s390/kernel: remove save_fpu_regs() parameter and use __LC_CURRENT instead

All calls to save_fpu_regs() specify the fpu structure of the current task
pointer as parameter.  The task pointer of the current task can also be
retrieved from the CPU lowcore directly.  Remove the parameter definition,
load the __LC_CURRENT task pointer from the CPU lowcore, and rebase the FPU
structure onto the task structure.  Apply the same approach for the
load_fpu_regs() function.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/fpu-internal.h b/arch/s390/include/asm/fpu-internal.h
index 237f8fcbe46b410dc66bb71a5ae86c0d8ff896af..55dc2c0fb40a76b00861b2353261cd5c1795b645 100644 (file)
--- a/arch/s390/include/asm/fpu-internal.h
+++ b/arch/s390/include/asm/fpu-internal.h
@@ -28,7 +28,7 @@ struct fpu {
        };
 };
 
-void save_fpu_regs(struct fpu *fpu);
+void save_fpu_regs(void);
 
 #define is_vx_fpu(fpu) (!!((fpu)->flags & FPU_USE_VX))
 #define is_vx_task(tsk) (!!((tsk)->thread.fpu.flags & FPU_USE_VX))

diff --git a/arch/s390/include/asm/switch_to.h b/arch/s390/include/asm/switch_to.h
index 0a4a3150b7d76401d977eccbc56545a2067028d4..dcadfde32265ad705a3899ef1584f858ae3af704 100644 (file)
--- a/arch/s390/include/asm/switch_to.h
+++ b/arch/s390/include/asm/switch_to.h
@@ -30,7 +30,7 @@ static inline void restore_access_regs(unsigned int *acrs)
 
 #define switch_to(prev,next,last) do {                                 \
        if (prev->mm) {                                                 \
-               save_fpu_regs(&prev->thread.fpu);                       \
+               save_fpu_regs();                                        \
                save_access_regs(&prev->thread.acrs[0]);                \
                save_ri_cb(prev->thread.ri_cb);                         \
        }                                                               \

diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 6bc42c08be09d13ea188402df4227907ec822ed1..48c9af7a76831ea63ef6ef92760df02f15c1188c 100644 (file)
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -28,16 +28,14 @@ int main(void)
        DEFINE(__TASK_pid, offsetof(struct task_struct, pid));
        BLANK();
        DEFINE(__THREAD_ksp, offsetof(struct thread_struct, ksp));
-       DEFINE(__THREAD_fpu, offsetof(struct task_struct, thread.fpu));
+       DEFINE(__THREAD_FPU_fpc, offsetof(struct thread_struct, fpu.fpc));
+       DEFINE(__THREAD_FPU_flags, offsetof(struct thread_struct, fpu.flags));
+       DEFINE(__THREAD_FPU_regs, offsetof(struct thread_struct, fpu.regs));
        DEFINE(__THREAD_per_cause, offsetof(struct thread_struct, per_event.cause));
        DEFINE(__THREAD_per_address, offsetof(struct thread_struct, per_event.address));
        DEFINE(__THREAD_per_paid, offsetof(struct thread_struct, per_event.paid));
        DEFINE(__THREAD_trap_tdb, offsetof(struct thread_struct, trap_tdb));
        BLANK();
-       DEFINE(__FPU_fpc, offsetof(struct fpu, fpc));
-       DEFINE(__FPU_flags, offsetof(struct fpu, flags));
-       DEFINE(__FPU_regs, offsetof(struct fpu, regs));
-       BLANK();
        DEFINE(__TI_task, offsetof(struct thread_info, task));
        DEFINE(__TI_flags, offsetof(struct thread_info, flags));
        DEFINE(__TI_sysc_table, offsetof(struct thread_info, sys_call_table));

diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c
index 0b46fd4aa31e4ae9e152be6f9a12c842808aeae6..eb4664238613a0c7db83e7910ae065a9b584e95b 100644 (file)
--- a/arch/s390/kernel/compat_signal.c
+++ b/arch/s390/kernel/compat_signal.c
@@ -154,7 +154,7 @@ int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
 static void store_sigregs(void)
 {
        save_access_regs(current->thread.acrs);
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
 }
 
 /* Load registers after signal return */
@@ -286,7 +286,7 @@ COMPAT_SYSCALL_DEFINE0(sigreturn)
        if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE32))
                goto badframe;
        set_current_blocked(&set);
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
        if (restore_sigregs32(regs, &frame->sregs))
                goto badframe;
        if (restore_sigregs_ext32(regs, &frame->sregs_ext))
@@ -309,7 +309,7 @@ COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
        set_current_blocked(&set);
        if (compat_restore_altstack(&frame->uc.uc_stack))
                goto badframe;
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
        if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
                goto badframe;
        if (restore_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext))

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 21c1219122afe865d2564dd7bf293c857b2220ee..5a966dea937fb15e2bab269394865abcf78df13e 100644 (file)
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -183,7 +183,6 @@ ENTRY(sie64a)
        xc      __SF_EMPTY+16(16,%r15),__SF_EMPTY+16(%r15) # host id & reason
        tm      __LC_CPU_FLAGS+7,_CIF_FPU       # load guest fp/vx registers ?
        jno     .Lsie_load_guest_gprs
-       lg      %r12,__LC_THREAD_INFO           # load fp/vx regs save area
        brasl   %r14,load_fpu_regs              # load guest fp/vx regs
 .Lsie_load_guest_gprs:
        lmg     %r0,%r13,0(%r3)                 # load guest gprs 0-13
@@ -752,14 +751,16 @@ ENTRY(psw_idle)
  * of the register contents at system call or io return.
  */
 ENTRY(save_fpu_regs)
+       lg      %r2,__LC_CURRENT
+       aghi    %r2,__TASK_thread
        tm      __LC_CPU_FLAGS+7,_CIF_FPU
        bor     %r14
-       stfpc   __FPU_fpc(%r2)
+       stfpc   __THREAD_FPU_fpc(%r2)
 .Lsave_fpu_regs_fpc_end:
-       lg      %r3,__FPU_regs(%r2)
+       lg      %r3,__THREAD_FPU_regs(%r2)
        ltgr    %r3,%r3
        jz      .Lsave_fpu_regs_done      # no save area -> set CIF_FPU
-       tm      __FPU_flags+3(%r2),FPU_USE_VX
+       tm      __THREAD_FPU_flags+3(%r2),FPU_USE_VX
        jz      .Lsave_fpu_regs_fp        # no -> store FP regs
 .Lsave_fpu_regs_vx_low:
        VSTM    %v0,%v15,0,%r3            # vstm 0,15,0(3)
@@ -794,20 +795,19 @@ ENTRY(save_fpu_regs)
  * FP/VX state, the vector-enablement control, CR0.46, is either set or cleared.
  *
  * There are special calling conventions to fit into sysc and io return work:
- *     %r12:   __LC_THREAD_INFO
  *     %r15:   <kernel stack>
  * The function requires:
  *     %r4 and __SF_EMPTY+32(%r15)
  */
 load_fpu_regs:
+       lg      %r4,__LC_CURRENT
+       aghi    %r4,__TASK_thread
        tm      __LC_CPU_FLAGS+7,_CIF_FPU
        bnor    %r14
-       lg      %r4,__TI_task(%r12)
-       la      %r4,__THREAD_fpu(%r4)
-       lfpc    __FPU_fpc(%r4)
+       lfpc    __THREAD_FPU_fpc(%r4)
        stctg   %c0,%c0,__SF_EMPTY+32(%r15)     # store CR0
-       tm      __FPU_flags+3(%r4),FPU_USE_VX   # VX-enabled task ?
-       lg      %r4,__FPU_regs(%r4)             # %r4 <- reg save area
+       tm      __THREAD_FPU_flags+3(%r4),FPU_USE_VX    # VX-enabled task ?
+       lg      %r4,__THREAD_FPU_regs(%r4)      # %r4 <- reg save area
        jz      .Lload_fpu_regs_fp_ctl          # -> no VX, load FP regs
 .Lload_fpu_regs_vx_ctl:
        tm      __SF_EMPTY+32+5(%r15),2         # test VX control
@@ -1190,13 +1190,14 @@ cleanup_critical:
        jhe     2f
        clg     %r9,BASED(.Lcleanup_save_fpu_fpc_end)
        jhe     1f
+       lg      %r2,__LC_CURRENT
 0:     # Store floating-point controls
-       stfpc   __FPU_fpc(%r2)
+       stfpc   __THREAD_FPU_fpc(%r2)
 1:     # Load register save area and check if VX is active
-       lg      %r3,__FPU_regs(%r2)
+       lg      %r3,__THREAD_FPU_regs(%r2)
        ltgr    %r3,%r3
        jz      5f                        # no save area -> set CIF_FPU
-       tm      __FPU_flags+3(%r2),FPU_USE_VX
+       tm      __THREAD_FPU_flags+3(%r2),FPU_USE_VX
        jz      4f                        # no VX -> store FP regs
 2:     # Store vector registers (V0-V15)
        VSTM    %v0,%v15,0,%r3            # vstm 0,15,0(3)
@@ -1250,11 +1251,10 @@ cleanup_critical:
        jhe     5f
        clg     %r9,BASED(.Lcleanup_load_fpu_regs_vx_ctl)
        jhe     6f
-       lg      %r4,__TI_task(%r12)
-       la      %r4,__THREAD_fpu(%r4)
-       lfpc    __FPU_fpc(%r4)
-       tm      __FPU_flags+3(%r4),FPU_USE_VX   # VX-enabled task ?
-       lg      %r4,__FPU_regs(%r4)             # %r4 <- reg save area
+       lg      %r4,__LC_CURRENT
+       lfpc    __THREAD_FPU_fpc(%r4)
+       tm      __THREAD_FPU_flags+3(%r4),FPU_USE_VX    # VX-enabled task ?
+       lg      %r4,__THREAD_FPU_regs(%r4)      # %r4 <- reg save area
        jz      3f                              # -> no VX, load FP regs
 6:     # Set VX-enablement control
        stctg   %c0,%c0,__SF_EMPTY+32(%r15)     # store CR0

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 9cf0063f920e68a8ed6974e0e1487bc630876349..f2dac9f0799dc04a5bb07c4529bf617e84e82d0c 100644 (file)
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -104,7 +104,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
         * The CIF_FPU flag is set in any case to lazy clear or restore a saved
         * state when switching to a different task or returning to user space.
         */
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
        dst->thread.fpu.fpc = current->thread.fpu.fpc;
        if (is_vx_task(current))
                convert_vx_to_fp(dst->thread.fpu.fprs,
@@ -196,7 +196,7 @@ asmlinkage void execve_tail(void)
  */
 int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
 {
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
        fpregs->fpc = current->thread.fpu.fpc;
        fpregs->pad = 0;
        if (is_vx_task(current))

diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 8c525880a3ff7ddb1e406bd7b257503e81ff8f81..8b1c8e33f184a94f057d35f479145734aafc6ad0 100644 (file)
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -943,7 +943,7 @@ static int s390_fpregs_get(struct task_struct *target,
        _s390_fp_regs fp_regs;
 
        if (target == current)
-               save_fpu_regs(&target->thread.fpu);
+               save_fpu_regs();
 
        fp_regs.fpc = target->thread.fpu.fpc;
        fpregs_store(&fp_regs, &target->thread.fpu);
@@ -961,7 +961,7 @@ static int s390_fpregs_set(struct task_struct *target,
        freg_t fprs[__NUM_FPRS];
 
        if (target == current)
-               save_fpu_regs(&target->thread.fpu);
+               save_fpu_regs();
 
        /* If setting FPC, must validate it first. */
        if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
@@ -1049,7 +1049,7 @@ static int s390_vxrs_low_get(struct task_struct *target,
                return -ENODEV;
        if (is_vx_task(target)) {
                if (target == current)
-                       save_fpu_regs(&target->thread.fpu);
+                       save_fpu_regs();
                for (i = 0; i < __NUM_VXRS_LOW; i++)
                        vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
        } else
@@ -1072,7 +1072,7 @@ static int s390_vxrs_low_set(struct task_struct *target,
                if (rc)
                        return rc;
        } else if (target == current)
-               save_fpu_regs(&target->thread.fpu);
+               save_fpu_regs();
 
        rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
        if (rc == 0)
@@ -1093,7 +1093,7 @@ static int s390_vxrs_high_get(struct task_struct *target,
                return -ENODEV;
        if (is_vx_task(target)) {
                if (target == current)
-                       save_fpu_regs(&target->thread.fpu);
+                       save_fpu_regs();
                memcpy(vxrs, target->thread.fpu.vxrs + __NUM_VXRS_LOW,
                       sizeof(vxrs));
        } else
@@ -1115,7 +1115,7 @@ static int s390_vxrs_high_set(struct task_struct *target,
                if (rc)
                        return rc;
        } else if (target == current)
-               save_fpu_regs(&target->thread.fpu);
+               save_fpu_regs();
 
        rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);

diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index 2f4c7e2638c916bef2ab0e20d016133ded183da1..9549af102d75aaa02e02b7bcbb02de06341bc5f8 100644 (file)
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -105,7 +105,7 @@ struct rt_sigframe
 static void store_sigregs(void)
 {
        save_access_regs(current->thread.acrs);
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
 }
 
 /* Load registers after signal return */
@@ -222,7 +222,7 @@ SYSCALL_DEFINE0(sigreturn)
        if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
                goto badframe;
        set_current_blocked(&set);
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
        if (restore_sigregs(regs, &frame->sregs))
                goto badframe;
        if (restore_sigregs_ext(regs, &frame->sregs_ext))
@@ -246,7 +246,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
        set_current_blocked(&set);
        if (restore_altstack(&frame->uc.uc_stack))
                goto badframe;
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
        if (restore_sigregs(regs, &frame->uc.uc_mcontext))
                goto badframe;
        if (restore_sigregs_ext(regs, &frame->uc.uc_mcontext_ext))

diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index 76f76932ccb9f6d35901ff69380af3a4f12b7668..9861613fb35a7a0c1ef947451f37871937d9c5bd 100644 (file)
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -236,7 +236,7 @@ int alloc_vector_registers(struct task_struct *tsk)
                return -ENOMEM;
        preempt_disable();
        if (tsk == current)
-               save_fpu_regs(&tsk->thread.fpu);
+               save_fpu_regs();
        /* Copy the 16 floating point registers */
        convert_fp_to_vx(vxrs, tsk->thread.fpu.fprs);
        fprs = tsk->thread.fpu.fprs;
@@ -257,7 +257,7 @@ void vector_exception(struct pt_regs *regs)
        }
 
        /* get vector interrupt code from fpc */
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
        vic = (current->thread.fpu.fpc & 0xf00) >> 8;
        switch (vic) {
        case 1: /* invalid vector operation */
@@ -295,7 +295,7 @@ void data_exception(struct pt_regs *regs)
 
        location = get_trap_ip(regs);
 
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
        /* Check for vector register enablement */
        if (MACHINE_HAS_VX && !is_vx_task(current) &&
            (current->thread.fpu.fpc & FPC_DXC_MASK) == 0xfe00) {

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index c0cceaf4a92ead14ccf5f69c9e34d777895b68b3..1903f0212bd06316ca527381b22003360f59c388 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1224,7 +1224,7 @@ static inline void load_fpu_from(struct fpu *from)
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
        /* Save host register state */
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
        save_fpu_to(&vcpu->arch.host_fpregs);
 
        if (test_kvm_facility(vcpu->kvm, 129)) {
@@ -1256,7 +1256,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
        atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
        gmap_disable(vcpu->arch.gmap);
 
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
 
        if (test_kvm_facility(vcpu->kvm, 129))
                /*
@@ -1671,7 +1671,7 @@ int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
                return -EINVAL;
        memcpy(vcpu->arch.guest_fpregs.fprs, &fpu->fprs, sizeof(fpu->fprs));
        vcpu->arch.guest_fpregs.fpc = fpu->fpc;
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
        load_fpu_from(&vcpu->arch.guest_fpregs);
        return 0;
 }
@@ -2241,7 +2241,7 @@ int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr)
         * copying in vcpu load/put. Lets update our copies before we save
         * it into the save area
         */
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
        if (test_kvm_facility(vcpu->kvm, 129)) {
                /*
                 * If the vector extension is available, the vector registers
@@ -2288,7 +2288,7 @@ int kvm_s390_vcpu_store_adtl_status(struct kvm_vcpu *vcpu, unsigned long addr)
         *
         * Let's update our copies before we save it into the save area.
         */
-       save_fpu_regs(&current->thread.fpu);
+       save_fpu_regs();
 
        return kvm_s390_store_adtl_status_unloaded(vcpu, addr);
 }