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>
* '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
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>
[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>
* '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.
...
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>
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>
This makes it consistent with other buses (platform, i2c, vio, ...). I'm
not sure why we use the prefixes, but there must be a reason.
This was easy enough to do it, and I did it.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Samuel Ortiz <sameo@openedhand.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Acked-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add two new spi_device.mode bits to accomodate more protocol options, and
pass them through to usermode drivers:
* SPI_NO_CS ... a second 3-wire variant, where the chipselect
line is removed instead of a data line; transfers are still
full duplex.
This obviously has STRONG protocol implications since the
chipselect transitions can't be used to synchronize state
transitions with the SPI master.
* SPI_READY ... defines open drain signal that's pulled low
to pause the clock. This defines a 5-wire variant (normal
4-wire SPI plus READY) and two 4-wire variants (READY plus
each of the 3-wire flavors).
Such hardware flow control can be a big win. There are ADC
converters and flash chips that expose READY signals, but not
many host controllers support it today.
The spi_bitbang code should be changed to use SPI_NO_CS instead of its
current nonportable hack. That's a mode most hardware can easily support
(unlike SPI_READY).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Paulraj, Sandeep" <s-paulraj@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Another step to removing ->ioctl and to removing the BKL
[dbrownell@users.sourceforge.net: take final step; BKL not needed]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch over to use the shiny new device_create_drvdata() call
instead of the original device_create() calls, so this continues
to work after device_create() is removed.
Note that this driver never had the race which motivated removing
the original call; it locked correctly.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This got broken by the recent "fix rmmod $spi_driver while spidev-user is
active". I tested the rmmod & write path but didn't check the read path.
I am sorry. The read logic changed and spidev_sync_read() +
spidev_sync_write() do not return zero on success anymore but the number
of bytes that has been transfered over the bus. This patch changes the
logic and copy_to_user() gets called again.
The write path returns the number of bytes which are written to the
underlying device what may be less than the requested size. This patch
makes the same change to the read path or else we request a read of 20
bytes, get 10, don't call copy to user and report to the user that we read
10 bytes.
[akpm@linux-foundation.org: remove test of known-to-be-zero local]
Signed-off-by: Sebastian Siewior <bigeasy@linutronix.de>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This addresses other oopsing paths in "spidev" by changing how it manages
refcounting. It decouples the lifecycle of the per-device data from the
class device (not just the spi device):
- Use class_{create,destroy} not class_{register,unregister}.
- Use device_{create,destroy} not device_{register,unregister}.
- Free the per-device data only when TWO conditions are true:
* Driver is unbound from underlying SPI device, and
* Device is no longer open (new)
Also, spi_{get,set}_drvdata not dev_{get,set}_drvdata for simpler code.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Sebastian Siewior <bigeasy@tglx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Somehow the spidev code forgot to include a critical mechanism: when the
underlying device is removed (e.g. spi_master rmmod), open file
descriptors must be prevented from issuing new I/O requests to that
device. On penalty of the oopsing reported by Sebastian Siewior
<bigeasy@tglx.de> ...
This is a partial fix, adding handshaking between the lower level (SPI
messaging) and the file operations using the spi_dev. (It also fixes an
issue where reads and writes didn't return the number of bytes sent or
received.)
There's still a refcounting issue to be addressed (separately).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Reported-by: Sebastian Siewior <bigeasy@tglx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use of ptrdiff_t in places like
- if (!access_ok(VERIFY_WRITE, u_tmp->rx_buf, u_tmp->len))
+ if (!access_ok(VERIFY_WRITE, (u8 __user *)
+ (ptrdiff_t) u_tmp->rx_buf,
+ u_tmp->len))
is wrong; for one thing, it's a bad C (it's what uintptr_t is for; in general
we are not even promised that ptrdiff_t is large enough to hold a pointer,
just enough to hold a difference between two pointers within the same object).
For another, it confuses the fsck out of sparse.
Use unsigned long or uintptr_t instead. There are several places misusing
ptrdiff_t; fixed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git rid of "warning: passing arg 2 of `access_ok' makes pointer from integer
without a cast" reported on SH ... most architectures use macros in that
test, SH uses inlined functions.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The spidev driver doesn't currently expose all SPI communications modes to
userspace. This passes them all through to the driver.
Two of them are potentially troublesome, in the sense that they could cause
hardware conflicts on shared busses. It might be appropriate to add some
privilege checks for for those modes.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Get rid of annoying GCC warning on 32-bit platforms.
drivers/spi/spidev.c: In function 'spidev_message':
drivers/spi/spidev.c:184: warning: cast to pointer from integer of different size
drivers/spi/spidev.c:216: warning: cast to pointer from integer of different size
The trick is to add an extra cast using "ptrdiff_t" to convert the u64 to
the correct size integer, and only then casting it into a "void *" pointer.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
'ioc' should be deallocated if __copy_from_user fails (found by Coverity
- CID 1644).
Signed-off-by: Florin Malita <fmalita@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Message size needs to be checked before copying, or bad things could
happen.
Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
find_first_zero_bit accepts number of bits, not longs.
Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a filesystem API for <linux/spi/spi.h> stack. The initial version of
this interface is purely synchronous.
dbrownell@users.sourceforge.net:
Cleaned up, bugfixed; much simplified; added preliminary documentation.
Works with mdev given CONFIG_SYSFS_DEPRECATED; and presumably udev.
Updated SPI_IOC_MESSAGE ioctl to full spi_message semantics, supporting
groups of one or more transfers (each of which may be full duplex if
desired).
This is marked as EXPERIMENTAL with an explicit disclaimer that the API
(notably the ioctls) is subject to change.
Signed-off-by: Andrea Paterniani <a.paterniani@swapp-eng.it>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
