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>
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 14ca1dc..86cef6b 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -107,6 +107,32 @@
}
#endif /* CONFIG_X86_64 */
+static void fpu_finit(struct fpu *fpu)
+{
+#ifdef CONFIG_X86_32
+ if (!HAVE_HWFP) {
+ finit_soft_fpu(&fpu->state->soft);
+ return;
+ }
+#endif
+
+ if (cpu_has_fxsr) {
+ 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 = &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
@@ -115,6 +141,8 @@
*/
int init_fpu(struct task_struct *tsk)
{
+ int ret;
+
if (tsk_used_math(tsk)) {
if (HAVE_HWFP && tsk == current)
unlazy_fpu(tsk);
@@ -124,40 +152,12 @@
/*
* 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;
- }
+ ret = fpu_alloc(&tsk->thread.fpu);
+ if (ret)
+ return ret;
-#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;
- }
-#endif
+ fpu_finit(&tsk->thread.fpu);
- if (cpu_has_fxsr) {
- struct i387_fxsave_struct *fx = &tsk->thread.xstate->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;
- memset(fp, 0, xstate_size);
- fp->cwd = 0xffff037fu;
- fp->swd = 0xffff0000u;
- fp->twd = 0xffffffffu;
- fp->fos = 0xffff0000u;
- }
- /*
- * Only the device not available exception or ptrace can call init_fpu.
- */
set_stopped_child_used_math(tsk);
return 0;
}
@@ -191,7 +191,7 @@
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 @@
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 @@
* 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 @@
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 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 @@
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 @@
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 @@
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 @@
* 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 @@
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 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 @@
* 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 @@
{
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 @@
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 @@
struct i387_fxsave_struct __user *fx =
(struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0];
struct xsave_hdr_struct *xsave_hdr =
- ¤t->thread.xstate->xsave.xsave_hdr;
+ ¤t->thread.fpu.state->xsave.xsave_hdr;
u64 mask;
int err;
