kernel/git/stable/linux.git/drivers/acpi/scan.c, branch linux-4.8.y

ACPI / drivers: replace acpi_probe_lock spinlock with mutex

2016-09-02T20:22:21+00:00

Commit e647b532275b ("ACPI: Add early device probing infrastructure") introduced code that allows inserting driver specific struct acpi_probe_entry probe entries into ACPI linker sections (one per-subsystem, eg irqchip, clocksource) that are then walked to retrieve the data and function hooks required to probe the respective kernel components. Probing for all entries in a section is triggered through the __acpi_probe_device_table() function, that in turn, according to the table ID a given probe entry reports parses the table with the function retrieved from the respective section structures (ie struct acpi_probe_entry). Owing to the current ACPI table parsing implementation, the __acpi_probe_device_table() function has to share global variables with the acpi_match_madt() function, so in order to guarantee mutual exclusion locking is required between the two functions. Current kernel code implements the locking through the acpi_probe_lock spinlock; this has the side effect of requiring all code called within the lock (ie struct acpi_probe_entry.probe_{table/subtbl} hooks) not to sleep. However, kernel subsystems that make use of the early probing infrastructure are relying on kernel APIs that may sleep (eg irq_domain_alloc_fwnode(), among others) in the function calls pointed at by struct acpi_probe_entry.{probe_table/subtbl} entries (eg gic_v2_acpi_init()), which is a bug. Since __acpi_probe_device_table() is called from context that is allowed to sleep the acpi_probe_lock spinlock can be replaced with a mutex; this fixes the issue whilst still guaranteeing mutual exclusion. Signed-off-by: Lorenzo Pieralisi Fixes: e647b532275b (ACPI: Add early device probing infrastructure) Cc: 4.4+ # 4.4+ Signed-off-by: Rafael J. Wysocki

Merge tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2016-07-27T18:35:37+00:00

Pull xen updates from David Vrabel: "Features and fixes for 4.8-rc0: - ACPI support for guests on ARM platforms. - Generic steal time support for arm and x86. - Support cases where kernel cpu is not Xen VCPU number (e.g., if in-guest kexec is used). - Use the system workqueue instead of a custom workqueue in various places" * tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (47 commits) xen: add static initialization of steal_clock op to xen_time_ops xen/pvhvm: run xen_vcpu_setup() for the boot CPU xen/evtchn: use xen_vcpu_id mapping xen/events: fifo: use xen_vcpu_id mapping xen/events: use xen_vcpu_id mapping in events_base x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to shared_info x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_op xen: introduce xen_vcpu_id mapping x86/acpi: store ACPI ids from MADT for future usage x86/xen: update cpuid.h from Xen-4.7 xen/evtchn: add IOCTL_EVTCHN_RESTRICT xen-blkback: really don't leak mode property xen-blkback: constify instance of "struct attribute_group" xen-blkfront: prefer xenbus_scanf() over xenbus_gather() xen-blkback: prefer xenbus_scanf() over xenbus_gather() xen: support runqueue steal time on xen arm/xen: add support for vm_assist hypercall xen: update xen headers xen-pciback: drop superfluous variables xen-pciback: short-circuit read path used for merging write values ...

ACPI: add support for ACPI reconfiguration notifiers

2016-07-08T19:52:35+00:00

Add support for ACPI reconfiguration notifiers to allow subsystems to react to changes in the ACPI tables that happen after the initial enumeration. This is similar with the way dynamic device tree notifications work. The reconfigure notifications supported for now are device add and device remove. Since ACPICA allows only one table notification handler, this patch makes the table notifier function generic and moves it out of the sysfs specific code. Signed-off-by: Octavian Purdila Reviewed-by: Mika Westerberg Signed-off-by: Rafael J. Wysocki

ACPI / scan: fix enumeration (visited) flags for bus rescans

2016-07-08T19:52:34+00:00

If the ACPI tables change as a result of a dinamically loaded table and a bus rescan is required the enumeration/visited flag are not consistent. I2C/SPI are not directly enumerated in acpi_bus_attach(), however the visited flag is set. This makes it impossible to check if an ACPI device has already been enumerated by the I2C and SPI subsystems. To fix this issue we only set the visited flags if the device is not I2C or SPI. With this change we also need to remove setting visited to false from acpi_bus_attach(), otherwise if we rescan already enumerated I2C/SPI devices we try to re-enumerate them. Note that I2C/SPI devices can be enumerated either via a scan handler (when using PRP0001) or via regular device_attach(). In either case the flow goes through acpi_default_enumeration() which makes it the ideal place to mark the ACPI device as enumerated. Signed-off-by: Octavian Purdila Reviewed-by: Mika Westerberg Signed-off-by: Rafael J. Wysocki

Xen: ACPI: Hide UART used by Xen

2016-07-06T09:34:41+00:00

ACPI 6.0 introduces a new table STAO to list the devices which are used by Xen and can't be used by Dom0. On Xen virtual platforms, the physical UART is used by Xen. So here it hides UART from Dom0. CC: "Rafael J. Wysocki" (supporter:ACPI) CC: Len Brown (supporter:ACPI) CC: linux-acpi@vger.kernel.org (open list:ACPI) Signed-off-by: Shannon Zhao Acked-by: Rafael J. Wysocki

ACPI / scan: AMBA bus probing support

2016-02-16T18:58:25+00:00

On ARM64 some devices use the AMBA device and not the platform bus for probing so add support for this. Uses a dummy clock for apb_pclk as ACPI does not have a suitable clock representation and to keep the core AMBA bus code unchanged between probing methods. Acked-by: Russell King Signed-off-by: Graeme Gregory Signed-off-by: Aleksey Makarov Signed-off-by: Rafael J. Wysocki

ACPI / utils: Add acpi_dev_present()

2015-12-09T00:31:41+00:00

There's an idiom in use by 7 Linux drivers to detect the presence of a particular ACPI HID by walking the namespace with acpi_get_devices(). The callback passed to acpi_get_devices() is mostly identical across the drivers, leading to lots of duplicate code. Add acpi_dev_present(), the ACPI equivalent to pci_dev_present(), allowing us to deduplicate all that boilerplate in the drivers. Signed-off-by: Lukas Wunner Reviewed-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki

ACPI / scan: Fix acpi_bus_id_list bookkeeping

2015-12-09T00:30:26+00:00

acpi_device_add() allocates and adds an element to acpi_bus_id_list (or increments the instance count if the device's HID is already present in the list), but the element is never deleted from the list nor freed. Fix it. Signed-off-by: Lukas Wunner Signed-off-by: Rafael J. Wysocki

ACPI / scan: set status to 0 if _STA failed

2015-11-30T14:06:16+00:00

Some ACPI node's _STA will touch operation region field, since the evaluation of _STA in acpi_bus_type_and_status is very early, the operation region handler is not ready yet. Instead of fail that function and not creating the acpi_device node consequently, set status to 0 so that later when the driver for that device is probing, it can find the acpi_device node and proceed normally. And at that time, the handler for the operation region is ready and its _STA evaluation will succeed, its present status can be checked there. Even there will be no driver using this node later, it doesn't seem hurt to have one more acpi_device node created with status set to 0. This happens on Microsoft Surface 3, where the SPI device node NTRG's _STA touches GPIO fields and the SPI core driver will only enumerate SPI devices from ACPI if the acpi_device node is 1: created; 2: _STA indicates it's present. Note that due to another problem in SPI driver, for NTRG to be actually enumerated, some changes have to be made in the SPI layer, which is addressed by Mika(not send out yet): https://bugzilla.kernel.org/show_bug.cgi?id=104291#c23 Link: https://bugzilla.kernel.org/show_bug.cgi?id=104291 Reported-by: Bastien Nocera Signed-off-by: Aaron Lu Reviewed-by: Mika Westerberg Signed-off-by: Rafael J. Wysocki

Merge branch 'acpi-pci'

2015-11-07T00:30:10+00:00

* acpi-pci: PCI: ACPI: Add support for PCI device DMA coherency PCI: OF: Move of_pci_dma_configure() to pci_dma_configure() of/pci: Fix pci_get_host_bridge_device leak device property: ACPI: Remove unused DMA APIs device property: ACPI: Make use of the new DMA Attribute APIs device property: Adding DMA Attribute APIs for Generic Devices ACPI: Adding DMA Attribute APIs for ACPI Device device property: Introducing enum dev_dma_attr ACPI: Honor ACPI _CCA attribute setting Conflicts: drivers/crypto/ccp/ccp-platform.c