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-rw-r--r--arch/x86/kernel/i387_64.c151
1 files changed, 151 insertions, 0 deletions
diff --git a/arch/x86/kernel/i387_64.c b/arch/x86/kernel/i387_64.c
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index 000000000000..1d58c13bc6bc
--- /dev/null
+++ b/arch/x86/kernel/i387_64.c
@@ -0,0 +1,151 @@
+/*
+ * linux/arch/x86_64/kernel/i387.c
+ *
+ * Copyright (C) 1994 Linus Torvalds
+ * Copyright (C) 2002 Andi Kleen, SuSE Labs
+ *
+ * Pentium III FXSR, SSE support
+ * General FPU state handling cleanups
+ * Gareth Hughes <gareth@valinux.com>, May 2000
+ *
+ * x86-64 rework 2002 Andi Kleen.
+ * Does direct fxsave in and out of user space now for signal handlers.
+ * All the FSAVE<->FXSAVE conversion code has been moved to the 32bit emulation,
+ * the 64bit user space sees a FXSAVE frame directly.
+ */
+
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <asm/processor.h>
+#include <asm/i387.h>
+#include <asm/sigcontext.h>
+#include <asm/user.h>
+#include <asm/ptrace.h>
+#include <asm/uaccess.h>
+
+unsigned int mxcsr_feature_mask __read_mostly = 0xffffffff;
+
+void mxcsr_feature_mask_init(void)
+{
+ unsigned int mask;
+ clts();
+ memset(&current->thread.i387.fxsave, 0, sizeof(struct i387_fxsave_struct));
+ asm volatile("fxsave %0" : : "m" (current->thread.i387.fxsave));
+ mask = current->thread.i387.fxsave.mxcsr_mask;
+ if (mask == 0) mask = 0x0000ffbf;
+ mxcsr_feature_mask &= mask;
+ stts();
+}
+
+/*
+ * Called at bootup to set up the initial FPU state that is later cloned
+ * into all processes.
+ */
+void __cpuinit fpu_init(void)
+{
+ unsigned long oldcr0 = read_cr0();
+ extern void __bad_fxsave_alignment(void);
+
+ if (offsetof(struct task_struct, thread.i387.fxsave) & 15)
+ __bad_fxsave_alignment();
+ set_in_cr4(X86_CR4_OSFXSR);
+ set_in_cr4(X86_CR4_OSXMMEXCPT);
+
+ write_cr0(oldcr0 & ~((1UL<<3)|(1UL<<2))); /* clear TS and EM */
+
+ mxcsr_feature_mask_init();
+ /* clean state in init */
+ current_thread_info()->status = 0;
+ clear_used_math();
+}
+
+void init_fpu(struct task_struct *child)
+{
+ if (tsk_used_math(child)) {
+ if (child == current)
+ unlazy_fpu(child);
+ return;
+ }
+ memset(&child->thread.i387.fxsave, 0, sizeof(struct i387_fxsave_struct));
+ child->thread.i387.fxsave.cwd = 0x37f;
+ child->thread.i387.fxsave.mxcsr = 0x1f80;
+ /* only the device not available exception or ptrace can call init_fpu */
+ set_stopped_child_used_math(child);
+}
+
+/*
+ * Signal frame handlers.
+ */
+
+int save_i387(struct _fpstate __user *buf)
+{
+ struct task_struct *tsk = current;
+ int err = 0;
+
+ BUILD_BUG_ON(sizeof(struct user_i387_struct) !=
+ sizeof(tsk->thread.i387.fxsave));
+
+ if ((unsigned long)buf % 16)
+ printk("save_i387: bad fpstate %p\n",buf);
+
+ if (!used_math())
+ return 0;
+ clear_used_math(); /* trigger finit */
+ if (task_thread_info(tsk)->status & TS_USEDFPU) {
+ err = save_i387_checking((struct i387_fxsave_struct __user *)buf);
+ if (err) return err;
+ stts();
+ } else {
+ if (__copy_to_user(buf, &tsk->thread.i387.fxsave,
+ sizeof(struct i387_fxsave_struct)))
+ return -1;
+ }
+ return 1;
+}
+
+/*
+ * ptrace request handlers.
+ */
+
+int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *tsk)
+{
+ init_fpu(tsk);
+ return __copy_to_user(buf, &tsk->thread.i387.fxsave,
+ sizeof(struct user_i387_struct)) ? -EFAULT : 0;
+}
+
+int set_fpregs(struct task_struct *tsk, struct user_i387_struct __user *buf)
+{
+ if (__copy_from_user(&tsk->thread.i387.fxsave, buf,
+ sizeof(struct user_i387_struct)))
+ return -EFAULT;
+ return 0;
+}
+
+/*
+ * FPU state for core dumps.
+ */
+
+int dump_fpu( struct pt_regs *regs, struct user_i387_struct *fpu )
+{
+ struct task_struct *tsk = current;
+
+ if (!used_math())
+ return 0;
+
+ unlazy_fpu(tsk);
+ memcpy(fpu, &tsk->thread.i387.fxsave, sizeof(struct user_i387_struct));
+ return 1;
+}
+
+int dump_task_fpu(struct task_struct *tsk, struct user_i387_struct *fpu)
+{
+ int fpvalid = !!tsk_used_math(tsk);
+
+ if (fpvalid) {
+ if (tsk == current)
+ unlazy_fpu(tsk);
+ memcpy(fpu, &tsk->thread.i387.fxsave, sizeof(struct user_i387_struct));
+}
+ return fpvalid;
+}