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