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linux-uconsole/arch/sparc/include/asm
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Peter Zijlstra a03a2426ea arch: Introduce smp_load_acquire(), smp_store_release() 
A number of situations currently require the heavyweight smp_mb(),
even though there is no need to order prior stores against later
loads.  Many architectures have much cheaper ways to handle these
situations, but the Linux kernel currently has no portable way
to make use of them.

This commit therefore supplies smp_load_acquire() and
smp_store_release() to remedy this situation.  The new
smp_load_acquire() primitive orders the specified load against
any subsequent reads or writes, while the new smp_store_release()
primitive orders the specifed store against any prior reads or
writes.  These primitives allow array-based circular FIFOs to be
implemented without an smp_mb(), and also allow a theoretical
hole in rcu_assign_pointer() to be closed at no additional
expense on most architectures.

In addition, the RCU experience transitioning from explicit
smp_read_barrier_depends() and smp_wmb() to rcu_dereference()
and rcu_assign_pointer(), respectively resulted in substantial
improvements in readability.  It therefore seems likely that
replacing other explicit barriers with smp_load_acquire() and
smp_store_release() will provide similar benefits.  It appears
that roughly half of the explicit barriers in core kernel code
might be so replaced.

[Changelog by PaulMck]
(cherry picked from commit 47933ad41a)

Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/20131213150640.908486364@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-07 16:42:29 -07:00
..
agp.h agp: kill phys_to_gart() and gart_to_phys() 2009-08-03 09:05:00 +01:00
apb.h
asm-offsets.h kbuild: move asm-offsets.h to include/generated 2009-12-12 13:08:14 +01:00
asm.h sparc: Add asm/asm.h 2008-12-09 00:50:13 -08:00
asmmacro.h sparc32: add support for run-time patching of leon/sun single instructions 2012-05-27 23:52:43 -07:00
atomic.h
atomic_32.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
atomic_64.h sparc: Support atomic64_dec_if_positive properly. 2012-11-09 19:37:59 -08:00
auxio.h
auxio_32.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
auxio_64.h
backoff.h sparc64: Improvde documentation and readability of atomic backoff code. 2012-10-28 13:04:47 -07:00
barrier.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
barrier_32.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
barrier_64.h arch: Introduce smp_load_acquire(), smp_store_release() 2014-10-07 16:42:29 -07:00
bbc.h
bitext.h
bitops.h
bitops_32.h bitops: remove minix bitops from asm/bitops.h 2011-03-23 19:46:22 -07:00
bitops_64.h sparc: Use popc when possible for ffs/__ffs/ffz. 2011-08-02 21:28:53 -07:00
btext.h sparc64: Faster early-boot framebuffer console. 2009-11-27 17:33:43 -08:00
bug.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
bugs.h sparc64: Implement SSTATE purely using notifiers and initcalls. 2008-09-02 00:49:38 -07:00
cache.h sparc32: Remove completely unused code from asm/cache.h 2012-05-19 21:15:37 -07:00
cacheflush.h sparc32: use flushi when run-time patching in per_cpu_patch 2012-05-20 13:33:36 -07:00
cacheflush_32.h sparc32: Move cache and TLB flushes over to method ops. 2012-05-13 20:49:31 -07:00
cacheflush_64.h sparc32: use flushi when run-time patching in per_cpu_patch 2012-05-20 13:33:36 -07:00
cachetlb_32.h sparc32: Move cache and TLB flushes over to method ops. 2012-05-13 20:49:31 -07:00
chafsr.h
checksum.h
checksum_32.h
checksum_64.h
chmctrl.h
clock.h
cmpxchg.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
cmpxchg_32.h sparc32: remove runtime btfix support 2012-05-14 14:05:09 -07:00
cmpxchg_64.h sparc64: Provide cmpxchg64() 2013-03-20 11:06:55 -07:00
compat.h sparc64: Make montmul/montsqr/mpmul usable in 32-bit threads. 2012-10-26 15:18:37 -07:00
compat_signal.h sparc: switch to generic sigaltstack 2013-02-03 18:16:17 -05:00
contregs.h sparc32: Remove sun4{,c} control reg definitions from contregs.h. 2012-05-11 21:29:17 -07:00
cpu_type.h sparc32: Remove sun4 and sun4c from enum sparc_cpu. 2012-05-12 00:23:23 -07:00
cpudata.h
cpudata_32.h sparc32: generic clockevent support 2012-04-15 10:28:50 -07:00
cpudata_64.h sparc64: Use a seperate counter for timer interrupts and NMI checks, like x86. 2010-04-12 22:37:07 -07:00
current.h
dcr.h
dcu.h
delay.h
delay_32.h
delay_64.h
device.h of: remove asm/of_device.h 2010-07-24 09:57:52 -06:00
dma-mapping.h sparc: dma-mapping: support debug_dma_mapping_error 2012-11-17 13:20:38 +01:00
dma.h sparc32: Convert mmu_* interfaces from btfixup to method ops. 2012-05-13 13:57:05 -07:00
ebus_dma.h sparc: Move EBUS DMA interfaces into seperate header file. 2008-08-29 23:10:21 -07:00
ecc.h
eeprom.h
elf.h
elf_32.h default SET_PERSONALITY() in linux/elf.h 2013-02-26 02:46:08 -05:00
elf_64.h sparc64: Add detection for features new in SPARC-T4. 2012-08-18 23:02:36 -07:00
estate.h
fb.h sparc: Really fix "console=" for serial consoles. 2010-08-16 12:26:09 -07:00
fbio.h UAPI: (Scripted) Disintegrate arch/sparc/include/asm 2012-10-09 09:47:43 +01:00
fhc.h sparc64: Rewrite central driver. 2008-08-31 20:56:15 -07:00
floppy.h
floppy_32.h sparc: Kill mmu_{un,}lockarea(). 2012-05-13 13:23:16 -07:00
floppy_64.h sparc64: Remove pointless assignment in floppy support. 2012-05-14 20:59:25 -07:00
fpumacro.h
ftrace.h sparc64: Add proper dynamic ftrace support. 2009-06-16 04:56:53 -07:00
futex.h
futex_32.h
futex_64.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
gpio.h gpiolib/arches: Centralise bolierplate asm/gpio.h 2012-05-11 18:00:14 -06:00
hardirq.h
hardirq_32.h sparc32: convert to asm-generic/hardirq.h 2009-10-01 13:45:13 -07:00
hardirq_64.h
head.h
head_32.h sparc: Consistently use 'wr' and 'rd' instructions for ASRs. 2013-04-06 17:51:48 -04:00
head_64.h
hibernate.h sparc64: Hibernation support 2013-03-20 11:06:54 -07:00
highmem.h sparc32: move kmap_init() to highmem.c 2012-07-26 16:46:17 -07:00
hugetlb.h mm/hugetlb: add more arch-defined huge_pte functions 2013-04-29 15:54:33 -07:00
hvtramp.h
hw_irq.h
hypervisor.h sparc64: Add hypervisor interfaces for SPARC-T4 perf counter access. 2012-08-18 23:03:53 -07:00
ide.h
idprom.h
intr_queue.h
io-unit.h sparc32: Kill iounit_map_dma_*(). 2008-08-29 02:15:23 -07:00
io.h sparc: add {read,write}*_be routines 2011-05-12 13:44:29 -07:00
io_32.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
io_64.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
ioctls.h UAPI: (Scripted) Disintegrate arch/sparc/include/asm 2012-10-09 09:47:43 +01:00
iommu.h
iommu_32.h sparc: Remove generic SBUS probing layer. 2008-08-29 02:15:21 -07:00
iommu_64.h sparc64: Get rid of pci_controller_info. 2008-09-10 23:07:41 -07:00
irq.h
irq_32.h sparc32: genirq support 2011-04-19 22:11:40 -07:00
irq_64.h nmi watchdog: do not use cpp symbol in Kconfig 2012-03-23 16:58:31 -07:00
irqflags.h
irqflags_32.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
irqflags_64.h sparc/irqs: Do not trace arch_local_{*,irq_*} functions 2011-07-06 08:00:29 -07:00
jump_label.h static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]() 2012-02-24 10:05:59 +01:00
Kbuild sparc: Switch to asm-generic/linkage.h 2013-06-19 02:08:20 -07:00
kdebug.h
kdebug_32.h sparc32: kernel/trace/trace.c wants DIE_OOPS 2008-11-01 21:44:01 -07:00
kdebug_64.h sparc64: Implement NMI watchdog on capable cpus. 2009-01-30 00:03:53 -08:00
kgdb.h
kmap_types.h kmap_types: make most arches use generic header file 2009-06-16 19:47:51 -07:00
kprobes.h
ldc.h
leon.h sparc32, leon: Remove separate "ticker" timer for SMP 2013-06-19 02:10:29 -07:00
leon_amba.h sparc32, leon: Remove separate "ticker" timer for SMP 2013-06-19 02:10:29 -07:00
leon_pci.h sparc32,leon: add support for PCI busn resource for GRPCI2 2013-03-20 11:06:53 -07:00
lsu.h
machines.h sparc32: Trivial removal of sun4c references in comments. 2012-05-12 00:35:45 -07:00
mbus.h sparc32: Remove cypress cpu support. 2012-05-15 10:22:00 -07:00
mc146818rtc.h
mc146818rtc_32.h
mc146818rtc_64.h sparc64: Use generic CMOS driver. 2008-08-29 14:16:48 -07:00
mdesc.h sparc64: Probe cpu page size support more portably. 2012-09-06 19:01:25 -07:00
memctrl.h sparc64: Add generic interface for registering a dimm printing handler. 2008-08-24 22:08:34 -07:00
mman.h UAPI: (Scripted) Disintegrate arch/sparc/include/asm 2012-10-09 09:47:43 +01:00
mmu.h
mmu_32.h sparc32: add irq + smp declarations to headers 2011-03-16 18:19:08 -07:00
mmu_64.h sparc64: Support transparent huge pages. 2012-10-09 16:23:06 +09:00
mmu_context.h
mmu_context_32.h sparc32: centralize all mmu context handling in srmmu.c 2012-07-26 16:46:16 -07:00
mmu_context_64.h sparc64: Do not save/restore interrupts in get_new_mmu_context() 2013-04-08 22:50:47 -04:00
mmzone.h Fix node_start/end_pfn() definition for mm/page_cgroup.c 2011-06-27 14:13:09 -07:00
msi.h
mxcc.h
nmi.h sparc64: Initial hw perf counter support. 2009-09-10 06:28:20 -07:00
ns87303.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
obio.h sparc32: move smp ipi to method ops 2012-05-14 14:05:07 -07:00
openprom.h sparc: Pass buffer pointer all the way down to prom_{get,put}char(). 2010-11-30 14:33:29 -08:00
oplib.h
oplib_32.h sparc: fix format string argument for prom_printf() 2012-10-02 23:20:34 -04:00
oplib_64.h sparc: fix format string argument for prom_printf() 2012-10-02 23:20:34 -04:00
page.h
page_32.h sparc32: drop sparc_unmapped_base 2012-07-26 16:46:16 -07:00
page_64.h sparc64: Fix tsb_grow() in atomic context. 2013-02-20 09:46:08 -08:00
parport.h SPARC: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
pbm.h
pci.h pci-dma: add linux/pci-dma.h to linux/pci.h 2010-03-12 15:52:42 -08:00
pci_32.h PCI: collapse pcibios_resource_to_bus 2012-02-23 20:19:04 -07:00
pci_64.h PCI: collapse pcibios_resource_to_bus 2012-02-23 20:19:04 -07:00
pcic.h sparc32: added CONFIG_PCIC_PCI Kconfig setting 2011-06-02 14:32:37 -07:00
pcr.h sparc64: Add PCR ops for SPARC-T4. 2012-08-18 23:26:19 -07:00
percpu.h
percpu_32.h
percpu_64.h sparc64: Get rid of real_setup_per_cpu_areas(). 2009-06-16 04:56:23 -07:00
perf_event.h perf, arch: Cleanup perf-pmu init vs lockup-detector 2010-11-26 15:14:56 +01:00
pgalloc.h
pgalloc_32.h sparc32: drop quicklist 2012-07-26 16:46:16 -07:00
pgalloc_64.h sparc64: Support transparent huge pages. 2012-10-09 16:23:06 +09:00
pgtable.h
pgtable_32.h sparc32: drop unused BAD_PAGE stuff 2012-07-26 16:46:16 -07:00
pgtable_64.h sparc64: Fix race in TLB batch processing. 2013-04-19 17:26:26 -04:00
pgtsrmmu.h sparc32: srmmu_probe now knows about leon too 2012-05-27 23:52:51 -07:00
pil.h sparc64: Reschedule KGDB capture to a software interrupt. 2009-03-18 23:51:57 -07:00
processor.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
processor_32.h sparc idle: rename pm_idle to sparc_idle 2013-02-17 23:36:56 -05:00
processor_64.h sparc64: Kill __ARCH_WANT_UNLOCKED_CTXSW 2013-03-20 12:09:01 -07:00
prom.h of/address: sparc: Declare of_iomap as an extern function for sparc again 2012-11-23 22:01:15 +00:00
psr.h UAPI: (Scripted) Disintegrate arch/sparc/include/asm 2012-10-09 09:47:43 +01:00
ptrace.h Merge commit '517ffce4e1' into arch-sparc 2012-11-16 20:49:06 -05:00
ross.h
rwsem.h rwsem: Move duplicate function prototypes to linux/rwsem.h 2011-01-27 12:30:39 +01:00
sbi.h
scatterlist.h remove needless ISA_DMA_THRESHOLD 2010-08-07 18:15:50 +02:00
scratchpad.h
seccomp.h x86-64: seccomp: fix 32/64 syscall hole 2009-03-02 15:41:30 -08:00
sections.h sparc32: add support for run-time patching of leon/sun single instructions 2012-05-27 23:52:43 -07:00
setup.h UAPI: (Scripted) Disintegrate arch/sparc/include/asm 2012-10-09 09:47:43 +01:00
sfafsr.h
sfp-machine.h
sfp-machine_32.h
sfp-machine_64.h
shmparam.h
shmparam_32.h sparc32: Remove sun4 and sun4c from enum sparc_cpu. 2012-05-12 00:23:23 -07:00
shmparam_64.h
sigcontext.h UAPI: (Scripted) Disintegrate arch/sparc/include/asm 2012-10-09 09:47:43 +01:00
siginfo.h UAPI: (Scripted) Disintegrate arch/sparc/include/asm 2012-10-09 09:47:43 +01:00
signal.h consolidate kernel-side struct sigaction declarations 2013-02-03 15:09:22 -05:00
smp.h
smp_32.h sparc:cleanup unused code in smp_32.h 2013-03-31 19:29:12 -04:00
smp_64.h sparc64: Add global PMU register dumping via sysrq. 2012-10-16 09:34:01 -07:00
sparsemem.h
spinlock.h
spinlock_32.h sparc32: unbreak arch_write_unlock() 2011-08-15 14:35:19 -07:00
spinlock_64.h sparc64: remove unnecessary macros from spinlock_64.h 2011-08-15 14:35:18 -07:00
spinlock_types.h locking: Convert raw_rwlock to arch_rwlock 2009-12-14 23:55:32 +01:00
spitfire.h sparc64: correctly recognize SPARC64-X chips 2013-03-11 05:06:27 -07:00
stacktrace.h
starfire.h sparc64: Delete starfire_cpu_setup(). 2008-08-31 01:40:12 -07:00
string.h
string_32.h sparc32: Remove inline strncmp "optimization" for constant counts. 2012-05-11 19:53:29 -07:00
string_64.h sparc: Stop trying to be so fancy and use __builtin_{memcpy,memset}() 2009-12-10 23:32:10 -08:00
sunbpp.h
swift.h
switch_to.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
switch_to_32.h Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
switch_to_64.h sparc64: Fix race in TLB batch processing. 2013-04-19 17:26:26 -04:00
syscall.h tracing: Unify arch_syscall_addr() implementations 2010-02-17 13:07:21 +01:00
syscalls.h sparc32: switch to generic sys_execve() 2012-10-16 19:03:53 -04:00
termbits.h UAPI: (Scripted) Disintegrate arch/sparc/include/asm 2012-10-09 09:47:43 +01:00
termios.h UAPI: (Scripted) Disintegrate arch/sparc/include/asm 2012-10-09 09:47:43 +01:00
thread_info.h
thread_info_32.h arch: Consolidate tsk_is_polling() 2013-04-08 17:39:22 +02:00
thread_info_64.h arch: Consolidate tsk_is_polling() 2013-04-08 17:39:22 +02:00
timer.h
timer_32.h sparc32: remove runtime btfix support 2012-05-14 14:05:09 -07:00
timer_64.h SPARC: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
timex.h
timex_32.h sparc32: generic clockevent support 2012-04-15 10:28:50 -07:00
timex_64.h
tlb.h
tlb_32.h
tlb_64.h sparc: mmu_gather rework 2011-05-25 08:39:13 -07:00
tlbflush.h
tlbflush_32.h sparc32: Move cache and TLB flushes over to method ops. 2012-05-13 20:49:31 -07:00
tlbflush_64.h sparc64: Fix race in TLB batch processing. 2013-04-19 17:26:26 -04:00
topology.h
topology_32.h
topology_64.h sched/numa: Rewrite the CONFIG_NUMA sched domain support 2012-05-09 15:00:55 +02:00
trap_block.h sparc64: Store per-cpu offset in trap_block[] 2009-06-16 04:56:11 -07:00
traps.h UAPI: (Scripted) Disintegrate arch/sparc/include/asm 2012-10-09 09:47:43 +01:00
tsb.h sparc64: Fix huge PMD to PTE translation for sun4u in TLB miss handler. 2013-02-20 13:34:41 -08:00
tsunami.h
ttable.h sparc64: Make montmul/montsqr/mpmul usable in 32-bit threads. 2012-10-26 15:18:37 -07:00
turbosparc.h
uaccess.h sparc: Fix user_addr_max() definition. 2012-05-24 13:41:58 -07:00
uaccess_32.h sparc: use the new generic strnlen_user() function 2012-05-26 11:33:54 -07:00
uaccess_64.h sparc64: clear syscall_noerror on the entry to syscall, not on the exit 2012-10-14 19:26:52 -04:00
unaligned.h
unistd.h consolidate cond_syscall and SYSCALL_ALIAS declarations 2013-03-03 22:55:19 -05:00
upa.h
user.h
vaddrs.h sparc32: drop fixmap.h 2012-07-26 16:46:16 -07:00
vga.h BUG: headers with BUG/BUG_ON etc. need linux/bug.h 2012-03-04 17:54:34 -05:00
viking.h
vio.h powerpc+sparc/vio: Modernize driver registration 2012-03-28 11:33:24 +11:00
visasm.h sparc64: Fix sparse warnings in visemul.c 2008-09-11 23:46:40 -07:00
winmacro.h sparc32: Implement hard_smp_processor_id() via instruction patching. 2012-05-14 13:31:38 -07:00
xor.h
xor_32.h
xor_64.h sparc64: Future proof Niagara cpu detection. 2011-09-16 14:21:33 -07:00