firewire: core: add memo about the caller of show functions for device attributes

In the case of firewire core function, the caller of show functions for
device attributes is not only sysfs user, but also device initialization.

This commit adds memo about it against the typical assumption that the
functions are just dedicated to sysfs user.

Link: https://lore.kernel.org/lkml/20240318091759.678326-1-o-takashi@sakamocchi.jp/
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

Revert "firewire: Kill unnecessary buf check in device_attribute.show"

This reverts commit 4a2b06ca33763b363038d333274e212db6ff0de1.

The previous fix didn't consider callers from other than sysfs. Revert
it to fix the NULL dereference

kernel: ? sysfs_emit+0xb5/0xc0
kernel: show_immediate+0x13f/0x1d0 [firewire_core]
kernel: init_fw_attribute_group+0x81/0x150 [firewire_core]
kernel: create_units+0x119/0x160 [firewire_core]
kernel: fw_device_init+0x1a9/0x330 [firewire_core]
kernel: fw_device_workfn+0x12/0x20 [firewire_core]
kernel: process_one_work+0x16f/0x350
kernel: worker_thread+0x306/0x440
kernel: ? __pfx_worker_thread+0x10/0x10
kernel: kthread+0xf2/0x120
kernel: ? __pfx_kthread+0x10/0x10
kernel: ret_from_fork+0x47/0x70
kernel: ? __pfx_kthread+0x10/0x10
kernel: ret_from_fork_asm+0x1b/0x30
kernel: </TASK>
kernel: ---[ end trace 0000000000000000 ]---
kernel: ------------[ cut here ]------------

Fixes: 4a2b06ca3376 ("firewire: Kill unnecessary buf check in device_attribute.show")
Reported-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Link: https://lore.kernel.org/lkml/625470f3-b196-43f7-9844-fa1cb6da99f8@fujitsu.com/
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: fix build failure due to the caller of fw_csr_string()

A commit 47dc55181dcb ("firewire: core: search descriptor leaf just after
vendor directory entry in root directory") for v6.8-rc3 and a commit
67a5a58c0443 ("firewire: Kill unnecessary buf check in
device_attribute.show") for v6.9 bring build failure in for-next tree due
to the change of the name of local variable.

This commit fixes it.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/lkml/20240202111602.6f6e2c1a@canb.auug.org.au/
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202402022343.NkgsMITA-lkp@intel.com/
Link: https://lore.kernel.org/r/20240205060448.13881-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: Convert snprintf/sprintf to sysfs_emit

Per filesystems/sysfs.rst, show() should only use sysfs_emit()
or sysfs_emit_at() when formatting the value to be returned to user space.

coccinelle complains that there are still a couple of functions that use
snprintf(). Convert them to sysfs_emit().

> drivers/firewire/core-device.c:326:8-16: WARNING: please use sysfs_emit or sysfs_emit_at

No functional change intended

Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Link: https://lore.kernel.org/r/20240122053942.80648-2-lizhijian@fujitsu.com
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: Kill unnecessary buf check in device_attribute.show

Per Documentation/filesystems/sysfs.rst:
> sysfs allocates a buffer of size (PAGE_SIZE) and passes it to the
> method.

So we can kill the unnecessary buf check safely.

Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Link: https://lore.kernel.org/r/20240122053942.80648-1-lizhijian@fujitsu.com
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: search descriptor leaf just after vendor directory entry in root directory

It appears that Sony DVMC-DA1 has a quirk that the descriptor leaf entry
locates just after the vendor directory entry in root directory. This is
not conformant to the legacy layout of configuration ROM described in
Configuration ROM for AV/C Devices 1.0 (1394 Trading Association, Dec 2000,
TA Document 1999027).

This commit changes current implementation to parse configuration ROM for
device attributes so that the descriptor leaf entry can be detected for
the vendor name.

$ config-rom-pretty-printer < Sony-DVMC-DA1.img
ROM header and bus information block
-----------------------------------------------------------------
1024 041ee7fb bus_info_length 4, crc_length 30, crc 59387
1028 31333934 bus_name "1394"
1032 e0644000 irmc 1, cmc 1, isc 1, bmc 0, cyc_clk_acc 100, max_rec 4 (32)
1036 08004603 company_id 080046 |
1040 0014193c device_id 12886219068 | EUI-64 576537731003586876

root directory
-----------------------------------------------------------------
1044 0006b681 directory_length 6, crc 46721
1048 03080046 vendor
1052 0c0083c0 node capabilities: per IEEE 1394
1056 8d00000a --> eui-64 leaf at 1096
1060 d1000003 --> unit directory at 1072
1064 c3000005 --> vendor directory at 1084
1068 8100000a --> descriptor leaf at 1108

unit directory at 1072
-----------------------------------------------------------------
1072 0002cdbf directory_length 2, crc 52671
1076 1200a02d specifier id
1080 13010000 version

vendor directory at 1084
-----------------------------------------------------------------
1084 00020cfe directory_length 2, crc 3326
1088 17fa0000 model
1092 81000008 --> descriptor leaf at 1124

eui-64 leaf at 1096
-----------------------------------------------------------------
1096 0002c66e leaf_length 2, crc 50798
1100 08004603 company_id 080046 |
1104 0014193c device_id 12886219068 | EUI-64 576537731003586876

descriptor leaf at 1108
-----------------------------------------------------------------
1108 00039e26 leaf_length 3, crc 40486
1112 00000000 textual descriptor
1116 00000000 minimal ASCII
1120 536f6e79 "Sony"

descriptor leaf at 1124
-----------------------------------------------------------------
1124 0005001d leaf_length 5, crc 29
1128 00000000 textual descriptor
1132 00000000 minimal ASCII
1136 44564d43 "DVMC"
1140 2d444131 "-DA1"
1144 00000000

Suggested-by: Adam Goldman <adamg@pobox.com>
Tested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20240130100409.30128-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: correct documentation of fw_csr_string() kernel API

Against its current description, the kernel API can accepts all types of
directory entries.

This commit corrects the documentation.

Cc: stable@vger.kernel.org
Fixes: 3c2c58cb33b3 ("firewire: core: fw_csr_string addendum")
Link: https://lore.kernel.org/r/20240130100409.30128-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: fill model field in modalias of unit device for legacy layout of configuration ROM

As the last part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when
constructing modalias for unit device. The change brings loss of backward
compatibility since it can fill model field ('mo') which is 0 at current
implementation in the case. However, we can be optimistic against
regression for unit drivers in kernel, due to some points:

1. ALSA drivers for audio and music units use the model fields to match
device, however all of supported devices does not have such legacy
layout.
2. the other unit drivers (e.g. sbp2) does not use the model field to
match device.

The rest of concern is user space application. The most of applications
just take care of node device and does not use the modalias of unit
device, thus the change does not affect to them. But systemd project is
known to get affects from the change since it includes hwdb to take udev
to configure fw character device conveniently. I have a plan to work for
systemd so that the access permission of character device could be kept
across the change.

Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-9-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: detect model name for legacy layout of configuration ROM

As the part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when showing
device attribute for node device. This change expects 'model_name'
attribute appears in node device, however it is probable to see the other
types of descriptor leaf if the vendor directory includes.

Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-8-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: detect numeric model identifier for legacy layout of configuration ROM

As the part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when showing
device attribute for node device. This change expects 'model' attribute
appears in node device, however it is probable to see the other types of
immediate values if the vendor directory includes.

Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-7-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: test: add KUnit test for device attributes

The traverse over CSR space results in attributes of node and unit
devices. Any test of the traverse is useful.

This commit adds a skeleton of KUnit test for the purpose.

Link: https://lore.kernel.org/r/20231221134849.603857-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: replace magic number with macro

In IEEE 1394 specification, the size of bus information block of
configuration ROM is fixed to 5, thus the offset of root directory is 5.
Current implementation to handle device structures has the hard-coded
offset.

This commit replaces the offset with macro.

Link: https://lore.kernel.org/r/20231221134849.603857-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: adds constant qualifier for local helper functions

Some local functions just handles given argument as mutable, thus it is
preferable to add constant qualifier to them.

Link: https://lore.kernel.org/r/20231221134849.603857-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: make fw_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the fw_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: linux1394-devel@lists.sourceforge.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/2023121931-skydiver-dodgy-d1bd@gregkh
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: fix possible memory leak in create_units()

If device_register() fails, the refcount of device is not 0, the name
allocated in dev_set_name() is leaked. To fix this by calling put_device(),
so that it will be freed in callback function kobject_cleanup().

unreferenced object 0xffff9d99035c7a90 (size 8):
comm "systemd-udevd", pid 168, jiffies 4294672386 (age 152.089s)
hex dump (first 8 bytes):
66 77 30 2e 30 00 ff ff fw0.0...
backtrace:
[<00000000e1d62bac>] __kmem_cache_alloc_node+0x1e9/0x360
[<00000000bbeaff31>] __kmalloc_node_track_caller+0x44/0x1a0
[<00000000491f2fb4>] kvasprintf+0x67/0xd0
[<000000005b960ddc>] kobject_set_name_vargs+0x1e/0x90
[<00000000427ac591>] dev_set_name+0x4e/0x70
[<000000003b4e447d>] create_units+0xc5/0x110

fw_unit_release() will be called in the error path, move fw_device_get()
before calling device_register() to keep balanced with fw_device_put() in
fw_unit_release().

Cc: stable@vger.kernel.org
Fixes: 1fa5ae857bb1 ("driver core: get rid of struct device's bus_id string array")
Fixes: a1f64819fe9f ("firewire: struct device - replace bus_id with dev_name(), dev_set_name()")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

Revert "firewire: core: obsolete usage of GFP_ATOMIC at building node tree"

This reverts commit 06f45435d985d60d7d2fe2424fbb9909d177a63d.

John Ogness reports the case that the allocation is in atomic context under
acquired spin-lock.

[ 12.555784] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
[ 12.555808] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 70, name: kworker/1:2
[ 12.555814] preempt_count: 1, expected: 0
[ 12.555820] INFO: lockdep is turned off.
[ 12.555824] irq event stamp: 208
[ 12.555828] hardirqs last enabled at (207): [<c00000000111e414>] ._raw_spin_unlock_irq+0x44/0x80
[ 12.555850] hardirqs last disabled at (208): [<c00000000110ff94>] .__schedule+0x854/0xfe0
[ 12.555859] softirqs last enabled at (188): [<c000000000f73504>] .addrconf_verify_rtnl+0x2c4/0xb70
[ 12.555872] softirqs last disabled at (182): [<c000000000f732b0>] .addrconf_verify_rtnl+0x70/0xb70
[ 12.555884] CPU: 1 PID: 70 Comm: kworker/1:2 Tainted: G S 6.6.0-rc1 #1
[ 12.555893] Hardware name: PowerMac7,2 PPC970 0x390202 PowerMac
[ 12.555898] Workqueue: firewire_ohci .bus_reset_work [firewire_ohci]
[ 12.555939] Call Trace:
[ 12.555944] [c000000009677830] [c0000000010d83c0] .dump_stack_lvl+0x8c/0xd0 (unreliable)
[ 12.555963] [c0000000096778b0] [c000000000140270] .__might_resched+0x320/0x340
[ 12.555978] [c000000009677940] [c000000000497600] .__kmem_cache_alloc_node+0x390/0x460
[ 12.555993] [c000000009677a10] [c0000000003fe620] .__kmalloc+0x70/0x310
[ 12.556007] [c000000009677ac0] [c0003d00004e2268] .fw_core_handle_bus_reset+0x2c8/0xba0 [firewire_core]
[ 12.556060] [c000000009677c20] [c0003d0000491190] .bus_reset_work+0x330/0x9b0 [firewire_ohci]
[ 12.556079] [c000000009677d10] [c00000000011d0d0] .process_one_work+0x280/0x6f0
[ 12.556094] [c000000009677e10] [c00000000011d8a0] .worker_thread+0x360/0x500
[ 12.556107] [c000000009677ef0] [c00000000012e3b4] .kthread+0x154/0x160
[ 12.556120] [c000000009677f90] [c00000000000bfa8] .start_kernel_thread+0x10/0x14

Cc: stable@kernel.org
Reported-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/lkml/87jzsuv1xk.fsf@jogness.linutronix.de/raw
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: obsolete usage of GFP_ATOMIC at building node tree

The flag of GFP_ATOMIC is given to the call of kmalloc when building node
tree, but the call is not atomic context. The call of
fw_core_handle_bus_reset() and fw_core_remove_card() builds the tree,
while they are done in specific workqueue or pci remove callback.

This commit obsolete the usage of GFP_ATOMIC.

Link: https://lore.kernel.org/r/20230604070255.172700-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

driver core: make struct device_type.uevent() take a const *

The uevent() callback in struct device_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bard Liao <yung-chuan.liao@linux.intel.com>
Cc: Chaitanya Kulkarni <kch@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jilin Yuan <yuanjilin@cdjrlc.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Mark Gross <markgross@kernel.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Maximilian Luz <luzmaximilian@gmail.com>
Cc: Michael Jamet <michael.jamet@intel.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Sanyog Kale <sanyog.r.kale@intel.com>
Cc: Sean Young <sean@mess.org>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Won Chung <wonchung@google.com>
Cc: Yehezkel Bernat <YehezkelShB@gmail.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for Thunderbolt
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Wolfram Sang <wsa@kernel.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-6-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

firewire: convert sysfs sprintf/snprintf family to sysfs_emit

Fix the following coccicheck warning:

./drivers/firewire/core-device.c:375:8-16: WARNING: use scnprintf or
sprintf.

Reported-by: Abaci Robot<abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20220615121505.61412-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

bus: Make remove callback return void

The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.

With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.

Reviewed-by: Tom Rix <trix@redhat.com> (For fpga)
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts)
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb)
Acked-by: Pali Rohár <pali@kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media)
Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform)
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com> (For xen)
Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd)
Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb)
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus)
Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio)
Acked-by: Maximilian Luz <luzmaximilian@gmail.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack)
Acked-by: Geoff Levand <geoff@infradead.org> (For ps3)
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt)
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th)
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia)
Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI)
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid)
Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa)
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire)
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid)
Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox)
Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss)
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC)
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

firewire: replace tricky statement by two simple ones

struct fw_driver::remove returns void, still the comma expression's value
is zero. This is harder to parse than necessary, so replace the single
expression by two easier ones.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20210126221444.713837-1-uwe@kleine-koenig.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

firewire: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warnings:

drivers/firewire/core-device.c: In function ‘set_broadcast_channel’:
drivers/firewire/core-device.c:969:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (data & cpu_to_be32(1 << 31)) {
^
drivers/firewire/core-device.c:974:3: note: here
case RCODE_ADDRESS_ERROR:
^~~~
drivers/firewire/core-iso.c: In function ‘manage_channel’:
drivers/firewire/core-iso.c:308:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if ((data[0] & bit) == (data[1] & bit))
^
drivers/firewire/core-iso.c:312:3: note: here
default:
^~~~~~~
drivers/firewire/core-topology.c: In function ‘count_ports’:
drivers/firewire/core-topology.c:69:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
(*child_port_count)++;
~~~~~~~~~~~~~~~~~~~^~
drivers/firewire/core-topology.c:70:3: note: here
case SELFID_PORT_PARENT:
^~~~

Warning level 3 was used: -Wimplicit-fallthrough=3

Notice that in some cases, the code comment is modified in
accordance with what GCC is expecting to find.

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Cc: Kees Cook <keescook@chromium.org>
Cc: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (reworded a comment)
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scripts/spelling.txt: add "intialization" pattern and fix typo instances

Fix typos and add the following to the scripts/spelling.txt:

intialization||initialization

The "inintialization" in drivers/acpi/spcr.c is a different pattern but
I fixed it as well in this commit.

Link: http://lkml.kernel.org/r/1481573103-11329-16-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

firewire: core: document fw_csr_string's truncation of long strings

fw_csr_string() truncates and terminates target strings like strlcpy()
does. Unlike strlcpy(), it returns the target strlen, not the source
strlen, hence users of fw_csr_string() are unable to detect truncation.

Point this behavior out in the kerneldoc comment.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: don't use PREPARE_DELAYED_WORK

PREPARE_[DELAYED_]WORK() are being phased out. They have few users
and a nasty surprise in terms of reentrancy guarantee as workqueue
considers work items to be different if they don't have the same work
function.

firewire core-device and sbp2 have been been multiplexing work items
with multiple work functions. Introduce fw_device_workfn() and
sbp2_lu_workfn() which invoke fw_device->workfn and
sbp2_logical_unit->workfn respectively and always use the two
functions as the work functions and update the users to set the
->workfn fields instead of overriding work functions using
PREPARE_DELAYED_WORK().

This fixes a variety of possible regressions since a2c1c57be8d9
"workqueue: consider work function when searching for busy work items"
due to which fw_workqueue lost its required non-reentrancy property.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: linux1394-devel@lists.sourceforge.net
Cc: stable@vger.kernel.org # v3.9+
Cc: stable@vger.kernel.org # v3.8.2+
Cc: stable@vger.kernel.org # v3.4.60+
Cc: stable@vger.kernel.org # v3.2.40+

firewire: remove support of fw_driver.driver.probe and .remove methods

After all IEEE 1394 high-level drivers being converted to bus-specific
.probe/.remove methods, remove support of the obsolete generic methods.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: introduce fw_driver.probe and .remove methods

FireWire upper layer drivers are converted from generic
struct driver.probe() and .remove()
to bus-specific
struct fw_driver.probe() and .remove().

The new .probe() adds a const struct ieee1394_device_id *id argument,
indicating the entry in the driver's device identifiers table which
matched the fw_unit to be probed. This new argument is used by the
snd-firewire-speakers driver to look up device-specific parameters and
methods. There is at least one other FireWire audio driver currently in
development in which this will be useful too.

The new .remove() drops the unused error return code.

Although all in-tree drivers are being converted to the new methods,
support for the old methods is left in place in this commit. This
allows public developer trees to merge this commit and then move to the
new fw_driver methods.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Clemens Ladisch <clemens@ladisch.de> (for sound/firewire/)
Cc: Peter Hurley <peter@hurleysoftware.com> (for drivers/staging/fwserial/)

firewire: remove unnecessary alloc/OOM messages

These are redundant to log messages from the mm core.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: convert to idr_alloc()

Convert to the much saner new idr interface.

v2: Stefan pointed out that add_client_resource() may be called from
non-process context. Preload iff @gfp_mask contains __GFP_WAIT.
Also updated to include minor upper limit check.

[tim.gardner@canonical.com: fix accidentally orphaned 'minor'[
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

firewire: add minor number range check to fw_device_init()

fw_device_init() didn't check whether the allocated minor number isn't
too large. Fail if it goes overflows MINORBITS.

Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

firewire: core: feed /dev/random with devices' GUIDs

Send the GUIDs of newly registered controllers and devices
to the /dev/random driver to help seed its pools.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: add is_local sysfs device attribute

Making this information available in sysfs allows to differentiate
between controllers in the local and remote Linux PCs, and thus is
useful for servers that are started with udev rules.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: fw_device_refresh(): clean up error handling

In fw_device_init() and fw_device_refresh(), if a call to
read_cofig_rom() fails, the operation is retried a few times, with
these retries being controlled by the MAX_RETRIES and RETRY_DELAY
symbols.

fw_device_refresh() also reads part of the config rom by calling
reread_config_rom(). Any errors from this call resulted in retries
with MAX_RETRIES/2 and RETRY_DELAY/2.

There is no reason to require that a device that has initiated a bus
reset must react faster to read requests than a device that has just
been plugged in. Furthermore, if the config rom has changed, any
errors from the following read_config_rom() call are then handled
with the normal retry count and delay.

Remove this inconsistency by always using the normal retry count and
delay. (This also makes the two error handlers identical and allows
merging them.)

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: log config rom reading errors

If reading or refreshing a config rom fails, also log the actual error
that caused it to fail.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: improve reread_config_rom() interface

The return value of reread_config_rom() was a mixture of two pieces of
information: whether the function succeeded, and whether the config rom
had changed.

To clarify the semantics, and to allow returning the actual error code,
split the second information into a new output parameter.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: wait for inaccessible devices after bus reset

When reread_config_rom() encountered a config rom that was marked as not
yet accessible, that device would be treated as "gone". This would mean
that that device would effectively vanish until the next bus reset.

The correct way to handle this situation is the same as in
read_config_rom(), to treat this like other errors and to retry the read
later, when the (possibly changed) config rom is available. The device
is marked "gone" only if it continues to return zero values after these
retries.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Remove all #inclusions of asm/system.h

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it. Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`

Signed-off-by: David Howells <dhowells@redhat.com>

firewire: core: prefix log messages with card name

Associate all log messages from firewire-core with the respective card
because some people have more than one card. E.g.
firewire_ohci 0000:04:00.0: added OHCI v1.10 device as card 0, 8 IR + 8 IT contexts, quirks 0x0
firewire_ohci 0000:05:00.0: added OHCI v1.10 device as card 1, 8 IR + 8 IT contexts, quirks 0x0
firewire_core: created device fw0: GUID 0814438400000389, S800
firewire_core: phy config: new root=ffc1, gap_count=5
firewire_core: created device fw1: GUID 0814438400000388, S800
firewire_core: created device fw2: GUID 0001d202e06800d1, S800
turns into
firewire_ohci 0000:04:00.0: added OHCI v1.10 device as card 0, 8 IR + 8 IT contexts, quirks 0x0
firewire_ohci 0000:05:00.0: added OHCI v1.10 device as card 1, 8 IR + 8 IT contexts, quirks 0x0
firewire_core 0000:04:00.0: created device fw0: GUID 0814438400000389, S800
firewire_core 0000:04:00.0: phy config: new root=ffc1, gap_count=5
firewire_core 0000:05:00.0: created device fw1: GUID 0814438400000388, S800
firewire_core 0000:04:00.0: created device fw2: GUID 0001d202e06800d1, S800

This increases the module size slightly; to keep this in check, turn the
former printk wrapper macros into functions. Their implementation is
largely copied from driver core's dev_printk counterparts.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: move fw_device reference counting from drivers to core

fw_unit device drivers invariably need to talk to the fw_unit's parent
(an fw_device) and grandparent (an fw_card). firewire-core already
maintains an fw_card reference for the entire lifetime of an fw_device.
Likewise, let firewire-core maintain an fw_device reference for the
entire lifetime of an fw_unit so that fw_unit drivers don't have to.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: handle ack_busy when fetching the Config ROM

Some older Panasonic made camcorders (Panasonic AG-EZ30 and NV-DX110,
Grundig Scenos DLC 2000) reject requests with ack_busy_X if a request is
sent immediately after they sent a response to a prior transaction.
This causes firewire-core to fail probing of the camcorder with "giving
up on config rom for node id ...". Consequently, programs like kino or
dvgrab are unaware of the presence of a camcorder.

Such transaction failures happen also with the ieee1394 driver stack
(of the 2.4...2.6 kernel series until 2.6.36 inclusive) but with a lower
likelihood, such that kino or dvgrab are generally able to use these
camcorders via the older driver stack. The cause for firewire-ohci's or
firewire-core's worse behavior is not yet known. Gap count optimization
in firewire-core is not the cause. Perhaps the slightly higher latency
of transaction completion in the older stack plays a role. (ieee1394:
AR-resp DMA context tasklet -> packet completion ktread -> user process;
firewire-core: tasklet -> user process.)

This change introduces retries and delays after ack_busy_X into
firewire-core's Config ROM reader, such that at least firewire-core's
probing and /dev/fw* creation are successful. This still leaves the
problem that userland processes are facing transaction failures.
gscanbus's built-in retry routines deal with them successfully, but
neither kino's nor dvgrab's do ever succeed.

But at least DV capture with "dvgrab -noavc -card 0" works now. Live
video preview in kino works too, but not actual capture.

One way to prevent Configuration ROM reading failures in application
programs is to modify libraw1394 to synthesize read responses by means
of firewire-core's Configuration ROM cache. This would only leave
CMP and FCP transaction failures as a potential problem source for
applications.

Reported-and-tested-by: Thomas Seilund <tps@netmaster.dk>
Reported-and-tested-by: René Fritz <rene@colorcube.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

atomic: use <linux/atomic.h>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

firewire: sbp2: parallelize login, reconnect, logout

The struct sbp2_logical_unit.work items can all be executed in parallel
but are not reentrant. Furthermore, reconnect or re-login work must be
executed in a WQ_MEM_RECLAIM workqueue.

Hence replace the old single-threaded firewire-sbp2 workqueue by a
concurrency-managed but non-reentrant workqueue with rescuer.
firewire-core already maintains one, hence use this one.

In earlier versions of this change, I observed occasional failures of
parallel INQUIRY to an Initio INIC-2430 FireWire 800 to dual IDE bridge.
More testing indicates that parallel INQUIRY is not actually a problem,
but too quick successions of logout and login + INQUIRY, e.g. a quick
sequence of cable plugout and plugin, can result in failed INQUIRY.
This does not seem to be something that should or could be addressed by
serialization.

Another dual-LU device to which I currently have access to, an
OXUF924DSB FireWire 800 to dual SATA bridge with firmware from MacPower,
has been successfully tested with this too.

This change is beneficial to environments with two or more FireWire
storage devices, especially if they are located on the same bus.
Management tasks that should be performed as soon and as quickly as
possible, especially reconnect, are no longer held up by tasks on other
devices that may take a long time, especially login with INQUIRY and sd
or sr driver probe.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: use non-reentrant workqueue with rescuer

firewire-core manages the following types of work items:

fw_card.br_work:
- resets the bus on a card and possibly sends a PHY packet before that
- does not sleep for long or not at all
- is scheduled via fw_schedule_bus_reset() by
- firewire-ohci's pci_probe method
- firewire-ohci's set_config_rom method, called by kernelspace
protocol drivers and userspace drivers which add/remove
Configuration ROM descriptors
- userspace drivers which use the bus reset ioctl
- itself if the last reset happened less than 2 seconds ago

fw_card.bm_work:
- performs bus management duties
- usually does not (but may in corner cases) sleep for long
- is scheduled via fw_schedule_bm_work() by
- firewire-ohci's self-ID-complete IRQ handler tasklet
- firewire-core's fw_device.work instances whenever the root node
device was (successfully or unsuccessfully) discovered,
refreshed, or rediscovered
- itself in case of resource allocation failures or in order to
obey the 125ms bus manager arbitration interval

fw_device.work:
- performs node probe, update, shutdown, revival, removal; including
kernel driver probe, update, shutdown and bus reset notification to
userspace drivers
- usually sleeps moderately long, in corner cases very long
- is scheduled by
- firewire-ohci's self-ID-complete IRQ handler tasklet via the
core's fw_node_event
- firewire-ohci's pci_remove method via core's fw_destroy_nodes/
fw_node_event
- itself during retries, e.g. while a node is powering up

iso_resource.work:
- accesses registers at the Isochronous Resource Manager node
- usually does not (but may in corner cases) sleep for long
- is scheduled via schedule_iso_resource() by
- the owning userspace driver at addition and removal of the
resource
- firewire-core's fw_device.work instances after bus reset
- itself in case of resource allocation if necessary to obey the
1000ms reallocation period after bus reset

fw_card.br_work instances should not, and instances of the others must
not, be executed in parallel by multiple CPUs -- but were not protected
against that. Hence allocate a non-reentrant workqueue for them.

fw_device.work may be used in the memory reclaim path in case of SBP-2
device updates. Hence we need a workqueue with rescuer and cannot use
system_nrt_wq.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Reviewed-by: Tejun Heo <tj@kernel.org>

firewire: core: ignore link-active bit of new nodes, fix device recognition

Like the older ieee1394 core driver, firewire-core skipped scanning of
any new node whose PHY sent a self ID without "link active" bit. If a
device had this bit off mistakenly, it meant that it was inaccessible to
kernel drivers with the old IEEE 1394 driver stack but could still be
accessed by userspace drivers through the raw1394 interface.

But with firewire-core, userspace drivers don't get to see such buggy
devices anymore. This is effectively a driver regression since this
device bug is otherwise harmless.

We now attempt to scan all devices, even repeaters that don't have a
link or powered-down devices that have everything but their PHY shut
down when plugged in. This results in futile repeated scanning attempts
in case of such devices that really don't have an active link, but this
doesn't hurt since recent workqueue infrastructure lets us run more
concurrent scanning jobs than we can shake a stick at.

This should fix accessibility of Focusrite Saffire PRO 26 I/O:
http://sourceforge.net/mailarchive/forum.php?thread_name=20110314215622.5c751bb0%40stein&forum_name=ffado-user

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: fix card->reset_jiffies overflow

On a 32-bit machine with, e.g., HZ=1000, jiffies will overflow after
about 50 days, so if there are between 25 and 50 days between bus
resets, the card->reset_jiffies comparisons can get wrong results.

To fix this, ensure that this timestamp always uses 64 bits.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: "Stefan Richter" <stefanr@s5r6.in-berlin.de>

firewire: cdev: fix fw_cdev_event_bus_reset emission after local config ROM changes

When a descriptor was added or removed to the local node's config ROM,
userspace clients which had a local node's /dev/fw* open did not receive
any fw_cdev_event_bus_reset for poll()/read() consumption.

The cause was that the core-device.c facility which re-reads the config
ROM of the bus reset initiator node missed to call the fw_device update
function. The fw_units are destroyed and newly added, but their parent
stays and needs to be updated.

Reported-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: fix fw_send_request kerneldoc comment

The present inline documentation of the fw_send_request() in-kernel API
refers to userland code that is not applicable to kernel drivers at all.

Reported-by: Ben Gamari <bgamari.foss@gmail.com>

While we are at fixing the whole documentation of fw_send_request(),
also improve the rest of firewire-core's kerneldoc comments:
- Add a bit of text concerning fw_run_transaction()'s call parameters.
- Append () to function names and tab-align parameter descriptions as
suggested by the example in Documentation/kernel-doc-nano-HOWTO.txt.
- Remove kerneldoc markers from comments on static functions.
- Remove outdated parameter descriptions at build_tree().

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

firewire: core: align driver match with modalias

The driver match strategy was:
- Match vendor/model/specifier/version of the unit directory.
- If that was a miss, match vendor from the root directory and
model/specifier/version of the unit directory.

This was inconsistent with how the modalias string was constructed
until recently (take vendor/model from root directory and specifier/
version from unit directory). It was also inconsistent with how it is
done since the parent commit:
- Use vendor/model/specifier/version of the unit directory if possible,
- fall back to one or more of vendor/model/specifier/version from the
root directory depending on which ones are not present at the unit
directory.

Fix this inconsistency by sharing the ROM scanner function between
modalias printer function and driver match function.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: fix Model_ID in modalias

The modalias string of devices that represent units on a FireWire node
did not show Module_ID entries within unit directories. This was
because firewire-core searched only the root directory of the
configuration ROM for a Model_ID entry.

We now search first the root directory, then the unit directory. IOW
honor a unit directory's Model_ID if present, otherwise fall back to the
root directory's model ID (if present).

Furthermore, apply the same change to Vendor_ID. This had the same
issue but it was less apparent because most devices provide Vendor_ID
only in the root directory.

And finally, also use this strategy for the remaining two IDs in the
modalias, Specifier_ID and Version. It does not actually make sense to
look for them elsewhere than in the unit directory because they are
mandatory there. However, a uniform search order simplifies the
implementation and has no adverse affect in practice.

Side notes:
- The older counterpart of this, nodemgr.c of ieee1394, looked for
Vendor_ID first in the root directory, then in the unit directory,
and for Model_ID only in the unit directory.
- There is a single mainline driver which requires Vendor_ID and
Model_ID --- the firedtv driver. This one worked because FireDTVs
provide Vendor_ID in the root directory and Model_ID identically in
root directory and unit directory.
- Apart from firedtv, there are currently no drivers known to me
(including userspace drivers) that look at the Vendor_ID or Model_ID
of the modalias.

Reported-by: Maciej Żenczykowski <zenczykowski@gmail.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Driver core: create lock/unlock functions for struct device

In the future, we are going to be changing the lock type for struct
device (once we get the lockdep infrastructure properly worked out) To
make that changeover easier, and to possibly burry the lock in a
different part of struct device, let's create some functions to lock and
unlock a device so that no out-of-core code needs to be changed in the
future.

This patch creates the device_lock/unlock/trylock() functions, and
converts all in-tree users to them.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Cc: Magnus Damm <damm@igel.co.jp>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Alex Chiang <achiang@hp.com>
Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrew Patterson <andrew.patterson@hp.com>
Cc: Yu Zhao <yu.zhao@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: CHENG Renquan <rqcheng@smu.edu.sg>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Frans Pop <elendil@planet.nl>
Cc: David Vrabel <david.vrabel@csr.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

firewire: core: rename an internal function

according to what it really does.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: fix an information leak

If a device exposes a sparsely populated configuration ROM,
firewire-core's sysfs interface and character device file interface
showed random data in the gaps between config ROM blocks. Fix this by
zero-initialization of the config ROM reader's scratch buffer.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: increase stack size of config ROM reader

The stack size of 16 was artificially chosen and may be too small in
extreme cases. A device won't be accessible then.

Since it doesn't really matter to the slab allocator whether we ask for
1088 bytes or 2048 bytes of scratch memory, just allocate 2048 bytes for
the sum of temporary config ROM image and stack, and we will never ever
overflow the stack (because there simply can't be more stack items than
ROM entries).

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: don't fail device creation in case of too large config ROM blocks

It never happened yet, but better safe than sorry: If a device's config
ROM contains a block which overlaps the boundary at 0xfffff00007ff, just
ignore that one block instead of refusing to add the device
representation. That way, upper layers (kernelspace or userspace
drivers) might still be able to use the device to some degree.

That's better than total inaccessibility of the device. Worse, the core
would have logged only a generic "giving up on config rom" message which
could only be debugged by feeding a firewire-ohci debug logging session
through a config ROM interpreter, IOW would likely remain undiagnosed.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: fix "giving up on config rom" with Panasonic AG-DV2500

The Panasonic AG-DV2500 tape deck contains an invalid entry in its
configuration ROM root directory: A leaf pointer with the undefined key
ID 0 and an offset that points way out of the standard config ROM area.
This caused firewire-core to dismiss the device with the generic log
message "giving up on config rom for node id...", after which it was of
course impossible to access the tape deck with dvgrab or any other
program. https://bugzilla.redhat.com/show_bug.cgi?id=449252#c29

The fix is to simply ignore this invalid ROM entry and proceed to read
the valid rest of the ROM. There is a catch though: When the kernel
later iterates over the ROM, it would be nasty having to check again for
such too large ROM offsets. Therefore we manipulate the defective or
unsupported ROM entry to become a harmless immediate entry that won't
have any side effects later (an entry with the value 0x00000000).

Reported-by: George Chriss
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: qualify config ROM cache pointers as const pointers

Several config ROM related functions only peek at the ROM cache; mark
their arguments as const pointers. Ditto fw_device.config_rom and
fw_unit.directory, as the memory behind them is meant to be write-once.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: fw_csr_string addendum

Witespace and comment changes, and a different way to say i + 1 < end.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: add fw_csr_string() helper function

The core (sysfs attributes), the firedtv driver, and possible future
drivers all read strings from some configuration ROM directory. Factor
out the generic code from show_text_leaf() into a new helper function,
modified slightly to handle arbitrary buffer sizes.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

driver model: constify attribute groups

Let attribute group vectors be declared "const". We'd
like to let most attribute metadata live in read-only
sections... this is a start.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

firewire: core: don't update Broadcast_Channel if RFC 2734 conditions aren't met

This extra check will avoid Broadcast_Channel register related traffic
to many IIDC, SBP-2, and AV/C devices which aren't IRMC or have a
max_rec < 8 (i.e. support < 512 bytes async payload). This avoids a
little bit of traffic after bus reset and is even more careful with
devices which don't implement this CSR.

The assumption is that no other protocol than IP over 1394 uses the
broadcast channel for streams.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: core: prepare for non-core children of card devices

The IP-over-1394 driver will add child devices beneath card devices
which are not of type fw_device. Hence firewire-core's callbacks in
device_for_each_child() and device_find_child() need to check for the
device type now.

Initial version written by Jay Fenlason.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: add parent-of-unit accessor

Retrieval of an fw_unit's parent is a common pattern in high-level code.
Wrap it up as device = fw_parent_device(unit).

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

firewire: rename source files

The source files of firewire-core, firewire-ohci, firewire-sbp2, i.e.
"drivers/firewire/fw-*.c"
are renamed to
"drivers/firewire/core-*.c",
"drivers/firewire/ohci.c",
"drivers/firewire/sbp2.c".

The old fw- prefix was redundant to the directory name. The new core-
prefix distinguishes the files according to which driver they belong to.

This change comes a little late, but still before further firewire
drivers are added as anticipated RSN.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>