x86: Introduce 'struct fpu' and related API

Currently all fpu state access is through tsk->thread.xstate.  Since we wish
to generalize fpu access to non-task contexts, wrap the state in a new
'struct fpu' and convert existing access to use an fpu API.

Signal frame handlers are not converted to the API since they will remain
task context only things.

Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1273135546-29690-3-git-send-email-avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 51 insertions, 51 deletions

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 14ca1dc7a703..86cef6b32253 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -107,57 +107,57 @@ void __cpuinit fpu_init(void)
 }
 #endif  /* CONFIG_X86_64 */
 
-/*
- * The _current_ task is using the FPU for the first time
- * so initialize it and set the mxcsr to its default
- * value at reset if we support XMM instructions and then
- * remeber the current task has used the FPU.
- */
-int init_fpu(struct task_struct *tsk)
+static void fpu_finit(struct fpu *fpu)
 {
-        if (tsk_used_math(tsk)) {
-                if (HAVE_HWFP && tsk == current)
-                        unlazy_fpu(tsk);
-                return 0;
-        }
-
-        /*
-         * Memory allocation at the first usage of the FPU and other state.
-         */
-        if (!tsk->thread.xstate) {
-                tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
-                                                      GFP_KERNEL);
-                if (!tsk->thread.xstate)
-                        return -ENOMEM;
-        }
-
 #ifdef CONFIG_X86_32
         if (!HAVE_HWFP) {
-                memset(tsk->thread.xstate, 0, xstate_size);
-                finit_task(tsk);
-                set_stopped_child_used_math(tsk);
-                return 0;
+                finit_soft_fpu(&fpu->state->soft);
+                return;
         }
 #endif
 
         if (cpu_has_fxsr) {
-                struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
+                struct i387_fxsave_struct *fx = &fpu->state->fxsave;
 
                 memset(fx, 0, xstate_size);
                 fx->cwd = 0x37f;
                 if (cpu_has_xmm)
                         fx->mxcsr = MXCSR_DEFAULT;
         } else {
-                struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;
+                struct i387_fsave_struct *fp = &fpu->state->fsave;
                 memset(fp, 0, xstate_size);
                 fp->cwd = 0xffff037fu;
                 fp->swd = 0xffff0000u;
                 fp->twd = 0xffffffffu;
                 fp->fos = 0xffff0000u;
         }
+}
+
+/*
+ * The _current_ task is using the FPU for the first time
+ * so initialize it and set the mxcsr to its default
+ * value at reset if we support XMM instructions and then
+ * remeber the current task has used the FPU.
+ */
+int init_fpu(struct task_struct *tsk)
+{
+        int ret;
+
+        if (tsk_used_math(tsk)) {
+                if (HAVE_HWFP && tsk == current)
+                        unlazy_fpu(tsk);
+                return 0;
+        }
+
         /*
-         * Only the device not available exception or ptrace can call init_fpu.
+         * Memory allocation at the first usage of the FPU and other state.
          */
+        ret = fpu_alloc(&tsk->thread.fpu);
+        if (ret)
+                return ret;
+
+        fpu_finit(&tsk->thread.fpu);
+
         set_stopped_child_used_math(tsk);
         return 0;
 }
@@ -191,7 +191,7 @@ int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
                 return ret;
 
         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-                                   &target->thread.xstate->fxsave, 0, -1);
+                                   &target->thread.fpu.state->fxsave, 0, -1);
 }
 
 int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
@@ -208,19 +208,19 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
                 return ret;
 
         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
-                                 &target->thread.xstate->fxsave, 0, -1);
+                                 &target->thread.fpu.state->fxsave, 0, -1);
 
         /*
          * mxcsr reserved bits must be masked to zero for security reasons.
          */
-        target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
+        target->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask;
 
         /*
          * update the header bits in the xsave header, indicating the
          * presence of FP and SSE state.
          */
         if (cpu_has_xsave)
-                target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
+                target->thread.fpu.state->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
 
         return ret;
 }
@@ -243,14 +243,14 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset,
          * memory layout in the thread struct, so that we can copy the entire
          * xstateregs to the user using one user_regset_copyout().
          */
-        memcpy(&target->thread.xstate->fxsave.sw_reserved,
+        memcpy(&target->thread.fpu.state->fxsave.sw_reserved,
                xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes));
 
         /*
          * Copy the xstate memory layout.
          */
         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-                                  &target->thread.xstate->xsave, 0, -1);
+                                  &target->thread.fpu.state->xsave, 0, -1);
         return ret;
 }
 
@@ -269,14 +269,14 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
                 return ret;
 
         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
-                                 &target->thread.xstate->xsave, 0, -1);
+                                 &target->thread.fpu.state->xsave, 0, -1);
 
         /*
          * mxcsr reserved bits must be masked to zero for security reasons.
          */
-        target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
+        target->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask;
 
-        xsave_hdr = &target->thread.xstate->xsave.xsave_hdr;
+        xsave_hdr = &target->thread.fpu.state->xsave.xsave_hdr;
 
         xsave_hdr->xstate_bv &= pcntxt_mask;
         /*
@@ -362,7 +362,7 @@ static inline u32 twd_fxsr_to_i387(struct i387_fxsave_struct *fxsave)
 static void
 convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
 {
-        struct i387_fxsave_struct *fxsave = &tsk->thread.xstate->fxsave;
+        struct i387_fxsave_struct *fxsave = &tsk->thread.fpu.state->fxsave;
         struct _fpreg *to = (struct _fpreg *) &env->st_space[0];
         struct _fpxreg *from = (struct _fpxreg *) &fxsave->st_space[0];
         int i;
@@ -402,7 +402,7 @@ static void convert_to_fxsr(struct task_struct *tsk,
                             const struct user_i387_ia32_struct *env)
 
 {
-        struct i387_fxsave_struct *fxsave = &tsk->thread.xstate->fxsave;
+        struct i387_fxsave_struct *fxsave = &tsk->thread.fpu.state->fxsave;
         struct _fpreg *from = (struct _fpreg *) &env->st_space[0];
         struct _fpxreg *to = (struct _fpxreg *) &fxsave->st_space[0];
         int i;
@@ -442,7 +442,7 @@ int fpregs_get(struct task_struct *target, const struct user_regset *regset,
 
         if (!cpu_has_fxsr) {
                 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-                                           &target->thread.xstate->fsave, 0,
+                                           &target->thread.fpu.state->fsave, 0,
                                            -1);
         }
 
@@ -472,7 +472,7 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
 
         if (!cpu_has_fxsr) {
                 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
-                                          &target->thread.xstate->fsave, 0, -1);
+                                          &target->thread.fpu.state->fsave, 0, -1);
         }
 
         if (pos > 0 || count < sizeof(env))
@@ -487,7 +487,7 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
          * presence of FP.
          */
         if (cpu_has_xsave)
-                target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FP;
+                target->thread.fpu.state->xsave.xsave_hdr.xstate_bv |= XSTATE_FP;
         return ret;
 }
 
@@ -498,7 +498,7 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
 static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf)
 {
         struct task_struct *tsk = current;
-        struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;
+        struct i387_fsave_struct *fp = &tsk->thread.fpu.state->fsave;
 
         fp->status = fp->swd;
         if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct)))
@@ -509,7 +509,7 @@ static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf)
 static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
 {
         struct task_struct *tsk = current;
-        struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
+        struct i387_fxsave_struct *fx = &tsk->thread.fpu.state->fxsave;
         struct user_i387_ia32_struct env;
         int err = 0;
 
@@ -544,7 +544,7 @@ static int save_i387_xsave(void __user *buf)
          * header as well as change any contents in the memory layout.
          * xrestore as part of sigreturn will capture all the changes.
          */
-        tsk->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
+        tsk->thread.fpu.state->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
 
         if (save_i387_fxsave(fx) < 0)
                 return -1;
@@ -596,7 +596,7 @@ static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
 {
         struct task_struct *tsk = current;
 
-        return __copy_from_user(&tsk->thread.xstate->fsave, buf,
+        return __copy_from_user(&tsk->thread.fpu.state->fsave, buf,
                                 sizeof(struct i387_fsave_struct));
 }
 
@@ -607,10 +607,10 @@ static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf,
         struct user_i387_ia32_struct env;
         int err;
 
-        err = __copy_from_user(&tsk->thread.xstate->fxsave, &buf->_fxsr_env[0],
+        err = __copy_from_user(&tsk->thread.fpu.state->fxsave, &buf->_fxsr_env[0],
                                size);
         /* mxcsr reserved bits must be masked to zero for security reasons */
-        tsk->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
+        tsk->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask;
         if (err || __copy_from_user(&env, buf, sizeof(env)))
                 return 1;
         convert_to_fxsr(tsk, &env);
@@ -626,7 +626,7 @@ static int restore_i387_xsave(void __user *buf)
         struct i387_fxsave_struct __user *fx =
                 (struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0];
         struct xsave_hdr_struct *xsave_hdr =
-                                &current->thread.xstate->xsave.xsave_hdr;
+                                &current->thread.fpu.state->xsave.xsave_hdr;
         u64 mask;
         int err;