Patchwork [24/37] powerpc: return early if irq_host lookup type is wrong

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Submitter Milton Miller
Date May 11, 2011, 5:29 a.m.
Message ID <a254a95c4fe502cf11a3a094afe0298263c3dbd6.1305092637.git.miltonm@bga.com>
Download mbox | patch
Permalink /patch/95090/
State Accepted, archived
Commit 2d441681a4df7822e6ef6fcc0320bb14d2a06dbb
Delegated to: Benjamin Herrenschmidt
Headers show

Comments

Milton Miller - May 11, 2011, 5:29 a.m.
If for some reason the code incrorectly calls the wrong function to
manage the revmap, not only should we warn, we should take action.
However, in the paths we expect to be taken every delivered interrupt
change to WARN_ON_ONCE.  Use the if (WARN_ON(x)) format to get the
unlikely for free.

Signed-off-by: Milton Miller <miltonm@bga.com>
---
 arch/powerpc/kernel/irq.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)
Grant Likely - May 11, 2011, 7:03 p.m.
On Wed, May 11, 2011 at 7:29 AM, Milton Miller <miltonm@bga.com> wrote:
> If for some reason the code incrorectly calls the wrong function to
> manage the revmap, not only should we warn, we should take action.
> However, in the paths we expect to be taken every delivered interrupt
> change to WARN_ON_ONCE.  Use the if (WARN_ON(x)) format to get the
> unlikely for free.
>
> Signed-off-by: Milton Miller <miltonm@bga.com>

Looks right.

Reviewed-by: Grant Likely <grant.likely@secretlab.ca>

> ---
>  arch/powerpc/kernel/irq.c |   12 +++++++-----
>  1 files changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
> index f42e869..4a5aa8c 100644
> --- a/arch/powerpc/kernel/irq.c
> +++ b/arch/powerpc/kernel/irq.c
> @@ -814,8 +814,7 @@ void irq_dispose_mapping(unsigned int virq)
>                return;
>
>        host = irq_map[virq].host;
> -       WARN_ON (host == NULL);
> -       if (host == NULL)
> +       if (WARN_ON(host == NULL))
>                return;
>
>        /* Never unmap legacy interrupts */
> @@ -898,7 +897,8 @@ unsigned int irq_radix_revmap_lookup(struct irq_host *host,
>        struct irq_map_entry *ptr;
>        unsigned int virq;
>
> -       WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
> +       if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_TREE))
> +               return irq_find_mapping(host, hwirq);
>
>        /*
>         * No rcu_read_lock(ing) needed, the ptr returned can't go under us
> @@ -922,7 +922,8 @@ unsigned int irq_radix_revmap_lookup(struct irq_host *host,
>  void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
>                             irq_hw_number_t hwirq)
>  {
> -       WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
> +       if (WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE))
> +               return;
>
>        if (virq != NO_IRQ) {
>                mutex_lock(&revmap_trees_mutex);
> @@ -937,7 +938,8 @@ unsigned int irq_linear_revmap(struct irq_host *host,
>  {
>        unsigned int *revmap;
>
> -       WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
> +       if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_LINEAR))
> +               return irq_find_mapping(host, hwirq);
>
>        /* Check revmap bounds */
>        if (unlikely(hwirq >= host->revmap_data.linear.size))
> --
> 1.7.0.4
>
>

Patch

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index f42e869..4a5aa8c 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -814,8 +814,7 @@  void irq_dispose_mapping(unsigned int virq)
 		return;
 
 	host = irq_map[virq].host;
-	WARN_ON (host == NULL);
-	if (host == NULL)
+	if (WARN_ON(host == NULL))
 		return;
 
 	/* Never unmap legacy interrupts */
@@ -898,7 +897,8 @@  unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 	struct irq_map_entry *ptr;
 	unsigned int virq;
 
-	WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
+	if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_TREE))
+		return irq_find_mapping(host, hwirq);
 
 	/*
 	 * No rcu_read_lock(ing) needed, the ptr returned can't go under us
@@ -922,7 +922,8 @@  unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 			     irq_hw_number_t hwirq)
 {
-	WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
+	if (WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE))
+		return;
 
 	if (virq != NO_IRQ) {
 		mutex_lock(&revmap_trees_mutex);
@@ -937,7 +938,8 @@  unsigned int irq_linear_revmap(struct irq_host *host,
 {
 	unsigned int *revmap;
 
-	WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
+	if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_LINEAR))
+		return irq_find_mapping(host, hwirq);
 
 	/* Check revmap bounds */
 	if (unlikely(hwirq >= host->revmap_data.linear.size))