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linux/arch/i386/kernel/paravirt.c
Jeremy Fitzhardinge d582203578 [PATCH] i386: PARAVIRT: Use patch site IDs computed from offset in paravirt_ops structure
Use patch type identifiers derived from the offset of the operation in
the paravirt_ops structure.  This avoids having to maintain a separate
enum for patch site types.

Also, since the identifier is derived from the offset into
paravirt_ops, the offset can be derived from the identifier.  This is
used to remove replicated information in the various callsite macros,
which has been a source of bugs in the past.

This patch also drops the fused save_fl+cli operation, which doesn't
really add much and makes things more complex - specifically because
it breaks the 1:1 relationship between identifiers and offsets.  If
this operation turns out to be particularly beneficial, then the right
answer is to define a new entrypoint for it.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
2007-05-02 19:27:14 +02:00

252 lines
6.7 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 */
void _paravirt_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(iret, "iret");
DEF_NATIVE(sti_sysexit, "sti; sysexit");
static const struct native_insns
{
const char *start, *end;
} native_insns[] = {
[PARAVIRT_PATCH(irq_disable)] = { start_cli, end_cli },
[PARAVIRT_PATCH(irq_enable)] = { start_sti, end_sti },
[PARAVIRT_PATCH(restore_fl)] = { start_popf, end_popf },
[PARAVIRT_PATCH(save_fl)] = { start_pushf, end_pushf },
[PARAVIRT_PATCH(iret)] = { start_iret, end_iret },
[PARAVIRT_PATCH(irq_enable_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;
}
void init_IRQ(void)
{
paravirt_ops.init_IRQ();
}
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);
}
/* 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,
.shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
.patch = native_patch,
.banner = default_banner,
.arch_setup = paravirt_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_safe,
.write_msr = native_write_msr_safe,
.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 = write_dt_entry,
.write_gdt_entry = write_dt_entry,
.write_idt_entry = write_dt_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 = paravirt_nop,
.pagetable_setup_start = native_pagetable_setup_start,
.pagetable_setup_done = native_pagetable_setup_done,
.flush_tlb_user = native_flush_tlb,
.flush_tlb_kernel = native_flush_tlb_global,
.flush_tlb_single = native_flush_tlb_single,
.map_pt_hook = paravirt_nop,
.alloc_pt = paravirt_nop,
.alloc_pd = paravirt_nop,
.alloc_pd_clone = paravirt_nop,
.release_pt = paravirt_nop,
.release_pd = paravirt_nop,
.set_pte = native_set_pte,
.set_pte_at = native_set_pte_at,
.set_pmd = native_set_pmd,
.pte_update = paravirt_nop,
.pte_update_defer = paravirt_nop,
.ptep_get_and_clear = native_ptep_get_and_clear,
#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,
.pmd_val = native_pmd_val,
.make_pmd = native_make_pmd,
#endif
.pte_val = native_pte_val,
.pgd_val = native_pgd_val,
.make_pte = native_make_pte,
.make_pgd = native_make_pgd,
.irq_enable_sysexit = native_irq_enable_sysexit,
.iret = native_iret,
.dup_mmap = paravirt_nop,
.exit_mmap = paravirt_nop,
.activate_mm = paravirt_nop,
.startup_ipi_hook = paravirt_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);