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authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-23 13:08:53 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-23 13:08:53 +0100
commit0200fbdd431519d730b5d399a12840ec832b27cc (patch)
tree2b58f9e24b61b00e0550f106c95bfabc3b52cfdd /include/asm-generic
parentde3fbb2aa802a267dee2213ae7d5a1e19eb4294a (diff)
parent01a14bda11add9dcd4a59200f13834d634559935 (diff)
downloadtalos-obmc-linux-0200fbdd431519d730b5d399a12840ec832b27cc.tar.gz
talos-obmc-linux-0200fbdd431519d730b5d399a12840ec832b27cc.zip
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking and misc x86 updates from Ingo Molnar: "Lots of changes in this cycle - in part because locking/core attracted a number of related x86 low level work which was easier to handle in a single tree: - Linux Kernel Memory Consistency Model updates (Alan Stern, Paul E. McKenney, Andrea Parri) - lockdep scalability improvements and micro-optimizations (Waiman Long) - rwsem improvements (Waiman Long) - spinlock micro-optimization (Matthew Wilcox) - qspinlocks: Provide a liveness guarantee (more fairness) on x86. (Peter Zijlstra) - Add support for relative references in jump tables on arm64, x86 and s390 to optimize jump labels (Ard Biesheuvel, Heiko Carstens) - Be a lot less permissive on weird (kernel address) uaccess faults on x86: BUG() when uaccess helpers fault on kernel addresses (Jann Horn) - macrofy x86 asm statements to un-confuse the GCC inliner. (Nadav Amit) - ... and a handful of other smaller changes as well" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits) locking/lockdep: Make global debug_locks* variables read-mostly locking/lockdep: Fix debug_locks off performance problem locking/pvqspinlock: Extend node size when pvqspinlock is configured locking/qspinlock_stat: Count instances of nested lock slowpaths locking/qspinlock, x86: Provide liveness guarantee x86/asm: 'Simplify' GEN_*_RMWcc() macros locking/qspinlock: Rework some comments locking/qspinlock: Re-order code locking/lockdep: Remove duplicated 'lock_class_ops' percpu array x86/defconfig: Enable CONFIG_USB_XHCI_HCD=y futex: Replace spin_is_locked() with lockdep locking/lockdep: Make class->ops a percpu counter and move it under CONFIG_DEBUG_LOCKDEP=y x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs x86/extable: Macrofy inline assembly code to work around GCC inlining bugs x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs x86/refcount: Work around GCC inlining bug x86/objtool: Use asm macros to work around GCC inlining bugs ...
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/bug.h8
-rw-r--r--include/asm-generic/qrwlock.h7
-rw-r--r--include/asm-generic/qspinlock.h16
-rw-r--r--include/asm-generic/vmlinux.lds.h11
4 files changed, 24 insertions, 18 deletions
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 20561a60db9c..cdafa5edea49 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -17,10 +17,8 @@
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
-#ifdef CONFIG_BUG
-
-#ifdef CONFIG_GENERIC_BUG
struct bug_entry {
+#ifdef CONFIG_GENERIC_BUG
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
unsigned long bug_addr;
#else
@@ -35,8 +33,10 @@ struct bug_entry {
unsigned short line;
#endif
unsigned short flags;
-};
#endif /* CONFIG_GENERIC_BUG */
+};
+
+#ifdef CONFIG_BUG
/*
* Don't use BUG() or BUG_ON() unless there's really no way out; one
diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
index 0f7062bd55e5..36254d2da8e0 100644
--- a/include/asm-generic/qrwlock.h
+++ b/include/asm-generic/qrwlock.h
@@ -71,8 +71,8 @@ static inline int queued_write_trylock(struct qrwlock *lock)
if (unlikely(cnts))
return 0;
- return likely(atomic_cmpxchg_acquire(&lock->cnts,
- cnts, cnts | _QW_LOCKED) == cnts);
+ return likely(atomic_try_cmpxchg_acquire(&lock->cnts, &cnts,
+ _QW_LOCKED));
}
/**
* queued_read_lock - acquire read lock of a queue rwlock
@@ -96,8 +96,9 @@ static inline void queued_read_lock(struct qrwlock *lock)
*/
static inline void queued_write_lock(struct qrwlock *lock)
{
+ u32 cnts = 0;
/* Optimize for the unfair lock case where the fair flag is 0. */
- if (atomic_cmpxchg_acquire(&lock->cnts, 0, _QW_LOCKED) == 0)
+ if (likely(atomic_try_cmpxchg_acquire(&lock->cnts, &cnts, _QW_LOCKED)))
return;
queued_write_lock_slowpath(lock);
diff --git a/include/asm-generic/qspinlock.h b/include/asm-generic/qspinlock.h
index 9cc457597ddf..7541fa707f5b 100644
--- a/include/asm-generic/qspinlock.h
+++ b/include/asm-generic/qspinlock.h
@@ -66,10 +66,12 @@ static __always_inline int queued_spin_is_contended(struct qspinlock *lock)
*/
static __always_inline int queued_spin_trylock(struct qspinlock *lock)
{
- if (!atomic_read(&lock->val) &&
- (atomic_cmpxchg_acquire(&lock->val, 0, _Q_LOCKED_VAL) == 0))
- return 1;
- return 0;
+ u32 val = atomic_read(&lock->val);
+
+ if (unlikely(val))
+ return 0;
+
+ return likely(atomic_try_cmpxchg_acquire(&lock->val, &val, _Q_LOCKED_VAL));
}
extern void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
@@ -80,11 +82,11 @@ extern void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
*/
static __always_inline void queued_spin_lock(struct qspinlock *lock)
{
- u32 val;
+ u32 val = 0;
- val = atomic_cmpxchg_acquire(&lock->val, 0, _Q_LOCKED_VAL);
- if (likely(val == 0))
+ if (likely(atomic_try_cmpxchg_acquire(&lock->val, &val, _Q_LOCKED_VAL)))
return;
+
queued_spin_lock_slowpath(lock, val);
}
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index d7701d466b60..d0bcea7c8f84 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -253,10 +253,6 @@
STRUCT_ALIGN(); \
*(__tracepoints) \
/* implement dynamic printk debug */ \
- . = ALIGN(8); \
- __start___jump_table = .; \
- KEEP(*(__jump_table)) \
- __stop___jump_table = .; \
. = ALIGN(8); \
__start___verbose = .; \
KEEP(*(__verbose)) \
@@ -300,6 +296,12 @@
. = __start_init_task + THREAD_SIZE; \
__end_init_task = .;
+#define JUMP_TABLE_DATA \
+ . = ALIGN(8); \
+ __start___jump_table = .; \
+ KEEP(*(__jump_table)) \
+ __stop___jump_table = .;
+
/*
* Allow architectures to handle ro_after_init data on their
* own by defining an empty RO_AFTER_INIT_DATA.
@@ -308,6 +310,7 @@
#define RO_AFTER_INIT_DATA \
__start_ro_after_init = .; \
*(.data..ro_after_init) \
+ JUMP_TABLE_DATA \
__end_ro_after_init = .;
#endif
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