Currently we're creating a new cell structure everytime a DT user
calls nvmem_cell_get().
Change this behavior by resolving the cells during nvmem provider
registration and adding all cells to the provider's list. Make
of_nvmem_cell_get() just parse the phandle and look the cell up
in the relevant provider's list.
Add new structs and routines allowing users to define nvmem cells from
machine code. This global list of entries is parsed when a provider
is registered and cells are associated with the relevant nvmem_device
struct.
A possible improvement for the future is to allow users to register
cell tables after the nvmem provider has been registered by updating
the cell list at each call to nvmem_(add|del)_cell_table().
Nvmem subsystem keeps a global list of cells that, for non-DT systems,
can only be referenced by cell name, which makes it impossible to have
more than one nvmem device with cells named the same.
This patch makes every nvmem device the owner of the list of its cells.
This effectively removes the support for non-DT systems, but it will
be reintroduced following a different approach in subsequent patches.
This isn't a problem as support for board files in nvmem is currently
broken anyway: any user that would try to get an nvmem cell from the
global cell list would remove the cell after the calling
nvmem_cell_put(). This can cause anything from a subsequent user not
being able to get the cell to double free errors if more users hold
reference to the same cell at the same time.
Fortunately there are no such users which allows us to rework this part.
We switched the nvmem framework to using kref instead of manually
checking the current number of users in nvmem_unregister() so this
function can no longer fail. We also converted all remaining users
that still checked the return value of nvmem_unregister() to using
devm_nvmem_register(). Make the routine return void.
Use kref for reference counting. Use an approach similar to the one
seen in the common clock subsystem: don't actually destroy the nvmem
device until the last user puts it. This way we can get rid of the
users check from nvmem_unregister().
uio_hv_generic: defer opening vmbus until first use
This fixes two design flaws in hv_uio_generic.
Since hv_uio_probe is called from vmbus_probe with lock held
it potentially can cause sleep in an atomic section because
vmbus_open will wait for response from host.
The hv_uio_generic driver could not handle applications
exiting and restarting because the vmbus channel was
persistent. Change the semantics so that the buffers are
allocated on probe, but not attached to host until
device is opened.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce the concept of mapping physical memory locations that
are normal memory. The new type UIO_MEM_IOVA are similar to
existing UIO_MEM_PHYS but the backing memory is not marked as uncached.
Also, indent related switch to the currently used style.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The UIO driver needs the ring buffer to be persistent(reused)
across open/close. Split the allocation and setup of ring buffer
out of vmbus_open. For normal usage vmbus_open/vmbus_close there
are no changes; only impacts uio_hv_generic which needs to keep
ring buffer memory and reuse when application restarts.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Roman Kiryanov [Fri, 14 Sep 2018 17:51:03 +0000 (10:51 -0700)]
platform: goldfish: pipe: Prevent memory corruption from several threads writing to the same variable
Move the "pages" buffer into "struct goldfish_pipe". Since we are
locking the mutex on the pipe in transfer_max_buffers, other threads
willnot be able to write into it, but other pipe instances could be
served because they have its own buffer.
Signed-off-by: Roman Kiryanov <rkir@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The function should return -EFAULT when copy_from_user fails. Even
though the caller does not distinguish them. but we should keep backward
compatibility.
Clang warns when a variable is assigned to itself.
drivers/misc/mic/scif/scif_dma.c:1577:12: warning: explicitly assigning
value of variable of type 'bool' (aka '_Bool') to itself [-Wself-assign]
dst_local = dst_local;
~~~~~~~~~ ^ ~~~~~~~~~
1 warning generated.
This is usually done to avoid an unused variable warning, which is the
case here. dst_local is used nowhere in this function, which has been
the case since the initial code drop in commit 7cc31cd27752 ("misc: mic:
SCIF DMA and CPU copy interface") in 2015. Just remove the variable, it
can be added back if it was intended to be used.
Laura Abbott [Tue, 11 Sep 2018 17:44:03 +0000 (10:44 -0700)]
misc: kgdbts: Fix restrict error
kgdbts current fails when compiled with restrict:
drivers/misc/kgdbts.c: In function ‘configure_kgdbts’:
drivers/misc/kgdbts.c:1070:2: error: ‘strcpy’ source argument is the same as destination [-Werror=restrict]
strcpy(config, opt);
^~~~~~~~~~~~~~~~~~~
As the error says, config is being used in both the source and destination.
Refactor the code to avoid the extra copy and put the parsing closer to
the actual location.
Signed-off-by: Laura Abbott <labbott@redhat.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
misc: echo: Remove unnecessary parentheses and simplify check for zero
Clang warns when multiple pairs of parentheses are used for a single
conditional statement.
drivers/misc/echo/echo.c:384:27: warning: equality comparison with
extraneous parentheses [-Wparentheses-equality]
if ((ec->nonupdate_dwell == 0)) {
~~~~~~~~~~~~~~~~~~~~^~~~
drivers/misc/echo/echo.c:384:27: note: remove extraneous parentheses
around the comparison to silence this warning
if ((ec->nonupdate_dwell == 0)) {
~ ^ ~
drivers/misc/echo/echo.c:384:27: note: use '=' to turn this equality
comparison into an assignment
if ((ec->nonupdate_dwell == 0)) {
^~
=
1 warning generated.
Remove them and while we're at it, simplify the zero check as '!var' is
used more than 'var == 0'.
Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
device status update can be racy with probe in some cases, so make sure
it take lock during the probe. Also after probe the device is expected
to be ready for communications, so make sure that a logical address
can be assigned to it after probe. If it fails to do so then probe
defer such instances.
Register slimbus controller only after finishing powerup sequnce so that we
do not endup in situation where core starts sending transactions before
the controller is ready.
Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nadav Amit [Thu, 20 Sep 2018 17:30:18 +0000 (10:30 -0700)]
vmw_balloon: rework the inflate and deflate loops
In preparation for supporting compaction and OOM notification, this
patch reworks the inflate/deflate loops. The main idea is to separate
the allocation, communication with the hypervisor, and the handling of
errors from each other. Doing will allow us to perform concurrent
inflation and deflation, excluding the actual communication with the
hypervisor.
To do so, we need to get rid of the remaining global state that is kept
in the balloon struct, specifically the refuse_list. When the VM
communicates with the hypervisor, it does not free or put back pages
to the balloon list and instead only moves the pages whose status
indicated failure into a refuse_list on the stack. Once the operation
completes, the inflation or deflation functions handle the list
appropriately.
As we do that, we can consolidate the communication with the hypervisor
for both the lock and unlock operations into a single function. We also
reuse the deflation function for popping the balloon.
As a preparation for preventing races, we hold a spinlock when the
communication actually takes place, and use atomic operations for
updating the balloon size. The balloon page list is still racy and will
be handled in the next patch.
Nadav Amit [Thu, 20 Sep 2018 17:30:17 +0000 (10:30 -0700)]
vmw_balloon: stats rework
To allow the balloon statistics to be updated concurrently, we change
the statistics to be held per core and aggregate it when needed.
To avoid the memory overhead of keeping the statistics per core, and
since it is likely not used by most users, we start updating the
statistics only after the first use. A read-write semaphore is used to
protect the statistics initialization and avoid races. This semaphore is
(and will) be used to protect configuration changes during reset.
While we are at it, address some other issues: change the statistics
update to inline functions instead of define; use ulong for saving the
statistics; and clean the statistics printouts.
Note that this patch changes the format of the outputs. If there are any
automatic tools that use the statistics, they might fail.
Nadav Amit [Thu, 20 Sep 2018 17:30:16 +0000 (10:30 -0700)]
vmw_balloon: simplify vmballoon_send_get_target()
As we want to leave as little as possible on the global balloon
structure, to avoid possible future races, we want to get rid sysinfo.
We can actually get the total_ram directly, and simplify the logic of
vmballoon_send_get_target() a little.
While we are doing that, let's return int and avoid mistakes due to
bool/int conversions.
Nadav Amit [Thu, 20 Sep 2018 17:30:15 +0000 (10:30 -0700)]
vmw_balloon: refactor change size from vmballoon_work
The required change in the balloon size is currently computed in
vmballoon_work(), vmballoon_inflate() and vmballoon_deflate(). Refactor
it to simplify the next patches.
Nadav Amit [Thu, 20 Sep 2018 17:30:14 +0000 (10:30 -0700)]
vmw_balloon: rename VMW_BALLOON_2M_SHIFT to VMW_BALLOON_2M_ORDER
The name of the macro'd VMW_BALLOON_2M_SHIFT is misleading. The value
reflects 2M huge-page order. Unfortunately, we cannot use
HPAGE_PMD_ORDER, since it is not defined when transparent huge-pages are
off, so we need to define our own one.
Rename it to VMW_BALLOON_2M_ORDER. No functional change.
Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nadav Amit [Thu, 20 Sep 2018 17:30:13 +0000 (10:30 -0700)]
vmw_balloon: treat all refused pages equally
Currently, when the hypervisor rejects a page during lock operation, the
VM treats pages differently according to the error-code: in certain
cases the page is immediately freed, and in others it is put on a
rejection list and only freed later.
The behavior does not make too much sense. If the page is freed
immediately it is very likely to be used again in the next batch of
allocations, and be rejected again.
In addition, for support of compaction and OOM notifiers, we wish to
separate the logic that communicates with the hypervisor (as well as
analyzes the status of each page) from the logic that allocates or free
pages.
Treat all errors the same way, queuing the pages on the refuse list.
Move to the next allocation size (4k) when too many pages are refused.
Free the refused pages when moving to the next size to avoid situations
in which too much memory is waiting to be freed on the refused list.
The current abstractions for batch vs single operations seem suboptimal
and complicate the implementation of additional features (OOM,
compaction).
The immediate problem of the current abstractions is that they cause
differences in how operations are handled when batching is on or off.
For example, the refused_alloc counter is not updated when batching is
on. These discrepancies are caused by code redundancies.
Instead, this patch presents three type of operations, according to
whether batching is on or off: (1) add page, (2) communication with the
hypervisor and (3) retrieving the status of a page.
To avoid the overhead of virtual functions, and since we do not expect
additional interfaces for communication with the hypervisor, we use
static keys instead of virtual functions.
Finally, while we are at it, change vmballoon_init_batching() to return
int instead of bool, to be consistent in the return type and avoid
potential coding errors.
Nadav Amit [Thu, 20 Sep 2018 17:30:11 +0000 (10:30 -0700)]
vmw_balloon: remove sleeping allocations
Splitting the allocations between sleeping and non-sleeping made some
sort of sense as long as rate-limiting was enabled. Now that it is
removed, we need to decide - either we want sleeping allocations or not.
Since no other Linux balloon driver (hv, Xen, virtio) uses sleeping
allocations, use the same approach.
We do distinguish, however, between 2MB allocations and 4kB allocations
and prevent reclamation on 2MB. In both cases, we avoid using emergency
low-memory pools, as it may cause undesired effects.
Nadav Amit [Thu, 20 Sep 2018 17:30:08 +0000 (10:30 -0700)]
vmw_balloon: unify commands tracing and stats
Now that we have a single point, unify the tracing and collecting the
statistics for commands and their failure. While it might somewhat
reduce the control over debugging, it cleans the code a lot.
Nadav Amit [Thu, 20 Sep 2018 17:30:07 +0000 (10:30 -0700)]
vmw_balloon: handle commands in a single function.
By inlining the hypercall interface, we can unify several operations
into one central point in the code:
- Updating the target.
- Updating when a reset is needed.
- Update statistics (which will be done later in the patch-set).
- Print debug-messages (although they cannot be enabled as selectively).
While we updated the coresight DT bindings, some of the
new examples were not updated due to the order in which they
were merged. Let us update all the missed out ones to the
new bindings to avoid confusion.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Rob Herring <robh@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Coresight architecture defines CLAIM tags for a device to negotiate
control of the components (external agent vs self-hosted). Each device
has a pair of registers (CLAIMSET & CLAIMCLR) for managing the CLAIM
tags. However, the protocol for the CLAIM tags is IMPLEMENTATION DEFINED.
PSCI has recommendations for the use of the CLAIM tags to negotiate
controls for external agent vs self-hosted use. This patch implements
the recommended protocol by PSCI.
The claim/disclaim operations are performed from the device specific
drivers. The disadvantage is that the calls are sprinkled in each driver,
but this makes the operation much simpler.
When a replicator port is enabled, we block the traffic
on the other port and route all traffic to the new enabled
port. If there are two active trace sessions each targeting
the two different paths from the replicator, the second session
will disable the first session and route all the data to the
second path.
ETR
/
e.g, replicator
\
ETB
If CPU0 is operated in sysfs mode to ETR and CPU1 is operated
in perf mode to ETB, depending on the order in which the
replicator is enabled one device is blocked.
Ideally we need trace-id for the session to make the
right choice. That implies we need a trace-id allocation
logic for the coresight subsystem and use that to route
the traffic. The short term solution is to only manage
the "target port" and leave the other port untouched.
That leaves both the paths unaffected, except that some
unwanted traffic may be pushed to the paths (if the Trace-IDs
are not far enough), which is still fine and can be filtered
out while processing rather than silently blocking the data.
Add support for handling errors in enabling the component.
The ETM is enabled via cross call to owner CPU. Make
necessary changes to report the error back from the cross
call.
Make sure we honor the errors in CATU device and abort the operation.
While at it, delay setting the etr_buf for the session until we are
sure that we are indeed enabling the ETR.
Refactor the tmc-etr enable operation to make it easier to
handle errors in enabling the hardware. We need to make
sure that the buffer is compatible with the ETR. This
patch re-arranges to make the error handling easier, by
deferring the hardware enablement until all the errors
are checked. This also avoids turning the CATU on/off
during a sysfs read session.
coresight: Handle failures in enabling a trace path
coresight_enable_path() enables the components in a trace
path from a given source to a sink, excluding the source.
The operation is performed in the reverse order; the sink
first and then backwards in the list. However, if we encounter
an error in enabling any of the component, we simply disable
all the components in the given path irrespective of whether
we enabled some of the components in the enable iteration.
This could interfere with another trace session if one of the
link devices is turned off (e.g, TMC-ETF). So, we need to
make sure that we only disable those components which were
actually enabled from the iteration.
This patch achieves the same by refactoring the coresight_disable_path
to accept a "node" to start from in the forward order, which can
then be used from the error path of coresight_enable_path().
With this change, we don't issue a disable call back for a component
which didn't get enabled. This change of behavior triggers
a bug in coresight_enable_link(), where we leave the refcount
on the device and will prevent the device from being enabled
forever. So, we also drop the refcount in the coresight_enable_link()
if the operation failed.
Also, with the refactoring, we always start after the first node (which
is the "SOURCE" device) for disabling the entire path. This implies,
we must not find a "SOURCE" in the middle of the path. Hence, added
a WARN_ON() to make sure the paths we get are sane, rather than
simply ignoring them.
Leo Yan [Thu, 20 Sep 2018 19:18:02 +0000 (13:18 -0600)]
coresight: tmc: Fix byte-address alignment for RRP
>From the comment in the code, it claims the requirement for byte-address
alignment for RRP register: 'for 32-bit, 64-bit and 128-bit wide trace
memory, the four LSBs must be 0s. For 256-bit wide trace memory, the
five LSBs must be 0s'. This isn't consistent with the program, the
program sets five LSBs as zeros for 32/64/128-bit wide trace memory and
set six LSBs zeros for 256-bit wide trace memory.
After checking with the CoreSight Trace Memory Controller technical
reference manual (ARM DDI 0461B, section 3.3.4 RAM Read Pointer
Register), it proves the comment is right and the program does wrong
setting.
This patch fixes byte-address alignment for RRP by following correct
definition in the technical reference manual.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Leach <mike.leach@linaro.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Leo Yan [Thu, 20 Sep 2018 19:18:01 +0000 (13:18 -0600)]
coresight: tmc: Refactor loops in etb dump
In ETB dump function tmc_etb_dump_hw() it has nested loops. The second
level loop is to iterate index in the range [0 .. drvdata->memwidth);
but the index isn't really used in the code, thus the second level
loop is useless.
This patch is to remove the second level loop; the refactor also reduces
indentation and we can use 'break' to replace 'goto' tag.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tomasz Nowicki [Thu, 20 Sep 2018 19:18:00 +0000 (13:18 -0600)]
coresight: etm4x: Configure EL2 exception level when kernel is running in HYP
For non-VHE systems host kernel runs at EL1 and jumps to EL2 whenever
hypervisor code should be executed. In this case ETM4x driver must
restrict configuration to EL1 when it setups kernel tracing.
However, there is no separate hypervisor privilege level when VHE
is enabled, the host kernel runs at EL2.
This patch fixes configuration of TRCACATRn register for VHE systems
so that ETM_EXLEVEL_NS_HYP bit is used instead of ETM_EXLEVEL_NS_OS
to on/off kernel tracing. At the same time, it moves common code
to new helper.
Up until now the relative simplicity of enabling the ETB made it
possible to accommodate processing for both sysFS and perf methods.
But work on claimtags and CPU-wide trace scenarios is adding some
complexity, making the current code messy and hard to maintain.
As such follow what has been done for ETF and ETR components and split
function etb_enable() so that processing for both API can be done
cleanly.
This patch moves the etb_drvdata::mode from a locat_t to a simple u32,
as it is for the ETF and ETR drivers. This streamlines the code and adds
commonality with the other drivers when dealing with similar operations.
Add support for using TMC-ETR as backend for ETM perf tracing.
We use software double buffering at the moment. i.e, the TMC-ETR
uses a separate buffer than the perf ring buffer. The data is
copied to the perf ring buffer once a session completes.
The TMC-ETR would try to match the larger of perf ring buffer
or the ETR buffer size configured via sysfs, scaling down to
a minimum limit of 1MB.
In coresight perf mode, we need to prepare the sink before
starting a session, which is done via set_buffer call back.
We then proceed to enable the tracing. If we fail to start
the session successfully, we leave the sink configuration
unchanged. In order to make the operation atomic and to
avoid yet another call back to clear the buffer, we get
rid of the "set_buffer" call back and pass the buffer details
via enable() call back to the sink.
coresight: perf: Add helper to retrieve sink configuration
We can always find the sink configuration for a given perf_output_handle.
Add a helper to retrieve the sink configuration for a given
perf_output_handle. This will be used to get rid of the set_buffer()
call back.
coresight: perf: Remove reset_buffer call back for sinks
Right now we issue an update_buffer() and reset_buffer() call backs
in succession when we stop tracing an event. The update_buffer is
supposed to check the status of the buffer and make sure the ring buffer
is updated with the trace data. And we store information about the
size of the data collected only to be consumed by the reset_buffer
callback which always follows the update_buffer. This was originally
designed for handling future IPs which could trigger a buffer overflow
interrupt. This patch gets rid of the reset_buffer callback altogether
and performs the actions in update_buffer, making it return the size
collected. We can always add the support for handling the overflow
interrupt case later.
This removes some not-so pretty hack (storing the new head in the
size field for snapshot mode) and cleans it up a little bit.
Convert component enable/disable messages from dev_info to dev_dbg.
When used with perf, the components in the paths are enabled/disabled
during each schedule of the run, which can flood the dmesg with these
messages. Moreover, they are only useful for debug purposes. So,
convert such messages to dev_dbg() which can be turned on as
needed.
coresight: tmc-etr: Relax collection of trace from sysfs mode
Since the ETR now uses mode specific buffers, we can reliably
provide the trace data captured in sysfs mode, even when the ETR
is operating in PERF mode.
coresight: tmc-etr: Handle driver mode specific ETR buffers
Since the ETR could be driven either by SYSFS or by perf, it
becomes complicated how we deal with the buffers used for each
of these modes. The ETR driver cannot simply free the current
attached buffer without knowing the provider (i.e, sysfs vs perf).
To solve this issue, we provide:
1) the driver-mode specific etr buffer to be retained in the drvdata
2) the etr_buf for a session should be passed on when enabling the
hardware, which will be stored in drvdata->etr_buf. This will be
replaced (not free'd) as soon as the hardware is disabled, after
necessary sync operation.
The advantages of this are :
1) The common code path doesn't need to worry about how to dispose
an existing buffer, if it is about to start a new session with a
different buffer, possibly in a different mode.
2) The driver mode can control its buffers and can get access to the
saved session even when the hardware is operating in a different
mode. (e.g, we can still access a trace buffer from a sysfs mode
even if the etr is now used in perf mode, without disrupting the
current session.)
Towards this, we introduce a sysfs specific data which will hold the
etr_buf used for sysfs mode of operation, controlled solely by the
sysfs mode handling code.
coresight: perf: Disable trace path upon source error
We enable the trace path, before activating the source.
If we fail to enable the source, we must disable the path
to make sure it is available for another session.
At the moment, if there is no CPU specified for a given
event, we use cpu_online_mask and try to build path for
each of the CPUs in the mask. This could prevent any CPU
that is turned online later to be used for the tracing.
This patch changes to use the cpu_present_mask and tries
to build path for as much CPUs as possible ignoring the
failures in building path for some of the CPUs. If ever
we try to trace on those CPUs, we fail the operation.
We create a coresight trace path for each online CPU when
we start the event. We rely on the number of online CPUs
and then go on to allocate an array matching the "number of
online CPUs" for holding the path and then uses normal
CPU id as the index to the array. This is problematic as
we could have some offline CPUs causing us to access beyond
the actual array size (e.g, on a dual SMP system, if CPU0 is
offline, CPU1 could be really accessing beyond the array).
The solution is to switch to per-cpu array for holding the path.
The coresight components could be operated either in sysfs mode or in perf
mode. For some of the components, the mode of operation doesn't matter as
they simply relay the data to the next component in the trace path. But for
sinks, they need to be able to provide the trace data back to the user.
Thus we need to make sure that "mode" is handled appropriately. e.g,
the sysfs mode could have multiple sources driving the trace data, while
perf mode doesn't allow sharing the sink.
The coresight_enable_sink() however doesn't really allow this check to
trigger as it skips the "enable_sink" callback if the component is
already enabled, irrespective of the mode. This could cause mixing
of data from different modes or even same mode (in perf), if the
sources are different. Also, if we fail to enable the sink while
enabling a path (where sink is the first component enabled),
we could end up in disabling the components in the "entire"
path which were not enabled in this trial, causing disruptions
in the existing trace paths.
The coresight drivers relied on default bindings for graph
in DT, while reusing the "reg" field of the "ports" to indicate
the actual hardware port number for the connections. This can
cause duplicate ports with same addresses, but different
direction. However, with the rules getting stricter for the
address mismatch with the label, it is no longer possible to use
the port address field for the hardware port number.
This patch introduces new DT binding rules for coresight
components, based on the same generic DT graph bindings, but
avoiding the address duplication.
- All output ports must be specified under a child node with
name "out-ports".
- All input ports must be specified under a childe node with
name "in-ports".
- Port address should match the hardware port number.
The support for legacy bindings is retained, with a warning.
Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Rob Herring <robh@kernel.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The platform code parses the component connections and populates
a platform-description of the output connections in arrays of fields
(which is never freed). This is later copied in the coresight_register
to a newly allocated area, represented by coresight_connection(s).
This patch cleans up the code dealing with connections by making
use of the "coresight_connection" structure right at the platform
code and lets the generic driver simply re-use information provided
by the platform.
Thus making it reader friendly as well as avoiding the wastage of
unused memory.
When parsing the remote endpoint of an output port, we do :
rport = of_graph_get_remote_port(ep);
rparent = of_graph_get_remote_port_parent(ep);
and then parse the "remote_port" as if it was the remote endpoint,
which is wrong. The code worked fine because we used endpoint number
as the port number. Let us fix it and optimise a bit as:
remote_ep = of_graph_get_remote_endpoint(ep);
if (remote_ep)
remote_parent = of_graph_get_port_parent(remote_ep);
and then, parse the remote_ep for the port/endpoint details.
We don't drop the reference on the remote device while parsing the
connection, held by bus_find_device(). Fix this by duplicating the
device name and dropping the reference.
projects / kernel.git / log