linux/drivers/firmware
Sylvain Chouleur 21b3ddd39f efi: Don't use spinlocks for efi vars
All efivars operations are protected by a spinlock which prevents
interruptions and preemption. This is too restricted, we just need a
lock preventing concurrency.
The idea is to use a semaphore of count 1 and to have two ways of
locking, depending on the context:
- In interrupt context, we call down_trylock(), if it fails we return
  an error
- In normal context, we call down_interruptible()

We don't use a mutex here because the mutex_trylock() function must not
be called from interrupt context, whereas the down_trylock() can.

Signed-off-by: Sylvain Chouleur <sylvain.chouleur@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09 16:08:42 +01:00
..
broadcom
efi efi: Don't use spinlocks for efi vars 2016-09-09 16:08:42 +01:00
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arm_scpi.c
dcdbas.c
dcdbas.h
dell_rbu.c
dmi-id.c
dmi-sysfs.c
dmi_scan.c
edd.c
iscsi_ibft.c
iscsi_ibft_find.c
Kconfig
Makefile
memmap.c
pcdp.c
pcdp.h
psci.c
qcom_scm-32.c
qcom_scm-64.c
qcom_scm.c
qcom_scm.h
qemu_fw_cfg.c
raspberrypi.c
scpi_pm_domain.c