/* 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/highmem.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(irq_disable, "cli");
DEF_NATIVE(irq_enable, "sti");
DEF_NATIVE(restore_fl, "push %eax; popf");
DEF_NATIVE(save_fl, "pushf; pop %eax");
DEF_NATIVE(iret, "iret");
DEF_NATIVE(irq_enable_sysexit, "sti; sysexit");
DEF_NATIVE(read_cr2, "mov %cr2, %eax");
DEF_NATIVE(write_cr3, "mov %eax, %cr3");
DEF_NATIVE(read_cr3, "mov %cr3, %eax");
DEF_NATIVE(clts, "clts");
DEF_NATIVE(read_tsc, "rdtsc");
DEF_NATIVE(ud2a, "ud2a");
static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len)
{
const unsigned char *start, *end;
unsigned ret;
switch(type) {
#define SITE(x) case PARAVIRT_PATCH(x): start = start_##x; end = end_##x; goto patch_site
SITE(irq_disable);
SITE(irq_enable);
SITE(restore_fl);
SITE(save_fl);
SITE(iret);
SITE(irq_enable_sysexit);
SITE(read_cr2);
SITE(read_cr3);
SITE(write_cr3);
SITE(clts);
SITE(read_tsc);
#undef SITE
patch_site:
ret = paravirt_patch_insns(insns, len, start, end);
break;
case PARAVIRT_PATCH(make_pgd):
case PARAVIRT_PATCH(make_pte):
case PARAVIRT_PATCH(pgd_val):
case PARAVIRT_PATCH(pte_val):
#ifdef CONFIG_X86_PAE
case PARAVIRT_PATCH(make_pmd):
case PARAVIRT_PATCH(pmd_val):
#endif
/* These functions end up returning exactly what
they're passed, in the same registers. */
ret = paravirt_patch_nop();
break;
default:
ret = paravirt_patch_default(type, clobbers, insns, len);
break;
}
return ret;
}
unsigned paravirt_patch_nop(void)
{
return 0;
}
unsigned paravirt_patch_ignore(unsigned len)
{
return len;
}
struct branch {
unsigned char opcode;
u32 delta;
} __attribute__((packed));
unsigned paravirt_patch_call(void *target, u16 tgt_clobbers,
void *site, u16 site_clobbers,
unsigned len)
{
unsigned char *call = site;
unsigned long delta = (unsigned long)target - (unsigned long)(call+5);
struct branch b;
if (tgt_clobbers & ~site_clobbers)
return len; /* target would clobber too much for this site */
if (len < 5)
return len; /* call too long for patch site */
b.opcode = 0xe8; /* call */
b.delta = delta;
BUILD_BUG_ON(sizeof(b) != 5);
text_poke(call, (unsigned char *)&b, 5);
return 5;
}
unsigned paravirt_patch_jmp(void *target, void *site, unsigned len)
{
unsigned char *jmp = site;
unsigned long delta = (unsigned long)target - (unsigned long)(jmp+5);
struct branch b;
if (len < 5)
return len; /* call too long for patch site */
b.opcode = 0xe9; /* jmp */
b.delta = delta;
text_poke(jmp, (unsigned char *)&b, 5);
return 5;
}
unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len)
{
void *opfunc = *((void **)¶virt_ops + type);
unsigned ret;
if (opfunc == NULL)
/* If there's no function, patch it with a ud2a (BUG) */
ret = paravirt_patch_insns(site, len, start_ud2a, end_ud2a);
else if (opfunc == paravirt_nop)
/* If the operation is a nop, then nop the callsite */
ret = paravirt_patch_nop();
else if (type == PARAVIRT_PATCH(iret) ||
type == PARAVIRT_PATCH(irq_enable_sysexit))
/* If operation requires a jmp, then jmp */
ret = paravirt_patch_jmp(opfunc, site, len);
else
/* Otherwise call the function; assume target could
clobber any caller-save reg */
ret = paravirt_patch_call(opfunc, CLBR_ANY,
site, clobbers, len);
return ret;
}
unsigned paravirt_patch_insns(void *site, unsigned len,
const char *start, const char *end)
{
unsigned insn_len = end - start;
if (insn_len > len || start == NULL)
insn_len = len;
else
memcpy(site, 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(unsigned long 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);
static struct resource reserve_ioports = {
.start = 0,
.end = IO_SPACE_LIMIT,
.name = "paravirt-ioport",
.flags = IORESOURCE_IO | IORESOURCE_BUSY,
};
static struct resource reserve_iomem = {
.start = 0,
.end = -1,
.name = "paravirt-iomem",
.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
};
/*
* Reserve the whole legacy IO space to prevent any legacy drivers
* from wasting time probing for their hardware. This is a fairly
* brute-force approach to disabling all non-virtual drivers.
*
* Note that this must be called very early to have any effect.
*/
int paravirt_disable_iospace(void)
{
int ret;
ret = request_resource(&ioport_resource, &reserve_ioports);
if (ret == 0) {
ret = request_resource(&iomem_resource, &reserve_iomem);
if (ret)
release_resource(&reserve_ioports);
}
return ret;
}
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,
.sched_clock = native_sched_clock,
.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,
.startup_ipi_hook = paravirt_nop,
#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,
.flush_tlb_others = native_flush_tlb_others,
.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,
#ifdef CONFIG_HIGHPTE
.kmap_atomic_pte = kmap_atomic,
#endif
#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,
};
EXPORT_SYMBOL(paravirt_ops);
