arch/i386/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 #include <linux/errno.h>
  19 #include <linux/module.h>
  20 #include <linux/efi.h>
  21 #include <linux/bcd.h>
  22 #include <linux/start_kernel.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 */
  38 void _paravirt_nop(void)
  39 {
  40 }
  41
  42 static void __init default_banner(void)
  43 {
  44         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
  45                paravirt_ops.name);
  46 }
  47
  48 char *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 DEF_NATIVE(cli, "cli");
  58 DEF_NATIVE(sti, "sti");
  59 DEF_NATIVE(popf, "push %eax; popf");
  60 DEF_NATIVE(pushf, "pushf; pop %eax");
  61 DEF_NATIVE(pushf_cli, "pushf; pop %eax; cli");
  62 DEF_NATIVE(iret, "iret");
  63 DEF_NATIVE(sti_sysexit, "sti; sysexit");
  64
  65 static const struct native_insns
  66 {
  67         const char *start, *end;
  68 } native_insns[] = {
  69         [PARAVIRT_IRQ_DISABLE] = { start_cli, end_cli },
  70         [PARAVIRT_IRQ_ENABLE] = { start_sti, end_sti },
  71         [PARAVIRT_RESTORE_FLAGS] = { start_popf, end_popf },
  72         [PARAVIRT_SAVE_FLAGS] = { start_pushf, end_pushf },
  73         [PARAVIRT_SAVE_FLAGS_IRQ_DISABLE] = { start_pushf_cli, end_pushf_cli },
  74         [PARAVIRT_INTERRUPT_RETURN] = { start_iret, end_iret },
  75         [PARAVIRT_STI_SYSEXIT] = { start_sti_sysexit, end_sti_sysexit },
  76 };
  77
  78 static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len)
  79 {
  80         unsigned int insn_len;
  81
  82         /* Don't touch it if we don't have a replacement */
  83         if (type >= ARRAY_SIZE(native_insns) || !native_insns[type].start)
  84                 return len;
  85
  86         insn_len = native_insns[type].end - native_insns[type].start;
  87
  88         /* Similarly if we can't fit replacement. */
  89         if (len < insn_len)
  90                 return len;
  91
  92         memcpy(insns, native_insns[type].start, insn_len);
  93         return insn_len;
  94 }
  95
  96 void init_IRQ(void)
  97 {
  98         paravirt_ops.init_IRQ();
  99 }
 100
 101 static void native_flush_tlb(void)
 102 {
 103         __native_flush_tlb();
 104 }
 105
 106 /*
 107  * Global pages have to be flushed a bit differently. Not a real
 108  * performance problem because this does not happen often.
 109  */
 110 static void native_flush_tlb_global(void)
 111 {
 112         __native_flush_tlb_global();
 113 }
 114
 115 static void native_flush_tlb_single(u32 addr)
 116 {
 117         __native_flush_tlb_single(addr);
 118 }
 119
 120 /* These are in entry.S */
 121 extern void native_iret(void);
 122 extern void native_irq_enable_sysexit(void);
 123
 124 static int __init print_banner(void)
 125 {
 126         paravirt_ops.banner();
 127         return 0;
 128 }
 129 core_initcall(print_banner);
 130
 131 struct paravirt_ops paravirt_ops = {
 132         .name = "bare hardware",
 133         .paravirt_enabled = 0,
 134         .kernel_rpl = 0,
 135         .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
 136
 137         .patch = native_patch,
 138         .banner = default_banner,
 139         .arch_setup = paravirt_nop,
 140         .memory_setup = machine_specific_memory_setup,
 141         .get_wallclock = native_get_wallclock,
 142         .set_wallclock = native_set_wallclock,
 143         .time_init = hpet_time_init,
 144         .init_IRQ = native_init_IRQ,
 145
 146         .cpuid = native_cpuid,
 147         .get_debugreg = native_get_debugreg,
 148         .set_debugreg = native_set_debugreg,
 149         .clts = native_clts,
 150         .read_cr0 = native_read_cr0,
 151         .write_cr0 = native_write_cr0,
 152         .read_cr2 = native_read_cr2,
 153         .write_cr2 = native_write_cr2,
 154         .read_cr3 = native_read_cr3,
 155         .write_cr3 = native_write_cr3,
 156         .read_cr4 = native_read_cr4,
 157         .read_cr4_safe = native_read_cr4_safe,
 158         .write_cr4 = native_write_cr4,
 159         .save_fl = native_save_fl,
 160         .restore_fl = native_restore_fl,
 161         .irq_disable = native_irq_disable,
 162         .irq_enable = native_irq_enable,
 163         .safe_halt = native_safe_halt,
 164         .halt = native_halt,
 165         .wbinvd = native_wbinvd,
 166         .read_msr = native_read_msr_safe,
 167         .write_msr = native_write_msr_safe,
 168         .read_tsc = native_read_tsc,
 169         .read_pmc = native_read_pmc,
 170         .get_scheduled_cycles = native_read_tsc,
 171         .get_cpu_khz = native_calculate_cpu_khz,
 172         .load_tr_desc = native_load_tr_desc,
 173         .set_ldt = native_set_ldt,
 174         .load_gdt = native_load_gdt,
 175         .load_idt = native_load_idt,
 176         .store_gdt = native_store_gdt,
 177         .store_idt = native_store_idt,
 178         .store_tr = native_store_tr,
 179         .load_tls = native_load_tls,
 180         .write_ldt_entry = write_dt_entry,
 181         .write_gdt_entry = write_dt_entry,
 182         .write_idt_entry = write_dt_entry,
 183         .load_esp0 = native_load_esp0,
 184
 185         .set_iopl_mask = native_set_iopl_mask,
 186         .io_delay = native_io_delay,
 187
 188 #ifdef CONFIG_X86_LOCAL_APIC
 189         .apic_write = native_apic_write,
 190         .apic_write_atomic = native_apic_write_atomic,
 191         .apic_read = native_apic_read,
 192         .setup_boot_clock = setup_boot_APIC_clock,
 193         .setup_secondary_clock = setup_secondary_APIC_clock,
 194 #endif
 195         .set_lazy_mode = paravirt_nop,
 196
 197         .pagetable_setup_start = native_pagetable_setup_start,
 198         .pagetable_setup_done = native_pagetable_setup_done,
 199
 200         .flush_tlb_user = native_flush_tlb,
 201         .flush_tlb_kernel = native_flush_tlb_global,
 202         .flush_tlb_single = native_flush_tlb_single,
 203
 204         .map_pt_hook = paravirt_nop,
 205
 206         .alloc_pt = paravirt_nop,
 207         .alloc_pd = paravirt_nop,
 208         .alloc_pd_clone = paravirt_nop,
 209         .release_pt = paravirt_nop,
 210         .release_pd = paravirt_nop,
 211
 212         .set_pte = native_set_pte,
 213         .set_pte_at = native_set_pte_at,
 214         .set_pmd = native_set_pmd,
 215         .pte_update = paravirt_nop,
 216         .pte_update_defer = paravirt_nop,
 217
 218         .ptep_get_and_clear = native_ptep_get_and_clear,
 219
 220 #ifdef CONFIG_X86_PAE
 221         .set_pte_atomic = native_set_pte_atomic,
 222         .set_pte_present = native_set_pte_present,
 223         .set_pud = native_set_pud,
 224         .pte_clear = native_pte_clear,
 225         .pmd_clear = native_pmd_clear,
 226
 227         .pmd_val = native_pmd_val,
 228         .make_pmd = native_make_pmd,
 229 #endif
 230
 231         .pte_val = native_pte_val,
 232         .pgd_val = native_pgd_val,
 233
 234         .make_pte = native_make_pte,
 235         .make_pgd = native_make_pgd,
 236
 237         .irq_enable_sysexit = native_irq_enable_sysexit,
 238         .iret = native_iret,
 239
 240         .startup_ipi_hook = paravirt_nop,
 241 };
 242
 243 /*
 244  * NOTE: CONFIG_PARAVIRT is experimental and the paravirt_ops
 245  * semantics are subject to change. Hence we only do this
 246  * internal-only export of this, until it gets sorted out and
 247  * all lowlevel CPU ops used by modules are separately exported.
 248  */
 249 EXPORT_SYMBOL_GPL(paravirt_ops);