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> 22#include <linux/highmem.h> 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> 32#include <asm/fixmap.h> 33#include <asm/apic.h> 34#include <asm/tlbflush.h> 35#include <asm/timer.h> 36 37/* nop stub */ 38void _paravirt_nop(void) 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 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 ":") 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"); 62DEF_NATIVE(iret, "iret"); 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"); 69 70DEF_NATIVE(ud2a, "ud2a"); 71 72static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len) 73{ 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 */ 138 139 *call++ = 0xe8; /* call */ 140 *(unsigned long *)call = delta; 141 142 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 **)¶virt_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; 187 188 if (insn_len > len || start == NULL) 189 insn_len = len; 190 else 191 memcpy(site, start, insn_len); 192 193 return insn_len; 194} 195 196void init_IRQ(void) 197{ 198 paravirt_ops.init_IRQ(); 199} 200 201static void native_flush_tlb(void) 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 */ 210static void native_flush_tlb_global(void) 211{ 212 __native_flush_tlb_global(); 213} 214 215static void native_flush_tlb_single(unsigned long addr) 216{ 217 __native_flush_tlb_single(addr); 218} 219 220/* These are in entry.S */ 221extern void native_iret(void); 222extern void native_irq_enable_sysexit(void); 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, 235 .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */ 236 237 .patch = native_patch, 238 .banner = default_banner, 239 .arch_setup = paravirt_nop, 240 .memory_setup = machine_specific_memory_setup, 241 .get_wallclock = native_get_wallclock, 242 .set_wallclock = native_set_wallclock, 243 .time_init = hpet_time_init, 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, 266 .read_msr = native_read_msr_safe, 267 .write_msr = native_write_msr_safe, 268 .read_tsc = native_read_tsc, 269 .read_pmc = native_read_pmc, 270 .get_scheduled_cycles = native_read_tsc, 271 .get_cpu_khz = native_calculate_cpu_khz, 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, 280 .write_ldt_entry = write_dt_entry, 281 .write_gdt_entry = write_dt_entry, 282 .write_idt_entry = write_dt_entry, 283 .load_esp0 = native_load_esp0, 284 285 .set_iopl_mask = native_set_iopl_mask, 286 .io_delay = native_io_delay, 287 288#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, 292 .setup_boot_clock = setup_boot_APIC_clock, 293 .setup_secondary_clock = setup_secondary_APIC_clock, 294 .startup_ipi_hook = paravirt_nop, 295#endif 296 .set_lazy_mode = paravirt_nop, 297 298 .pagetable_setup_start = native_pagetable_setup_start, 299 .pagetable_setup_done = native_pagetable_setup_done, 300 301 .flush_tlb_user = native_flush_tlb, 302 .flush_tlb_kernel = native_flush_tlb_global, 303 .flush_tlb_single = native_flush_tlb_single, 304 .flush_tlb_others = native_flush_tlb_others, 305 306 .alloc_pt = paravirt_nop, 307 .alloc_pd = paravirt_nop, 308 .alloc_pd_clone = paravirt_nop, 309 .release_pt = paravirt_nop, 310 .release_pd = paravirt_nop, 311 312 .set_pte = native_set_pte, 313 .set_pte_at = native_set_pte_at, 314 .set_pmd = native_set_pmd, 315 .pte_update = paravirt_nop, 316 .pte_update_defer = paravirt_nop, 317 318#ifdef CONFIG_HIGHPTE 319 .kmap_atomic_pte = kmap_atomic, 320#endif 321 322#ifdef CONFIG_X86_PAE 323 .set_pte_atomic = native_set_pte_atomic, 324 .set_pte_present = native_set_pte_present, 325 .set_pud = native_set_pud, 326 .pte_clear = native_pte_clear, 327 .pmd_clear = native_pmd_clear, 328 329 .pmd_val = native_pmd_val, 330 .make_pmd = native_make_pmd, 331#endif 332 333 .pte_val = native_pte_val, 334 .pgd_val = native_pgd_val, 335 336 .make_pte = native_make_pte, 337 .make_pgd = native_make_pgd, 338 339 .irq_enable_sysexit = native_irq_enable_sysexit, 340 .iret = native_iret, 341 342 .dup_mmap = paravirt_nop, 343 .exit_mmap = paravirt_nop, 344 .activate_mm = paravirt_nop, 345}; 346 347EXPORT_SYMBOL(paravirt_ops); 348