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  1. 25 11月, 2016 1 次提交
  3. 23 11月, 2016 1 次提交
  5. 18 11月, 2016 1 次提交
  7. 04 10月, 2016 1 次提交
  9. 09 8月, 2016 1 次提交
  11. 08 7月, 2016 4 次提交
    • P
      cxl: Refine slice error debug messages · 6e0c50f9
      由 Philippe Bergheaud 提交于 
      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: NPhilippe Bergheaud <felix@linux.vnet.ibm.com>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      6e0c50f9
    • I
      cxl: Workaround XSL bug that does not clear the RA bit after a reset · 2a4f667a
      由 Ian Munsie 提交于 
      An issue was noted in our debug logs where the XSL would leave the RA
bit asserted after an AFU reset operation, which would effectively
prevent further AFU reset operations from working.

Workaround the issue by clearing the RA bit with an MMIO write if it is
still asserted after any AFU control operation.
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Reviewed-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      2a4f667a
    • I
      cxl: Fix bug where AFU disable operation had no effect · 5e7823c9
      由 Ian Munsie 提交于 
      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: NIan Munsie <imunsie@au1.ibm.com>
Reviewed-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      5e7823c9
    • I
      cxl: Fix allocating a minimum of 2 pages for the SPA · 2224b671
      由 Ian Munsie 提交于 
      The Scheduled Process Area is allocated dynamically with enough pages to
fit at least as many processes as the AFU descriptor indicated. Since
the calculation is non-trivial, it does this by calculating how many
processes could fit in an allocation of a given order, and increasing
that order until it can fit enough processes or hits the maximum
supported size.

Currently, it will start this search using a SPA of 2 pages instead of
1. This can waste a page of memory if the AFU's maximum number of
supported processes was small enough to fit in one page.

Fix the algorithm to start the search at 1 page.
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Reviewed-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      2224b671
  13. 16 6月, 2016 2 次提交
    • F
      cxl: Abstract the differences between the PSL and XSL · 6d382616
      由 Frederic Barrat 提交于 
      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: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      6d382616
    • I
      cxl: Update process element after allocating interrupts · 292841b0
      由 Ian Munsie 提交于 
      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: NIan Munsie <imunsie@au1.ibm.com>
Reviewed-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      292841b0
  15. 11 5月, 2016 3 次提交
    • I
      cxl: Add kernel API to allow a context to operate with relocate disabled · 7a0d85d3
      由 Ian Munsie 提交于 
      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: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      7a0d85d3
    • I
      cxl: Ensure PSL interrupt is configured for contexts with no AFU IRQs · 3c206fa7
      由 Ian Munsie 提交于 
      In the cxl kernel API, it is possible to create a context and start it
without allocating any interrupts. Since we assign or allocate the PSL
interrupt when allocating AFU interrupts this will lead to a situation
where we start the context with no means to take any faults.

The user API is not affected as it always goes through the cxl interrupt
allocation code paths and will have the PSL interrupt allocated or
assigned, even if no AFU interrupts were requested.

This checks that at least one interrupt is configured at the time of
attach, and if not it will assign the multiplexed PSL interrupt for
powernv, or allocate a single interrupt for PowerVM.
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Reviewed-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      3c206fa7
    • I
      cxl: Handle num_of_processes larger than can fit in the SPA · 895a7980
      由 Ian Munsie 提交于 
      num_of_process is a 16 bit field, theoretically allowing an AFU to
support 16K processes, however the scheduled process area currently has
a maximum size of 1MB, which limits the maximum number of processes to
7704.

Some AFUs may not necessarily care what the limit is and just want to be
able to use the maximum by setting the field to 16K. To allow these to
work, detect this situation and use the maximum size for the SPA.

Downgrade the WARN_ON to a dev_warn.
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      895a7980
  17. 27 4月, 2016 1 次提交
  19. 09 3月, 2016 9 次提交
  21. 08 12月, 2015 1 次提交
  23. 07 10月, 2015 1 次提交
    • C
      cxl: Fix number of allocated pages in SPA · 4108efb0
      由 Christophe Lombard 提交于 
      The scheduled process area is currently allocated before assigning the
correct maximum processes to the AFU, which will mean we only ever
allocate a fixed number of pages for the scheduled process area. This
will limit us to 958 processes with 2 x 64K pages. If we try to use more
processes than that we'd probably overrun the buffer and corrupt memory
or crash.

AFUs that require three or more interrupts per process will not be
affected as they are already limited to less processes than that, but we
could hit it on an AFU that requires 0, 1 or 2 interrupts per process,
or when using 4K pages.

This patch moves the initialisation of the num_procs to before the SPA
allocation so that enough pages will be allocated for the number of
processes that the AFU supports.
Signed-off-by: NChristophe Lombard <clombard@linux.vnet.ibm.com>
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Cc: <stable@vger.kernel.org> # 3.18+
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      4108efb0
  25. 14 8月, 2015 2 次提交
    • D
      cxl: Allocate and release the SPA with the AFU · 05155772
      由 Daniel Axtens 提交于 
      Previously the SPA was allocated and freed upon entering and leaving
AFU-directed mode. This causes some issues for error recovery - contexts
hold a pointer inside the SPA, and they may persist after the AFU has
been detached.

We would ideally like to allocate the SPA when the AFU is allocated, and
release it until the AFU is released. However, we don't know how big the
SPA needs to be until we read the AFU descriptor.

Therefore, restructure the code:

 - Allocate the SPA only once, on the first attach.

 - Release the SPA only when the entire AFU is being released (not
   detached). Guard the release with a NULL check, so we don't free
   if it was never allocated (e.g. dedicated mode)
Acked-by: NCyril Bur <cyrilbur@gmail.com>
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      05155772
    • D
      cxl: Drop commands if the PCI channel is not in normal state · 0b3f9c75
      由 Daniel Axtens 提交于 
      If the PCI channel has gone down, don't attempt to poke the hardware.

We need to guard every time cxl_whatever_(read|write) is called. This
is because a call to those functions will dereference an offset into an
mmio register, and the mmio mappings get invalidated in the EEH
teardown.

Check in the read/write functions in the header.
We give them the same semantics as usual PCI operations:
 - a write to a channel that is down is ignored.
 - a read from a channel that is down returns all fs.

Also, we try to access the MMIO space of a vPHB device as part of the
PCI disable path. Because that's a read that bypasses most of our usual
checks, we handle it explicitly.

As far as user visible warnings go:
 - Check link state in file ops, return -EIO if down.
 - Be reasonably quiet if there's an error in a teardown path,
   or when we already know the hardware is going down.
 - Throw a big WARN if someone tries to start a CXL operation
   while the card is down. This gives a useful stacktrace for
   debugging whatever is doing that.
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      0b3f9c75
  27. 06 8月, 2015 1 次提交
  29. 13 7月, 2015 1 次提交
  31. 03 6月, 2015 4 次提交
  33. 22 1月, 2015 1 次提交
    • I
      cxl: Add tracepoints · 9bcf28cd
      由 Ian Munsie 提交于 
      This patch adds tracepoints throughout the cxl driver, which can provide
insight into:

- Context lifetimes
- Commands sent to the PSL and AFU and their completion status
- Segment and page table misses and their resolution
- PSL and AFU interrupts
- slbia calls from the powerpc copro_fault code

These tracepoints are mostly intended to aid in debugging (particularly
for new AFU designs), and may be useful standalone or in conjunction
with hardware traces collected by the PSL (read out via the trace
interface in debugfs) and AFUs.
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      9bcf28cd
  35. 29 12月, 2014 1 次提交
    • I
      cxl: Disable SPAP register when freeing SPA · db7933f3
      由 Ian Munsie 提交于 
      When we deactivate the AFU directed mode we free the scheduled process
area, but did not clear the register in the hardware that has a pointer
to it.

This should be fine since we will have already cleared out every context
and we won't do anything that would cause the hardware to access it
until after we have allocated a new one, but just to be safe this patch
clears out the register when we free the page.
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      db7933f3
  37. 12 12月, 2014 2 次提交
    • I
      cxl: Add timeout to process element commands · a98e6e9f
      由 Ian Munsie 提交于 
      In the event that something goes wrong in the hardware and it is unable
to complete a process element comment we would end up polling forever,
effectively making the associated process unkillable.

This patch adds a timeout to the process element command code path, so
that we will give up if the hardware does not respond in a reasonable
time.

Cc: stable@vger.kernel.org
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      a98e6e9f
    • I
      cxl: Change contexts_lock to a mutex to fix sleep while atomic bug · ee41d11d
      由 Ian Munsie 提交于 
      We had a known sleep while atomic bug if a CXL device was forcefully
unbound while it was in use. This could occur as a result of EEH, or
manually induced with something like this while the device was in use:

echo 0000:01:00.0 > /sys/bus/pci/drivers/cxl-pci/unbind

The issue was that in this code path we iterated over each context and
forcefully detached it with the contexts_lock spin lock held, however
the detach also needed to take the spu_mutex, and call schedule.

This patch changes the contexts_lock to a mutex so that we are not in
atomic context while doing the detach, thereby avoiding the sleep while
atomic.

Also delete the related TODO comment, which suggested an alternate
solution which turned out to not be workable.

Cc: stable@vger.kernel.org
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      ee41d11d
  39. 27 11月, 2014 1 次提交
    • I
      CXL: Return error to PSL if IRQ demultiplexing fails & print clearer warning · 27bbcef2
      由 Ian Munsie 提交于 
      If an AFU has a hardware bug that causes it to acknowledge a context
terminate or remove while that context has outstanding transactions, it
is possible for the kernel to receive an interrupt for that context
after we have removed it from the context list.

The kernel will not be able to demultiplex the interrupt (or worse - if
we have already reallocated the process handle we could mis-attribute it
to the new context), and printed a big scary warning.

It did not acknowledge the interrupt, which would effectively halt
further translation fault processing on the PSL.

This patch makes the warning clearer about the likely cause of the issue
(i.e. hardware bug) to make it obvious to future AFU designers of what
needs to be fixed. It also prints out the process handle which can then
be matched up with hardware and software traces for debugging.

It also acknowledges the interrupt to the PSL with either an address
error or acknowledge, so that the PSL can continue with other
translations.
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      27bbcef2
  41. 18 11月, 2014 1 次提交
    • I
      cxl: Return error to PSL if IRQ demultiplexing fails & print clearer warning · bc78b05b
      由 Ian Munsie 提交于 
      If an AFU has a hardware bug that causes it to acknowledge a context
terminate or remove while that context has outstanding transactions, it
is possible for the kernel to receive an interrupt for that context
after we have removed it from the context list.

The kernel will not be able to demultiplex the interrupt (or worse - if
we have already reallocated the process handle we could mis-attribute it
to the new context), and printed a big scary warning.

It did not acknowledge the interrupt, which would effectively halt
further translation fault processing on the PSL.

This patch makes the warning clearer about the likely cause of the issue
(i.e. hardware bug) to make it obvious to future AFU designers of what
needs to be fixed. It also prints out the process handle which can then
be matched up with hardware and software traces for debugging.

It also acknowledges the interrupt to the PSL with either an address
error or acknowledge, so that the PSL can continue with other
translations.
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      bc78b05b