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From: Olav Haugan <ohaugan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Cc: linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	will.deacon-5wv7dgnIgG8@public.gmane.org,
	thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
	Matt Wagantall <mattw-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>,
	vgandhi-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org
Subject: [RFC/PATCH 3/7] iopoll: Introduce memory-mapped IO polling macros
Date: Mon, 30 Jun 2014 09:51:52 -0700	[thread overview]
Message-ID: <1404147116-4598-4-git-send-email-ohaugan@codeaurora.org> (raw)
In-Reply-To: <1404147116-4598-1-git-send-email-ohaugan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

From: Matt Wagantall <mattw-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

It is sometimes necessary to poll a memory-mapped register until its
value satisfies some condition. Introduce a family of convenience macros
that do this. Tight-loop and sleeping versions are provided with and
without timeouts.

Signed-off-by: Matt Wagantall <mattw-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 include/linux/iopoll.h | 114 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 include/linux/iopoll.h

diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h
new file mode 100644
index 0000000..d085e03
--- /dev/null
+++ b/include/linux/iopoll.h
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_IOPOLL_H
+#define _LINUX_IOPOLL_H
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/hrtimer.h>
+#include <linux/delay.h>
+#include <asm-generic/errno.h>
+#include <asm/io.h>
+
+/**
+ * readl_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
+ * @addr: Address to poll
+ * @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)
+ * @timeout_us: Timeout in uS, 0 means never timeout
+ *
+ * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
+ * case, the last read value at @addr is stored in @val. Must not
+ * be called from atomic context if sleep_us or timeout_us are used.
+ */
+#define readl_poll_timeout(addr, val, cond, sleep_us, timeout_us) \
+({ \
+	ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \
+	might_sleep_if(timeout_us); \
+	for (;;) { \
+		(val) = readl(addr); \
+		if (cond) \
+			break; \
+		if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \
+			(val) = readl(addr); \
+			break; \
+		} \
+		if (sleep_us) \
+			usleep_range(DIV_ROUND_UP(sleep_us, 4), sleep_us); \
+	} \
+	(cond) ? 0 : -ETIMEDOUT; \
+})
+
+/**
+ * readl_poll_timeout_noirq - Periodically poll an address until a condition is met or a timeout occurs
+ * @addr: Address to poll
+ * @val: Variable to read the value into
+ * @cond: Break condition (usually involving @val)
+ * @max_reads: Maximum number of reads before giving up
+ * @time_between_us: Time to udelay() between successive reads
+ *
+ * Returns 0 on success and -ETIMEDOUT upon a timeout.
+ */
+#define readl_poll_timeout_noirq(addr, val, cond, max_reads, time_between_us) \
+({ \
+	int count; \
+	for (count = (max_reads); count > 0; count--) { \
+		(val) = readl(addr); \
+		if (cond) \
+			break; \
+		udelay(time_between_us); \
+	} \
+	(cond) ? 0 : -ETIMEDOUT; \
+})
+
+/**
+ * readl_poll - Periodically poll an address until a condition is met
+ * @addr: Address to poll
+ * @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)
+ *
+ * Must not be called from atomic context if sleep_us is used.
+ */
+#define readl_poll(addr, val, cond, sleep_us) \
+	readl_poll_timeout(addr, val, cond, sleep_us, 0)
+
+/**
+ * readl_tight_poll_timeout - Tight-loop on an address until a condition is met or a timeout occurs
+ * @addr: Address to poll
+ * @val: Variable to read the value into
+ * @cond: Break condition (usually involving @val)
+ * @timeout_us: Timeout in uS, 0 means never timeout
+ *
+ * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
+ * case, the last read value at @addr is stored in @val. Must not
+ * be called from atomic context if timeout_us is used.
+ */
+#define readl_tight_poll_timeout(addr, val, cond, timeout_us) \
+	readl_poll_timeout(addr, val, cond, 0, timeout_us)
+
+/**
+ * readl_tight_poll - Tight-loop on an address until a condition is met
+ * @addr: Address to poll
+ * @val: Variable to read the value into
+ * @cond: Break condition (usually involving @val)
+ *
+ * May be called from atomic context.
+ */
+#define readl_tight_poll(addr, val, cond) \
+	readl_poll_timeout(addr, val, cond, 0, 0)
+
+#endif /* _LINUX_IOPOLL_H */
-- 
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

WARNING: multiple messages have this Message-ID (diff)
From: ohaugan@codeaurora.org (Olav Haugan)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC/PATCH 3/7] iopoll: Introduce memory-mapped IO polling macros
Date: Mon, 30 Jun 2014 09:51:52 -0700	[thread overview]
Message-ID: <1404147116-4598-4-git-send-email-ohaugan@codeaurora.org> (raw)
In-Reply-To: <1404147116-4598-1-git-send-email-ohaugan@codeaurora.org>

From: Matt Wagantall <mattw@codeaurora.org>

It is sometimes necessary to poll a memory-mapped register until its
value satisfies some condition. Introduce a family of convenience macros
that do this. Tight-loop and sleeping versions are provided with and
without timeouts.

Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
---
 include/linux/iopoll.h | 114 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 include/linux/iopoll.h

diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h
new file mode 100644
index 0000000..d085e03
--- /dev/null
+++ b/include/linux/iopoll.h
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_IOPOLL_H
+#define _LINUX_IOPOLL_H
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/hrtimer.h>
+#include <linux/delay.h>
+#include <asm-generic/errno.h>
+#include <asm/io.h>
+
+/**
+ * readl_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
+ * @addr: Address to poll
+ * @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)
+ * @timeout_us: Timeout in uS, 0 means never timeout
+ *
+ * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
+ * case, the last read value at @addr is stored in @val. Must not
+ * be called from atomic context if sleep_us or timeout_us are used.
+ */
+#define readl_poll_timeout(addr, val, cond, sleep_us, timeout_us) \
+({ \
+	ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \
+	might_sleep_if(timeout_us); \
+	for (;;) { \
+		(val) = readl(addr); \
+		if (cond) \
+			break; \
+		if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \
+			(val) = readl(addr); \
+			break; \
+		} \
+		if (sleep_us) \
+			usleep_range(DIV_ROUND_UP(sleep_us, 4), sleep_us); \
+	} \
+	(cond) ? 0 : -ETIMEDOUT; \
+})
+
+/**
+ * readl_poll_timeout_noirq - Periodically poll an address until a condition is met or a timeout occurs
+ * @addr: Address to poll
+ * @val: Variable to read the value into
+ * @cond: Break condition (usually involving @val)
+ * @max_reads: Maximum number of reads before giving up
+ * @time_between_us: Time to udelay() between successive reads
+ *
+ * Returns 0 on success and -ETIMEDOUT upon a timeout.
+ */
+#define readl_poll_timeout_noirq(addr, val, cond, max_reads, time_between_us) \
+({ \
+	int count; \
+	for (count = (max_reads); count > 0; count--) { \
+		(val) = readl(addr); \
+		if (cond) \
+			break; \
+		udelay(time_between_us); \
+	} \
+	(cond) ? 0 : -ETIMEDOUT; \
+})
+
+/**
+ * readl_poll - Periodically poll an address until a condition is met
+ * @addr: Address to poll
+ * @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)
+ *
+ * Must not be called from atomic context if sleep_us is used.
+ */
+#define readl_poll(addr, val, cond, sleep_us) \
+	readl_poll_timeout(addr, val, cond, sleep_us, 0)
+
+/**
+ * readl_tight_poll_timeout - Tight-loop on an address until a condition is met or a timeout occurs
+ * @addr: Address to poll
+ * @val: Variable to read the value into
+ * @cond: Break condition (usually involving @val)
+ * @timeout_us: Timeout in uS, 0 means never timeout
+ *
+ * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
+ * case, the last read value at @addr is stored in @val. Must not
+ * be called from atomic context if timeout_us is used.
+ */
+#define readl_tight_poll_timeout(addr, val, cond, timeout_us) \
+	readl_poll_timeout(addr, val, cond, 0, timeout_us)
+
+/**
+ * readl_tight_poll - Tight-loop on an address until a condition is met
+ * @addr: Address to poll
+ * @val: Variable to read the value into
+ * @cond: Break condition (usually involving @val)
+ *
+ * May be called from atomic context.
+ */
+#define readl_tight_poll(addr, val, cond) \
+	readl_poll_timeout(addr, val, cond, 0, 0)
+
+#endif /* _LINUX_IOPOLL_H */
-- 
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

  parent reply	other threads:[~2014-06-30 16:51 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-30 16:51 [RFC/PATCH 0/7] Add MSM SMMUv1 support Olav Haugan
2014-06-30 16:51 ` Olav Haugan
2014-06-30 16:51 ` [RFC/PATCH 1/7] iommu: msm: Rename iommu driver files Olav Haugan
2014-06-30 16:51   ` Olav Haugan
2014-06-30 16:51 ` [RFC/PATCH 2/7] iommu-api: Add map_range/unmap_range functions Olav Haugan
2014-06-30 16:51   ` Olav Haugan
2014-06-30 19:42   ` Thierry Reding
2014-06-30 19:42     ` Thierry Reding
2014-07-01  9:33   ` Will Deacon
2014-07-01  9:33     ` Will Deacon
2014-07-01  9:58     ` Varun Sethi
2014-07-01  9:58       ` Varun Sethi
2014-07-04  4:29   ` Hiroshi Doyu
2014-07-04  4:29     ` Hiroshi Doyu
2014-07-08 21:53     ` Olav Haugan
2014-07-08 21:53       ` Olav Haugan
2014-07-08 23:49       ` Rob Clark
2014-07-08 23:49         ` Rob Clark
2014-07-10  0:03         ` Olav Haugan
2014-07-10  0:03           ` Olav Haugan
     [not found]           ` <53BDD834.5030405-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2014-07-10  0:40             ` Rob Clark
2014-07-10  0:40               ` Rob Clark
2014-07-10  7:10               ` Thierry Reding
2014-07-10  7:10                 ` Thierry Reding
2014-07-10 11:15                 ` Rob Clark
2014-07-10 11:15                   ` Rob Clark
     [not found]               ` <CAF6AEGucNbo7sm9oQWFq9hcfoSeR5DuwRcRUvG+Y2sxLaM7OTQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-07-10 22:43                 ` Olav Haugan
2014-07-10 22:43                   ` Olav Haugan
2014-07-10 23:42                   ` Rob Clark
2014-07-10 23:42                     ` Rob Clark
2014-07-11 10:20   ` Joerg Roedel
2014-07-11 10:20     ` Joerg Roedel
     [not found]     ` <20140711102053.GB1958-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2014-07-15  1:13       ` Olav Haugan
2014-07-15  1:13         ` Olav Haugan
     [not found] ` <1404147116-4598-1-git-send-email-ohaugan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2014-06-30 16:51   ` Olav Haugan [this message]
2014-06-30 16:51     ` [RFC/PATCH 3/7] iopoll: Introduce memory-mapped IO polling macros Olav Haugan
     [not found]     ` <1404147116-4598-4-git-send-email-ohaugan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2014-06-30 19:46       ` Thierry Reding
2014-06-30 19:46         ` Thierry Reding
2014-07-01  9:40       ` Will Deacon
2014-07-01  9:40         ` Will Deacon
2014-06-30 16:51   ` [RFC/PATCH 4/7] iommu: msm: Add MSM IOMMUv1 driver Olav Haugan
     [not found]     ` <1404147116-4598-5-git-send-email-ohaugan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2014-06-30 17:02       ` Will Deacon
2014-06-30 17:02         ` Will Deacon
     [not found]         ` <20140630170221.GA30740-5wv7dgnIgG8@public.gmane.org>
2014-07-02 22:32           ` Olav Haugan
2014-07-02 22:32             ` Olav Haugan
2014-06-30 16:51 ` [RFC/PATCH 5/7] iommu: msm: Add support for V7L page table format Olav Haugan
2014-06-30 16:51   ` Olav Haugan
2014-06-30 16:51 ` [RFC/PATCH 6/7] defconfig: msm: Enable Qualcomm SMMUv1 driver Olav Haugan
2014-06-30 16:51   ` Olav Haugan
2014-06-30 16:51 ` [RFC/PATCH 7/7] iommu-api: Add domain attribute to enable coherent HTW Olav Haugan
2014-06-30 16:51   ` Olav Haugan
     [not found]   ` <1404147116-4598-8-git-send-email-ohaugan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2014-07-01  8:49     ` Varun Sethi
2014-07-01  8:49       ` Varun Sethi
2014-07-02 22:11       ` Olav Haugan
2014-07-02 22:11         ` Olav Haugan
     [not found]         ` <53B48381.9050707-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2014-07-03 17:43           ` Will Deacon
2014-07-03 17:43             ` Will Deacon
     [not found]             ` <20140703174321.GE17372-5wv7dgnIgG8@public.gmane.org>
2014-07-08 22:24               ` Olav Haugan
2014-07-08 22:24                 ` Olav Haugan

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