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2018-06-03Merge branch 'fixes' into nextMichael Ellerman1-0/+8
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.
2018-06-02cxl: Disable prefault_mode in Radix modeVaibhav Jain1-1/+3
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 <snip> 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 <vaibhav@linux.ibm.com> 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>
2018-05-15cxl: Report the tunneled operations statusPhilippe Bergheaud1-0/+8
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 <felix@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-19cxl: Prevent adapter reset if an active context existsVaibhav Jain1-2/+5
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 <fbarrat@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-22cxl: Allow initialization on timebase sync failuresFrederic Barrat1-0/+8
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 <fbarrat@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09cxl: sysfs support for guestsChristophe Lombard1-5/+5
Filter out a few adapter parameters which don't make sense in a guest. Document the changes. Co-authored-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-14cxl: Allow the kernel to trust that an image won't change on PERST.Daniel Axtens1-0/+10
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>
2015-06-03cxl: Document external user of existing APIMichael Neuling1-0/+22
Now that libcxl is public, let's document it. 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>
2015-06-03cxl: Export AFU error buffer via sysfsVaibhav Jain1-0/+11
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 <mikey@neuling.org> Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-27cxl: Fix a typo in ABI documentationPhilippe Bergheaud1-1/+1
Fix the attribute name of the configuration record class ID. Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-02-06cxl: Export optional AFU configuration record in sysfsIan Munsie1-0/+37
An AFU may optionally contain one or more PCIe like configuration records, which can be used to identify the AFU. This patch adds support for exposing the raw config space and the vendor, device and class code under sysfs. These will appear in a subdirectory of the AFU device corresponding with the configuration record number, e.g. cat /sys/class/cxl/afu0.0/cr0/vendor 0x1014 cat /sys/class/cxl/afu0.0/cr0/device 0x4350 cat /sys/class/cxl/afu0.0/cr0/class 0x120000 hexdump -C /sys/class/cxl/afu0.0/cr0/config 00000000 14 10 50 43 00 00 00 00 06 00 00 12 00 00 00 00 |..PC............| 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000100 These files behave in much the same way as the equivalent files for PCI devices, with one exception being that the config file is currently read-only and restricted to the root user. It is not necessarily required to be this strict, but we currently do not have a compelling use-case to make it writable and/or world-readable, so I erred on the side of being restrictive. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-01-22cxl: Add ability to reset the cardRyan Grimm1-0/+7
Adds reset to sysfs which will PERST the card. If load_image_on_perst is set to "user" or "factory", the PERST will cause that image to be loaded. load_image_on_perst is set to "user" for production. "none" could be used for debugging. The PSL trace arrays are preserved which then can be read through debugfs. PERST also triggers CAPP recovery. An HMI comes in, which is handled by EEH. EEH unbinds the driver, calls into Sapphire to reinitialize the PHB, then rebinds the driver. Signed-off-by: Ryan Grimm <grimm@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-01-22cxl: Add image control to sysfsRyan Grimm1-0/+14
load_image_on_perst identifies whether a PERST will cause the image to be flashed to the card. And if so, which image. Valid entries are: "none", "user" and "factory". A value of "none" means PERST will not cause the image to be flashed. A power cycle to the pcie slot is required to load the image. "user" loads the user provided image and "factory" loads the factory image upon PERST. sysfs updates the cxl struct in the driver then calls cxl_update_image_control to write the vals in the VSEC. Signed-off-by: Ryan Grimm <grimm@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-01-22cxl: Update CXL ABI documentationPhilippe Bergheaud1-3/+8
This fixes two typos and explains where shared attributes are stored. Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-08cxl: Add documentation for userspace APIsIan Munsie1-0/+129
This documentation gives an overview of the hardware architecture, userspace APIs via /dev/cxl/afuM.N and the syfs files. It also adds a MAINTAINERS file entry for cxl. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>