linux/drivers/iio/industrialio-trigger.c

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/* The industrial I/O core, trigger handling functions
*
* Copyright (c) 2008 Jonathan Cameron
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/idr.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/list.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
#include "iio_core.h"
#include "iio_core_trigger.h"
#include <linux/iio/trigger_consumer.h>
/* RFC - Question of approach
* Make the common case (single sensor single trigger)
* simple by starting trigger capture from when first sensors
* is added.
*
* Complex simultaneous start requires use of 'hold' functionality
* of the trigger. (not implemented)
*
* Any other suggestions?
*/
static DEFINE_IDA(iio_trigger_ida);
/* Single list of all available triggers */
static LIST_HEAD(iio_trigger_list);
static DEFINE_MUTEX(iio_trigger_list_lock);
/**
* iio_trigger_read_name() - retrieve useful identifying name
* @dev: device associated with the iio_trigger
* @attr: pointer to the device_attribute structure that is
* being processed
* @buf: buffer to print the name into
*
* Return: a negative number on failure or the number of written
* characters on success.
*/
static ssize_t iio_trigger_read_name(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_trigger *trig = to_iio_trigger(dev);
return sprintf(buf, "%s\n", trig->name);
}
static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
static struct attribute *iio_trig_dev_attrs[] = {
&dev_attr_name.attr,
NULL,
};
ATTRIBUTE_GROUPS(iio_trig_dev);
static struct iio_trigger *__iio_trigger_find_by_name(const char *name);
int __iio_trigger_register(struct iio_trigger *trig_info,
struct module *this_mod)
{
int ret;
trig_info->owner = this_mod;
trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
if (trig_info->id < 0)
return trig_info->id;
/* Set the name used for the sysfs directory etc */
dev_set_name(&trig_info->dev, "trigger%ld",
(unsigned long) trig_info->id);
ret = device_add(&trig_info->dev);
if (ret)
goto error_unregister_id;
/* Add to list of available triggers held by the IIO core */
mutex_lock(&iio_trigger_list_lock);
if (__iio_trigger_find_by_name(trig_info->name)) {
pr_err("Duplicate trigger name '%s'\n", trig_info->name);
ret = -EEXIST;
goto error_device_del;
}
list_add_tail(&trig_info->list, &iio_trigger_list);
mutex_unlock(&iio_trigger_list_lock);
return 0;
error_device_del:
mutex_unlock(&iio_trigger_list_lock);
device_del(&trig_info->dev);
error_unregister_id:
ida_simple_remove(&iio_trigger_ida, trig_info->id);
return ret;
}
EXPORT_SYMBOL(__iio_trigger_register);
void iio_trigger_unregister(struct iio_trigger *trig_info)
{
mutex_lock(&iio_trigger_list_lock);
list_del(&trig_info->list);
mutex_unlock(&iio_trigger_list_lock);
ida_simple_remove(&iio_trigger_ida, trig_info->id);
/* Possible issue in here */
device_del(&trig_info->dev);
}
EXPORT_SYMBOL(iio_trigger_unregister);
int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig)
{
if (!indio_dev || !trig)
return -EINVAL;
mutex_lock(&indio_dev->mlock);
WARN_ON(indio_dev->trig_readonly);
indio_dev->trig = iio_trigger_get(trig);
indio_dev->trig_readonly = true;
mutex_unlock(&indio_dev->mlock);
return 0;
}
EXPORT_SYMBOL(iio_trigger_set_immutable);
/* Search for trigger by name, assuming iio_trigger_list_lock held */
static struct iio_trigger *__iio_trigger_find_by_name(const char *name)
{
struct iio_trigger *iter;
list_for_each_entry(iter, &iio_trigger_list, list)
if (!strcmp(iter->name, name))
return iter;
return NULL;
}
static struct iio_trigger *iio_trigger_acquire_by_name(const char *name)
{
struct iio_trigger *trig = NULL, *iter;
mutex_lock(&iio_trigger_list_lock);
list_for_each_entry(iter, &iio_trigger_list, list)
if (sysfs_streq(iter->name, name)) {
trig = iter;
iio_trigger_get(trig);
break;
}
mutex_unlock(&iio_trigger_list_lock);
return trig;
}
void iio_trigger_poll(struct iio_trigger *trig)
{
int i;
if (!atomic_read(&trig->use_count)) {
atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
if (trig->subirqs[i].enabled)
generic_handle_irq(trig->subirq_base + i);
else
iio_trigger_notify_done(trig);
}
}
}
EXPORT_SYMBOL(iio_trigger_poll);
irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
{
iio_trigger_poll(private);
return IRQ_HANDLED;
}
EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
void iio_trigger_poll_chained(struct iio_trigger *trig)
{
int i;
if (!atomic_read(&trig->use_count)) {
atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
if (trig->subirqs[i].enabled)
handle_nested_irq(trig->subirq_base + i);
else
iio_trigger_notify_done(trig);
}
}
}
EXPORT_SYMBOL(iio_trigger_poll_chained);
void iio_trigger_notify_done(struct iio_trigger *trig)
{
if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
trig->ops->try_reenable)
if (trig->ops->try_reenable(trig))
/* Missed an interrupt so launch new poll now */
iio_trigger_poll(trig);
}
EXPORT_SYMBOL(iio_trigger_notify_done);
/* Trigger Consumer related functions */
static int iio_trigger_get_irq(struct iio_trigger *trig)
{
int ret;
mutex_lock(&trig->pool_lock);
ret = bitmap_find_free_region(trig->pool,
CONFIG_IIO_CONSUMERS_PER_TRIGGER,
ilog2(1));
mutex_unlock(&trig->pool_lock);
if (ret >= 0)
ret += trig->subirq_base;
return ret;
}
static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
{
mutex_lock(&trig->pool_lock);
clear_bit(irq - trig->subirq_base, trig->pool);
mutex_unlock(&trig->pool_lock);
}
/* Complexity in here. With certain triggers (datardy) an acknowledgement
* may be needed if the pollfuncs do not include the data read for the
* triggering device.
* This is not currently handled. Alternative of not enabling trigger unless
* the relevant function is in there may be the best option.
*/
/* Worth protecting against double additions? */
static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
struct iio_poll_func *pf)
{
int ret = 0;
bool notinuse
= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
/* Prevent the module from being removed whilst attached to a trigger */
__module_get(pf->indio_dev->driver_module);
/* Get irq number */
pf->irq = iio_trigger_get_irq(trig);
if (pf->irq < 0)
goto out_put_module;
/* Request irq */
ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
pf->type, pf->name,
pf);
if (ret < 0)
goto out_put_irq;
/* Enable trigger in driver */
if (trig->ops && trig->ops->set_trigger_state && notinuse) {
ret = trig->ops->set_trigger_state(trig, true);
if (ret < 0)
goto out_free_irq;
}
iio: trigger: helpers to determine own trigger This adds a helper function to the IIO trigger framework: iio_trigger_using_own(): for an IIO device, this tells whether the device is using itself as a trigger. This is true if the indio device: (A) supplies a trigger and (B) has assigned its own buffer poll function to use this trigger. This helper function is good when constructing triggered, buffered drivers that can either use its own hardware *OR* an external trigger such as a HRTimer or even the trigger from a totally different sensor. Under such circumstances it is important to know for example if the timestamp from the same trigger hardware should be used when populating the buffer: if iio_trigger_using_own() is true, we can use this timestamp, else we need to pick a unique timestamp directly in the trigger handler. For this to work of course IIO devices registering hardware triggers must follow the convention to set the parent device properly, as as well as setting the parent of the IIO device itself. When a new poll function is attached, we check if the parent device of the IIO of the poll function is the same as the parent device of the trigger and in that case we conclude that the hardware is using itself as trigger. Cc: Giuseppe Barba <giuseppe.barba@st.com> Cc: Denis Ciocca <denis.ciocca@st.com> Cc: Crestez Dan Leonard <leonard.crestez@intel.com> Cc: Gregor Boirie <gregor.boirie@parrot.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-09-01 08:27:17 +00:00
/*
* Check if we just registered to our own trigger: we determine that
* this is the case if the IIO device and the trigger device share the
* same parent device.
*/
if (pf->indio_dev->dev.parent == trig->dev.parent)
trig->attached_own_device = true;
return ret;
out_free_irq:
free_irq(pf->irq, pf);
out_put_irq:
iio_trigger_put_irq(trig, pf->irq);
out_put_module:
module_put(pf->indio_dev->driver_module);
return ret;
}
static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
struct iio_poll_func *pf)
{
int ret = 0;
bool no_other_users
= (bitmap_weight(trig->pool,
CONFIG_IIO_CONSUMERS_PER_TRIGGER)
== 1);
if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
ret = trig->ops->set_trigger_state(trig, false);
if (ret)
return ret;
}
iio: trigger: helpers to determine own trigger This adds a helper function to the IIO trigger framework: iio_trigger_using_own(): for an IIO device, this tells whether the device is using itself as a trigger. This is true if the indio device: (A) supplies a trigger and (B) has assigned its own buffer poll function to use this trigger. This helper function is good when constructing triggered, buffered drivers that can either use its own hardware *OR* an external trigger such as a HRTimer or even the trigger from a totally different sensor. Under such circumstances it is important to know for example if the timestamp from the same trigger hardware should be used when populating the buffer: if iio_trigger_using_own() is true, we can use this timestamp, else we need to pick a unique timestamp directly in the trigger handler. For this to work of course IIO devices registering hardware triggers must follow the convention to set the parent device properly, as as well as setting the parent of the IIO device itself. When a new poll function is attached, we check if the parent device of the IIO of the poll function is the same as the parent device of the trigger and in that case we conclude that the hardware is using itself as trigger. Cc: Giuseppe Barba <giuseppe.barba@st.com> Cc: Denis Ciocca <denis.ciocca@st.com> Cc: Crestez Dan Leonard <leonard.crestez@intel.com> Cc: Gregor Boirie <gregor.boirie@parrot.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-09-01 08:27:17 +00:00
if (pf->indio_dev->dev.parent == trig->dev.parent)
trig->attached_own_device = false;
iio_trigger_put_irq(trig, pf->irq);
free_irq(pf->irq, pf);
module_put(pf->indio_dev->driver_module);
return ret;
}
irqreturn_t iio_pollfunc_store_time(int irq, void *p)
{
struct iio_poll_func *pf = p;
pf->timestamp = iio_get_time_ns(pf->indio_dev);
return IRQ_WAKE_THREAD;
}
EXPORT_SYMBOL(iio_pollfunc_store_time);
struct iio_poll_func
*iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
irqreturn_t (*thread)(int irq, void *p),
int type,
struct iio_dev *indio_dev,
const char *fmt,
...)
{
va_list vargs;
struct iio_poll_func *pf;
pf = kmalloc(sizeof *pf, GFP_KERNEL);
if (pf == NULL)
return NULL;
va_start(vargs, fmt);
pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
va_end(vargs);
if (pf->name == NULL) {
kfree(pf);
return NULL;
}
pf->h = h;
pf->thread = thread;
pf->type = type;
pf->indio_dev = indio_dev;
return pf;
}
EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
void iio_dealloc_pollfunc(struct iio_poll_func *pf)
{
kfree(pf->name);
kfree(pf);
}
EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
/**
* iio_trigger_read_current() - trigger consumer sysfs query current trigger
* @dev: device associated with an industrial I/O device
* @attr: pointer to the device_attribute structure that
* is being processed
* @buf: buffer where the current trigger name will be printed into
*
* For trigger consumers the current_trigger interface allows the trigger
* used by the device to be queried.
*
* Return: a negative number on failure, the number of characters written
* on success or 0 if no trigger is available
*/
static ssize_t iio_trigger_read_current(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
if (indio_dev->trig)
return sprintf(buf, "%s\n", indio_dev->trig->name);
return 0;
}
/**
* iio_trigger_write_current() - trigger consumer sysfs set current trigger
* @dev: device associated with an industrial I/O device
* @attr: device attribute that is being processed
* @buf: string buffer that holds the name of the trigger
* @len: length of the trigger name held by buf
*
* For trigger consumers the current_trigger interface allows the trigger
* used for this device to be specified at run time based on the trigger's
* name.
*
* Return: negative error code on failure or length of the buffer
* on success
*/
static ssize_t iio_trigger_write_current(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_trigger *oldtrig = indio_dev->trig;
struct iio_trigger *trig;
int ret;
mutex_lock(&indio_dev->mlock);
if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
mutex_unlock(&indio_dev->mlock);
return -EBUSY;
}
if (indio_dev->trig_readonly) {
mutex_unlock(&indio_dev->mlock);
return -EPERM;
}
mutex_unlock(&indio_dev->mlock);
trig = iio_trigger_acquire_by_name(buf);
if (oldtrig == trig) {
ret = len;
goto out_trigger_put;
}
if (trig && indio_dev->info->validate_trigger) {
ret = indio_dev->info->validate_trigger(indio_dev, trig);
if (ret)
goto out_trigger_put;
}
if (trig && trig->ops && trig->ops->validate_device) {
ret = trig->ops->validate_device(trig, indio_dev);
if (ret)
goto out_trigger_put;
}
indio_dev->trig = trig;
if (oldtrig) {
if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
iio_trigger_detach_poll_func(oldtrig,
indio_dev->pollfunc_event);
iio_trigger_put(oldtrig);
}
if (indio_dev->trig) {
if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
iio_trigger_attach_poll_func(indio_dev->trig,
indio_dev->pollfunc_event);
}
return len;
out_trigger_put:
iio: trigger: fix NULL pointer dereference in iio_trigger_write_current() In case oldtrig == trig == NULL (which happens when we set none trigger, when there is already none set) there is a NULL pointer dereference during iio_trigger_put(trig). Below is kernel output when this occurs: [ 26.741790] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 26.750179] pgd = cacc0000 [ 26.752936] [00000000] *pgd=8adc6835, *pte=00000000, *ppte=00000000 [ 26.759531] Internal error: Oops: 17 [#1] SMP ARM [ 26.764261] Modules linked in: usb_f_ncm u_ether usb_f_acm u_serial usb_f_fs libcomposite configfs evbug [ 26.773844] CPU: 0 PID: 152 Comm: synchro Not tainted 4.12.0-rc1 #2 [ 26.780128] Hardware name: Freescale i.MX6 Ultralite (Device Tree) [ 26.786329] task: cb1de200 task.stack: cac92000 [ 26.790892] PC is at iio_trigger_write_current+0x188/0x1f4 [ 26.796403] LR is at lock_release+0xf8/0x20c [ 26.800696] pc : [<c0736f34>] lr : [<c016efb0>] psr: 600d0013 [ 26.800696] sp : cac93e30 ip : cac93db0 fp : cac93e5c [ 26.812193] r10: c0e64fe8 r9 : 00000000 r8 : 00000001 [ 26.817436] r7 : cb190810 r6 : 00000010 r5 : 00000001 r4 : 00000000 [ 26.823982] r3 : 00000000 r2 : 00000000 r1 : cb1de200 r0 : 00000000 [ 26.830528] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [ 26.837683] Control: 10c5387d Table: 8acc006a DAC: 00000051 [ 26.843448] Process synchro (pid: 152, stack limit = 0xcac92210) [ 26.849475] Stack: (0xcac93e30 to 0xcac94000) [ 26.853857] 3e20: 00000001 c0736dac c054033c cae6b680 [ 26.862060] 3e40: cae6b680 00000000 00000001 cb3f8610 cac93e74 cac93e60 c054035c c0736db8 [ 26.870264] 3e60: 00000001 c054033c cac93e94 cac93e78 c029bf34 c0540348 00000000 00000000 [ 26.878469] 3e80: cb3f8600 cae6b680 cac93ed4 cac93e98 c029b320 c029bef0 00000000 00000000 [ 26.886672] 3ea0: 00000000 cac93f78 cb2d41fc caed3280 c029b214 cac93f78 00000001 000e20f8 [ 26.894874] 3ec0: 00000001 00000000 cac93f44 cac93ed8 c0221dcc c029b220 c0e1ca39 cb2d41fc [ 26.903079] 3ee0: cac93f04 cac93ef0 c0183ef0 c0183ab0 cb2d41fc 00000000 cac93f44 cac93f08 [ 26.911282] 3f00: c0225eec c0183ebc 00000001 00000000 c0223728 00000000 c0245454 00000001 [ 26.919485] 3f20: 00000001 caed3280 000e20f8 cac93f78 000e20f8 00000001 cac93f74 cac93f48 [ 26.927690] 3f40: c0223680 c0221da4 c0246520 c0245460 caed3283 caed3280 00000000 00000000 [ 26.935893] 3f60: 000e20f8 00000001 cac93fa4 cac93f78 c0224520 c02235e4 00000000 00000000 [ 26.944096] 3f80: 00000001 000e20f8 00000001 00000004 c0107f84 cac92000 00000000 cac93fa8 [ 26.952299] 3fa0: c0107de0 c02244e8 00000001 000e20f8 0000000e 000e20f8 00000001 fbad2484 [ 26.960502] 3fc0: 00000001 000e20f8 00000001 00000004 beb6b698 00064260 0006421c beb6b4b4 [ 26.968705] 3fe0: 00000000 beb6b450 b6f219a0 b6e2f268 800d0010 0000000e cac93ff4 cac93ffc [ 26.976896] Backtrace: [ 26.979388] [<c0736dac>] (iio_trigger_write_current) from [<c054035c>] (dev_attr_store+0x20/0x2c) [ 26.988289] r10:cb3f8610 r9:00000001 r8:00000000 r7:cae6b680 r6:cae6b680 r5:c054033c [ 26.996138] r4:c0736dac r3:00000001 [ 26.999747] [<c054033c>] (dev_attr_store) from [<c029bf34>] (sysfs_kf_write+0x50/0x54) [ 27.007686] r5:c054033c r4:00000001 [ 27.011290] [<c029bee4>] (sysfs_kf_write) from [<c029b320>] (kernfs_fop_write+0x10c/0x224) [ 27.019579] r7:cae6b680 r6:cb3f8600 r5:00000000 r4:00000000 [ 27.025271] [<c029b214>] (kernfs_fop_write) from [<c0221dcc>] (__vfs_write+0x34/0x120) [ 27.033214] r10:00000000 r9:00000001 r8:000e20f8 r7:00000001 r6:cac93f78 r5:c029b214 [ 27.041059] r4:caed3280 [ 27.043622] [<c0221d98>] (__vfs_write) from [<c0223680>] (vfs_write+0xa8/0x170) [ 27.050959] r9:00000001 r8:000e20f8 r7:cac93f78 r6:000e20f8 r5:caed3280 r4:00000001 [ 27.058731] [<c02235d8>] (vfs_write) from [<c0224520>] (SyS_write+0x44/0x98) [ 27.065806] r9:00000001 r8:000e20f8 r7:00000000 r6:00000000 r5:caed3280 r4:caed3283 [ 27.073582] [<c02244dc>] (SyS_write) from [<c0107de0>] (ret_fast_syscall+0x0/0x1c) [ 27.081179] r9:cac92000 r8:c0107f84 r7:00000004 r6:00000001 r5:000e20f8 r4:00000001 [ 27.088947] Code: 1a000009 e1a04009 e3a06010 e1a05008 (e5943000) [ 27.095244] ---[ end trace 06d1dab86d6e6bab ]--- To fix that problem call iio_trigger_put(trig) only when trig is not NULL. Fixes: d5d24bcc0a10 ("iio: trigger: close race condition in acquiring trigger reference") Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-05-18 07:12:06 +00:00
if (trig)
iio_trigger_put(trig);
return ret;
}
static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
iio_trigger_read_current,
iio_trigger_write_current);
static struct attribute *iio_trigger_consumer_attrs[] = {
&dev_attr_current_trigger.attr,
NULL,
};
static const struct attribute_group iio_trigger_consumer_attr_group = {
.name = "trigger",
.attrs = iio_trigger_consumer_attrs,
};
static void iio_trig_release(struct device *device)
{
struct iio_trigger *trig = to_iio_trigger(device);
int i;
if (trig->subirq_base) {
for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
irq_modify_status(trig->subirq_base + i,
IRQ_NOAUTOEN,
IRQ_NOREQUEST | IRQ_NOPROBE);
irq_set_chip(trig->subirq_base + i,
NULL);
irq_set_handler(trig->subirq_base + i,
NULL);
}
irq_free_descs(trig->subirq_base,
CONFIG_IIO_CONSUMERS_PER_TRIGGER);
}
kfree(trig->name);
kfree(trig);
}
static const struct device_type iio_trig_type = {
.release = iio_trig_release,
.groups = iio_trig_dev_groups,
};
static void iio_trig_subirqmask(struct irq_data *d)
{
struct irq_chip *chip = irq_data_get_irq_chip(d);
struct iio_trigger *trig
= container_of(chip,
struct iio_trigger, subirq_chip);
trig->subirqs[d->irq - trig->subirq_base].enabled = false;
}
static void iio_trig_subirqunmask(struct irq_data *d)
{
struct irq_chip *chip = irq_data_get_irq_chip(d);
struct iio_trigger *trig
= container_of(chip,
struct iio_trigger, subirq_chip);
trig->subirqs[d->irq - trig->subirq_base].enabled = true;
}
static struct iio_trigger *viio_trigger_alloc(const char *fmt, va_list vargs)
{
struct iio_trigger *trig;
int i;
trig = kzalloc(sizeof *trig, GFP_KERNEL);
if (!trig)
return NULL;
trig->dev.type = &iio_trig_type;
trig->dev.bus = &iio_bus_type;
device_initialize(&trig->dev);
mutex_init(&trig->pool_lock);
trig->subirq_base = irq_alloc_descs(-1, 0,
CONFIG_IIO_CONSUMERS_PER_TRIGGER,
0);
if (trig->subirq_base < 0)
goto free_trig;
trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
if (trig->name == NULL)
goto free_descs;
trig->subirq_chip.name = trig->name;
trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
irq_set_chip(trig->subirq_base + i, &trig->subirq_chip);
irq_set_handler(trig->subirq_base + i, &handle_simple_irq);
irq_modify_status(trig->subirq_base + i,
IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
}
get_device(&trig->dev);
return trig;
free_descs:
irq_free_descs(trig->subirq_base, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
free_trig:
kfree(trig);
return NULL;
}
struct iio_trigger *iio_trigger_alloc(const char *fmt, ...)
{
struct iio_trigger *trig;
va_list vargs;
va_start(vargs, fmt);
trig = viio_trigger_alloc(fmt, vargs);
va_end(vargs);
return trig;
}
EXPORT_SYMBOL(iio_trigger_alloc);
void iio_trigger_free(struct iio_trigger *trig)
{
if (trig)
put_device(&trig->dev);
}
EXPORT_SYMBOL(iio_trigger_free);
static void devm_iio_trigger_release(struct device *dev, void *res)
{
iio_trigger_free(*(struct iio_trigger **)res);
}
static int devm_iio_trigger_match(struct device *dev, void *res, void *data)
{
struct iio_trigger **r = res;
if (!r || !*r) {
WARN_ON(!r || !*r);
return 0;
}
return *r == data;
}
/**
* devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
* @dev: Device to allocate iio_trigger for
* @fmt: trigger name format. If it includes format
* specifiers, the additional arguments following
* format are formatted and inserted in the resulting
* string replacing their respective specifiers.
*
* Managed iio_trigger_alloc. iio_trigger allocated with this function is
* automatically freed on driver detach.
*
* If an iio_trigger allocated with this function needs to be freed separately,
* devm_iio_trigger_free() must be used.
*
* RETURNS:
* Pointer to allocated iio_trigger on success, NULL on failure.
*/
struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
const char *fmt, ...)
{
struct iio_trigger **ptr, *trig;
va_list vargs;
ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
GFP_KERNEL);
if (!ptr)
return NULL;
/* use raw alloc_dr for kmalloc caller tracing */
va_start(vargs, fmt);
trig = viio_trigger_alloc(fmt, vargs);
va_end(vargs);
if (trig) {
*ptr = trig;
devres_add(dev, ptr);
} else {
devres_free(ptr);
}
return trig;
}
EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
/**
* devm_iio_trigger_free - Resource-managed iio_trigger_free()
* @dev: Device this iio_dev belongs to
* @iio_trig: the iio_trigger associated with the device
*
* Free iio_trigger allocated with devm_iio_trigger_alloc().
*/
void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig)
{
int rc;
rc = devres_release(dev, devm_iio_trigger_release,
devm_iio_trigger_match, iio_trig);
WARN_ON(rc);
}
EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
static void devm_iio_trigger_unreg(struct device *dev, void *res)
{
iio_trigger_unregister(*(struct iio_trigger **)res);
}
/**
* __devm_iio_trigger_register - Resource-managed iio_trigger_register()
* @dev: device this trigger was allocated for
* @trig_info: trigger to register
* @this_mod: module registering the trigger
*
* Managed iio_trigger_register(). The IIO trigger registered with this
* function is automatically unregistered on driver detach. This function
* calls iio_trigger_register() internally. Refer to that function for more
* information.
*
* If an iio_trigger registered with this function needs to be unregistered
* separately, devm_iio_trigger_unregister() must be used.
*
* RETURNS:
* 0 on success, negative error number on failure.
*/
int __devm_iio_trigger_register(struct device *dev,
struct iio_trigger *trig_info,
struct module *this_mod)
{
struct iio_trigger **ptr;
int ret;
ptr = devres_alloc(devm_iio_trigger_unreg, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return -ENOMEM;
*ptr = trig_info;
ret = __iio_trigger_register(trig_info, this_mod);
if (!ret)
devres_add(dev, ptr);
else
devres_free(ptr);
return ret;
}
EXPORT_SYMBOL_GPL(__devm_iio_trigger_register);
/**
* devm_iio_trigger_unregister - Resource-managed iio_trigger_unregister()
* @dev: device this iio_trigger belongs to
* @trig_info: the trigger associated with the device
*
* Unregister trigger registered with devm_iio_trigger_register().
*/
void devm_iio_trigger_unregister(struct device *dev,
struct iio_trigger *trig_info)
{
int rc;
rc = devres_release(dev, devm_iio_trigger_unreg, devm_iio_trigger_match,
trig_info);
WARN_ON(rc);
}
EXPORT_SYMBOL_GPL(devm_iio_trigger_unregister);
iio: trigger: helpers to determine own trigger This adds a helper function to the IIO trigger framework: iio_trigger_using_own(): for an IIO device, this tells whether the device is using itself as a trigger. This is true if the indio device: (A) supplies a trigger and (B) has assigned its own buffer poll function to use this trigger. This helper function is good when constructing triggered, buffered drivers that can either use its own hardware *OR* an external trigger such as a HRTimer or even the trigger from a totally different sensor. Under such circumstances it is important to know for example if the timestamp from the same trigger hardware should be used when populating the buffer: if iio_trigger_using_own() is true, we can use this timestamp, else we need to pick a unique timestamp directly in the trigger handler. For this to work of course IIO devices registering hardware triggers must follow the convention to set the parent device properly, as as well as setting the parent of the IIO device itself. When a new poll function is attached, we check if the parent device of the IIO of the poll function is the same as the parent device of the trigger and in that case we conclude that the hardware is using itself as trigger. Cc: Giuseppe Barba <giuseppe.barba@st.com> Cc: Denis Ciocca <denis.ciocca@st.com> Cc: Crestez Dan Leonard <leonard.crestez@intel.com> Cc: Gregor Boirie <gregor.boirie@parrot.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-09-01 08:27:17 +00:00
bool iio_trigger_using_own(struct iio_dev *indio_dev)
{
return indio_dev->trig->attached_own_device;
}
EXPORT_SYMBOL(iio_trigger_using_own);
/**
* iio_trigger_validate_own_device - Check if a trigger and IIO device belong to
* the same device
* @trig: The IIO trigger to check
* @indio_dev: the IIO device to check
*
* This function can be used as the validate_device callback for triggers that
* can only be attached to their own device.
*
* Return: 0 if both the trigger and the IIO device belong to the same
* device, -EINVAL otherwise.
*/
int iio_trigger_validate_own_device(struct iio_trigger *trig,
struct iio_dev *indio_dev)
{
if (indio_dev->dev.parent != trig->dev.parent)
return -EINVAL;
return 0;
}
EXPORT_SYMBOL(iio_trigger_validate_own_device);
void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
{
indio_dev->groups[indio_dev->groupcounter++] =
&iio_trigger_consumer_attr_group;
}
void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
{
/* Clean up an associated but not attached trigger reference */
if (indio_dev->trig)
iio_trigger_put(indio_dev->trig);
}
int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
{
return iio_trigger_attach_poll_func(indio_dev->trig,
indio_dev->pollfunc);
}
EXPORT_SYMBOL(iio_triggered_buffer_postenable);
int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
{
return iio_trigger_detach_poll_func(indio_dev->trig,
indio_dev->pollfunc);
}
EXPORT_SYMBOL(iio_triggered_buffer_predisable);