Like read_poll_timeout, an atomic variant for multiple parameter read
function can be useful.
Will be used by a later patch.
Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
---
v2:
- Cc linux-wireless.
include/linux/iopoll.h | 62 +++++++++++++++++++++++++++++-------------
1 file changed, 43 insertions(+), 19 deletions(-)
diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h
index cb20c733b15a..bc89ac625f26 100644
--- a/include/linux/iopoll.h
+++ b/include/linux/iopoll.h
@@ -57,6 +57,48 @@
(cond) ? 0 : -ETIMEDOUT; \
})
+/**
+ * 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; \
+})
+
/**
* readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
* @op: accessor function (takes @addr as its only argument)
@@ -96,25 +138,7 @@
* macros defined below rather than this macro directly.
*/
#define readx_poll_timeout_atomic(op, addr, val, cond, delay_us, timeout_us) \
-({ \
- u64 __timeout_us = (timeout_us); \
- unsigned long __delay_us = (delay_us); \
- ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
- for (;;) { \
- (val) = op(addr); \
- if (cond) \
- break; \
- if (__timeout_us && \
- ktime_compare(ktime_get(), __timeout) > 0) { \
- (val) = op(addr); \
- break; \
- } \
- if (__delay_us) \
- udelay(__delay_us); \
- } \
- (cond) ? 0 : -ETIMEDOUT; \
-})
-
+ read_poll_timeout_atomic(op, val, cond, delay_us, timeout_us, false, addr)
#define readb_poll_timeout(addr, val, cond, delay_us, timeout_us) \
readx_poll_timeout(readb, addr, val, cond, delay_us, timeout_us)
--
2.17.1
