summaryrefslogtreecommitdiff
path: root/drivers/misc/ocxl/file.c
AgeCommit message (Collapse)Author
2019-12-10ocxl: Fix concurrent AFU open and device removalFrederic Barrat
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: 75ca758adbaf ("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
2019-05-06ocxl: Fix return value check in afu_ioctl()Wei Yongjun
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: 060146614643 ("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>
2019-05-03ocxl: move event_fd handling to frontendAlastair D'Silva
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>
2019-05-03ocxl: afu_irq only deals with IRQ IDs, not offsetsAlastair D'Silva
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>
2019-05-03ocxl: Allow external drivers to use OpenCAPI contextsAlastair D'Silva
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>
2019-05-03ocxl: Create a clear delineation between ocxl backend & frontendAlastair D'Silva
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>
2019-05-03ocxl: Rename struct link to ocxl_linkAlastair D'Silva
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>
2018-06-05ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait()Wei Yongjun
Add the missing unlock before return from function afu_ioctl_enable_p9_wait() in the error handling case. Fixes: e948e06fc63a ("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>
2018-06-03ocxl: Add an IOCTL so userspace knows what OCXL features are availableAlastair D'Silva
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>
2018-06-03ocxl: Expose the thread_id needed for wait on POWER9Alastair D'Silva
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>
2018-03-02ocxl: Add get_metadata IOCTL to share OCXL information to userspaceAlastair D'Silva
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>
2018-02-21ocxl: Fix potential bad errno on irq allocationFrederic Barrat
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>
2018-02-14Merge tag 'powerpc-4.16-2' of ↵Linus Torvalds
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
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds
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>
2018-02-08ocxl: fix signed comparison with less than zeroColin Ian King
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: 5ef3166e8a32 ("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>
2018-01-24ocxl: Add AFU interrupt supportFrederic Barrat
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>
2018-01-24ocxl: Driver code for 'generic' opencapi devicesFrederic Barrat
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>