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authorRussell King <rmk+kernel@arm.linux.org.uk>2016-08-08 20:05:24 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2016-08-09 13:47:28 +0300
commit66d2e2028091a074aa1290d2eeda5ddb1a6c329c (patch)
treea5decf16bd35101d031defcce9f9c095649c4e33 /drivers/crypto
parent65cf164a4afab86b9d26c063bc4cef5432b52021 (diff)
downloadlinux-66d2e2028091a074aa1290d2eeda5ddb1a6c329c.tar.xz
crypto: caam - get rid of tasklet
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+kernel@arm.linux.org.uk> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto')
-rw-r--r--drivers/crypto/caam/intern.h1
-rw-r--r--drivers/crypto/caam/jr.c25
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 a81f551ac222..320228875e9a 100644
--- a/drivers/crypto/caam/jr.c
+++ b/drivers/crypto/caam/jr.c
@@ -73,8 +73,6 @@ static 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 */
clrsetbits_32(&jrp->rregs->rconfig_lo, JRCFG_IMSK, 0);
+
+ 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 @@ out_free_inpring:
out_free_irq:
free_irq(jrp->irq, dev);
out_kill_deq:
- tasklet_kill(&jrp->irqtask);
return error;
}