Adding power gating introduced new waiting state for client also during
connection attempt, a connection request can be queued for later either due
device is power gated or due to other on going connection.
We setting client connection state before start of full connect procedure so
in both cased the client state will be MEI_FILE_CONNECTING
which create interlock between the two connection attempts, both
detecting that another connection is in progress.

The interlock is resolved by moving client to connecting state
only upon connection request transmission, so the  first
cb in queue can be processed.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Follow-up for bits missed in
commit 7ca96aa2
mei: make return values consistent across the driver
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Take rpm token on operation start to initiate rpm resume if needed.
Mark last busy time, release token and advice rpm framework
to try to autosuspend on operation end.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Write callbacks are released on the write completed path but
when file handler is closed before the writes are
completed those are left dangling on write and write_waiting queues.

We add mei_io_list_free function to perform this task

Also move static functions to client.c form client.h

Cc: stable <stable@vger.kernel.org> # 3.11+
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

1. Propagate ENOTTY  to user space if the client is not present
in the system
2. Use ETIME consistently on timeouts
3. Return EIO on write failures
4. Return ENODEV on recoverable device failures such as resets
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since txe use doorbell and not circular buffer
we have to cheat in write slot counting, txe always consume all the
slots upon write. In order for it to work we need to track
slots using mei_hbuf_empty_slots() instead of tracking it in mei layer
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A client has to acquire host buffer
before writing, we add lock like wrapper
to replace the code snippet

if (dev->hbuf_is_ready)
        dev->hbuf_is_ready = false;
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In mei_cl_read_start(), if it fails to send flow control request, it
will release "cl->read_cb" but forget to set pointer to NULL, leaving
"cl->read_cb" still pointing to random memory, next time this client is
operated like mei_release(), it has chance to refer to this wrong pointer.

Fixes:  PANIC at kfree in mei_release()

[228781.826904] Call Trace:
[228781.829737]  [<c16249b8>] ? mei_cl_unlink+0x48/0xa0
[228781.835283]  [<c1624487>] mei_io_cb_free+0x17/0x30
[228781.840733]  [<c16265d8>] mei_release+0xa8/0x180
[228781.845989]  [<c135c610>] ? __fsnotify_parent+0xa0/0xf0
[228781.851925]  [<c1325a69>] __fput+0xd9/0x200
[228781.856696]  [<c1325b9d>] ____fput+0xd/0x10
[228781.861467]  [<c125cae1>] task_work_run+0x81/0xb0
[228781.866821]  [<c1242e53>] do_exit+0x283/0xa00
[228781.871786]  [<c1a82b36>] ? kprobe_flush_task+0x66/0xc0
[228781.877722]  [<c124eeb8>] ? __dequeue_signal+0x18/0x1a0
[228781.883657]  [<c124f072>] ? dequeue_signal+0x32/0x190
[228781.889397]  [<c1243744>] do_group_exit+0x34/0xa0
[228781.894750]  [<c12517b6>] get_signal_to_deliver+0x206/0x610
[228781.901075]  [<c12018d8>] do_signal+0x38/0x100
[228781.906136]  [<c1626d1c>] ? mei_read+0x42c/0x4e0
[228781.911393]  [<c12600a0>] ? wake_up_bit+0x30/0x30
[228781.916745]  [<c16268f0>] ? mei_poll+0x120/0x120
[228781.922001]  [<c1324be9>] ? vfs_read+0x89/0x160
[228781.927158]  [<c16268f0>] ? mei_poll+0x120/0x120
[228781.932414]  [<c133ca34>] ? fget_light+0x44/0xe0
[228781.937670]  [<c1324e58>] ? SyS_read+0x68/0x80
[228781.942730]  [<c12019f5>] do_notify_resume+0x55/0x70
[228781.948376]  [<c1a7de5d>] work_notifysig+0x29/0x30
[228781.953827]  [<c1a70000>] ? bad_area+0x5/0x3e

Cc: stable <stable@vger.kernel.org> # 3.9+
Signed-off-by: NChao Bi <chao.bi@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We can use simply list_for_each_entry if there is no
entry removal
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We already have a helper to find me client by id, let's
use it in all relevant places.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Drop not-very-useful check and with this
fix read on index that can be after array end.
Cleanup search function as byproduct.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

1. Return -ENOTTY on client connect if the requested client was not found
 on the enumeration list or the client was internally disabled, in the later
 case FW will return NOT_FOUND.
2. Return -EBUSY if the client cannot be connected because of resource
 contention
3. Change response status enum to have MEI_CL_ prefix
4. Add function to translate response status to a string
for more readable logging
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This operation actually only support connection
and not a generic ioctl
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Don't set read callback to NULL during reset as
this leads to memory leak of both cb and its buffer.
The memory is correctly freed during mei_release.

The memory leak is detectable by kmemleak if
application has open read call while system is going through
suspend/resume.

unreferenced object 0xecead780 (size 64):
  comm "AsyncTask #1", pid 1018, jiffies 4294949621 (age 152.440s)
  hex dump (first 32 bytes):
    00 01 10 00 00 02 20 00 00 bf 30 f1 00 00 00 00  ...... ...0.....
    00 00 00 00 00 00 00 00 36 01 00 00 00 70 da e2  ........6....p..
  backtrace:
    [<c1a60aec>] kmemleak_alloc+0x3c/0xa0
    [<c131ed56>] kmem_cache_alloc_trace+0xc6/0x190
    [<c16243c9>] mei_io_cb_init+0x29/0x50
    [<c1625722>] mei_cl_read_start+0x102/0x360
    [<c16268f3>] mei_read+0x103/0x4e0
    [<c1324b09>] vfs_read+0x89/0x160
    [<c1324d5f>] SyS_read+0x4f/0x80
    [<c1a7b318>] syscall_call+0x7/0xb
    [<ffffffff>] 0xffffffff
unreferenced object 0xe2da7000 (size 512):
  comm "AsyncTask #1", pid 1018, jiffies 4294949621 (age 152.440s)
  hex dump (first 32 bytes):
    00 6c da e2 7c 00 00 00 00 00 00 00 c0 eb 0c 59  .l..|..........Y
    1b 00 00 00 01 00 00 00 02 10 00 00 01 00 00 00  ................
  backtrace:
    [<c1a60aec>] kmemleak_alloc+0x3c/0xa0
    [<c131f127>] __kmalloc+0xe7/0x1d0
    [<c162447e>] mei_io_cb_alloc_resp_buf+0x2e/0x60
    [<c162574c>] mei_cl_read_start+0x12c/0x360
    [<c16268f3>] mei_read+0x103/0x4e0
    [<c1324b09>] vfs_read+0x89/0x160
    [<c1324d5f>] SyS_read+0x4f/0x80
    [<c1a7b318>] syscall_call+0x7/0xb
    [<ffffffff>] 0xffffffff
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Clear write callbacks sitting in write_waiting list on reset.
Otherwise these callbacks are left dangling and cause memory leak.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

give up reseting after 3 unsuccessful tries
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix syntax errors in comments and debug strings
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Set hbm header bit 30 for internal commands
This mark commands that are generated by
the device driver
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

list_del_init appears twice in row in mei_cl_unlink, drop one.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Move host_clients_map cleanup from host client init to device init.

This fixes bug where we cleaned up the bitmask that servers as pool for
host client ids while file descriptors are kept open during suspend.
On resume a new connection will be assigned id that is already taken
by opened file descriptor. Consequently read/write will fail due to
mismatched book keeping.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make open counter to be incremented and decremented
from mei_cl_link and mei_cl_unlik function respectively

Nfc was assuming symmetric linking API and thus open handler
count was never decreased. This patch fixes that.
We need to add separate open hander count for amthif which
is handled out of link/unlink functions and doesn't break
the symmetric API.

Last we do not waste clients slots if amthif or wd are not present
in the device. we don't need to allocates slots ahead
it is all covered by link/unlink before the devices is responding
to user space connection and thus not racing on allocation
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

1. Perform simple checks first and only then attempt to allocate cl structure.
2. Remove open_handler_count test, this is already checked in mei_cl_link function
3. return -EMFILE instead of -ENOENT as expected by user space
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

we can call list_del_init regardless the client is
linked or not it is always properly initialized
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

this eventually allows as use a single write queue
both for control and data messages and removing possible
race
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

ENODEV will cause application to try to reconnect since
it assumes that device went through the reset
write errors are not always fatal it can happen due to
resource contention
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

define cl_dbg and cl_err macros that add me and host id
prefix for debug and error log messages so we can track
for the client context of the flow.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

mei_cl_link is called both from mei_open and also from
in-kernel drivers so we need to protect open_handle_count
from overflow
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Clear pending connection after hw reset but before hw start
and wake up the waiting task in poll. Signal POLLERR in select
when device went through reset.

Add wrapper mei_cl_is_connected for checking if
the device and client are connected.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

wake writers otherwise might have processes waiting
endlessly on wait_tx during reset
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

MEI_CL_CONNECT_TIMEOUT is the timeout in seconds to wait
for a response in mei_cl_connect.
The value was converted to jiffies using mei_secs_to_jiffies
helper function and assigned to a local variable
which is by mistake again multiplied by HZ
Signed-off-by: NFrode Isaksen <frodex.isaksen@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

when we buffer write request we should not switch to
MEI_WRITING since this will override MEI_WRITE_COMPLETE
state of preceding write
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

mei_cl_irq_write_complete operates on a client so move it
to client.c
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

1. rename mei_cl_complete_handler to mei_cl_complete
2. move the function client.c where it belongs
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

While writting to device is limitted to max_msg_length advertized
in client properites the read can be much longer delivered consequiting chunks.

We use krealloc to enlarge the buffer when needed.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

NFC ME device is exported through the MEI bus to be consumed by the
NFC subsystem.

NFC is represented by two mei clients: An info one and the actual
NFC one. In order to properly build the ME id we first need to retrieve
the firmware information from the info client and then disconnect from it.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

consolidate write code to a specific me client in mei_cl_write function
the function is called from mei device write handler and from
mei_cl bus send function
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Correct typos and fix stray comments.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Acked-by: NWinkler, Tomas <tomas.winkler@intel.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

We keep track of all MEI devices on the bus through a specific linked list.
We also have a mei_device instance in the mei_cl structure.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

during reset we clean up client data structures
we move that code into wrappers in client
and call the wrappers
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>