#ifndef _BACKPORTS_LINUX_IOPOLL_H #define _BACKPORTS_LINUX_IOPOLL_H 1 #include_next #ifndef read_poll_timeout /** * read_poll_timeout - Periodically poll an address until a condition is * met or a timeout occurs * @op: accessor function (takes @args as its arguments) * @val: Variable to read the value into * @cond: Break condition (usually involving @val) * @sleep_us: Maximum time to sleep between reads in us (0 * tight-loops). Should be less than ~20ms since usleep_range * is used (see Documentation/timers/timers-howto.rst). * @timeout_us: Timeout in us, 0 means never timeout * @sleep_before_read: if it is true, sleep @sleep_us before read. * @args: arguments for @op poll * * Returns 0 on success and -ETIMEDOUT upon a timeout. In either * case, the last read value at @args is stored in @val. Must not * be called from atomic context if sleep_us or timeout_us are used. * * When available, you'll probably want to use one of the specialized * macros defined below rather than this macro directly. */ #define read_poll_timeout(op, val, cond, sleep_us, timeout_us, \ sleep_before_read, args...) \ ({ \ u64 __timeout_us = (timeout_us); \ unsigned long __sleep_us = (sleep_us); \ ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \ might_sleep_if((__sleep_us) != 0); \ if (sleep_before_read && __sleep_us) \ usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ for (;;) { \ (val) = op(args); \ if (cond) \ break; \ if (__timeout_us && \ ktime_compare(ktime_get(), __timeout) > 0) { \ (val) = op(args); \ break; \ } \ if (__sleep_us) \ usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ } \ (cond) ? 0 : -ETIMEDOUT; \ }) #endif /* read_poll_timeout */ #ifndef read_poll_timeout_atomic /** * read_poll_timeout_atomic - Periodically poll an address until a condition is * met or a timeout occurs * @op: accessor function (takes @addr as its only argument) * @addr: Address to poll * @val: Variable to read the value into * @cond: Break condition (usually involving @val) * @delay_us: Time to udelay between reads in us (0 tight-loops). Should * be less than ~10us since udelay is used (see * Documentation/timers/timers-howto.rst). * @timeout_us: Timeout in us, 0 means never timeout * @delay_before_read: if it is true, delay @delay_us before read. * * Returns 0 on success and -ETIMEDOUT upon a timeout. In either * case, the last read value at @args is stored in @val. * * When available, you'll probably want to use one of the specialized * macros defined below rather than this macro directly. */ #define read_poll_timeout_atomic(op, val, cond, delay_us, timeout_us, \ delay_before_read, args...) \ ({ \ u64 __timeout_us = (timeout_us); \ unsigned long __delay_us = (delay_us); \ ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \ if (delay_before_read && __delay_us) \ udelay(__delay_us); \ for (;;) { \ (val) = op(args); \ if (cond) \ break; \ if (__timeout_us && \ ktime_compare(ktime_get(), __timeout) > 0) { \ (val) = op(args); \ break; \ } \ if (__delay_us) \ udelay(__delay_us); \ } \ (cond) ? 0 : -ETIMEDOUT; \ }) #endif /* read_poll_timeout_atomic */ #endif /* _BACKPORTS_LINUX_IOPOLL_H */