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439885 commits

Author SHA1 Message Date
Roi Dayan
1d6c2b736f IB/iser: Drain the tx cq once before looping on the rx cq
The iser disconnection flow isn't done before all the inflight
recv/send buffers posted to the QP are either flushed or normally
completed to the CQ that serves this connection.  The condition check
is done in iser_handle_comp_error().

Currently, it's possible for the send buffer completion that makes the
posted send buffers counter reach zero to be polled in the drain tx
call, which is after the rx cq is fully drained.  Since this
completion might be not an error one (for example, it might be a
completion of the logout request iSCSI PDU) we will skip
iser_handle_comp_error().  So the connection will never terminate from
the iscsi stack point of view, and we hang.

To resolve this race, do the draining of the tx cq before the loop on
the rx cq.

Signed-off-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-04-01 11:09:46 -07:00
Randy Dunlap
39c978cd17 IB/iser: Fix sector_t format warning
Fix pr_err (printk) format warning:

    drivers/infiniband/ulp/iser/iser_verbs.c:1181:4: warning: format '%lx' expects argument of type 'long unsigned int', but argument 3 has type 'sector_t' [-Wformat]

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-04-01 11:01:08 -07:00
Linus Torvalds
1ead658124 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer changes from Thomas Gleixner:
 "This assorted collection provides:

   - A new timer based timer broadcast feature for systems which do not
     provide a global accessible timer device.  That allows those
     systems to put CPUs into deep idle states where the per cpu timer
     device stops.

   - A few NOHZ_FULL related improvements to the timer wheel

   - The usual updates to timer devices found in ARM SoCs

   - Small improvements and updates all over the place"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  tick: Remove code duplication in tick_handle_periodic()
  tick: Fix spelling mistake in tick_handle_periodic()
  x86: hpet: Use proper destructor for delayed work
  workqueue: Provide destroy_delayed_work_on_stack()
  clocksource: CMT, MTU2, TMU and STI should depend on GENERIC_CLOCKEVENTS
  timer: Remove code redundancy while calling get_nohz_timer_target()
  hrtimer: Rearrange comments in the order struct members are declared
  timer: Use variable head instead of &work_list in __run_timers()
  clocksource: exynos_mct: silence a static checker warning
  arm: zynq: Add support for cpufreq
  arm: zynq: Don't use arm_global_timer with cpufreq
  clocksource/cadence_ttc: Overhaul clocksource frequency adjustment
  clocksource/cadence_ttc: Call clockevents_update_freq() with IRQs enabled
  clocksource: Add Kconfig entries for CMT, MTU2, TMU and STI
  sh: Remove Kconfig entries for TMU, CMT and MTU2
  ARM: shmobile: Remove CMT, TMU and STI Kconfig entries
  clocksource: armada-370-xp: Use atomic access for shared registers
  clocksource: orion: Use atomic access for shared registers
  clocksource: timer-keystone: Delete unnecessary variable
  clocksource: timer-keystone: introduce clocksource driver for Keystone
  ...
2014-04-01 11:00:07 -07:00
Linus Torvalds
b6d739e958 Merge branch 'x86-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 iommu quirk fix from Thomas Gleixner:
 "A quirk for the iommu quirk to include silicon which was assumed not
  to be out in the wild.

  This time with the correct logic applied"

* 'x86-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Adjust irq remapping quirk for older revisions of 5500/5520 chipsets
2014-04-01 10:59:08 -07:00
Dan Carpenter
4661bd798f mlx4_core: Make buffer larger to avoid overflow warning
My static checker complains that the sprintf() here can overflow.

	drivers/infiniband/hw/mlx4/main.c:1836 mlx4_ib_alloc_eqs()
	error: format string overflow. buf_size: 32 length: 69

This seems like a valid complaint.  The "dev->pdev->bus->name" string
can be 48 characters long.  I just made the buffer 80 characters instead
of 69 and I changed the sprintf() to snprintf().

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-04-01 10:53:29 -07:00
Dan Carpenter
3839d8ac1b mlx4_core: Fix some indenting in mlx4_ib_add()
The code was indented too far and also kernel style says we should have
curly braces.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-04-01 10:52:18 -07:00
Yan Burman
2c34e68f42 IB/mad: Check and handle potential DMA mapping errors
Running with DMA_API_DEBUG enabled and not checking for DMA mapping
errors triggers a kernel stack trace with "DMA-API: device driver
failed to check map error" message.  Add these checks to the MAD
module, both to be be more robust and also eliminate these
false-positive stack traces.

Signed-off-by: Yan Burman <yanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-04-01 10:36:07 -07:00
Yann Droneaud
5bdb0f02ad IB/ehca: Returns an error on ib_copy_to_udata() failure
In case of error when writing to userspace, function ehca_create_cq()
does not set an error code before following its error path.

This patch sets the error code to -EFAULT when ib_copy_to_udata()
fails.

This was caught when using spatch (aka. coccinelle)
to rewrite call to ib_copy_{from,to}_udata().

Link: 75ebf2c103:ib_copy_udata.cocci
Link: http://marc.info/?i=cover.1394485254.git.ydroneaud@opteya.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-04-01 10:36:07 -07:00
Yann Droneaud
08e74c4b00 IB/mthca: Return an error on ib_copy_to_udata() failure
In case of error when writing to userspace, the function mthca_create_cq()
does not set an error code before following its error path.

This patch sets the error code to -EFAULT when ib_copy_to_udata() fails.

This was caught when using spatch (aka. coccinelle)
to rewrite call to ib_copy_{from,to}_udata().

Link: 75ebf2c103:ib_copy_udata.cocci
Link: http://marc.info/?i=cover.1394485254.git.ydroneaud@opteya.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-04-01 10:35:42 -07:00
Linus Torvalds
99f7b025bf Merge branch 'x86-threadinfo-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 threadinfo changes from Ingo Molnar:
 "The main change here is the consolidation/unification of 32 and 64 bit
  thread_info handling methods, from Steve Rostedt"

* 'x86-threadinfo-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, threadinfo: Redo "x86: Use inline assembler to get sp"
  x86: Clean up dumpstack_64.c code
  x86: Keep thread_info on thread stack in x86_32
  x86: Prepare removal of previous_esp from i386 thread_info structure
  x86: Nuke GET_THREAD_INFO_WITH_ESP() macro for i386
  x86: Nuke the supervisor_stack field in i386 thread_info
2014-04-01 10:17:18 -07:00
Linus Torvalds
a21e40877a Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Ingo Molnar:
 "The main purpose is to fix a full dynticks bug related to
  virtualization, where steal time accounting appears to be zero in
  /proc/stat even after a few seconds of competing guests running busy
  loops in a same host CPU.  It's not a regression though as it was
  there since the beginning.

  The other commits are preparatory work to fix the bug and various
  cleanups"

* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arch: Remove stub cputime.h headers
  sched: Remove needless round trip nsecs <-> tick conversion of steal time
  cputime: Fix jiffies based cputime assumption on steal accounting
  cputime: Bring cputime -> nsecs conversion
  cputime: Default implementation of nsecs -> cputime conversion
  cputime: Fix nsecs_to_cputime() return type cast
2014-04-01 10:16:10 -07:00
Linus Torvalds
b9b16a7922 Merge branch 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpufeature update from Ingo Molnar:
 "Two refinements to clflushopt support"

* 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, cpufeature: If we disable CLFLUSH, we should disable CLFLUSHOPT
  x86, cpufeature: Rename X86_FEATURE_CLFLSH to X86_FEATURE_CLFLUSH
2014-04-01 10:11:21 -07:00
Jiri Kosina
3ae821effd HID: sony: fix force feedback mismerge
Fix unfortunate mismerge between the fixes and sony branch causing
code duplication and unterminated basic block.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-04-01 19:11:09 +02:00
Linus Torvalds
4b2ce8f15f Merge branch 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 reboot changes from Ingo Molnar:
 "Refine the reboot logic around the CF9 and EFI reboot methods, to make
  it more robust.  The expectation is for no working system to break,
  and for a couple of reboot-force systems to start rebooting
  automatically again"

* 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, reboot: Only use CF9_COND automatically, not CF9
  x86, reboot: Add EFI and CF9 reboot methods into the default list
2014-04-01 10:10:59 -07:00
Jiri Kosina
fa1054a29b Merge branches 'for-3.15/multitouch', 'for-3.15/sony' and 'for-3.15/uhid' into for-linus 2014-04-01 19:06:50 +02:00
Jiri Kosina
6cf8c85f8b Merge branch 'for-3.15/microsoft' into for-linus
Conflicts:
	drivers/hid/hid-core.c
2014-04-01 19:06:41 +02:00
Jiri Kosina
ded75664d1 Merge branch 'for-3.15/hid-sensor-hub' into for-linus 2014-04-01 19:05:30 +02:00
Jiri Kosina
ad295b6d57 Merge branch 'for-3.15/hid-core-ll-transport-cleanup' into for-linus
Conflicts:
	drivers/hid/hid-ids.h
	drivers/hid/hid-sony.c
	drivers/hid/i2c-hid/i2c-hid.c
2014-04-01 19:05:09 +02:00
Jiri Kosina
ba04a57b4a Merge branch 'for-3.15/i2c-hid' into for-linus 2014-04-01 18:56:31 +02:00
Jiri Kosina
ee5f68e6c2 Merge branch 'for-3.15/ll-driver-new-callbacks' into for-linus 2014-04-01 18:56:24 +02:00
Linus Torvalds
1694f0bb8f Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm change from Ingo Molnar:
 "A micro-optimization for acpi_numa_slit_init()"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Avoid duplicated pxm_to_node() calls
2014-04-01 09:50:01 -07:00
Linus Torvalds
f27a15d246 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/linux-avr32
Pull AVR32 updates from Hans-Christian Egtvedt.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/linux-avr32:
  avr32: replace simple_strtoul() with kstrtoul()
  arch/avr32/mm/cache.c: export symbol flush_icache_range() for module using
  avr32: remove cpu_data macro to fix compiles
2014-04-01 09:49:16 -07:00
Jiri Kosina
b95dd3ca03 Merge branch 'for-3.15/hid-core-ll-transport-cleanup' into for-3.15/sony 2014-04-01 18:45:27 +02:00
Frank Praznik
2078b9bb24 HID: sony: Set the quriks flag for Bluetooth controllers
The Sixaxis and DualShock 4 want HID output reports sent on the control
endpoint when connected via Bluetooth.  Set the
HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP flag for these devices so hidraw write()
works properly.

Signed-off-by: Frank Praznik <frank.praznik@oh.rr.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-04-01 18:44:06 +02:00
Frank Praznik
914c578391 HID: sony: Fix Sixaxis cable state detection
Byte 31 of the Sixaxis report can change depending on whether or not the
controller is rumbling.  Using bit 3 is the only reliable way to detect the
state of the cable regardless of rumble activity.

Signed-off-by: Frank Praznik <frank.praznik@oh.rr.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-04-01 18:44:06 +02:00
Petri Gynther
4522643aa9 HID: uhid: Add UHID_CREATE2 + UHID_INPUT2
UHID_CREATE2:
HID report descriptor data (rd_data) is an array in struct uhid_create2_req,
instead of a pointer. Enables use from languages that don't support pointers,
e.g. Python.

UHID_INPUT2:
Data array is the last field of struct uhid_input2_req. Enables userspace to
write only the required bytes to kernel (ev.type + ev.u.input2.size + the part
of the data array that matters), instead of the entire struct uhid_input2_req.

Note:
UHID_CREATE2 increases the total size of struct uhid_event slightly, thus
increasing the size of messages that are queued for userspace. However, this
won't affect the userspace processing of these events.

[Jiri Kosina <jkosina@suse.cz>: adjust to hid_get_raw_report() and
				hid_output_raw_report() API changes]

Signed-off-by: Petri Gynther <pgynther@google.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-04-01 18:27:33 +02:00
Miklos Szeredi
bd42998a6b ext4: add cross rename support
Implement RENAME_EXCHANGE flag in renameat2 syscall.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
2014-04-01 17:08:44 +02:00
Miklos Szeredi
bd1af145b9 ext4: rename: split out helper functions
Cross rename (exchange source and dest) will need to call some of these
helpers for both source and dest, while overwriting rename currently only
calls them for one or the other.  This also makes the code easier to
follow.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
2014-04-01 17:08:44 +02:00
Miklos Szeredi
0d7d5d678b ext4: rename: move EMLINK check up
Move checking i_nlink from after ext4_get_first_dir_block() to before.  The
check doesn't rely on the result of that function and the function only
fails on fs corruption, so the order shouldn't matter.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
2014-04-01 17:08:44 +02:00
Miklos Szeredi
c0d268c366 ext4: rename: create ext4_renament structure for local vars
Need to split up ext4_rename() into helpers but there are too many local
variables involved, so create a new structure.  This also, apparently,
makes the generated code size slightly smaller.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
2014-04-01 17:08:43 +02:00
Miklos Szeredi
da1ce0670c vfs: add cross-rename
If flags contain RENAME_EXCHANGE then exchange source and destination files.
There's no restriction on the type of the files; e.g. a directory can be
exchanged with a symlink.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
2014-04-01 17:08:43 +02:00
J. Bruce Fields
4fd699ae3f vfs: lock_two_nondirectories: allow directory args
lock_two_nondirectories warned if either of its args was a directory.
Instead just ignore the directory args.  This is needed for locking in
cross rename.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-01 17:08:43 +02:00
Miklos Szeredi
0b3974eb04 security: add flags to rename hooks
Add flags to security_path_rename() and security_inode_rename() hooks.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
2014-04-01 17:08:43 +02:00
Miklos Szeredi
0a7c3937a1 vfs: add RENAME_NOREPLACE flag
If this flag is specified and the target of the rename exists then the
rename syscall fails with EEXIST.

The VFS does the existence checking, so it is trivial to enable for most
local filesystems.  This patch only enables it in ext4.

For network filesystems the VFS check is not enough as there may be a race
between a remote create and the rename, so these filesystems need to handle
this flag in their ->rename() implementations to ensure atomicity.

Andy writes about why this is useful:

"The trivial answer: to eliminate the race condition from 'mv -i'.

Another answer: there's a common pattern to atomically create a file
with contents: open a temporary file, write to it, optionally fsync
it, close it, then link(2) it to the final name, then unlink the
temporary file.

The reason to use link(2) is because it won't silently clobber the destination.

This is annoying:
 - It requires an extra system call that shouldn't be necessary.
 - It doesn't work on (IMO sensible) filesystems that don't support
hard links (e.g. vfat).
 - It's not atomic -- there's an intermediate state where both files exist.
 - It's ugly.

The new rename flag will make this totally sensible.

To be fair, on new enough kernels, you can also use O_TMPFILE and
linkat to achieve the same thing even more cleanly."

Suggested-by: Andy Lutomirski <luto@amacapital.net> 
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
2014-04-01 17:08:43 +02:00
Miklos Szeredi
520c8b1650 vfs: add renameat2 syscall
Add new renameat2 syscall, which is the same as renameat with an added
flags argument.

Pass flags to vfs_rename() and to i_op->rename() as well.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
2014-04-01 17:08:42 +02:00
Miklos Szeredi
bc27027a73 vfs: rename: use common code for dir and non-dir
There's actually very little difference between vfs_rename_dir() and
vfs_rename_other() so move both inline into vfs_rename() which still stays
reasonably readable.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
2014-04-01 17:08:42 +02:00
Miklos Szeredi
de22a4c372 vfs: rename: move d_move() up
Move the d_move() in vfs_rename_dir() up, similarly to how it's done in
vfs_rename_other().  The next patch will consolidate these two functions
and this is the only structural difference between them.

I'm not sure if doing the d_move() after the dput is even valid.  But there
may be a logical explanation for that.  But moving the d_move() before the
dput() (and the mutex_unlock()) should definitely not hurt.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
2014-04-01 17:08:42 +02:00
Miklos Szeredi
44b1d53043 vfs: add d_is_dir()
Add d_is_dir(dentry) helper which is analogous to S_ISDIR().

To avoid confusion, rename d_is_directory() to d_can_lookup().

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
2014-04-01 17:08:41 +02:00
David Woodhouse
7713ec066a iommu/vt-d: Fix error handling in ANDD processing
If we failed to find an ACPI device to correspond to an ANDD record, we
would fail to increment our pointer and would just process the same record
over and over again, with predictable results.

Turn it from a while() loop into a for() loop to let the 'continue' in
the error paths work correctly.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2014-04-01 14:58:38 +01:00
Thierry Reding
2ae69a4604 pwm: pxa: Constify OF match table
The table is never modified and all OF functions that use it take a
const struct of_device_id *.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-04-01 14:06:43 +02:00
Thierry Reding
fdec4f7271 pwm: pxa: Fix typo "pwm" -> "PWM"
Being an abbreviation, PWM should always be capitalized in prose.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-04-01 14:04:59 +02:00
Thierry Reding
f409cd3833 Revert "pwm: pxa: Use of_match_ptr()"
This reverts commit 8468949cdd.

The OF match table dummy for non-OF configurations cannot be removed
because it is still used by the pxa_pwm_get_id_dt() function.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-04-01 14:01:32 +02:00
Gerald Schaefer
9f0128f9e7 s390/sclp: add timeout for queued requests
This patch adds a timeout option for queued requests and introduces
sclp_sync_request_timeout() to use this timer. With this, blocking the
system too long, e.g. during an SE reboot, can be avoided in critical
situations like CPU and memory hotplug.
Since there is no way to cancel a running request, this timeout only
applies to queued requests that have not yet been started.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-04-01 13:25:26 +02:00
Mika Westerberg
d16a5aa9e8 pwm: add support for Intel Low Power Subsystem PWM
Add support for Intel Low Power I/O subsystem PWM controllers found on
Intel BayTrail SoC.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Chew, Kean Ho <kean.ho.chew@intel.com>
Signed-off-by: Chang, Rebecca Swee Fun <rebecca.swee.fun.chang@intel.com>
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-04-01 12:03:40 +02:00
Thomas Gleixner
b1d8e431bd can: c_can: Avoid led toggling for every packet.
There is no point to toggle the RX led for every packet. Especially if
we have a full FIFO we want to avoid everything we can.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:02 +02:00
Thomas Gleixner
5a7513adab can: c_can: Simplify TX interrupt cleanup
The function loads the message object from the hardware to get the
payload length. The previous patch stores that information in an
array, so we can avoid the hardware access.

Remove the hardware access and move the led toggle outside of the
spinlocked region. Toggle the led only once when at least one packet
has been received.

Binary size shrinks along with the code

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:01 +02:00
Thomas Gleixner
9024700854 can: c_can: Store dlc private
We can avoid the HW access in TX cleanup path for retrieving the DLC
of the sent package if we store the DLC in a private array.

Ideally this should be handled in the can_echo_skb functions, but I
leave that exercise to the CAN folks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:01 +02:00
Thomas Gleixner
c0a9f4d396 can: c_can: Reduce register access
commit 4ce78a838c (can: c_can: Speed up rx_poll function) hyped a
performance improvement by reducing the access to the interrupt
pending register from a dual 16 bit to a single 16 bit access. Wow!

Thereby it crippled the driver to cast the 16 msg objects in stone,
which is completly braindead as contemporary hardware has up to 128
message objects. Supporting larger object buffers is a major surgery,
but it'd be definitely worth it especially as the driver does not
support HW message filtering ....

The logic of the "FIFO" implementation is to split the FIFO in half.

For the lower half we read the buffers and clear the interrupt pending
bit, but keep the newdat bit set, so the HW will queue above those
buffers.

When we read out the last low buffer then we reenable all the low half
buffers by clearing the newdat bit.

The upper half buffers clear the newdat and the interrupt pending bit
right away as we know that the lower half bits are clear and give us a
headstart against the hardware.

Now the implementation is:

    transfer_message_object()
    read_object_and_put_into_skb();

    if (obj < END_OF_LOW_BUF)
       clear_intpending(obj)
    else if (obj > END_OF_LOW_BUF)
       clear_intpending_and_newdat(obj)
    else if (obj == END_OF_LOW_BUF)
       clear_newdat_of_all_low_objects()

The hardware allows to avoid most of the mess simply because we can
tell the transfer_message_object() function to clear bits right away.

So we can be clever and do:

   if (obj <= END_OF_LOW_BUF)
      ctrl = TRANSFER_MSG | CLEAR_INTPND;
   else
      ctrl = TRANSFER_MSG | CLEAR_INTPND | CLEAR_NEWDAT;

    transfer_message_object(ctrl)
    read_object_and_put_into_skb();

    if (obj == END_OF_LOW_BUF)
       clear_newdat_of_all_low_objects()

So we save a complete control operation on all message objects except
the one which is the end of the low buffer. That's a few micro seconds
per object.

I'm not adding a boasting profile to that, simply because it's self
explaining.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[mkl: adjusted subject and commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:01 +02:00
Thomas Gleixner
520f570c43 can: c_can: Make the code readable
If every other line contains line breaks, that's a clear sign for
indentation level madness. Split out the inner loop and move the code
to a separate function. gcc creates slightly worse code for that, but
we'll fix that in the next step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[mkl: adjusted subject]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:00 +02:00
Thomas Gleixner
bf88a20611 can: c_can: Provide protection in the xmit path
The network core does not serialize the access to the hardware. The
xmit related code lets the following happen:

CPU0 	     	       CPU1
interrupt()
 do_poll()
   c_can_do_tx()
    Fiddle with HW and	xmit()
    internal data	  Fiddle with HW and
    	     		  internal data

due the complete lack of serialization.

Add proper locking.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:00 +02:00