Commit aac8da6517 ("intel_th: msu: Start handling IRQs") implicitly
relies on the use of devm_request_irq() to subsequently free the irqs on
device removal, but in case of the pci_free_irq_vectors() API, the
handlers need to be freed before it is called. Therefore, at the moment
the driver's remove path trips a BUG_ON(irq_has_action()):
> kernel BUG at drivers/pci/msi.c:375!
> invalid opcode: 0000 1 SMP
> CPU: 2 PID: 818 Comm: rmmod Not tainted 5.5.0-rc1+ #1
> RIP: 0010:free_msi_irqs+0x67/0x1c0
> pci_disable_msi+0x116/0x150
> pci_free_irq_vectors+0x1b/0x20
> intel_th_pci_remove+0x22/0x30 [intel_th_pci]
> pci_device_remove+0x3e/0xb0
> device_release_driver_internal+0xf0/0x1c0
> driver_detach+0x4c/0x8f
> bus_remove_driver+0x5c/0xd0
> driver_unregister+0x31/0x50
> pci_unregister_driver+0x40/0x90
> intel_th_pci_driver_exit+0x10/0xad6 [intel_th_pci]
> __x64_sys_delete_module+0x147/0x290
> ? exit_to_usermode_loop+0xd7/0x120
> do_syscall_64+0x57/0x1b0
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fix this by explicitly freeing irqs before freeing the vectors. We keep
using the devm_* variants because they are still useful in early error
paths.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: aac8da6517 ("intel_th: msu: Start handling IRQs")
Reported-by: Ammy Yi <ammy.yi@intel.com>
Tested-by: Ammy Yi <ammy.yi@intel.com>
Cc: stable@vger.kernel.org # v5.2+
Link: https://lore.kernel.org/r/20191217115527.74383-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for asserting window switch trigger when tracing to MSU output
ports. This allows for software controlled switching between windows of
the MSU buffer, which can be used for double buffering while exporting the
trace data further from the MSU.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The code that waits for the pipeline empty condition of the MSU is
currently called in the path that disables the trace. We will also
need this in the window switch trigger sequence. Therefore, factor
out this code and make it accessible to the GTH device.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The only type of IRQ triggering event that is useful to us at the moment
is the "last block" interrupt of the MSU. This interrupt can only be
enabled via "MINTCTL" register that doesn't exist in earlier version of
the Intel TH.
Enumerate the presence of MINTCTL via per-device driver data structure
and only instantiate the IRQ resource for subdevices if this capability
is present.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We intend to use the interrupt to detect Last Block condition in the MSU
driver, which we can use for double-buffering software-managed data
transfers.
Add an interrupt handler to the MSU driver.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since Intel TH is capable of MSI interrupt signalling, make use of it.
The way it works is, each of the 7 interrupt triggering events has its
own vector in this mode, as opposed to interrupt line delivery, where
all events are signalled via the same line. Failing to enable MSI, the
driver falls back to using an interrupt line.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, the IRQ is passed between the glue layers and the core as a
separate argument, while the MMIO resources are passed as resources.
This also limits the number of IRQs thus used to one, while the current
versions of Intel TH use a different MSI vector for each interrupt
triggering event, of which there are 7.
Change this to pass IRQ in the resources array.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In some versions of Intel TH, the Software Trace Hub (STH) has a second
MMIO BAR dedicated to the input from Intel PT. This calls for a new
subdevice that will be enumerated if the corresponding BAR is present.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, MMIO resource numbers in the TH driver core correspond to
PCI BAR numbers, because in the beginning there was only the PCI glue
layer. This created some confusion when the ACPI glue layer was added.
To avoid confusion and remove glue-specific code from the driver core,
split the resource indices between core and glue layers and change the
API so that the driver core receives the MMIO resources in the same
fixed order. At the same time, make the IRQ always be a parameter to
intel_th_alloc() instead of sometimes passing it as a resource.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some devices can only operate in host mode, so we need means of
communicating this to the core driver on per-device basis. This
adds a flag to drvdata to signal host-only capability to the core.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
This adds SPDX GPL-2.0 header to the Trace Hub driver and removes the
GPLv2 boilerplate text.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
On some devices (TH 2.x devices at the moment), the internal time counter
is initially not synchronized to the global crystal clock, so the time
stamps it produces will not be useful. In this case, the driver needs
to force the time counter resync.
This applies the workaround to relevant devices.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
A glue layer may want to install its own hooks into trace capture start
and stop paths to apply workarounds. This adds optional callbacks.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Trace Hub 2.x adds Low Power Path (LPP) output port type, which provides
a low power mode trace path from sources to PTI or BSSB.
This adds an output subdevice for the LPP port.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Instead of allocating devices for every possible output subdevice,
allow the switch to allocate only the ones that it knows about.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
The switch (GTH) does not directly interact with SOURCE type devices and
may not even be present (in host mode). To reflect this and avoid
inconsistencies between target and host mode, make SOURCE devices
descendant directly from the root (i.e. PCI) device. Their symlinks
will no longer appear under the switch device, but they can still
be found under intel_th bus.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Output subdevices that rely on other output subdevices (or otherwise
don't directly talk to an output port on the switch) don't need to be
assigned an output port either.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
This patch adds a 'host_mode' module option to enable host-driven
operational mode in the driver. In this mode, the driver does not
perform trace configuration or enable trace capture, but still
provides all the means necessary for software trace sources to
write their data to the Trace Hub. This means that the debug host
takes care of all the configuration and enabling and we do not
interfere.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
These are:
* a fix for a modprobe time deadlock
* a new PCI ID for Kaby Lake PCH-H
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Merge tag 'stm-for-greg-20160714' of git://git.kernel.org/pub/scm/linux/kernel/git/ash/stm into char-misc-next
Alexander writes:
intel_th: Fixes -t://git.kernel.org/pub/scm/linux/kernel/git/ash/stm.git
tags/stm-for-greg-20160714
stable
These are:
* a fix for a modprobe time deadlock
* a new PCI ID for Kaby Lake PCH-H
Driver initialization tries to request a hub (GTH) driver module from
its probe callback, resulting in a deadlock.
This patch solves the problem by adding a deferred work for requesting
the hub module.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: <stable@vger.kernel.org> # 4.4.x-
'output' type device callbacks are missing from the kerneldoc description
of the 'intel_th_driver' structure. Fix this.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
If output subdevice driver is not loaded, activating it will try to
call its ->activate method and crash. Fix this by explicitly checking
for the driver.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
Some subdevices (MSU, PTI) need to register their own driver-specific
attribute groups. Provide a way for those to pass their attribute
groups to the core driver in their driver structure so that the
core can take care of creating and removing them.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
Intel TH implements a scratchpad register to indicate to the firmware
and external debuggers what trace configuration is enabled so that
everybody plays nicely together. The register is a bit field and the
bit assignment convention is described in the developer's manual.
This patch enables the driver to automatically set scratchpad register
bits according to the output configuration that's enabled.
Based on work by Yann Fouassier.
Signed-off-by: Yann Fouassier <yann.fouassier@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Intel(R) Trace Hub (TH) is a set of hardware blocks (subdevices) that
produce, switch and output trace data from multiple hardware and
software sources over several types of trace output ports encoded
in System Trace Protocol (MIPI STPv2) and is intended to perform
full system debugging.
For these subdevices, we create a bus, where they can be discovered
and configured by userspace software.
This patch creates this bus infrastructure, three types of devices
(source, output, switch), resource allocation, some callback mechanisms
to facilitate communication between the subdevices' drivers and some
common sysfs attributes.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Alexander Shishkin