[RESEND PATCH] irq_work: improve the flag definitions

[RESEND PATCH] irq_work: improve the flag definitions

[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 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>
---
 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 0e81035b678f..de6333967d61 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 40e9d739c169..6b7cdf17ccf8 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;
-- 
2.15.0

Re: [RESEND PATCH] irq_work: improve the flag definitions

[Andy Shevchenko]

On Mon, Nov 27, 2017 at 12:52 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 and change its name to
> IRQ_WORK_CLAIMED.
>
> While we're at it: use the BIT() macro for all flags.
>

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
> ---
>  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 0e81035b678f..de6333967d61 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 40e9d739c169..6b7cdf17ccf8 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;
> --
> 2.15.0
>



-- 
With Best Regards,
Andy Shevchenko

Re: [RESEND PATCH] irq_work: improve the flag definitions

[Bartosz Golaszewski]

2017-11-27 11:52 GMT+01:00 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 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>
> ---
>  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 0e81035b678f..de6333967d61 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 40e9d739c169..6b7cdf17ccf8 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;
> --
> 2.15.0
>

It's been a couple months since I first posted this patch. Can it be
applied for 4.16?

@Frederic: I noticed you picked up some irq_work patches in the past
so I'm Cc'ing you.

Best regards,
Bartosz Golaszewski

Re: [RESEND PATCH] irq_work: improve the flag definitions

[Frederic Weisbecker]

2017-11-27 11:52 UTC+01:00, 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 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>

Nice!

Acked-by: Frederic Weisbecker <frederic@kernel.org>

Re: [RESEND PATCH] irq_work: improve the flag definitions

[Frederic Weisbecker]

2017-12-11 11:59 UTC+01:00, Bartosz Golaszewski <brgl@bgdev.pl>:
> 2017-11-27 11:52 GMT+01:00 Bartosz Golaszewski <brgl@bgdev.pl>:
> It's been a couple months since I first posted this patch. Can it be
> applied for 4.16?
>
> @Frederic: I noticed you picked up some irq_work patches in the past
> so I'm Cc'ing you.

Sure, I'll take it!

Thanks!