This patch optimizes ACPI MMIO remappings by keeping track of the
remappings on a PAGE_SIZE granularity.
When an ioremap() occurs, the underlying infrastructure works on a 'page'
based granularity. As such, an ioremap() request for 1 byte for example,
will end up mapping in an entire (PAGE_SIZE) page. Huang Ying took
advantage of this in commit 15651291a2 by
checking if subsequent ioremap() requests reside within any of the list's
existing remappings still in place, and if so, incrementing a reference
count on the existing mapping as opposed to performing another ioremap().
Signed-off-by: Myron Stowe <myron.stowe@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Convert the simple locking introduced earlier for the ACPI MMIO
remappings list to an RCU based locking scheme.
Signed-off-by: Myron Stowe <myron.stowe@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
During ACPI initialization, pre-map fixed hardware registers that are
accessed during ACPI's 'system event' related IRQ handing.
ACPI's 'system event' handing accesses specific fixed hardware
registers; namely PM1a event, PM1b event, GPE0, and GPE1 register
blocks which are declared within the FADT. If these registers are
backed by MMIO, as opposed to I/O port space, accessing them within
interrupt context will cause a panic as acpi_os_read_memory()
depends on ioremap() in such cases - BZ 18012.
By utilizing the functionality provided in the previous two patches -
ACPI: Maintain a list of ACPI memory mapped I/O remappings, and, ACPI:
Add interfaces for ioremapping/iounmapping ACPI registers - accesses
to ACPI MMIO areas will now be safe from within interrupt contexts (IRQ
and/or NMI) provided the area was pre-mapped. This solves BZ 18012.
ACPI "System Event" reference(s):
ACPI Specification, Revision 4.0, Section 3 "ACPI Overview",
3.8 "System Events", 5.6 "ACPI Event Programming Model".
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=18012
Reported-by: <bjorn.helgaas@hp.com>
Signed-off-by: Myron Stowe <myron.stowe@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add remapping and unmapping interfaces for ACPI registers that are
backed by memory mapped I/O (MMIO). These interfaces, along with
the MMIO remapping list, enable accesses of such registers from within
interrupt context.
ACPI Generic Address Structure (GAS) reference (ACPI's fixed/generic
hardware registers use the GAS format):
ACPI Specification, Revision 4.0, Section 5.2.3.1, "Generic Address
Structure".
Signed-off-by: Myron Stowe <myron.stowe@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
For memory mapped I/O (MMIO) remappings, add a list to maintain the
remappings and augment the corresponding mapping and unmapping interface
routines (acpi_os_map_memory() and acpi_os_unmap_memory()) to
dynamically add to, and delete from, the list.
The current ACPI I/O accessing methods - acpi_read() and acpi_write() -
end up calling ioremap() when accessing MMIO. This prevents use of these
methods within interrupt context (IRQ and/or NMI), since ioremap() may
block to allocate memory. Maintaining a list of MMIO remappings enables
accesses to such areas from within interrupt context provided they have
been pre-mapped.
Signed-off-by: Myron Stowe <myron.stowe@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The size used for I/O remapping MMIO read and write accesses has not
accounted for the basis of ACPI's Generic Address Structure (GAS)
'Register Bit Width' field which is bits, not bytes. This patch
adjusts the ioremap() 'size' argument accordingly.
ACPI "Generic Register" reference:
ACPI Specification, Revision 4.0, Section 5.2.3.1, "Generic Address
Structure".
Signed-off-by: Myron Stowe <myron.stowe@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The function acpi_battery_get_property() is called by the
power supply framework's function power_supply_show_property()
implementing the sysfs interface for power supply devices as the
ACPI battery driver's ->get_property() callback. Thus it is supposed
to return error code if the value of the given property is unknown.
Unfortunately, however, it returns 0 in those cases and puts a
wrong (negative) value into the intval field of the
union power_supply_propval object provided by
power_supply_show_property(). In consequence, wrong negative
values are read by user space from the battery's sysfs files.
Fix this by making acpi_battery_get_property() return -ENODEV
for properties with unknown values (-ENODEV is returned, because
power_supply_uevent() returns with error for any other error code
returned by power_supply_show_property()).
Reported-and-tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
The reference counting of ACPI power resources is currently broken
for a few reasons. First, instead of using a simple reference
counter per power resource it uses a list of objects representing
refereces to the given power resource from devices. This leads to
the second breakage, because it prevents power resources from
being referenced more than once by one device, which is necessary
if the device is configured to signal wakeup. Namely, when putting
the device into a low power state we first call
acpi_enable_wakeup_device_power() that should reference count power
resources needed for signaling wakeup and then we call
acpi_power_transition() to power off the device. The latter call
drops references to the device's power resources, possibly including
the ones added by acpi_enable_wakeup_device_power(), so the device
can't signal wakeup as a result. Apart from this, the locking
in acpi_power_on() and acpi_power_off_device() doesn't prevent
all possible races from happening, which may be problematic for
runtime PM and asynchronous suspend and resume.
Fix the problem by using a counter for power resources reference
counting and putting the evaluation of ACPI _ON and _OFF methods
under the power resource mutex.
Reported-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Some Panasonic Toughbooks create nodes in module level code.
Module level code is the executable AML code outside of control method,
for example, below AML code creates a node \_SB.PCI0.GFX0.DD02.CUBL
If (\_OSI ("Windows 2006"))
{
Scope (\_SB.PCI0.GFX0.DD02)
{
Name (CUBL, Ones)
...
}
}
Scope() op does not actually create a new object, it refers to an
existing object(\_SB.PCI0.GFX0.DD02 in above example). However, for
Scope(), we want to indeed open a new scope, so the child nodes(CUBL in
above example) can be created correctly under it.
https://bugzilla.kernel.org/show_bug.cgi?id=19462
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
According to the ACPI spec, some kinds of primary battery can
report percentage battery remaining capacity directly to OS.
In this case, it reports the LastFullChargedCapacity == 100,
BatteryPresentRate = 0xFFFFFFFF, and BatteryRemaingCapacity a
percentage value, which actually means RemainingBatteryPercentage.
Now we found some battery follows this rule even if it's a rechargeable.
https://bugzilla.kernel.org/show_bug.cgi?id=15979
Handle these batteries correctly in ACPI battery driver
so that they won't break userspace.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Here and then there show up machines which need higher timeout values.
Finding this on affected machines can be cumbersome, because
ACPI_EC_DELAY is a compile option -> make it configurable via boot param.
This can even be provided writable at runtime via:
/sys/modules/acpi/parameters/ec_delay
Known machines where this helps:
Some HP machines where for whatever reasons specific EC accesses take
very long at resume from S3 (in _WAK function).
The AE_TIME error is passed upwards and the ACPI interpreter will
not execute the rest of the _WAK function which results in not properly
initialized devices/variables with different side-effects.
Afaik, on some MSI machines this helped as well.
If this param is needed there probably are underlying problems like:
- EC firmware bug
- A kernel EC driver bug
- An ACPI interpreter behavior (e.g. timings when specific
EC accesses happen and how) which the EC does not like
- ...
which should get evaluated further, but often are nasty or
impossible to fix from OS side.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus:
MIPS: O32 compat/N32: Fix to use compat syscall wrappers for AIO syscalls.
MAINTAINERS: Change list for ioc_serial to linux-serial.
SERIAL: ioc3_serial: Return -ENOMEM on memory allocation failure
MIPS: jz4740: Fix Kbuild Platform file.
MIPS: Repair Kbuild make clean breakage.
Len Brown
Myron Stowe
Rafael J. Wysocki
Bob Moore
Zhang Rui
Thomas Renninger
Linus Torvalds