switch_to.h

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/*
 * Copyright IBM Corp. 1999, 2009
 *
 * Author(s): Martin Schwidefsky <[email protected]>
 */

#ifndef __ASM_SWITCH_TO_H
#define __ASM_SWITCH_TO_H

#include <linux/thread_info.h>

extern struct task_struct *__switch_to(void *, void *);
extern void update_per_regs(struct task_struct *task);

static inline void save_fp_regs(s390_fp_regs *fpregs)
{
    asm volatile(
        "   std 0,%O0+8(%R0)\n"
        "   std 2,%O0+24(%R0)\n"
        "   std 4,%O0+40(%R0)\n"
        "   std 6,%O0+56(%R0)"
        : "=Q" (*fpregs) : "Q" (*fpregs));
    if (!MACHINE_HAS_IEEE)
        return;
    asm volatile(
        "   stfpc   %0\n"
        "   std 1,%O0+16(%R0)\n"
        "   std 3,%O0+32(%R0)\n"
        "   std 5,%O0+48(%R0)\n"
        "   std 7,%O0+64(%R0)\n"
        "   std 8,%O0+72(%R0)\n"
        "   std 9,%O0+80(%R0)\n"
        "   std 10,%O0+88(%R0)\n"
        "   std 11,%O0+96(%R0)\n"
        "   std 12,%O0+104(%R0)\n"
        "   std 13,%O0+112(%R0)\n"
        "   std 14,%O0+120(%R0)\n"
        "   std 15,%O0+128(%R0)\n"
        : "=Q" (*fpregs) : "Q" (*fpregs));
}

static inline void restore_fp_regs(s390_fp_regs *fpregs)
{
    asm volatile(
        "   ld  0,%O0+8(%R0)\n"
        "   ld  2,%O0+24(%R0)\n"
        "   ld  4,%O0+40(%R0)\n"
        "   ld  6,%O0+56(%R0)"
        : : "Q" (*fpregs));
    if (!MACHINE_HAS_IEEE)
        return;
    asm volatile(
        "   lfpc    %0\n"
        "   ld  1,%O0+16(%R0)\n"
        "   ld  3,%O0+32(%R0)\n"
        "   ld  5,%O0+48(%R0)\n"
        "   ld  7,%O0+64(%R0)\n"
        "   ld  8,%O0+72(%R0)\n"
        "   ld  9,%O0+80(%R0)\n"
        "   ld  10,%O0+88(%R0)\n"
        "   ld  11,%O0+96(%R0)\n"
        "   ld  12,%O0+104(%R0)\n"
        "   ld  13,%O0+112(%R0)\n"
        "   ld  14,%O0+120(%R0)\n"
        "   ld  15,%O0+128(%R0)\n"
        : : "Q" (*fpregs));
}

static inline void save_access_regs(unsigned int *acrs)
{
    asm volatile("stam 0,15,%0" : "=Q" (*acrs));
}

static inline void restore_access_regs(unsigned int *acrs)
{
    asm volatile("lam 0,15,%0" : : "Q" (*acrs));
}

#define switch_to(prev,next,last) do {                  \
    if (prev->mm) {                         \
        save_fp_regs(&prev->thread.fp_regs);            \
        save_access_regs(&prev->thread.acrs[0]);        \
        save_ri_cb(prev->thread.ri_cb);             \
    }                               \
    if (next->mm) {                         \
        restore_fp_regs(&next->thread.fp_regs);         \
        restore_access_regs(&next->thread.acrs[0]);     \
        restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb);  \
        update_per_regs(next);                  \
    }                               \
    prev = __switch_to(prev,next);                  \
} while (0)

#define finish_arch_switch(prev) do {                        \
    set_fs(current->thread.mm_segment);                  \
} while (0)

#endif /* __ASM_SWITCH_TO_H */