Release 4.14 arch/x86/include/asm/special_insns.h

Directory: arch/x86/include/asm
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_SPECIAL_INSNS_H

#define _ASM_X86_SPECIAL_INSNS_H


#ifdef __KERNEL__

#include <asm/nops.h>

/*
 * Volatile isn't enough to prevent the compiler from reordering the
 * read/write functions for the control registers and messing everything up.
 * A memory clobber would solve the problem, but would prevent reordering of
 * all loads stores around it, which can hurt performance. Solution is to
 * use a variable and mimic reads and writes to it to enforce serialization
 */
extern unsigned long __force_order;



static inline unsigned long native_read_cr0(void)
{
	unsigned long val;
	asm volatile("mov %%cr0,%0\n\t" : "=r" (val), "=m" (__force_order));
	return val;
}

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David Howells 20 100.00% 1 100.00%
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static inline void native_write_cr0(unsigned long val)
{
	asm volatile("mov %0,%%cr0": : "r" (val), "m" (__force_order));
}

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David Howells 14 100.00% 1 100.00%
Total 14 100.00% 1 100.00%



static inline unsigned long native_read_cr2(void)
{
	unsigned long val;
	asm volatile("mov %%cr2,%0\n\t" : "=r" (val), "=m" (__force_order));
	return val;
}

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David Howells 20 100.00% 1 100.00%
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static inline void native_write_cr2(unsigned long val)
{
	asm volatile("mov %0,%%cr2": : "r" (val), "m" (__force_order));
}

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David Howells 14 100.00% 1 100.00%
Total 14 100.00% 1 100.00%



static inline unsigned long __native_read_cr3(void)
{
	unsigned long val;
	asm volatile("mov %%cr3,%0\n\t" : "=r" (val), "=m" (__force_order));
	return val;
}

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David Howells 19 95.00% 1 50.00%
Andrew Lutomirski 1 5.00% 1 50.00%
Total 20 100.00% 2 100.00%



static inline void native_write_cr3(unsigned long val)
{
	asm volatile("mov %0,%%cr3": : "r" (val), "m" (__force_order));
}

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David Howells 14 100.00% 1 100.00%
Total 14 100.00% 1 100.00%



static inline unsigned long native_read_cr4(void)
{
	unsigned long val;
#ifdef CONFIG_X86_32
	/*
         * This could fault if CR4 does not exist.  Non-existent CR4
         * is functionally equivalent to CR4 == 0.  Keep it simple and pretend
         * that CR4 == 0 on CPUs that don't have CR4.
         */
	asm volatile("1: mov %%cr4, %0\n"
                     "2:\n"
                     _ASM_EXTABLE(1b, 2b)
                     : "=r" (val), "=m" (__force_order) : "0" (0));
#else
	/* CR4 always exists on x86_64. */
	asm volatile("mov %%cr4,%0\n\t" : "=r" (val), "=m" (__force_order));
#endif
	return val;
}

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David Howells 27 84.38% 1 50.00%
Andrew Lutomirski 5 15.62% 1 50.00%
Total 32 100.00% 2 100.00%



static inline void native_write_cr4(unsigned long val)
{
	asm volatile("mov %0,%%cr4": : "r" (val), "m" (__force_order));
}

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David Howells 14 100.00% 1 100.00%
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#ifdef CONFIG_X86_64


static inline unsigned long native_read_cr8(void)
{
	unsigned long cr8;
	asm volatile("movq %%cr8,%0" : "=r" (cr8));
	return cr8;
}

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static inline void native_write_cr8(unsigned long val)
{
	asm volatile("movq %0,%%cr8" :: "r" (val) : "memory");
}
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#endif

#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS


static inline u32 __read_pkru(void)
{
	u32 ecx = 0;
	u32 edx, pkru;

	/*
         * "rdpkru" instruction.  Places PKRU contents in to EAX,
         * clears EDX and requires that ecx=0.
         */
	asm volatile(".byte 0x0f,0x01,0xee\n\t"
                     : "=a" (pkru), "=d" (edx)
                     : "c" (ecx));
	return pkru;
}

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Dave Hansen 26 100.00% 1 100.00%
Total 26 100.00% 1 100.00%



static inline void __write_pkru(u32 pkru)
{
	u32 ecx = 0, edx = 0;

	/*
         * "wrpkru" instruction.  Loads contents in EAX to PKRU,
         * requires that ecx = edx = 0.
         */
	asm volatile(".byte 0x0f,0x01,0xef\n\t"
                     : : "a" (pkru), "c"(ecx), "d"(edx));
}
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Xiao Guangrong 23 100.00% 1 100.00%
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#else


static inline u32 __read_pkru(void)
{
	return 0;
}

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Dave Hansen 12 100.00% 1 100.00%
Total 12 100.00% 1 100.00%



static inline void __write_pkru(u32 pkru)
{
}
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Xiao Guangrong 9 100.00% 1 100.00%
Total 9 100.00% 1 100.00%

#endif



static inline void native_wbinvd(void)
{
	asm volatile("wbinvd": : :"memory");
}

Contributors
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David Howells 12 100.00% 1 100.00%
Total 12 100.00% 1 100.00%

extern asmlinkage void native_load_gs_index(unsigned);



static inline unsigned long __read_cr4(void)
{
	return native_read_cr4();
}

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Juergen Gross 14 100.00% 1 100.00%
Total 14 100.00% 1 100.00%

#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#else



static inline unsigned long read_cr0(void)
{
	return native_read_cr0();
}

Contributors
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David Howells 14 100.00% 1 100.00%
Total 14 100.00% 1 100.00%



static inline void write_cr0(unsigned long x)
{
	native_write_cr0(x);
}

Contributors
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David Howells 16 100.00% 1 100.00%
Total 16 100.00% 1 100.00%



static inline unsigned long read_cr2(void)
{
	return native_read_cr2();
}

Contributors
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David Howells 14 100.00% 1 100.00%
Total 14 100.00% 1 100.00%



static inline void write_cr2(unsigned long x)
{
	native_write_cr2(x);
}

Contributors
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David Howells 16 100.00% 1 100.00%
Total 16 100.00% 1 100.00%

/*
 * Careful!  CR3 contains more than just an address.  You probably want
 * read_cr3_pa() instead.
 */


static inline unsigned long __read_cr3(void)
{
	return __native_read_cr3();
}

Contributors
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David Howells 12 85.71% 1 50.00%
Andrew Lutomirski 2 14.29% 1 50.00%
Total 14 100.00% 2 100.00%



static inline void write_cr3(unsigned long x)
{
	native_write_cr3(x);
}

Contributors
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David Howells 16 100.00% 1 100.00%
Total 16 100.00% 1 100.00%



static inline void __write_cr4(unsigned long x)
{
	native_write_cr4(x);
}

Contributors
Person Tokens Prop Commits CommitProp
David Howells 15 93.75% 1 50.00%
Andrew Lutomirski 1 6.25% 1 50.00%
Total 16 100.00% 2 100.00%



static inline void wbinvd(void)
{
	native_wbinvd();
}

Contributors
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David Howells 12 100.00% 1 100.00%
Total 12 100.00% 1 100.00%

#ifdef CONFIG_X86_64



static inline unsigned long read_cr8(void)
{
	return native_read_cr8();
}

Contributors
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David Howells 14 100.00% 1 100.00%
Total 14 100.00% 1 100.00%



static inline void write_cr8(unsigned long x)
{
	native_write_cr8(x);
}

Contributors
Person Tokens Prop Commits CommitProp
David Howells 16 100.00% 1 100.00%
Total 16 100.00% 1 100.00%



static inline void load_gs_index(unsigned selector)
{
	native_load_gs_index(selector);
}

Contributors
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David Howells 15 100.00% 1 100.00%
Total 15 100.00% 1 100.00%

#endif

#endif/* CONFIG_PARAVIRT */



static inline void clflush(volatile void *__p)
{
	asm volatile("clflush %0" : "+m" (*(volatile char __force *)__p));
}

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David Howells 15 100.00% 1 100.00%
Total 15 100.00% 1 100.00%



static inline void clflushopt(volatile void *__p)
{
	alternative_io(".byte " __stringify(NOP_DS_PREFIX) "; clflush %P0",
		       ".byte 0x66; clflush %P0",
		       X86_FEATURE_CLFLUSHOPT,
		       "+m" (*(volatile char __force *)__p));
}

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Ross Zwisler 38 100.00% 1 100.00%
Total 38 100.00% 1 100.00%



static inline void clwb(volatile void *__p)
{
	volatile struct { char x[64]; } *p = __p;

	asm volatile(ALTERNATIVE_2(
                ".byte " __stringify(NOP_DS_PREFIX) "; clflush (%[pax])",
                ".byte 0x66; clflush (%[pax])", /* clflushopt (%%rax) */
		X86_FEATURE_CLFLUSHOPT,
                ".byte 0x66, 0x0f, 0xae, 0x30",  /* clwb (%%rax) */
		X86_FEATURE_CLWB)
                : [p] "+m" (*p)
                : [pax] "a" (p));
}

Contributors
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Ross Zwisler 34 100.00% 1 100.00%
Total 34 100.00% 1 100.00%


#define nop() asm volatile ("nop")


#endif /* __KERNEL__ */

#endif /* _ASM_X86_SPECIAL_INSNS_H */
Overall Contributors
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David Howells 416 69.92% 1 7.69%
Ross Zwisler 75 12.61% 3 23.08%
Dave Hansen 45 7.56% 1 7.69%
Xiao Guangrong 32 5.38% 1 7.69%
Juergen Gross 14 2.35% 1 7.69%
Andrew Lutomirski 10 1.68% 3 23.08%
Jan Beulich 1 0.17% 1 7.69%
Greg Kroah-Hartman 1 0.17% 1 7.69%
Andi Kleen 1 0.17% 1 7.69%
Total 595 100.00% 13 100.00%
Directory: arch/x86/include/asm

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Person	Tokens	Prop	Commits	CommitProp
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Total	20	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.14 arch/x86/include/asm/special_insns.h

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