[PATCH v3] s390: replace setup_irq() by request_irq()

[PATCH v3] s390: replace setup_irq() by request_irq()

[afzal mohammed]

request_irq() is preferred over setup_irq(). Invocations of setup_irq()
occur after memory allocators are ready.

Per tglx[1], setup_irq() existed in olden days when allocators were not
ready by the time early interrupts were initialized.

Hence replace setup_irq() by request_irq().

[1] https://lkml.kernel.org/r/alpine.DEB.2.20.1710191609480.1971@nanos

Signed-off-by: afzal mohammed <afzal.mohd.ma@gmail.com>
---
Hi s390 maintainers,

if okay w/ this change, please consider taking it thr' your tree, else please
let me know.

Regards
afzal

Link to v2 & v1,
[v2] https://lkml.kernel.org/r/cover.1582471508.git.afzal.mohd.ma@gmail.com
[v1] https://lkml.kernel.org/r/cover.1581478323.git.afzal.mohd.ma@gmail.com

v3:
 * Split out from tree wide series, as Thomas suggested to get it thr'
	respective maintainers
 * Modify pr_err displayed in case of error
 * Re-arrange code & choose pr_err args as required to improve readability
 * Remove irrelevant parts from commit message & improve
 
v2:
 * Replace pr_err("request_irq() on %s failed" by
           pr_err("%s: request_irq() failed"
 * Commit message massage

 arch/s390/kernel/irq.c  | 8 ++------
 drivers/s390/cio/airq.c | 8 ++------
 drivers/s390/cio/cio.c  | 8 ++------
 3 files changed, 6 insertions(+), 18 deletions(-)

diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 8371855042dc..015c9dc45f7d 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -294,11 +294,6 @@ static irqreturn_t do_ext_interrupt(int irq, void *dummy)
 	return IRQ_HANDLED;
 }
 
-static struct irqaction external_interrupt = {
-	.name	 = "EXT",
-	.handler = do_ext_interrupt,
-};
-
 void __init init_ext_interrupts(void)
 {
 	int idx;
@@ -308,7 +303,8 @@ void __init init_ext_interrupts(void)
 
 	irq_set_chip_and_handler(EXT_INTERRUPT,
 				 &dummy_irq_chip, handle_percpu_irq);
-	setup_irq(EXT_INTERRUPT, &external_interrupt);
+	if (request_irq(EXT_INTERRUPT, do_ext_interrupt, 0, "EXT", NULL))
+		pr_err("Failed to register EXT interrupt\n");
 }
 
 static DEFINE_SPINLOCK(irq_subclass_lock);
diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c
index 427b2e24a8ce..a860da77b0d1 100644
--- a/drivers/s390/cio/airq.c
+++ b/drivers/s390/cio/airq.c
@@ -105,16 +105,12 @@ static irqreturn_t do_airq_interrupt(int irq, void *dummy)
 	return IRQ_HANDLED;
 }
 
-static struct irqaction airq_interrupt = {
-	.name	 = "AIO",
-	.handler = do_airq_interrupt,
-};
-
 void __init init_airq_interrupts(void)
 {
 	irq_set_chip_and_handler(THIN_INTERRUPT,
 				 &dummy_irq_chip, handle_percpu_irq);
-	setup_irq(THIN_INTERRUPT, &airq_interrupt);
+	if (request_irq(THIN_INTERRUPT, do_airq_interrupt, 0, "AIO", NULL))
+		pr_err("Failed to register AIO interrupt\n");
 }
 
 static inline unsigned long iv_size(unsigned long bits)
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 18f5458f90e8..94a66d6d32a3 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -563,16 +563,12 @@ static irqreturn_t do_cio_interrupt(int irq, void *dummy)
 	return IRQ_HANDLED;
 }
 
-static struct irqaction io_interrupt = {
-	.name	 = "I/O",
-	.handler = do_cio_interrupt,
-};
-
 void __init init_cio_interrupts(void)
 {
 	irq_set_chip_and_handler(IO_INTERRUPT,
 				 &dummy_irq_chip, handle_percpu_irq);
-	setup_irq(IO_INTERRUPT, &io_interrupt);
+	if (request_irq(IO_INTERRUPT, do_cio_interrupt, 0, "I/O", NULL))
+		pr_err("Failed to register I/O interrupt\n");
 }
 
 #ifdef CONFIG_CCW_CONSOLE
-- 
2.25.1

Re: [PATCH v3] s390: replace setup_irq() by request_irq()

[Heiko Carstens]

On Wed, Mar 04, 2020 at 06:20:48AM +0530, afzal mohammed wrote:
> request_irq() is preferred over setup_irq(). Invocations of setup_irq()
> occur after memory allocators are ready.
> 
> Per tglx[1], setup_irq() existed in olden days when allocators were not
> ready by the time early interrupts were initialized.
> 
> Hence replace setup_irq() by request_irq().
> 
> [1] https://lkml.kernel.org/r/alpine.DEB.2.20.1710191609480.1971@nanos
> 
> Signed-off-by: afzal mohammed <afzal.mohd.ma@gmail.com>
> ---
> Hi s390 maintainers,
> 
> if okay w/ this change, please consider taking it thr' your tree, else please
> let me know.
> 
> Regards
> afzal

Applied. However I changed the pr_err invocations to panic, since it
doesn't make sense to continue if interrupt registration fails that
early.