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    Subject[PATCH 060/208] x86/fpu: Use 'struct fpu' in switch_fpu_prepare()
    Date
    Migrate this function to pure 'struct fpu' usage.

    Reviewed-by: Borislav Petkov <bp@alien8.de>
    Cc: Andy Lutomirski <luto@amacapital.net>
    Cc: Dave Hansen <dave.hansen@linux.intel.com>
    Cc: Fenghua Yu <fenghua.yu@intel.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Oleg Nesterov <oleg@redhat.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Signed-off-by: Ingo Molnar <mingo@kernel.org>
    ---
    arch/x86/include/asm/fpu-internal.h | 27 +++++++++++++--------------
    arch/x86/kernel/process_32.c | 2 +-
    arch/x86/kernel/process_64.c | 2 +-
    3 files changed, 15 insertions(+), 16 deletions(-)

    diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
    index 579f7d0a399d..60d2c6f376f3 100644
    --- a/arch/x86/include/asm/fpu-internal.h
    +++ b/arch/x86/include/asm/fpu-internal.h
    @@ -402,10 +402,9 @@ static inline void fpu_reset_state(struct fpu *fpu)
    */
    typedef struct { int preload; } fpu_switch_t;

    -static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct task_struct *new, int cpu)
    +static inline fpu_switch_t
    +switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu)
    {
    - struct fpu *old_fpu = &old->thread.fpu;
    - struct fpu *new_fpu = &new->thread.fpu;
    fpu_switch_t fpu;

    /*
    @@ -413,33 +412,33 @@ static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct ta
    * or if the past 5 consecutive context-switches used math.
    */
    fpu.preload = new_fpu->fpstate_active &&
    - (use_eager_fpu() || new->thread.fpu.counter > 5);
    + (use_eager_fpu() || new_fpu->counter > 5);

    if (old_fpu->has_fpu) {
    - if (!fpu_save_init(&old->thread.fpu))
    - old->thread.fpu.last_cpu = -1;
    + if (!fpu_save_init(old_fpu))
    + old_fpu->last_cpu = -1;
    else
    - old->thread.fpu.last_cpu = cpu;
    + old_fpu->last_cpu = cpu;

    /* But leave fpu_fpregs_owner_ctx! */
    - old->thread.fpu.has_fpu = 0;
    + old_fpu->has_fpu = 0;

    /* Don't change CR0.TS if we just switch! */
    if (fpu.preload) {
    - new->thread.fpu.counter++;
    + new_fpu->counter++;
    __thread_set_has_fpu(new_fpu);
    - prefetch(new->thread.fpu.state);
    + prefetch(new_fpu->state);
    } else if (!use_eager_fpu())
    stts();
    } else {
    - old->thread.fpu.counter = 0;
    - old->thread.fpu.last_cpu = -1;
    + old_fpu->counter = 0;
    + old_fpu->last_cpu = -1;
    if (fpu.preload) {
    - new->thread.fpu.counter++;
    + new_fpu->counter++;
    if (fpu_want_lazy_restore(new_fpu, cpu))
    fpu.preload = 0;
    else
    - prefetch(new->thread.fpu.state);
    + prefetch(new_fpu->state);
    __thread_fpu_begin(new_fpu);
    }
    }
    diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
    index 1a0edce626b2..5b0ed71dde60 100644
    --- a/arch/x86/kernel/process_32.c
    +++ b/arch/x86/kernel/process_32.c
    @@ -248,7 +248,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)

    /* never put a printk in __switch_to... printk() calls wake_up*() indirectly */

    - fpu = switch_fpu_prepare(prev_p, next_p, cpu);
    + fpu = switch_fpu_prepare(&prev_p->thread.fpu, &next_p->thread.fpu, cpu);

    /*
    * Save away %gs. No need to save %fs, as it was saved on the
    diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
    index 99cc4b8589ad..fefe65efd9d6 100644
    --- a/arch/x86/kernel/process_64.c
    +++ b/arch/x86/kernel/process_64.c
    @@ -278,7 +278,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
    unsigned fsindex, gsindex;
    fpu_switch_t fpu;

    - fpu = switch_fpu_prepare(prev_p, next_p, cpu);
    + fpu = switch_fpu_prepare(&prev_p->thread.fpu, &next_p->thread.fpu, cpu);

    /* We must save %fs and %gs before load_TLS() because
    * %fs and %gs may be cleared by load_TLS().
    --
    2.1.0


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