diff options
Diffstat (limited to 'arch/i386/kernel/paravirt.c')
| -rw-r--r-- | arch/i386/kernel/paravirt.c | 569 |
1 files changed, 569 insertions, 0 deletions
diff --git a/arch/i386/kernel/paravirt.c b/arch/i386/kernel/paravirt.c new file mode 100644 index 00000000000..3dceab5828f --- /dev/null +++ b/arch/i386/kernel/paravirt.c @@ -0,0 +1,569 @@ +/* Paravirtualization interfaces + Copyright (C) 2006 Rusty Russell IBM Corporation + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +*/ +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/efi.h> +#include <linux/bcd.h> +#include <linux/start_kernel.h> + +#include <asm/bug.h> +#include <asm/paravirt.h> +#include <asm/desc.h> +#include <asm/setup.h> +#include <asm/arch_hooks.h> +#include <asm/time.h> +#include <asm/irq.h> +#include <asm/delay.h> +#include <asm/fixmap.h> +#include <asm/apic.h> +#include <asm/tlbflush.h> + +/* nop stub */ +static void native_nop(void) +{ +} + +static void __init default_banner(void) +{ + printk(KERN_INFO "Booting paravirtualized kernel on %s\n", + paravirt_ops.name); +} + +char *memory_setup(void) +{ + return paravirt_ops.memory_setup(); +} + +/* Simple instruction patching code. */ +#define DEF_NATIVE(name, code) \ + extern const char start_##name[], end_##name[]; \ + asm("start_" #name ": " code "; end_" #name ":") +DEF_NATIVE(cli, "cli"); +DEF_NATIVE(sti, "sti"); +DEF_NATIVE(popf, "push %eax; popf"); +DEF_NATIVE(pushf, "pushf; pop %eax"); +DEF_NATIVE(pushf_cli, "pushf; pop %eax; cli"); +DEF_NATIVE(iret, "iret"); +DEF_NATIVE(sti_sysexit, "sti; sysexit"); + +static const struct native_insns +{ + const char *start, *end; +} native_insns[] = { + [PARAVIRT_IRQ_DISABLE] = { start_cli, end_cli }, + [PARAVIRT_IRQ_ENABLE] = { start_sti, end_sti }, + [PARAVIRT_RESTORE_FLAGS] = { start_popf, end_popf }, + [PARAVIRT_SAVE_FLAGS] = { start_pushf, end_pushf }, + [PARAVIRT_SAVE_FLAGS_IRQ_DISABLE] = { start_pushf_cli, end_pushf_cli }, + [PARAVIRT_INTERRUPT_RETURN] = { start_iret, end_iret }, + [PARAVIRT_STI_SYSEXIT] = { start_sti_sysexit, end_sti_sysexit }, +}; + +static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len) +{ + unsigned int insn_len; + + /* Don't touch it if we don't have a replacement */ + if (type >= ARRAY_SIZE(native_insns) || !native_insns[type].start) + return len; + + insn_len = native_insns[type].end - native_insns[type].start; + + /* Similarly if we can't fit replacement. */ + if (len < insn_len) + return len; + + memcpy(insns, native_insns[type].start, insn_len); + return insn_len; +} + +static fastcall unsigned long native_get_debugreg(int regno) +{ + unsigned long val = 0; /* Damn you, gcc! */ + + switch (regno) { + case 0: + asm("movl %%db0, %0" :"=r" (val)); break; + case 1: + asm("movl %%db1, %0" :"=r" (val)); break; + case 2: + asm("movl %%db2, %0" :"=r" (val)); break; + case 3: + asm("movl %%db3, %0" :"=r" (val)); break; + case 6: + asm("movl %%db6, %0" :"=r" (val)); break; + case 7: + asm("movl %%db7, %0" :"=r" (val)); break; + default: + BUG(); + } + return val; +} + +static fastcall void native_set_debugreg(int regno, unsigned long value) +{ + switch (regno) { + case 0: + asm("movl %0,%%db0" : /* no output */ :"r" (value)); + break; + case 1: + asm("movl %0,%%db1" : /* no output */ :"r" (value)); + break; + case 2: + asm("movl %0,%%db2" : /* no output */ :"r" (value)); + break; + case 3: + asm("movl %0,%%db3" : /* no output */ :"r" (value)); + break; + case 6: + asm("movl %0,%%db6" : /* no output */ :"r" (value)); + break; + case 7: + asm("movl %0,%%db7" : /* no output */ :"r" (value)); + break; + default: + BUG(); + } +} + +void init_IRQ(void) +{ + paravirt_ops.init_IRQ(); +} + +static fastcall void native_clts(void) +{ + asm volatile ("clts"); +} + +static fastcall unsigned long native_read_cr0(void) +{ + unsigned long val; + asm volatile("movl %%cr0,%0\n\t" :"=r" (val)); + return val; +} + +static fastcall void native_write_cr0(unsigned long val) +{ + asm volatile("movl %0,%%cr0": :"r" (val)); +} + +static fastcall unsigned long native_read_cr2(void) +{ + unsigned long val; + asm volatile("movl %%cr2,%0\n\t" :"=r" (val)); + return val; +} + +static fastcall void native_write_cr2(unsigned long val) +{ + asm volatile("movl %0,%%cr2": :"r" (val)); +} + +static fastcall unsigned long native_read_cr3(void) +{ + unsigned long val; + asm volatile("movl %%cr3,%0\n\t" :"=r" (val)); + return val; +} + +static fastcall void native_write_cr3(unsigned long val) +{ + asm volatile("movl %0,%%cr3": :"r" (val)); +} + +static fastcall unsigned long native_read_cr4(void) +{ + unsigned long val; + asm volatile("movl %%cr4,%0\n\t" :"=r" (val)); + return val; +} + +static fastcall unsigned long native_read_cr4_safe(void) +{ + unsigned long val; + /* This could fault if %cr4 does not exist */ + asm("1: movl %%cr4, %0 \n" + "2: \n" + ".section __ex_table,\"a\" \n" + ".long 1b,2b \n" + ".previous \n" + : "=r" (val): "0" (0)); + return val; +} + +static fastcall void native_write_cr4(unsigned long val) +{ + asm volatile("movl %0,%%cr4": :"r" (val)); +} + +static fastcall unsigned long native_save_fl(void) +{ + unsigned long f; + asm volatile("pushfl ; popl %0":"=g" (f): /* no input */); + return f; +} + +static fastcall void native_restore_fl(unsigned long f) +{ + asm volatile("pushl %0 ; popfl": /* no output */ + :"g" (f) + :"memory", "cc"); +} + +static fastcall void native_irq_disable(void) +{ + asm volatile("cli": : :"memory"); +} + +static fastcall void native_irq_enable(void) +{ + asm volatile("sti": : :"memory"); +} + +static fastcall void native_safe_halt(void) +{ + asm volatile("sti; hlt": : :"memory"); +} + +static fastcall void native_halt(void) +{ + asm volatile("hlt": : :"memory"); +} + +static fastcall void native_wbinvd(void) +{ + asm volatile("wbinvd": : :"memory"); +} + +static fastcall unsigned long long native_read_msr(unsigned int msr, int *err) +{ + unsigned long long val; + + asm volatile("2: rdmsr ; xorl %0,%0\n" + "1:\n\t" + ".section .fixup,\"ax\"\n\t" + "3: movl %3,%0 ; jmp 1b\n\t" + ".previous\n\t" + ".section __ex_table,\"a\"\n" + " .align 4\n\t" + " .long 2b,3b\n\t" + ".previous" + : "=r" (*err), "=A" (val) + : "c" (msr), "i" (-EFAULT)); + + return val; +} + +static fastcall int native_write_msr(unsigned int msr, unsigned long long val) +{ + int err; + asm volatile("2: wrmsr ; xorl %0,%0\n" + "1:\n\t" + ".section .fixup,\"ax\"\n\t" + "3: movl %4,%0 ; jmp 1b\n\t" + ".previous\n\t" + ".section __ex_table,\"a\"\n" + " .align 4\n\t" + " .long 2b,3b\n\t" + ".previous" + : "=a" (err) + : "c" (msr), "0" ((u32)val), "d" ((u32)(val>>32)), + "i" (-EFAULT)); + return err; +} + +static fastcall unsigned long long native_read_tsc(void) +{ + unsigned long long val; + asm volatile("rdtsc" : "=A" (val)); + return val; +} + +static fastcall unsigned long long native_read_pmc(void) +{ + unsigned long long val; + asm volatile("rdpmc" : "=A" (val)); + return val; +} + +static fastcall void native_load_tr_desc(void) +{ + asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8)); +} + +static fastcall void native_load_gdt(const struct Xgt_desc_struct *dtr) +{ + asm volatile("lgdt %0"::"m" (*dtr)); +} + +static fastcall void native_load_idt(const struct Xgt_desc_struct *dtr) +{ + asm volatile("lidt %0"::"m" (*dtr)); +} + +static fastcall void native_store_gdt(struct Xgt_desc_struct *dtr) +{ + asm ("sgdt %0":"=m" (*dtr)); +} + +static fastcall void native_store_idt(struct Xgt_desc_struct *dtr) +{ + asm ("sidt %0":"=m" (*dtr)); +} + +static fastcall unsigned long native_store_tr(void) +{ + unsigned long tr; + asm ("str %0":"=r" (tr)); + return tr; +} + +static fastcall void native_load_tls(struct thread_struct *t, unsigned int cpu) +{ +#define C(i) get_cpu_gdt_table(cpu)[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i] + C(0); C(1); C(2); +#undef C +} + +static inline void native_write_dt_entry(void *dt, int entry, u32 entry_low, u32 entry_high) +{ + u32 *lp = (u32 *)((char *)dt + entry*8); + lp[0] = entry_low; + lp[1] = entry_high; +} + +static fastcall void native_write_ldt_entry(void *dt, int entrynum, u32 low, u32 high) +{ + native_write_dt_entry(dt, entrynum, low, high); +} + +static fastcall void native_write_gdt_entry(void *dt, int entrynum, u32 low, u32 high) +{ + native_write_dt_entry(dt, entrynum, low, high); +} + +static fastcall void native_write_idt_entry(void *dt, int entrynum, u32 low, u32 high) +{ + native_write_dt_entry(dt, entrynum, low, high); +} + +static fastcall void native_load_esp0(struct tss_struct *tss, + struct thread_struct *thread) +{ + tss->esp0 = thread->esp0; + + /* This can only happen when SEP is enabled, no need to test "SEP"arately */ + if (unlikely(tss->ss1 != thread->sysenter_cs)) { + tss->ss1 = thread->sysenter_cs; + wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0); + } +} + +static fastcall void native_io_delay(void) +{ + asm volatile("outb %al,$0x80"); +} + +static fastcall void native_flush_tlb(void) +{ + __native_flush_tlb(); +} + +/* + * Global pages have to be flushed a bit differently. Not a real + * performance problem because this does not happen often. + */ +static fastcall void native_flush_tlb_global(void) +{ + __native_flush_tlb_global(); +} + +static fastcall void native_flush_tlb_single(u32 addr) +{ + __native_flush_tlb_single(addr); +} + +#ifndef CONFIG_X86_PAE +static fastcall void native_set_pte(pte_t *ptep, pte_t pteval) +{ + *ptep = pteval; +} + +static fastcall void native_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval) +{ + *ptep = pteval; +} + +static fastcall void native_set_pmd(pmd_t *pmdp, pmd_t pmdval) +{ + *pmdp = pmdval; +} + +#else /* CONFIG_X86_PAE */ + +static fastcall void native_set_pte(pte_t *ptep, pte_t pte) +{ + ptep->pte_high = pte.pte_high; + smp_wmb(); + ptep->pte_low = pte.pte_low; +} + +static fastcall void native_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pte) +{ + ptep->pte_high = pte.pte_high; + smp_wmb(); + ptep->pte_low = pte.pte_low; +} + +static fastcall void native_set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) +{ + ptep->pte_low = 0; + smp_wmb(); + ptep->pte_high = pte.pte_high; + smp_wmb(); + ptep->pte_low = pte.pte_low; +} + +static fastcall void native_set_pte_atomic(pte_t *ptep, pte_t pteval) +{ + set_64bit((unsigned long long *)ptep,pte_val(pteval)); +} + +static fastcall void native_set_pmd(pmd_t *pmdp, pmd_t pmdval) +{ + set_64bit((unsigned long long *)pmdp,pmd_val(pmdval)); +} + +static fastcall void native_set_pud(pud_t *pudp, pud_t pudval) +{ + *pudp = pudval; +} + +static fastcall void native_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) +{ + ptep->pte_low = 0; + smp_wmb(); + ptep->pte_high = 0; +} + +static fastcall void native_pmd_clear(pmd_t *pmd) +{ + u32 *tmp = (u32 *)pmd; + *tmp = 0; + smp_wmb(); + *(tmp + 1) = 0; +} +#endif /* CONFIG_X86_PAE */ + +/* These are in entry.S */ +extern fastcall void native_iret(void); +extern fastcall void native_irq_enable_sysexit(void); + +static int __init print_banner(void) +{ + paravirt_ops.banner(); + return 0; +} +core_initcall(print_banner); + +/* We simply declare start_kernel to be the paravirt probe of last resort. */ +paravirt_probe(start_kernel); + +struct paravirt_ops paravirt_ops = { + .name = "bare hardware", + .paravirt_enabled = 0, + .kernel_rpl = 0, + + .patch = native_patch, + .banner = default_banner, + .arch_setup = native_nop, + .memory_setup = machine_specific_memory_setup, + .get_wallclock = native_get_wallclock, + .set_wallclock = native_set_wallclock, + .time_init = time_init_hook, + .init_IRQ = native_init_IRQ, + + .cpuid = native_cpuid, + .get_debugreg = native_get_debugreg, + .set_debugreg = native_set_debugreg, + .clts = native_clts, + .read_cr0 = native_read_cr0, + .write_cr0 = native_write_cr0, + .read_cr2 = native_read_cr2, + .write_cr2 = native_write_cr2, + .read_cr3 = native_read_cr3, + .write_cr3 = native_write_cr3, + .read_cr4 = native_read_cr4, + .read_cr4_safe = native_read_cr4_safe, + .write_cr4 = native_write_cr4, + .save_fl = native_save_fl, + .restore_fl = native_restore_fl, + .irq_disable = native_irq_disable, + .irq_enable = native_irq_enable, + .safe_halt = native_safe_halt, + .halt = native_halt, + .wbinvd = native_wbinvd, + .read_msr = native_read_msr, + .write_msr = native_write_msr, + .read_tsc = native_read_tsc, + .read_pmc = native_read_pmc, + .load_tr_desc = native_load_tr_desc, + .set_ldt = native_set_ldt, + .load_gdt = native_load_gdt, + .load_idt = native_load_idt, + .store_gdt = native_store_gdt, + .store_idt = native_store_idt, + .store_tr = native_store_tr, + .load_tls = native_load_tls, + .write_ldt_entry = native_write_ldt_entry, + .write_gdt_entry = native_write_gdt_entry, + .write_idt_entry = native_write_idt_entry, + .load_esp0 = native_load_esp0, + + .set_iopl_mask = native_set_iopl_mask, + .io_delay = native_io_delay, + .const_udelay = __const_udelay, + +#ifdef CONFIG_X86_LOCAL_APIC + .apic_write = native_apic_write, + .apic_write_atomic = native_apic_write_atomic, + .apic_read = native_apic_read, +#endif + + .flush_tlb_user = native_flush_tlb, + .flush_tlb_kernel = native_flush_tlb_global, + .flush_tlb_single = native_flush_tlb_single, + + .set_pte = native_set_pte, + .set_pte_at = native_set_pte_at, + .set_pmd = native_set_pmd, + .pte_update = (void *)native_nop, + .pte_update_defer = (void *)native_nop, +#ifdef CONFIG_X86_PAE + .set_pte_atomic = native_set_pte_atomic, + .set_pte_present = native_set_pte_present, + .set_pud = native_set_pud, + .pte_clear = native_pte_clear, + .pmd_clear = native_pmd_clear, +#endif + + .irq_enable_sysexit = native_irq_enable_sysexit, + .iret = native_iret, +}; +EXPORT_SYMBOL(paravirt_ops); |