root/include/asm-x86/xsave.h

INCLUDED FROM

DEFINITIONS

1. xrstor_checking
2. xsave_user
3. xrestore_user
4. xrstor_state
5. xsave

#ifndef __ASM_X86_XSAVE_H
#define __ASM_X86_XSAVE_H

#include <linux/types.h>
#include <asm/processor.h>
#include <asm/i387.h>

#define XSTATE_FP       0x1
#define XSTATE_SSE      0x2

#define XSTATE_FPSSE    (XSTATE_FP | XSTATE_SSE)

#define FXSAVE_SIZE     512

/*
 * These are the features that the OS can handle currently.
 */
#define XCNTXT_MASK     (XSTATE_FP | XSTATE_SSE)

#ifdef CONFIG_X86_64
#define REX_PREFIX      "0x48, "
#else
#define REX_PREFIX
#endif

extern unsigned int xstate_size;
extern u64 pcntxt_mask;
extern struct xsave_struct *init_xstate_buf;

extern void xsave_cntxt_init(void);
extern void xsave_init(void);
extern int init_fpu(struct task_struct *child);
extern int check_for_xstate(struct i387_fxsave_struct __user *buf,
                            void __user *fpstate,
                            struct _fpx_sw_bytes *sw);

static inline int xrstor_checking(struct xsave_struct *fx)
{
        int err;

        asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
                     "2:\n"
                     ".section .fixup,\"ax\"\n"
                     "3:  movl $-1,%[err]\n"
                     "    jmp  2b\n"
                     ".previous\n"
                     _ASM_EXTABLE(1b, 3b)
                     : [err] "=r" (err)
                     : "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
                     : "memory");

        return err;
}

static inline int xsave_user(struct xsave_struct __user *buf)
{
        int err;
        __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
                             "2:\n"
                             ".section .fixup,\"ax\"\n"
                             "3:  movl $-1,%[err]\n"
                             "    jmp  2b\n"
                             ".previous\n"
                             ".section __ex_table,\"a\"\n"
                             _ASM_ALIGN "\n"
                             _ASM_PTR "1b,3b\n"
                             ".previous"
                             : [err] "=r" (err)
                             : "D" (buf), "a" (-1), "d" (-1), "0" (0)
                             : "memory");
        if (unlikely(err) && __clear_user(buf, xstate_size))
                err = -EFAULT;
        /* No need to clear here because the caller clears USED_MATH */
        return err;
}

static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
{
        int err;
        struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
        u32 lmask = mask;
        u32 hmask = mask >> 32;

        __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
                             "2:\n"
                             ".section .fixup,\"ax\"\n"
                             "3:  movl $-1,%[err]\n"
                             "    jmp  2b\n"
                             ".previous\n"
                             ".section __ex_table,\"a\"\n"
                             _ASM_ALIGN "\n"
                             _ASM_PTR "1b,3b\n"
                             ".previous"
                             : [err] "=r" (err)
                             : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
                             : "memory");       /* memory required? */
        return err;
}

static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
{
        u32 lmask = mask;
        u32 hmask = mask >> 32;

        asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
                     : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
                     :   "memory");
}

static inline void xsave(struct task_struct *tsk)
{
        /* This, however, we can work around by forcing the compiler to select
           an addressing mode that doesn't require extended registers. */
        __asm__ __volatile__(".byte " REX_PREFIX "0x0f,0xae,0x27"
                             : : "D" (&(tsk->thread.xstate->xsave)),
                                 "a" (-1), "d"(-1) : "memory");
}
#endif