Merge tag 's390-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Alexander Gordeev:

 - Add machine variable capacity information to /proc/sysinfo.

 - Limit the waste of page tables and always align vmalloc area size and
   base address on segment boundary.

 - Fix a memory leak when an attempt to register interruption sub class
   (ISC) for the adjunct-processor (AP) guest failed.

 - Reset response code AP_RESPONSE_INVALID_GISA to understandable by
   guest AP_RESPONSE_INVALID_ADDRESS in response to a failed
   interruption sub class (ISC) registration attempt.

 - Improve reaction to adjunct-processor (AP)
   AP_RESPONSE_OTHERWISE_CHANGED response code when enabling interrupts
   on behalf of a guest.

 - Fix incorrect sysfs 'status' attribute of adjunct-processor (AP)
   queue device bound to the vfio_ap device driver when the mediated
   device is attached to a guest, but the queue device is not passed
   through.

 - Rework struct ap_card to hold the whole adjunct-processor (AP) card
   hardware information. As result, all the ugly bit checks are replaced
   by simple evaluations of the required bit fields.

 - Improve handling of some weird scenarios between service element (SE)
   host and SE guest with adjunct-processor (AP) pass-through support.

 - Change local_ctl_set_bit() and local_ctl_clear_bit() so they return
   the previous value of the to be changed control register. This is
   useful if a bit is only changed temporarily and the previous content
   needs to be restored.

 - The kernel starts with machine checks disabled and is expected to
   enable it once trap_init() is called. However the implementation
   allows machine checks early. Consistently enable it in trap_init()
   only.

 - local_mcck_disable() and local_mcck_enable() assume that machine
   checks are always enabled. Instead implement and use
   local_mcck_save() and local_mcck_restore() to disable machine checks
   and restore the previous state.

 - Modification of floating point control (FPC) register of a traced
   process using ptrace interface may lead to corruption of the FPC
   register of the tracing process. Fix this.

 - kvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point
   control (FPC) register in vCPU, but may lead to corruption of the FPC
   register of the host process. Fix this.

 - Use READ_ONCE() to read a vCPU floating point register value from the
   memory mapped area. This avoids that, depending on code generation, a
   different value is tested for validity than the one that is used.

 - Get rid of test_fp_ctl(), since it is quite subtle to use it
   correctly. Instead copy a new floating point control register value
   into its save area and test the validity of the new value when
   loading it.

 - Remove superfluous save_fpu_regs() call.

 - Remove s390 support for ARCH_WANTS_DYNAMIC_TASK_STRUCT. All machines
   provide the vector facility since many years and the need to make the
   task structure size dependent on the vector facility does not exist.

 - Remove the "novx" kernel command line option, as the vector code runs
   without any problems since many years.

 - Add the vector facility to the z13 architecture level set (ALS). All
   hypervisors support the vector facility since many years. This allows
   compile time optimizations of the kernel.

 - Get rid of MACHINE_HAS_VX and replace it with cpu_has_vx(). As
   result, the compiled code will have less runtime checks and less
   code.

 - Convert pgste_get_lock() and pgste_set_unlock() ASM inlines to C.

 - Convert the struct subchannel spinlock from pointer to member.

* tag 's390-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (24 commits)
  Revert "s390: update defconfigs"
  s390/cio: make sch->lock spinlock pointer a member
  s390: update defconfigs
  s390/mm: convert pgste locking functions to C
  s390/fpu: get rid of MACHINE_HAS_VX
  s390/als: add vector facility to z13 architecture level set
  s390/fpu: remove "novx" option
  s390/fpu: remove ARCH_WANTS_DYNAMIC_TASK_STRUCT support
  KVM: s390: remove superfluous save_fpu_regs() call
  s390/fpu: get rid of test_fp_ctl()
  KVM: s390: use READ_ONCE() to read fpc register value
  KVM: s390: fix setting of fpc register
  s390/ptrace: handle setting of fpc register correctly
  s390/nmi: implement and use local_mcck_save() / local_mcck_restore()
  s390/nmi: consistently enable machine checks in trap_init()
  s390/ctlreg: return old register contents when changing bits
  s390/ap: handle outband SE bind state change
  s390/ap: store TAPQ hwinfo in struct ap_card
  s390/vfio-ap: fix sysfs status attribute for AP queue devices
  s390/vfio-ap: improve reaction to response code 07 from PQAP(AQIC) command
  ...

1 files changed, 21 insertions, 14 deletions

diff --git a/arch/s390/include/asm/fpu/api.h b/arch/s390/include/asm/fpu/api.h
index 9acf48e53a87..d6ca8bc6ca68 100644
--- a/arch/s390/include/asm/fpu/api.h
+++ b/arch/s390/include/asm/fpu/api.h
@@ -46,26 +46,33 @@
 
 #include <linux/preempt.h>
 #include <asm/asm-extable.h>
+#include <asm/fpu/internal.h>
 
 void save_fpu_regs(void);
 void load_fpu_regs(void);
 void __load_fpu_regs(void);
 
-static inline int test_fp_ctl(u32 fpc)
+/**
+ * sfpc_safe - Set floating point control register safely.
+ * @fpc: new value for floating point control register
+ *
+ * Set floating point control register. This may lead to an exception,
+ * since a saved value may have been modified by user space (ptrace,
+ * signal return, kvm registers) to an invalid value. In such a case
+ * set the floating point control register to zero.
+ */
+static inline void sfpc_safe(u32 fpc)
 {
-	u32 orig_fpc;
-	int rc;
-
-	asm volatile(
-		"	efpc    %1\n"
-		"	sfpc	%2\n"
-		"0:	sfpc	%1\n"
-		"	la	%0,0\n"
-		"1:\n"
-		EX_TABLE(0b,1b)
-		: "=d" (rc), "=&d" (orig_fpc)
-		: "d" (fpc), "0" (-EINVAL));
-	return rc;
+	asm volatile("\n"
+		"0:	sfpc	%[fpc]\n"
+		"1:	nopr	%%r7\n"
+		".pushsection .fixup, \"ax\"\n"
+		"2:	lghi	%[fpc],0\n"
+		"	jg	0b\n"
+		".popsection\n"
+		EX_TABLE(1b, 2b)
+		: [fpc] "+d" (fpc)
+		: : "memory");
 }
 
 #define KERNEL_FPC		1