The service layer API (in cxl.h) lists some low-level functions whose
implementation is different on PSL8, PSL9 and XSL:
- Init implementation for the adapter and the afu.
- Invalidate TLB/SLB.
- Attach process for dedicated/directed models.
- Handle psl interrupts.
- Debug registers for the adapter and the afu.
- Traces.
Each environment implements its own functions, and the common code uses
them through function pointers, defined in cxl_service_layer_ops.
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The mm_struct corresponding to the current task is acquired each time
an interrupt is raised. So to simplify the code, we only get the
mm_struct when attaching an AFU context to the process.
The mm_count reference is increased to ensure that the mm_struct can't
be freed. The mm_struct will be released when the context is detached.
A reference on mm_users is not kept to avoid a circular dependency if
the process mmaps its cxl mmio and forget to unmap before exiting.
The field glpid (pid of the group leader associated with the pid), of
the structure cxl_context, is removed because it's no longer useful.
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The two previously fields pid and tid, located in the structure
cxl_irq_info, are only used in the guest environment. To avoid confusion,
it's not necessary to fill the fields in the bare-metal environment.
Pid_tid is now renamed to 'reserved' to avoid undefined behavior on
bare-metal. The PSL Process and Thread Identification Register
(CXL_PSL_PID_TID_An) is only used when attaching a dedicated process
for PSL8 only. This register goes away in CAIA2.
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 14a3ae34bf ("cxl: Prevent read/write to AFU config space while AFU
not configured") introduced a rwsem to fix an invalid memory access that
occurred when someone attempts to access the config space of an AFU on a
vPHB whilst the AFU is deconfigured, such as during EEH recovery.
It turns out that it's possible to run into a nested locking issue when EEH
recovery fails and a full device hotplug is required.
cxl_pci_error_detected() deconfigures the AFU, taking a writer lock on
configured_rwsem. When EEH recovery fails, the EEH code calls
pci_hp_remove_devices() to remove the device, which in turn calls
cxl_remove() -> cxl_pci_remove_afu() -> pci_deconfigure_afu(), which tries
to grab the writer lock that's already held.
Standard rwsem semantics don't express what we really want to do here and
don't allow for nested locking. Fix this by replacing the rwsem with an
atomic_t which we can control more finely. Allow the AFU to be locked
multiple times so long as there are no readers.
Fixes: 14a3ae34bf ("cxl: Prevent read/write to AFU config space while AFU not configured")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Stub out the debugfs functions so that the build doesn't break when
CONFIG_DEBUG_FS=n.
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
During EEH recovery, we deconfigure all AFUs whilst leaving the
corresponding vPHB and virtual PCI device in place.
If something attempts to interact with the AFU's PCI config space (e.g.
running lspci) after the AFU has been deconfigured and before it's
reconfigured, cxl_pcie_{read,write}_config() will read invalid values from
the deconfigured struct cxl_afu and proceed to Oops when they try to
dereference pointers that have been set to NULL during deconfiguration.
Add a rwsem to struct cxl_afu so we can prevent interaction with config
space while the AFU is deconfigured.
Reported-by: Pradipta Ghosh <pradghos@in.ibm.com>
Suggested-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.9+
Signed-off-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>
If a process dumps core while owning a cxl file descriptor obtained
from an AFU driver (e.g. cxlflash) through the cxl_get_fd() API, the
following error occurs:
[ 868.027591] Unable to handle kernel paging request for data at address ...
[ 868.027778] Faulting instruction address: 0xc00000000035edb0
cpu 0x8c: Vector: 300 (Data Access) at [c000003c688275e0]
pc: c00000000035edb0: elf_core_dump+0xd60/0x1300
lr: c00000000035ed80: elf_core_dump+0xd30/0x1300
sp: c000003c68827860
msr: 9000000100009033
dar: c
dsisr: 40000000
current = 0xc000003c68780000
paca = 0xc000000001b73200 softe: 0 irq_happened: 0x01
pid = 46725, comm = hxesurelock
enter ? for help
[c000003c68827a60] c00000000036948c do_coredump+0xcec/0x11e0
[c000003c68827c20] c0000000000ce9e0 get_signal+0x540/0x7b0
[c000003c68827d10] c000000000017354 do_signal+0x54/0x2b0
[c000003c68827e00] c00000000001777c do_notify_resume+0xbc/0xd0
[c000003c68827e30] c000000000009838 ret_from_except_lite+0x64/0x68
--- Exception: 300 (Data Access) at 00003fff98ad2918
The root cause is that the address_space structure for the file
doesn't define a 'host' member.
When cxl allocates a file descriptor, it's using the anonymous inode
to back the file, but allocates a private address_space for each
context. The private address_space allows to track memory allocation
for each context. cxl doesn't define the 'host' member of the address
space, i.e. the inode. We don't want to define it as the anonymous
inode, since there's no longer a 1-to-1 relation between address_space
and inode.
To fix it, instead of using the anonymous inode, we introduce a simple
pseudo filesystem so that cxl can allocate its own inodes. So we now
have one inode for each file and address_space. The pseudo filesystem
is only mounted on the first allocation of a file descriptor by
cxl_get_fd().
Tested with cxlflash.
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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: 62fa19d4b4 ("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>
If the capi link is going down while the PSL owns a dirty cache line,
any access from the host for that data could lead to an Uncorrectable
Error.
So when resetting the capi adapter through sysfs, make sure the PSL
cache is flushed. It won't help if there are any active Process
Elements on the card, as the cache would likely get new dirty cache
lines immediately, but if resetting an idle adapter, it should avoid
any bad surprises from data left over from terminated Process Elements.
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit f67a6722d6 ("cxl: Workaround PE=0 hardware limitation in
Mellanox CX4") added a "min_pe" field to struct cxl_service_layer_ops,
to allow us to work around a Mellanox CX-4 hardware limitation.
When allocating the PE number in cxl_context_init(), we read from
ctx->afu->adapter->native->sl_ops->min_pe to get the minimum PE number.
Unsurprisingly, in a PowerVM guest ctx->afu->adapter->native is NULL,
and guests don't have a cxl_service_layer_ops struct anywhere.
Move min_pe from struct cxl_service_layer_ops to struct cxl so it's
accessible in both native and PowerVM environments. For the Mellanox
CX-4, set the min_pe value in set_sl_ops().
Fixes: f67a6722d6 ("cxl: Workaround PE=0 hardware limitation in Mellanox CX4")
Reported-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The CX4 card cannot cope with a context with PE=0 due to a hardware
limitation, resulting in:
[ 34.166577] command failed, status limits exceeded(0x8), syndrome 0x5a7939
[ 34.166580] mlx5_core 0000:01:00.1: Failed allocating uar, aborting
Since the kernel API allocates a default context very early during
device init that will almost certainly get Process Element ID 0 there is
no easy way for us to extend the API to allow the Mellanox to inform us
of this limitation ahead of time.
Instead, work around the issue by extending the XSL structure to include
a minimum PE to allocate. Although the bug is not in the XSL, it is the
easiest place to work around this limitation given that the CX4 is
currently the only card that uses an XSL.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The Mellanox CX4 in cxl mode uses a hybrid interrupt model, where
interrupts are routed from the networking hardware to the XSL using the
MSIX table, and from there will be transformed back into an MSIX
interrupt using the cxl style interrupts (i.e. using IVTE entries and
ranges to map a PE and AFU interrupt number to an MSIX address).
We want to hide the implementation details of cxl interrupts as much as
possible. To this end, we use a special version of the MSI setup &
teardown routines in the PHB while in cxl mode to allocate the cxl
interrupts and configure the IVTE entries in the process element.
This function does not configure the MSIX table - the CX4 card uses a
custom format in that table and it would not be appropriate to fill that
out in generic code. The rest of the functionality is similar to the
"Full MSI-X mode" described in the CAIA, and this could be easily
extended to support other adapters that use that mode in the future.
The interrupts will be associated with the default context. If the
maximum number of interrupts per context has been limited (e.g. by the
mlx5 driver), it will automatically allocate additional kernel contexts
to associate extra interrupts as required. These contexts will be
started using the same WED that was used to start the default context.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The Mellanox CX4 has a hardware limitation where only 4 bits of the
AFU interrupt number can be passed to the XSL when sending an interrupt,
limiting it to only 15 interrupts per context (AFU interrupt number 0 is
invalid).
In order to overcome this, we will allocate additional contexts linked
to the default context as extra address space for the extra interrupts -
this will be implemented in the next patch.
This patch adds the preliminary support to allow this, by way of adding
a linked list in the context structure that we use to keep track of the
contexts dedicated to interrupts, and an API to simultaneously iterate
over the related context structures, AFU interrupt numbers and hardware
interrupt numbers. The point of using a single API to iterate these is
to hide some of the details of the iteration from external code, and to
reduce the number of APIs that need to be exported via base.c to allow
built in code to call.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The cxl kernel API has a concept of a default context associated with
each PCI device under the virtual PHB. The Mellanox CX4 will also use
the cxl kernel API, but it does not use a virtual PHB - rather, the AFU
appears as a physical function as a peer to the networking functions.
In order to allow the kernel API to work with those networking
functions, we will need to associate a default context with them as
well. To this end, refactor the corresponding code to do this in vphb.c
and export it so that it can be called from the PHB code.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The Mellanox CX4 uses a model where the AFU is one physical function of
the device, and is used by other peer physical functions of the same
device. This will require those other devices to grab a reference on the
AFU when they are initialised to make sure that it does not go away
during their lifetime.
Move the AFU refcount functions to base.c so they can be called from
the PHB code.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The PSL Slice Error Register (PSL_SERR_An) reports implementation
dependent AFU errors, in the form of a bitmap. The PSL_SERR_An
register content is printed in the form of hex dump debug message.
This patch decodes the PSL_ERR_An register contents, and prints a
specific error message for each possible error bit. It also dumps
the secondary registers AFU_ERR_An and PSL_DSISR_An, that may
contain extra debug information.
This patch also removes the large WARN message that used to report
the cxl slice error interrupt, and replaces it by a short informative
message, that draws attention to AFU implementation errors.
Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The AFU disable operation has a bug where it will not clear the enable
bit and therefore will have no effect. To date this has likely been
masked by fact that we perform an AFU reset before the disable, which
also has the effect of clearing the enable bit, making the following
disable operation effectively a noop on most hardware. This patch
modifies the afu_control function to take a parameter to clear from the
AFU control register so that the disable operation can clear the
appropriate bit.
This bug was uncovered on the Mellanox CX4, which uses an XSL rather
than a PSL. On the XSL the reset operation will not complete while the
AFU is enabled, meaning the enable bit was still set at the start of the
disable and as a result this bug was hit and the disable also timed out.
Because of this difference in behaviour between the PSL and XSL, this
patch now makes the reset dependent on the card using a PSL to avoid
waiting for a timeout on the XSL. It is entirely possible that we may be
able to drop the reset altogether if it turns out we only ever needed it
due to this bug - however I am not willing to drop it without further
regression testing and have added comments to the code explaining the
background.
This also fixes a small issue where the AFU_Cntl register was read
outside of the lock that protects it.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This provides AFU drivers a means to associate private data with a cxl
context. This is particularly intended for make the new callbacks for
driver specific events easier for AFU drivers to use, as they can easily
get back to any private data structures they may use.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds an afu_driver_ops structure with fetch_event() and
event_delivered() callbacks. An AFU driver such as cxlflash can fill
this out and associate it with a context to enable passing custom AFU
specific events to userspace.
This also adds a new kernel API function cxl_context_pending_events(),
that the AFU driver can use to notify the cxl driver that new specific
events are ready to be delivered, and wake up anyone waiting on the
context wait queue.
The current count of AFU driver specific events is stored in the field
afu_driver_events of the context structure.
The cxl driver checks the afu_driver_events count during poll, select,
read, etc. calls to check if an AFU driver specific event is pending,
and calls fetch_event() to obtain and deliver that event. This way, the
cxl driver takes care of all the usual locking semantics around these
calls and handles all the generic cxl events, so that the AFU driver
only needs to worry about it's own events.
fetch_event() return a struct cxl_event_afu_driver_reserved, allocated
by the AFU driver, and filled in with the specific event information and
size. Total event size (header + data) should not be greater than
CXL_READ_MIN_SIZE (4K).
Th cxl driver prepends an appropriate cxl event header, copies the event
to userspace, and finally calls event_delivered() to return the status of
the operation to the AFU driver. The event is identified by the context
and cxl_event_afu_driver_reserved pointers.
Since AFU drivers provide their own means for userspace to obtain the
AFU file descriptor (i.e. cxlflash uses an ioctl on their scsi file
descriptor to obtain the AFU file descriptor) and the generic cxl driver
will never use this event, the ABI of the event is up to each individual
AFU driver.
Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds support for using CAPP DMA mode, which is required for XSL
based cards such as the Mellanox CX4 to function.
This is currently an RFC as it depends on the corresponding support to
be merged into skiboot first, which was submitted here:
http://patchwork.ozlabs.org/patch/625582/
In the event that the skiboot on the system does not have the above
support, it will indicate as such in the kernel log and abort the init
process.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The XSL (Translation Service Layer) is a stripped down version of the
PSL (Power Service Layer) used in some cards such as the Mellanox CX4.
Like the PSL, it implements the CAIA architecture, but has a number of
differences, mostly in it's implementation dependent registers. This
adds an ops structure to abstract these differences to bring initial
support for XSL CAPI devices.
The XSL does not implement the optional architected SERR register,
however while it treats it as a reserved register and should work with
no special treatment, attempting to access it will cause the XSL_FEC
(First Error Capture) register to be filled out, preventing it from
capturing any subsequent errors. Therefore, this patch also prevents the
kernel from trying to set up the SERR register so that the FEC register
may still be useful, and to save one interrupt.
The XSL also uses a special DMA cxl mode, which uses a slightly
different init sequence for the CAPP and PHB. The kernel support for
this will be in a future patch once the corresponding support has been
merged into skiboot.
Co-authored-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In the kernel API, it is possible to attempt to allocate AFU interrupts
after already starting a context. Since the process element structure
used by the hardware is only filled out at the time the context is
started, it will not be updated with the interrupt numbers that have
just been allocated and therefore AFU interrupts will not work unless
they were allocated prior to starting the context.
This can present some difficulties as each CAPI enabled PCI device in
the kernel API has a default context, which may need to be started very
early to enable translations, potentially before interrupts can easily
be set up.
This patch makes the API more flexible to allow interrupts to be
allocated after a context has already been started and takes care of
updating the PE structure used by the hardware and notifying it to
discard any cached copy it may have.
The update is currently performed via a terminate/remove/add sequence.
This is necessary on some hardware such as the XSL that does not
properly support the update LLCMD.
Note that this is only supported on powernv at present - attempting to
perform this ordering on PowerVM will raise a warning.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Highlights:
- Support for Power ISA 3.0 (Power9) Radix Tree MMU from Aneesh Kumar K.V
- Live patching support for ppc64le (also merged via livepatching.git)
Various cleanups & minor fixes from:
- Aaro Koskinen, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
Chris Smart, Daniel Axtens, Frederic Barrat, Gavin Shan, Ian Munsie, Lennart
Sorensen, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring, Michael
Ellerman, Oliver O'Halloran, Paul Gortmaker, Paul Mackerras, Rashmica Gupta,
Russell Currey, Suraj Jitindar Singh, Thiago Jung Bauermann, Valentin
Rothberg, Vipin K Parashar.
General:
- Update LMB associativity index during DLPAR add/remove from Nathan Fontenot
- Fix branching to OOL handlers in relocatable kernel from Hari Bathini
- Add support for userspace Power9 copy/paste from Chris Smart
- Always use STRICT_MM_TYPECHECKS from Michael Ellerman
- Add mask of possible MMU features from Michael Ellerman
PCI:
- Enable pass through of NVLink to guests from Alexey Kardashevskiy
- Cleanups in preparation for powernv PCI hotplug from Gavin Shan
- Don't report error in eeh_pe_reset_and_recover() from Gavin Shan
- Restore initial state in eeh_pe_reset_and_recover() from Gavin Shan
- Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" from Guilherme G. Piccoli
- Remove the dependency on EEH struct in DDW mechanism from Guilherme G. Piccoli
selftests:
- Test cp_abort during context switch from Chris Smart
- Add several tests for transactional memory support from Rashmica Gupta
perf:
- Add support for sampling interrupt register state from Anju T
- Add support for unwinding perf-stackdump from Chandan Kumar
cxl:
- Configure the PSL for two CAPI ports on POWER8NVL from Philippe Bergheaud
- Allow initialization on timebase sync failures from Frederic Barrat
- Increase timeout for detection of AFU mmio hang from Frederic Barrat
- Handle num_of_processes larger than can fit in the SPA from Ian Munsie
- Ensure PSL interrupt is configured for contexts with no AFU IRQs from Ian Munsie
- Add kernel API to allow a context to operate with relocate disabled from Ian Munsie
- Check periodically the coherent platform function's state from Christophe Lombard
Freescale:
- Updates from Scott: "Contains 86xx fixes, minor device tree fixes, an erratum
workaround, and a kconfig dependency fix."
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Merge tag 'powerpc-4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Highlights:
- Support for Power ISA 3.0 (Power9) Radix Tree MMU from Aneesh Kumar K.V
- Live patching support for ppc64le (also merged via livepatching.git)
Various cleanups & minor fixes from:
- Aaro Koskinen, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
Chris Smart, Daniel Axtens, Frederic Barrat, Gavin Shan, Ian Munsie,
Lennart Sorensen, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring,
Michael Ellerman, Oliver O'Halloran, Paul Gortmaker, Paul Mackerras,
Rashmica Gupta, Russell Currey, Suraj Jitindar Singh, Thiago Jung
Bauermann, Valentin Rothberg, Vipin K Parashar.
General:
- Update LMB associativity index during DLPAR add/remove from Nathan
Fontenot
- Fix branching to OOL handlers in relocatable kernel from Hari Bathini
- Add support for userspace Power9 copy/paste from Chris Smart
- Always use STRICT_MM_TYPECHECKS from Michael Ellerman
- Add mask of possible MMU features from Michael Ellerman
PCI:
- Enable pass through of NVLink to guests from Alexey Kardashevskiy
- Cleanups in preparation for powernv PCI hotplug from Gavin Shan
- Don't report error in eeh_pe_reset_and_recover() from Gavin Shan
- Restore initial state in eeh_pe_reset_and_recover() from Gavin Shan
- Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell"
from Guilherme G Piccoli
- Remove the dependency on EEH struct in DDW mechanism from Guilherme
G Piccoli
selftests:
- Test cp_abort during context switch from Chris Smart
- Add several tests for transactional memory support from Rashmica
Gupta
perf:
- Add support for sampling interrupt register state from Anju T
- Add support for unwinding perf-stackdump from Chandan Kumar
cxl:
- Configure the PSL for two CAPI ports on POWER8NVL from Philippe
Bergheaud
- Allow initialization on timebase sync failures from Frederic Barrat
- Increase timeout for detection of AFU mmio hang from Frederic
Barrat
- Handle num_of_processes larger than can fit in the SPA from Ian
Munsie
- Ensure PSL interrupt is configured for contexts with no AFU IRQs
from Ian Munsie
- Add kernel API to allow a context to operate with relocate disabled
from Ian Munsie
- Check periodically the coherent platform function's state from
Christophe Lombard
Freescale:
- Updates from Scott: "Contains 86xx fixes, minor device tree fixes,
an erratum workaround, and a kconfig dependency fix."
* tag 'powerpc-4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (192 commits)
powerpc/86xx: Fix PCI interrupt map definition
powerpc/86xx: Move pci1 definition to the include file
powerpc/fsl: Fix build of the dtb embedded kernel images
powerpc/fsl: Fix rcpm compatible string
powerpc/fsl: Remove FSL_SOC dependency from FSL_LBC
powerpc/fsl-pci: Add a workaround for PCI 5 errata
powerpc/fsl: Fix SPI compatible on t208xrdb and t1040rdb
powerpc/powernv/npu: Add PE to PHB's list
powerpc/powernv: Fix insufficient memory allocation
powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism
Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell"
powerpc/eeh: Drop unnecessary label in eeh_pe_change_owner()
powerpc/eeh: Ignore handlers in eeh_pe_reset_and_recover()
powerpc/eeh: Restore initial state in eeh_pe_reset_and_recover()
powerpc/eeh: Don't report error in eeh_pe_reset_and_recover()
Revert "powerpc/powernv: Exclude root bus in pnv_pci_reset_secondary_bus()"
powerpc/powernv/npu: Enable NVLink pass through
powerpc/powernv/npu: Rework TCE Kill handling
powerpc/powernv/npu: Add set/unset window helpers
powerpc/powernv/ioda2: Export debug helper pe_level_printk()
...
In the PowerVM environment, the PHYP CoherentAccel component manages
the state of the Coherent Accelerator Processor Interface adapter and
virtualizes CAPI resources, handles CAPP, PSL, PSL Slice errors - and
interrupts - and provides a new set of hcalls for the OS APIs to utilize
Accelerator Function Unit (AFU).
During the course of operation, a coherent platform function can
encounter errors. Some possible reason for errors are:
• Hardware recoverable and unrecoverable errors
• Transient and over-threshold correctable errors
PHYP implements its own state model for the coherent platform function.
The state of the AFU is available through a hcall.
The current implementation of the cxl driver, for the PowerVM
environment, checks this state of the AFU only when an action is
requested - open a device, ioctl command, memory map, attach/detach a
process - from an external driver - cxlflash, libcxl. If an error is
detected the cxl driver handles the error according the content of the
Power Architecture Platform Requirements document.
But in case of low-level troubles (or error injection), the PHYP
component may reset the card and change the AFU state. The PHYP
interface doesn't provide any way to be notified when that happens thus
implies that the cxl driver:
• cannot handle immediatly the state change of the AFU.
• cannot notify other drivers (cxlflash, ...)
The purpose of this patch is to wake up the cpu periodically to check
the current state of each AFU and to see if we need to enter an error
recovery path.
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
cxl devices typically access memory using an MMU in much the same way as
the CPU, and each context includes a state register much like the MSR in
the CPU. Like the CPU, the state register includes a bit to enable
relocation, which we currently always enable.
In some cases, it may be desirable to allow a device to access memory
using real addresses instead of effective addresses, so this adds a new
API, cxl_set_translation_mode, that can be used to disable relocation
on a given kernel context. This can allow for the creation of a special
privileged context that the device can use if it needs relocation
disabled, and can use regular contexts at times when it needs relocation
enabled.
This interface is only available to users of the kernel API for obvious
reasons, and will never be supported in a virtualised environment.
This will be used by the upcoming cxl support in the mlx5 driver.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
These defines are not used, but other equivalent definitions
(CXL_SPA_SW_CMD_*) are used. Remove the unused defines.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When detaching contexts, we may still have interrupts in the system
which are yet to be delivered to any CPU and be acked in the PSL.
This can result in a subsequent unrelated process getting an spurious
IRQ or an interrupt for a non-existent context.
This polls the PSL to ensure that the PSL is clear of IRQs for the
detached context, before removing the context from the idr.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Tested-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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>
Add a check at the beginning of cxl_probe function to ignore virtual pci
devices created for each afu registered. This fixes the the errors
messages logged about missing CXL vsec, when cxl probe is unable to
find necessary vsec entries in device pci config space. The error
message logged are of the form :
cxl-pci 0004:00:00.0: ABORTING: CXL VSEC not found!
cxl-pci 0004:00:00.0: cxl_init_adapter failed: -19
Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reviewed-by: fbarrat@linux.vnet.ibm.com
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Check the AFU state whenever an API is called. The hypervisor may
issue a reset of the adapter when it detects a fault. When it happens,
it launches an error recovery which will either move the AFU to a
permanent failure state, or in the disabled state.
If the AFU is found to be disabled, detach all existing contexts from
it before issuing a AFU reset to re-enable it.
Before detaching contexts, notify any kernel driver through the EEH
callbacks of the AFU pci device.
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>
Like on bare-metal, the cxl driver creates a virtual PHB and a pci
device for the AFU. The configuration space of the device is mapped to
the configuration record of the AFU.
Reuse the code defined in afu_cr_read8|16|32() when reading the
configuration space of the AFU device.
Even though the (virtual) AFU device is a pci device, the adapter is
not. So a driver using the cxl kernel API cannot read the VPD of the
adapter through the usual PCI interface. Therefore, we add a call to
the cxl kernel API:
ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count);
Co-authored-by: Christophe Lombard <clombard@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>
The new flash.c file contains the logic to flash a new image on the
adapter, through a hcall. It is an iterative process, with chunks of
data of 1M at a time. There are also 2 phases: write and verify. The
flash operation itself is driven from a user-land tool.
Once flashing is successful, an rtas call is made to update the device
tree with the new properties values for the adapter and the AFU(s)
Add a new char device for the adapter, so that the flash tool can
access the card, even if there is no valid AFU on it.
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>
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>
The new of.c file contains code to parse the device tree to find out
about cxl adapters and AFUs.
guest.c implements the guest-specific callbacks for the backend API.
The process element ID is not known until the context is attached, so
we have to separate the context ID assigned by the cxl driver from the
process element ID visible to the user applications. In bare-metal,
the 2 IDs match.
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>
[mpe: Fix SMP=n build, fix PSERIES=n build, minor whitespace fixes]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Introduce sub-structures containing the bare-metal specific fields in
the structures describing the adapter (struct cxl) and AFU (struct
cxl_afu).
Update all their references.
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>
The hypervisor calls provide an interface with a coherent platform
facility and function. It matches version 0.16 of the 'PAPR changes'
document.
The following hcalls are supported:
H_ATTACH_CA_PROCESS Attach a process element to a coherent platform
function.
H_DETACH_CA_PROCESS Detach a process element from a coherent
platform function.
H_CONTROL_CA_FUNCTION Allow the partition to manipulate or query
certain coherent platform function behaviors.
H_COLLECT_CA_INT_INFO Collect interrupt info about a coherent.
platform function after an interrupt occurred
H_CONTROL_CA_FAULTS Control the operation of a coherent platform
function after a fault occurs.
H_DOWNLOAD_CA_FACILITY Support for downloading a base adapter image to
the coherent platform facility, and for
validating the entire image after the download.
H_CONTROL_CA_FACILITY Allow the partition to manipulate or query
certain coherent platform facility behaviors.
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>
A few functions are mostly common between bare-metal and guest and
just need minor tuning. To avoid crowding the backend API, introduce a
few 'if' based on the CPU being in HV mode.
Co-authored-by: Christophe Lombard <clombard@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>
Rename a few functions, changing the 'cxl_' prefix to either
'cxl_pci_' or 'cxl_native_', to make clear that the implementation is
bare-metal specific.
Those functions will have an equivalent implementation for a guest in
a later patch.
Co-authored-by: Christophe Lombard <clombard@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>
The backend API (in cxl.h) lists some low-level functions whose
implementation is different on bare-metal and in a guest. Each
environment implements its own functions, and the common code uses
them through function pointers, defined in cxl_backend_ops
Co-authored-by: Christophe Lombard <clombard@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>
Move a few functions around to better separate code specific to
bare-metal environment from code which will be commonly used between
guest and bare-metal.
Code specific to bare-metal is meant to be in native.c or pci.c
only. It's basically anything which touches the card p1 registers,
some p2 registers not needed from a guest and the PCI interface.
Co-authored-by: Christophe Lombard <clombard@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>
Move around some functions which will be accessed from the bare-metal
and guest environments.
Code in native.c and pci.c is meant to be bare-metal specific.
Other files contain code which may be shared with guests.
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>
Presently when a user-space process issues CXL_IOCTL_START_WORK ioctl we
store the pid of the current task_struct and use it to get pointer to
the mm_struct of the process, while processing page or segment faults
from the capi card. However this causes issues when the thread that had
originally issued the start-work ioctl exits in which case the stored
pid is no more valid and the cxl driver is unable to handle faults as
the mm_struct corresponding to process is no more accessible.
This patch fixes this issue by using the mm_struct of the next alive
task in the thread group. This is done by iterating over all the tasks
in the thread group starting from thread group leader and calling
get_task_mm on each one of them. When a valid mm_struct is obtained the
pid of the associated task is stored in the context replacing the
exiting one for handling future faults.
The patch introduces a new function named get_mem_context that checks if
the current task pointed to by ctx->pid is dead? If yes it performs the
steps described above. Also a new variable cxl_context.glpid is
introduced which stores the pid of the thread group leader associated
with the context owning task.
Reported-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reported-by: Frank Haverkamp <HAVERKAM@de.ibm.com>
Suggested-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
An idr warning is reported when a context is release after the capi card
is unbound from the cxl driver via sysfs. Below are the steps to
reproduce:
1. Create multiple afu contexts in an user-space application using libcxl.
2. Unbind capi card from cxl using command of form
echo <capi-card-pci-addr> > /sys/bus/pci/drivers/cxl-pci/unbind
3. Exit/kill the application owning afu contexts.
After above steps a warning message is usually seen in the kernel logs
of the form "idr_remove called for id=<context-id> which is not
allocated."
This is caused by the function cxl_release_afu which destroys the
contexts_idr table. So when a context is release no entry for context pe
is found in the contexts_idr table and idr code prints this warning.
This patch fixes this issue by increasing & decreasing the ref-count on
the afu device when a context is initialized or when its freed
respectively. This prevents the afu from being released until all the
afu contexts have been released. The patch introduces two new functions
namely cxl_afu_get/put that manage the ref-count on the afu device.
Also the patch removes code inside cxl_dev_context_init that increases ref
on the afu device as its guaranteed to be alive during this function.
Reported-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
cxl_free_afu_irqs() doesn't free IRQ names when it releases an AFU's IRQ
ranges. The userspace API equivalent in afu_release_irqs() calls
afu_irq_name_free() to release the IRQ names.
Call afu_irq_name_free() in cxl_free_afu_irqs() to release the IRQ names.
Make afu_irq_name_free() non-static to allow this.
Reported-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Fixes: 6f7f0b3df6 ("cxl: Add AFU virtual PHB and kernel API")
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch configures the PSL Timebase function and enables it,
after the CAPP has been initialized by OPAL.
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The cxl user api uses the address_space associated with the file when we
need to force unmap all cxl mmap regions (e.g. on eeh, driver detach,
etc). Currently, contexts allocated through the kernel api do not do
this and instead skip the mmap invalidation, potentially allowing them
to poke at the hardware after such an event, which may cause all sorts
of trouble.
This patch allocates an address_space for cxl contexts allocated through
the kernel api so that the same invalidate path will for these contexts
as well. We don't use the anonymous inode's address_space, as doing so
could invalidate any mmaps of completely unrelated drivers using
anonymous file descriptors.
This patch also introduces a kernelapi flag, so we know when freeing the
context if the address_space was allocated by us and needs to be freed.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
userspace programs using cxl currently have to use two strategies for
dealing with MMIO errors simultaneously. They have to check every read
for a return of all Fs in case the adapter has gone away and the kernel
has not yet noticed, and they have to deal with SIGBUS in case the
kernel has already noticed, invalidated the mapping and marked the
context as failed.
In order to simplify things, this patch adds an alternative approach
where the kernel will return a page filled with Fs instead of delivering
a SIGBUS. This allows userspace to only need to deal with one of these
two error paths, and is intended for use in libraries that use cxl
transparently and may not be able to safely install a signal handler.
This approach will only work if certain constraints are met. Namely, if
the application is both reading and writing to an address in the problem
state area it cannot assume that a non-FF read is OK, as it may just be
reading out a value it has previously written. Further - since only one
page is used per context a write to a given offset would be visible when
reading the same offset from a different page in the mapping (this only
applies within a single context, not between contexts).
An application could deal with this by e.g. making sure it also reads
from a read-only offset after any reads to a read/write offset.
Due to these constraints, this functionality must be explicitly
requested by userspace when starting the context by passing in the
CXL_START_WORK_ERR_FF flag.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
EEH (Enhanced Error Handling) allows a driver to recover from the
temporary failure of an attached PCI card. Enable basic CXL support
for EEH.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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>
