* [PATCH] irq_work: improve the flag definitions
@ 2017-08-14 11:56 Bartosz Golaszewski
2017-08-14 12:19 ` Andy Shevchenko
2017-08-15 9:12 ` Bartosz Golaszewski
0 siblings, 2 replies; 5+ messages in thread
From: Bartosz Golaszewski @ 2017-08-14 11:56 UTC (permalink / raw)
To: Thomas Gleixner, Marc Zyngier; +Cc: linux-kernel, Bartosz Golaszewski
IRQ_WORK_FLAGS is defined simply to 3UL. This is confusing as it
says nothing about its purpose. Define IRQ_WORK_FLAGS as a bitwise
OR of IRQ_WORK_PENDING and IRQ_WORK_BUSY.
While we're at it: use the BIT() macro for all flags.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
include/linux/irq_work.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index 47b9ebd4a74f..467a58e7e0da 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -12,10 +12,10 @@
* busy NULL, 2 -> {free, claimed} : callback in progress, can be claimed
*/
-#define IRQ_WORK_PENDING 1UL
-#define IRQ_WORK_BUSY 2UL
-#define IRQ_WORK_FLAGS 3UL
-#define IRQ_WORK_LAZY 4UL /* Doesn't want IPI, wait for tick */
+#define IRQ_WORK_PENDING BIT(0)
+#define IRQ_WORK_BUSY BIT(1)
+#define IRQ_WORK_FLAGS (IRQ_WORK_PENDING | IRQ_WORK_BUSY)
+#define IRQ_WORK_LAZY BIT(3) /* Doesn't want IPI, wait for tick */
struct irq_work {
unsigned long flags;
--
2.13.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] irq_work: improve the flag definitions
2017-08-14 11:56 [PATCH] irq_work: improve the flag definitions Bartosz Golaszewski
@ 2017-08-14 12:19 ` Andy Shevchenko
2017-08-14 17:12 ` Bartosz Golaszewski
2017-08-15 9:12 ` Bartosz Golaszewski
1 sibling, 1 reply; 5+ messages in thread
From: Andy Shevchenko @ 2017-08-14 12:19 UTC (permalink / raw)
To: Bartosz Golaszewski; +Cc: Thomas Gleixner, Marc Zyngier, linux-kernel
On Mon, Aug 14, 2017 at 2:56 PM, Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> IRQ_WORK_FLAGS is defined simply to 3UL. This is confusing as it
> says nothing about its purpose. Define IRQ_WORK_FLAGS as a bitwise
> OR of IRQ_WORK_PENDING and IRQ_WORK_BUSY.
>
> While we're at it: use the BIT() macro for all flags.
> +#define IRQ_WORK_PENDING BIT(0)
> +#define IRQ_WORK_BUSY BIT(1)
> +#define IRQ_WORK_FLAGS (IRQ_WORK_PENDING | IRQ_WORK_BUSY)
I dunno which style is preferred, though I would go with simple
GENMASK() here, as all definitions right on left :-)
Parameters of GENMASK will show last-first entries and can be easily decoded.
Although there are only two for now.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] irq_work: improve the flag definitions
2017-08-14 12:19 ` Andy Shevchenko
@ 2017-08-14 17:12 ` Bartosz Golaszewski
0 siblings, 0 replies; 5+ messages in thread
From: Bartosz Golaszewski @ 2017-08-14 17:12 UTC (permalink / raw)
To: Andy Shevchenko; +Cc: Thomas Gleixner, Marc Zyngier, linux-kernel
2017-08-14 14:19 GMT+02:00 Andy Shevchenko <andy.shevchenko@gmail.com>:
> On Mon, Aug 14, 2017 at 2:56 PM, Bartosz Golaszewski <brgl@bgdev.pl> wrote:
>> IRQ_WORK_FLAGS is defined simply to 3UL. This is confusing as it
>> says nothing about its purpose. Define IRQ_WORK_FLAGS as a bitwise
>> OR of IRQ_WORK_PENDING and IRQ_WORK_BUSY.
>>
>> While we're at it: use the BIT() macro for all flags.
>
>> +#define IRQ_WORK_PENDING BIT(0)
>> +#define IRQ_WORK_BUSY BIT(1)
>> +#define IRQ_WORK_FLAGS (IRQ_WORK_PENDING | IRQ_WORK_BUSY)
>
> I dunno which style is preferred, though I would go with simple
> GENMASK() here, as all definitions right on left :-)
>
> Parameters of GENMASK will show last-first entries and can be easily decoded.
> Although there are only two for now.
>
Which is a good enough reason to not over-complicate things and just
use an easy to decipher bitwise OR. ;)
Thanks,
Bartosz
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] irq_work: improve the flag definitions
2017-08-14 11:56 [PATCH] irq_work: improve the flag definitions Bartosz Golaszewski
2017-08-14 12:19 ` Andy Shevchenko
@ 2017-08-15 9:12 ` Bartosz Golaszewski
1 sibling, 0 replies; 5+ messages in thread
From: Bartosz Golaszewski @ 2017-08-15 9:12 UTC (permalink / raw)
To: Thomas Gleixner, Marc Zyngier; +Cc: linux-kernel, Bartosz Golaszewski
2017-08-14 13:56 GMT+02:00 Bartosz Golaszewski <brgl@bgdev.pl>:
> IRQ_WORK_FLAGS is defined simply to 3UL. This is confusing as it
> says nothing about its purpose. Define IRQ_WORK_FLAGS as a bitwise
> OR of IRQ_WORK_PENDING and IRQ_WORK_BUSY.
>
> While we're at it: use the BIT() macro for all flags.
>
> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
> ---
> include/linux/irq_work.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
> index 47b9ebd4a74f..467a58e7e0da 100644
> --- a/include/linux/irq_work.h
> +++ b/include/linux/irq_work.h
> @@ -12,10 +12,10 @@
> * busy NULL, 2 -> {free, claimed} : callback in progress, can be claimed
> */
>
> -#define IRQ_WORK_PENDING 1UL
> -#define IRQ_WORK_BUSY 2UL
> -#define IRQ_WORK_FLAGS 3UL
> -#define IRQ_WORK_LAZY 4UL /* Doesn't want IPI, wait for tick */
> +#define IRQ_WORK_PENDING BIT(0)
> +#define IRQ_WORK_BUSY BIT(1)
> +#define IRQ_WORK_FLAGS (IRQ_WORK_PENDING | IRQ_WORK_BUSY)
> +#define IRQ_WORK_LAZY BIT(3) /* Doesn't want IPI, wait for tick */
Superseded by v2 - 4UL is BIT(2), not BIT(3).
Best regards,
Bartosz Golaszewski
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] irq_work: Improve the flag definitions
@ 2018-01-05 4:19 Frederic Weisbecker
0 siblings, 0 replies; 5+ messages in thread
From: Frederic Weisbecker @ 2018-01-05 4:19 UTC (permalink / raw)
To: Thomas Gleixner, Ingo Molnar
Cc: LKML, Bartosz Golaszewski, Peter Zijlstra, Frederic Weisbecker,
Andy Shevchenko, Marc Zyngier
From: Bartosz Golaszewski <brgl@bgdev.pl>
IRQ_WORK_FLAGS is defined simply to 3UL. This is confusing as it
says nothing about its purpose. Define IRQ_WORK_FLAGS as a bitwise
OR of IRQ_WORK_PENDING and IRQ_WORK_BUSY and change its name to
IRQ_WORK_CLAIMED.
While we're at it: use the BIT() macro for all flags.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
---
include/linux/irq_work.h | 8 ++++----
kernel/irq_work.c | 2 +-
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index 0e81035..de63339 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -13,10 +13,10 @@
* busy NULL, 2 -> {free, claimed} : callback in progress, can be claimed
*/
-#define IRQ_WORK_PENDING 1UL
-#define IRQ_WORK_BUSY 2UL
-#define IRQ_WORK_FLAGS 3UL
-#define IRQ_WORK_LAZY 4UL /* Doesn't want IPI, wait for tick */
+#define IRQ_WORK_PENDING BIT(0)
+#define IRQ_WORK_BUSY BIT(1)
+#define IRQ_WORK_CLAIMED (IRQ_WORK_PENDING | IRQ_WORK_BUSY)
+#define IRQ_WORK_LAZY BIT(2) /* Doesn't want IPI, wait for tick */
struct irq_work {
unsigned long flags;
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 40e9d73..6b7cdf1 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -36,7 +36,7 @@ static bool irq_work_claim(struct irq_work *work)
*/
flags = work->flags & ~IRQ_WORK_PENDING;
for (;;) {
- nflags = flags | IRQ_WORK_FLAGS;
+ nflags = flags | IRQ_WORK_CLAIMED;
oflags = cmpxchg(&work->flags, flags, nflags);
if (oflags == flags)
break;
--
2.7.4
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2017-08-14 11:56 [PATCH] irq_work: improve the flag definitions Bartosz Golaszewski
2017-08-14 12:19 ` Andy Shevchenko
2017-08-14 17:12 ` Bartosz Golaszewski
2017-08-15 9:12 ` Bartosz Golaszewski
2018-01-05 4:19 [PATCH] irq_work: Improve " Frederic Weisbecker
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