diff options
| author | Johannes Berg <johannes.berg@intel.com> | 2020-12-02 12:59:50 +0100 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2020-12-13 22:22:08 +0100 |
| commit | 36d46a5907ba170965307c9d106cc35517acbf33 (patch) | |
| tree | 35b1748a7ab1981f00903874a34d68b9977aee60 /arch/um/drivers/line.c | |
| parent | d66c91836b8d7df3b6f0fe7f0c7617d28ebfcb4c (diff) | |
| download | linux-36d46a5907ba170965307c9d106cc35517acbf33.tar.bz2 | |
um: Support dynamic IRQ allocation
It's cumbersome and error-prone to keep adding fixed IRQ numbers,
and for proper device wakeup support for the virtio/vhost-user
support we need to have different IRQs for each device. Even if
in theory two IRQs (with and without wake) might be sufficient,
it's much easier to reason about it when we have dynamic number
assignment. It also makes it easier to add new devices that may
dynamically exist or depending on the configuration, etc.
Add support for this, up to 64 IRQs (the same limit as epoll FDs
we have right now). Since it's not easy to port all the existing
places to dynamic allocation (some data is statically initialized)
keep the low numbers are reserved for the existing hard-coded IRQ
numbers.
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/drivers/line.c')
| -rw-r--r-- | arch/um/drivers/line.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c index 77ce63a57070..1c70a31e7c5b 100644 --- a/arch/um/drivers/line.c +++ b/arch/um/drivers/line.c @@ -262,19 +262,25 @@ static irqreturn_t line_write_interrupt(int irq, void *data) int line_setup_irq(int fd, int input, int output, struct line *line, void *data) { const struct line_driver *driver = line->driver; - int err = 0; + int err; - if (input) + if (input) { err = um_request_irq(driver->read_irq, fd, IRQ_READ, line_interrupt, IRQF_SHARED, driver->read_irq_name, data); - if (err) - return err; - if (output) + if (err < 0) + return err; + } + + if (output) { err = um_request_irq(driver->write_irq, fd, IRQ_WRITE, line_write_interrupt, IRQF_SHARED, driver->write_irq_name, data); - return err; + if (err < 0) + return err; + } + + return 0; } static int line_activate(struct tty_port *port, struct tty_struct *tty) |