linux/arch/i386/kernel/paravirt.c
Zachary Amsden e30fab3ad3 [PATCH] vmi: pit override
The time_init_hook in paravirt-ops no longer functions in the correct manner
after the integration of the hrtimers code.  The problem is that now the call
path for time initialization is:

  time_init :
       late_time_init = hpet_time_init;

  late_time_init -> hpet_time_init:
       setup_pit_timer (BAD)
       do_time_init --> (via paravirt.h)
          time_init_hook --> (via arch_hooks.h)
              time_init_hook (in SUBARCH/setup.c)

If this isn't confusing enough, the paravirt case goes through an indirect
function pointer in the paravirt-ops table.  The problem is, by the time the
paravirt hook is called, the pit timer is already enabled.

But paravirt guests have their own timer, and don't want to use the PIT.
Rather than intensify the struggle for power going on here, just make it all
nice and simple and just unconditionally do all timer setup in the
late_time_init hook.  This also has the advantage of enabling timers in the
same place in all code paths, so everyone has the same bugs and we don't have
outliers who break other code because they turn on timer too early or too
late.

So the paravirt-ops time init function is now by default hpet_time_init, which
is the time init function used for native hardware.  Paravirt guests have the
chance to override this when they setup the paravirt-ops table, and should
need no change.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 07:57:52 -08:00

589 lines
14 KiB
C

/* 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>
#include <asm/timer.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 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 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 void native_clts(void)
{
asm volatile ("clts");
}
static unsigned long native_read_cr0(void)
{
unsigned long val;
asm volatile("movl %%cr0,%0\n\t" :"=r" (val));
return val;
}
static void native_write_cr0(unsigned long val)
{
asm volatile("movl %0,%%cr0": :"r" (val));
}
static unsigned long native_read_cr2(void)
{
unsigned long val;
asm volatile("movl %%cr2,%0\n\t" :"=r" (val));
return val;
}
static void native_write_cr2(unsigned long val)
{
asm volatile("movl %0,%%cr2": :"r" (val));
}
static unsigned long native_read_cr3(void)
{
unsigned long val;
asm volatile("movl %%cr3,%0\n\t" :"=r" (val));
return val;
}
static void native_write_cr3(unsigned long val)
{
asm volatile("movl %0,%%cr3": :"r" (val));
}
static unsigned long native_read_cr4(void)
{
unsigned long val;
asm volatile("movl %%cr4,%0\n\t" :"=r" (val));
return val;
}
static 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 void native_write_cr4(unsigned long val)
{
asm volatile("movl %0,%%cr4": :"r" (val));
}
static unsigned long native_save_fl(void)
{
unsigned long f;
asm volatile("pushfl ; popl %0":"=g" (f): /* no input */);
return f;
}
static void native_restore_fl(unsigned long f)
{
asm volatile("pushl %0 ; popfl": /* no output */
:"g" (f)
:"memory", "cc");
}
static void native_irq_disable(void)
{
asm volatile("cli": : :"memory");
}
static void native_irq_enable(void)
{
asm volatile("sti": : :"memory");
}
static void native_safe_halt(void)
{
asm volatile("sti; hlt": : :"memory");
}
static void native_halt(void)
{
asm volatile("hlt": : :"memory");
}
static void native_wbinvd(void)
{
asm volatile("wbinvd": : :"memory");
}
static 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 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 unsigned long long native_read_tsc(void)
{
unsigned long long val;
asm volatile("rdtsc" : "=A" (val));
return val;
}
static unsigned long long native_read_pmc(void)
{
unsigned long long val;
asm volatile("rdpmc" : "=A" (val));
return val;
}
static void native_load_tr_desc(void)
{
asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8));
}
static void native_load_gdt(const struct Xgt_desc_struct *dtr)
{
asm volatile("lgdt %0"::"m" (*dtr));
}
static void native_load_idt(const struct Xgt_desc_struct *dtr)
{
asm volatile("lidt %0"::"m" (*dtr));
}
static void native_store_gdt(struct Xgt_desc_struct *dtr)
{
asm ("sgdt %0":"=m" (*dtr));
}
static void native_store_idt(struct Xgt_desc_struct *dtr)
{
asm ("sidt %0":"=m" (*dtr));
}
static unsigned long native_store_tr(void)
{
unsigned long tr;
asm ("str %0":"=r" (tr));
return tr;
}
static 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 void native_write_ldt_entry(void *dt, int entrynum, u32 low, u32 high)
{
native_write_dt_entry(dt, entrynum, low, high);
}
static void native_write_gdt_entry(void *dt, int entrynum, u32 low, u32 high)
{
native_write_dt_entry(dt, entrynum, low, high);
}
static void native_write_idt_entry(void *dt, int entrynum, u32 low, u32 high)
{
native_write_dt_entry(dt, entrynum, low, high);
}
static 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 void native_io_delay(void)
{
asm volatile("outb %al,$0x80");
}
static 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 void native_flush_tlb_global(void)
{
__native_flush_tlb_global();
}
static void native_flush_tlb_single(u32 addr)
{
__native_flush_tlb_single(addr);
}
#ifndef CONFIG_X86_PAE
static void native_set_pte(pte_t *ptep, pte_t pteval)
{
*ptep = pteval;
}
static void native_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval)
{
*ptep = pteval;
}
static void native_set_pmd(pmd_t *pmdp, pmd_t pmdval)
{
*pmdp = pmdval;
}
#else /* CONFIG_X86_PAE */
static 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 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 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 void native_set_pte_atomic(pte_t *ptep, pte_t pteval)
{
set_64bit((unsigned long long *)ptep,pte_val(pteval));
}
static void native_set_pmd(pmd_t *pmdp, pmd_t pmdval)
{
set_64bit((unsigned long long *)pmdp,pmd_val(pmdval));
}
static void native_set_pud(pud_t *pudp, pud_t pudval)
{
*pudp = pudval;
}
static 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 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 void native_iret(void);
extern void native_irq_enable_sysexit(void);
static int __init print_banner(void)
{
paravirt_ops.banner();
return 0;
}
core_initcall(print_banner);
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 = hpet_time_init,
.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,
.get_scheduled_cycles = native_read_tsc,
.get_cpu_khz = native_calculate_cpu_khz,
.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,
#ifdef CONFIG_X86_LOCAL_APIC
.apic_write = native_apic_write,
.apic_write_atomic = native_apic_write_atomic,
.apic_read = native_apic_read,
.setup_boot_clock = setup_boot_APIC_clock,
.setup_secondary_clock = setup_secondary_APIC_clock,
#endif
.set_lazy_mode = (void *)native_nop,
.flush_tlb_user = native_flush_tlb,
.flush_tlb_kernel = native_flush_tlb_global,
.flush_tlb_single = native_flush_tlb_single,
.map_pt_hook = (void *)native_nop,
.alloc_pt = (void *)native_nop,
.alloc_pd = (void *)native_nop,
.alloc_pd_clone = (void *)native_nop,
.release_pt = (void *)native_nop,
.release_pd = (void *)native_nop,
.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,
.startup_ipi_hook = (void *)native_nop,
};
/*
* NOTE: CONFIG_PARAVIRT is experimental and the paravirt_ops
* semantics are subject to change. Hence we only do this
* internal-only export of this, until it gets sorted out and
* all lowlevel CPU ops used by modules are separately exported.
*/
EXPORT_SYMBOL_GPL(paravirt_ops);