With this change, we create a new directory for the IIO device called
buffer0, under which both the old buffer/ and scan_elements/ are stored.
This is done to simplify the addition of multiple IIO buffers per IIO
device. Otherwise we would need to add a bufferX/ and scan_elementsX/
directory for each IIO buffer.
With the current way of storing attribute groups, we can't have directories
stored under each other (i.e. scan_elements/ under buffer/), so the best
approach moving forward is to merge their attributes.
The old/legacy buffer/ & scan_elements/ groups are not stored on the opaque
IIO device object. This way the IIO buffer can have just a single
attribute_group object, saving a bit of memory when adding multiple IIO
buffers.
Signed-off-by: Alexandru Ardelean <[email protected]>
---
drivers/iio/industrialio-buffer.c | 111 +++++++++++++++++++++++-------
include/linux/iio/buffer_impl.h | 9 +--
include/linux/iio/iio-opaque.h | 4 ++
3 files changed, 93 insertions(+), 31 deletions(-)
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 23f22be62cc7..f82decf92b7c 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -1252,8 +1252,68 @@ static struct attribute *iio_buffer_attrs[] = {
&dev_attr_data_available.attr,
};
+static int iio_buffer_register_legacy_sysfs_groups(struct iio_dev *indio_dev,
+ struct attribute **buffer_attrs,
+ int buffer_attrcount,
+ int scan_el_attrcount)
+{
+ struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
+ struct attribute_group *group;
+ int ret;
+
+ group = &iio_dev_opaque->legacy_buffer_group;
+
+ group->attrs = kcalloc(buffer_attrcount + 1,
+ sizeof(struct attribute *), GFP_KERNEL);
+ if (!group->attrs)
+ return -ENOMEM;
+
+ memcpy(group->attrs, buffer_attrs,
+ buffer_attrcount * sizeof(struct attribute *));
+ group->name = "buffer";
+
+ ret = iio_device_register_sysfs_group(indio_dev, group);
+ if (ret)
+ goto error_free_buffer_attrs;
+
+ group = &iio_dev_opaque->legacy_scan_el_group;
+
+ group->attrs = kcalloc(scan_el_attrcount + 1,
+ sizeof(struct attribute *), GFP_KERNEL);
+ if (!group->attrs) {
+ ret = -ENOMEM;
+ goto error_free_buffer_attrs;
+ }
+
+ memcpy(group->attrs, &buffer_attrs[buffer_attrcount],
+ scan_el_attrcount * sizeof(struct attribute *));
+ group->name = "scan_elements";
+
+ ret = iio_device_register_sysfs_group(indio_dev, group);
+ if (ret)
+ goto error_free_scan_el_attrs;
+
+ return 0;
+
+error_free_buffer_attrs:
+ kfree(iio_dev_opaque->legacy_buffer_group.attrs);
+error_free_scan_el_attrs:
+ kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
+
+ return ret;
+}
+
+void iio_buffer_unregister_legacy_sysfs_groups(struct iio_dev *indio_dev)
+{
+ struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
+
+ kfree(iio_dev_opaque->legacy_buffer_group.attrs);
+ kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
+}
+
static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
- struct iio_dev *indio_dev)
+ struct iio_dev *indio_dev,
+ int index)
{
struct iio_dev_attr *p;
struct attribute **attr;
@@ -1294,8 +1354,8 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
}
}
- attr = kcalloc(buffer_attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1,
- sizeof(struct attribute *), GFP_KERNEL);
+ attrn = buffer_attrcount + scan_el_attrcount + ARRAY_SIZE(iio_buffer_attrs);
+ attr = kcalloc(attrn + 1, sizeof(struct attribute *), GFP_KERNEL);
if (!attr) {
ret = -ENOMEM;
goto error_free_scan_mask;
@@ -1313,37 +1373,36 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
sizeof(struct attribute *) * buffer_attrcount);
buffer_attrcount += ARRAY_SIZE(iio_buffer_attrs);
- attr[buffer_attrcount] = NULL;
- buffer->buffer_group.name = "buffer";
- buffer->buffer_group.attrs = attr;
+ attrn = buffer_attrcount;
- ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group);
- if (ret)
+ list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
+ attr[attrn++] = &p->dev_attr.attr;
+
+ buffer->buffer_group.name = kasprintf(GFP_KERNEL, "buffer%d", index);
+ if (!buffer->buffer_group.name)
goto error_free_buffer_attrs;
- buffer->scan_el_group.name = iio_scan_elements_group_name;
+ buffer->buffer_group.attrs = attr;
- buffer->scan_el_group.attrs = kcalloc(scan_el_attrcount + 1,
- sizeof(buffer->scan_el_group.attrs[0]),
- GFP_KERNEL);
- if (buffer->scan_el_group.attrs == NULL) {
- ret = -ENOMEM;
- goto error_free_scan_mask;
- }
- attrn = 0;
+ ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group);
+ if (ret)
+ goto error_free_buffer_attr_group_name;
- list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
- buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr;
+ /* we only need to link the legacy buffer groups for the first buffer */
+ if (index > 0)
+ return 0;
- ret = iio_device_register_sysfs_group(indio_dev, &buffer->scan_el_group);
+ ret = iio_buffer_register_legacy_sysfs_groups(indio_dev, attr,
+ buffer_attrcount,
+ scan_el_attrcount);
if (ret)
- goto error_free_scan_el_attrs;
+ goto error_free_buffer_attr_group_name;
return 0;
-error_free_scan_el_attrs:
- kfree(buffer->scan_el_group.attrs);
+error_free_buffer_attr_group_name:
+ kfree(buffer->buffer_group.name);
error_free_buffer_attrs:
kfree(buffer->buffer_group.attrs);
error_free_scan_mask:
@@ -1372,14 +1431,14 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
if (!buffer)
return 0;
- return __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev);
+ return __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, 0);
}
static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer)
{
bitmap_free(buffer->scan_mask);
+ kfree(buffer->buffer_group.name);
kfree(buffer->buffer_group.attrs);
- kfree(buffer->scan_el_group.attrs);
iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
}
@@ -1390,6 +1449,8 @@ void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev)
if (!buffer)
return;
+ iio_buffer_unregister_legacy_sysfs_groups(indio_dev);
+
__iio_buffer_free_sysfs_and_mask(buffer);
}
diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h
index a63dc07b7350..3e555e58475b 100644
--- a/include/linux/iio/buffer_impl.h
+++ b/include/linux/iio/buffer_impl.h
@@ -100,14 +100,11 @@ struct iio_buffer {
/* @scan_el_dev_attr_list: List of scan element related attributes. */
struct list_head scan_el_dev_attr_list;
- /* @buffer_group: Attributes of the buffer group. */
- struct attribute_group buffer_group;
-
/*
- * @scan_el_group: Attribute group for those attributes not
- * created from the iio_chan_info array.
+ * @buffer_group: Attributes of the new buffer group.
+ * Includes scan elements attributes.
*/
- struct attribute_group scan_el_group;
+ struct attribute_group buffer_group;
/* @attrs: Standard attributes of the buffer. */
const struct attribute **attrs;
diff --git a/include/linux/iio/iio-opaque.h b/include/linux/iio/iio-opaque.h
index 8ba13a5c7af6..3e4c3cd248fd 100644
--- a/include/linux/iio/iio-opaque.h
+++ b/include/linux/iio/iio-opaque.h
@@ -14,6 +14,8 @@
* @ioctl_handlers: ioctl handlers registered with the core handler
* @groups: attribute groups
* @groupcounter: index of next attribute group
+ * @legacy_scan_el_group: attribute group for legacy scan elements attribute group
+ * @legacy_buffer_el_group: attribute group for legacy buffer attributes group
* @debugfs_dentry: device specific debugfs dentry
* @cached_reg_addr: cached register address for debugfs reads
* @read_buf: read buffer to be used for the initial reg read
@@ -28,6 +30,8 @@ struct iio_dev_opaque {
struct list_head ioctl_handlers;
const struct attribute_group **groups;
int groupcounter;
+ struct attribute_group legacy_scan_el_group;
+ struct attribute_group legacy_buffer_group;
#if defined(CONFIG_DEBUG_FS)
struct dentry *debugfs_dentry;
unsigned cached_reg_addr;
--
2.17.1
Hi Alexandru,
I love your patch! Perhaps something to improve:
[auto build test WARNING on iio/togreg]
[also build test WARNING on linux/master next-20210125]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Alexandru-Ardelean/iio-core-buffer-add-support-for-multiple-IIO-buffers-per-IIO-device/20210201-233550
base: https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
config: openrisc-randconfig-p001-20210201 (attached as .config)
compiler: or1k-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/418ff389a5a48a8a515a106734474e98d6d924ad
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Alexandru-Ardelean/iio-core-buffer-add-support-for-multiple-IIO-buffers-per-IIO-device/20210201-233550
git checkout 418ff389a5a48a8a515a106734474e98d6d924ad
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=openrisc
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
All warnings (new ones prefixed by >>):
>> drivers/iio/industrialio-buffer.c:1306:6: warning: no previous prototype for 'iio_buffer_unregister_legacy_sysfs_groups' [-Wmissing-prototypes]
1306 | void iio_buffer_unregister_legacy_sysfs_groups(struct iio_dev *indio_dev)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/iio/industrialio-buffer.c:1178:27: warning: 'iio_scan_elements_group_name' defined but not used [-Wunused-const-variable=]
1178 | static const char * const iio_scan_elements_group_name = "scan_elements";
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +/iio_buffer_unregister_legacy_sysfs_groups +1306 drivers/iio/industrialio-buffer.c
1305
> 1306 void iio_buffer_unregister_legacy_sysfs_groups(struct iio_dev *indio_dev)
1307 {
1308 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1309
1310 kfree(iio_dev_opaque->legacy_buffer_group.attrs);
1311 kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
1312 }
1313
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]
Hi Alexandru,
url: https://github.com/0day-ci/linux/commits/Alexandru-Ardelean/iio-core-buffer-add-support-for-multiple-IIO-buffers-per-IIO-device/20210201-233550
base: https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
config: arc-randconfig-m031-20210201 (attached as .config)
compiler: arc-elf-gcc (GCC) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
New smatch warnings:
drivers/iio/industrialio-buffer.c:1413 __iio_buffer_alloc_sysfs_and_mask() error: uninitialized symbol 'ret'.
vim +/ret +1413 drivers/iio/industrialio-buffer.c
e16e0a778fec8a Alexandru Ardelean 2020-09-17 1314 static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
418ff389a5a48a Alexandru Ardelean 2021-02-01 1315 struct iio_dev *indio_dev,
418ff389a5a48a Alexandru Ardelean 2021-02-01 1316 int index)
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1317 {
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1318 struct iio_dev_attr *p;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1319 struct attribute **attr;
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1320 int ret, i, attrn, scan_el_attrcount, buffer_attrcount;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1321 const struct iio_chan_spec *channels;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1322
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1323 buffer_attrcount = 0;
08e7e0adaa1720 Lars-Peter Clausen 2014-11-26 1324 if (buffer->attrs) {
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1325 while (buffer->attrs[buffer_attrcount] != NULL)
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1326 buffer_attrcount++;
08e7e0adaa1720 Lars-Peter Clausen 2014-11-26 1327 }
08e7e0adaa1720 Lars-Peter Clausen 2014-11-26 1328
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1329 scan_el_attrcount = 0;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1330 INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list);
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1331 channels = indio_dev->channels;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1332 if (channels) {
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1333 /* new magic */
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1334 for (i = 0; i < indio_dev->num_channels; i++) {
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1335 if (channels[i].scan_index < 0)
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1336 continue;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1337
ff3f7e049aef92 Alexandru Ardelean 2020-04-24 1338 ret = iio_buffer_add_channel_sysfs(indio_dev, buffer,
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1339 &channels[i]);
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1340 if (ret < 0)
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1341 goto error_cleanup_dynamic;
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1342 scan_el_attrcount += ret;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1343 if (channels[i].type == IIO_TIMESTAMP)
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1344 indio_dev->scan_index_timestamp =
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1345 channels[i].scan_index;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1346 }
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1347 if (indio_dev->masklength && buffer->scan_mask == NULL) {
3862828a903d3c Andy Shevchenko 2019-03-04 1348 buffer->scan_mask = bitmap_zalloc(indio_dev->masklength,
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1349 GFP_KERNEL);
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1350 if (buffer->scan_mask == NULL) {
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1351 ret = -ENOMEM;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1352 goto error_cleanup_dynamic;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1353 }
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1354 }
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1355 }
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1356
418ff389a5a48a Alexandru Ardelean 2021-02-01 1357 attrn = buffer_attrcount + scan_el_attrcount + ARRAY_SIZE(iio_buffer_attrs);
418ff389a5a48a Alexandru Ardelean 2021-02-01 1358 attr = kcalloc(attrn + 1, sizeof(struct attribute *), GFP_KERNEL);
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1359 if (!attr) {
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1360 ret = -ENOMEM;
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1361 goto error_free_scan_mask;
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1362 }
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1363
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1364 memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs));
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1365 if (!buffer->access->set_length)
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1366 attr[0] = &dev_attr_length_ro.attr;
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1367
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1368 if (buffer->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK)
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1369 attr[2] = &dev_attr_watermark_ro.attr;
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1370
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1371 if (buffer->attrs)
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1372 memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs,
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1373 sizeof(struct attribute *) * buffer_attrcount);
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1374
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1375 buffer_attrcount += ARRAY_SIZE(iio_buffer_attrs);
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1376
418ff389a5a48a Alexandru Ardelean 2021-02-01 1377 attrn = buffer_attrcount;
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1378
418ff389a5a48a Alexandru Ardelean 2021-02-01 1379 list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
418ff389a5a48a Alexandru Ardelean 2021-02-01 1380 attr[attrn++] = &p->dev_attr.attr;
418ff389a5a48a Alexandru Ardelean 2021-02-01 1381
418ff389a5a48a Alexandru Ardelean 2021-02-01 1382 buffer->buffer_group.name = kasprintf(GFP_KERNEL, "buffer%d", index);
418ff389a5a48a Alexandru Ardelean 2021-02-01 1383 if (!buffer->buffer_group.name)
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1384 goto error_free_buffer_attrs;
This needs to be "ret = -ENOMEM;"
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1385
418ff389a5a48a Alexandru Ardelean 2021-02-01 1386 buffer->buffer_group.attrs = attr;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1387
418ff389a5a48a Alexandru Ardelean 2021-02-01 1388 ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group);
418ff389a5a48a Alexandru Ardelean 2021-02-01 1389 if (ret)
418ff389a5a48a Alexandru Ardelean 2021-02-01 1390 goto error_free_buffer_attr_group_name;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1391
418ff389a5a48a Alexandru Ardelean 2021-02-01 1392 /* we only need to link the legacy buffer groups for the first buffer */
418ff389a5a48a Alexandru Ardelean 2021-02-01 1393 if (index > 0)
418ff389a5a48a Alexandru Ardelean 2021-02-01 1394 return 0;
2dca9525701e36 Alexandru Ardelean 2021-02-01 1395
418ff389a5a48a Alexandru Ardelean 2021-02-01 1396 ret = iio_buffer_register_legacy_sysfs_groups(indio_dev, attr,
418ff389a5a48a Alexandru Ardelean 2021-02-01 1397 buffer_attrcount,
418ff389a5a48a Alexandru Ardelean 2021-02-01 1398 scan_el_attrcount);
2dca9525701e36 Alexandru Ardelean 2021-02-01 1399 if (ret)
418ff389a5a48a Alexandru Ardelean 2021-02-01 1400 goto error_free_buffer_attr_group_name;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1401
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1402 return 0;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1403
418ff389a5a48a Alexandru Ardelean 2021-02-01 1404 error_free_buffer_attr_group_name:
418ff389a5a48a Alexandru Ardelean 2021-02-01 1405 kfree(buffer->buffer_group.name);
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1406 error_free_buffer_attrs:
e5d01923ab9239 Alexandru Ardelean 2021-02-01 1407 kfree(buffer->buffer_group.attrs);
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1408 error_free_scan_mask:
3862828a903d3c Andy Shevchenko 2019-03-04 1409 bitmap_free(buffer->scan_mask);
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1410 error_cleanup_dynamic:
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1411 iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1412
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 @1413 return ret;
d967cb6bd4e79c Lars-Peter Clausen 2014-11-26 1414 }
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]
On Mon, Feb 1, 2021 at 5:28 PM Alexandru Ardelean
<[email protected]> wrote:
>
> With this change, we create a new directory for the IIO device called
> buffer0, under which both the old buffer/ and scan_elements/ are stored.
>
> This is done to simplify the addition of multiple IIO buffers per IIO
> device. Otherwise we would need to add a bufferX/ and scan_elementsX/
> directory for each IIO buffer.
> With the current way of storing attribute groups, we can't have directories
> stored under each other (i.e. scan_elements/ under buffer/), so the best
> approach moving forward is to merge their attributes.
>
> The old/legacy buffer/ & scan_elements/ groups are not stored on the opaque
> IIO device object. This way the IIO buffer can have just a single
> attribute_group object, saving a bit of memory when adding multiple IIO
> buffers.
...
> +static int iio_buffer_register_legacy_sysfs_groups(struct iio_dev *indio_dev,
> + struct attribute **buffer_attrs,
> + int buffer_attrcount,
> + int scan_el_attrcount)
> +{
> + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
> + struct attribute_group *group;
> + int ret;
> +
> + group = &iio_dev_opaque->legacy_buffer_group;
> + group->attrs = kcalloc(buffer_attrcount + 1,
> + sizeof(struct attribute *), GFP_KERNEL);
> + if (!group->attrs)
> + return -ENOMEM;
> +
> + memcpy(group->attrs, buffer_attrs,
> + buffer_attrcount * sizeof(struct attribute *));
kmemdup() ?
Perhaps introduce kmemdup_array().
> + group->name = "buffer";
> +
> + ret = iio_device_register_sysfs_group(indio_dev, group);
> + if (ret)
> + goto error_free_buffer_attrs;
> +
> + group = &iio_dev_opaque->legacy_scan_el_group;
> + group->attrs = kcalloc(scan_el_attrcount + 1,
> + sizeof(struct attribute *), GFP_KERNEL);
> + if (!group->attrs) {
> + ret = -ENOMEM;
> + goto error_free_buffer_attrs;
> + }
> +
> + memcpy(group->attrs, &buffer_attrs[buffer_attrcount],
> + scan_el_attrcount * sizeof(struct attribute *));
Ditto.
> + group->name = "scan_elements";
> +
> + ret = iio_device_register_sysfs_group(indio_dev, group);
> + if (ret)
> + goto error_free_scan_el_attrs;
> +
> + return 0;
> +
> +error_free_buffer_attrs:
> + kfree(iio_dev_opaque->legacy_buffer_group.attrs);
> +error_free_scan_el_attrs:
> + kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
> +
> + return ret;
> +}
--
With Best Regards,
Andy Shevchenko
On Wed, Feb 3, 2021 at 12:04 PM Andy Shevchenko
<[email protected]> wrote:
>
> On Mon, Feb 1, 2021 at 5:28 PM Alexandru Ardelean
> <[email protected]> wrote:
> >
> > With this change, we create a new directory for the IIO device called
> > buffer0, under which both the old buffer/ and scan_elements/ are stored.
> >
> > This is done to simplify the addition of multiple IIO buffers per IIO
> > device. Otherwise we would need to add a bufferX/ and scan_elementsX/
> > directory for each IIO buffer.
> > With the current way of storing attribute groups, we can't have directories
> > stored under each other (i.e. scan_elements/ under buffer/), so the best
> > approach moving forward is to merge their attributes.
> >
> > The old/legacy buffer/ & scan_elements/ groups are not stored on the opaque
> > IIO device object. This way the IIO buffer can have just a single
> > attribute_group object, saving a bit of memory when adding multiple IIO
> > buffers.
>
> ...
>
> > +static int iio_buffer_register_legacy_sysfs_groups(struct iio_dev *indio_dev,
> > + struct attribute **buffer_attrs,
> > + int buffer_attrcount,
> > + int scan_el_attrcount)
> > +{
> > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
> > + struct attribute_group *group;
> > + int ret;
> > +
> > + group = &iio_dev_opaque->legacy_buffer_group;
>
> > + group->attrs = kcalloc(buffer_attrcount + 1,
> > + sizeof(struct attribute *), GFP_KERNEL);
> > + if (!group->attrs)
> > + return -ENOMEM;
> > +
> > + memcpy(group->attrs, buffer_attrs,
> > + buffer_attrcount * sizeof(struct attribute *));
>
> kmemdup() ?
> Perhaps introduce kmemdup_array().
doesn't add much benefit from what i can tell;
and it complicates things with the fact that we need to add the extra
null terminator element;
[1] if we kmemdup(buffer_attrcount + 1) , the copy an extra element we
don't need, which needs to be null-ed
>
> > + group->name = "buffer";
> > +
> > + ret = iio_device_register_sysfs_group(indio_dev, group);
> > + if (ret)
> > + goto error_free_buffer_attrs;
> > +
> > + group = &iio_dev_opaque->legacy_scan_el_group;
>
> > + group->attrs = kcalloc(scan_el_attrcount + 1,
> > + sizeof(struct attribute *), GFP_KERNEL);
> > + if (!group->attrs) {
> > + ret = -ENOMEM;
> > + goto error_free_buffer_attrs;
> > + }
> > +
> > + memcpy(group->attrs, &buffer_attrs[buffer_attrcount],
> > + scan_el_attrcount * sizeof(struct attribute *));
>
> Ditto.
continuing from [1]
here it may be worse, because kmemdup() would copy 1 element from
undefined memory;
>
> > + group->name = "scan_elements";
> > +
> > + ret = iio_device_register_sysfs_group(indio_dev, group);
> > + if (ret)
> > + goto error_free_scan_el_attrs;
> > +
> > + return 0;
> > +
> > +error_free_buffer_attrs:
> > + kfree(iio_dev_opaque->legacy_buffer_group.attrs);
> > +error_free_scan_el_attrs:
> > + kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
> > +
> > + return ret;
> > +}
>
> --
> With Best Regards,
> Andy Shevchenko
On Thu, Feb 4, 2021 at 3:41 PM Alexandru Ardelean
<[email protected]> wrote:
> On Wed, Feb 3, 2021 at 12:04 PM Andy Shevchenko
> <[email protected]> wrote:
> > On Mon, Feb 1, 2021 at 5:28 PM Alexandru Ardelean
> > <[email protected]> wrote:
...
> > > + group->attrs = kcalloc(buffer_attrcount + 1,
> > > + sizeof(struct attribute *), GFP_KERNEL);
> > > + if (!group->attrs)
> > > + return -ENOMEM;
> > > +
> > > + memcpy(group->attrs, buffer_attrs,
> > > + buffer_attrcount * sizeof(struct attribute *));
> >
> > kmemdup() ?
> > Perhaps introduce kmemdup_array().
>
> doesn't add much benefit from what i can tell;
> and it complicates things with the fact that we need to add the extra
> null terminator element;
> [1] if we kmemdup(buffer_attrcount + 1) , the copy an extra element we
> don't need, which needs to be null-ed
Ah, I see now. Thanks for pointing it out!
> > > + group->attrs = kcalloc(scan_el_attrcount + 1,
> > > + sizeof(struct attribute *), GFP_KERNEL);
> > > + if (!group->attrs) {
> > > + ret = -ENOMEM;
> > > + goto error_free_buffer_attrs;
> > > + }
> > > +
> > > + memcpy(group->attrs, &buffer_attrs[buffer_attrcount],
> > > + scan_el_attrcount * sizeof(struct attribute *));
> >
> > Ditto.
>
> continuing from [1]
> here it may be worse, because kmemdup() would copy 1 element from
> undefined memory;
--
With Best Regards,
Andy Shevchenko