From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/block/paride/pseudo.h | 102 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 drivers/block/paride/pseudo.h (limited to 'drivers/block/paride/pseudo.h') diff --git a/drivers/block/paride/pseudo.h b/drivers/block/paride/pseudo.h new file mode 100644 index 000000000..bc3703294 --- /dev/null +++ b/drivers/block/paride/pseudo.h @@ -0,0 +1,102 @@ +/* + pseudo.h (c) 1997-8 Grant R. Guenther + Under the terms of the GNU General Public License. + + This is the "pseudo-interrupt" logic for parallel port drivers. + + This module is #included into each driver. It makes one + function available: + + ps_set_intr( void (*continuation)(void), + int (*ready)(void), + int timeout, + int nice ) + + Which will arrange for ready() to be evaluated frequently and + when either it returns true, or timeout jiffies have passed, + continuation() will be invoked. + + If nice is 1, the test will done approximately once a + jiffy. If nice is 0, the test will also be done whenever + the scheduler runs (by adding it to a task queue). If + nice is greater than 1, the test will be done once every + (nice-1) jiffies. + +*/ + +/* Changes: + + 1.01 1998.05.03 Switched from cli()/sti() to spinlocks + 1.02 1998.12.14 Added support for nice > 1 +*/ + +#define PS_VERSION "1.02" + +#include +#include + +static void ps_tq_int(struct work_struct *work); + +static void (* ps_continuation)(void); +static int (* ps_ready)(void); +static unsigned long ps_timeout; +static int ps_tq_active = 0; +static int ps_nice = 0; + +static DEFINE_SPINLOCK(ps_spinlock __attribute__((unused))); + +static DECLARE_DELAYED_WORK(ps_tq, ps_tq_int); + +static void ps_set_intr(void (*continuation)(void), + int (*ready)(void), + int timeout, int nice) +{ + unsigned long flags; + + spin_lock_irqsave(&ps_spinlock,flags); + + ps_continuation = continuation; + ps_ready = ready; + ps_timeout = jiffies + timeout; + ps_nice = nice; + + if (!ps_tq_active) { + ps_tq_active = 1; + if (!ps_nice) + schedule_delayed_work(&ps_tq, 0); + else + schedule_delayed_work(&ps_tq, ps_nice-1); + } + spin_unlock_irqrestore(&ps_spinlock,flags); +} + +static void ps_tq_int(struct work_struct *work) +{ + void (*con)(void); + unsigned long flags; + + spin_lock_irqsave(&ps_spinlock,flags); + + con = ps_continuation; + ps_tq_active = 0; + + if (!con) { + spin_unlock_irqrestore(&ps_spinlock,flags); + return; + } + if (!ps_ready || ps_ready() || time_after_eq(jiffies, ps_timeout)) { + ps_continuation = NULL; + spin_unlock_irqrestore(&ps_spinlock,flags); + con(); + return; + } + ps_tq_active = 1; + if (!ps_nice) + schedule_delayed_work(&ps_tq, 0); + else + schedule_delayed_work(&ps_tq, ps_nice-1); + spin_unlock_irqrestore(&ps_spinlock,flags); +} + +/* end of pseudo.h */ + -- cgit v1.2.3-54-g00ecf