linux/include/asm-generic
Marek Vasut d975440bf8 asm-generic: cmpxchg: avoid warnings from macro-ized cmpxchg() implementations
This change is similar to e001bbae71
ARM: cmpxchg: avoid warnings from macro-ized cmpxchg() implementations

A recent change in kernel/acct.c added a new warning for many
configurations using generic __xchg() implementation:

In file included from ./arch/nios2/include/asm/cmpxchg.h:12:0,
                 from include/asm-generic/atomic.h:18,
                 from arch/nios2/include/generated/asm/atomic.h:1,
                 from include/linux/atomic.h:4,
                 from include/linux/spinlock.h:406,
                 from include/linux/mmzone.h:7,
                 from include/linux/gfp.h:5,
                 from include/linux/mm.h:9,
                 from kernel/acct.c:46:
kernel/acct.c: In function 'acct_pin_kill':
include/asm-generic/cmpxchg.h:94:3: warning: value computed is not used [-Wunused-value]
  ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
   ^
include/asm-generic/cmpxchg.h:102:28: note: in expansion of macro 'cmpxchg_local'
 #define cmpxchg(ptr, o, n) cmpxchg_local((ptr), (o), (n))
                            ^
kernel/acct.c:177:2: note: in expansion of macro 'cmpxchg'
  cmpxchg(&acct->ns->bacct, pin, NULL);
  ^

The code is in fact correct, it's just a cmpxchg() call that
intentionally ignores the result, and no other code does that.  The
warning does not show up on x86 because of the way that its cmpxchg()
macro is written. This changes the asm-ggeneric implementation to use
a similar construct with a compound expression instead of a typecast,
which causes the compiler to not complain about an unused result.

Fix the other macros in this file in a similar way, and place them
just below their function implementations.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2015-10-15 00:21:13 +02:00
..
bitops move count_zeroes.h out of asm-generic 2015-10-15 00:21:07 +02:00
4level-fixup.h mm, asm-generic: define PUD_SHIFT in <asm-generic/4level-fixup.h> 2015-02-11 17:06:03 -08:00
asm-offsets.h asm-generic: Add common asm-offsets.h 2015-06-23 13:35:49 +09:00
atomic64.h atomic: Provide atomic_{or,xor,and} 2015-07-27 14:06:24 +02:00
atomic-long.h locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t' 2015-08-12 11:59:01 +02:00
atomic.h atomic: Collapse all atomic_{set,clear}_mask definitions 2015-07-27 14:06:24 +02:00
audit_change_attr.h audit: Modify a set of system calls in audit class definitions 2014-01-17 17:01:46 -05:00
audit_dir_write.h
audit_read.h
audit_signal.h
audit_write.h audit: Modify a set of system calls in audit class definitions 2014-01-17 17:01:46 -05:00
barrier.h locking, arch: use WRITE_ONCE()/READ_ONCE() in smp_store_release()/smp_load_acquire() 2015-08-03 10:59:30 +02:00
bitops.h arch: Prepare for smp_mb__{before,after}_atomic() 2014-04-18 11:40:30 +02:00
bitsperlong.h
bug.h bug: Make BUG() always stop the machine 2014-04-07 16:36:10 -07:00
bugs.h
cache.h
cacheflush.h
checksum.h
clkdev.h asm-generic: COMMON_CLK defines __clk_{get,put} 2014-09-25 18:00:45 -07:00
cmpxchg-local.h LLVMLinux: Remove warning about returning an uninitialized variable 2014-04-09 13:44:35 -07:00
cmpxchg.h asm-generic: cmpxchg: avoid warnings from macro-ized cmpxchg() implementations 2015-10-15 00:21:13 +02:00
cputime_jiffies.h sched, time: Fix build error with 64 bit cputime_t on 32 bit systems 2014-10-03 05:46:55 +02:00
cputime_nsecs.h sched, time: Fix build error with 64 bit cputime_t on 32 bit systems 2014-10-03 05:46:55 +02:00
cputime.h
current.h
delay.h
device.h
div64.h
dma-coherent.h DMA-API: Change dma_declare_coherent_memory() CPU address to phys_addr_t 2014-05-20 16:55:23 -06:00
dma-contiguous.h asm-generic: Add dma-contiguous.h 2014-09-22 13:35:51 +02:00
dma-mapping-broken.h
dma-mapping-common.h dma-mapping: consolidate dma_set_mask 2015-09-10 13:29:01 -07:00
dma.h
early_ioremap.h Merge branch 'akpm' (patches from Andrew) 2015-09-08 17:52:23 -07:00
emergency-restart.h
exec.h
fb.h
fixmap.h mm: provide early_memremap_ro to establish read-only mapping 2015-08-20 12:24:22 +01:00
ftrace.h
futex.h sched/preempt, futex: Disable preemption in UP futex_atomic_cmpxchg_inatomic() explicitly 2015-05-19 08:39:16 +02:00
getorder.h
gpio.h gpio: remove gpiod_sysfs_set_active_low 2015-05-12 10:46:53 +02:00
hardirq.h
hugetlb.h mm: Fix generic hugetlb pte check return type. 2013-10-02 20:02:35 -04:00
hw_irq.h
ide_iops.h
int-ll64.h
io.h x86/mm, asm-generic: Add IOMMU ioremap_uc() variant default 2015-07-21 10:47:03 +02:00
ioctl.h include/asm-generic/ioctl.h: fix _IOC_TYPECHECK sparse error 2014-06-06 16:08:13 -07:00
iomap.h x86/mm, asm-generic: Add ioremap_wt() for creating Write-Through mappings 2015-06-07 15:28:56 +02:00
irq_regs.h
irq_work.h irq_work: Introduce arch_irq_work_has_interrupt() 2014-09-13 18:38:07 +02:00
irq.h
irqflags.h
Kbuild.asm
kdebug.h
kmap_types.h
kvm_para.h KVM: add kvm_para_available to asm-generic/kvm_para.h 2013-06-05 13:21:29 +03:00
libata-portmap.h
linkage.h
local64.h
local.h
mcs_spinlock.h locking/mcs: Allow architecture specific asm files to be used for contended case 2014-02-09 21:18:52 +01:00
memory_model.h mm: fix type cast in __pfn_to_phys() 2015-09-19 03:58:10 -04:00
mm_hooks.h mm: Make arch_unmap()/bprm_mm_init() available to all architectures 2014-11-19 11:54:13 +01:00
mm-arch-hooks.h mm: clean up per architecture MM hook header files 2015-07-17 16:39:53 -07:00
mmu_context.h asm-generic: Remove asm-generic arch_bprm_mm_init() 2014-11-22 21:52:08 +01:00
mmu.h
module.h
msi.h asm-generic: Add msi.h 2014-11-23 13:01:47 +01:00
mutex-dec.h arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not 2013-06-26 12:10:55 +02:00
mutex-null.h arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not 2013-06-26 12:10:55 +02:00
mutex-xchg.h arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not 2013-06-26 12:10:55 +02:00
mutex.h
page.h
param.h
parport.h
pci_iomap.h PCI: Add pci_iomap_wc() variants 2015-08-25 09:59:45 +02:00
pci-bridge.h
pci-dma-compat.h pci-dma-compat: add pci_zalloc_consistent helper 2014-08-08 15:57:28 -07:00
pci.h PCI: Remove unused pcibios_select_root() (again) 2015-06-08 07:56:21 -05:00
percpu.h percpu: preffity percpu header files 2014-06-17 19:12:40 -04:00
pgalloc.h
pgtable-nopmd.h
pgtable-nopud.h
pgtable.h mm: clarify that the function operates on hugepage pte 2015-06-24 17:49:44 -07:00
preempt.h sched/preempt: Fix cond_resched_lock() and cond_resched_softirq() 2015-08-03 12:21:24 +02:00
ptrace.h
qrwlock_types.h locking/rwlocks: Introduce 'qrwlocks' - fair, queued rwlocks 2014-06-06 07:58:28 +02:00
qrwlock.h locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics 2015-08-12 11:59:06 +02:00
qspinlock_types.h locking/qspinlock: Optimize for smaller NR_CPUS 2015-05-08 12:36:48 +02:00
qspinlock.h locking/qspinlock/x86: Fix performance regression under unaccelerated VMs 2015-09-11 07:49:42 +02:00
resource.h asm-generic: remove _STK_LIM_MAX 2014-05-15 00:32:09 +01:00
rtc.h rtc: cmos: century support 2015-09-05 13:19:09 +02:00
rwsem.h asm-generic: rwsem: de-PPCify rwsem.h 2014-03-14 18:02:08 +00:00
seccomp.h seccomp: allow COMPAT sigreturn overrides 2015-04-17 09:04:09 -04:00
sections.h nosave: consolidate __nosave_{begin,end} in <asm/sections.h> 2014-10-09 22:26:04 -04:00
segment.h
serial.h
siginfo.h constify copy_siginfo_to_user{,32}() 2013-11-09 00:16:29 -05:00
signal.h
simd.h crypto: create generic version of ablk_helper 2013-09-24 06:02:24 +10:00
sizes.h
spinlock.h
statfs.h
string.h
switch_to.h
syscall.h syscall.h: fix doc text for syscall_get_arch() 2014-09-23 16:20:00 -04:00
syscalls.h
termios-base.h
termios.h
timex.h
tlb.h mm: mmu_gather: use tlb->end != 0 only for TLB invalidation 2015-01-13 15:20:40 +13:00
tlbflush.h
topology.h
trace_clock.h
uaccess-unaligned.h
uaccess.h asm-generic: uaccess: Spelling s/a ny/any/ 2014-01-02 10:45:23 +01:00
unaligned.h asm-generic: allow generic unaligned access if the arch supports it 2014-05-08 10:22:23 +02:00
unistd.h We get rid of the general module prefix confusion with a binary config option, 2013-05-05 10:58:06 -07:00
user.h
vga.h
vmlinux.lds.h kbuild: Fix .text.unlikely placement 2015-08-20 14:55:54 +02:00
vtime.h include/asm-generic/vtime.h: avoid zero-length file 2013-09-30 14:31:02 -07:00
word-at-a-time.h Make asm/word-at-a-time.h available on all architectures 2015-07-08 16:41:55 -04:00
xor.h