arch/i386/kernel/paravirt.c - linux - Git at Google

 /*  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 <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;
 }

 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);

 	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 */

 	*call++ = 0xe8;		/* call */
 	*(unsigned long *)call = delta;

 	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);

 	if (len < 5)
 		return len;	/* call too long for patch site */

 	*jmp++ = 0xe9;		/* jmp */
 	*(unsigned long *)jmp = delta;

 	return 5;
 }

 unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len)
 {
 	void *opfunc = *((void **)&paravirt_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);

 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,
 	.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);
	/* 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 <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;
	}

	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);

	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 */

	call++ = 0xe8; / call */
	(unsigned long )call = delta;

	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);

	if (len < 5)
	return len; /* call too long for patch site */

	jmp++ = 0xe9; / jmp */
	(unsigned long )jmp = delta;

	return 5;
	}

	unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len)
	{
	void opfunc = ((void **)&paravirt_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);

	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,
	.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);