Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

Pull x86 FPU updates from Thomas Gleixner:
 "A small set of updates for the FPU code:

   - Make the no387/nofxsr command line options useful by restricting
     them to 32bit and actually clearing all dependencies to prevent
     random crashes and malfunction.

   - Simplify and cleanup the kernel_fpu_*() helpers"

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Inline fpu__xstate_clear_all_cpu_caps()
  x86/fpu: Make 'no387' and 'nofxsr' command line options useful
  x86/fpu: Remove the fpu__save() export
  x86/fpu: Simplify kernel_fpu_begin()
  x86/fpu: Simplify kernel_fpu_end()

diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index 7e42b285c8562009510abd84d0e071e7ff084030..c6136d79f8c07f90148a22ed3d8bae7a1e0d0b46 100644 (file)
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -47,7 +47,6 @@ extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
 extern void __init update_regset_xstate_info(unsigned int size,
                                             u64 xstate_mask);
 
-void fpu__xstate_clear_all_cpu_caps(void);
 void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr);
 const void *get_xsave_field_ptr(int xfeature_nr);
 int using_compacted_format(void);

diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index 2c0bd38a44ab125c6a6f9627eea0cc69c3d882f5..e794e3860fc83ec234af8a1a55678c60ae3f3916 100644 (file)
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -20,6 +20,7 @@ struct cpuid_dep {
  * but it's difficult to tell that to the init reference checker.
  */
 static const struct cpuid_dep cpuid_deps[] = {
+       { X86_FEATURE_FXSR,             X86_FEATURE_FPU       },
        { X86_FEATURE_XSAVEOPT,         X86_FEATURE_XSAVE     },
        { X86_FEATURE_XSAVEC,           X86_FEATURE_XSAVE     },
        { X86_FEATURE_XSAVES,           X86_FEATURE_XSAVE     },
@@ -27,7 +28,11 @@ static const struct cpuid_dep cpuid_deps[] = {
        { X86_FEATURE_PKU,              X86_FEATURE_XSAVE     },
        { X86_FEATURE_MPX,              X86_FEATURE_XSAVE     },
        { X86_FEATURE_XGETBV1,          X86_FEATURE_XSAVE     },
+       { X86_FEATURE_CMOV,             X86_FEATURE_FXSR      },
+       { X86_FEATURE_MMX,              X86_FEATURE_FXSR      },
+       { X86_FEATURE_MMXEXT,           X86_FEATURE_MMX       },
        { X86_FEATURE_FXSR_OPT,         X86_FEATURE_FXSR      },
+       { X86_FEATURE_XSAVE,            X86_FEATURE_FXSR      },
        { X86_FEATURE_XMM,              X86_FEATURE_FXSR      },
        { X86_FEATURE_XMM2,             X86_FEATURE_XMM       },
        { X86_FEATURE_XMM3,             X86_FEATURE_XMM2      },

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 649fbc3fcf9f52ee2f5bbe3f524d9d4f62b5ac95..12c70840980e4b8aacf26541ff3814cbc4ebaf11 100644 (file)
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -43,18 +43,6 @@ static DEFINE_PER_CPU(bool, in_kernel_fpu);
  */
 DEFINE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx);
 
-static void kernel_fpu_disable(void)
-{
-       WARN_ON_FPU(this_cpu_read(in_kernel_fpu));
-       this_cpu_write(in_kernel_fpu, true);
-}
-
-static void kernel_fpu_enable(void)
-{
-       WARN_ON_FPU(!this_cpu_read(in_kernel_fpu));
-       this_cpu_write(in_kernel_fpu, false);
-}
-
 static bool kernel_fpu_disabled(void)
 {
        return this_cpu_read(in_kernel_fpu);
@@ -94,42 +82,33 @@ bool irq_fpu_usable(void)
 }
 EXPORT_SYMBOL(irq_fpu_usable);
 
-static void __kernel_fpu_begin(void)
+void kernel_fpu_begin(void)
 {
-       struct fpu *fpu = &current->thread.fpu;
+       preempt_disable();
 
        WARN_ON_FPU(!irq_fpu_usable());
+       WARN_ON_FPU(this_cpu_read(in_kernel_fpu));
 
-       kernel_fpu_disable();
+       this_cpu_write(in_kernel_fpu, true);
 
-       if (!(current->flags & PF_KTHREAD)) {
-               if (!test_thread_flag(TIF_NEED_FPU_LOAD)) {
-                       set_thread_flag(TIF_NEED_FPU_LOAD);
-                       /*
-                        * Ignore return value -- we don't care if reg state
-                        * is clobbered.
-                        */
-                       copy_fpregs_to_fpstate(fpu);
-               }
+       if (!(current->flags & PF_KTHREAD) &&
+           !test_thread_flag(TIF_NEED_FPU_LOAD)) {
+               set_thread_flag(TIF_NEED_FPU_LOAD);
+               /*
+                * Ignore return value -- we don't care if reg state
+                * is clobbered.
+                */
+               copy_fpregs_to_fpstate(&current->thread.fpu);
        }
        __cpu_invalidate_fpregs_state();
 }
-
-static void __kernel_fpu_end(void)
-{
-       kernel_fpu_enable();
-}
-
-void kernel_fpu_begin(void)
-{
-       preempt_disable();
-       __kernel_fpu_begin();
-}
 EXPORT_SYMBOL_GPL(kernel_fpu_begin);
 
 void kernel_fpu_end(void)
 {
-       __kernel_fpu_end();
+       WARN_ON_FPU(!this_cpu_read(in_kernel_fpu));
+
+       this_cpu_write(in_kernel_fpu, false);
        preempt_enable();
 }
 EXPORT_SYMBOL_GPL(kernel_fpu_end);
@@ -155,7 +134,6 @@ void fpu__save(struct fpu *fpu)
        trace_x86_fpu_after_save(fpu);
        fpregs_unlock();
 }
-EXPORT_SYMBOL_GPL(fpu__save);
 
 /*
  * Legacy x87 fpstate state init:

diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index ef0030e3fe6b989542e9e557a11bf14a13b3e674..6ce7e0a23268fdb20f5b5e43e16b40eb7d0e7561 100644 (file)
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -204,12 +204,6 @@ static void __init fpu__init_system_xstate_size_legacy(void)
         */
 
        if (!boot_cpu_has(X86_FEATURE_FPU)) {
-               /*
-                * Disable xsave as we do not support it if i387
-                * emulation is enabled.
-                */
-               setup_clear_cpu_cap(X86_FEATURE_XSAVE);
-               setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
                fpu_kernel_xstate_size = sizeof(struct swregs_state);
        } else {
                if (boot_cpu_has(X86_FEATURE_FXSR))
@@ -252,17 +246,20 @@ static void __init fpu__init_parse_early_param(void)
        char *argptr = arg;
        int bit;
 
+#ifdef CONFIG_X86_32
        if (cmdline_find_option_bool(boot_command_line, "no387"))
+#ifdef CONFIG_MATH_EMULATION
                setup_clear_cpu_cap(X86_FEATURE_FPU);
+#else
+               pr_err("Option 'no387' required CONFIG_MATH_EMULATION enabled.\n");
+#endif
 
-       if (cmdline_find_option_bool(boot_command_line, "nofxsr")) {
+       if (cmdline_find_option_bool(boot_command_line, "nofxsr"))
                setup_clear_cpu_cap(X86_FEATURE_FXSR);
-               setup_clear_cpu_cap(X86_FEATURE_FXSR_OPT);
-               setup_clear_cpu_cap(X86_FEATURE_XMM);
-       }
+#endif
 
        if (cmdline_find_option_bool(boot_command_line, "noxsave"))
-               fpu__xstate_clear_all_cpu_caps();
+               setup_clear_cpu_cap(X86_FEATURE_XSAVE);
 
        if (cmdline_find_option_bool(boot_command_line, "noxsaveopt"))
                setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 3c36dd1784db6c1662f036ca587fbbe3add5bd1b..7b4c52aa929fb47d097df85eb2900a6435bf9aa6 100644 (file)
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -67,15 +67,6 @@ static unsigned int xstate_comp_offsets[sizeof(xfeatures_mask)*8];
  */
 unsigned int fpu_user_xstate_size;
 
-/*
- * Clear all of the X86_FEATURE_* bits that are unavailable
- * when the CPU has no XSAVE support.
- */
-void fpu__xstate_clear_all_cpu_caps(void)
-{
-       setup_clear_cpu_cap(X86_FEATURE_XSAVE);
-}
-
 /*
  * Return whether the system supports a given xfeature.
  *
@@ -709,7 +700,7 @@ static void fpu__init_disable_system_xstate(void)
 {
        xfeatures_mask = 0;
        cr4_clear_bits(X86_CR4_OSXSAVE);
-       fpu__xstate_clear_all_cpu_caps();
+       setup_clear_cpu_cap(X86_FEATURE_XSAVE);
 }
 
 /*