linux/arch
Dave Martin 7fe31d28e8 ARM: mcpm: introduce helpers for platform coherency exit/setup
This provides helper methods to coordinate between CPUs coming down
and CPUs going up, as well as documentation on the used algorithms,
so that cluster teardown and setup
operations are not done for a cluster simultaneously.

For use in the power_down() implementation:
  * __mcpm_cpu_going_down(unsigned int cluster, unsigned int cpu)
  * __mcpm_outbound_enter_critical(unsigned int cluster)
  * __mcpm_outbound_leave_critical(unsigned int cluster)
  * __mcpm_cpu_down(unsigned int cluster, unsigned int cpu)

The power_up_setup() helper should do platform-specific setup in
preparation for turning the CPU on, such as invalidating local caches
or entering coherency.  It must be assembler for now, since it must
run before the MMU can be switched on.  It is passed the affinity level
for which initialization should be performed.

Because the mcpm_sync_struct content is looked-up and modified
with the cache enabled or disabled depending on the code path, it is
crucial to always ensure proper cache maintenance to update main memory
right away.  The sync_cache_*() helpers are used to that end.

Also, in order to prevent a cached writer from interfering with an
adjacent non-cached writer, we ensure each state variable is located to
a separate cache line.

Thanks to Nicolas Pitre and Achin Gupta for the help with this
patch.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
2013-04-24 10:37:00 -04:00
..
alpha Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
arc ARC: split elf.h into uapi and export it for userspace 2013-02-27 20:00:26 +05:30
arm ARM: mcpm: introduce helpers for platform coherency exit/setup 2013-04-24 10:37:00 -04:00
arm64 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-03-02 08:34:06 -08:00
avr32 Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
blackfin Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
c6x Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
cris Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
frv Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
h8300 Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
hexagon Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
ia64 Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
m32r UAPI: fix endianness conditionals in M32R's asm/stat.h 2013-03-13 15:21:49 -07:00
m68k Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
metag metag: Inhibit NUMA balancing. 2013-03-04 10:29:19 +00:00
microblaze Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
mips Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
mn10300 Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
openrisc openrisc: remove HAVE_VIRT_TO_BUS 2013-03-13 06:12:39 +01:00
parisc Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
powerpc Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
s390 Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
score Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
sh hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
sparc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-03-02 08:34:06 -08:00
tile Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
um um: Use tty_port in SIGWINCH handler 2013-03-11 10:08:04 +01:00
unicore32 Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
x86 perf,x86: fix wrmsr_on_cpu() warning on suspend/resume 2013-03-17 15:44:43 -07:00
xtensa Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
.gitignore
Kconfig Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00