Merge drm/drm-next into drm-intel-next

Sync up with upstream.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

1 files changed, 25 insertions, 2 deletions

diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h
index a5aba4ab0224..ed33a14188f6 100644
--- a/arch/x86/include/asm/fpu/api.h
+++ b/arch/x86/include/asm/fpu/api.h
@@ -16,14 +16,37 @@
  * Use kernel_fpu_begin/end() if you intend to use FPU in kernel context. It
  * disables preemption so be careful if you intend to use it for long periods
  * of time.
- * If you intend to use the FPU in softirq you need to check first with
+ * If you intend to use the FPU in irq/softirq you need to check first with
  * irq_fpu_usable() if it is possible.
  */
-extern void kernel_fpu_begin(void);
+
+/* Kernel FPU states to initialize in kernel_fpu_begin_mask() */
+#define KFPU_387	_BITUL(0)	/* 387 state will be initialized */
+#define KFPU_MXCSR	_BITUL(1)	/* MXCSR will be initialized */
+
+extern void kernel_fpu_begin_mask(unsigned int kfpu_mask);
 extern void kernel_fpu_end(void);
 extern bool irq_fpu_usable(void);
 extern void fpregs_mark_activate(void);
 
+/* Code that is unaware of kernel_fpu_begin_mask() can use this */
+static inline void kernel_fpu_begin(void)
+{
+#ifdef CONFIG_X86_64
+	/*
+	 * Any 64-bit code that uses 387 instructions must explicitly request
+	 * KFPU_387.
+	 */
+	kernel_fpu_begin_mask(KFPU_MXCSR);
+#else
+	/*
+	 * 32-bit kernel code may use 387 operations as well as SSE2, etc,
+	 * as long as it checks that the CPU has the required capability.
+	 */
+	kernel_fpu_begin_mask(KFPU_387 | KFPU_MXCSR);
+#endif
+}
+
 /*
  * Use fpregs_lock() while editing CPU's FPU registers or fpu->state.
  * A context switch will (and softirq might) save CPU's FPU registers to