Home
last modified time | relevance | path

Searched hist:"54 f529a6" (Results 1 – 1 of 1) sorted by relevance

/openbmc/linux/drivers/firmware/
H A Darm_sdei.c54f529a6 Fri Feb 21 10:35:08 CST 2020 James Morse <james.morse@arm.com> firmware: arm_sdei: Use cpus_read_lock() to avoid races with cpuhp

SDEI has private events that need registering and enabling on each CPU.
CPUs can come and go while we are trying to do this. SDEI tries to avoid
these problems by setting the reregister flag before the register call,
so any CPUs that come online register the event too. Sticking plaster
like this doesn't work, as if the register call fails, a CPU that
subsequently comes online will register the event before reregister
is cleared.

Take cpus_read_lock() around the register and enable calls. We don't
want surprise CPUs to do the wrong thing if they race with these calls
failing.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
54f529a6 Fri Feb 21 10:35:08 CST 2020 James Morse <james.morse@arm.com> firmware: arm_sdei: Use cpus_read_lock() to avoid races with cpuhp

SDEI has private events that need registering and enabling on each CPU.
CPUs can come and go while we are trying to do this. SDEI tries to avoid
these problems by setting the reregister flag before the register call,
so any CPUs that come online register the event too. Sticking plaster
like this doesn't work, as if the register call fails, a CPU that
subsequently comes online will register the event before reregister
is cleared.

Take cpus_read_lock() around the register and enable calls. We don't
want surprise CPUs to do the wrong thing if they race with these calls
failing.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>