diff options
| author |   Barry Song <song.bao.hua@hisilicon.com> | 2021-03-03 11:49:15 +1300 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2021-03-06 12:48:00 +0100 |
| commit | cbe16f35bee6880becca6f20d2ebf6b457148552 (patch) | |
| tree | 4c82c004e0be2e9100af1407c11b5f35028a0d48 /include/linux/interrupt.h | |
| parent | Linux 5.12-rc2 (diff) | |
| download | wireguard-linux-cbe16f35bee6880becca6f20d2ebf6b457148552.tar.xz wireguard-linux-cbe16f35bee6880becca6f20d2ebf6b457148552.zip | |
genirq: Add IRQF_NO_AUTOEN for request_irq/nmi()
Many drivers don't want interrupts enabled automatically via request_irq().
So they are handling this issue by either way of the below two:
(1)
irq_set_status_flags(irq, IRQ_NOAUTOEN);
request_irq(dev, irq...);
(2)
request_irq(dev, irq...);
disable_irq(irq);
The code in the second way is silly and unsafe. In the small time gap
between request_irq() and disable_irq(), interrupts can still come.
The code in the first way is safe though it's subobtimal.
Add a new IRQF_NO_AUTOEN flag which can be handed in by drivers to
request_irq() and request_nmi(). It prevents the automatic enabling of the
requested interrupt/nmi in the same safe way as #1 above. With that the
various usage sites of #1 and #2 above can be simplified and corrected.
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: dmitry.torokhov@gmail.com
Link: https://lore.kernel.org/r/20210302224916.13980-2-song.bao.hua@hisilicon.com
Diffstat (limited to 'include/linux/interrupt.h')
| -rw-r--r-- | include/linux/interrupt.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 967e25767153..76f1161a441a 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -61,6 +61,9 @@ * interrupt handler after suspending interrupts. For system * wakeup devices users need to implement wakeup detection in * their interrupt handlers. + * IRQF_NO_AUTOEN - Don't enable IRQ or NMI automatically when users request it. + * Users will enable it explicitly by enable_irq() or enable_nmi() + * later. */ #define IRQF_SHARED 0x00000080 #define IRQF_PROBE_SHARED 0x00000100 @@ -74,6 +77,7 @@ #define IRQF_NO_THREAD 0x00010000 #define IRQF_EARLY_RESUME 0x00020000 #define IRQF_COND_SUSPEND 0x00040000 +#define IRQF_NO_AUTOEN 0x00080000 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD) |