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

Pull s390 updates from Heiko Carstens:
 "The main thing in this merge is the defense for the Spectre
  vulnerabilities. But there are other updates as well, the changes in
  more detail:

   - An s390 specific implementation of the array_index_mask_nospec
     function to the defense against spectre v1

   - Two patches to utilize the new PPA-12/PPA-13 instructions to run
     the kernel and/or user space with reduced branch predicton.

   - The s390 variant of the 'retpoline' spectre v2 defense called
     'expoline'. There is no return instruction for s390, instead an
     indirect branch is used for function return

     The s390 defense mechanism for indirect branches works by using an
     execute-type instruction with the indirect branch as the target of
     the execute. In effect that turns off the prediction for the
     indirect branch.

   - Scrub registers in entry.S that contain user controlled values to
     prevent the speculative use of these values.

   - Re-add the second parameter for the s390 specific runtime
     instrumentation system call and move the header file to uapi. The
     second parameter will continue to do nothing but older kernel
     versions only accepted valid real-time signal numbers. The details
     will be documented in the man-page for the system call.

   - Corrections and improvements for the s390 specific documentation

   - Add a line to /proc/sysinfo to display the CPU model dependent
     license-internal-code identifier

   - A header file include fix for eadm.

   - An error message fix in the kprobes code.

   - The removal of an outdated ARCH_xxx select statement"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/kconfig: Remove ARCH_WANTS_PROT_NUMA_PROT_NONE select
  s390: introduce execute-trampolines for branches
  s390: run user space and KVM guests with modified branch prediction
  s390: add options to change branch prediction behaviour for the kernel
  s390/alternative: use a copy of the facility bit mask
  s390: add optimized array_index_mask_nospec
  s390: scrub registers on kernel entry and KVM exit
  s390/cio: fix kernel-doc usage
  s390/runtime_instrumentation: re-add signum system call parameter
  s390/cpum_cf: correct counter number of LAST_HOST_TRANSLATIONS
  s390/kprobes: Fix %p uses in error messages
  s390/runtime instrumentation: provide uapi header file
  s390/sysinfo: add and display licensed internal code identifier
  s390/docs: reword airq section
  s390/docs: mention subchannel types
  s390/cmf: fix kerneldoc
  s390/eadm: fix CONFIG_BLOCK include dependency

1 files changed, 74 insertions, 0 deletions

diff --git a/arch/s390/include/uapi/asm/runtime_instr.h b/arch/s390/include/uapi/asm/runtime_instr.h
new file mode 100644
index 000000000000..45c9ec984e6b
--- /dev/null
+++ b/arch/s390/include/uapi/asm/runtime_instr.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _S390_UAPI_RUNTIME_INSTR_H
+#define _S390_UAPI_RUNTIME_INSTR_H
+
+#include <linux/types.h>
+
+#define S390_RUNTIME_INSTR_START	0x1
+#define S390_RUNTIME_INSTR_STOP		0x2
+
+struct runtime_instr_cb {
+	__u64 rca;
+	__u64 roa;
+	__u64 rla;
+
+	__u32 v			: 1;
+	__u32 s			: 1;
+	__u32 k			: 1;
+	__u32 h			: 1;
+	__u32 a			: 1;
+	__u32 reserved1		: 3;
+	__u32 ps		: 1;
+	__u32 qs		: 1;
+	__u32 pc		: 1;
+	__u32 qc		: 1;
+	__u32 reserved2		: 1;
+	__u32 g			: 1;
+	__u32 u			: 1;
+	__u32 l			: 1;
+	__u32 key		: 4;
+	__u32 reserved3		: 8;
+	__u32 t			: 1;
+	__u32 rgs		: 3;
+
+	__u32 m			: 4;
+	__u32 n			: 1;
+	__u32 mae		: 1;
+	__u32 reserved4		: 2;
+	__u32 c			: 1;
+	__u32 r			: 1;
+	__u32 b			: 1;
+	__u32 j			: 1;
+	__u32 e			: 1;
+	__u32 x			: 1;
+	__u32 reserved5		: 2;
+	__u32 bpxn		: 1;
+	__u32 bpxt		: 1;
+	__u32 bpti		: 1;
+	__u32 bpni		: 1;
+	__u32 reserved6		: 2;
+
+	__u32 d			: 1;
+	__u32 f			: 1;
+	__u32 ic		: 4;
+	__u32 dc		: 4;
+
+	__u64 reserved7;
+	__u64 sf;
+	__u64 rsic;
+	__u64 reserved8;
+} __packed __aligned(8);
+
+static inline void load_runtime_instr_cb(struct runtime_instr_cb *cb)
+{
+	asm volatile(".insn	rsy,0xeb0000000060,0,0,%0"	/* LRIC */
+		: : "Q" (*cb));
+}
+
+static inline void store_runtime_instr_cb(struct runtime_instr_cb *cb)
+{
+	asm volatile(".insn	rsy,0xeb0000000061,0,0,%0"	/* STRIC */
+		: "=Q" (*cb) : : "cc");
+}
+
+#endif /* _S390_UAPI_RUNTIME_INSTR_H */