talos-op-linux/Documentation/ABI/testing/sysfs-class-cxl, branch master

ABI: fix some syntax issues at the ABI database

2019-06-14T16:17:11+00:00

On those three files, the ABI representation described at README are violated. - at sysfs-bus-iio-proximity-as3935: a ':' character is missing after "What" - at sysfs-class-devfreq: there's a typo at Description - at sysfs-class-cxl, it is using the ":" character at a file preamble, causing it to be misinterpreted as a tag. - On the other files, instead of "What", they use "Where". Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Mauro Carvalho Chehab Acked-by: Rafael J. Wysocki Acked-by: Andrew Donnellan # cxl Signed-off-by: Greg Kroah-Hartman

Merge branch 'fixes' into next

2018-06-03T10:32:02+00:00

We ended up with an ugly conflict between fixes and next in ftrace.h involving multiple nested ifdefs, and the automatic resolution is wrong. So merge fixes into next so we can fix it up.

cxl: Disable prefault_mode in Radix mode

2018-06-01T15:48:05+00:00

Currently we see a kernel-oops reported on Power-9 while attaching a context to an AFU, with radix-mode and sysfs attr 'prefault_mode' set to anything other than 'none'. The backtrace of the oops is of this form: Unable to handle kernel paging request for data at address 0x00000080 Faulting instruction address: 0xc00800000bcf3b20 cpu 0x1: Vector: 300 (Data Access) at [c00000037f003800] pc: c00800000bcf3b20: cxl_load_segment+0x178/0x290 [cxl] lr: c00800000bcf39f0: cxl_load_segment+0x48/0x290 [cxl] sp: c00000037f003a80 msr: 9000000000009033 dar: 80 dsisr: 40000000 current = 0xc00000037f280000 paca = 0xc0000003ffffe600 softe: 3 irq_happened: 0x01 pid = 3529, comm = afp_no_int cxl_prefault+0xfc/0x248 [cxl] process_element_entry_psl9+0xd8/0x1a0 [cxl] cxl_attach_dedicated_process_psl9+0x44/0x130 [cxl] native_attach_process+0xc0/0x130 [cxl] afu_ioctl+0x3f4/0x5e0 [cxl] do_vfs_ioctl+0xdc/0x890 ksys_ioctl+0x68/0xf0 sys_ioctl+0x40/0xa0 system_call+0x58/0x6c The issue is caused as on Power-8 the AFU attr 'prefault_mode' was used to improve initial storage fault performance by prefaulting process segments. However on Power-9 with radix mode we don't have Storage-Segments that we can prefault. Also prefaulting process Pages will be too costly and fine-grained. Hence, since the prefaulting mechanism doesn't makes sense of radix-mode, this patch updates prefault_mode_store() to not allow any other value apart from CXL_PREFAULT_NONE when radix mode is enabled. Fixes: f24be42aab37 ("cxl: Add psl9 specific code") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Vaibhav Jain Acked-by: Frederic Barrat Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman

cxl: Report the tunneled operations status

2018-05-15T11:30:01+00:00

Failure to synchronize the tunneled operations does not prevent the initialization of the cxl card. This patch reports the tunneled operations status via /sys. Signed-off-by: Philippe Bergheaud Signed-off-by: Michael Ellerman

cxl: Prevent adapter reset if an active context exists

2016-10-19T09:35:39+00:00

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: 62fa19d4b4fd ("cxl: Add ability to reset the card") Cc: stable@vger.kernel.org # v4.0+ Acked-by: Frederic Barrat Reviewed-by: Andrew Donnellan Signed-off-by: Vaibhav Jain Signed-off-by: Michael Ellerman

cxl: Allow initialization on timebase sync failures

2016-04-22T11:45:44+00:00

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 Acked-by: Ian Munsie Signed-off-by: Michael Ellerman

cxl: sysfs support for guests

2016-03-09T12:39:40+00:00

Filter out a few adapter parameters which don't make sense in a guest. Document the changes. Co-authored-by: Frederic Barrat Signed-off-by: Frederic Barrat Signed-off-by: Christophe Lombard Reviewed-by: Manoj Kumar Acked-by: Ian Munsie Signed-off-by: Michael Ellerman

cxl: Allow the kernel to trust that an image won't change on PERST.

2015-08-14T11:32:07+00:00

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 Signed-off-by: Michael Ellerman

cxl: Document external user of existing API

2015-06-03T03:27:16+00:00

Now that libcxl is public, let's document it. Signed-off-by: Michael Neuling Acked-by: Ian Munsie Signed-off-by: Michael Ellerman

cxl: Export AFU error buffer via sysfs

2015-06-03T03:27:15+00:00

Export the "AFU Error Buffer" via sysfs attribute (afu_err_buf). AFU error buffer is used by the AFU to report application specific errors. The contents of this buffer are AFU specific and are intended to be interpreted by the application interacting with the afu. Suggested-by: Michael Neuling Signed-off-by: Vaibhav Jain Signed-off-by: Michael Ellerman