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494fc42170
linux/arch/sparc/kernel
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Christoph Lameter 494fc42170 sparc: Replace __get_cpu_var uses 
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Cc: sparclinux@vger.kernel.org
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-26 13:45:55 -04:00
..
.gitignore
apc.c sparc idle: rename pm_idle to sparc_idle 2013-02-17 23:36:56 -05:00
asm-offsets.c [PATCH] sparc32: vm_area_struct access for old Sun SPARCs. 2013-07-10 13:56:10 -07:00
audit.c sparc64: fix sparse warnings in compat_audit.c 2014-05-18 19:01:34 -07:00
auxio_32.c sparc32: fix sparse warning in auxio_32.c 2014-05-18 19:01:27 -07:00
auxio_64.c sparc: remove __devinit, __devexit annotations 2013-01-12 15:28:45 -08:00
btext.c sparc64: fix sparse warning in btext.c 2014-05-18 19:01:30 -07:00
central.c sparc: remove __devinit, __devexit annotations 2013-01-12 15:28:45 -08:00
cherrs.S
chmc.c sparc: remove __devinit, __devexit annotations 2013-01-12 15:28:45 -08:00
compat_audit.c sparc64: fix sparse warnings in compat_audit.c 2014-05-18 19:01:34 -07:00
cpu.c sparc: fix sparse warnings in cpu.c 2014-04-29 01:12:25 -04:00
cpumap.c sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
cpumap.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
devices.c sparc32: drop tadpole specific code 2014-05-18 19:01:29 -07:00
dma.c sparc: remove several unnecessary module.h include instances 2011-10-31 19:30:54 -04:00
ds.c sparc: fix ldom_reboot buffer overflow harder 2013-10-02 20:01:56 -04:00
dtlb_miss.S
dtlb_prot.S
ebus.c sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
entry.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
entry.S sparc32: Fix exit flag passed from traced sys_sigreturn 2013-07-31 19:10:04 -07:00
etrap_32.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00
etrap_64.S sparc64: clear syscall_noerror on the entry to syscall, not on the exit 2012-10-14 19:26:52 -04:00
fpu_traps.S
ftrace.c ftrace: Do not pass data to ftrace_dyn_arch_init 2014-03-07 10:06:14 -05:00
getsetcc.S
head_32.S sparc32: drop swapper_pg_dir 2012-07-26 16:46:15 -07:00
head_64.S sparc64: Use 'ILOG2_4MB' instead of constant '22'. 2014-05-03 22:52:50 -07:00
helpers.S
hvapi.c sparc: fix format string argument for prom_printf() 2012-10-02 23:20:34 -04:00
hvcalls.S sparc64: Add hypervisor interfaces for SPARC-T4 perf counter access. 2012-08-18 23:03:53 -07:00
hvtramp.S sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
idprom.c sparc: Clear out unused asm/machines.h values. 2012-05-11 20:45:18 -07:00
iommu_common.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
iommu.c sparc64: fix sparse warning in pci.c 2014-05-18 19:01:31 -07:00
ioport.c sparc32: fix sparse warnings in ioport.c 2014-04-29 01:12:25 -04:00
irq_32.c sparc32: fix sparse warnings in irq_32.c 2014-04-29 01:12:25 -04:00
irq_64.c irq: Consolidate do_softirq() arch overriden implementations 2013-10-01 12:53:25 +02:00
irq.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
itlb_miss.S
ivec.S
jump_label.c sparc: Fix even more fallout from system.h split. 2012-03-29 22:40:52 -07:00
kernel.h sparc64: fix sparse warning in kgdb_64.c 2014-05-18 19:01:34 -07:00
kgdb_32.c sparc: explicitly include sched.h to get task_thread_info declaration 2013-02-06 11:04:10 -08:00
kgdb_64.c sparc64: fix sparse warning in kgdb_64.c 2014-05-18 19:01:34 -07:00
kprobes.c sparc: Replace __get_cpu_var uses 2014-08-26 13:45:55 -04:00
kstack.h
ktlb.S sparc64: Use 'ILOG2_4MB' instead of constant '22'. 2014-05-03 22:52:50 -07:00
ldc.c sparc64: ldc_connect() should not return EINVAL when handshake is in progress. 2014-08-04 20:18:17 -07:00
led.c
leon_kernel.c sparc32: fix sparse warnings in time_32.c 2014-05-18 19:01:27 -07:00
leon_pci_grpci1.c sparc32: replace flip_dword() with swab32() 2014-05-02 01:30:21 -04:00
leon_pci_grpci2.c sparc32: replace flip_dword() with swab32() 2014-05-02 01:30:21 -04:00
leon_pci.c sparc32: introduce asm-generic/io.h 2014-05-02 01:30:21 -04:00
leon_pmc.c sparc32: fix sparse warnings in leon_pmc.c 2014-04-29 01:12:27 -04:00
leon_smp.c sparc: Replace __get_cpu_var uses 2014-08-26 13:45:55 -04:00
Makefile sparc32: drop tadpole specific code 2014-05-18 19:01:29 -07:00
mdesc.c sparc: Add support for seek and shorter read to /dev/mdesc 2014-07-21 21:37:06 -07:00
misctrap.S
module.c mm/arch: use NUMA_NO_NODE 2013-11-13 12:09:05 +09:00
nmi.c sparc: Replace __get_cpu_var uses 2014-08-26 13:45:55 -04:00
of_device_32.c sparc32: rename sparc_irq_config to sparc_config 2012-04-15 10:28:49 -07:00
of_device_64.c devicetree: add helper inline for retrieving a node's full name 2012-07-06 07:16:34 -05:00
of_device_common.c sparc: fix sparse warnings in of_device_common.c 2014-04-29 01:12:27 -04:00
of_device_common.h
pci_common.c sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
pci_fire.c sparc: remove __devinit, __devexit annotations 2013-01-12 15:28:45 -08:00
pci_impl.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
pci_msi.c sparc: convert old cpumask API into new one 2011-05-16 13:38:07 -07:00
pci_psycho.c sparc: remove __devinit, __devexit annotations 2013-01-12 15:28:45 -08:00
pci_sabre.c sparc: remove __devinit, __devexit annotations 2013-01-12 15:28:45 -08:00
pci_schizo.c sparc: remove __devinit, __devexit annotations 2013-01-12 15:28:45 -08:00
pci_sun4v_asm.S
pci_sun4v.c sparc: Replace __get_cpu_var uses 2014-08-26 13:45:55 -04:00
pci_sun4v.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
pci.c sparc64: Properly claim resources as each PCI bus is probed. 2014-08-13 21:17:49 -07:00
pcic.c sparc32: fix sparse warnings in pcic.c 2014-05-18 19:01:27 -07:00
pcr.c sparc64: Add PCR ops for SPARC-T4. 2012-08-18 23:26:19 -07:00
perf_event.c sparc: Replace __get_cpu_var uses 2014-08-26 13:45:55 -04:00
pmc.c sparc idle: rename pm_idle to sparc_idle 2013-02-17 23:36:56 -05:00
power.c sparc: remove __devinit, __devexit annotations 2013-01-12 15:28:45 -08:00
process_32.c sparc32: fix sparse warning in auxio_32.c 2014-05-18 19:01:27 -07:00
process_64.c sparc64: Fix pcr_ops initialization and usage bugs. 2014-08-11 20:45:12 -07:00
prom_32.c sparc: remove several unnecessary module.h include instances 2011-10-31 19:30:54 -04:00
prom_64.c sparc64: fix sparse warning in prom_64.c 2014-05-18 19:01:31 -07:00
prom_common.c of: Fix locking vs. interrupts 2013-06-13 22:12:14 +01:00
prom_irqtrans.c sparc: Remove unnecessary semicolons 2011-06-07 16:06:34 -07:00
prom.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
psycho_common.c sparc: Remove unnecessary semicolons 2011-06-07 16:06:34 -07:00
psycho_common.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
ptrace_32.c sparc32: fix sparse warning in ptrace_32.c 2014-04-29 01:12:26 -04:00
ptrace_64.c sparc64: Implement HAVE_CONTEXT_TRACKING 2013-11-14 14:57:21 -08:00
reboot.c Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
rtrap_32.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00
rtrap_64.S Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
sbus.c sparc: kernel/sbus.c: fix memory leakage 2013-01-21 14:33:00 -08:00
setup_32.c sparc32: fix sparse warnings in setup_32.c 2014-04-29 01:12:25 -04:00
setup_64.c cpu hw caps support for sparc64x 2013-07-31 19:10:03 -07:00
signal32.c sparc64: clean up compat_sigset_t.seta handling 2014-05-18 19:01:32 -07:00
signal_32.c sparc32: fix sparse warnings in signal_32.c 2014-04-29 01:12:25 -04:00
signal_64.c sparc64: fix sparse "Should it be static?" warnings in signal32.c 2014-05-18 19:01:32 -07:00
sigutil_32.c Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
sigutil_64.c Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
sigutil.h sparc: Allow handling signals when stack is corrupted. 2011-08-20 17:14:54 -07:00
smp_32.c sparc: fix decimal printf format specifiers prefixed with 0x 2014-08-06 14:41:10 -07:00
smp_64.c sparc64: Fix pcr_ops initialization and usage bugs. 2014-08-11 20:45:12 -07:00
sparc_ksyms_32.c sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
sparc_ksyms_64.c sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
spiterrs.S
sstate.c sparc: Set reboot-cmd using reboot data hypervisor call if available. 2011-08-02 21:28:52 -07:00
stacktrace.c sparc: move symbol exporters to use export.h not module.h 2011-10-31 19:30:53 -04:00
starfire.c sparc: explicitly cast negative phandle checks to s32 2011-01-03 20:02:06 -07:00
sun4d_irq.c sparc32: fix sparse warnings in sun4d_irq.c 2014-04-29 01:12:25 -04:00
sun4d_smp.c sparc: Replace __get_cpu_var uses 2014-08-26 13:45:55 -04:00
sun4m_irq.c sun4M: add include of slab.h for kzalloc 2014-02-12 16:10:45 -05:00
sun4m_smp.c sparc: delete __cpuinit/__CPUINIT usage from all users 2013-07-14 19:36:52 -04:00
sun4v_ivec.S
sun4v_tlb_miss.S sparc64: Move from 4MB to 8MB huge pages. 2013-11-12 15:22:34 -08:00
sys32.S sparc: Hook up renameat2 syscall. 2014-07-21 22:27:56 -07:00
sys_sparc32.c sparc64: fix sparse warnings in sys_sparc32.c 2014-05-18 19:01:31 -07:00
sys_sparc_32.c sparc32: fix sparse warnings in sys_sparc_32.c 2014-05-18 19:01:28 -07:00
sys_sparc_64.c sparc64: fix sparse warnings in sys_sparc_64.c + unaligned_64.c 2014-05-18 19:01:30 -07:00
syscalls.S sparc64: don't treat 64-bit syscall return codes as 32-bit 2014-03-17 15:54:52 -04:00
sysfs.c sparc64: fix format string mismatch in arch/sparc/kernel/sysfs.c 2014-05-21 12:54:42 -07:00
systbls_32.S sparc: Hook up memfd_create system call. 2014-08-13 22:00:09 -07:00
systbls_64.S sparc: Hook up memfd_create system call. 2014-08-13 22:00:09 -07:00
systbls.h sparc64: fix sparse warnings in sys_sparc32.c 2014-05-18 19:01:31 -07:00
time_32.c sparc32: fix sparse warnings in time_32.c 2014-05-18 19:01:27 -07:00
time_64.c sparc: Replace __get_cpu_var uses 2014-08-26 13:45:55 -04:00
trampoline_32.S sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
trampoline_64.S sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
traps_32.c sparc: fix sparse warning in math_{32,64} 2014-05-18 19:01:28 -07:00
traps_64.c sparc64: fix sparse warnings in sys_sparc_64.c + unaligned_64.c 2014-05-18 19:01:30 -07:00
tsb.S sparc64: Move from 4MB to 8MB huge pages. 2013-11-12 15:22:34 -08:00
ttable_32.S sparc32: move trap table to a separate file 2012-05-19 23:27:25 -07:00
ttable_64.S sparc64: renamed ttable.S to ttable_64.S 2012-05-19 23:26:41 -07:00
una_asm_32.S sparc32: unaligned memory access (MNA) trap handler bug 2011-02-01 12:39:59 -08:00
una_asm_64.S sparc: Fix .size directive for do_int_load 2011-03-16 18:19:15 -07:00
unaligned_32.c sparc: use %s for unaligned panic 2014-07-21 21:37:06 -07:00
unaligned_64.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next 2014-06-19 07:50:07 -10:00
utrap.S
vio.c sparc/kernel/vio.c: add put_device() after device_find_child() 2013-05-04 17:38:18 -07:00
viohs.c sparc: move symbol exporters to use export.h not module.h 2011-10-31 19:30:53 -04:00
visemul.c sparc64: Make montmul/montsqr/mpmul usable in 32-bit threads. 2012-10-26 15:18:37 -07:00
vmlinux.lds.S sparc64: Make PAGE_OFFSET variable. 2013-11-12 15:22:34 -08:00
windows.c sparc32: fix sparse warnings in windows.c 2014-04-29 01:12:25 -04:00
winfixup.S sparc64: Make montmul/montsqr/mpmul usable in 32-bit threads. 2012-10-26 15:18:37 -07:00
wof.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00
wuf.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00