From: Lars-Peter Clausen <lars@metafoo.de>
To: Alexandru Ardelean <alexandru.ardelean@analog.com>,
linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org
Cc: Michael.Hennerich@analog.com, jic23@kernel.org,
nuno.sa@analog.com, dragos.bogdan@analog.com
Subject: Re: [PATCH v6 20/24] iio: buffer: add ioctl() to support opening extra buffers for IIO device
Date: Sun, 28 Feb 2021 08:57:00 +0100 [thread overview]
Message-ID: <d0d2aece-e333-bd87-ad0a-60cf3e387ae4@metafoo.de> (raw)
In-Reply-To: <20210215104043.91251-21-alexandru.ardelean@analog.com>
On 2/15/21 11:40 AM, Alexandru Ardelean wrote:
> [...]
> /**
> * iio_buffer_wakeup_poll - Wakes up the buffer waitqueue
> * @indio_dev: The IIO device
> @@ -1343,6 +1371,96 @@ static void iio_buffer_unregister_legacy_sysfs_groups(struct iio_dev *indio_dev)
> kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
> }
>
> [...]
> +static long iio_device_buffer_getfd(struct iio_dev *indio_dev, unsigned long arg)
> +{
> + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
> + int __user *ival = (int __user *)arg;
> + struct iio_dev_buffer_pair *ib;
> + struct iio_buffer *buffer;
> + int fd, idx, ret;
> +
> + if (copy_from_user(&idx, ival, sizeof(idx)))
> + return -EFAULT;
If we only want to pass an int, we can pass that directly, no need to
pass it as a pointer.
int fd = arg;
> +
> + if (idx >= iio_dev_opaque->attached_buffers_cnt)
> + return -ENODEV;
> +
> + iio_device_get(indio_dev);
> +
> + buffer = iio_dev_opaque->attached_buffers[idx];
> +
> + if (test_and_set_bit(IIO_BUSY_BIT_POS, &buffer->flags)) {
> + ret = -EBUSY;
> + goto error_iio_dev_put;
> + }
> +
> + ib = kzalloc(sizeof(*ib), GFP_KERNEL);
> + if (!ib) {
> + ret = -ENOMEM;
> + goto error_clear_busy_bit;
> + }
> +
> + ib->indio_dev = indio_dev;
> + ib->buffer = buffer;
> +
> + fd = anon_inode_getfd("iio:buffer", &iio_buffer_chrdev_fileops,
> + ib, O_RDWR | O_CLOEXEC);
I wonder if we need to allow to pass flags, like e.g. O_NONBLOCK.
Something like
https://elixir.bootlin.com/linux/latest/source/fs/signalfd.c#L288
> + if (fd < 0) {
> + ret = fd;
> + goto error_free_ib;
> + }
> +
> + if (copy_to_user(ival, &fd, sizeof(fd))) {
> + put_unused_fd(fd);
> + ret = -EFAULT;
> + goto error_free_ib;
> + }
Here we copy back the fd, but also return it. Just return is probably
enough.
> +
> + return fd;
> +
> +error_free_ib:
> + kfree(ib);
> +error_clear_busy_bit:
> + clear_bit(IIO_BUSY_BIT_POS, &buffer->flags);
> +error_iio_dev_put:
> + iio_device_put(indio_dev);
> + return ret;
> +}
> [...]
> diff --git a/include/linux/iio/iio-opaque.h b/include/linux/iio/iio-opaque.h
> index b6ebc04af3e7..32addd5e790e 100644
> --- a/include/linux/iio/iio-opaque.h
> +++ b/include/linux/iio/iio-opaque.h
> @@ -9,6 +9,7 @@
> * @event_interface: event chrdevs associated with interrupt lines
> * @attached_buffers: array of buffers statically attached by the driver
> * @attached_buffers_cnt: number of buffers in the array of statically attached buffers
> + * @buffer_ioctl_handler: ioctl() handler for this IIO device's buffer interface
> * @buffer_list: list of all buffers currently attached
> * @channel_attr_list: keep track of automatically created channel
> * attributes
> @@ -28,6 +29,7 @@ struct iio_dev_opaque {
> struct iio_event_interface *event_interface;
> struct iio_buffer **attached_buffers;
> unsigned int attached_buffers_cnt;
> + struct iio_ioctl_handler *buffer_ioctl_handler;
Can we just embedded this struct so we do not have to
allocate/deallocate it?
> struct list_head buffer_list;
> struct list_head channel_attr_list;
> struct attribute_group chan_attr_group;
next prev parent reply other threads:[~2021-02-28 7:58 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-15 10:40 [PATCH v6 00/24] iio: core,buffer: add support for multiple IIO buffers per IIO device Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 01/24] iio: adc: ti_am335x_adc: remove omitted iio_kfifo_free() Alexandru Ardelean
2021-02-15 11:18 ` Jonathan Cameron
2021-02-15 10:40 ` [PATCH v6 02/24] iio: kfifo: add devm_iio_kfifo_buffer_setup() helper Alexandru Ardelean
2021-02-28 8:06 ` Lars-Peter Clausen
2021-02-28 17:45 ` Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 03/24] iio: make use of " Alexandru Ardelean
2021-02-15 12:11 ` Jonathan Cameron
2021-02-16 23:46 ` Gwendal Grignou
2021-02-18 8:22 ` Matt Ranostay
2021-02-18 13:25 ` Jonathan Cameron
2021-02-15 10:40 ` [PATCH v6 04/24] iio: accel: sca3000: use " Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 05/24] iio: kfifo: un-export devm_iio_kfifo_allocate() function Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 06/24] iio: buffer-dma,adi-axi-adc: introduce devm_iio_dmaengine_buffer_setup() Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 07/24] docs: ioctl-number.rst: reserve IIO subsystem ioctl() space Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 08/24] iio: core: register chardev only if needed Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 09/24] iio: core-trigger: make iio_device_register_trigger_consumer() an int return Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 10/24] iio: core: rework iio device group creation Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 11/24] iio: buffer: group attr count and attr alloc Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 12/24] iio: core: merge buffer/ & scan_elements/ attributes Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 13/24] iio: add reference to iio buffer on iio_dev_attr Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 14/24] iio: buffer: wrap all buffer attributes into iio_dev_attr Alexandru Ardelean
[not found] ` <CGME20210401073947eucas1p2c7f672475bce79dea00e9398cc562073@eucas1p2.samsung.com>
2021-04-01 7:39 ` Marek Szyprowski
2021-04-01 8:26 ` Jonathan Cameron
2021-04-01 11:10 ` Alexandru Ardelean
2022-09-09 8:12 ` Vaittinen, Matti
2022-09-19 8:52 ` [RFT] potential bug with IIO_CONST_ATTR usage with triggered buffers Vaittinen, Matti
2022-09-19 15:32 ` Jonathan Cameron
2022-09-19 17:18 ` Jonathan Cameron
2022-09-19 18:06 ` Vaittinen, Matti
2022-09-24 13:49 ` Jonathan Cameron
2022-09-25 13:28 ` Alexandru Ardelean
2022-10-06 8:33 ` Claudiu.Beznea
2021-02-15 10:40 ` [PATCH v6 15/24] iio: buffer: dmaengine: obtain buffer object from attribute Alexandru Ardelean
2021-02-15 12:44 ` Jonathan Cameron
2021-02-15 10:40 ` [PATCH v6 16/24] iio: core: wrap iio device & buffer into struct for character devices Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 17/24] iio: buffer: move __iio_buffer_free_sysfs_and_mask() before alloc Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 18/24] iio: dummy: iio_simple_dummy_buffer: use triggered buffer core calls Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 19/24] iio: buffer: introduce support for attaching more IIO buffers Alexandru Ardelean
2021-02-28 8:29 ` Lars-Peter Clausen
2021-02-28 17:46 ` Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 20/24] iio: buffer: add ioctl() to support opening extra buffers for IIO device Alexandru Ardelean
2021-02-28 7:57 ` Lars-Peter Clausen [this message]
2021-02-28 18:04 ` Alexandru Ardelean
2021-02-28 8:51 ` Lars-Peter Clausen
2021-02-28 14:34 ` Jonathan Cameron
2021-02-28 15:51 ` Lars-Peter Clausen
2021-02-28 17:27 ` Jonathan Cameron
2021-03-06 17:00 ` Alexandru Ardelean
2021-03-07 12:13 ` Jonathan Cameron
2021-03-13 18:46 ` Jonathan Cameron
2021-03-15 9:58 ` Sa, Nuno
2021-03-20 17:41 ` Jonathan Cameron
2021-03-21 17:37 ` Jonathan Cameron
2021-03-23 9:51 ` Alexandru Ardelean
2021-03-23 11:34 ` Jonathan Cameron
2021-03-24 9:10 ` Alexandru Ardelean
2021-03-27 12:00 ` Lars-Peter Clausen
2021-02-28 18:09 ` Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 21/24] iio: core: rename 'dev' -> 'indio_dev' in iio_device_alloc() Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 22/24] tools: iio: make iioutils_get_type() private in iio_utils Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 23/24] tools: iio: privatize globals and functions in iio_generic_buffer.c file Alexandru Ardelean
2021-02-15 10:40 ` [PATCH v6 24/24] tools: iio: convert iio_generic_buffer to use new IIO buffer API Alexandru Ardelean
2021-02-15 13:52 ` Jonathan Cameron
2021-02-15 13:57 ` [PATCH v6 00/24] iio: core,buffer: add support for multiple IIO buffers per IIO device Jonathan Cameron
2021-02-15 14:10 ` Alexandru Ardelean
2021-02-16 11:19 ` Jonathan Cameron
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