cxl: Report the tunneled operations status

Failure to synchronize the tunneled operations does not prevent
the initialization of the cxl card. This patch reports the tunneled
operati

cxl: Report the tunneled operations status

Failure to synchronize the tunneled operations does not prevent
the initialization of the cxl card. This patch reports the tunneled
operations status via /sys.

Signed-off-by: Philippe Bergheaud <felix@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: Prevent adapter reset if an active context exists

This patch prevents resetting the cxl adapter via sysfs in presence of
one or more active cxl_context on it. This protects against

cxl: Prevent adapter reset if an active context exists

This patch prevents resetting the cxl adapter via sysfs in presence of
one or more active cxl_context on it. This protects against an
unrecoverable error caused by PSL owning a dirty cache line even after
reset and host tries to touch the same cache line. In case a force reset
of the card is required irrespective of any active contexts, the int
value -1 can be stored in the 'reset' sysfs attribute of the card.

The patch introduces a new atomic_t member named contexts_num inside
struct cxl that holds the number of active context attached to the card
, which is checked against '0' before proceeding with the reset. To
prevent against a race condition where a context is activated just after
reset check is performed, the contexts_num is atomically set to '-1'
after reset-check to indicate that no more contexts can be activated on
the card anymore.

Before activating a context we atomically test if contexts_num is
non-negative and if so, increment its value by one. In case the value of
contexts_num is negative then it indicates that the card is about to be
reset and context activation is error-ed out at that point.

Fixes: 62fa19d4b4fd ("cxl: Add ability to reset the card")
Cc: stable@vger.kernel.org # v4.0+
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: Allow initialization on timebase sync failures

Failure to synchronize the PSL timebase currently prevents the
initialization of the cxl card, thus rendering the card useless. This

cxl: Allow initialization on timebase sync failures

Failure to synchronize the PSL timebase currently prevents the
initialization of the cxl card, thus rendering the card useless. This
is too extreme for a feature which is rarely used, if at all. No
hardware AFUs or software is currently using PSL timebase.

This patch still tries to synchronize the PSL timebase when the card
is initialized, but ignores the error if it can't. Instead, it reports
a status via /sys.

Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: sysfs support for guests

Filter out a few adapter parameters which don't make sense in a guest.
Document the changes.

Co-authored-by: Frederic Barrat <fbarrat@linux.vnet.ib

cxl: sysfs support for guests

Filter out a few adapter parameters which don't make sense in a guest.
Document the changes.

Co-authored-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: Allow the kernel to trust that an image won't change on PERST.

Provide a kernel API and a sysfs entry which allow a user to specify
that when a card is PERSTed, it's image will stay

cxl: Allow the kernel to trust that an image won't change on PERST.

Provide a kernel API and a sysfs entry which allow a user to specify
that when a card is PERSTed, it's image will stay the same, allowing
it to participate in EEH.

cxl_reset is used to reflash the card. In that case, we cannot safely
assert that the image will not change. Therefore, disallow cxl_reset
if the flag is set.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: Document external user of existing API

Now that libcxl is public, let's document it.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ib

cxl: Document external user of existing API

Now that libcxl is public, let's document it.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: Export AFU error buffer via sysfs

Export the "AFU Error Buffer" via sysfs attribute (afu_err_buf). AFU
error buffer is used by the AFU to report application specific
errors. The

cxl: Export AFU error buffer via sysfs

Export the "AFU Error Buffer" via sysfs attribute (afu_err_buf). AFU
error buffer is used by the AFU to report application specific
errors. The contents of this buffer are AFU specific and are intended to
be interpreted by the application interacting with the afu.

Suggested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: Fix a typo in ABI documentation

Fix the attribute name of the configuration record class ID.

Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Signed-off-by: Mic

cxl: Fix a typo in ABI documentation

Fix the attribute name of the configuration record class ID.

Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: Export optional AFU configuration record in sysfs

An AFU may optionally contain one or more PCIe like configuration
records, which can be used to identify the AFU.

This pat

cxl: Export optional AFU configuration record in sysfs

An AFU may optionally contain one or more PCIe like configuration
records, which can be used to identify the AFU.

This patch adds support for exposing the raw config space and the
vendor, device and class code under sysfs. These will appear in a
subdirectory of the AFU device corresponding with the configuration
record number, e.g.

cat /sys/class/cxl/afu0.0/cr0/vendor
0x1014

cat /sys/class/cxl/afu0.0/cr0/device
0x4350

cat /sys/class/cxl/afu0.0/cr0/class
0x120000

hexdump -C /sys/class/cxl/afu0.0/cr0/config
00000000 14 10 50 43 00 00 00 00 06 00 00 12 00 00 00 00 |..PC............|
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000100

These files behave in much the same way as the equivalent files for PCI
devices, with one exception being that the config file is currently
read-only and restricted to the root user. It is not necessarily
required to be this strict, but we currently do not have a compelling
use-case to make it writable and/or world-readable, so I erred on the
side of being restrictive.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: Add ability to reset the card

Adds reset to sysfs which will PERST the card. If load_image_on_perst is set
to "user" or "factory", the PERST will cause that image to be loaded.

cxl: Add ability to reset the card

Adds reset to sysfs which will PERST the card. If load_image_on_perst is set
to "user" or "factory", the PERST will cause that image to be loaded.

load_image_on_perst is set to "user" for production.

"none" could be used for debugging. The PSL trace arrays are preserved which
then can be read through debugfs.

PERST also triggers CAPP recovery. An HMI comes in, which is handled by EEH.
EEH unbinds the driver, calls into Sapphire to reinitialize the PHB, then
rebinds the driver.

Signed-off-by: Ryan Grimm <grimm@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: Add image control to sysfs

load_image_on_perst identifies whether a PERST will cause the image to be
flashed to the card. And if so, which image.

Valid entries are: "none",

cxl: Add image control to sysfs

load_image_on_perst identifies whether a PERST will cause the image to be
flashed to the card. And if so, which image.

Valid entries are: "none", "user" and "factory".

A value of "none" means PERST will not cause the image to be flashed. A
power cycle to the pcie slot is required to load the image.

"user" loads the user provided image and "factory" loads the factory image upon
PERST.

sysfs updates the cxl struct in the driver then calls cxl_update_image_control
to write the vals in the VSEC.

Signed-off-by: Ryan Grimm <grimm@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: Update CXL ABI documentation

This fixes two typos and explains where shared attributes are stored.

Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Acked-by: Mi

cxl: Update CXL ABI documentation

This fixes two typos and explains where shared attributes are stored.

Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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cxl: Add documentation for userspace APIs

This documentation gives an overview of the hardware architecture, userspace
APIs via /dev/cxl/afuM.N and the syfs files. It also adds a MAINTAI

cxl: Add documentation for userspace APIs

This documentation gives an overview of the hardware architecture, userspace
APIs via /dev/cxl/afuM.N and the syfs files. It also adds a MAINTAINERS file
entry for cxl.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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