From: Hauke Mehrtens <hauke@hauke-m.de>
To: backports@vger.kernel.org
Cc: johannes@sipsolutions.net, Hauke Mehrtens <hauke@hauke-m.de>
Subject: [PATCH 3/7] backports: Add read_poll_timeout{_atomic}()
Date: Mon, 22 Jun 2020 23:38:00 +0200 [thread overview]
Message-ID: <20200622213804.26477-4-hauke@hauke-m.de> (raw)
In-Reply-To: <20200622213804.26477-1-hauke@hauke-m.de>
These defines are used by the rtw88 driver.
These defines are copied from Linux commit 5f5323a14cad ("iopoll:
introduce read_poll_timeout macro") and 57a29df34146 ("iopoll: Introduce
read_poll_timeout_atomic macro")
linux/iopoll.h was only added in kernel 4.20, do not include the
original file in older versions.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
backport/backport-include/linux/iopoll.h | 98 ++++++++++++++++++++++++
1 file changed, 98 insertions(+)
create mode 100644 backport/backport-include/linux/iopoll.h
diff --git a/backport/backport-include/linux/iopoll.h b/backport/backport-include/linux/iopoll.h
new file mode 100644
index 00000000..f50187ad
--- /dev/null
+++ b/backport/backport-include/linux/iopoll.h
@@ -0,0 +1,98 @@
+#ifndef _BACKPORTS_LINUX_IOPOLL_H
+#define _BACKPORTS_LINUX_IOPOLL_H 1
+
+#if LINUX_VERSION_IS_GEQ(4,0,0)
+#include_next <linux/iopoll.h>
+#endif
+
+#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 */
--
2.20.1
--
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next prev parent reply other threads:[~2020-06-22 21:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-22 21:37 [PATCH 0/7] backports: Update to version 5.8-rc2 Hauke Mehrtens
2020-06-22 21:37 ` [PATCH 1/7] backports: patches: Refresh on kernel 5.8-rc2 Hauke Mehrtens
2020-06-22 21:37 ` [PATCH 2/7] backports: Add fallthrough attribute Hauke Mehrtens
2020-06-22 21:38 ` Hauke Mehrtens [this message]
2020-06-22 21:38 ` [PATCH 4/7] backports: Add GUID_INIT() Hauke Mehrtens
2020-06-22 21:38 ` [PATCH 5/7] backports: Adapt acpi_evaluate_dsm() Hauke Mehrtens
2020-06-22 21:38 ` [PATCH 6/7] backports: dependencies: Add new mt76 driver options Hauke Mehrtens
2020-06-22 21:38 ` [PATCH 7/7] backports: Include missing header file for mt76 Hauke Mehrtens
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