diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h index 91324c331a4b..440aca5b4b59 100644 --- a/include/linux/iopoll.h +++ b/include/linux/iopoll.h @@ -13,9 +13,104 @@ #include #include +/** + * poll_timeout_us - Periodically poll and perform an operation until + * a condition is met or a timeout occurs + * + * @op: Operation + * @cond: Break condition + * @sleep_us: Maximum time to sleep between operations in us (0 tight-loops). + * Please read usleep_range() function description for details and + * limitations. + * @timeout_us: Timeout in us, 0 means never timeout + * @sleep_before_op: if it is true, sleep @sleep_us before operation. + * + * When available, you'll probably want to use one of the specialized + * macros defined below rather than this macro directly. + * + * Returns: 0 on success and -ETIMEDOUT upon a timeout. Must not + * be called from atomic context if sleep_us or timeout_us are used. + */ +#define poll_timeout_us(op, cond, sleep_us, timeout_us, sleep_before_op) \ +({ \ + 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_op) && __sleep_us) \ + usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ + for (;;) { \ + op; \ + if (cond) \ + break; \ + if (__timeout_us && \ + ktime_compare(ktime_get(), __timeout) > 0) { \ + op; \ + break; \ + } \ + if (__sleep_us) \ + usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ + cpu_relax(); \ + } \ + (cond) ? 0 : -ETIMEDOUT; \ +}) + +/** + * poll_timeout_us_atomic - Periodically poll and perform an operation until + * a condition is met or a timeout occurs + * + * @op: Operation + * @cond: Break condition + * @delay_us: Time to udelay between operations in us (0 tight-loops). + * Please read udelay() function description for details and + * limitations. + * @timeout_us: Timeout in us, 0 means never timeout + * @delay_before_op: if it is true, delay @delay_us before operation. + * + * This macro does not rely on timekeeping. Hence it is safe to call even when + * timekeeping is suspended, at the expense of an underestimation of wall clock + * time, which is rather minimal with a non-zero delay_us. + * + * When available, you'll probably want to use one of the specialized + * macros defined below rather than this macro directly. + * + * Returns: 0 on success and -ETIMEDOUT upon a timeout. + */ +#define poll_timeout_us_atomic(op, cond, delay_us, timeout_us, \ + delay_before_op) \ +({ \ + u64 __timeout_us = (timeout_us); \ + s64 __left_ns = __timeout_us * NSEC_PER_USEC; \ + unsigned long __delay_us = (delay_us); \ + u64 __delay_ns = __delay_us * NSEC_PER_USEC; \ + if ((delay_before_op) && __delay_us) { \ + udelay(__delay_us); \ + if (__timeout_us) \ + __left_ns -= __delay_ns; \ + } \ + for (;;) { \ + op; \ + if (cond) \ + break; \ + if (__timeout_us && __left_ns < 0) { \ + op; \ + break; \ + } \ + if (__delay_us) { \ + udelay(__delay_us); \ + if (__timeout_us) \ + __left_ns -= __delay_ns; \ + } \ + cpu_relax(); \ + if (__timeout_us) \ + __left_ns--; \ + } \ + (cond) ? 0 : -ETIMEDOUT; \ +}) + /** * read_poll_timeout - Periodically poll an address until a condition is - * met or a timeout occurs + * 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) @@ -34,33 +129,12 @@ * be called from atomic context if sleep_us or timeout_us are used. */ #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); \ - cpu_relax(); \ - } \ - (cond) ? 0 : -ETIMEDOUT; \ -}) + sleep_before_read, args...) \ + poll_timeout_us((val) = op(args), cond, sleep_us, timeout_us, sleep_before_read) /** * read_poll_timeout_atomic - Periodically poll an address until a condition is - * met or a timeout occurs + * 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) @@ -81,37 +155,9 @@ * Returns: 0 on success and -ETIMEDOUT upon a timeout. In either * case, the last read value at @args is stored in @val. */ -#define read_poll_timeout_atomic(op, val, cond, delay_us, timeout_us, \ - delay_before_read, args...) \ -({ \ - u64 __timeout_us = (timeout_us); \ - s64 __left_ns = __timeout_us * NSEC_PER_USEC; \ - unsigned long __delay_us = (delay_us); \ - u64 __delay_ns = __delay_us * NSEC_PER_USEC; \ - if (delay_before_read && __delay_us) { \ - udelay(__delay_us); \ - if (__timeout_us) \ - __left_ns -= __delay_ns; \ - } \ - for (;;) { \ - (val) = op(args); \ - if (cond) \ - break; \ - if (__timeout_us && __left_ns < 0) { \ - (val) = op(args); \ - break; \ - } \ - if (__delay_us) { \ - udelay(__delay_us); \ - if (__timeout_us) \ - __left_ns -= __delay_ns; \ - } \ - cpu_relax(); \ - if (__timeout_us) \ - __left_ns--; \ - } \ - (cond) ? 0 : -ETIMEDOUT; \ -}) +#define read_poll_timeout_atomic(op, val, cond, sleep_us, timeout_us, \ + sleep_before_read, args...) \ + poll_timeout_us_atomic((val) = op(args), cond, sleep_us, timeout_us, sleep_before_read) /** * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs