kernel/linux.git/drivers/xen/pcpu.c, branch v6.12.80

xen: pcpu: make xen_pcpu_subsys const

2024-02-13T08:03:31+00:00

Now that the driver core can properly handle constant struct bus_type, move the xen_pcpu_subsys variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman Suggested-by: Greg Kroah-Hartman Signed-off-by: Ricardo B. Marliere Reviewed-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20240203-bus_cleanup-xen-v1-1-c2f5fe89ed95@marliere.net Signed-off-by: Juergen Gross

acpi/processor: sanitize _OSC/_PDC capabilities for Xen dom0

2023-11-13T06:22:00+00:00

The Processor capability bits notify ACPI of the OS capabilities, and so ACPI can adjust the return of other Processor methods taking the OS capabilities into account. When Linux is running as a Xen dom0, the hypervisor is the entity in charge of processor power management, and hence Xen needs to make sure the capabilities reported by _OSC/_PDC match the capabilities of the driver in Xen. Introduce a small helper to sanitize the buffer when running as Xen dom0. When Xen supports HWP, this serves as the equivalent of commit a21211672c9a ("ACPI / processor: Request native thermal interrupt handling via _OSC") to avoid SMM crashes. Xen will set bit ACPI_PROC_CAP_COLLAB_PROC_PERF (bit 12) in the capability bits and the _OSC/_PDC call will apply it. [ jandryuk: Mention Xen HWP's need. Support _OSC & _PDC ] Signed-off-by: Roger Pau Monné Cc: stable@vger.kernel.org Signed-off-by: Jason Andryuk Reviewed-by: Michal Wilczynski Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20231108212517.72279-1-jandryuk@gmail.com Signed-off-by: Juergen Gross

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

2023-03-22T18:36:31+00:00

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

xen/pcpu: fix possible memory leak in register_pcpu()

2022-11-14T12:29:07+00:00

In device_add(), dev_set_name() is called to allocate name, if it returns error, the name need be freed. As comment of device_register() says, it should use put_device() to give up the reference in the error path. So fix this by calling put_device(), then the name can be freed in kobject_cleanup(). Fixes: f65c9bb3fb72 ("xen/pcpu: Xen physical cpus online/offline sys interface") Signed-off-by: Yang Yingliang Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20221110152441.401630-1-yangyingliang@huawei.com Signed-off-by: Juergen Gross

xen: Use DEVICE_ATTR_*() macro

2021-07-05T07:23:31+00:00

Use DEVICE_ATTR_*() helper instead of plain DEVICE_ATTR(), which makes the code a bit shorter and easier to read. Signed-off-by: YueHaibing Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20210526141019.13752-1-yuehaibing@huawei.com Signed-off-by: Juergen Gross

xen: Remove support for PV ACPI cpu/memory hotplug

2021-04-23T07:31:50+00:00

Commit 76fc253723ad ("xen/acpi-stub: Disable it b/c the acpi_processor_add is no longer called.") declared as BROKEN support for Xen ACPI stub (which is required for xen-acpi-{cpu|memory}-hotplug) and suggested that this is temporary and will be soon fixed. This was in March 2013. Further, commit cfafae940381 ("xen: rename dom0_op to platform_op") renamed an interface used by memory hotplug code without updating that code (as it was BROKEN and therefore not compiled). This was in November 2015 and has gone unnoticed for over 5 year. It is now clear that this code is of no interest to anyone and therefore should be removed. Signed-off-by: Boris Ostrovsky Acked-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/1618336344-3162-1-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Juergen Gross

xen: rename dom0_op to platform_op

2015-12-21T14:40:55+00:00

The dom0_op hypercall has been renamed to platform_op since Xen 3.2, which is ancient, and modern upstream Linux kernels cannot run as dom0 and it anymore anyway. Signed-off-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky

xen: pcpu: Use static attribute groups for sysfs entry

2015-03-16T14:49:13+00:00

Instead of manual calls of device_create_file() and device_remove_file(), assign the static attribute groups to the device to register. The conditional build of sysfs is done in is_visible callback instead. Signed-off-by: Takashi Iwai Signed-off-by: David Vrabel

drivers: xen: Include appropriate header file in pcpu.c

2014-02-28T20:26:08+00:00

Include appropriate header file in xen/pcpu.c because include/xen/acpi.h contains prototype declaration of functions defined in the file. This eliminates the following warning in xen/pcpu.c: drivers/xen/pcpu.c:336:6: warning: no previous prototype for ‘xen_pcpu_hotplug_sync’ [-Wmissing-prototypes] drivers/xen/pcpu.c:346:5: warning: no previous prototype for ‘xen_pcpu_id’ [-Wmissing-prototypes] Signed-off-by: Rashika Kheria Reviewed-by: Josh Triplett Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: David Vrabel

xen: Convert printks to pr_

2013-06-28T15:19:58+00:00

Convert printks to pr_ (excludes printk(KERN_DEBUG...) to be more consistent throughout the xen subsystem. Add pr_fmt with KBUILD_MODNAME or "xen:" KBUILD_MODNAME Coalesce formats and add missing word spaces Add missing newlines Align arguments and reflow to 80 columns Remove DRV_NAME from formats as pr_fmt adds the same content This does change some of the prefixes of these messages but it also does make them more consistent. Signed-off-by: Joe Perches Signed-off-by: Konrad Rzeszutek Wilk