diff options
| author |   Aniruddha Banerjee <aniruddhab@nvidia.com> | 2018-03-28 19:12:00 +0530 |
|---|---|---|
| committer |   Marc Zyngier <marc.zyngier@arm.com> | 2018-03-29 11:47:50 +0100 |
| commit | aa08192a254d362a4d5317647a81de6996961aef (patch) | |
| tree | 4078cc6883332ae0fda2dca708cd5ace43a4a354 /drivers/irqchip | |
| parent | irqchip/gic: Update supports_deactivate static key to modern api (diff) | |
| download | linux-dev-aa08192a254d362a4d5317647a81de6996961aef.tar.xz linux-dev-aa08192a254d362a4d5317647a81de6996961aef.zip | |
irqchip/gic: Take lock when updating irq type
Most MMIO GIC register accesses use a 1-hot bit scheme that
avoids requiring any form of locking. This isn't true for the
GICD_ICFGRn registers, which require a RMW sequence.
Unfortunately, we seem to be missing a lock for these particular
accesses, which could result in a race condition if changing the
trigger type on any two interrupts within the same set of 16
interrupts (and thus controlled by the same CFGR register).
Introduce a private lock in the GIC common comde for this
particular case, making it cover both GIC implementations
in one go.
Cc: stable@vger.kernel.org
Signed-off-by: Aniruddha Banerjee <aniruddhab@nvidia.com>
[maz: updated changelog]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'drivers/irqchip')
| -rw-r--r-- | drivers/irqchip/irq-gic-common.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/irqchip/irq-gic-common.c b/drivers/irqchip/irq-gic-common.c index 30017df5b54c..01e673c680cd 100644 --- a/drivers/irqchip/irq-gic-common.c +++ b/drivers/irqchip/irq-gic-common.c @@ -21,6 +21,8 @@ #include "irq-gic-common.h" +static DEFINE_RAW_SPINLOCK(irq_controller_lock); + static const struct gic_kvm_info *gic_kvm_info; const struct gic_kvm_info *gic_get_kvm_info(void) @@ -53,11 +55,13 @@ int gic_configure_irq(unsigned int irq, unsigned int type, u32 confoff = (irq / 16) * 4; u32 val, oldval; int ret = 0; + unsigned long flags; /* * Read current configuration register, and insert the config * for "irq", depending on "type". */ + raw_spin_lock_irqsave(&irq_controller_lock, flags); val = oldval = readl_relaxed(base + GIC_DIST_CONFIG + confoff); if (type & IRQ_TYPE_LEVEL_MASK) val &= ~confmask; @@ -65,8 +69,10 @@ int gic_configure_irq(unsigned int irq, unsigned int type, val |= confmask; /* If the current configuration is the same, then we are done */ - if (val == oldval) + if (val == oldval) { + raw_spin_unlock_irqrestore(&irq_controller_lock, flags); return 0; + } /* * Write back the new configuration, and possibly re-enable @@ -84,6 +90,7 @@ int gic_configure_irq(unsigned int irq, unsigned int type, pr_warn("GIC: PPI%d is secure or misconfigured\n", irq - 16); } + raw_spin_unlock_irqrestore(&irq_controller_lock, flags); if (sync_access) sync_access(); |