kernel/linux.git/drivers/acpi/processor_pdc.c, branch v6.1.168

ACPI: processor: Fix evaluating _PDC method when running as Xen dom0

2023-05-11T14:03:11+00:00

[ Upstream commit 073828e954459b883f23e53999d31e4c55ab9654 ] In ACPI systems, the OS can direct power management, as opposed to the firmware. This OS-directed Power Management is called OSPM. Part of telling the firmware that the OS going to direct power management is making ACPI "_PDC" (Processor Driver Capabilities) calls. These _PDC methods must be evaluated for every processor object. If these _PDC calls are not completed for every processor it can lead to inconsistency and later failures in things like the CPU frequency driver. In a Xen system, the dom0 kernel is responsible for system-wide power management. The dom0 kernel is in charge of OSPM. However, the number of CPUs available to dom0 can be different than the number of CPUs physically present on the system. This leads to a problem: the dom0 kernel needs to evaluate _PDC for all the processors, but it can't always see them. In dom0 kernels, ignore the existing ACPI method for determining if a processor is physically present because it might not be accurate. Instead, ask the hypervisor for this information. Fix this by introducing a custom function to use when running as Xen dom0 in order to check whether a processor object matches a CPU that's online. Such checking is done using the existing information fetched by the Xen pCPU subsystem, extending it to also store the ACPI ID. This ensures that _PDC method gets evaluated for all physically online CPUs, regardless of the number of CPUs made available to dom0. Fixes: 5d554a7bb064 ("ACPI: processor: add internal processor_physically_present()") Signed-off-by: Roger Pau Monné Reviewed-by: Juergen Gross Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: processor: Get rid of ACPICA message printing

2021-03-08T15:51:19+00:00

The ACPI_DEBUG_PRINT() and ACPI_EXCEPTION() macros are used for message printing in the ACPICA code and they should not be used elsewhere. Special configuration (either kernel command line or sysfs-based) is needed to see the messages printed by them and the format of those messages is also special and convoluted. For this reason, replace all of the ACPI_DEBUG_PRINT() and ACPI_EXCEPTION() instances in the ACPI processor driver with corresponding dev_*(), acpi_handle_*() and pr_*() calls depending on the context in which they appear. Also drop the ACPI_PROCESSOR_COMPONENT definition that is not going to be necessary any more. Signed-off-by: Rafael J. Wysocki Reviewed-by: Hanjun Guo

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

dmi: Mark all struct dmi_system_id instances const

2017-09-14T09:59:30+00:00

... and __initconst if applicable. Based on similar work for an older kernel in the Grsecurity patch. [JD: fix toshiba-wmi build] [JD: add htcpen] [JD: move __initconst where checkscript wants it] Signed-off-by: Christoph Hellwig Signed-off-by: Jean Delvare

ACPI / processor: Introduce invalid_logical_cpuid()

2015-05-13T21:28:14+00:00

In ACPI processor drivers, we use direct comparisons of cpu logical id with -1 which are error prone in case logical cpuid is accidentally assinged an error code and prevents us from returning an error-encoding cpuid directly in some cases. So introduce invalid_logical_cpuid() to identify cpu with invalid logical cpu num, then it will be used to replace the direct comparisons with -1. Signed-off-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki

ACPI / processor: Introduce ARCH_MIGHT_HAVE_ACPI_PDC

2014-07-21T11:50:58+00:00

The use of _PDC is deprecated in ACPI 3.0 in favor of _OSC, as ARM platform is supported only in ACPI 5.0 or higher version, _PDC will not be used in ARM platform, so make Make _PDC only for platforms with Intel CPUs. Introduce ARCH_MIGHT_HAVE_ACPI_PDC and move _PDC related code in ACPI processor driver into a single file processor_pdc.c, make x86 and ia64 select it when ACPI is enabled. This patch also use pr_* to replace printk to fix the checkpatch warning and factor acpi_processor_alloc_pdc() a little bit to avoid duplicate pr_err() code. Suggested-by: Robert Richter Signed-off-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki

ACPI: processor: mv processor_pdc.c processor_core.c

2010-03-15T01:17:17+00:00

We've renamed the old processor_core.c to processor_driver.c, to convey the idea that it can be built modular and has driver-like bits. Now let's re-create a processor_core.c for the bits needed statically by the rest of the kernel. The contents of processor_pdc.c are a good starting spot, so let's just rename that file and complete our three card monte. Acked-by: Venkatesh Pallipadi Signed-off-by: Alex Chiang Signed-off-by: Len Brown

ACPI: processor: only evaluate _PDC once per processor

2010-01-22T17:39:56+00:00

If we evaluate _PDC in the early path, we do not want to evaluate it again when the processor driver is loaded. Cc: Venkatesh Pallipadi Signed-off-by: Alex Chiang Signed-off-by: Len Brown

ACPI: processor: add kernel command line support for early _PDC eval

2010-01-22T17:39:21+00:00

Allow platforms not listed in DMI table to opt-in and evaluate _PDC early. Signed-off-by: Alex Chiang Signed-off-by: Len Brown

Merge branch 'bugzilla-14954' into release

2010-01-20T06:26:22+00:00