Commit Graph

63 Commits

Author SHA1 Message Date
Sjur Brændeland
1c385f1fdf caif-hsi: Replace platform device with ops structure.
Remove use of struct platform_device, and replace it with
struct cfhsi_ops. Updated variable names in the same
spirit:
cfhsi_get_dev to cfhsi_get_ops,
cfhsi->dev to cfhsi->ops and,
cfhsi->dev.drv to cfhsi->ops->cb_ops.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-25 16:44:12 -07:00
Sjur Brændeland
c412540063 caif-hsi: Add rtnl support
Add RTNL support for managing the caif hsi interface.
The HSI HW interface is no longer registering as a device,
instead we use symbol_get to get hold of the HSI API.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-25 16:44:12 -07:00
Sjur Brændeland
b42f7b5cfd caif-hsi: Remove uncecessary assignments
Remove assignment at declaration when not needed.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericssion.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-25 16:44:12 -07:00
Sjur Brændeland
90de9bab91 caif-hsi: Use netdev_X instead of dev_X for printing
Replace dev_X with the corresponding netdev_X print
function when applicable.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericssion.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-25 16:44:12 -07:00
Kim Lilliestierna XX
a5c96b518c caif-hsi: changed test on aggregation_timeout
Aggregation_timeout is an unsigned long,
a test for less than zero can never become true,
compare with zero instead.

Signed-off-by: Kim Lilliestierna <kim.xx.lilliestierna@stericsson.com>
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-25 16:44:12 -07:00
Kim Lilliestierna XX
4e7bb59d49 caif-hsi: Removed dead code
Simplify logic and remove dead code.

Signed-off-by: Kim Lilliestierna <kim.xx.lilliestierna@stericsson.com>
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-25 16:44:12 -07:00
Arnd Bergmann
6e4a76291e caif: include linux/io.h
The caif_shmcore requires io.h in order to use ioremap, so include that
explicitly to compile in all configurations.

Also add a note about the use of ioremap(), which is not a proper way
to map a DMA buffer into kernel space. It's not completely clear what
the intention is for using ioremap, but it is clear that the result
of ioremap must not simply be accessed using kernel pointers but
should use readl/writel or memcopy_{to,from}io. Assigning the result
of ioremap to a regular pointer that can also be set to something
else is not ok.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-21 15:28:47 -04:00
sjur.brandeland@stericsson.com
39abbaef19 caif-hsi: Postpone init of HSI until open()
Do the initialization of the HSI interface when the
interface is opened, instead of upon registration.
When the interface is closed the HSI interface is
de-initialized, allowing other modules to use the
HSI interface.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-13 11:37:37 -04:00
sjur.brandeland@stericsson.com
2df1fe7f10 caif-hsi: Remove stop/start of queue.
CAIF HSI is currently a virtual device. Stopping/starting the
queues is wrong on a virtual device.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-13 11:37:36 -04:00
Dmitry Tarnyagin
ece367d53a caif-hsi: robust frame aggregation for HSI
Implement aggregation algorithm, combining more data into a single
HSI transfer. 4 different traffic categories are supported:
 1. TC_PRIO_CONTROL .. TC_PRIO_MAX (CTL)
 2. TC_PRIO_INTERACTIVE            (VO)
 3. TC_PRIO_INTERACTIVE_BULK       (VI)
 4. TC_PRIO_BESTEFFORT, TC_PRIO_BULK, TC_PRIO_FILLER (BEBK)

Signed-off-by: Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-13 11:37:36 -04:00
Kim Lilliestierna XX
d62f8dbb5b caif_hsi: use dev_dbg not dev_err for reporting
Use dev_dbg instead of dev_err for reporting in cfhsi_wakeup_cb.

Signed-off-by: Kim Lilliestierna <kim.xx.lilliestierna@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-13 11:01:44 -04:00
sjur.brandeland@stericsson.com
5f614e6b70 caif-hsi: Free flip_buffer at shutdown
Fix memory leak of RX flip-buffer.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-13 11:01:44 -04:00
Stephen Boyd
234e340582 simple_open: automatically convert to simple_open()
Many users of debugfs copy the implementation of default_open() when
they want to support a custom read/write function op.  This leads to a
proliferation of the default_open() implementation across the entire
tree.

Now that the common implementation has been consolidated into libfs we
can replace all the users of this function with simple_open().

This replacement was done with the following semantic patch:

<smpl>
@ open @
identifier open_f != simple_open;
identifier i, f;
@@
-int open_f(struct inode *i, struct file *f)
-{
(
-if (i->i_private)
-f->private_data = i->i_private;
|
-f->private_data = i->i_private;
)
-return 0;
-}

@ has_open depends on open @
identifier fops;
identifier open.open_f;
@@
struct file_operations fops = {
...
-.open = open_f,
+.open = simple_open,
...
};
</smpl>

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-05 15:25:50 -07:00
David S. Miller
b2d3298e09 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-03-09 14:34:20 -08:00
Sjur Brændeland
34efc283a5 caif-hsi: Set default MTU to 4096
Default MTU for CAIF HSI was wrongly set to 15 * 4092 bytes.
The patch sets default MTU size to 4096.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-06 16:27:45 -05:00
sjur.brandeland@stericsson.com
332ad43f19 caif-hsi: Add RX flip buffer
Implement RX flip buffer in the cfhsi_rx_done function,
piggy-backed frames is also supported.
This gives a significant performance gain for CAIF over HSI.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-04 16:06:28 -05:00
Rusty Russell
eb93992207 module_param: make bool parameters really bool (net & drivers/net)
module_param(bool) used to counter-intuitively take an int.  In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

It's time to remove the int/unsigned int option.  For this version
it'll simply give a warning, but it'll break next kernel version.

(Thanks to Joe Perches for suggesting coccinelle for 0/1 -> true/false).

Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-19 22:27:29 -05:00
Roar Førde
f84ea779c2 caif: Replace BUG_ON with WARN_ON.
BUG_ON is too strict in a number of circumstances,
use WARN_ON instead. Protocol errors should not halt the system.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-06 17:21:47 -05:00
sjur.brandeland@stericsson.com
095d2a71e5 caif-shm: Bugfixes for caif_shmcore.c
Various bugfixes for caif_shmcore.c:
- fix deadlocks due to improper usage of spin-lock
- add missing spin-lock init
- don't call dev_kfree_skb() with irqs disabled,
  use dev_kfree_skb_irq() instead.
- fix potential skb null pointer de-reference.

Squashed original patches from:
Rabin Vincent <rabin.vincent@stericsson.com>
Durga Prasada Rao BATHINA <durgaprasadarao.b@stericcson.com>
Arun Murthy <arun.murthy@stericsson.com>
Bibek Basu <bibek.basu@stericsson.com>

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-06 17:21:47 -05:00
Christian Auby
1e226773c7 caif-hsi: Remove wake line modification when flushing FIFO
Raising wake before flushing FIFO and lowering it after caused a
spike on AC wake that were sometimes detected and acted upon by the
modem. Fixed this by remove wake line modification when flushing FIFO.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-06 17:21:46 -05:00
Erwan Bracq
d5f43c1ea4 caif-spi: Bugfix for dump upon device removal
Fix dump upon device removal, by moving deinitialization from
platform-device-remove to network-interface-uninit.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-06 13:34:12 -05:00
Daniel Martensson
5ea2ef5f8b caif-hsi: Added recovery check of CA wake status.
Added recovery check of CA wake status in case of wake up timeout.
Added check of CA wake status in case of wake down timeout.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19 03:25:43 -04:00
Daniel Martensson
5bbed92d3d caif-hsi: Added sanity check for length of CAIF frames
Added sanity check for length of CAIF frames, and tear down of
CAIF link-layer device upon protocol error.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19 03:25:42 -04:00
Dmitry Tarnyagin
28bd204942 caif-hsi: Make inactivity timeout configurable.
CAIF HSI uses a timer for inactivity. Upon timeout HSI-wake signaling
is initiated to allow power-down of the HSI block.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19 03:25:42 -04:00
Daniel Martensson
ca63f8c751 caif-hsi: HSI-Platform device register and unregisters itself
Platform device is no longer removed from caif_hsi at shutdown.
The HSI-platform device must do it's own registration and unregistration.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19 03:25:41 -04:00
Daniel Martensson
687b13e98a caif-hsi: Making read and writes asynchronous.
Some platforms do not allow to put HSI block into low-power
mode when FIFO is not empty. The patch flushes (by reading)
FIFO at wake down sequence. Asynchronous read and write is
implemented for that. As a side effect this will also greatly
improve performance.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19 03:25:41 -04:00
Dmitry Tarnyagin
73033c987a caif-hsi: Fix for wakeup condition problem
Under stressed conditions a race could happen when del_timer_sync() was called
from softirq context at the same time when mod_timer_pending() for the same
timer was called from the workqueue. This leaded to a state mismatch in the
CAIF HSI driver and following unexpected link wakeup procedure.

The fix puts del_timer_sync() and mod_timer_pending() calls under a spin lock
to protect against the race condition.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19 03:25:41 -04:00
Dmitry Tarnyagin
fe47f12508 caif-hsi: Fixing a race condition in the caif_hsi code
cfhsi->tx_state was not protected by a spin lock. TX soft-irq could interrupt
cfhsi_tx_done_work work leading to inconsistent state of the driver.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19 03:25:41 -04:00
sjur.brandeland@stericsson.com
94230febe4 caif-hsi: HSI Fix uninitialized data in HSI header
CAIF HSI header may be uninitialized and cause last message to
be repeated if transmit size is ~86 bytes long.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19 03:25:40 -04:00
Joe Perches
7ac2ed0cee caif: Remove OOM messages, use kzalloc
Remove per site OOM messages because they duplicate
the generic mm subsystem OOM message.

Use kzalloc instead of kmalloc/memset
when next to the OOM message removals.

Reduces object size (allyesconfig ~2%)

$ size -t drivers/net/caif/built-in.o.old net/caif/built-in.o.old
   text	   data	    bss	    dec	    hex	filename
  32297	    700	   8224	  41221	   a105	drivers/net/caif/built-in.o.old
  72159	   1317	  20552	  94028	  16f4c	net/caif/built-in.o.old
 104456	   2017	  28776	 135249	  21051	(TOTALS)
$ size -t drivers/net/caif/built-in.o.new net/caif/built-in.o.new
   text	   data	    bss	    dec	    hex	filename
  31975	    700	   8184	  40859	   9f9b	drivers/net/caif/built-in.o.new
  70748	   1317	  20152	  92217	  16839	net/caif/built-in.o.new
 102723	   2017	  28336	 133076	  207d4	(TOTALS)

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-28 17:16:13 -04:00
Shan Wei
fa917ff739 net: fix warning of versioncheck
net-next-2.6/drivers/net/bnx2x/bnx2x_sp.c: 19 linux/version.h not needed.
net-next-2.6/drivers/net/caif/caif_hsi.c: 9 linux/version.h not needed.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-07 00:26:31 -07:00
Joe Perches
864834f935 caif: Fix recieve/receive typo
Just spelling fixes.

Actually, a twofer with vaiables/variables as well.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-29 05:52:03 -07:00
Jesper Juhl
95cb3656c0 net: Remove unneeded version.h includes from drivers/net/
It was pointed out by 'make versioncheck' that some includes of
linux/version.h are not needed in drivers/net/.
This patch removes them.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-24 02:40:08 -07:00
Joe Perches
43d620c829 drivers/net: Remove casts of void *
Unnecessary casts of void * clutter the code.

These are the remainder casts after several specific
patches to remove netdev_priv and dev_priv.

Done via coccinelle script (and a little editing):

$ cat cast_void_pointer.cocci
@@
type T;
T *pt;
void *pv;
@@

- pt = (T *)pv;
+ pt = pv;

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Acked-By: Chris Snook <chris.snook@gmail.com>
Acked-by: Jon Mason <jdmason@kudzu.us>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David Dillow <dave@thedillows.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-21 15:48:29 -07:00
Alexey Dobriyan
a6b7a40786 net: remove interrupt.h inclusion from netdevice.h
* remove interrupt.g inclusion from netdevice.h -- not needed
* fixup fallout, add interrupt.h and hardirq.h back where needed.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-06 22:55:11 -07:00
David S. Miller
e990b37b90 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-06-04 13:38:31 -07:00
Linus Torvalds
55db4c64ed Revert "tty: make receive_buf() return the amout of bytes received"
This reverts commit b1c43f82c5.

It was broken in so many ways, and results in random odd pty issues.

It re-introduced the buggy schedule_work() in flush_to_ldisc() that can
cause endless work-loops (see commit a5660b41af: "tty: fix endless
work loop when the buffer fills up").

It also used an "unsigned int" return value fo the ->receive_buf()
function, but then made multiple functions return a negative error code,
and didn't actually check for the error in the caller.

And it didn't actually work at all.  BenH bisected down odd tty behavior
to it:
  "It looks like the patch is causing some major malfunctions of the X
   server for me, possibly related to PTYs.  For example, cat'ing a
   large file in a gnome terminal hangs the kernel for -minutes- in a
   loop of what looks like flush_to_ldisc/workqueue code, (some ftrace
   data in the quoted bits further down).

   ...

   Some more data: It -looks- like what happens is that the
   flush_to_ldisc work queue entry constantly re-queues itself (because
   the PTY is full ?) and the workqueue thread will basically loop
   forver calling it without ever scheduling, thus starving the consumer
   process that could have emptied the PTY."

which is pretty much exactly the problem we fixed in a5660b41af.

Milton Miller pointed out the 'unsigned int' issue.

Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reported-by: Milton Miller <miltonm@bga.com>
Cc: Stefan Bigler <stefan.bigler@keymile.com>
Cc: Toby Gray <toby.gray@realvnc.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-04 06:33:24 +09:00
Dmitry.Tarnyagin
40d69043fc caif: Add CAIF HSI Link layer driver
This patch introduces the CAIF HSI Protocol Driver for the
CAIF Link Layer.

This driver implements a platform driver to accommodate for a
platform specific HSI devices. A general platform driver is not
possible as there are no HSI side Kernel API defined.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-01 21:15:38 -07:00
Felipe Balbi
b1c43f82c5 tty: make receive_buf() return the amout of bytes received
it makes it simpler to keep track of the amount of
bytes received and simplifies how flush_to_ldisc counts
the remaining bytes. It also fixes a bug of lost bytes
on n_tty when flushing too many bytes via the USB
serial gadget driver.

Tested-by: Stefan Bigler <stefan.bigler@keymile.com>
Tested-by: Toby Gray <toby.gray@realvnc.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-22 17:31:53 -07:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
matt mooney
5a8b7cdc74 net: change to new flag variable
Replace EXTRA_CFLAGS with ccflags-y.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-03-17 14:05:35 +01:00
Russell King
cde9efef40 Merge branch 'ux500-core' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-stericsson into devel-stable 2011-01-03 10:31:58 +00:00
Linus Walleij
11c8ea81cc ux500: rename modem IRQ and MBOX files
Suffix the U5500 modem IRQ and MBOX files with *-db5500* so that
we clearly know the SoC they belong to, in line with the rest of
the files in mach-ux500.

Cc: Stefan Nilsson <stefan.xk.nilsson@stericsson.com>
Cc: Martin Persson <martin.persson@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
2010-12-22 09:26:49 +01:00
Kim Lilliestierna XX
e83293233f CAIF: Fix U5500 compile error for shared memory driver
Rearrange pr_fmt so it compiles.

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 08:35:29 -08:00
Vasiliy Kulikov
8ea91226ec net: caif: spi: fix potential NULL dereference
alloc_netdev() is not checked here for NULL return value.  dev is
check instead.  It might lead to NULL dereference of ndev.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-18 10:35:58 -08:00
Sjur Brændeland
2c24a5d1b4 caif: SPI-driver bugfix - incorrect padding.
Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-03 18:50:03 -07:00
Amarnath Revanna
1933f0c094 caif-u5500: Build config for CAIF shared mem driver
Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-27 12:29:53 -07:00
Amarnath Revanna
e57731f4dd caif-u5500: CAIF shared memory mailbox interface
Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-27 12:29:52 -07:00
sjur.brandeland@stericsson.com
dfae55d6a5 caif-u5500: CAIF shared memory transport protocol
Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-27 12:29:52 -07:00
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