Commit Graph

19 Commits

Author SHA1 Message Date
Minghao Chi
30e120e6a9 ocxl: remove redundant rc variable
Return value from ocxl_context_attach() directly instead
of taking this in another redundant variable.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211215060438.441918-1-chi.minghao@zte.com.cn
2021-12-20 12:15:33 +11:00
Zheng Yongjun
52f6b0a90b ocxl: use DEFINE_MUTEX() for mutex lock
mutex lock can be initialized automatically with DEFINE_MUTEX()
rather than explicitly calling mutex_init().

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201224132446.31286-1-zhengyongjun3@huawei.com
2021-01-30 11:39:21 +11:00
Frederic Barrat
a58d37bce0 ocxl: Fix concurrent AFU open and device removal
If an ocxl device is unbound through sysfs at the same time its AFU is
being opened by a user process, the open code may dereference freed
stuctures, which can lead to kernel oops messages. You'd have to hit a
tiny time window, but it's possible. It's fairly easy to test by
making the time window bigger artificially.

Fix it with a combination of 2 changes:
  - when an AFU device is found in the IDR by looking for the device
    minor number, we should hold a reference on the device until after
    the context is allocated. A reference on the AFU structure is kept
    when the context is allocated, so we can release the reference on
    the device after the context allocation.
  - with the fix above, there's still another even tinier window,
    between the time the AFU device is found in the IDR and the
    reference on the device is taken. We can fix this one by removing
    the IDR entry earlier, when the device setup is removed, instead
    of waiting for the 'release' device callback. With proper locking
    around the IDR.

Fixes: 75ca758adb ("ocxl: Create a clear delineation between ocxl backend & frontend")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190624144148.32022-1-fbarrat@linux.ibm.com
2019-12-10 20:34:23 +11:00
Wei Yongjun
6be6a8de1b ocxl: Fix return value check in afu_ioctl()
In case of error, the function eventfd_ctx_fdget() returns ERR_PTR() and
never returns NULL. The NULL test in the return value check should be
replaced with IS_ERR().

This issue was detected by using the Coccinelle software.

Fixes: 0601466146 ("ocxl: move event_fd handling to frontend")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-06 20:21:56 +10:00
Alastair D'Silva
0601466146 ocxl: move event_fd handling to frontend
Event_fd is only used in the driver frontend, so it does not
need to exist in the backend code. Relocate it to the frontend
and provide an opaque mechanism for consumers instead.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 02:55:02 +10:00
Alastair D'Silva
2ec3b7ed2a ocxl: afu_irq only deals with IRQ IDs, not offsets
The use of offsets is required only in the frontend, so alter
the IRQ API to only work with IRQ IDs in the backend.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 02:55:02 +10:00
Alastair D'Silva
b9721d275c ocxl: Allow external drivers to use OpenCAPI contexts
Most OpenCAPI operations require a valid context, so
exposing these functions to external drivers is necessary.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 02:55:02 +10:00
Alastair D'Silva
75ca758adb ocxl: Create a clear delineation between ocxl backend & frontend
The OCXL driver contains both frontend code for interacting with userspace,
as well as backend code for interacting with the hardware.

This patch separates the backend code from the frontend so that it can be
used by other device drivers that communicate via OpenCAPI.

Relocate dev, cdev & sysfs files to the frontend code to allow external
drivers to maintain their own devices.

Reference counting on the device in the backend is replaced with kref
counting.

Move file & sysfs layer initialisation from core.c (backend) to
pci.c (frontend).

Create an ocxl_function oriented interface for initing devices &
enumerating AFUs.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 02:55:01 +10:00
Alastair D'Silva
9c4ae06456 ocxl: Rename struct link to ocxl_link
The term 'link' is ambiguous (especially when the struct is used for a
list), so rename it for clarity.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 02:55:00 +10:00
Wei Yongjun
2e5c93d6bb ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait()
Add the missing unlock before return from function
afu_ioctl_enable_p9_wait() in the error handling case.

Fixes: e948e06fc6 ("ocxl: Expose the thread_id needed for wait on POWER9")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-05 21:33:57 +10:00
Alastair D'Silva
02a8e5bc1c ocxl: Add an IOCTL so userspace knows what OCXL features are available
In order for a userspace AFU driver to call the POWER9 specific
OCXL_IOCTL_ENABLE_P9_WAIT, it needs to verify that it can actually
make that call.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:32 +10:00
Alastair D'Silva
e948e06fc6 ocxl: Expose the thread_id needed for wait on POWER9
In order to successfully issue as_notify, an AFU needs to know the TID
to notify, which in turn means that this information should be
available in userspace so it can be communicated to the AFU.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:32 +10:00
Alastair D'Silva
07c5ccd70a ocxl: Add get_metadata IOCTL to share OCXL information to userspace
Some required information is not exposed to userspace currently (eg. the
PASID), pass this information back, along with other information which
is currently communicated via sysfs, which saves some parsing effort in
userspace.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-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>
2018-03-02 13:02:14 +11:00
Frederic Barrat
423688abd9 ocxl: Fix potential bad errno on irq allocation
Fix some issues found by a static checker:

When allocating an AFU interrupt, if the driver cannot copy the output
parameters to userland, the errno value was not set to EFAULT

Remove a (now) useless cast.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-21 11:21:01 +11:00
Linus Torvalds
694a20dae6 powerpc fixes for 4.16 #2
A larger batch of fixes than we'd like. Roughly 1/3 fixes for new code, 1/3
 fixes for stable and 1/3 minor things.
 
 There's four commits fixing bugs when using 16GB huge pages on hash, caused by
 some of the preparatory changes for pkeys.
 
 Two fixes for bugs in the enhanced IRQ soft masking for local_t, one of which
 broke KVM in some circumstances.
 
 Four fixes for Power9. The most bizarre being a bug where futexes stopped
 working because a NULL pointer dereference didn't trap during early boot (it
 aliased the kernel mapping). A fix for memory hotplug when using the Radix MMU,
 and a fix for live migration of guests using the Radix MMU.
 
 Two fixes for hotplug on pseries machines. One where we weren't correctly
 updating NUMA info when CPUs are added and removed. And the other fixes
 crashes/hangs seen when doing memory hot remove during boot, which is apparently
 a thing people do.
 
 Finally a handful of build fixes for obscure configs and other minor fixes.
 
 Thanks to:
   Alexey Kardashevskiy, Aneesh Kumar K.V, Balbir Singh, Colin Ian King, Daniel
   Henrique Barboza, Florian Weimer, Guenter Roeck, Harish, Laurent Vivier,
   Madhavan Srinivasan, Mauricio Faria de Oliveira, Nathan Fontenot, Nicholas
   Piggin, Sam Bobroff.
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Merge tag 'powerpc-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "A larger batch of fixes than we'd like. Roughly 1/3 fixes for new
  code, 1/3 fixes for stable and 1/3 minor things.

  There's four commits fixing bugs when using 16GB huge pages on hash,
  caused by some of the preparatory changes for pkeys.

  Two fixes for bugs in the enhanced IRQ soft masking for local_t, one
  of which broke KVM in some circumstances.

  Four fixes for Power9. The most bizarre being a bug where futexes
  stopped working because a NULL pointer dereference didn't trap during
  early boot (it aliased the kernel mapping). A fix for memory hotplug
  when using the Radix MMU, and a fix for live migration of guests using
  the Radix MMU.

  Two fixes for hotplug on pseries machines. One where we weren't
  correctly updating NUMA info when CPUs are added and removed. And the
  other fixes crashes/hangs seen when doing memory hot remove during
  boot, which is apparently a thing people do.

  Finally a handful of build fixes for obscure configs and other minor
  fixes.

  Thanks to: Alexey Kardashevskiy, Aneesh Kumar K.V, Balbir Singh, Colin
  Ian King, Daniel Henrique Barboza, Florian Weimer, Guenter Roeck,
  Harish, Laurent Vivier, Madhavan Srinivasan, Mauricio Faria de
  Oliveira, Nathan Fontenot, Nicholas Piggin, Sam Bobroff"

* tag 'powerpc-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  selftests/powerpc: Fix to use ucontext_t instead of struct ucontext
  powerpc/kdump: Fix powernv build break when KEXEC_CORE=n
  powerpc/pseries: Fix build break for SPLPAR=n and CPU hotplug
  powerpc/mm/hash64: Zero PGD pages on allocation
  powerpc/mm/hash64: Store the slot information at the right offset for hugetlb
  powerpc/mm/hash64: Allocate larger PMD table if hugetlb config is enabled
  powerpc/mm: Fix crashes with 16G huge pages
  powerpc/mm: Flush radix process translations when setting MMU type
  powerpc/vas: Don't set uses_vas for kernel windows
  powerpc/pseries: Enable RAS hotplug events later
  powerpc/mm/radix: Split linear mapping on hot-unplug
  powerpc/64s/radix: Boot-time NULL pointer protection using a guard-PID
  ocxl: fix signed comparison with less than zero
  powerpc/64s: Fix may_hard_irq_enable() for PMI soft masking
  powerpc/64s: Fix MASKABLE_RELON_EXCEPTION_HV_OOL macro
  powerpc/numa: Invalidate numa_cpu_lookup_table on cpu remove
2018-02-14 10:06:41 -08:00
Linus Torvalds
a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00
Colin Ian King
dedab7f0d3 ocxl: fix signed comparison with less than zero
Currently the comparison of used < 0 is always false because
uses is a size_t. Fix this by making used a ssize_t type.

Detected by Coccinelle:
drivers/misc/ocxl/file.c:320:6-10: WARNING: Unsigned expression
compared with zero: used < 0

Fixes: 5ef3166e8a ("ocxl: Driver code for 'generic' opencapi devices")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-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>
2018-02-08 23:56:11 +11:00
Frederic Barrat
aeddad1760 ocxl: Add AFU interrupt support
Add user APIs through ioctl to allocate, free, and be notified of an
AFU interrupt.

For opencapi, an AFU can trigger an interrupt on the host by sending a
specific command targeting a 64-bit object handle. On POWER9, this is
implemented by mapping a special page in the address space of a
process and a write to that page will trigger an interrupt.

Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-24 11:42:58 +11:00
Frederic Barrat
5ef3166e8a ocxl: Driver code for 'generic' opencapi devices
Add an ocxl driver to handle generic opencapi devices. Of course, it's
not meant to be the only opencapi driver, any device is free to
implement its own. But if a host application only needs basic services
like attaching to an opencapi adapter, have translation faults handled
or allocate AFU interrupts, it should suffice.

The AFU config space must follow the opencapi specification and use
the expected vendor/device ID to be seen by the generic driver.

The driver exposes the device AFUs as a char device in /dev/ocxl/

Note that the driver currently doesn't handle memory attached to the
opencapi device.

Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-24 11:42:58 +11:00