYMBOL    (pv_cpu_ops);
505 EXPORT_SYMBOL    (pv_mmu_ops);
506 EXPORT_SYMBOL_GPL(pv_apic_ops);
507 EXPORT_SYMBOL_GPL(pv_info);
508 EXPORT_SYMBOL    (pv_irq_ops);