74f0c5ea2a0388af848faa058804cd9df86f4391
[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/time.h>
33 #include <asm/irq.h>
34 #include <asm/delay.h>
35 #include <asm/fixmap.h>
36 #include <asm/apic.h>
37 #include <asm/tlbflush.h>
38 #include <asm/timer.h>
39
40 /* nop stub */
41 void _paravirt_nop(void)
42 {
43 }
44
45 static void __init default_banner(void)
46 {
47         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
48                pv_info.name);
49 }
50
51 char *memory_setup(void)
52 {
53         return pv_init_ops.memory_setup();
54 }
55
56 /* Simple instruction patching code. */
57 #define DEF_NATIVE(ops, name, code)                                     \
58         extern const char start_##ops##_##name[], end_##ops##_##name[]; \
59         asm("start_" #ops "_" #name ": " code "; end_" #ops "_" #name ":")
60
61 /* Undefined instruction for dealing with missing ops pointers. */
62 static const unsigned char ud2a[] = { 0x0f, 0x0b };
63
64 unsigned paravirt_patch_nop(void)
65 {
66         return 0;
67 }
68
69 unsigned paravirt_patch_ignore(unsigned len)
70 {
71         return len;
72 }
73
74 struct branch {
75         unsigned char opcode;
76         u32 delta;
77 } __attribute__((packed));
78
79 unsigned paravirt_patch_call(void *insnbuf,
80                              const void *target, u16 tgt_clobbers,
81                              unsigned long addr, u16 site_clobbers,
82                              unsigned len)
83 {
84         struct branch *b = insnbuf;
85         unsigned long delta = (unsigned long)target - (addr+5);
86
87         if (tgt_clobbers & ~site_clobbers)
88                 return len;     /* target would clobber too much for this site */
89         if (len < 5)
90                 return len;     /* call too long for patch site */
91
92         b->opcode = 0xe8; /* call */
93         b->delta = delta;
94         BUILD_BUG_ON(sizeof(*b) != 5);
95
96         return 5;
97 }
98
99 unsigned paravirt_patch_jmp(void *insnbuf, const void *target,
100                             unsigned long addr, unsigned len)
101 {
102         struct branch *b = insnbuf;
103         unsigned long delta = (unsigned long)target - (addr+5);
104
105         if (len < 5)
106                 return len;     /* call too long for patch site */
107
108         b->opcode = 0xe9;       /* jmp */
109         b->delta = delta;
110
111         return 5;
112 }
113
114 /* Neat trick to map patch type back to the call within the
115  * corresponding structure. */
116 static void *get_call_destination(u8 type)
117 {
118         struct paravirt_patch_template tmpl = {
119                 .pv_init_ops = pv_init_ops,
120                 .pv_time_ops = pv_time_ops,
121                 .pv_cpu_ops = pv_cpu_ops,
122                 .pv_irq_ops = pv_irq_ops,
123                 .pv_apic_ops = pv_apic_ops,
124                 .pv_mmu_ops = pv_mmu_ops,
125         };
126         return *((void **)&tmpl + type);
127 }
128
129 unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf,
130                                 unsigned long addr, unsigned len)
131 {
132         void *opfunc = get_call_destination(type);
133         unsigned ret;
134
135         if (opfunc == NULL)
136                 /* If there's no function, patch it with a ud2a (BUG) */
137                 ret = paravirt_patch_insns(insnbuf, len, ud2a, ud2a+sizeof(ud2a));
138         else if (opfunc == paravirt_nop)
139                 /* If the operation is a nop, then nop the callsite */
140                 ret = paravirt_patch_nop();
141         else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) ||
142                  type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_syscall_ret))
143                 /* If operation requires a jmp, then jmp */
144                 ret = paravirt_patch_jmp(insnbuf, opfunc, addr, len);
145         else
146                 /* Otherwise call the function; assume target could
147                    clobber any caller-save reg */
148                 ret = paravirt_patch_call(insnbuf, opfunc, CLBR_ANY,
149                                           addr, clobbers, len);
150
151         return ret;
152 }
153
154 unsigned paravirt_patch_insns(void *insnbuf, unsigned len,
155                               const char *start, const char *end)
156 {
157         unsigned insn_len = end - start;
158
159         if (insn_len > len || start == NULL)
160                 insn_len = len;
161         else
162                 memcpy(insnbuf, start, insn_len);
163
164         return insn_len;
165 }
166
167 void init_IRQ(void)
168 {
169         pv_irq_ops.init_IRQ();
170 }
171
172 static void native_flush_tlb(void)
173 {
174         __native_flush_tlb();
175 }
176
177 /*
178  * Global pages have to be flushed a bit differently. Not a real
179  * performance problem because this does not happen often.
180  */
181 static void native_flush_tlb_global(void)
182 {
183         __native_flush_tlb_global();
184 }
185
186 static void native_flush_tlb_single(unsigned long addr)
187 {
188         __native_flush_tlb_single(addr);
189 }
190
191 /* These are in entry.S */
192 extern void native_iret(void);
193 extern void native_irq_enable_syscall_ret(void);
194
195 static int __init print_banner(void)
196 {
197         pv_init_ops.banner();
198         return 0;
199 }
200 core_initcall(print_banner);
201
202 static struct resource reserve_ioports = {
203         .start = 0,
204         .end = IO_SPACE_LIMIT,
205         .name = "paravirt-ioport",
206         .flags = IORESOURCE_IO | IORESOURCE_BUSY,
207 };
208
209 /*
210  * Reserve the whole legacy IO space to prevent any legacy drivers
211  * from wasting time probing for their hardware.  This is a fairly
212  * brute-force approach to disabling all non-virtual drivers.
213  *
214  * Note that this must be called very early to have any effect.
215  */
216 int paravirt_disable_iospace(void)
217 {
218         return request_resource(&ioport_resource, &reserve_ioports);
219 }
220
221 static DEFINE_PER_CPU(enum paravirt_lazy_mode, paravirt_lazy_mode) = PARAVIRT_LAZY_NONE;
222
223 static inline void enter_lazy(enum paravirt_lazy_mode mode)
224 {
225         BUG_ON(__get_cpu_var(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE);
226         BUG_ON(preemptible());
227
228         __get_cpu_var(paravirt_lazy_mode) = mode;
229 }
230
231 void paravirt_leave_lazy(enum paravirt_lazy_mode mode)
232 {
233         BUG_ON(__get_cpu_var(paravirt_lazy_mode) != mode);
234         BUG_ON(preemptible());
235
236         __get_cpu_var(paravirt_lazy_mode) = PARAVIRT_LAZY_NONE;
237 }
238
239 void paravirt_enter_lazy_mmu(void)
240 {
241         enter_lazy(PARAVIRT_LAZY_MMU);
242 }
243
244 void paravirt_leave_lazy_mmu(void)
245 {
246         paravirt_leave_lazy(PARAVIRT_LAZY_MMU);
247 }
248
249 void paravirt_enter_lazy_cpu(void)
250 {
251         enter_lazy(PARAVIRT_LAZY_CPU);
252 }
253
254 void paravirt_leave_lazy_cpu(void)
255 {
256         paravirt_leave_lazy(PARAVIRT_LAZY_CPU);
257 }
258
259 enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
260 {
261         return __get_cpu_var(paravirt_lazy_mode);
262 }
263
264 struct pv_info pv_info = {
265         .name = "bare hardware",
266         .paravirt_enabled = 0,
267         .kernel_rpl = 0,
268         .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
269 };
270
271 struct pv_init_ops pv_init_ops = {
272         .patch = native_patch,
273         .banner = default_banner,
274         .arch_setup = paravirt_nop,
275         .memory_setup = machine_specific_memory_setup,
276 };
277
278 struct pv_time_ops pv_time_ops = {
279         .time_init = hpet_time_init,
280         .get_wallclock = native_get_wallclock,
281         .set_wallclock = native_set_wallclock,
282         .sched_clock = native_sched_clock,
283         .get_cpu_khz = native_calculate_cpu_khz,
284 };
285
286 struct pv_irq_ops pv_irq_ops = {
287         .init_IRQ = native_init_IRQ,
288         .save_fl = native_save_fl,
289         .restore_fl = native_restore_fl,
290         .irq_disable = native_irq_disable,
291         .irq_enable = native_irq_enable,
292         .safe_halt = native_safe_halt,
293         .halt = native_halt,
294 };
295
296 struct pv_cpu_ops pv_cpu_ops = {
297         .cpuid = native_cpuid,
298         .get_debugreg = native_get_debugreg,
299         .set_debugreg = native_set_debugreg,
300         .clts = native_clts,
301         .read_cr0 = native_read_cr0,
302         .write_cr0 = native_write_cr0,
303         .read_cr4 = native_read_cr4,
304         .read_cr4_safe = native_read_cr4_safe,
305         .write_cr4 = native_write_cr4,
306 #ifdef CONFIG_X86_64
307         .read_cr8 = native_read_cr8,
308         .write_cr8 = native_write_cr8,
309 #endif
310         .wbinvd = native_wbinvd,
311         .read_msr = native_read_msr_safe,
312         .write_msr = native_write_msr_safe,
313         .read_tsc = native_read_tsc,
314         .read_pmc = native_read_pmc,
315         .read_tscp = native_read_tscp,
316         .load_tr_desc = native_load_tr_desc,
317         .set_ldt = native_set_ldt,
318         .load_gdt = native_load_gdt,
319         .load_idt = native_load_idt,
320         .store_gdt = native_store_gdt,
321         .store_idt = native_store_idt,
322         .store_tr = native_store_tr,
323         .load_tls = native_load_tls,
324         .write_ldt_entry = native_write_ldt_entry,
325         .write_gdt_entry = native_write_gdt_entry,
326         .write_idt_entry = native_write_idt_entry,
327         .load_sp0 = native_load_sp0,
328
329         .irq_enable_syscall_ret = native_irq_enable_syscall_ret,
330         .iret = native_iret,
331         .swapgs = native_swapgs,
332
333         .set_iopl_mask = native_set_iopl_mask,
334         .io_delay = native_io_delay,
335
336         .lazy_mode = {
337                 .enter = paravirt_nop,
338                 .leave = paravirt_nop,
339         },
340 };
341
342 struct pv_apic_ops pv_apic_ops = {
343 #ifdef CONFIG_X86_LOCAL_APIC
344         .apic_write = native_apic_write,
345         .apic_write_atomic = native_apic_write_atomic,
346         .apic_read = native_apic_read,
347         .setup_boot_clock = setup_boot_APIC_clock,
348         .setup_secondary_clock = setup_secondary_APIC_clock,
349         .startup_ipi_hook = paravirt_nop,
350 #endif
351 };
352
353 struct pv_mmu_ops pv_mmu_ops = {
354 #ifndef CONFIG_X86_64
355         .pagetable_setup_start = native_pagetable_setup_start,
356         .pagetable_setup_done = native_pagetable_setup_done,
357 #endif
358
359         .read_cr2 = native_read_cr2,
360         .write_cr2 = native_write_cr2,
361         .read_cr3 = native_read_cr3,
362         .write_cr3 = native_write_cr3,
363
364         .flush_tlb_user = native_flush_tlb,
365         .flush_tlb_kernel = native_flush_tlb_global,
366         .flush_tlb_single = native_flush_tlb_single,
367         .flush_tlb_others = native_flush_tlb_others,
368
369         .alloc_pte = paravirt_nop,
370         .alloc_pmd = paravirt_nop,
371         .alloc_pmd_clone = paravirt_nop,
372         .alloc_pud = paravirt_nop,
373         .release_pte = paravirt_nop,
374         .release_pmd = paravirt_nop,
375         .release_pud = paravirt_nop,
376
377         .set_pte = native_set_pte,
378         .set_pte_at = native_set_pte_at,
379         .set_pmd = native_set_pmd,
380         .pte_update = paravirt_nop,
381         .pte_update_defer = paravirt_nop,
382
383 #ifdef CONFIG_HIGHPTE
384         .kmap_atomic_pte = kmap_atomic,
385 #endif
386
387 #if PAGETABLE_LEVELS >= 3
388 #ifdef CONFIG_X86_PAE
389         .set_pte_atomic = native_set_pte_atomic,
390         .set_pte_present = native_set_pte_present,
391         .pte_clear = native_pte_clear,
392         .pmd_clear = native_pmd_clear,
393 #endif
394         .set_pud = native_set_pud,
395         .pmd_val = native_pmd_val,
396         .make_pmd = native_make_pmd,
397
398 #if PAGETABLE_LEVELS == 4
399         .pud_val = native_pud_val,
400         .make_pud = native_make_pud,
401         .set_pgd = native_set_pgd,
402 #endif
403 #endif /* PAGETABLE_LEVELS >= 3 */
404
405         .pte_val = native_pte_val,
406         .pgd_val = native_pgd_val,
407
408         .make_pte = native_make_pte,
409         .make_pgd = native_make_pgd,
410
411         .dup_mmap = paravirt_nop,
412         .exit_mmap = paravirt_nop,
413         .activate_mm = paravirt_nop,
414
415         .lazy_mode = {
416                 .enter = paravirt_nop,
417                 .leave = paravirt_nop,
418         },
419 };
420
421 EXPORT_SYMBOL_GPL(pv_time_ops);
422 EXPORT_SYMBOL    (pv_cpu_ops);
423 EXPORT_SYMBOL    (pv_mmu_ops);
424 EXPORT_SYMBOL_GPL(pv_apic_ops);
425 EXPORT_SYMBOL_GPL(pv_info);
426 EXPORT_SYMBOL    (pv_irq_ops);