[PATCH] i386: PARAVIRT: revert map_pt_hook.
[linux-block.git] / arch / i386 / kernel / paravirt.c
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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#include <linux/errno.h>
19#include <linux/module.h>
20#include <linux/efi.h>
21#include <linux/bcd.h>
c9ccf30d 22#include <linux/start_kernel.h>
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23
24#include <asm/bug.h>
25#include <asm/paravirt.h>
26#include <asm/desc.h>
27#include <asm/setup.h>
28#include <asm/arch_hooks.h>
29#include <asm/time.h>
30#include <asm/irq.h>
31#include <asm/delay.h>
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32#include <asm/fixmap.h>
33#include <asm/apic.h>
da181a8b 34#include <asm/tlbflush.h>
6cb9a835 35#include <asm/timer.h>
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36
37/* nop stub */
45876233 38void _paravirt_nop(void)
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39{
40}
41
42static void __init default_banner(void)
43{
44 printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
45 paravirt_ops.name);
46}
47
48char *memory_setup(void)
49{
50 return paravirt_ops.memory_setup();
51}
52
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53/* Simple instruction patching code. */
54#define DEF_NATIVE(name, code) \
55 extern const char start_##name[], end_##name[]; \
56 asm("start_" #name ": " code "; end_" #name ":")
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JF
57
58DEF_NATIVE(irq_disable, "cli");
59DEF_NATIVE(irq_enable, "sti");
60DEF_NATIVE(restore_fl, "push %eax; popf");
61DEF_NATIVE(save_fl, "pushf; pop %eax");
139ec7c4 62DEF_NATIVE(iret, "iret");
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JF
63DEF_NATIVE(irq_enable_sysexit, "sti; sysexit");
64DEF_NATIVE(read_cr2, "mov %cr2, %eax");
65DEF_NATIVE(write_cr3, "mov %eax, %cr3");
66DEF_NATIVE(read_cr3, "mov %cr3, %eax");
67DEF_NATIVE(clts, "clts");
68DEF_NATIVE(read_tsc, "rdtsc");
139ec7c4 69
63f70270 70DEF_NATIVE(ud2a, "ud2a");
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71
72static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len)
73{
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74 const unsigned char *start, *end;
75 unsigned ret;
76
77 switch(type) {
78#define SITE(x) case PARAVIRT_PATCH(x): start = start_##x; end = end_##x; goto patch_site
79 SITE(irq_disable);
80 SITE(irq_enable);
81 SITE(restore_fl);
82 SITE(save_fl);
83 SITE(iret);
84 SITE(irq_enable_sysexit);
85 SITE(read_cr2);
86 SITE(read_cr3);
87 SITE(write_cr3);
88 SITE(clts);
89 SITE(read_tsc);
90#undef SITE
91
92 patch_site:
93 ret = paravirt_patch_insns(insns, len, start, end);
94 break;
95
96 case PARAVIRT_PATCH(make_pgd):
97 case PARAVIRT_PATCH(make_pte):
98 case PARAVIRT_PATCH(pgd_val):
99 case PARAVIRT_PATCH(pte_val):
100#ifdef CONFIG_X86_PAE
101 case PARAVIRT_PATCH(make_pmd):
102 case PARAVIRT_PATCH(pmd_val):
103#endif
104 /* These functions end up returning exactly what
105 they're passed, in the same registers. */
106 ret = paravirt_patch_nop();
107 break;
108
109 default:
110 ret = paravirt_patch_default(type, clobbers, insns, len);
111 break;
112 }
113
114 return ret;
115}
116
117unsigned paravirt_patch_nop(void)
118{
119 return 0;
120}
121
122unsigned paravirt_patch_ignore(unsigned len)
123{
124 return len;
125}
126
127unsigned paravirt_patch_call(void *target, u16 tgt_clobbers,
128 void *site, u16 site_clobbers,
129 unsigned len)
130{
131 unsigned char *call = site;
132 unsigned long delta = (unsigned long)target - (unsigned long)(call+5);
133
134 if (tgt_clobbers & ~site_clobbers)
135 return len; /* target would clobber too much for this site */
136 if (len < 5)
137 return len; /* call too long for patch site */
139ec7c4 138
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139 *call++ = 0xe8; /* call */
140 *(unsigned long *)call = delta;
139ec7c4 141
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142 return 5;
143}
144
145unsigned paravirt_patch_jmp(void *target, void *site, unsigned len)
146{
147 unsigned char *jmp = site;
148 unsigned long delta = (unsigned long)target - (unsigned long)(jmp+5);
149
150 if (len < 5)
151 return len; /* call too long for patch site */
152
153 *jmp++ = 0xe9; /* jmp */
154 *(unsigned long *)jmp = delta;
155
156 return 5;
157}
158
159unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len)
160{
161 void *opfunc = *((void **)&paravirt_ops + type);
162 unsigned ret;
163
164 if (opfunc == NULL)
165 /* If there's no function, patch it with a ud2a (BUG) */
166 ret = paravirt_patch_insns(site, len, start_ud2a, end_ud2a);
167 else if (opfunc == paravirt_nop)
168 /* If the operation is a nop, then nop the callsite */
169 ret = paravirt_patch_nop();
170 else if (type == PARAVIRT_PATCH(iret) ||
171 type == PARAVIRT_PATCH(irq_enable_sysexit))
172 /* If operation requires a jmp, then jmp */
173 ret = paravirt_patch_jmp(opfunc, site, len);
174 else
175 /* Otherwise call the function; assume target could
176 clobber any caller-save reg */
177 ret = paravirt_patch_call(opfunc, CLBR_ANY,
178 site, clobbers, len);
179
180 return ret;
181}
182
183unsigned paravirt_patch_insns(void *site, unsigned len,
184 const char *start, const char *end)
185{
186 unsigned insn_len = end - start;
139ec7c4 187
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188 if (insn_len > len || start == NULL)
189 insn_len = len;
190 else
191 memcpy(site, start, insn_len);
139ec7c4 192
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193 return insn_len;
194}
195
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196void init_IRQ(void)
197{
198 paravirt_ops.init_IRQ();
199}
200
1a1eecd1 201static void native_flush_tlb(void)
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202{
203 __native_flush_tlb();
204}
205
206/*
207 * Global pages have to be flushed a bit differently. Not a real
208 * performance problem because this does not happen often.
209 */
1a1eecd1 210static void native_flush_tlb_global(void)
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211{
212 __native_flush_tlb_global();
213}
214
63f70270 215static void native_flush_tlb_single(unsigned long addr)
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216{
217 __native_flush_tlb_single(addr);
218}
219
d3561b7f 220/* These are in entry.S */
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221extern void native_iret(void);
222extern void native_irq_enable_sysexit(void);
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223
224static int __init print_banner(void)
225{
226 paravirt_ops.banner();
227 return 0;
228}
229core_initcall(print_banner);
230
231struct paravirt_ops paravirt_ops = {
232 .name = "bare hardware",
233 .paravirt_enabled = 0,
234 .kernel_rpl = 0,
5311ab62 235 .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
d3561b7f 236
139ec7c4 237 .patch = native_patch,
d3561b7f 238 .banner = default_banner,
45876233 239 .arch_setup = paravirt_nop,
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240 .memory_setup = machine_specific_memory_setup,
241 .get_wallclock = native_get_wallclock,
242 .set_wallclock = native_set_wallclock,
e30fab3a 243 .time_init = hpet_time_init,
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244 .init_IRQ = native_init_IRQ,
245
246 .cpuid = native_cpuid,
247 .get_debugreg = native_get_debugreg,
248 .set_debugreg = native_set_debugreg,
249 .clts = native_clts,
250 .read_cr0 = native_read_cr0,
251 .write_cr0 = native_write_cr0,
252 .read_cr2 = native_read_cr2,
253 .write_cr2 = native_write_cr2,
254 .read_cr3 = native_read_cr3,
255 .write_cr3 = native_write_cr3,
256 .read_cr4 = native_read_cr4,
257 .read_cr4_safe = native_read_cr4_safe,
258 .write_cr4 = native_write_cr4,
259 .save_fl = native_save_fl,
260 .restore_fl = native_restore_fl,
261 .irq_disable = native_irq_disable,
262 .irq_enable = native_irq_enable,
263 .safe_halt = native_safe_halt,
264 .halt = native_halt,
265 .wbinvd = native_wbinvd,
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266 .read_msr = native_read_msr_safe,
267 .write_msr = native_write_msr_safe,
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268 .read_tsc = native_read_tsc,
269 .read_pmc = native_read_pmc,
6cb9a835 270 .get_scheduled_cycles = native_read_tsc,
1182d852 271 .get_cpu_khz = native_calculate_cpu_khz,
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272 .load_tr_desc = native_load_tr_desc,
273 .set_ldt = native_set_ldt,
274 .load_gdt = native_load_gdt,
275 .load_idt = native_load_idt,
276 .store_gdt = native_store_gdt,
277 .store_idt = native_store_idt,
278 .store_tr = native_store_tr,
279 .load_tls = native_load_tls,
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280 .write_ldt_entry = write_dt_entry,
281 .write_gdt_entry = write_dt_entry,
282 .write_idt_entry = write_dt_entry,
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283 .load_esp0 = native_load_esp0,
284
285 .set_iopl_mask = native_set_iopl_mask,
286 .io_delay = native_io_delay,
d3561b7f 287
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288#ifdef CONFIG_X86_LOCAL_APIC
289 .apic_write = native_apic_write,
290 .apic_write_atomic = native_apic_write_atomic,
291 .apic_read = native_apic_read,
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292 .setup_boot_clock = setup_boot_APIC_clock,
293 .setup_secondary_clock = setup_secondary_APIC_clock,
13623d79 294#endif
45876233 295 .set_lazy_mode = paravirt_nop,
13623d79 296
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JF
297 .pagetable_setup_start = native_pagetable_setup_start,
298 .pagetable_setup_done = native_pagetable_setup_done,
299
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300 .flush_tlb_user = native_flush_tlb,
301 .flush_tlb_kernel = native_flush_tlb_global,
302 .flush_tlb_single = native_flush_tlb_single,
d4c10477 303 .flush_tlb_others = native_flush_tlb_others,
da181a8b 304
45876233
JF
305 .alloc_pt = paravirt_nop,
306 .alloc_pd = paravirt_nop,
307 .alloc_pd_clone = paravirt_nop,
308 .release_pt = paravirt_nop,
309 .release_pd = paravirt_nop,
c119ecce 310
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311 .set_pte = native_set_pte,
312 .set_pte_at = native_set_pte_at,
313 .set_pmd = native_set_pmd,
45876233
JF
314 .pte_update = paravirt_nop,
315 .pte_update_defer = paravirt_nop,
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316
317 .ptep_get_and_clear = native_ptep_get_and_clear,
318
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319#ifdef CONFIG_X86_PAE
320 .set_pte_atomic = native_set_pte_atomic,
321 .set_pte_present = native_set_pte_present,
322 .set_pud = native_set_pud,
323 .pte_clear = native_pte_clear,
324 .pmd_clear = native_pmd_clear,
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JF
325
326 .pmd_val = native_pmd_val,
327 .make_pmd = native_make_pmd,
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328#endif
329
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JF
330 .pte_val = native_pte_val,
331 .pgd_val = native_pgd_val,
332
333 .make_pte = native_make_pte,
334 .make_pgd = native_make_pgd,
335
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336 .irq_enable_sysexit = native_irq_enable_sysexit,
337 .iret = native_iret,
ae5da273 338
d6dd61c8
JF
339 .dup_mmap = paravirt_nop,
340 .exit_mmap = paravirt_nop,
341 .activate_mm = paravirt_nop,
342
45876233 343 .startup_ipi_hook = paravirt_nop,
d3561b7f 344};
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345
346/*
347 * NOTE: CONFIG_PARAVIRT is experimental and the paravirt_ops
348 * semantics are subject to change. Hence we only do this
349 * internal-only export of this, until it gets sorted out and
350 * all lowlevel CPU ops used by modules are separately exported.
351 */
352EXPORT_SYMBOL_GPL(paravirt_ops);