lwn.git/arch/powerpc/platforms/powernv/powernv.h, branch v5.7-rc2

powerpc/powernv: Add ultravisor message log interface

2019-08-29T23:40:16+00:00

The ultravisor (UV) provides an in-memory console which follows the OPAL in-memory console structure. This patch extends the OPAL msglog code to initialize the UV memory console and provide the "/sys/firmware/ultravisor/msglog" interface for userspace to view the UV message log. Signed-off-by: Claudio Carvalho Signed-off-by: Michael Ellerman Tested-by: Claudio Carvalho Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190828130521.26764-2-mpe@ellerman.id.au

powerpc/powernv: process all OPAL event interrupts with kopald

2018-06-03T10:40:30+00:00

Using irq_work for processing OPAL event interrupts is not necessary. irq_work is typically used to schedule work from NMI context, a softirq may be more appropriate. However OPAL events are not particularly performance or latency critical, so they can all be invoked by kopald. This patch removes the irq_work queueing, and instead wakes up kopald when there is an event to be processed. kopald processes interrupts individually, enabling irqs and calling cond_resched between each one to minimise latencies. Event handlers themselves should still use threaded handlers, workqueues, etc. as necessary to avoid high interrupts-off latencies within any single interrupt. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

powerpc/powernv: Flush console before platform error reboot

2017-08-31T04:26:03+00:00

Unrecovered MCE and HMI errors are sent through a special restart OPAL call to log the platform error. The downside is that they don't go through normal Linux crash paths, so they don't give much information to the Linux console. Change this by providing a special crash function which does some of the console flushing from the panic() path before calling firmware to reboot. The downside of this is a little more code to execute before reaching the firmware reboot. However in practice, it's critical to get the Linux console messages output in order to debug a problem. So this is a desirable tradeoff. Note on the implementation: It is difficult to plumb a custom reboot handler into the panic path, because panic does a little bit too much work. For example, it will try to delay with the timebase, but that may be corrupted in some cases resulting in a hang without reaching the platform reboot. Another problem is that panic can invoke the crash dump code which is not what we want in the case of a hardware platform error. Long-term the best solution will be to rework the panic path so it can be suitable for this kind of panic, but for now we just duplicate a bit of the code. Signed-off-by: Nicholas Piggin Reviewed-by: Mahesh Salgaonkar Signed-off-by: Michael Ellerman

powerpc/powernv: Move CPU-Offline idle state invocation from smp.c to idle.c

2017-04-10T22:45:09+00:00

Move the piece of code in powernv/smp.c::pnv_smp_cpu_kill_self() which transitions the CPU to the deepest available platform idle state to a new function named pnv_cpu_offline() in powernv/idle.c. The rationale behind this code movement is that the data required to determine the deepest available platform state resides in powernv/idle.c. Reviewed-by: Nicholas Piggin Signed-off-by: Gautham R. Shenoy Signed-off-by: Michael Ellerman

powernv: Pass PSSCR value and mask to power9_idle_stop

2017-01-30T21:32:13+00:00

The power9_idle_stop method currently takes only the requested stop level as a parameter and picks up the rest of the PSSCR bits from a hand-coded macro. This is not a very flexible design, especially when the firmware has the capability to communicate the psscr value and the mask associated with a particular stop state via device tree. This patch modifies the power9_idle_stop API to take as parameters the PSSCR value and the PSSCR mask corresponding to the stop state that needs to be set. These PSSCR value and mask are respectively obtained by parsing the "ibm,cpu-idle-state-psscr" and "ibm,cpu-idle-state-psscr-mask" fields from the device tree. In addition to this, the patch adds support for handling stop states for which ESL and EC bits in the PSSCR are zero. As per the architecture, a wakeup from these stop states resumes execution from the subsequent instruction as opposed to waking up at the System Vector. The older firmware sets only the Requested Level (RL) field in the psscr and psscr-mask exposed in the device tree. For older firmware where psscr-mask=0xf, this patch will set the default sane values that the set for for remaining PSSCR fields (i.e PSLL, MTL, ESL, EC, and TR). For the new firmware, the patch will validate that the invariants required by the ISA for the psscr values are maintained by the firmware. This skiboot patch that exports fully populated PSSCR values and the mask for all the stop states can be found here: https://lists.ozlabs.org/pipermail/skiboot/2016-September/004869.html [Optimize the number of instructions before entering STOP with ESL=EC=0, validate the PSSCR values provided by the firimware maintains the invariants required as per the ISA suggested by Balbir Singh] Acked-by: Balbir Singh Signed-off-by: Gautham R. Shenoy Signed-off-by: Michael Ellerman

powerpc/powernv: Use deepest stop state when cpu is offlined

2016-07-15T10:18:42+00:00

If hardware supports stop state, use the deepest stop state when the cpu is offlined. Reviewed-by: Gautham R. Shenoy Signed-off-by: Shreyas B. Prabhu Signed-off-by: Michael Ellerman

powerpc/powernv: move dma_get_required_mask from pnv_phb to pci_controller_ops

2015-08-18T09:32:11+00:00

Simplify the dma_get_required_mask call chain by moving it from pnv_phb to pci_controller_ops, similar to commit 763d2d8df1ee ("powerpc/powernv: Move dma_set_mask from pnv_phb to pci_controller_ops"). Previous call chain: 0) call dma_get_required_mask() (kernel/dma.c) 1) call ppc_md.dma_get_required_mask, if it exists. On powernv, that points to pnv_dma_get_required_mask() (platforms/powernv/setup.c) 2) device is PCI, therefore call pnv_pci_dma_get_required_mask() (platforms/powernv/pci.c) 3) call phb->dma_get_required_mask if it exists 4) it only exists in the ioda case, where it points to pnv_pci_ioda_dma_get_required_mask() (platforms/powernv/pci-ioda.c) New call chain: 0) call dma_get_required_mask() (kernel/dma.c) 1) device is PCI, therefore call pci_controller_ops.dma_get_required_mask if it exists 2) in the ioda case, that points to pnv_pci_ioda_dma_get_required_mask() (platforms/powernv/pci-ioda.c) In the p5ioc2 case, the call chain remains the same - dma_get_required_mask() does not find either a ppc_md call or pci_controller_ops call, so it calls __dma_get_required_mask(). Signed-off-by: Andrew Donnellan Reviewed-by: Daniel Axtens Signed-off-by: Michael Ellerman

powerpc/powernv: Move dma_set_mask() from pnv_phb to pci_controller_ops

2015-06-02T03:18:49+00:00

Previously, dma_set_mask() on powernv was convoluted: 0) Call dma_set_mask() (a/p/kernel/dma.c) 1) In dma_set_mask(), ppc_md.dma_set_mask() exists, so call it. 2) On powernv, that function pointer is pnv_dma_set_mask(). In pnv_dma_set_mask(), the device is pci, so call pnv_pci_dma_set_mask(). 3) In pnv_pci_dma_set_mask(), call pnv_phb->set_dma_mask() if it exists. 4) It only exists in the ioda case, where it points to pnv_pci_ioda_dma_set_mask(), which is the final function. So the call chain is: dma_set_mask() -> pnv_dma_set_mask() -> pnv_pci_dma_set_mask() -> pnv_pci_ioda_dma_set_mask() Both ppc_md and pnv_phb function pointers are used. Rip out the ppc_md call, pnv_dma_set_mask() and pnv_pci_dma_set_mask(). Instead: 0) Call dma_set_mask() (a/p/kernel/dma.c) 1) In dma_set_mask(), the device is pci, and pci_controller_ops.dma_set_mask() exists, so call pci_controller_ops.dma_set_mask() 2) In the ioda case, that points to pnv_pci_ioda_dma_set_mask(). The new call chain is dma_set_mask() -> pnv_pci_ioda_dma_set_mask() Now only the pci_controller_ops function pointer is used. The fallback paths for p5ioc2 are the same. Previously, pnv_pci_dma_set_mask() would find no pnv_phb->set_dma_mask() function, to it would call __set_dma_mask(). Now, dma_set_mask() finds no ppc_md call or pci_controller_ops call, so it calls __set_dma_mask(). Signed-off-by: Daniel Axtens Signed-off-by: Michael Ellerman

powerpc/powernv: Specialise pci_controller_ops for each controller type

2015-06-02T03:18:49+00:00

Remove powernv generic PCI controller operations. Replace it with controller ops for each of the two supported PHBs. As an added bonus, make the two new structs const, which will help guard against bugs such as the one introduced in 65ebf4b63 ("powerpc/powernv: Move controller ops from ppc_md to controller_ops") Signed-off-by: Daniel Axtens Signed-off-by: Michael Ellerman