Commit Graph

7 Commits

Author SHA1 Message Date
Andrew Donnellan
8dde152ea3 cxl: fix leak of IRQ names in cxl_free_afu_irqs()
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>
2015-10-01 11:49:32 +10:00
Ian Munsie
55e07668fb cxl: Fix force unmapping mmaps of contexts allocated through the kernel api
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>
2015-08-30 18:47:26 +10:00
Ian Munsie
af2a50bb0c cxl: Fix + cleanup error paths in cxl_dev_context_init
If the cxl_context_alloc() call fails, we return immediately without
releasing the reference on the AFU device, allowing it to leak.

This patch switches to using goto style error handling so that the
device is released in common code for both error paths, and will also
simplify things if we add additional initialisation in this function in
the future.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-30 18:47:26 +10:00
Andrew Donnellan
7c26b9cf53 cxl: Allow release of contexts which have been OPENED but not STARTED
If we open a context but do not start it (either because we do not attempt
to start it, or because it fails to start for some reason), we are left
with a context in state OPENED. Previously, cxl_release_context() only
allowed releasing contexts in state CLOSED, so attempting to release an
OPENED context would fail.

In particular, this bug causes available contexts to run out after some EEH
failures, where drivers attempt to release contexts that have failed to
start.

Allow releasing contexts in any state with a value lower than STARTED, i.e.
OPENED or CLOSED (we can't release a STARTED context as it's currently
using the hardware, and we assume that contexts in any new states which may
be added in future with a value higher than STARTED are also unsafe to
release).

Cc: stable@vger.kernel.org
Fixes: 6f7f0b3df6 ("cxl: Add AFU virtual PHB and kernel API")
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-20 16:15:23 +10:00
Daniel Axtens
13e68d8bd0 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>
2015-08-14 21:32:07 +10:00
Michael Neuling
3f8dc44d88 cxl: Fix refcounting in kernel API
Currently the kernel API AFU dev refcounting is done on context start and stop.
This patch moves this refcounting to context init and release, bringing it
inline with how the userspace API does it.

Without this we've seen the refcounting on the AFU get out of whack between the
user and kernel API usage.  This causes the AFU structures to be freed when
they are actually still in use.

This fixes some kref warnings we've been seeing and spurious ErrIVTE IRQs.

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>
2015-07-07 19:38:37 +10:00
Michael Neuling
6f7f0b3df6 cxl: Add AFU virtual PHB and kernel API
This patch does two things.

Firstly it presents the Accelerator Function Unit (AFUs) behind the POWER
Service Layer (PSL) as PCI devices on a virtual PCI Host Bridge (vPHB).  This
in in addition to the PSL being a PCI device itself.

As part of the Coherent Accelerator Interface Architecture (CAIA) AFUs can
provide an AFU configuration.  This AFU configuration recored is architected to
be the same as a PCI config space.

This patch sets discovers the AFU configuration records, provides AFU config
space read/write functions to these configuration records.  It then enumerates
the PCI bus.  It also hooks in PCI ops where appropriate.  It also destroys the
vPHB when the physical card is removed.

Secondly, it add an in kernel API for AFU to use CXL.  AFUs must present a
driver that firstly binds as a PCI device.  This PCI device can then be using
to do CXL specific operations (that can't sit in the PCI ops) using this API.

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>
2015-06-03 13:27:20 +10:00