Threaded interrupts can perform the function of the tasklet, and much
more safely too - without races when trying to take the tasklet and
interrupt down on device removal.
With the old code, there is a window where we call tasklet_kill(). If
the interrupt handler happens to be running on a different CPU, and
subsequently calls tasklet_schedule(), the tasklet will be re-scheduled
for execution.
Switching to a hardirq/threadirq combination implementation avoids this,
and it also means generic code deals with the teardown sequencing of the
threaded and non-threaded parts.
Signed-off-by: Russell King <rmk+ker...@arm.linux.org.uk>
---
drivers/crypto/caam/intern.h | 1 -
drivers/crypto/caam/jr.c | 25 +++++++++----------------
2 files changed, 9 insertions(+), 17 deletions(-)
diff --git a/drivers/crypto/caam/intern.h b/drivers/crypto/caam/intern.h
index e2bcacc1a921..5d4c05074a5c 100644
--- a/drivers/crypto/caam/intern.h
+++ b/drivers/crypto/caam/intern.h
@@ -41,7 +41,6 @@ struct caam_drv_private_jr {
struct device *dev;
int ridx;
struct caam_job_ring __iomem *rregs; /* JobR's register space */
- struct tasklet_struct irqtask;
int irq; /* One per queue */
/* Number of scatterlist crypt transforms active on the JobR */
diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c
index f7e0d8d4c3da..b77ee2b88f37 100644
--- a/drivers/crypto/caam/jr.c
+++ b/drivers/crypto/caam/jr.c
@@ -73,8 +73,6 @@ int caam_jr_shutdown(struct device *dev)
ret = caam_reset_hw_jr(dev);
- tasklet_kill(&jrp->irqtask);
-
/* Release interrupt */
free_irq(jrp->irq, dev);
@@ -130,7 +128,7 @@ static irqreturn_t caam_jr_interrupt(int irq, void *st_dev)
/*
* Check the output ring for ready responses, kick
- * tasklet if jobs done.
+ * the threaded irq if jobs done.
*/
irqstate = rd_reg32(&jrp->rregs->jrintstatus);
if (!irqstate)
@@ -152,18 +150,13 @@ static irqreturn_t caam_jr_interrupt(int irq, void
*st_dev)
/* Have valid interrupt at this point, just ACK and trigger */
wr_reg32(&jrp->rregs->jrintstatus, irqstate);
- preempt_disable();
- tasklet_schedule(&jrp->irqtask);
- preempt_enable();
-
- return IRQ_HANDLED;
+ return IRQ_WAKE_THREAD;
}
-/* Deferred service handler, run as interrupt-fired tasklet */
-static void caam_jr_dequeue(unsigned long devarg)
+static irqreturn_t caam_jr_threadirq(int irq, void *st_dev)
{
int hw_idx, sw_idx, i, head, tail;
- struct device *dev = (struct device *)devarg;
+ struct device *dev = st_dev;
struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
void (*usercall)(struct device *dev, u32 *desc, u32 status, void *arg);
u32 *userdesc, userstatus;
@@ -237,6 +230,8 @@ static void caam_jr_dequeue(unsigned long devarg)
/* reenable / unmask IRQs */
clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
+
+ return IRQ_HANDLED;
}
/**
@@ -394,11 +389,10 @@ static int caam_jr_init(struct device *dev)
jrp = dev_get_drvdata(dev);
- tasklet_init(&jrp->irqtask, caam_jr_dequeue, (unsigned long)dev);
-
/* Connect job ring interrupt handler. */
- error = request_irq(jrp->irq, caam_jr_interrupt, IRQF_SHARED,
- dev_name(dev), dev);
+ error = request_threaded_irq(jrp->irq, caam_jr_interrupt,
+ caam_jr_threadirq, IRQF_SHARED,
+ dev_name(dev), dev);
if (error) {
dev_err(dev, "can't connect JobR %d interrupt (%d)\n",
jrp->ridx, jrp->irq);
@@ -460,7 +454,6 @@ static int caam_jr_init(struct device *dev)
out_free_irq:
free_irq(jrp->irq, dev);
out_kill_deq:
- tasklet_kill(&jrp->irqtask);
return error;
}
--
2.1.0
--
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