aboutsummaryrefslogtreecommitdiff
path: root/include/asm-x86/i387.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-x86/i387.h')
-rw-r--r--include/asm-x86/i387.h361
1 files changed, 358 insertions, 3 deletions
diff --git a/include/asm-x86/i387.h b/include/asm-x86/i387.h
index a8bbed34966..ba8105ca822 100644
--- a/include/asm-x86/i387.h
+++ b/include/asm-x86/i387.h
@@ -1,5 +1,360 @@
-#ifdef CONFIG_X86_32
-# include "i387_32.h"
+/*
+ * Copyright (C) 1994 Linus Torvalds
+ *
+ * Pentium III FXSR, SSE support
+ * General FPU state handling cleanups
+ * Gareth Hughes <gareth@valinux.com>, May 2000
+ * x86-64 work by Andi Kleen 2002
+ */
+
+#ifndef _ASM_X86_I387_H
+#define _ASM_X86_I387_H
+
+#include <linux/sched.h>
+#include <linux/kernel_stat.h>
+#include <linux/regset.h>
+#include <asm/processor.h>
+#include <asm/sigcontext.h>
+#include <asm/user.h>
+#include <asm/uaccess.h>
+
+extern void fpu_init(void);
+extern unsigned int mxcsr_feature_mask;
+extern void mxcsr_feature_mask_init(void);
+extern void init_fpu(struct task_struct *child);
+extern asmlinkage void math_state_restore(void);
+
+extern user_regset_active_fn fpregs_active, xfpregs_active;
+extern user_regset_get_fn fpregs_get, xfpregs_get, fpregs_soft_get;
+extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set;
+
+#ifdef CONFIG_IA32_EMULATION
+struct _fpstate_ia32;
+extern int save_i387_ia32(struct _fpstate_ia32 __user *buf);
+extern int restore_i387_ia32(struct _fpstate_ia32 __user *buf);
+#endif
+
+#ifdef CONFIG_X86_64
+
+/* Ignore delayed exceptions from user space */
+static inline void tolerant_fwait(void)
+{
+ asm volatile("1: fwait\n"
+ "2:\n"
+ " .section __ex_table,\"a\"\n"
+ " .align 8\n"
+ " .quad 1b,2b\n"
+ " .previous\n");
+}
+
+static inline int restore_fpu_checking(struct i387_fxsave_struct *fx)
+{
+ int err;
+
+ asm volatile("1: rex64/fxrstor (%[fx])\n\t"
+ "2:\n"
+ ".section .fixup,\"ax\"\n"
+ "3: movl $-1,%[err]\n"
+ " jmp 2b\n"
+ ".previous\n"
+ ".section __ex_table,\"a\"\n"
+ " .align 8\n"
+ " .quad 1b,3b\n"
+ ".previous"
+ : [err] "=r" (err)
+#if 0 /* See comment in __save_init_fpu() below. */
+ : [fx] "r" (fx), "m" (*fx), "0" (0));
+#else
+ : [fx] "cdaSDb" (fx), "m" (*fx), "0" (0));
+#endif
+ if (unlikely(err))
+ init_fpu(current);
+ return err;
+}
+
+#define X87_FSW_ES (1 << 7) /* Exception Summary */
+
+/* AMD CPUs don't save/restore FDP/FIP/FOP unless an exception
+ is pending. Clear the x87 state here by setting it to fixed
+ values. The kernel data segment can be sometimes 0 and sometimes
+ new user value. Both should be ok.
+ Use the PDA as safe address because it should be already in L1. */
+static inline void clear_fpu_state(struct i387_fxsave_struct *fx)
+{
+ if (unlikely(fx->swd & X87_FSW_ES))
+ asm volatile("fnclex");
+ alternative_input(ASM_NOP8 ASM_NOP2,
+ " emms\n" /* clear stack tags */
+ " fildl %%gs:0", /* load to clear state */
+ X86_FEATURE_FXSAVE_LEAK);
+}
+
+static inline int save_i387_checking(struct i387_fxsave_struct __user *fx)
+{
+ int err;
+
+ asm volatile("1: rex64/fxsave (%[fx])\n\t"
+ "2:\n"
+ ".section .fixup,\"ax\"\n"
+ "3: movl $-1,%[err]\n"
+ " jmp 2b\n"
+ ".previous\n"
+ ".section __ex_table,\"a\"\n"
+ " .align 8\n"
+ " .quad 1b,3b\n"
+ ".previous"
+ : [err] "=r" (err), "=m" (*fx)
+#if 0 /* See comment in __fxsave_clear() below. */
+ : [fx] "r" (fx), "0" (0));
+#else
+ : [fx] "cdaSDb" (fx), "0" (0));
+#endif
+ if (unlikely(err) && __clear_user(fx, sizeof(struct i387_fxsave_struct)))
+ err = -EFAULT;
+ /* No need to clear here because the caller clears USED_MATH */
+ return err;
+}
+
+static inline void __save_init_fpu(struct task_struct *tsk)
+{
+ /* Using "rex64; fxsave %0" is broken because, if the memory operand
+ uses any extended registers for addressing, a second REX prefix
+ will be generated (to the assembler, rex64 followed by semicolon
+ is a separate instruction), and hence the 64-bitness is lost. */
+#if 0
+ /* Using "fxsaveq %0" would be the ideal choice, but is only supported
+ starting with gas 2.16. */
+ __asm__ __volatile__("fxsaveq %0"
+ : "=m" (tsk->thread.i387.fxsave));
+#elif 0
+ /* Using, as a workaround, the properly prefixed form below isn't
+ accepted by any binutils version so far released, complaining that
+ the same type of prefix is used twice if an extended register is
+ needed for addressing (fix submitted to mainline 2005-11-21). */
+ __asm__ __volatile__("rex64/fxsave %0"
+ : "=m" (tsk->thread.i387.fxsave));
+#else
+ /* This, however, we can work around by forcing the compiler to select
+ an addressing mode that doesn't require extended registers. */
+ __asm__ __volatile__("rex64/fxsave %P2(%1)"
+ : "=m" (tsk->thread.i387.fxsave)
+ : "cdaSDb" (tsk),
+ "i" (offsetof(__typeof__(*tsk),
+ thread.i387.fxsave)));
+#endif
+ clear_fpu_state(&tsk->thread.i387.fxsave);
+ task_thread_info(tsk)->status &= ~TS_USEDFPU;
+}
+
+/*
+ * Signal frame handlers.
+ */
+
+static inline 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;
+ task_thread_info(tsk)->status &= ~TS_USEDFPU;
+ stts();
+ } else {
+ if (__copy_to_user(buf, &tsk->thread.i387.fxsave,
+ sizeof(struct i387_fxsave_struct)))
+ return -1;
+ }
+ return 1;
+}
+
+/*
+ * This restores directly out of user space. Exceptions are handled.
+ */
+static inline int restore_i387(struct _fpstate __user *buf)
+{
+ set_used_math();
+ if (!(task_thread_info(current)->status & TS_USEDFPU)) {
+ clts();
+ task_thread_info(current)->status |= TS_USEDFPU;
+ }
+ return restore_fpu_checking((__force struct i387_fxsave_struct *)buf);
+}
+
+#else /* CONFIG_X86_32 */
+
+static inline void tolerant_fwait(void)
+{
+ asm volatile("fnclex ; fwait");
+}
+
+static inline void restore_fpu(struct task_struct *tsk)
+{
+ /*
+ * The "nop" is needed to make the instructions the same
+ * length.
+ */
+ alternative_input(
+ "nop ; frstor %1",
+ "fxrstor %1",
+ X86_FEATURE_FXSR,
+ "m" ((tsk)->thread.i387.fxsave));
+}
+
+/* We need a safe address that is cheap to find and that is already
+ in L1 during context switch. The best choices are unfortunately
+ different for UP and SMP */
+#ifdef CONFIG_SMP
+#define safe_address (__per_cpu_offset[0])
#else
-# include "i387_64.h"
+#define safe_address (kstat_cpu(0).cpustat.user)
#endif
+
+/*
+ * These must be called with preempt disabled
+ */
+static inline void __save_init_fpu(struct task_struct *tsk)
+{
+ /* Use more nops than strictly needed in case the compiler
+ varies code */
+ alternative_input(
+ "fnsave %[fx] ;fwait;" GENERIC_NOP8 GENERIC_NOP4,
+ "fxsave %[fx]\n"
+ "bt $7,%[fsw] ; jnc 1f ; fnclex\n1:",
+ X86_FEATURE_FXSR,
+ [fx] "m" (tsk->thread.i387.fxsave),
+ [fsw] "m" (tsk->thread.i387.fxsave.swd) : "memory");
+ /* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception
+ is pending. Clear the x87 state here by setting it to fixed
+ values. safe_address is a random variable that should be in L1 */
+ alternative_input(
+ GENERIC_NOP8 GENERIC_NOP2,
+ "emms\n\t" /* clear stack tags */
+ "fildl %[addr]", /* set F?P to defined value */
+ X86_FEATURE_FXSAVE_LEAK,
+ [addr] "m" (safe_address));
+ task_thread_info(tsk)->status &= ~TS_USEDFPU;
+}
+
+/*
+ * Signal frame handlers...
+ */
+extern int save_i387(struct _fpstate __user *buf);
+extern int restore_i387(struct _fpstate __user *buf);
+
+#endif /* CONFIG_X86_64 */
+
+static inline void __unlazy_fpu(struct task_struct *tsk)
+{
+ if (task_thread_info(tsk)->status & TS_USEDFPU) {
+ __save_init_fpu(tsk);
+ stts();
+ } else
+ tsk->fpu_counter = 0;
+}
+
+static inline void __clear_fpu(struct task_struct *tsk)
+{
+ if (task_thread_info(tsk)->status & TS_USEDFPU) {
+ tolerant_fwait();
+ task_thread_info(tsk)->status &= ~TS_USEDFPU;
+ stts();
+ }
+}
+
+static inline void kernel_fpu_begin(void)
+{
+ struct thread_info *me = current_thread_info();
+ preempt_disable();
+ if (me->status & TS_USEDFPU)
+ __save_init_fpu(me->task);
+ else
+ clts();
+}
+
+static inline void kernel_fpu_end(void)
+{
+ stts();
+ preempt_enable();
+}
+
+#ifdef CONFIG_X86_64
+
+static inline void save_init_fpu(struct task_struct *tsk)
+{
+ __save_init_fpu(tsk);
+ stts();
+}
+
+#define unlazy_fpu __unlazy_fpu
+#define clear_fpu __clear_fpu
+
+#else /* CONFIG_X86_32 */
+
+/*
+ * These disable preemption on their own and are safe
+ */
+static inline void save_init_fpu(struct task_struct *tsk)
+{
+ preempt_disable();
+ __save_init_fpu(tsk);
+ stts();
+ preempt_enable();
+}
+
+static inline void unlazy_fpu(struct task_struct *tsk)
+{
+ preempt_disable();
+ __unlazy_fpu(tsk);
+ preempt_enable();
+}
+
+static inline void clear_fpu(struct task_struct *tsk)
+{
+ preempt_disable();
+ __clear_fpu(tsk);
+ preempt_enable();
+}
+
+#endif /* CONFIG_X86_64 */
+
+/*
+ * i387 state interaction
+ */
+static inline unsigned short get_fpu_cwd(struct task_struct *tsk)
+{
+ if (cpu_has_fxsr) {
+ return tsk->thread.i387.fxsave.cwd;
+ } else {
+ return (unsigned short)tsk->thread.i387.fsave.cwd;
+ }
+}
+
+static inline unsigned short get_fpu_swd(struct task_struct *tsk)
+{
+ if (cpu_has_fxsr) {
+ return tsk->thread.i387.fxsave.swd;
+ } else {
+ return (unsigned short)tsk->thread.i387.fsave.swd;
+ }
+}
+
+static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk)
+{
+ if (cpu_has_xmm) {
+ return tsk->thread.i387.fxsave.mxcsr;
+ } else {
+ return MXCSR_DEFAULT;
+ }
+}
+
+#endif /* _ASM_X86_I387_H */
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-22 16:45:55 +0000