Merge branch 'next' (accumulated 3.16 merge window patches) into master

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

1 files changed, 16 insertions, 7 deletions

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index fd3e3924041..5901480bfdc 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -21,6 +21,7 @@
 #endif
 
 #include <asm/ptrace.h>
+#include <asm/thread_info.h>
 
 /*
  * Stack pushing/popping (register pairs only). Equivalent to store decrement
@@ -68,23 +69,31 @@
 	msr	daifclr, #8
 	.endm
 
-	.macro	disable_step, tmp
+	.macro	disable_step_tsk, flgs, tmp
+	tbz	\flgs, #TIF_SINGLESTEP, 9990f
 	mrs	\tmp, mdscr_el1
 	bic	\tmp, \tmp, #1
 	msr	mdscr_el1, \tmp
+	isb	// Synchronise with enable_dbg
+9990:
 	.endm
 
-	.macro	enable_step, tmp
+	.macro	enable_step_tsk, flgs, tmp
+	tbz	\flgs, #TIF_SINGLESTEP, 9990f
+	disable_dbg
 	mrs	\tmp, mdscr_el1
 	orr	\tmp, \tmp, #1
 	msr	mdscr_el1, \tmp
+9990:
 	.endm
 
-	.macro	enable_dbg_if_not_stepping, tmp
-	mrs	\tmp, mdscr_el1
-	tbnz	\tmp, #0, 9990f
-	enable_dbg
-9990:
+/*
+ * Enable both debug exceptions and interrupts. This is likely to be
+ * faster than two daifclr operations, since writes to this register
+ * are self-synchronising.
+ */
+	.macro	enable_dbg_and_irq
+	msr	daifclr, #(8 | 2)
 	.endm
 
 /*