aboutsummaryrefslogtreecommitdiffstats
path: root/net/sched
diff options
context:
space:
mode:
authorStephen Boyd <sboyd@codeaurora.org>2012-02-07 19:42:07 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-02-29 16:33:43 -0800
commitad15d5c6dc9f1272fe1dde3de87ab775f65a6d77 (patch)
tree23ff212d98ce749f34640c85bc03cf7d73f61ce4 /net/sched
parent2efb4f6b48f54918213f0b8c3f7135aca328f8f3 (diff)
downloadkernel_samsung_smdk4412-ad15d5c6dc9f1272fe1dde3de87ab775f65a6d77.zip
kernel_samsung_smdk4412-ad15d5c6dc9f1272fe1dde3de87ab775f65a6d77.tar.gz
kernel_samsung_smdk4412-ad15d5c6dc9f1272fe1dde3de87ab775f65a6d77.tar.bz2
ARM: 7321/1: cache-v7: Disable preemption when reading CCSIDR
commit b46c0f74657d1fe1c1b0c1452631cc38a9e6987f upstream. armv7's flush_cache_all() flushes caches via set/way. To determine the cache attributes (line size, number of sets, etc.) the assembly first writes the CSSELR register to select a cache level and then reads the CCSIDR register. The CSSELR register is banked per-cpu and is used to determine which cache level CCSIDR reads. If the task is migrated between when the CSSELR is written and the CCSIDR is read the CCSIDR value may be for an unexpected cache level (for example L1 instead of L2) and incorrect cache flushing could occur. Disable interrupts across the write and read so that the correct cache attributes are read and used for the cache flushing routine. We disable interrupts instead of disabling preemption because the critical section is only 3 instructions and we want to call v7_dcache_flush_all from __v7_setup which doesn't have a full kernel stack with a struct thread_info. This fixes a problem we see in scm_call() when flush_cache_all() is called from preemptible context and sometimes the L2 cache is not properly flushed out. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/sched')
0 files changed, 0 insertions, 0 deletions