Commit Graph

616432 Commits

Author SHA1 Message Date
Sudeep Holla 46a3d5cdb0 coresight: etm4x: request to retain power to the trace unit when active
The Coresight ETMv4 architecture provides a way to request to keep the
power to the trace unit. This might help to collect the traces without
the need to disable the CPU power management(entering/exiting deeper
idle states).

Trace PowerDown Control Register provides powerup request bit which when
set requests the system to retain power to the trace unit and emulate
the powerdown request.

Typically, a trace unit drives a signal to the power controller to
request that the trace unit core power domain is powered up. However,
if the trace unit and the CPU are in the same power domain then the
implementation might combine the trace unit power up status with a
signal from the CPU.

This patch requests to retain power to the trace unit when active and
to remove when inactive. Note this change will only request but the
behaviour depends on the implementation. However, it matches the
exact behaviour expected when the external debugger is connected with
respect to CPU power states.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Markus Elfring 1d37ae5067 coresight: tmc: Delete an unnecessary check before the function call "kfree"
The kfree() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Wei Yongjun 57a3668beb coresight: etm4x: remove duplicated include from coresight-etm4x.c
Remove duplicated include.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Suzuki K Poulose 9486295ad1 coresight: Use local coresight_desc instances
Each coresight device prepares a description for coresight_register()
in struct coresight_desc. Once we register the device, the description is
useless and can be freed. The coresight_desc is small enough (48bytes on
64bit)i to be allocated on the stack. Hence use an automatic variable to
avoid a needless dynamic allocation and wasting the memory(which will only
be free'd when the device is destroyed).

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Peter Chen 7f73b0b9fa hwtracing: coresight: of_coresight: add missing of_node_put after calling of_parse_phandle
of_node_put needs to be called when the device node which is got
from of_parse_phandle has finished using.

Cc: linux-arm-kernel@lists.infradead.org
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Olivier Schonken 2a18d7267a coresight-etm3x: Add ARM ETM 3.5 Cortex-A5 peripheral ID
Signed-off-by: Olivier Schonken <olivier.schonken@gmail.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Mathieu Poirier cd9e3474bb coresight: add PM runtime calls to coresight_simple_func()
It is mandatory to enable a coresight block's power domain before
trying to access management registers.  Otherwise the transaction
simply stalls, leading to a system hang.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Mathieu Poirier 62d39ac934 coresight: delay initialisation when children are missing
Depending on when CoreSight device are discovered it is possible
that some IP block may be referencing devices that have not been
added to the bus yet.  The end result is missing nodes in the
CoreSight topology even when the devices are present and properly
initialised.

This patch solves the problem by asking the driver core to
try initialising the device at a later time when the children
of a CoreSight node are missing.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 67337e8d8d coresight: Add better messages for coresight_timeout
When we encounter a timeout waiting for a status change via
coresight_timeout, the caller always print the offset which
was tried. This is pretty much useless as it doesn't specify
the bit position we wait for. Also, one needs to lookup the
TRM to figure out, what was wrong. This patch changes all
such error messages to print something more meaningful.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 1c9cbe1184 coresight: Cleanup TMC status check
Use the defined symbol rather than hardcoding the value to
check whether the TMC buffer is full.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 78247e25e8 coresight: etmv4: Fix ETMv4x peripheral ID table
This patch cleans up the peripheral id table for different ETMv4
implementations.

As per Cortex-A53 TRM, the ETM has following id values:

Peripheral ID0	0x5D	0xFE0
Peripheral ID1	0xB9	0xFE4
Peripheral ID2	0x4B	0xFE8
Peripheral ID3	0x00	0xFEC

where, PID2: has the following format:

[7:4]   Revision
[3]     JEDEC   0b1     res1. Indicates a JEP106 identity code is used
[2:0]   DES_1   0b011   ARM Limited. This is bits[6:4] of JEP106 ID code

The existing table entry checks only the bits [1:0], which is not
sufficient enough. Fix it to match bits [3:0], just like the other
entries do. While at it, correct the comment for A57 and the A53 entry.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 8505feaed9 coresight: tmc: Limit the trace to available data
At present the ETF or ETR gives out the entire device
buffer, even if there is less or even no trace data
available. This patch limits the trace data given out to
the actual trace data collected.

Cc: mathieu.poirier@linaro.org
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 068c0a542f coresight: Fix csdev connections initialisation
This is a cleanup patch.

coresight_device->conns holds an array to point to the devices
connected to the OUT ports of a component. Sinks, e.g ETR, do not
have an OUT port (nr_outport = 0), as it streams the trace to
memory via AXI.

At coresight_register() we do :

	conns = kcalloc(csdev->nr_outport, sizeof(*conns), GFP_KERNEL);
	if (!conns) {
		ret = -ENOMEM;
		goto err_kzalloc_conns;
	}

For ETR, since the total size requested for kcalloc is zero, the return
value is, ZERO_SIZE_PTR ( != NULL). Hence, csdev->conns = ZERO_SIZE_PTR
which cannot be verified later to contain a valid pointer. The code which
accesses the csdev->conns is bounded by the csdev->nr_outport check,
hence we don't try to dereference the ZERO_SIZE_PTR. This patch cleans
up the csdev->conns initialisation to make sure we initialise it
properly(i.e, either NULL or valid conns array).

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 3afd0634a2 coresight: Consolidate error handling path for tmc_probe
This patch cleans up the error handling path for tmc_probe
as a side effect of the removal of the spurious dma_free_coherent().

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 481e46fe7a coresight: Remove erroneous dma_free_coherent in tmc_probe
commit de5461970b ("coresight: tmc: allocating memory when needed")
removed the static allocation of buffer for the trace data in ETR mode in
tmc_probe. However it failed to remove the "devm_free_coherent" in
tmc_probe when the probe fails due to other reasons. This patch gets
rid of the incorrect dma_free_coherent() call.

Fixes: commit de5461970b ("coresight: tmc: allocating memory when needed")
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Sudeep Holla b1149ad917 coresight: always use stashed trace id value in etm4_trace_id
etm4_trace_id is not guaranteed to be executed on the CPU whose ETM is
being accessed. This leads to exception similar to below one if the
CPU whose ETM is being accessed is in deeper idle states. So it must
be executed on the CPU whose ETM is being accessed.

Unhandled fault: synchronous external abort (0x96000210) at 0xffff000008db4040
Internal error: : 96000210 [#1] PREEMPT SMP
Modules linked in:
CPU: 5 PID: 5979 Comm: etm.sh Not tainted 4.7.0-rc3 #159
Hardware name: ARM Juno development board (r2) (DT)
task: ffff80096dd34b00 ti: ffff80096dfe4000 task.ti: ffff80096dfe4000
PC is at etm4_trace_id+0x5c/0x90
LR is at etm4_trace_id+0x3c/0x90
Call trace:
 etm4_trace_id+0x5c/0x90
 coresight_id_match+0x78/0xa8
 bus_for_each_dev+0x60/0xa0
 coresight_enable+0xc0/0x1b8
 enable_source_store+0x3c/0x70
 dev_attr_store+0x18/0x28
 sysfs_kf_write+0x48/0x58
 kernfs_fop_write+0x14c/0x1e0
 __vfs_write+0x1c/0x100
 vfs_write+0xa0/0x1b8
 SyS_write+0x44/0xa0
 el0_svc_naked+0x24/0x28

However, TRCTRACEIDR is not guaranteed to hold the previous programmed
trace id if it enters deeper idle states. Further, the trace id that is
computed in etm4_init_trace_id is programmed into TRCTRACEIDR only in
etm4_enable_hw which happens much later in the sequence after
coresight_id_match is executed from enable_source_store.

This patch simplifies etm4_trace_id by returning the stashed trace id
value similar to etm4_cpu_id.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Chunyan Zhang f3864d8562 coresight-stm: support mmapping channel regions with mmio_addr
CoreSight STM device allows direct mapping of the channel regions to
userspace for zero-copy writing. To support this ability, the STM
framework has provided a hook 'mmio_addr', this patch just implemented
this hook for CoreSight STM.

This patch also added an item into 'channel_space' to save the physical
base address of channel region which mmap operation needs to know.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Sudeep Holla b839215372 coresight: access conn->child_name only if it's initialised
If the addition of the coresight devices get deferred, then there's a
window before child_name is populated by of_get_coresight_platform_data
from the respective component driver's probe and the attempted to access
the same from coresight_orphan_match resulting in kernel NULL pointer
dereference as below:

Unable to handle kernel NULL pointer dereference at virtual address 0x0
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1038 Comm: kworker/0:1 Not tainted 4.7.0-rc3 #124
Hardware name: ARM Juno development board (r2) (DT)
Workqueue: events amba_deferred_retry_func
PC is at strcmp+0x1c/0x160
LR is at coresight_orphan_match+0x7c/0xd0
Call trace:
 strcmp+0x1c/0x160
 bus_for_each_dev+0x60/0xa0
 coresight_register+0x264/0x2e0
 tmc_probe+0x130/0x310
 amba_probe+0xd4/0x1c8
 driver_probe_device+0x22c/0x418
 __device_attach_driver+0xbc/0x158
 bus_for_each_drv+0x58/0x98
 __device_attach+0xc4/0x160
 device_initial_probe+0x10/0x18
 bus_probe_device+0x94/0xa0
 device_add+0x344/0x580
 amba_device_try_add+0x194/0x238
 amba_deferred_retry_func+0x48/0xd0
 process_one_work+0x118/0x378
 worker_thread+0x48/0x498
 kthread+0xd0/0xe8
 ret_from_fork+0x10/0x40

This patch adds a check for non-NULL conn->child_name before accessing
the same.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Alex Ng b605c2d913 Drivers: hv: balloon: Use available memory value in pressure report
Reports for available memory should use the si_mem_available() value.
The previous freeram value does not include available page cache memory.

Signed-off-by: Alex Ng <alexng@messages.microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Vitaly Kuznetsov eece30b9f0 Drivers: hv: balloon: replace ha_region_mutex with spinlock
lockdep reports possible circular locking dependency when udev is used
for memory onlining:

 systemd-udevd/3996 is trying to acquire lock:
  ((memory_chain).rwsem){++++.+}, at: [<ffffffff810d137e>] __blocking_notifier_call_chain+0x4e/0xc0

 but task is already holding lock:
  (&dm_device.ha_region_mutex){+.+.+.}, at: [<ffffffffa015382e>] hv_memory_notifier+0x5e/0xc0 [hv_balloon]
 ...

which is probably a false positive because we take and release
ha_region_mutex from memory notifier chain depending on the arg. No real
deadlocks were reported so far (though I'm not really sure about
preemptible kernels...) but we don't really need to hold the mutex
for so long. We use it to protect ha_region_list (and its members) and the
num_pages_onlined counter. None of these operations require us to sleep
and nothing is slow, switch to using spinlock with interrupts disabled.

While on it, replace list_for_each -> list_for_each_entry as we actually
need entries in all these cases, drop meaningless list_empty() checks.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov a132c54cbc Drivers: hv: balloon: don't wait for ol_waitevent when memhp_auto_online is enabled
With the recently introduced in-kernel memory onlining
(MEMORY_HOTPLUG_DEFAULT_ONLINE) these is no point in waiting for pages
to come online in the driver and we can get rid of the waiting.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov cb7a5724c7 Drivers: hv: balloon: account for gaps in hot add regions
I'm observing the following hot add requests from the WS2012 host:

hot_add_req: start_pfn = 0x108200 count = 330752
hot_add_req: start_pfn = 0x158e00 count = 193536
hot_add_req: start_pfn = 0x188400 count = 239616

As the host doesn't specify hot add regions we're trying to create
128Mb-aligned region covering the first request, we create the 0x108000 -
0x160000 region and we add 0x108000 - 0x158e00 memory. The second request
passes the pfn_covered() check, we enlarge the region to 0x108000 -
0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the
third request as it starts at 0x188400 so there is a 0x200 gap which is
not covered. As the end of our region is 0x190000 now it again passes the
pfn_covered() check were we just adjust the covered_end_pfn and make it
0x188400 instead of 0x188200 which means that we'll try to online
0x188200-0x188400 pages but these pages were never assigned to us and we
crash.

We can't react to such requests by creating new hot add regions as it may
happen that the whole suggested range falls into the previously identified
128Mb-aligned area so we'll end up adding nothing or create intersecting
regions and our current logic doesn't allow that. Instead, create a list of
such 'gaps' and check for them in the page online callback.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov 7cf3b79ec8 Drivers: hv: balloon: keep track of where ha_region starts
Windows 2012 (non-R2) does not specify hot add region in hot add requests
and the logic in hot_add_req() is trying to find a 128Mb-aligned region
covering the request. It may also happen that host's requests are not 128Mb
aligned and the created ha_region will start before the first specified
PFN. We can't online these non-present pages but we don't remember the real
start of the region.

This is a regression introduced by the commit 5abbbb75d7 ("Drivers: hv:
hv_balloon: don't lose memory when onlining order is not natural"). While
the idea of keeping the 'moving window' was wrong (as there is no guarantee
that hot add requests come ordered) we should still keep track of
covered_start_pfn. This is not a revert, the logic is different.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov 26840437cb Tools: hv: kvp: ensure kvp device fd is closed on exec
KVP daemon does fork()/exec() (with popen()) so we need to close our fds
to avoid sharing them with child processes. The immediate implication of
not doing so I see is SELinux complaining about 'ip' trying to access
'/dev/vmbus/hv_kvp'.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
K. Y. Srinivasan 3724287c0e Drivers: hv: vmbus: Implement a mechanism to tag the channel for low latency
On Hyper-V, performance critical channels use the monitor
mechanism to signal the host when the guest posts mesages
for the host. This mechanism minimizes the hypervisor intercepts
and also makes the host more efficient in that each time the
host is woken up, it processes a batch of messages as opposed to
just one. The goal here is improve the throughput and this is at
the expense of increased latency.
Implement a mechanism to let the client driver decide if latency
is important.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
K. Y. Srinivasan 8de0d7e951 Drivers: hv: vmbus: Reduce the delay between retries in vmbus_post_msg()
The current delay between retries is unnecessarily high and is negatively
affecting the time it takes to boot the system.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
K. Y. Srinivasan ccef9bcc02 Drivers: hv: vmbus: Enable explicit signaling policy for NIC channels
For synthetic NIC channels, enable explicit signaling policy as netvsc wants to
explicitly control when the host is to be signaled.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Dexuan Cui 638fea33ae Drivers: hv: vmbus: fix the race when querying & updating the percpu list
There is a rare race when we remove an entry from the global list
hv_context.percpu_list[cpu] in hv_process_channel_removal() ->
percpu_channel_deq() -> list_del(): at this time, if vmbus_on_event() ->
process_chn_event() -> pcpu_relid2channel() is trying to query the list,
we can get the kernel fault.

Similarly, we also have the issue in the code path: vmbus_process_offer() ->
percpu_channel_enq().

We can resolve the issue by disabling the tasklet when updating the list.

The patch also moves vmbus_release_relid() to a later place where
the channel has been removed from the per-cpu and the global lists.

Reported-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov e0fa3e5e7d Drivers: hv: utils: fix a race on userspace daemons registration
Background: userspace daemons registration protocol for Hyper-V utilities
drivers has two steps:
1) daemon writes its own version to kernel
2) kernel reads it and replies with module version
at this point we consider the handshake procedure being completed and we
do hv_poll_channel() transitioning the utility device to HVUTIL_READY
state. At this point we're ready to handle messages from kernel.

When hvutil_transport is in HVUTIL_TRANSPORT_CHARDEV mode we have a
single buffer for outgoing message. hvutil_transport_send() puts to this
buffer and till the buffer is cleared with hvt_op_read() returns -EFAULT
to all consequent calls. Host<->guest protocol guarantees there is no more
than one request at a time and we will not get new requests till we reply
to the previous one so this single message buffer is enough.

Now to the race. When we finish negotiation procedure and send kernel
module version to userspace with hvutil_transport_send() it goes into the
above mentioned buffer and if the daemon is slow enough to read it from
there we can get a collision when a request from the host comes, we won't
be able to put anything to the buffer so the request will be lost. To
solve the issue we need to know when the negotiation is really done (when
the version message is read by the daemon) and transition to HVUTIL_READY
state after this happens. Implement a callback on read to support this.
Old style netlink communication is not affected by the change, we don't
really know when these messages are delivered but we don't have a single
message buffer there.

Reported-by: Barry Davis <barry_davis@stormagic.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov 396e287fa2 Drivers: hv: get rid of timeout in vmbus_open()
vmbus_teardown_gpadl() can result in infinite wait when it is called on 5
second timeout in vmbus_open(). The issue is caused by the fact that gpadl
teardown operation won't ever succeed for an opened channel and the timeout
isn't always enough. As a guest, we can always trust the host to respond to
our request (and there is nothing we can do if it doesn't).

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov 7cc80c9807 Drivers: hv: don't leak memory in vmbus_establish_gpadl()
In some cases create_gpadl_header() allocates submessages but we never
free them.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov 4d63763296 Drivers: hv: get rid of redundant messagecount in create_gpadl_header()
We use messagecount only once in vmbus_establish_gpadl() to check if
it is safe to iterate through the submsglist. We can just initialize
the list header in all cases in create_gpadl_header() instead.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:40 +02:00
Vitaly Kuznetsov a9f61ca793 Drivers: hv: avoid vfree() on crash
When we crash from NMI context (e.g. after NMI injection from host when
'sysctl -w kernel.unknown_nmi_panic=1' is set) we hit

    kernel BUG at mm/vmalloc.c:1530!

as vfree() is denied. While the issue could be solved with in_nmi() check
instead I opted for skipping vfree on all sorts of crashes to reduce the
amount of work which can cause consequent crashes. We don't really need to
free anything on crash.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:40 +02:00
Chris Metcalf 069b188f43 tile-srom: avoid krealloc(... __GFP_ZERO) pattern
Joe Perches points out [1] that this pattern isn't currently safe.
This driver doesn't really need the zeroing semantic anyway;
by restructuring the code slightly we can initialize all the
fields of the structure up front instead.

[1] https://lkml.kernel.org/r/1469729491.3998.58.camel@perches.com

Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:45:50 +02:00
Muhammad Falak R Wani acde785e49 misc: mic: scif: use vma_pages().
Replace explicit computation of vma page count by a call to
vma_pages()

Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:45:50 +02:00
Alexandre Belloni b6faae97a1 Documentation: mic: fix kernel version
v3.20 doesn't exist. heartbeat_enable was actually added in v4.4.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:45:50 +02:00
Arnd Bergmann 9d32f82e04 mic: remove unused function arg
When building with W=1, the __scif_rma_destroy_tcw function
causes a harmless warning about an argument variable that is
modified but not used:

drivers/misc/mic/scif/scif_dma.c: In function ‘__scif_rma_destroy_tcw’:
drivers/misc/mic/scif/scif_dma.c:118:27: error: parameter ‘ep’ set but not used [-Werror=unused-but-set-parameter]

In this case, we can just remove the argument, since all callers
are in the same file.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:45:50 +02:00
Alexander Usyskin e728ae271f mei: amthif: fix deadlock in initialization during a reset
The device lock was unnecessary obtained in bus rescan work before the
amthif client search.  That causes incorrect lock ordering and task
hang:
...
[88004.613213] INFO: task kworker/1:14:21832 blocked for more than 120 seconds.
...
[88004.645934] Workqueue: events mei_cl_bus_rescan_work
...

The correct lock order is
 cl_bus_lock
  device_lock
   me_clients_rwsem

Move device_lock into amthif init function that called
after me_clients_rwsem is released.

This fixes regression introduced by commit:
commit 025fb792ba ("mei: split amthif client init from end of clients enumeration")

Cc: <stable@vger.kernel.org> # 4.6+
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:39:43 +02:00
Alexander Usyskin 80293c47a6 mei: drop unused file transaction states
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:39:42 +02:00
Alexander Usyskin 9d27e73c18 mei: amthif: drop mei_amthif_read
mei_amthif_read have only one difference from mei_read, it is not
calling mei_read_start().
Make mei_read_start return immediately for amthif client and drop the
special mei_amthif_read function.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:39:42 +02:00
Alexander Usyskin ff1586a7ea mei: enqueue consecutive reads
The FW supports only one pending read per host client, in order to
support  issuing of consecutive reads the driver  queues read requests
internally and send them to the firmware after pending one has
completed.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:39:42 +02:00
Tomas Winkler 3030dc0564 mei: add wrapper for queuing control commands.
Enclose the boiler plate code of allocating a control/hbm command cb
and enqueueing it onto ctrl_wr.list in a convenient wrapper
mei_cl_enqueue_ctrl_wr_cb().

This is a preparatory patch for enabling consecutive reads.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:39:42 +02:00
Tomas Winkler 4034b81ba3 mei: use consistent naming for TX control flow credits
With the introduction of the receive control flow credits prefixed with
rx_ we add tx_ prefix to the variables and function used for tracking
the transmit control flow credits.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:39:42 +02:00
Alexander Usyskin 46978ada7d mei: rx flow control counter
Use RX flow control counter in the host client structure to
track the number of simultaneous outstanding reads.
This eliminates search in queues and makes ground for
enabling for parallel read.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:39:42 +02:00
Alexander Usyskin e51dfa5a7f mei: prepare read cb for fixed address clients on the receive path only.
The read callbacks for the fixed address clients, that don't have flow
control are built now on the receive path. In order to have a single
allocation place we remove the allocation from the read request.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:39:42 +02:00
Alexander Usyskin dfe5f753d0 mei: drop redundant krealloc and checks in irq read
The read callback is always prepared with MTU-sized buffer and the FW
can't send more than the MTU in one message.
Checking for buffer existence and krealloc to increase receive buffer
size are redundant and may be safely discarded.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:39:42 +02:00
Alexander Usyskin c85dba9e87 mei: amthif: drop mei_clear_lists function
Open code mei_clear_lists into its only caller mei_amthif_releas
and drop unused parameter 'dev' form from mei_clear_list function.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:36:40 +02:00
Alexander Usyskin a808c80cda mei: add read callback on demand for fixed_address clients
The Fixed address clients do not work with the flow control, and the
packet RX callback was allocated upon TX with anticipation of a
following RX. This won't work if the clients with unsolicited Rx. Rather
than preparing read callback upon a write we allocate one directly on
the reciev path if one doesn't exists.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:36:39 +02:00
Alexander Usyskin 97d549b4d5 mei: add file pointer to the host client structure
Store the file associated with a client in the host client structure,
this enables dropping the special amthif client file pointer from struct
mei_device, and this is also a preparation for changing the way rx
packet allocation for fixed_address clients

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:36:39 +02:00
Alexander Usyskin a03c608f25 mei: move read cb to complete queue if not connected
Move read cb to the completion queue if a read finds out that client
is not connected. This expedite user space reader wake on error
condition.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30 14:36:39 +02:00