From: William Breathitt Gray <vilhelm.gray@gmail.com>
To: jic23@kernel.org
Cc: kernel@pengutronix.de, linux-stm32@st-md-mailman.stormreply.com,
a.fatoum@pengutronix.de, kamel.bouhara@bootlin.com,
gwendal@chromium.org, alexandre.belloni@bootlin.com,
david@lechnology.com, linux-iio@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, syednwaris@gmail.com,
patrick.havelange@essensium.com, fabrice.gasnier@st.com,
mcoquelin.stm32@gmail.com, alexandre.torgue@st.com,
o.rempel@pengutronix.de,
William Breathitt Gray <vilhelm.gray@gmail.com>
Subject: [PATCH v10 31/33] counter: Implement events_queue_size sysfs attribute
Date: Fri, 19 Mar 2021 20:00:50 +0900 [thread overview]
Message-ID: <052410b645d7c2ce47f78540cfa93ebad489c1df.1616150619.git.vilhelm.gray@gmail.com> (raw)
In-Reply-To: <cover.1616150619.git.vilhelm.gray@gmail.com>
The events_queue_size sysfs attribute provides a way for users to
dynamically configure the Counter events queue size for the Counter
character device interface. The size is in number of struct
counter_event data structures. The number of elements will be rounded-up
to a power of 2 due to a requirement of the kfifo_alloc function called
during reallocation of the queue.
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
Documentation/ABI/testing/sysfs-bus-counter | 8 ++++
drivers/counter/counter-chrdev.c | 4 ++
drivers/counter/counter-sysfs.c | 44 +++++++++++++++++++++
include/linux/counter.h | 2 +
4 files changed, 58 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter
index 57b051ba53a9..a97d85e97184 100644
--- a/Documentation/ABI/testing/sysfs-bus-counter
+++ b/Documentation/ABI/testing/sysfs-bus-counter
@@ -224,6 +224,14 @@ Description:
Read-only attribute that indicates the component ID of the
respective extension or Synapse.
+What: /sys/bus/counter/devices/counterX/events_queue_size
+KernelVersion: 5.13
+Contact: linux-iio@vger.kernel.org
+Description:
+ Size of the Counter events queue in number of struct
+ counter_event data structures. The number of elements will be
+ rounded-up to a power of 2.
+
What: /sys/bus/counter/devices/counterX/name
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
diff --git a/drivers/counter/counter-chrdev.c b/drivers/counter/counter-chrdev.c
index d5f92b2d3bb4..d9f123ca0ed6 100644
--- a/drivers/counter/counter-chrdev.c
+++ b/drivers/counter/counter-chrdev.c
@@ -311,6 +311,9 @@ static int counter_chrdev_open(struct inode *inode, struct file *filp)
typeof(*counter),
chrdev);
+ if (!mutex_trylock(&counter->chrdev_lock))
+ return -EBUSY;
+
get_device(&counter->dev);
filp->private_data = counter;
@@ -327,6 +330,7 @@ static int counter_chrdev_release(struct inode *inode, struct file *filp)
return err;
put_device(&counter->dev);
+ mutex_unlock(&counter->chrdev_lock);
return 0;
}
diff --git a/drivers/counter/counter-sysfs.c b/drivers/counter/counter-sysfs.c
index eb1505bfbd89..bf038eff4587 100644
--- a/drivers/counter/counter-sysfs.c
+++ b/drivers/counter/counter-sysfs.c
@@ -8,7 +8,9 @@
#include <linux/err.h>
#include <linux/gfp.h>
#include <linux/kernel.h>
+#include <linux/kfifo.h>
#include <linux/list.h>
+#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/types.h>
@@ -782,12 +784,48 @@ static int counter_num_counts_read(struct counter_device *counter, u8 *val)
return 0;
}
+static int counter_events_queue_size_read(struct counter_device *counter,
+ u64 *val)
+{
+ *val = kfifo_size(&counter->events);
+ return 0;
+}
+
+static int counter_events_queue_size_write(struct counter_device *counter,
+ u64 val)
+{
+ int err;
+ DECLARE_KFIFO_PTR(events, struct counter_event);
+
+ /* Verify chrdev is not currently being used */
+ if (!mutex_trylock(&counter->chrdev_lock))
+ return -EBUSY;
+
+ /* Allocate new events queue */
+ err = kfifo_alloc(&events, val, GFP_ATOMIC);
+ if (err)
+ return err;
+
+ /* Swap in new events queue */
+ kfifo_free(&counter->events);
+ counter->events.kfifo = events.kfifo;
+
+ mutex_unlock(&counter->chrdev_lock);
+
+ return 0;
+}
+
static struct counter_comp counter_num_signals_comp =
COUNTER_COMP_DEVICE_U8("num_signals", counter_num_signals_read, NULL);
static struct counter_comp counter_num_counts_comp =
COUNTER_COMP_DEVICE_U8("num_counts", counter_num_counts_read, NULL);
+static struct counter_comp counter_events_queue_size_comp =
+ COUNTER_COMP_DEVICE_U64("events_queue_size",
+ counter_events_queue_size_read,
+ counter_events_queue_size_write);
+
static int counter_sysfs_attr_add(struct counter_device *const counter,
struct counter_attribute_group *group)
{
@@ -826,6 +864,12 @@ static int counter_sysfs_attr_add(struct counter_device *const counter,
if (err < 0)
return err;
+ /* Create num_counts attribute */
+ err = counter_attr_create(dev, group, &counter_events_queue_size_comp,
+ scope, NULL);
+ if (err < 0)
+ return err;
+
/* Create an attribute for each extension */
for (i = 0; i < counter->num_ext; i++) {
ext = counter->ext + i;
diff --git a/include/linux/counter.h b/include/linux/counter.h
index 3f0bbe4ff702..854fcaf49c32 100644
--- a/include/linux/counter.h
+++ b/include/linux/counter.h
@@ -289,6 +289,7 @@ struct counter_ops {
* @priv: optional private data supplied by driver
* @dev: internal device structure
* @chrdev: internal character device structure
+ * @chrdev_lock: lock to limit chrdev to a single open at a time
* @events_list: list of current watching Counter events
* @events_list_lock: lock to protect Counter events list operations
* @next_events_list: list of next watching Counter events
@@ -314,6 +315,7 @@ struct counter_device {
struct device dev;
struct cdev chrdev;
+ struct mutex chrdev_lock;
struct list_head events_list;
spinlock_t events_list_lock;
struct list_head next_events_list;
--
2.30.2
next prev parent reply other threads:[~2021-03-19 11:04 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 11:00 [PATCH v10 00/33] Introduce the Counter character device interface William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 01/33] docs: counter: Consolidate Counter sysfs attributes documentation William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 02/33] docs: counter: Fix spelling William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 03/33] counter: 104-quad-8: Remove pointless comment William Breathitt Gray
2021-04-15 15:13 ` Syed Nayyar Waris
2021-03-19 11:00 ` [PATCH v10 04/33] counter: 104-quad-8: Return error when invalid mode during ceiling_write William Breathitt Gray
2021-04-15 15:14 ` Syed Nayyar Waris
2021-03-19 11:00 ` [PATCH v10 05/33] counter: 104-quad-8: Annotate hardware config module parameter William Breathitt Gray
2021-04-15 15:15 ` Syed Nayyar Waris
2021-03-19 11:00 ` [PATCH v10 06/33] counter: 104-quad-8: Add const qualifiers for quad8_preset_register_set William Breathitt Gray
2021-04-15 15:16 ` Syed Nayyar Waris
2021-03-19 11:00 ` [PATCH v10 07/33] counter: 104-quad-8: Add const qualifier for functions_list array William Breathitt Gray
2021-04-15 15:17 ` Syed Nayyar Waris
2021-03-19 11:00 ` [PATCH v10 08/33] counter: interrupt-cnt: " William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 09/33] counter: microchip-tcb-capture: " William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 10/33] counter: stm32-lptimer-cnt: " William Breathitt Gray
2021-03-22 16:22 ` [Linux-stm32] " Fabrice Gasnier
2021-03-19 11:00 ` [PATCH v10 11/33] counter: stm32-timer-cnt: " William Breathitt Gray
2021-03-22 16:22 ` [Linux-stm32] " Fabrice Gasnier
2021-03-19 11:00 ` [PATCH v10 12/33] counter: 104-quad-8: Add const qualifier for actions_list array William Breathitt Gray
2021-04-15 15:18 ` Syed Nayyar Waris
2021-03-19 11:00 ` [PATCH v10 13/33] counter: ftm-quaddec: " William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 14/33] counter: interrupt-cnt: " William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 15/33] counter: microchip-tcb-capture: " William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 16/33] counter: stm32-lptimer-cnt: " William Breathitt Gray
2021-03-22 16:23 ` [Linux-stm32] " Fabrice Gasnier
2021-03-19 11:00 ` [PATCH v10 17/33] counter: stm32-timer-cnt: " William Breathitt Gray
2021-03-22 16:24 ` [Linux-stm32] " Fabrice Gasnier
2021-03-19 11:00 ` [PATCH v10 18/33] counter: Return error code on invalid modes William Breathitt Gray
2021-03-22 16:26 ` [Linux-stm32] " Fabrice Gasnier
2021-04-15 15:19 ` Syed Nayyar Waris
2021-03-19 11:00 ` [PATCH v10 19/33] counter: Standardize to ERANGE for limit exceeded errors William Breathitt Gray
2021-03-22 16:29 ` [Linux-stm32] " Fabrice Gasnier
2021-04-15 15:20 ` Syed Nayyar Waris
2021-03-19 11:00 ` [PATCH v10 20/33] counter: Rename counter_signal_value to counter_signal_level William Breathitt Gray
2021-04-15 15:21 ` Syed Nayyar Waris
2021-03-19 11:00 ` [PATCH v10 21/33] counter: Rename counter_count_function to counter_function William Breathitt Gray
2021-03-22 16:31 ` [Linux-stm32] " Fabrice Gasnier
2021-04-15 15:22 ` Syed Nayyar Waris
2021-03-19 11:00 ` [PATCH v10 22/33] counter: Internalize sysfs interface code William Breathitt Gray
2021-03-22 16:44 ` [Linux-stm32] " Fabrice Gasnier
2021-03-23 9:17 ` William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 23/33] counter: Update counter.h comments to reflect sysfs internalization William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 24/33] docs: counter: Update " William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 25/33] counter: Move counter enums to uapi header William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 26/33] counter: Add character device interface William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 27/33] docs: counter: Document " William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 28/33] tools/counter: Create Counter tools William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 29/33] counter: Implement signalZ_action_component_id sysfs attribute William Breathitt Gray
2021-03-19 11:00 ` [PATCH v10 30/33] counter: Implement *_component_id sysfs attributes William Breathitt Gray
2021-03-19 11:00 ` William Breathitt Gray [this message]
2021-03-19 11:00 ` [PATCH v10 32/33] counter: 104-quad-8: Replace mutex with spinlock William Breathitt Gray
2021-04-15 15:24 ` Syed Nayyar Waris
2021-03-19 11:00 ` [PATCH v10 33/33] counter: 104-quad-8: Add IRQ support for the ACCES 104-QUAD-8 William Breathitt Gray
2021-04-15 15:25 ` Syed Nayyar Waris
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=052410b645d7c2ce47f78540cfa93ebad489c1df.1616150619.git.vilhelm.gray@gmail.com \
--to=vilhelm.gray@gmail.com \
--cc=a.fatoum@pengutronix.de \
--cc=alexandre.belloni@bootlin.com \
--cc=alexandre.torgue@st.com \
--cc=david@lechnology.com \
--cc=fabrice.gasnier@st.com \
--cc=gwendal@chromium.org \
--cc=jic23@kernel.org \
--cc=kamel.bouhara@bootlin.com \
--cc=kernel@pengutronix.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-iio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-stm32@st-md-mailman.stormreply.com \
--cc=mcoquelin.stm32@gmail.com \
--cc=o.rempel@pengutronix.de \
--cc=patrick.havelange@essensium.com \
--cc=syednwaris@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).