As a result of heavy refactoring based on IR context header, the packet
handler becomes simpler.

This commit merges the packet handler into function for IR context
callback. The logic to parse IR context header and tracepoints event is
split to a function.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

As a result of heavy refactoring based on IT packet header, the packet
handler becomes simpler.

This commit merges the packet handler into function for IT context
callback. The logic to build IT packet header and tracepoints event is
split to a function.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The value of data block counter is not calculated for incoming packet
without CIP header. This commit fixes the bug.

Fixes: 947b437e ("ALSA: firewire-lib: unify packet handler for IR context")
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In Linux firewire subsystem, for IT context, some quadlets of isochronous
packet payload can be indicated as a part of packet header to queue to
the context.

This commit uses the packet header to split CIP headers from CIP
payload. As a result, regardless of CIP or non-CIP, context payload
includes data blocks only.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

This commit is a preparation to queue IT packet with header. To enable
packet handler to fill the header, this commit uses kernel stack for
data structure of packet parameter in several part of this file.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The handlers for packet with CIP and without CIP include common codes.
This commit unifies them and remove an member for pointer to callback
function from data structure.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

This is minor code refactoring to split a function to generate CIP
header.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Usage of 16 bytes IR context header allows to handle context payload by
the same code for with-CIP and without-CIP packets.

This commit unifies both handlers of with-CIP and without-CIP packets.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In IR context, some quadlets of packet payload can be included into
context header. This is good for packet with CIP header because the
context payload buffer can includes data blocks only for with-CIP and
without-CIP pakets.

This commit uses 16 bytes IR context header for this purpose.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

A parser for CIP header in incoming packet is enough large.

This commit splits it into a helper function to better looks of packet
handler.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The value of pointer to payload buffer is computed in each packet
handler, however the pointer can be decided before call of packet
handler.

This commit adds an argument for the pointer to the packet handler to
reduce codes to compute for the pointer.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In current packet handler, the length of payload is given as an argument
of callback function, however this value is just required to process
payload of transferred isoc packet, thus just for IR context.

This commit replaces the argument for payload of packet with the
argument of context header. As a result, the length of payload is
computed in packet handler for IR context.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

This commit is to distinguish variable of CIP header from variable of
isochronous context header.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In IT context, header includes information of cycle to have processed
queued packet.

This commit uses the per-packet information to compute the cycle for
packet to be queued, instead of callback argument. In current
implementaion of ALSA IEC 61883-1/6 packet streaming engine, 48 packets
are queued at first to skip recent cycle. When IT context calls handler,
cycle information in header plus 48 cycle means the cycle to be going
to queue packet.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The header size parameter of 1394 OHCI IT context has no effect.
Besides the header size of queued packet is different from context
header.

This commit cleans codes relevant to these two headers.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In callback handler of isochronous context for both direction, there're
common codes to cancel context.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Some parameters of struct amdtp_stream is dependent on direction.

This commit uses union for such parameters to distinguish from
common parameters.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Now four events of this module have the same arguments and probe timing.
This commit adds a new event, 'amdtp_packet', and replace them. Filtering
functionality of tracing framework is available to pick up events for
inbound/outbound isochronous packets.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The most of tracing event in this module have the size of payload in
byte unit, however 'in_packet_without_header' event have the argument
in quadlet unit.

This commit change the unit for argument to be consistent.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: add data_blocks/data_block_counter parameter to in_packet/out_packet tracing events

Tracing events for packets without CIP header have a parameter of
data_blocks/data_block_counter, but events for packets with CIP header
don't. This is not good to unify these events.

This commit adds the missing parameters to the events. In timing to
probe 'in_packet' event, data_blocks and data_block_counter are not
calculated yet. This commit also changes the timing.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

An argument for CIP header in 'in_packet' event is not the same type in
'out_packet' event. This is not good to unify these events.

This commit uses the same type of argument for these events.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In kernel API of Linux FireWire subsystem, handlers of isochronous
receive (IR) context can get context headers as an argument of
callback. When 4 byte header is used, the context header includes
isochronous packet header for each packet. When 8 byte header is
used, it includes isochronous cycle as well.

ALSA IEC 61883-1/6 engine uses 4 byte header, and computes isochronous
cycle from the cycle of interrupt. The usage of 8 byte header can
obsolete the computation.

Furthermore, this change works well for a case that a series of
packet in one interrupt includes skipped isochronous cycle,

This commit uses 8 byte header to handle isochronous cycle.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In IEC 61883-1/6 engine of ALSA firewire stack, a packet handler has a
second argument for 'the number of bytes in payload of isochronous
packet'. However, an incoming packet handler without CIP header uses the
value as 'the number of quadlets in the payload'. This brings userspace
applications to receive the number of PCM frames as four times against
real time.

This commit fixes the bug.

Cc: <stable@vger.kernel.org> # v4.12+
Fixes: 3b196c39 ('ALSA: firewire-lib: add no-header packet processing')
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In a former commit, PCM constraint based on LCM of SYT_INTERVAL was
obsoleted with PCM rule. However, the new PCM rule brings -EINVAL in
some cases that max/min values of size of buffer/period is not
multiples of one of values of SYT_INTERVAL. For example, pulseaudio
always fail to configure PCM substream.

This commit changes strategy for the PCM rule. Although the buggy rules
had a single dependency (rate from period, period from rate, rate from
buffer, buffer from rate), a revised rule has double dependencies
(period from period/rate, buffer from buffer/rate). A step of value is
calculated with table of SYT_INTERVAL and list of available rates. This
prevents interval template which brings -EINVAL to a call of
snd_interval_refine().

Fixes: 59502295('ALSA: firewire-lib: add PCM rules to obsolete PCM constraints based on LCM of SYT_INTERVAL')
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In blocking mode of IEC 61883-1/6, when one isochronous packet includes
data for events, the data is for the same number of events as
SYT_INTERVAL decided according to sampling transmission frequency (SFC).

IEC 61883-1/6 engine of ALSA firewire stack applies constraints of
period and buffer size of PCM intermediate buffer of PCM substream.
At present, this constraint is designed to round the size up/down to
32 frames. This value comes from the least common multiple (LCM) of
SYT_INTERVAL. Although this looks to work well, in lower sampling
rate, applications are not allowed to set size of period quite near
period time constraint (at present 5 msec per period).

This commit adds PCM rules for period/buffer size and rate to obsoletes
the constraints based on LCM.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

At a commit f91c9d76 ('ALSA: firewire-lib: cache maximum length of
payload to reduce function calls'), maximum size of payload for tx
isochronous packet is cached to reduce the number of function calls.

This cache was programmed to updated at a first callback of ohci1394 IR
context. However, the maximum size is required to queueing packets before
starting the isochronous context.

As a result, the cached value is reused to queue packets in next time to
starting the isochronous context. Then the cache is updated in a first
callback of the isochronous context. This can cause kernel NULL pointer
dereference in a below call graph:

(sound/firewire/amdtp-stream.c)
amdtp_stream_start()
->queue_in_packet()
  ->queue_packet()
    (drivers/firewire/core-iso.c)
    ->fw_iso_context_queue()
      ->struct fw_card_driver.queue_iso()
      (drivers/firewire/ohci.c)
      = ohci_queue_iso()
        ->queue_iso_packet_per_buffer()
          buffer->pages[page]

The issued dereference occurs in a case that:
 - target unit supports different stream formats for sampling transmission
   frequency.
 - maximum length of payload for tx stream in a first trial is bigger
   than the length in a second trial.

In this case, correct number of pages are allocated for DMA and the 'pages'
array has enough elements, while index of the element is wrongly calculated
according to the old value of length of payload in a call of
'queue_in_packet()'. Then it causes the issue.

This commit fixes the critical bug. This affects all of drivers in ALSA
firewire stack in Linux kernel v4.12 or later.

[12665.302360] BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
[12665.302415] IP: ohci_queue_iso+0x47c/0x800 [firewire_ohci]
[12665.302439] PGD 0
[12665.302440] P4D 0
[12665.302450]
[12665.302470] Oops: 0000 [#1] SMP PTI
[12665.302487] Modules linked in: ...
[12665.303096] CPU: 1 PID: 12760 Comm: jackd Tainted: P           OE   4.13.0-38-generic #43-Ubuntu
[12665.303154] Hardware name:                  /DH77DF, BIOS KCH7710H.86A.0069.2012.0224.1825 02/24/2012
[12665.303215] task: ffff9ce87da2ae80 task.stack: ffffb5b8823d0000
[12665.303258] RIP: 0010:ohci_queue_iso+0x47c/0x800 [firewire_ohci]
[12665.303301] RSP: 0018:ffffb5b8823d3ab8 EFLAGS: 00010086
[12665.303337] RAX: ffff9ce4f4876930 RBX: 0000000000000008 RCX: ffff9ce88a3955e0
[12665.303384] RDX: 0000000000000000 RSI: 0000000034877f00 RDI: 0000000000000000
[12665.303427] RBP: ffffb5b8823d3b68 R08: ffff9ce8ccb390a0 R09: ffff9ce877639ab0
[12665.303475] R10: 0000000000000108 R11: 0000000000000000 R12: 0000000000000003
[12665.303513] R13: 0000000000000000 R14: ffff9ce4f4876950 R15: 0000000000000000
[12665.303554] FS:  00007f2ec467f8c0(0000) GS:ffff9ce8df280000(0000) knlGS:0000000000000000
[12665.303600] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[12665.303633] CR2: 0000000000000030 CR3: 00000002dcf90004 CR4: 00000000000606e0
[12665.303674] Call Trace:
[12665.303698]  fw_iso_context_queue+0x18/0x20 [firewire_core]
[12665.303735]  queue_packet+0x88/0xe0 [snd_firewire_lib]
[12665.303770]  amdtp_stream_start+0x19b/0x270 [snd_firewire_lib]
[12665.303811]  start_streams+0x276/0x3c0 [snd_dice]
[12665.303840]  snd_dice_stream_start_duplex+0x1bf/0x480 [snd_dice]
[12665.303882]  ? vma_gap_callbacks_rotate+0x1e/0x30
[12665.303914]  ? __rb_insert_augmented+0xab/0x240
[12665.303936]  capture_prepare+0x3c/0x70 [snd_dice]
[12665.303961]  snd_pcm_do_prepare+0x1d/0x30 [snd_pcm]
[12665.303985]  snd_pcm_action_single+0x3b/0x90 [snd_pcm]
[12665.304009]  snd_pcm_action_nonatomic+0x68/0x70 [snd_pcm]
[12665.304035]  snd_pcm_prepare+0x68/0x90 [snd_pcm]
[12665.304058]  snd_pcm_common_ioctl1+0x4c0/0x940 [snd_pcm]
[12665.304083]  snd_pcm_capture_ioctl1+0x19b/0x250 [snd_pcm]
[12665.304108]  snd_pcm_capture_ioctl+0x27/0x40 [snd_pcm]
[12665.304131]  do_vfs_ioctl+0xa8/0x630
[12665.304148]  ? entry_SYSCALL_64_after_hwframe+0xe9/0x139
[12665.304172]  ? entry_SYSCALL_64_after_hwframe+0xe2/0x139
[12665.304195]  ? entry_SYSCALL_64_after_hwframe+0xdb/0x139
[12665.304218]  ? entry_SYSCALL_64_after_hwframe+0xd4/0x139
[12665.304242]  ? entry_SYSCALL_64_after_hwframe+0xcd/0x139
[12665.304265]  ? entry_SYSCALL_64_after_hwframe+0xc6/0x139
[12665.304288]  ? entry_SYSCALL_64_after_hwframe+0xbf/0x139
[12665.304312]  ? entry_SYSCALL_64_after_hwframe+0xb8/0x139
[12665.304335]  ? entry_SYSCALL_64_after_hwframe+0xb1/0x139
[12665.304358]  SyS_ioctl+0x79/0x90
[12665.304374]  ? entry_SYSCALL_64_after_hwframe+0x72/0x139
[12665.304397]  entry_SYSCALL_64_fastpath+0x24/0xab
[12665.304417] RIP: 0033:0x7f2ec3750ef7
[12665.304433] RSP: 002b:00007fff99e31388 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[12665.304465] RAX: ffffffffffffffda RBX: 00007fff99e312f0 RCX: 00007f2ec3750ef7
[12665.304494] RDX: 0000000000000000 RSI: 0000000000004140 RDI: 0000000000000007
[12665.304522] RBP: 0000556ebc63fd60 R08: 0000556ebc640560 R09: 0000000000000000
[12665.304553] R10: 0000000000000001 R11: 0000000000000246 R12: 0000556ebc63fcf0
[12665.304584] R13: 0000000000000000 R14: 0000000000000007 R15: 0000000000000000
[12665.304612] Code: 01 00 00 44 89 eb 45 31 ed 45 31 db 66 41 89 1e 66 41 89 5e 0c 66 45 89 5e 0e 49 8b 49 08 49 63 d4 4d 85 c0 49 63 ff 48 8b 14 d1 <48> 8b 72 30 41 8d 14 37 41 89 56 04 48 63 d3 0f 84 ce 00 00 00
[12665.304713] RIP: ohci_queue_iso+0x47c/0x800 [firewire_ohci] RSP: ffffb5b8823d3ab8
[12665.304743] CR2: 0000000000000030
[12665.317701] ---[ end trace 9d55b056dd52a19f ]---

Fixes: f91c9d76 ('ALSA: firewire-lib: cache maximum length of payload to reduce function calls')
Cc: <stable@vger.kernel.org> # v4.12+
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE()

Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.

For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.

However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:

----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()

// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch

virtual patch

@ depends on patch @
expression E1, E2;
@@

- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)

@ depends on patch @
expression E;
@@

- ACCESS_ONCE(E)
+ READ_ONCE(E)
----
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

At Linux v3.5, packet processing can be done in process context of ALSA
PCM application as well as software IRQ context for OHCI 1394. Below is
an example of the callgraph (some calls are omitted).

ioctl(2) with e.g. HWSYNC
(sound/core/pcm_native.c)
->snd_pcm_common_ioctl1()
  ->snd_pcm_hwsync()
    ->snd_pcm_stream_lock_irq
    (sound/core/pcm_lib.c)
    ->snd_pcm_update_hw_ptr()
      ->snd_pcm_udpate_hw_ptr0()
        ->struct snd_pcm_ops.pointer()
        (sound/firewire/*)
        = Each handler on drivers in ALSA firewire stack
          (sound/firewire/amdtp-stream.c)
          ->amdtp_stream_pcm_pointer()
            (drivers/firewire/core-iso.c)
            ->fw_iso_context_flush_completions()
              ->struct fw_card_driver.flush_iso_completion()
              (drivers/firewire/ohci.c)
              = flush_iso_completions()
                ->struct fw_iso_context.callback.sc
                (sound/firewire/amdtp-stream.c)
                = in_stream_callback() or out_stream_callback()
                  ->...
    ->snd_pcm_stream_unlock_irq

When packet queueing error occurs or detecting invalid packets in
'in_stream_callback()' or 'out_stream_callback()', 'snd_pcm_stop_xrun()'
is called on local CPU with disabled IRQ.

(sound/firewire/amdtp-stream.c)
in_stream_callback() or out_stream_callback()
->amdtp_stream_pcm_abort()
  ->snd_pcm_stop_xrun()
    ->snd_pcm_stream_lock_irqsave()
    ->snd_pcm_stop()
    ->snd_pcm_stream_unlock_irqrestore()

The process is stalled on the CPU due to attempt to acquire recursive lock.

[  562.630853] INFO: rcu_sched detected stalls on CPUs/tasks:
[  562.630861]      2-...: (1 GPs behind) idle=37d/140000000000000/0 softirq=38323/38323 fqs=7140
[  562.630862]      (detected by 3, t=15002 jiffies, g=21036, c=21035, q=5933)
[  562.630866] Task dump for CPU 2:
[  562.630867] alsa-source-OXF R  running task        0  6619      1 0x00000008
[  562.630870] Call Trace:
[  562.630876]  ? vt_console_print+0x79/0x3e0
[  562.630880]  ? msg_print_text+0x9d/0x100
[  562.630883]  ? up+0x32/0x50
[  562.630885]  ? irq_work_queue+0x8d/0xa0
[  562.630886]  ? console_unlock+0x2b6/0x4b0
[  562.630888]  ? vprintk_emit+0x312/0x4a0
[  562.630892]  ? dev_vprintk_emit+0xbf/0x230
[  562.630895]  ? do_sys_poll+0x37a/0x550
[  562.630897]  ? dev_printk_emit+0x4e/0x70
[  562.630900]  ? __dev_printk+0x3c/0x80
[  562.630903]  ? _raw_spin_lock+0x20/0x30
[  562.630909]  ? snd_pcm_stream_lock+0x31/0x50 [snd_pcm]
[  562.630914]  ? _snd_pcm_stream_lock_irqsave+0x2e/0x40 [snd_pcm]
[  562.630918]  ? snd_pcm_stop_xrun+0x16/0x70 [snd_pcm]
[  562.630922]  ? in_stream_callback+0x3e6/0x450 [snd_firewire_lib]
[  562.630925]  ? handle_ir_packet_per_buffer+0x8e/0x1a0 [firewire_ohci]
[  562.630928]  ? ohci_flush_iso_completions+0xa3/0x130 [firewire_ohci]
[  562.630932]  ? fw_iso_context_flush_completions+0x15/0x20 [firewire_core]
[  562.630935]  ? amdtp_stream_pcm_pointer+0x2d/0x40 [snd_firewire_lib]
[  562.630938]  ? pcm_capture_pointer+0x19/0x20 [snd_oxfw]
[  562.630943]  ? snd_pcm_update_hw_ptr0+0x47/0x3d0 [snd_pcm]
[  562.630945]  ? poll_select_copy_remaining+0x150/0x150
[  562.630947]  ? poll_select_copy_remaining+0x150/0x150
[  562.630952]  ? snd_pcm_update_hw_ptr+0x10/0x20 [snd_pcm]
[  562.630956]  ? snd_pcm_hwsync+0x45/0xb0 [snd_pcm]
[  562.630960]  ? snd_pcm_common_ioctl1+0x1ff/0xc90 [snd_pcm]
[  562.630962]  ? futex_wake+0x90/0x170
[  562.630966]  ? snd_pcm_capture_ioctl1+0x136/0x260 [snd_pcm]
[  562.630970]  ? snd_pcm_capture_ioctl+0x27/0x40 [snd_pcm]
[  562.630972]  ? do_vfs_ioctl+0xa3/0x610
[  562.630974]  ? vfs_read+0x11b/0x130
[  562.630976]  ? SyS_ioctl+0x79/0x90
[  562.630978]  ? entry_SYSCALL_64_fastpath+0x1e/0xad

This commit fixes the above bug. This assumes two cases:
1. Any error is detected in software IRQ context of OHCI 1394 context.
In this case, PCM substream should be aborted in packet handler. On the
other hand, it should not be done in any process context. TO distinguish
these two context, use 'in_interrupt()' macro.
2. Any error is detect in process context of ALSA PCM application.
In this case, PCM substream should not be aborted in packet handler
because PCM substream lock is acquired. The task to abort PCM substream
should be done in ALSA PCM core. For this purpose, SNDRV_PCM_POS_XRUN is
returned at 'struct snd_pcm_ops.pointer()'.
Suggested-by: NClemens Ladisch <clemens@ladisch.de>
Fixes: e9148ddd("ALSA: firewire-lib: flush completed packets when reading PCM position")
Cc: <stable@vger.kernel.org> # 4.9+
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In ALSA firewire stack, 8 drivers uses IEC 61883-1/6 engine for data
transmission. They have common PCM info/constraints and duplicated codes.

This commit unifies the codes into fireiwre-lib.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In recent commit for ALSA PCM core, some arrangement is done for
'struct snd_pcm_ops.ack' callback. This is called when appl_ptr is
explicitly moved in intermediate buffer for PCM frames, except for
some cases described later.

For drivers in ALSA firewire stack, usage of this callback has a merit to
reduce latency between time of PCM frame queueing and handling actual
packets in recent isochronous cycle, because no need to wait for software
IRQ context from isochronous context of OHCI 1394.

If this works well in a case that mapped page frame is used for the
intermediate buffer, user process should execute some commands for ioctl(2)
to tell the number of handled PCM frames in the intermediate buffer just
after handling them. Therefore, at present, with a combination of below
conditions, this doesn't work as expected and user process should wait for
the software IRQ context as usual:
 - when ALSA PCM core judges page frame mapping is available for status
   data (struct snd_pcm_mmap_status) and control data
   (struct snd_pcm_mmap_control).
 - user process handles PCM frames by loop just with 'snd_pcm_mmap_begin()'
   and 'snd_pcm_mmap_commit()'.
 - user process uses PCM hw plugin in alsa-lib to operate I/O without
   'sync_ptr_ioctl' option.

Unfortunately, major use case include these three conditions.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

During packet streaming, maximum length of payload for isochronous packet
is invariable, therefore no need to recalculate. Current ALSA IEC 61883-1/6
engine calls a function to calculate it 8,000 or more times per second
for incoming packet processing.

This commit adds a member to have maximum length of payload into 'struct
amdtp_stream', to reduces the function calls. At first callback from
isochronous context, the length is calculated and stored for later
processing.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Unique protocol is used for RME Fireface series. In this protocol,
payload format for isochronous packet is not compliant to CIP in
IEC 61883-1/6. The packet includes data blocks just with data channels,
without headers and any metadata.

In previous commits, ALSA IEC 61883-1/6 engine supports this protocol.
However, tracepoints are not supported yet, unlike implementation for
IEC 61883-1/6 protocol. This commit adds support of tracepoints for
the protocol.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

As long as investigating Fireface 400, IEC 61883-1/6 is not applied to
its packet streaming protocol. Remarks of the specific protocol are:
 * Each packet doesn't include CIP headers.
 * 64,0 and 128,0 kHz are supported.
 * The device doesn't necessarily transmit 8,000 packets per second.
 * 0, 1, 2, 3 are used as tag for rx isochronous packets, however 0 is
   used for tx isochronous packets.

On the other hand, there's a common feature. The number of data blocks
transferred in a second is the same as sampling transmission frequency.
Current ALSA IEC 61883-1/6 engine already has a method to calculate it and
this driver can utilize it for rx packets, as well as tx packets.

This commit adds support for the transferring protocol. CIP_NO_HEADERS
flag is newly added. When this flag is set:
 * Both of 0 (without CIP header) and 1 (with CIP header) are used as tag
   to handle incoming isochronous packet.
 * 0 (without CIP header) is used as tag to transfer outgoing isochronous
   packet.
 * Skip CIP header evaluation.
 * Use unique way to calculate the quadlets of isochronous packet payload.

In ALSA PCM interface, 128.0 kHz is not supported, and the ALSA
IEC 61883-1/6 engine doesn't support 64.0 kHz. These modes are dropped.

The sequence of rx packet has a remarkable quirk about tag. This will be
described in later commits.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Audio and music units of RME Fireface series use its own protocol for
isochronous packets to transfer data. This protocol requires ALSA IEC
61883-1/6 engine to have alternative functions.

This commit is a preparation for the protocol.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In IEC 61883-1, when two quadlets CIP header is used, the most significant
bit in second CIP header stands. However, packets from units with MOTU
protocol version 3 have a quirk without this flag. Current packet streaming
layer handles this as protocol error.

This commit adds a new enumeration constant for this quirk, to handle MOTU
protocol version 3.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Commit c8bdf49b("ALSA: fireworks/firewire-lib: Add a quirk for the
meaning of dbc") adds CIP_DBC_IS_END_EVENT flag just for tx packets.
However, MOTU FireWire series has this quirk for rx packets.

This commit allows both directions with the flag.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In IEC 61883-1, CIP headers can have a SPH field. When a packet has 1 in
SPH field of its CIP header, the packet has a source packet headers. A
source packet header consists of 32 bit field (= 1 quadlet) and it
transfers time stamp, which is the same value as the lower 25 bits of the
IEEE 1394 CYCLE_TIMER register and the rest is zero.

This commit just supports source packet header field because IEC 61883-1
includes ambiguity the position of this header and its count. Each
protocol layer is allowed to have actual implementation according its
requirements.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Currently, packet streaming layer passes generated SYT value to data block
processing layer. However, this is not enough in a case that the data block
processing layer generates time stamps by its own ways.

For out-packet stream, the packet streaming layer guarantees 8,000 times
calls of data block processing layers per sec. Therefore, when cycle count
of the first packet is recorded, data block processing layers can calculate
own time stamps with the recorded value.

For the reason, this commit allows packet streaming layer to record the
first cycle count. Each data block processing layer can read the count by
accessing a member of structure for packet streaming layer.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

This reverts commit 6b7e95d1. This commit
is based on a concern about value of the given parameter. It's expected
to be ORed value with some enumeration-constants, thus often it can not be
one of the enumeration-constants. I understood that this is out of
specification and causes implementation-dependent issues.

In C language specification, enumerated type can be interpreted as an
integer type, in which all of enumeration-constants in corresponding
enumerator-list can be stored. Implementations can select one of char,
signed int and unsigned int as its type, and this selection is
implementation-dependent.

In GCC, a signed integer is selected when at least one of
enumeration-constants has negative value, else an unsigned integer is
selected. This behaviour can be switched by -fshort-enums to short type.
Anyway, the type can be decided after scanning all of
enumeration-constants.

Totally, there's no rules to constrain the value of enumerated type to
be one of enumeration-constants. In short, in enumerated type, decision
of actual type for the type is the most important and
enumeration-constants are just used for the decision, thus it's permitted
to have an integer value in a range of enumeration-constants. In our case,
actual type for the type is currently deterministic to be either char or
unsigned int. Under GCC, it's unsigned int.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The 'amdtp_stream' structure is initialized by a call of
'amdtp_stream_init()'. Although a parameter of this function is for bit
flags of packet attributes, its type is enumerator.

This commit changes the type so that it's proper for a bit flags.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>