Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Martin Schwidefsky:
 "The new features and main improvements in this merge for v4.9

   - Support for the UBSAN sanitizer

   - Set HAVE_EFFICIENT_UNALIGNED_ACCESS, it improves the code in some
     places

   - Improvements for the in-kernel fpu code, in particular the overhead
     for multiple consecutive in kernel fpu users is recuded

   - Add a SIMD implementation for the RAID6 gen and xor operations

   - Add RAID6 recovery based on the XC instruction

   - The PCI DMA flush logic has been improved to increase the speed of
     the map / unmap operations

   - The time synchronization code has seen some updates

  And bug fixes all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits)
  s390/con3270: fix insufficient space padding
  s390/con3270: fix use of uninitialised data
  MAINTAINERS: update DASD maintainer
  s390/cio: fix accidental interrupt enabling during resume
  s390/dasd: add missing \n to end of dev_err messages
  s390/config: Enable config options for Docker
  s390/dasd: make query host access interruptible
  s390/dasd: fix panic during offline processing
  s390/dasd: fix hanging offline processing
  s390/pci_dma: improve lazy flush for unmap
  s390/pci_dma: split dma_update_trans
  s390/pci_dma: improve map_sg
  s390/pci_dma: simplify dma address calculation
  s390/pci_dma: remove dma address range check
  iommu/s390: simplify registration of I/O address translation parameters
  s390: migrate exception table users off module.h and onto extable.h
  s390: export header for CLP ioctl
  s390/vmur: fix irq pointer dereference in int handler
  s390/dasd: add missing KOBJ_CHANGE event for unformatted devices
  s390: enable UBSAN
  ...

1 files changed, 21 insertions, 11 deletions

diff --git a/arch/s390/include/asm/fpu/api.h b/arch/s390/include/asm/fpu/api.h
index 6aba6fc406ad..02124d66bfb5 100644
--- a/arch/s390/include/asm/fpu/api.h
+++ b/arch/s390/include/asm/fpu/api.h
@@ -64,18 +64,18 @@ static inline int test_fp_ctl(u32 fpc)
 	return rc;
 }
 
-#define KERNEL_VXR_V0V7		1
-#define KERNEL_VXR_V8V15	2
-#define KERNEL_VXR_V16V23	4
-#define KERNEL_VXR_V24V31	8
-#define KERNEL_FPR		16
-#define KERNEL_FPC		256
+#define KERNEL_FPC		1
+#define KERNEL_VXR_V0V7		2
+#define KERNEL_VXR_V8V15	4
+#define KERNEL_VXR_V16V23	8
+#define KERNEL_VXR_V24V31	16
 
 #define KERNEL_VXR_LOW		(KERNEL_VXR_V0V7|KERNEL_VXR_V8V15)
 #define KERNEL_VXR_MID		(KERNEL_VXR_V8V15|KERNEL_VXR_V16V23)
 #define KERNEL_VXR_HIGH		(KERNEL_VXR_V16V23|KERNEL_VXR_V24V31)
 
-#define KERNEL_FPU_MASK		(KERNEL_VXR_LOW|KERNEL_VXR_HIGH|KERNEL_FPR)
+#define KERNEL_VXR		(KERNEL_VXR_LOW|KERNEL_VXR_HIGH)
+#define KERNEL_FPR		(KERNEL_FPC|KERNEL_VXR_V0V7)
 
 struct kernel_fpu;
 
@@ -87,18 +87,28 @@ struct kernel_fpu;
  * Prefer using the kernel_fpu_begin()/kernel_fpu_end() pair of functions.
  */
 void __kernel_fpu_begin(struct kernel_fpu *state, u32 flags);
-void __kernel_fpu_end(struct kernel_fpu *state);
+void __kernel_fpu_end(struct kernel_fpu *state, u32 flags);
 
 
 static inline void kernel_fpu_begin(struct kernel_fpu *state, u32 flags)
 {
 	preempt_disable();
-	__kernel_fpu_begin(state, flags);
+	state->mask = S390_lowcore.fpu_flags;
+	if (!test_cpu_flag(CIF_FPU))
+		/* Save user space FPU state and register contents */
+		save_fpu_regs();
+	else if (state->mask & flags)
+		/* Save FPU/vector register in-use by the kernel */
+		__kernel_fpu_begin(state, flags);
+	S390_lowcore.fpu_flags |= flags;
 }
 
-static inline void kernel_fpu_end(struct kernel_fpu *state)
+static inline void kernel_fpu_end(struct kernel_fpu *state, u32 flags)
 {
-	__kernel_fpu_end(state);
+	S390_lowcore.fpu_flags = state->mask;
+	if (state->mask & flags)
+		/* Restore FPU/vector register in-use by the kernel */
+		__kernel_fpu_end(state, flags);
 	preempt_enable();
 }