Commit graph

70 commits

Author SHA1 Message Date
Linus Torvalds
090a81d876 Merge branch 'for-spi' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull spi uaccess delousing from Al Viro:
 "Getting rid of pointless __get_user() and friends in drivers/spi.

  [ the only reason it's on a separate branch is that I hoped it would
    be picked by spi folks; looks like mail asking them to grab it got
    lost and I hadn't followed up on that ]"

* 'for-spi' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  spidev: quit messing with access_ok()
2017-07-08 10:41:53 -07:00
Al Viro
251d59515f spidev: quit messing with access_ok()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-29 18:00:52 -04:00
Geliang Tang
f7929436a2 spi: spidev: use memdup_user
Use memdup_user() helper instead of open-coding to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-05-14 18:38:05 +09:00
Seraphime Kirkovski
76bf569466 spi: spidev: remove unused completion
This removes an unused completion from spidev_sync.

It was introduced in

	commit 25d5cb4b03 ("spi: remove some spidev oops-on-rmmod paths")

and it was no longer used after:

	commit 98d6f47958 ("spi: spidev: use spi_sync instead of spi_async")

Signed-off-by: Seraphime Kirkovski (Haapie) <kirkseraph@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-05-14 18:37:31 +09:00
Ben Whitten
91b4634632 spi: spidev: Add sx1301 to device tree compatibility list
Add entry for the semtech sx1301 baseband processor implementing a LoRa
concentrator IP.
At this time this chip requires an spidev userspace driver.

Signed-off-by: Ben Whitten <ben.whitten@lairdtech.com>
Signed-off-by: Steve deRosier <derosier@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-03-16 11:14:27 +00:00
Fabien Lahoudere
144235ea75 spi: spidev: Add device to spidev device tree compatibility list
Entries are needed in the spidev ID list to configure configure it from a
device tree. Add entry for the following device:
- "ge,achc" :  GE Healthcare USB Management Controller

The USB Management Controller does not expose USB to the host, but acts as
an offload engine, communicating with specific USB based data acquisition
devices which are connected to it, extracting the required data and
providing it to the host via other methods. SPI is used as an out-of-band
configuration channel.

Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-10-21 12:09:57 +01:00
Mika Westerberg
cf9f4327a3 spi: spidev: Add ACPI probing support
Some IoT and maker software stacks are using spidev to perform raw access
to the SPI bus instead of relying existing drivers provided by the kernel.
They then implement their own "drivers" in userspace on top of the spidev
raw interface. This is far from being an ideal solution but we do not want
to prevent using mainline Linux in these devices.

Now, it turns out that Windows has similar SPI devices than spidev which
allow raw access on the SPI bus to userspace programs as described in the
link below:

  https://msdn.microsoft.com/windows/hardware/drivers/spb/spi-tests-in-mitt

These SPI test devices are also meant to be used during development and
testing.

In order to allow usage of spidev for development and testing in Linux, add
those same ACPI IDs to the spidev driver (which is Linux counterpart of the
Windows SPI test devices), but complain loudly so that users know it is not
good idea to use it in production systems. Instead they should be using
proper drivers for peripherals connected to the SPI bus.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-07-04 16:28:52 +02:00
Mark Brown
4f9530705b Merge remote-tracking branches 'spi/topic/overlay', 'spi/topic/pxa2xx', 'spi/topic/s3c64xx', 'spi/topic/sh-msiof' and 'spi/topic/spidev' into spi-next 2016-01-11 16:48:35 +00:00
Mark Brown
56ea1075e7 spi: spidev: Hold spi_lock over all defererences of spi in release()
We use the spi_lock spinlock to protect against races between the device
being removed and file operations on the spidev.  This means that in the
removal path all references to the device need to be done under lock as
in removal we dropping references to the device.

Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-16 12:09:35 +00:00
Geert Uytterhoeven
f15c58410a spi: spidev: Use "%u" to format __u32
On 64-bit with CONFIG_SPI_DEBUG=y and #define VERBOSE:

    drivers/spi/spidev.c:287:3: warning: format '%zd' expects argument of type 'signed size_t', but argument 4 has type '__u32' [-Wformat=]

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-11-30 14:23:29 +00:00
Mark Brown
4c84518523 Merge remote-tracking branches 'spi/topic/omap-100k', 'spi/topic/omap-uwire', 'spi/topic/owner', 'spi/topic/pxa' and 'spi/topic/pxa2xx' into spi-next 2015-11-04 11:02:12 +00:00
Andrew F. Davis
3821a065f5 spi: Drop owner assignment from spi_drivers
An spi_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-28 10:30:17 +09:00
Mark Brown
711e020cae Merge remote-tracking branches 'spi/fix/spidev' and 'spi/fix/xtfpga' into spi-linus 2015-09-22 09:48:41 -07:00
Sudip Mukherjee
dd85ebf681 spi: spidev: fix possible NULL dereference
During the last close we are freeing spidev if spidev->spi is NULL, but
just before checking if spidev->spi is NULL we are dereferencing it.
Lets add a check there to avoid the NULL dereference.

Fixes: 9169051617 ("spi: spidev: Don't mangle max_speed_hz in underlying spi device")
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-09-11 13:26:38 +01:00
Mark Brown
c92ec7c7ae Merge remote-tracking branches 'spi/topic/s3c64xx', 'spi/topic/sg', 'spi/topic/sh-msiof', 'spi/topic/spidev' and 'spi/topic/stats' into spi-next 2015-08-31 14:45:41 +01:00
Colin Ian King
89a6356676 spi: spidev: fix inconsistent indenting
Fix inconsistent indenting in spidev_open, no functional change.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-08-04 17:51:32 +01:00
Fabio Estevam
ffe2288828 spi: spidev: Fix typo
Fix the typo in "compatible".

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-16 13:23:50 +01:00
Jiri Prchal
6fec919b61 spi: spidev: add compatible value for LTC2488
Since spidev is no more allowed to use in DT and is really loudly warned about
it I'd like to add this compatible value.
(Geert Uytterhoeven wrote: "Add the compatible value for your device to the
spidev_dt_ids[] array in drivers/spi/spidev.c.")

Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-07 13:34:22 +01:00
Mark Brown
fda052b0a5 Merge remote-tracking branches 'spi/topic/sirf', 'spi/topic/spidev' and 'spi/topic/zynq' into spi-next 2015-06-18 00:19:56 +01:00
Fabio Estevam
99472cc08a spi: spidev: Remove unneeded variable
Remove unneeded variable used to store return value.

The semantic patch that makes this change is available
in scripts/coccinelle/misc/returnvar.cocci.

More information about semantic patching is available at
http://coccinelle.lip6.fr/

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-11 16:14:57 +01:00
Martin Sperl
98d6f47958 spi: spidev: use spi_sync instead of spi_async
This has the benefit that the "optimization" of the framework in regards
to spi_sync will also benefit spidev users directly and allow running
spi transfers without a necessary context-switch to message-pump.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-04-23 10:34:39 +01:00
Mark Brown
956b200a84 spi: spidev: Warn loudly if instantiated from DT as "spidev"
Since spidev is a detail of how Linux controls a device rather than a
description of the hardware in the system we should never have a node
described as "spidev" in DT, any SPI device could be a spidev so this
is just not a useful description.

In order to help prevent users from writing such device trees generate a
warning if spidev is instantiated as a DT node without an ID in the match
table.

Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-27 16:43:03 -07:00
Ian Abbott
f20fbaad76 spi: spidev: fix possible arithmetic overflow for multi-transfer message
`spidev_message()` sums the lengths of the individual SPI transfers to
determine the overall SPI message length.  It restricts the total
length, returning an error if too long, but it does not check for
arithmetic overflow.  For example, if the SPI message consisted of two
transfers and the first has a length of 10 and the second has a length
of (__u32)(-1), the total length would be seen as 9, even though the
second transfer is actually very long.  If the second transfer specifies
a null `rx_buf` and a non-null `tx_buf`, the `copy_from_user()` could
overrun the spidev's pre-allocated tx buffer before it reaches an
invalid user memory address.  Fix it by checking that neither the total
nor the individual transfer lengths exceed the maximum allowed value.

Thanks to Dan Carpenter for reporting the potential integer overflow.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-23 14:00:51 -07:00
Ian Abbott
9a12bff7c3 spi: spidev: only use up TX/RX bounce buffer space when needed
This patch changes the way space is reserved in spidev's pre-allocated
TX and RX bounce buffers to avoid wasting space in the buffers for an
SPI message consisting of multiple, half-duplex transfers in different
directions.

Background:

spidev data structures have separate, pre-allocated TX and RX bounce
buffers (`spidev->tx_buffer` and `spidev->rx_buffer`) of fixed size
(`bufsiz`).  The `SPI_IOC_MESSAGE(N)` ioctl processing uses a kernel
copy of the N `struct spi_ioc_transfer` elements copied from the
userspace ioctl arg pointer.  In these elements: `.len` is the length of
transfer in bytes; `.rx_buf` is either a userspace pointer to a buffer
to copy the RX data to or is set to 0 to discard the data; and `.tx_buf`
is either a userspace pointer to TX data supplied by the user or is set
to 0 to transmit zeros for this transfer.

`spidev_message()` uses the array of N `struct spi_ioc_transfer`
elements to construct a kernel SPI message consisting of a `struct
spi_message` containing a linked list (allocated as an array) of N
`struct spi_transfer` elements.  This involves iterating through the
`struct spi_ioc_transfer` and `struct spi_transfer` elements (variables
`u_tmp` and `k_tmp` respectively).  Before the first iteration,
variables `tx_buf` and `rx_buf` point to the start of the TX and RX
bounce buffers `spidev->tx_buffer` and `spidev->rx_buffer` and variable
`total` is set to 0.  These variables keep track of the next available
space in the bounce buffers and the total length of the SPI message.
Each iteration checks that there is enough room left in the buffers for
the transfer.  If `u_tmp->rx_buf` is non-zero, `k_tmp->rx_buf` is set to
`rx_buf`, otherwise it remains set to NULL.  If `u_tmp->tx_buf` is
non-zero, `k_tmp->tx_buf` is set to `tx_buf` and the userspace TX data
copied there, otherwise it remains set to NULL.  The variables `total`,
`rx_buf` and `tx_buf` are advanced by the length of the transfer.

The "problem":

While iterating through the transfers, the local bounce buffer "free
space" pointer variables `tx_buf` and `rx_buf` are always advanced by
the length of the transfer.  If `u_tmp->rx_buf` is 0 (so `k_tmp->rx_buf`
is NULL), then `rx_buf` is advanced unnecessarily and that part of
`spidev->rx_buffer` is wasted.  Similarly, if `u_tmp->tx_buf` is 0 (so
`k_tmp->tx_buf` is NULL), part of `spidev->tx_buffer` is wasted.

What this patch does:

To avoid wasting space unnecessarily in the RX bounce buffer, only
advance `rx_buf` by the transfer length if `u_tmp->rx_buf` is non-zero.
Similarly, to avoid wasting space unnecessarily in the TX bounce buffer,
only advance `tx_buf` if `u_tmp->tx_buf is non-zero.  To avoid pointer
subtraction, use new variables `rx_total` and `tx_total` to keep track
of the amount of space allocated in each of the bounce buffers.  If
these exceed the available space, a `-EMSGSIZE` error will be returned.

Limit the total length of the transfers (tracked by variable `total`) to
`INT_MAX` instead of `bufsiz`, returning an `-EMSGSIZE` error if
exceeded.  The total length is returned by `spidev_message()` on success
and we want that to be non-negative.  The message size limits for the
`SPI_IOC_MESSAGE(N)` ioctl are now as follows:

(a) total length of transfers is <= INTMAX;
(b) total length of transfers with non-NULL rx_buf is <= bufsiz;
(c) total length of transfers with non-NULL tx_buf is <= bufsiz.

Some transfers may have NULL rx_buf and NULL tx_buf.

If the transfer is completed successfully by the SPI core,
`spidev_message()` iterates through the transfers to copy any RX data
from the bounce buffer back to userspace on those transfers where
`u_tmp->rx_buf` is non-zero.  The variable `rx_buf` is again used to
keep track of the corresponding positions in the bounce buffer.  Now it
is only advanced for those transfers that use the RX bounce buffer.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-24 10:38:25 +09:00
Mark Brown
30b9278bf5 Merge remote-tracking branches 'spi/topic/sirf', 'spi/topic/spidev', 'spi/topic/st-ssc' and 'spi/topic/ti-qspi' into spi-next 2015-02-08 11:16:58 +08:00
Ian Abbott
7782a1a948 spi: spidev: Convert buf pointers for 32-bit compat SPI_IOC_MESSAGE(n)
The SPI_IOC_MESSAGE(n) ioctl commands' argument points to an array of n
struct spi_ioc_transfer elements.  The spidev's compat_ioctl handler
just converts this pointer and passes it on to the unlocked_ioctl
handler to process it.

The tx_buf and rx_buf members of struct spi_ioc_transfer are of type
__u64 and hold pointer values.  A 32-bit userspace application running
in a 64-bit kernel might not have widened the 32-bit pointers correctly
for the kernel.  The application might have sign-extended the pointer to
when the kernel expects it to be zero-extended, or vice versa, leading
to an -EFAULT being returned by spidev_message() if the widened pointer
is invalid.

Handle the SPI_IOC_MESSAGE(n) ioctl commands specially in the
compat_ioctl handler, calling new function spidev_compat_ioctl_message()
to handle them.  This processes them in the same way as the
unlocked_ioctl handler except that it uses compat_ptr() to convert the
tx_buf and rx_buf members of each struct spi_ioc_transfer element.

To save code, factor out part of the unlocked_ioctl handler into a new
function spidev_get_ioc_message().  This checks the ioctl command code
is a valid SPI_IOC_MESSAGE(n), determines n and copies the array of n
struct spi_ioc_transfer elements from userspace into dynamically
allocated memory, returning either a pointer to the memory, an
ERR_PTR(-err) value, or NULL (for SPI_IOC_MESSAGE(0)).

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-02 19:57:19 +00:00
Jarkko Nikula
2c658e212c spi: Remove FSF mailing addresses
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-12-22 15:32:42 +00:00
Mark Brown
9169051617 spi: spidev: Don't mangle max_speed_hz in underlying spi device
Currently spidev allows callers to set the default speed by overriding the
max_speed_hz in the underlying device. This achieves the immediate goal but
is not what devices expect and can easily lead to userspace trying to set
unsupported speeds and succeeding, apart from anything else drivers can't
set a limit on the speed using max_speed_hz as they'd expect and any other
devices on the bus will be affected.

Instead store the default speed in the spidev struct and fill this in on
each transfer.

Signed-off-by: Mark Brown <broonie@kernel.org>
2014-11-11 18:01:28 +00:00
Ray Jui
865f6d1974 spi: spidev: Use separate TX and RX bounce buffers
By using separate TX and RX bounce buffers, we avoid potential cache
flush and invalidation sequence issue that may be encountered when a
single bounce buffer is shared between TX and RX

Signed-off-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: JD (Jiandong) Zheng <jdzheng@broadcom.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-10-13 13:07:12 +02:00
Geert Uytterhoeven
dc64d39b54 spi: spidev: Add support for Dual/Quad SPI Transfers
Add support for Dual/Quad SPI Transfers to the spidev API.
As this uses SPI mode bits that don't fit in a single byte, two new
ioctls (SPI_IOC_RD_MODE32 and SPI_IOC_WR_MODE32) are introduced.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-27 13:51:29 +09:00
Geert Uytterhoeven
e6456186ca spi: spidev: Restore all SPI mode flags on ioctl failure
In commit f477b7fb13 ("spi: DUAL and QUAD
support"), spi_device.mode was enlarged from 8 to 16 bits.

However, the spidev code still only saved 8 bits of data. If a spidev
SPI_IOC_WR_MODE or SPI_IOC_WR_LSB_FIRST request failed, only the lower 8
bits of the SPI mode were restored, inadvertently clearing the upper 8
bits, possibly disabling Quad or Dual SPI transfers for the device.

Save up to 32 bits to fix this.

For SPI_IOC_WR_MODE this is probably not so important, as it doesn't allow
setting Quad or Dual mode anyway, but SPI_IOC_WR_LSB_FIRST is used to just
set or clear a single bit.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-27 13:50:33 +09:00
Jingoo Han
95c63cfba7 spi: spidev: Fix checkpatch issue
Fix the following checkpatch warnings.

  WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
  WARNING: braces {} are not necessary for any arm of this statement

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-10-15 13:15:52 +01:00
Jingoo Han
91a92e12ba spi: spidev: remove unnecessary spi_set_drvdata()
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-09-17 00:19:50 +01:00
Rusty Russell
8c6ffba0ed PTR_RET is now PTR_ERR_OR_ZERO(): Replace most.
Sweep of the simple cases.

Cc: netdev@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-15 11:25:01 +09:30
Alexandru Gheorghiu
8179bb2655 spi/spidev: Use PTR_RET function
Replaced calls to IS_ERR and PTR_ERR with PTR_RET function.
Patch found using coccinelle.

Signed-off-by: Alexandru Gheorghiu <gheorghiuandru@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2013-04-01 14:32:32 +01:00
Grant Likely
fd4a319bc9 spi: Remove HOTPLUG section attributes
CONFIG_HOTPLUG is going away as an option.  As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.

Bill Pemberton has done most of the legwork on this series. I've used
his script to purge the attributes from the drivers/gpio tree.

Reported-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-12-07 17:06:43 +00:00
Maxime Ripard
8fad805bdc spi: spidev: Add Rohm DH2228FV DAC compatible string
Since we don't have a driver for it yet, use spidev instead.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-11-01 14:54:47 +00:00
Maxime Ripard
880cfd43ea spi: spidev: Add device tree bindings
This will allow to probe spidev from device tree by adding the
compatible string of each device to this array.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-11-01 14:54:47 +00:00
Grant Likely
ca632f5566 spi: reorganize drivers
Sort the SPI makefile and enforce the naming convention spi_*.c for
spi drivers.

This change also rolls the contents of atmel_spi.h into the .c file
since there is only one user of that particular include file.

v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be
      be the predominant pattern for subsystem prefixes.
    - Clean up filenames in Kconfig and header comment blocks

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
2011-06-06 01:16:30 -06:00
Bernhard Walle
7d48ec3698 spi/spidev: Add 32 bit compat ioctl()
Add the compat_ioctl for operations on /dev/spi* so that 32 bit
userspace applications can access SPI. As far as I can see all data
structure are already prepared for that, so no additional conversion has
to be done.

My use case is MIPS with N32 userspace ABI and toolchain, and that was
also the platform where I tested it successfully (Cavium Octeon).

Signed-off-by: Bernhard Walle <walle@corscience.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-02-03 09:55:43 -07:00
Uwe Kleine-König
b595076a18 tree-wide: fix comment/printk typos
"gadget", "through", "command", "maintain", "maintain", "controller", "address",
"between", "initiali[zs]e", "instead", "function", "select", "already",
"equal", "access", "management", "hierarchy", "registration", "interest",
"relative", "memory", "offset", "already",

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-11-01 15:38:34 -04:00
Arnd Bergmann
6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00
Linus Torvalds
bf931a01a2 Merge branch 'next-spi' of git://git.secretlab.ca/git/linux-2.6
* 'next-spi' of git://git.secretlab.ca/git/linux-2.6:
  spi: spi_txx9.c: use resource_size()
  spi: spi_sh_sci.c: use resource_size()
  spi: spi_mpc8xxx.c: use resource_size()
  spi: spi_bfin5xx.c: use resource_size()
  spi: atmel_spi.c: use resource_size()
  spi: Add s3c64xx SPI Controller driver
  atmel_spi: fix dma addr calculation for len > BUFFER_SIZE
  spi_s3c24xx: add FIQ pseudo-DMA support
  spi: controller driver for Designware SPI core
  spidev: add proper section markers
  spidev: use DECLARE_BITMAP instead of declaring the array
2009-12-17 15:59:05 -08:00
Mike Frysinger
db389b6143 spidev: add proper section markers
The driver already uses __devexit_p() in the structure, but looks like
actual __dev{init,exit} markings were forgotten.

The spidev_spi driver also needs renaming to include a "_driver" suffix to
avoid section mismatch warnings.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-12-17 08:39:12 -07:00
Thadeu Lima de Souza Cascardo
8ae1c92480 spidev: use DECLARE_BITMAP instead of declaring the array
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-12-17 08:39:12 -07:00
Linus Torvalds
478e4e9d7a Merge branch 'next-spi' of git://git.secretlab.ca/git/linux-2.6
* 'next-spi' of git://git.secretlab.ca/git/linux-2.6: (23 commits)
  spi: fix probe/remove section markings
  Add OMAP spi100k driver
  spi-imx: don't access struct device directly but use dev_get_platdata
  spi-imx: Add mx25 support
  spi-imx: use positive logic to distinguish cpu variants
  spi-imx: correct check for platform_get_irq failing
  ARM: NUC900: Add spi driver support for nuc900
  spi: SuperH MSIOF SPI Master driver V2
  spi: fix spidev compilation failure when VERBOSE is defined
  spi/au1550_spi: fix setupxfer not to override cfg with zeros
  spi/mpc8xxx: don't use __exit_p to wrap plat_mpc8xxx_spi_remove
  spi/i.MX: fix broken error handling for gpio_request
  spi/i.mx: drain MXC SPI transfer buffer when probing device
  MAINTAINERS: add SPI co-maintainer.
  spi/xilinx_spi: fix incorrect casting
  spi/mpc52xx-spi: minor cleanups
  xilinx_spi: add a platform driver using the xilinx_spi common module.
  xilinx_spi: add support for the DS570 IP.
  xilinx_spi: Switch to iomem functions and support little endian.
  xilinx_spi: Split into of driver and generic part.
  ...
2009-12-14 10:22:11 -08:00
Linus Torvalds
4ef58d4e2a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits)
  tree-wide: fix misspelling of "definition" in comments
  reiserfs: fix misspelling of "journaled"
  doc: Fix a typo in slub.txt.
  inotify: remove superfluous return code check
  hdlc: spelling fix in find_pvc() comment
  doc: fix regulator docs cut-and-pasteism
  mtd: Fix comment in Kconfig
  doc: Fix IRQ chip docs
  tree-wide: fix assorted typos all over the place
  drivers/ata/libata-sff.c: comment spelling fixes
  fix typos/grammos in Documentation/edac.txt
  sysctl: add missing comments
  fs/debugfs/inode.c: fix comment typos
  sgivwfb: Make use of ARRAY_SIZE.
  sky2: fix sky2_link_down copy/paste comment error
  tree-wide: fix typos "couter" -> "counter"
  tree-wide: fix typos "offest" -> "offset"
  fix kerneldoc for set_irq_msi()
  spidev: fix double "of of" in comment
  comment typo fix: sybsystem -> subsystem
  ...
2009-12-09 19:43:33 -08:00
Florian Fainelli
41df70d9ac spi: fix spidev compilation failure when VERBOSE is defined
When VERBOSE is defined in the spidev module, the compilation
will throw an error on 'spi' not being defined:

CC [M]  drivers/spi/spidev.o
drivers/spi/spidev.c: In function 'spidev_message':
drivers/spi/spidev.c:266: error: 'spi' undeclared (first use in this function)
drivers/spi/spidev.c:266: error: (Each undeclared identifier is reported only once
drivers/spi/spidev.c:266: error: for each function it appears in.)

instead of using spi-> we should actually use spidev->spi.
This patch fixes the build failure.

Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-12-08 18:48:17 -07:00
Thadeu Lima de Souza Cascardo
137f1188ef spidev: fix double "of of" in comment
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-04 15:39:50 +01:00
Thomas Gleixner
4c2aedc254 spi: Remove BKL from spidev_open
The BKL was added there with the big pushdown. Remove it as the code
is serialized already.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20091010153349.318535932@linutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-10-14 17:36:48 +02:00