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2010-12-17ACPI: Execute _PRW for devices reported as inactive or not presentRafael J. Wysocki
If a device is reported as inactive or not present by its _STA control method, acpi_bus_check_add() skips it without evaluating its _PRW method. This leads to a problem when the device's _PRW method points to a GPE, because in that case the GPE may be enabled by ACPICA during the subsequent acpi_update_gpes() call which, in turn, may cause a GPE storm to appear. To avoid this issue, make acpi_bus_check_add() evaluate _PRW for inactive or not present devices and register the wakeup GPE information returned by them, so that acpi_update_gpes() does not enable their GPEs unnecessarily. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-11-13ACPI: debugfs custom_method open to non-rootDave Jones
Currently we have: --w--w--w-. 1 root root 0 2010-11-11 14:56 /sys/kernel/debug/acpi/custom_method which is just crazy. Change this to --w-------. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Len Brown <len.brown@intel.com> Cc: stable@kernel.org (for 2.6.36) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (53 commits) ACPI: install ACPI table handler before any dynamic tables being loaded ACPI / PM: Blacklist another machine that needs acpi_sleep=nonvs ACPI: Page based coalescing of I/O remappings optimization ACPI: Convert simple locking to RCU based locking ACPI: Pre-map 'system event' related register blocks ACPI: Add interfaces for ioremapping/iounmapping ACPI registers ACPI: Maintain a list of ACPI memory mapped I/O remappings ACPI: Fix ioremap size for MMIO reads and writes ACPI / Battery: Return -ENODEV for unknown values in get_property() ACPI / PM: Fix reference counting of power resources Subject: [PATCH] ACPICA: Fix Scope() op in module level code ACPI battery: support percentage battery remaining capacity ACPI: Make Embedded Controller command timeout delay configurable ACPI dock: move some functions to .init.text ACPI: thermal: remove unused limit code ACPI: static sleep_states[] and acpi_gts_bfs_check ACPI: remove dead code ACPI: delete dedicated MAINTAINERS entries for ACPI EC and BATTERY drivers ACPI: Only processor needs CPU_IDLE ACPICA: Update version to 20101013 ...
2010-10-26Merge branch 'idle-release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6 * 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6: intel_idle: do not use the LAPIC timer for ATOM C2 intel_idle: add initial Sandy Bridge support acpi_idle: delete bogus data from cpuidle_state.power_usage intel_idle: delete bogus data from cpuidle_state.power_usage intel_idle: simplify test for leave_mm()
2010-10-26Merge branch 'misc' into releaseLen Brown
2010-10-26Merge branch 'acpi-mmio' into releaseLen Brown
Conflicts: drivers/acpi/osl.c Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-26ACPI: install ACPI table handler before any dynamic tables being loadedZhang Rui
ACPI table sysfs I/F is broken by commit 78f1699659963fff97975df44db6d5dbe7218e55 Author: Alex Chiang <achiang@hp.com> Date: Sun Dec 20 12:19:09 2009 -0700 ACPI: processor: call _PDC early because dynamic SSDT tables may be loaded in _PDC, before installing the ACPI table handler. As a result, the sysfs I/F of these dynamic tables are located at /sys/firmware/acpi/tables instead of /sys/firmware/acpi/tables/dynamic, which is not true. Invoke acpi_sysfs_init() before acpi_early_processor_set_pdc(), so that the table handler is installed before any dynamic tables loaded. https://bugzilla.kernel.org/show_bug.cgi?id=21142 CC: Dennis Jansen <dennis.jansen@web.de> CC: Alex Chiang <achiang@hp.com> Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-25ACPI / PM: Blacklist another machine that needs acpi_sleep=nonvsRafael J. Wysocki
Sony Vaio VPCEB1Z1E is reported to require acpi_sleep=nonvs for suspend/resume to work on it correctly, so blacklist it. Reported-by: Emanuele Bigiarini <pulmro@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-25Merge branch 'ec-param' into releaseLen Brown
2010-10-25Merge branch 'power-refcount' into releaseLen Brown
2010-10-25Merge branch 'cleanup' into releaseLen Brown
2010-10-25Merge branch 'gpe-defer' into releaseLen Brown
2010-10-25Merge branch 'battery' into releaseLen Brown
2010-10-25Merge branch 'acpi_pm_device_sleep_state' into releaseLen Brown
2010-10-25Merge branches 'bugzilla-15807', 'bugzilla-15979-v2' and 'bugzilla-19162' ↵Len Brown
into release
2010-10-25Merge branch 'procfs-cleanup-v2' into releaseLen Brown
2010-10-25Merge branch 'acpica' into releaseLen Brown
Conflicts: drivers/acpi/acpica/aclocal.h Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-24ACPI: Page based coalescing of I/O remappings optimizationMyron Stowe
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 15651291a2f8c11e7e6a42d8bfde7a213ff13262 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>
2010-10-24ACPI: Convert simple locking to RCU based lockingMyron Stowe
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>
2010-10-24ACPI: Pre-map 'system event' related register blocksMyron Stowe
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>
2010-10-24ACPI: Add interfaces for ioremapping/iounmapping ACPI registersMyron Stowe
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>
2010-10-24ACPI: Maintain a list of ACPI memory mapped I/O remappingsMyron Stowe
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>
2010-10-24ACPI: Fix ioremap size for MMIO reads and writesMyron Stowe
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>
2010-10-23ACPI / Battery: Return -ENODEV for unknown values in get_property()Rafael J. Wysocki
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>
2010-10-23ACPI / PM: Fix reference counting of power resourcesRafael J. Wysocki
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>
2010-10-23Subject: [PATCH] ACPICA: Fix Scope() op in module level codeBob Moore
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>
2010-10-22Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: vfs: make no_llseek the default vfs: don't use BKL in default_llseek llseek: automatically add .llseek fop libfs: use generic_file_llseek for simple_attr mac80211: disallow seeks in minstrel debug code lirc: make chardev nonseekable viotape: use noop_llseek raw: use explicit llseek file operations ibmasmfs: use generic_file_llseek spufs: use llseek in all file operations arm/omap: use generic_file_llseek in iommu_debug lkdtm: use generic_file_llseek in debugfs net/wireless: use generic_file_llseek in debugfs drm: use noop_llseek
2010-10-22ACPI battery: support percentage battery remaining capacityZhang Rui
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>
2010-10-22ACPI: Make Embedded Controller command timeout delay configurableThomas Renninger
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>
2010-10-21Merge branch 'x86-idle-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-idle-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, hotplug: In the MWAIT case of play_dead, CLFLUSH the cache line x86, hotplug: Move WBINVD back outside the play_dead loop x86, hotplug: Use mwait to offline a processor, fix the legacy case x86, mwait: Move mwait constants to a common header file
2010-10-19ACPI dock: move some functions to .init.textUwe Kleine-König
find_dock and find_bay are only called by dock_init which lives in .init.text dock_add is only called by find_dock and find_bay. So all three functions can be moved to .init.text, too. This fixes: WARNING: vmlinux.o(.text+0x2134b7): Section mismatch in reference from the function dock_add() to the function .init.text:platform_device_register_resndata() The function dock_add() references the function __init platform_device_register_resndata(). This is often because dock_add lacks a __init annotation or the annotation of platform_device_register_resndata is wrong. for a build with unset CONFIG_MODULES. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-19ACPI: thermal: remove unused limit codeLen Brown
acpi_processor_apply_limit() acpi_thermal_cpufreq_increase() acpi_thermal_cpufreq_decrease() Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-19ACPI: static sleep_states[] and acpi_gts_bfs_checkStephen Hemminger
Only used in one file so should be static. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-19ACPI: remove dead codeStephen Hemminger
Found by running make namespacecheck on linux-next Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-19ACPI: Only processor needs CPU_IDLEJean Delvare
ACPI support itself doesn't need CPU_IDLE, only ACPI_PROCESSOR does, so only ACPI_PROCESSOR should select CPU_IDLE. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-17ACPICA: Clear PCIEXP_WAKE_STS when clearing ACPI eventsColin Ian King
When clearing status bits via acpi_hw_clear_acpi_status, also clear the PCIEXP_WAKE_STS bit. Original change from Colin King. ACPICA BZ 880. http://www.acpica.org/bugzilla/show_bug.cgi?id=880 http://bugs.launchpad.net/bugs/613381 Signed-off-by: Colin Ian King <colin.king@canonical.com> 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>
2010-10-17ACPICA: Add Vista SP2 to supported _OSI stringsBob Moore
Added "Windows 2006 SP2" for Vista SP2. 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>
2010-10-17ACPICA: Eliminate duplicate code in acpi_ut_execute_* functionsBob Moore
Now that the nsrepair code automatically repairs _HID-related strings, this type of code is no longer needed in acpi_ut_execute_HID, acpi_ut_execute_CID, and acpi_ut_execute_UID. ACPICA BZ 878. http://www.acpica.org/bugzilla/show_bug.cgi?id=878 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>
2010-10-17ACPICA: Change type of _TZ from ThermalZone to DeviceBob Moore
The type of ThermalZone was confusing hosts as they process the various ThermalZone objects. ACPICA BZ 876. http://www.acpica.org/bugzilla/show_bug.cgi?id=876 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>
2010-10-17ACPICA: Comment update; no functional changeBob Moore
Add a usage note to InstallAddressSpaceHandler. 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>
2010-10-15ACPI: remove unused declaration of proc_fs.hZhang Rui
Remove unused declaration of proc_fs.h. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-15ACPI processor: make /proc/acpi/processor/*/throttle depends on ↵Zhang Rui
CONFIG_ACPI_PROCFS As a feature that would only be used when system is overheating, the processor t-state control should not be exported to user space. Make /proc/acpi/processor/*/throttle depends on CONFIG_ACPI_PROCFS, which is cleared by default. And we will remove this I/F in 2.6.38. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-15ACPI video: remove deprecated procfs I/FZhang Rui
Remove the deprecated ACPI video driver procfs I/F, as stated in the changelog of commit 6e37c658aefa57c472b2dbf1de88dbd3c67cdb52 New sysfs I/F is available at /sys/class/backlight/ Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-15ACPI thermal: remove deprecated procfs I/FZhang Rui
Remove the deprecated ACPI thermal driver procfs I/F, as stated in the changelog of commit 43d9f87b79804f2d75d9d8a81c862b179f055a15 sysfs I/F is available at /sys/class/thermal/thermal_zoneX/ Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-15ACPI fan: remove deprecated procfs I/FZhang Rui
Remove deprecated ACPI Fan driver procfs interface. The ACPI fan driver (CONFIG_ACPI_FAN) selects the generic thermal sysfs driver (CONFIG_THERMAL) since 2.6.26, so new sysfs I/F is available at /sys/class/thermal/cooling_devicecX/ Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-15ACPI ac/battery/sbs: sysfs I/F always built in, procfs I/F disabled by defaultZhang Rui
ACPI AC/Battery/SBS driver has different kernel option for procfs and sysfs I/F. This patch, 1. Change CONFIG_ACPI_PROCFS_POWER to 'n' by default so that we can remove it in the next release or two. 2. Remove CONFIG_ACPI_SYSFS_POWER and always build in the sysfs I/F of these drivers. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-15ACPI: add FW_BUG to OSI(Linux) messageLen Brown
Linux-2.6.22 initiated a dmesg complaint when it saw BIOS that invoked OSI(Linux). Linux-2.6.23 continued that complaint and started our policy of ignoring the bogus BIOS request. Past-time for Linux to label that complaint with FW_BUG. Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-15acpi_idle: delete bogus data from cpuidle_state.power_usageLen Brown
The mW data in this field comes from AML _CST, which was typed in by a BIOS writer, and is thus considered unreliable. Linux does not use it for making any decisions. We do display it in sysfs where somebody might read it and assume it is meaningful, so delete it. Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-15ACPI / PM: Fix problems with acpi_pm_device_sleep_state()Rafael J. Wysocki
There is a number of problems with acpi_pm_device_sleep_state() now. First, if _S0W is not defined, it prevents devices from being put into D3 by PCI runtime PM, which shouldn't happen. Second, it shouldn't use adev->wakeup.state.enabled, because if it's set, it only means that either the device is permanently enabled to wake up the system, or that it has been enabled to do that through /proc/acpi/wakeup. Finally, it should be compiled if CONFIG_PM_SLEEP is not set, so that PCI runtime PM works correctly in that case. Fix these problems. Reported-by: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>