diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/gpio.txt | 17 | ||||
| -rw-r--r-- | Documentation/hrtimer/timer_stats.txt | 68 | ||||
| -rw-r--r-- | Documentation/hrtimers/highres.txt | 249 | ||||
| -rw-r--r-- | Documentation/hrtimers/hrtimers.txt (renamed from Documentation/hrtimers.txt) | 0 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-i801 | 60 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-parport | 15 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-piix4 | 2 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-viapro | 7 | ||||
| -rw-r--r-- | Documentation/i2c/porting-clients | 6 | ||||
| -rw-r--r-- | Documentation/i2c/smbus-protocol | 2 | ||||
| -rw-r--r-- | Documentation/i2c/writing-clients | 58 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 16 | ||||
| -rw-r--r-- | Documentation/powerpc/booting-without-of.txt | 4 | ||||
| -rw-r--r-- | Documentation/powerpc/mpc52xx-device-tree-bindings.txt | 183 | ||||
| -rw-r--r-- | Documentation/x86_64/boot-options.txt | 132 | ||||
| -rw-r--r-- | Documentation/x86_64/cpu-hotplug-spec | 2 | ||||
| -rw-r--r-- | Documentation/x86_64/kernel-stacks | 26 | ||||
| -rw-r--r-- | Documentation/x86_64/machinecheck | 70 | ||||
| -rw-r--r-- | Documentation/x86_64/mm.txt | 22 |
19 files changed, 780 insertions, 159 deletions
diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index 09dd510c4a5..576ce463cf4 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio.txt @@ -78,7 +78,8 @@ Identifying GPIOs ----------------- GPIOs are identified by unsigned integers in the range 0..MAX_INT. That reserves "negative" numbers for other purposes like marking signals as -"not available on this board", or indicating faults. +"not available on this board", or indicating faults. Code that doesn't +touch the underlying hardware treats these integers as opaque cookies. Platforms define how they use those integers, and usually #define symbols for the GPIO lines so that board-specific setup code directly corresponds @@ -139,10 +140,10 @@ issues including wire-OR and output latencies. The get/set calls have no error returns because "invalid GPIO" should have been reported earlier in gpio_set_direction(). However, note that not all platforms can read the value of output pins; those that can't should always -return zero. Also, these calls will be ignored for GPIOs that can't safely -be accessed wihtout sleeping (see below). +return zero. Also, using these calls for GPIOs that can't safely be accessed +without sleeping (see below) is an error. -Platform-specific implementations are encouraged to optimise the two +Platform-specific implementations are encouraged to optimize the two calls to access the GPIO value in cases where the GPIO number (and for output, value) are constant. It's normal for them to need only a couple of instructions in such cases (reading or writing a hardware register), @@ -239,7 +240,8 @@ options are part of the IRQ interface, e.g. IRQF_TRIGGER_FALLING, as are system wakeup capabilities. Non-error values returned from irq_to_gpio() would most commonly be used -with gpio_get_value(). +with gpio_get_value(), for example to initialize or update driver state +when the IRQ is edge-triggered. @@ -260,9 +262,10 @@ pullups (or pulldowns) so that the on-chip ones should not be used. There are other system-specific mechanisms that are not specified here, like the aforementioned options for input de-glitching and wire-OR output. Hardware may support reading or writing GPIOs in gangs, but that's usually -configuration dependednt: for GPIOs sharing the same bank. (GPIOs are +configuration dependent: for GPIOs sharing the same bank. (GPIOs are commonly grouped in banks of 16 or 32, with a given SOC having several such -banks.) Code relying on such mechanisms will necessarily be nonportable. +banks.) Some systems can trigger IRQs from output GPIOs. Code relying on +such mechanisms will necessarily be nonportable. Dynamic definition of GPIOs is not currently supported; for example, as a side effect of configuring an add-on board with some GPIO expanders. diff --git a/Documentation/hrtimer/timer_stats.txt b/Documentation/hrtimer/timer_stats.txt new file mode 100644 index 00000000000..27f782e3593 --- /dev/null +++ b/Documentation/hrtimer/timer_stats.txt @@ -0,0 +1,68 @@ +timer_stats - timer usage statistics +------------------------------------ + +timer_stats is a debugging facility to make the timer (ab)usage in a Linux +system visible to kernel and userspace developers. It is not intended for +production usage as it adds significant overhead to the (hr)timer code and the +(hr)timer data structures. + +timer_stats should be used by kernel and userspace developers to verify that +their code does not make unduly use of timers. This helps to avoid unnecessary +wakeups, which should be avoided to optimize power consumption. + +It can be enabled by CONFIG_TIMER_STATS in the "Kernel hacking" configuration +section. + +timer_stats collects information about the timer events which are fired in a +Linux system over a sample period: + +- the pid of the task(process) which initialized the timer +- the name of the process which initialized the timer +- the function where the timer was intialized +- the callback function which is associated to the timer +- the number of events (callbacks) + +timer_stats adds an entry to /proc: /proc/timer_stats + +This entry is used to control the statistics functionality and to read out the +sampled information. + +The timer_stats functionality is inactive on bootup. + +To activate a sample period issue: +# echo 1 >/proc/timer_stats + +To stop a sample period issue: +# echo 0 >/proc/timer_stats + +The statistics can be retrieved by: +# cat /proc/timer_stats + +The readout of /proc/timer_stats automatically disables sampling. The sampled +information is kept until a new sample period is started. This allows multiple +readouts. + +Sample output of /proc/timer_stats: + +Timerstats sample period: 3.888770 s + 12, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick) + 15, 1 swapper hcd_submit_urb (rh_timer_func) + 4, 959 kedac schedule_timeout (process_timeout) + 1, 0 swapper page_writeback_init (wb_timer_fn) + 28, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick) + 22, 2948 IRQ 4 tty_flip_buffer_push (delayed_work_timer_fn) + 3, 3100 bash schedule_timeout (process_timeout) + 1, 1 swapper queue_delayed_work_on (delayed_work_timer_fn) + 1, 1 swapper queue_delayed_work_on (delayed_work_timer_fn) + 1, 1 swapper neigh_table_init_no_netlink (neigh_periodic_timer) + 1, 2292 ip __netdev_watchdog_up (dev_watchdog) + 1, 23 events/1 do_cache_clean (delayed_work_timer_fn) +90 total events, 30.0 events/sec + +The first column is the number of events, the second column the pid, the third +column is the name of the process. The forth column shows the function which +initialized the timer and in parantheses the callback function which was +executed on expiry. + + Thomas, Ingo + diff --git a/Documentation/hrtimers/highres.txt b/Documentation/hrtimers/highres.txt new file mode 100644 index 00000000000..ce0e9a91e15 --- /dev/null +++ b/Documentation/hrtimers/highres.txt @@ -0,0 +1,249 @@ +High resolution timers and dynamic ticks design notes +----------------------------------------------------- + +Further information can be found in the paper of the OLS 2006 talk "hrtimers +and beyond". The paper is part of the OLS 2006 Proceedings Volume 1, which can +be found on the OLS website: +http://www.linuxsymposium.org/2006/linuxsymposium_procv1.pdf + +The slides to this talk are available from: +http://tglx.de/projects/hrtimers/ols2006-hrtimers.pdf + +The slides contain five figures (pages 2, 15, 18, 20, 22), which illustrate the +changes in the time(r) related Linux subsystems. Figure #1 (p. 2) shows the +design of the Linux time(r) system before hrtimers and other building blocks +got merged into mainline. + +Note: the paper and the slides are talking about "clock event source", while we +switched to the name "clock event devices" in meantime. + +The design contains the following basic building blocks: + +- hrtimer base infrastructure +- timeofday and clock source management +- clock event management +- high resolution timer functionality +- dynamic ticks + + +hrtimer base infrastructure +--------------------------- + +The hrtimer base infrastructure was merged into the 2.6.16 kernel. Details of +the base implementation are covered in Documentation/hrtimers/hrtimer.txt. See +also figure #2 (OLS slides p. 15) + +The main differences to the timer wheel, which holds the armed timer_list type +timers are: + - time ordered enqueueing into a rb-tree + - independent of ticks (the processing is based on nanoseconds) + + +timeofday and clock source management +------------------------------------- + +John Stultz's Generic Time Of Day (GTOD) framework moves a large portion of +code out of the architecture-specific areas into a generic management +framework, as illustrated in figure #3 (OLS slides p. 18). The architecture +specific portion is reduced to the low level hardware details of the clock +sources, which are registered in the framework and selected on a quality based +decision. The low level code provides hardware setup and readout routines and +initializes data structures, which are used by the generic time keeping code to +convert the clock ticks to nanosecond based time values. All other time keeping +related functionality is moved into the generic code. The GTOD base patch got +merged into the 2.6.18 kernel. + +Further information about the Generic Time Of Day framework is available in the +OLS 2005 Proceedings Volume 1: +http://www.linuxsymposium.org/2005/linuxsymposium_procv1.pdf + +The paper "We Are Not Getting Any Younger: A New Approach to Time and +Timers" was written by J. Stultz, D.V. Hart, & N. Aravamudan. + +Figure #3 (OLS slides p.18) illustrates the transformation. + + +clock event management +---------------------- + +While clock sources provide read access to the monotonically increasing time +value, clock event devices are used to schedule the next event +interrupt(s). The next event is currently defined to be periodic, with its +period defined at compile time. The setup and selection of the event device +for various event driven functionalities is hardwired into the architecture +dependent code. This results in duplicated code across all architectures and +makes it extremely difficult to change the configuration of the system to use +event interrupt devices other than those already built into the +architecture. Another implication of the current design is that it is necessary +to touch all the architecture-specific implementations in order to provide new +functionality like high resolution timers or dynamic ticks. + +The clock events subsystem tries to address this problem by providing a generic +solution to manage clock event devices and their usage for the various clock +event driven kernel functionalities. The goal of the clock event subsystem is +to minimize the clock event related architecture dependent code to the pure +hardware related handling and to allow easy addition and utilization of new +clock event devices. It also minimizes the duplicated code across the +architectures as it provides generic functionality down to the interrupt +service handler, which is almost inherently hardware dependent. + +Clock event devices are registered either by the architecture dependent boot +code or at module insertion time. Each clock event device fills a data +structure with clock-specific property parameters and callback functions. The +clock event management decides, by using the specified property parameters, the +set of system functions a clock event device will be used to support. This +includes the distinction of per-CPU and per-system global event devices. + +System-level global event devices are used for the Linux periodic tick. Per-CPU +event devices are used to provide local CPU functionality such as process +accounting, profiling, and high resolution timers. + +The management layer assignes one or more of the folliwing functions to a clock +event device: + - system global periodic tick (jiffies update) + - cpu local update_process_times + - cpu local profiling + - cpu local next event interrupt (non periodic mode) + +The clock event device delegates the selection of those timer interrupt related +functions completely to the management layer. The clock management layer stores +a function pointer in the device description structure, which has to be called +from the hardware level handler. This removes a lot of duplicated code from the +architecture specific timer interrupt handlers and hands the control over the +clock event devices and the assignment of timer interrupt related functionality +to the core code. + +The clock event layer API is rather small. Aside from the clock event device +registration interface it provides functions to schedule the next event +interrupt, clock event device notification service and support for suspend and +resume. + +The framework adds about 700 lines of code which results in a 2KB increase of +the kernel binary size. The conversion of i386 removes about 100 lines of +code. The binary size decrease is in the range of 400 byte. We believe that the +increase of flexibility and the avoidance of duplicated code across +architectures justifies the slight increase of the binary size. + +The conversion of an architecture has no functional impact, but allows to +utilize the high resolution and dynamic tick functionalites without any change +to the clock event device and timer interrupt code. After the conversion the +enabling of high resolution timers and dynamic ticks is simply provided by +adding the kernel/time/Kconfig file to the architecture specific Kconfig and +adding the dynamic tick specific calls to the idle routine (a total of 3 lines +added to the idle function and the Kconfig file) + +Figure #4 (OLS slides p.20) illustrates the transformation. + + +high resolution timer functionality +----------------------------------- + +During system boot it is not possible to use the high resolution timer +functionality, while making it possible would be difficult and would serve no +useful function. The initialization of the clock event device framework, the +clock source framework (GTOD) and hrtimers itself has to be done and +appropriate clock sources and clock event devices have to be registered before +the high resolution functionality can work. Up to the point where hrtimers are +initialized, the system works in the usual low resolution periodic mode. The +clock source and the clock event device layers provide notification functions +which inform hrtimers about availability of new hardware. hrtimers validates +the usability of the registered clock sources and clock event devices before +switching to high resolution mode. This ensures also that a kernel which is +configured for high resolution timers can run on a system which lacks the +necessary hardware support. + +The high resolution timer code does not support SMP machines which have only +global clock event devices. The support of such hardware would involve IPI +calls when an interrupt happens. The overhead would be much larger than the +benefit. This is the reason why we currently disable high resolution and +dynamic ticks on i386 SMP systems which stop the local APIC in C3 power +state. A workaround is available as an idea, but the problem has not been +tackled yet. + +The time ordered insertion of timers provides all the infrastructure to decide +whether the event device has to be reprogrammed when a timer is added. The +decision is made per timer base and synchronized across per-cpu timer bases in +a support function. The design allows the system to utilize separate per-CPU +clock event devices for the per-CPU timer bases, but currently only one +reprogrammable clock event device per-CPU is utilized. + +When the timer interrupt happens, the next event interrupt handler is called +from the clock event distribution code and moves expired timers from the +red-black tree to a separate double linked list and invokes the softirq +handler. An additional mode field in the hrtimer structure allows the system to +execute callback functions directly from the next event interrupt handler. This +is restricted to code which can safely be executed in the hard interrupt +context. This applies, for example, to the common case of a wakeup function as +used by nanosleep. The advantage of executing the handler in the interrupt +context is the avoidance of up to two context switches - from the interrupted +context to the softirq and to the task which is woken up by the expired +timer. + +Once a system has switched to high resolution mode, the periodic tick is +switched off. This disables the per system global periodic clock event device - +e.g. the PIT on i386 SMP systems. + +The periodic tick functionality is provided by an per-cpu hrtimer. The callback +function is executed in the next event interrupt context and updates jiffies +and calls update_process_times and profiling. The implementation of the hrtimer +based periodic tick is designed to be extended with dynamic tick functionality. +This allows to use a single clock event device to schedule high resolution +timer and periodic events (jiffies tick, profiling, process accounting) on UP +systems. This has been proved to work with the PIT on i386 and the Incrementer +on PPC. + +The softirq for running the hrtimer queues and executing the callbacks has been +separated from the tick bound timer softirq to allow accurate delivery of high +resolution timer signals which are used by itimer and POSIX interval +timers. The execution of this softirq can still be delayed by other softirqs, +but the overall latencies have been significantly improved by this separation. + +Figure #5 (OLS slides p.22) illustrates the transformation. + + +dynamic ticks +------------- + +Dynamic ticks are the logical consequence of the hrtimer based periodic tick +replacement (sched_tick). The functionality of the sched_tick hrtimer is +extended by three functions: + +- hrtimer_stop_sched_tick +- hrtimer_restart_sched_tick +- hrtimer_update_jiffies + +hrtimer_stop_sched_tick() is called when a CPU goes into idle state. The code +evaluates the next scheduled timer event (from both hrtimers and the timer +wheel) and in case that the next event is further away than the next tick it +reprograms the sched_tick to this future event, to allow longer idle sleeps +without worthless interruption by the periodic tick. The function is also +called when an interrupt happens during the idle period, which does not cause a +reschedule. The call is necessary as the interrupt handler might have armed a +new timer whose expiry time is before the time which was identified as the +nearest event in the previous call to hrtimer_stop_sched_tick. + +hrtimer_restart_sched_tick() is called when the CPU leaves the idle state before +it calls schedule(). hrtimer_restart_sched_tick() resumes the periodic tick, +which is kept active until the next call to hrtimer_stop_sched_tick(). + +hrtimer_update_jiffies() is called from irq_enter() when an interrupt happens +in the idle period to make sure that jiffies are up to date and the interrupt +handler has not to deal with an eventually stale jiffy value. + +The dynamic tick feature provides statistical values which are exported to +userspace via /proc/stats and can be made available for enhanced power +management control. + +The implementation leaves room for further development like full tickless +systems, where the time slice is controlled by the scheduler, variable +frequency profiling, and a complete removal of jiffies in the future. + + +Aside the current initial submission of i386 support, the patchset has been +extended to x86_64 and ARM already. Initial (work in progress) support is also +available for MIPS and PowerPC. + + Thomas, Ingo + + + diff --git a/Documentation/hrtimers.txt b/Documentation/hrtimers/hrtimers.txt index ce31f65e12e..ce31f65e12e 100644 --- a/Documentation/hrtimers.txt +++ b/Documentation/hrtimers/hrtimers.txt diff --git a/Documentation/i2c/busses/i2c-i801 b/Documentation/i2c/busses/i2c-i801 index 3db69a086c4..c34f0db78a3 100644 --- a/Documentation/i2c/busses/i2c-i801 +++ b/Documentation/i2c/busses/i2c-i801 @@ -48,14 +48,9 @@ following: The SMBus controller is function 3 in device 1f. Class 0c05 is SMBus Serial Controller. -If you do NOT see the 24x3 device at function 3, and you can't figure out -any way in the BIOS to enable it, - The ICH chips are quite similar to Intel's PIIX4 chip, at least in the SMBus controller. -See the file i2c-piix4 for some additional information. - Process Call Support -------------------- @@ -74,6 +69,61 @@ SMBus 2.0 Support The 82801DB (ICH4) and later chips support several SMBus 2.0 features. + +Hidden ICH SMBus +---------------- + +If your system has an Intel ICH south bridge, but you do NOT see the +SMBus device at 00:1f.3 in lspci, and you can't figure out any way in the +BIOS to enable it, it means it has been hidden by the BIOS code. Asus is +well known for first doing this on their P4B motherboard, and many other +boards after that. Some vendor machines are affected as well. + +The first thing to try is the "i2c_ec" ACPI driver. It could be that the +SMBus was hidden on purpose because it'll be driven by ACPI. If the +i2c_ec driver works for you, just forget about the i2c-i801 driver and +don't try to unhide the ICH SMBus. Even if i2c_ec doesn't work, you +better make sure that the SMBus isn't used by the ACPI code. Try loading +the "fan" and "thermal" drivers, and check in /proc/acpi/fan and +/proc/acpi/thermal_zone. If you find anything there, it's likely that +the ACPI is accessing the SMBus and it's safer not to unhide it. Only +once you are certain that ACPI isn't using the SMBus, you can attempt +to unhide it. + +In order to unhide the SMBus, we need to change the value of a PCI +register before the kernel enumerates the PCI devices. This is done in +drivers/pci/quirks.c, where all affected boards must be listed (see +function asus_hides_smbus_hostbridge.) If the SMBus device is missing, +and you think there's something interesting on the SMBus (e.g. a +hardware monitoring chip), you need to add your board to the list. + +The motherboard is identified using the subvendor and subdevice IDs of the +host bridge PCI device. Get yours with "lspci -n -v -s 00:00.0": + +00:00.0 Class 0600: 8086:2570 (rev 02) + Subsystem: 1043:80f2 + Flags: bus master, fast devsel, latency 0 + Memory at fc000000 (32-bit, prefetchable) [size=32M] + Capabilities: [e4] #09 [2106] + Capabilities: [a0] AGP version 3.0 + +Here the host bridge ID is 2570 (82865G/PE/P), the subvendor ID is 1043 +(Asus) and the subdevice ID is 80f2 (P4P800-X). You can find the symbolic +names for the bridge ID and the subvendor ID in include/linux/pci_ids.h, +and then add a case for your subdevice ID at the right place in +drivers/pci/quirks.c. Then please give it very good testing, to make sure +that the unhidden SMBus doesn't conflict with e.g. ACPI. + +If it works, proves useful (i.e. there are usable chips on the SMBus) +and seems safe, please submit a patch for inclusion into the kernel. + +Note: There's a useful script in lm_sensors 2.10.2 and later, named +unhide_ICH_SMBus (in prog/hotplug), which uses the fakephp driver to +temporarily unhide the SMBus without having to patch and recompile your +kernel. It's very convenient if you just want to check if there's +anything interesting on your hidden ICH SMBus. + + ********************** The lm_sensors project gratefully acknowledges the support of Texas Instruments in the initial development of this driver. diff --git a/Documentation/i2c/busses/i2c-parport b/Documentation/i2c/busses/i2c-parport index 77b995dfca2..dceaba1ad93 100644 --- a/Documentation/i2c/busses/i2c-parport +++ b/Documentation/i2c/busses/i2c-parport @@ -19,6 +19,7 @@ It currently supports the following devices: * (type=4) Analog Devices ADM1032 evaluation board * (type=5) Analog Devices evaluation boards: ADM1025, ADM1030, ADM1031 * (type=6) Barco LPT->DVI (K5800236) adapter + * (type=7) One For All JP1 parallel port adapter These devices use different pinout configurations, so you have to tell the driver what you have, using the type module parameter. There is no @@ -157,3 +158,17 @@ many more, using /dev/velleman. http://home.wanadoo.nl/hihihi/libk8005.htm http://struyve.mine.nu:8080/index.php?block=k8000 http://sourceforge.net/projects/libk8005/ + + +One For All JP1 parallel port adapter +------------------------------------- + +The JP1 project revolves around a set of remote controls which expose +the I2C bus their internal configuration EEPROM lives on via a 6 pin +jumper in the battery compartment. More details can be found at: + +http://www.hifi-remote.com/jp1/ + +Details of the simple parallel port hardware can be found at: + +http://www.hifi-remote.com/jp1/hardware.shtml diff --git a/Documentation/i2c/busses/i2c-piix4 b/Documentation/i2c/busses/i2c-piix4 index 92147633323..7cbe43fa270 100644 --- a/Documentation/i2c/busses/i2c-piix4 +++ b/Documentation/i2c/busses/i2c-piix4 @@ -6,7 +6,7 @@ Supported adapters: Datasheet: Publicly available at the Intel website * ServerWorks OSB4, CSB5, CSB6 and HT-1000 southbridges Datasheet: Only available via NDA from ServerWorks - * ATI IXP southbridges IXP200, IXP300, IXP400 + * ATI IXP200, IXP300, IXP400 and SB600 southbridges Datasheet: Not publicly available * Standard Microsystems (SMSC) SLC90E66 (Victory66) southbridge Datasheet: Publicly available at the SMSC website http://www.smsc.com diff --git a/Documentation/i2c/busses/i2c-viapro b/Documentation/i2c/busses/i2c-viapro index 25680346e0a..775f489e86f 100644 --- a/Documentation/i2c/busses/i2c-viapro +++ b/Documentation/i2c/busses/i2c-viapro @@ -13,6 +13,9 @@ Supported adapters: * VIA Technologies, Inc. VT8235, VT8237R, VT8237A, VT8251 Datasheet: available on request and under NDA from VIA + * VIA Technologies, Inc. CX700 + Datasheet: available on request and under NDA from VIA + Authors: Kyösti Mälkki <kmalkki@cc.hut.fi>, Mark D. Studebaker <mdsxyz123@yahoo.com>, @@ -44,6 +47,7 @@ Your lspci -n listing must show one of these : device 1106:3227 (VT8237R) device 1106:3337 (VT8237A) device 1106:3287 (VT8251) + device 1106:8324 (CX700) If none of these show up, you should look in the BIOS for settings like enable ACPI / SMBus or even USB. @@ -51,3 +55,6 @@ enable ACPI / SMBus or even USB. Except for the oldest chips (VT82C596A/B, VT82C686A and most probably VT8231), this driver supports I2C block transactions. Such transactions are mainly useful to read from and write to EEPROMs. + +The CX700 additionally appears to support SMBus PEC, although this driver +doesn't implement it yet. diff --git a/Documentation/i2c/porting-clients b/Documentation/i2c/porting-clients index f03c2a02f80..ca272b263a9 100644 --- a/Documentation/i2c/porting-clients +++ b/Documentation/i2c/porting-clients @@ -129,6 +129,12 @@ Technical changes: structure, those name member should be initialized to a driver name string. i2c_driver itself has no name member anymore. +* [Driver model] Instead of shutdown or reboot notifiers, provide a + shutdown() method in your driver. + +* [Power management] Use the driver model suspend() and resume() + callbacks instead of the obsolete pm_register() calls. + Coding policy: * [Copyright] Use (C), not (c), for copyright. diff --git a/Documentation/i2c/smbus-protocol b/Documentation/i2c/smbus-protocol index 09f5e5ca492..8a653c60d25 100644 --- a/Documentation/i2c/smbus-protocol +++ b/Documentation/i2c/smbus-protocol @@ -97,7 +97,7 @@ SMBus Write Word Data ===================== This is the opposite operation of the Read Word Data command. 16 bits -of data is read from a device, from a designated register that is +of data is written to a device, to the designated register that is specified through the Comm byte. S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] P diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index 3a057c8e550..fbcff96f4ca 100644 --- a/Documentation/i2c/writing-clients +++ b/Documentation/i2c/writing-clients @@ -21,20 +21,26 @@ The driver structure Usually, you will implement a single driver structure, and instantiate all clients from it. Remember, a driver structure contains general access -routines, a client structure specific information like the actual I2C -address. +routines, and should be zero-initialized except for fields with data you +provide. A client structure holds device-specific information like the +driver model device node, and its I2C address. static struct i2c_driver foo_driver = { .driver = { .name = "foo", }, - .attach_adapter = &foo_attach_adapter, - .detach_client = &foo_detach_client, - .command = &foo_command /* may be NULL */ + .attach_adapter = foo_attach_adapter, + .detach_client = foo_detach_client, + .shutdown = foo_shutdown, /* optional */ + .suspend = foo_suspend, /* optional */ + .resume = foo_resume, /* optional */ + .command = foo_command, /* optional */ } -The name field must match the driver name, including the case. It must not -contain spaces, and may be up to 31 characters long. +The name field is the driver name, and must not contain spaces. It +should match the module name (if the driver can be compiled as a module), +although you can use MODULE_ALIAS (passing "foo" in this example) to add +another name for the module. All other fields are for call-back functions which will be explained below. @@ -43,11 +49,18 @@ below. Extra client data ================= -The client structure has a special `data' field that can point to any -structure at all. You can use this to keep client-specific data. You +Each client structure has a special `data' field that can point to any +structure at all. You should use this to keep device-specific data, +especially in drivers that handle multiple I2C or SMBUS devices. You do not always need this, but especially for `sensors' drivers, it can be very useful. + /* store the value */ + void i2c_set_clientdata(struct i2c_client *client, void *data); + + /* retrieve the value */ + void *i2c_get_clientdata(struct i2c_client *client); + An example structure is below. struct foo_data { @@ -493,6 +506,33 @@ by `__init_data'. Hose functions and structures can be removed after kernel booting (or module loading) is completed. +Power Management +================ + +If your I2C device needs special handling when entering a system low +power state -- like putting a transceiver into a low power mode, or +activating a system wakeup mechanism -- do that in the suspend() method. +The resume() method should reverse what the suspend() method does. + +These are standard driver model calls, and they work just like they +would for any other driver stack. The calls can sleep, and can use +I2C messaging to the device being suspended or resumed (since their +parent I2C adapter is active when these calls are issued, and IRQs +are still enabled). + + +System Shutdown +=============== + +If your I2C device needs special handling when the system shuts down +or reboots (including kexec) -- like turning something off -- use a +shutdown() method. + +Again, this is a standard driver model call, working just like it +would for any other driver stack: the calls can sleep, and can use +I2C messaging. + + Command function ================ diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index d25acd51e18..abd575cfc75 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -104,6 +104,9 @@ loader, and have no meaning to the kernel directly. Do not modify the syntax of boot loader parameters without extreme need or coordination with <Documentation/i386/boot.txt>. +There are also arch-specific kernel-parameters not documented here. +See for example <Documentation/x86_64/boot-options.txt>. + Note that ALL kernel parameters listed below are CASE SENSITIVE, and that a trailing = on the name of any parameter states that that parameter will be entered as an environment variable, whereas its absence indicates that @@ -361,6 +364,11 @@ and is between 256 and 4096 characters. It is defined in the file clocksource is not available, it defaults to PIT. Format: { pit | tsc | cyclone | pmtmr } + code_bytes [IA32] How many bytes of object code to print in an + oops report. + Range: 0 - 8192 + Default: 64 + disable_8254_timer enable_8254_timer [IA32/X86_64] Disable/Enable interrupt 0 timer routing @@ -601,6 +609,10 @@ and is between 256 and 4096 characters. It is defined in the file highmem otherwise. This also works to reduce highmem size on bigger boxes. + highres= [KNL] Enable/disable high resolution timer mode. + Valid parameters: "on", "off" + Default: "on" + hisax= [HW,ISDN] See Documentation/isdn/README.HiSax. @@ -1070,6 +1082,10 @@ and is between 256 and 4096 characters. It is defined in the file in certain environments such as networked servers or real-time systems. + nohz= [KNL] Boottime enable/disable dynamic ticks + Valid arguments: on, off + Default: on + noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing noirqdebug [IA-32] Disables the code which attempts to detect and diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt index 33994271cb3..3b514672b80 100644 --- a/Documentation/powerpc/booting-without-of.txt +++ b/Documentation/powerpc/booting-without-of.txt @@ -1334,6 +1334,9 @@ platforms are moved over to use the flattened-device-tree model. fsl-usb2-mph compatible controllers. Either this property or "port0" (or both) must be defined for "fsl-usb2-mph" compatible controllers. + - dr_mode : indicates the working mode for "fsl-usb2-dr" compatible + controllers. Can be "host", "peripheral", or "otg". Default to + "host" if not defined for backward compatibility. Recommended properties : - interrupts : <a b> where a is the interrupt number and b is a @@ -1367,6 +1370,7 @@ platforms are moved over to use the flattened-device-tree model. #size-cells = <0>; interrupt-parent = <700>; interrupts = <26 1>; + dr_mode = "otg"; phy = "ulpi"; }; diff --git a/Documentation/powerpc/mpc52xx-device-tree-bindings.txt b/Documentation/powerpc/mpc52xx-device-tree-bindings.txt index 69f016f02bb..e59fcbbe338 100644 --- a/Documentation/powerpc/mpc52xx-device-tree-bindings.txt +++ b/Documentation/powerpc/mpc52xx-device-tree-bindings.txt @@ -1,7 +1,7 @@ -MPC52xx Device Tree Bindings +MPC5200 Device Tree Bindings ---------------------------- -(c) 2006 Secret Lab Technologies Ltd +(c) 2006-2007 Secret Lab Technologies Ltd Grant Likely <grant.likely at secretlab.ca> ********** DRAFT *********** @@ -20,11 +20,11 @@ described in Documentation/powerpc/booting-without-of.txt), or passed by Open Firmare (IEEE 1275) compatible firmware using an OF compatible client interface API. -This document specifies the requirements on the device-tree for mpc52xx +This document specifies the requirements on the device-tree for mpc5200 based boards. These requirements are above and beyond the details specified in either the OpenFirmware spec or booting-without-of.txt -All new mpc52xx-based boards are expected to match this document. In +All new mpc5200-based boards are expected to match this document. In cases where this document is not sufficient to support a new board port, this document should be updated as part of adding the new board support. @@ -32,26 +32,26 @@ II - Philosophy =============== The core of this document is naming convention. The whole point of defining this convention is to reduce or eliminate the number of -special cases required to support a 52xx board. If all 52xx boards -follow the same convention, then generic 52xx support code will work +special cases required to support a 5200 board. If all 5200 boards +follow the same convention, then generic 5200 support code will work rather than coding special cases for each new board. This section tries to capture the thought process behind why the naming convention is what it is. -1. Node names -------------- +1. names +--------- There is strong convention/requirements already established for children of the root node. 'cpus' describes the processor cores, 'memory' describes memory, and 'chosen' provides boot configuration. Other nodes are added to describe devices attached to the processor local bus. + Following convention already established with other system-on-chip -processors, MPC52xx boards must have an 'soc5200' node as a child of the -root node. +processors, 5200 device trees should use the name 'soc5200' for the +parent node of on chip devices, and the root node should be its parent. -The soc5200 node holds child nodes for all on chip devices. Child nodes -are typically named after the configured function. ie. the FEC node is -named 'ethernet', and a PSC in uart mode is named 'serial'. +Child nodes are typically named after the configured function. ie. +the FEC node is named 'ethernet', and a PSC in uart mode is named 'serial'. 2. device_type property ----------------------- @@ -66,28 +66,47 @@ exactly. Since device_type isn't enough to match devices to drivers, there also needs to be a naming convention for the compatible property. Compatible is an list of device descriptions sorted from specific to generic. For -the mpc52xx, the required format for each compatible value is -<chip>-<device>[-<mode>]. At the minimum, the list shall contain two -items; the first specifying the exact chip, and the second specifying -mpc52xx for the chip. - -ie. ethernet on mpc5200b: compatible = "mpc5200b-ethernet\0mpc52xx-ethernet" - -The idea here is that most drivers will match to the most generic field -in the compatible list (mpc52xx-*), but can also test the more specific -field for enabling bug fixes or extra features. +the mpc5200, the required format for each compatible value is +<chip>-<device>[-<mode>]. The OS should be able to match a device driver +to the device based solely on the compatible value. If two drivers +match on the compatible list; the 'most compatible' driver should be +selected. + +The split between the MPC5200 and the MPC5200B leaves a bit of a +connundrum. How should the compatible property be set up to provide +maximum compatability information; but still acurately describe the +chip? For the MPC5200; the answer is easy. Most of the SoC devices +originally appeared on the MPC5200. Since they didn't exist anywhere +else; the 5200 compatible properties will contain only one item; +"mpc5200-<device>". + +The 5200B is almost the same as the 5200, but not quite. It fixes +silicon bugs and it adds a small number of enhancements. Most of the +devices either provide exactly the same interface as on the 5200. A few +devices have extra functions but still have a backwards compatible mode. +To express this infomation as completely as possible, 5200B device trees +should have two items in the compatible list; +"mpc5200b-<device>\0mpc5200-<device>". It is *strongly* recommended +that 5200B device trees follow this convention (instead of only listing +the base mpc5200 item). + +If another chip appear on the market with one of the mpc5200 SoC +devices, then the compatible list should include mpc5200-<device>. + +ie. ethernet on mpc5200: compatible = "mpc5200-ethernet" + ethernet on mpc5200b: compatible = "mpc5200b-ethernet\0mpc5200-ethernet" Modal devices, like PSCs, also append the configured function to the end of the compatible field. ie. A PSC in i2s mode would specify -"mpc52xx-psc-i2s", not "mpc52xx-i2s". This convention is chosen to +"mpc5200-psc-i2s", not "mpc5200-i2s". This convention is chosen to avoid naming conflicts with non-psc devices providing the same -function. For example, "mpc52xx-spi" and "mpc52xx-psc-spi" describe +function. For example, "mpc5200-spi" and "mpc5200-psc-spi" describe the mpc5200 simple spi device and a PSC spi mode respectively. If the soc device is more generic and present on other SOCs, the compatible property can specify the more generic device type also. -ie. mscan: compatible = "mpc5200-mscan\0mpc52xx-mscan\0fsl,mscan"; +ie. mscan: compatible = "mpc5200-mscan\0fsl,mscan"; At the time of writing, exact chip may be either 'mpc5200' or 'mpc5200b'. @@ -96,7 +115,7 @@ Device drivers should always try to match as generically as possible. III - Structure =============== -The device tree for an mpc52xx board follows the structure defined in +The device tree for an mpc5200 board follows the structure defined in booting-without-of.txt with the following additional notes: 0) the root node @@ -115,7 +134,7 @@ Typical memory description node; see booting-without-of. 3) The soc5200 node ------------------- -This node describes the on chip SOC peripherals. Every mpc52xx based +This node describes the on chip SOC peripherals. Every mpc5200 based board will have this node, and as such there is a common naming convention for SOC devices. @@ -125,71 +144,111 @@ name type description device_type string must be "soc" ranges int should be <0 baseaddr baseaddr+10000> reg int must be <baseaddr 10000> +compatible string mpc5200: "mpc5200-soc" + mpc5200b: "mpc5200b-soc\0mpc5200-soc" +system-frequency int Fsystem frequency; source of all + other clocks. +bus-frequency int IPB bus frequency in HZ. Clock rate + used by most of the soc devices. +#interrupt-cells int must be <3>. Recommended properties: name type description ---- ---- ----------- -compatible string should be "<chip>-soc\0mpc52xx-soc" - ie. "mpc5200b-soc\0mpc52xx-soc" -#interrupt-cells int must be <3>. If it is not defined - here then it must be defined in every - soc device node. -bus-frequency int IPB bus frequency in HZ. Clock rate - used by most of the soc devices. - Defining it here avoids needing it - added to every device node. +model string Exact model of the chip; + ie: model="fsl,mpc5200" +revision string Silicon revision of chip + ie: revision="M08A" + +The 'model' and 'revision' properties are *strongly* recommended. Having +them presence acts as a bit of a safety net for working around as yet +undiscovered bugs on one version of silicon. For example, device drivers +can use the model and revision properties to decide if a bug fix should +be turned on. 4) soc5200 child nodes ---------------------- Any on chip SOC devices available to Linux must appear as soc5200 child nodes. -Note: in the tables below, '*' matches all <chip> values. ie. -*-pic would translate to "mpc5200-pic\0mpc52xx-pic" +Note: The tables below show the value for the mpc5200. A mpc5200b device +tree should use the "mpc5200b-<device>\0mpc5200-<device> form. Required soc5200 child nodes: name device_type compatible Description ---- ----------- ---------- ----------- -cdm@<addr> cdm *-cmd Clock Distribution -pic@<addr> interrupt-controller *-pic need an interrupt +cdm@<addr> cdm mpc5200-cmd Clock Distribution +pic@<addr> interrupt-controller mpc5200-pic need an interrupt controller to boot -bestcomm@<addr> dma-controller *-bestcomm 52xx pic also requires - the bestcomm device +bestcomm@<addr> dma-controller mpc5200-bestcomm 5200 pic also requires + the bestcomm device Recommended soc5200 child nodes; populate as needed for your board -name device_type compatible Description ----- ----------- ---------- ----------- -gpt@<addr> gpt *-gpt General purpose timers -rtc@<addr> rtc *-rtc Real time clock -mscan@<addr> mscan *-mscan CAN bus controller -pci@<addr> pci *-pci PCI bridge -serial@<addr> serial *-psc-uart PSC in serial mode -i2s@<addr> sound *-psc-i2s PSC in i2s mode -ac97@<addr> sound *-psc-ac97 PSC in ac97 mode -spi@<addr> spi *-psc-spi PSC in spi mode -irda@<addr> irda *-psc-irda PSC in IrDA mode -spi@<addr> spi *-spi MPC52xx spi device -ethernet@<addr> network *-fec MPC52xx ethernet device -ata@<addr> ata *-ata IDE ATA interface -i2c@<addr> i2c *-i2c I2C controller -usb@<addr> usb-ohci-be *-ohci,ohci-be USB controller -xlb@<addr> xlb *-xlb XLB arbritrator +name device_type compatible Description +---- ----------- ---------- ----------- +gpt@<addr> gpt mpc5200-gpt General purpose timers +rtc@<addr> rtc mpc5200-rtc Real time clock +mscan@<addr> mscan mpc5200-mscan CAN bus controller +pci@<addr> pci mpc5200-pci PCI bridge +serial@<addr> serial mpc5200-psc-uart PSC in serial mode +i2s@<addr> sound mpc5200-psc-i2s PSC in i2s mode +ac97@<addr> sound mpc5200-psc-ac97 PSC in ac97 mode +spi@<addr> spi mpc5200-psc-spi PSC in spi mode +irda@<addr> irda mpc5200-psc-irda PSC in IrDA mode +spi@<addr> spi mpc5200-spi MPC5200 spi device +ethernet@<addr> network mpc5200-fec MPC5200 ethernet device +ata@<addr> ata mpc5200-ata IDE ATA interface +i2c@<addr> i2c mpc5200-i2c I2C controller +usb@<addr> usb-ohci-be mpc5200-ohci,ohci-be USB controller +xlb@<addr> xlb mpc5200-xlb XLB arbritrator + +Important child node properties +name type description +---- ---- ----------- +cell-index int When multiple devices are present, is the + index of the device in the hardware (ie. There + are 6 PSC on the 5200 numbered PSC1 to PSC6) + PSC1 has 'cell-index = <0>' + PSC4 has 'cell-index = <3>' + +5) General Purpose Timer nodes (child of soc5200 node) +On the mpc5200 and 5200b, GPT0 has a watchdog timer function. If the board +design supports the internal wdt, then the device node for GPT0 should +include the empty property 'has-wdt'. + +6) PSC nodes (child of soc5200 node) +PSC nodes can define the optional 'port-number' property to force assignment +order of serial ports. For example, PSC5 might be physically connected to +the port labeled 'COM1' and PSC1 wired to 'COM1'. In this case, PSC5 would +have a "port-number = <0>" property, and PSC1 would have "port-number = <1>". + +PSC in i2s mode: The mpc5200 and mpc5200b PSCs are not compatible when in +i2s mode. An 'mpc5200b-psc-i2s' node cannot include 'mpc5200-psc-i2s' in the +compatible field. IV - Extra Notes ================ 1. Interrupt mapping -------------------- -The mpc52xx pic driver splits hardware IRQ numbers into two levels. The +The mpc5200 pic driver splits hardware IRQ numbers into two levels. The split reflects the layout of the PIC hardware itself, which groups interrupts into one of three groups; CRIT, MAIN or PERP. Also, the Bestcomm dma engine has it's own set of interrupt sources which are cascaded off of peripheral interrupt 0, which the driver interprets as a fourth group, SDMA. -The interrupts property for device nodes using the mpc52xx pic consists +The interrupts property for device nodes using the mpc5200 pic consists of three cells; <L1 L2 level> L1 := [CRIT=0, MAIN=1, PERP=2, SDMA=3] L2 := interrupt number; directly mapped from the value in the "ICTL PerStat, MainStat, CritStat Encoded Register" level := [LEVEL_HIGH=0, EDGE_RISING=1, EDGE_FALLING=2, LEVEL_LOW=3] + +2. Shared registers +------------------- +Some SoC devices share registers between them. ie. the i2c devices use +a single clock control register, and almost all device are affected by +the port_config register. Devices which need to manipulate shared regs +should look to the parent SoC node. The soc node is responsible +for arbitrating all shared register access. diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt index 5c86ed6f044..625a21db0c2 100644 --- a/Documentation/x86_64/boot-options.txt +++ b/Documentation/x86_64/boot-options.txt @@ -180,40 +180,81 @@ PCI pci=lastbus=NUMBER Scan upto NUMBER busses, no matter what the mptable says. pci=noacpi Don't use ACPI to set up PCI interrupt routing. -IOMMU - - iommu=[size][,noagp][,off][,force][,noforce][,leak][,memaper[=order]][,merge] - [,forcesac][,fullflush][,nomerge][,noaperture][,calgary] - size set size of iommu (in bytes) - noagp don't initialize the AGP driver and use full aperture. - off don't use the IOMMU - leak turn on simple iommu leak tracing (only when CONFIG_IOMMU_LEAK is on) - memaper[=order] allocate an own aperture over RAM with size 32MB^order. - noforce don't force IOMMU usage. Default. - force Force IOMMU. - merge Do SG merging. Implies force (experimental) - nomerge Don't do SG merging. - forcesac For SAC mode for masks <40bits (experimental) - fullflush Flush IOMMU on each allocation (default) - nofullflush Don't use IOMMU fullflush - allowed overwrite iommu off workarounds for specific chipsets. - soft Use software bounce buffering (default for Intel machines) - noaperture Don't touch the aperture for AGP. - allowdac Allow DMA >4GB - When off all DMA over >4GB is forced through an IOMMU or bounce - buffering. - nodac Forbid DMA >4GB - panic Always panic when IOMMU overflows - calgary Use the Calgary IOMMU if it is available - - swiotlb=pages[,force] - - pages Prereserve that many 128K pages for the software IO bounce buffering. - force Force all IO through the software TLB. - - calgary=[64k,128k,256k,512k,1M,2M,4M,8M] - calgary=[translate_empty_slots] - calgary=[disable=<PCI bus number>] +IOMMU (input/output memory management unit) + + Currently four x86-64 PCI-DMA mapping implementations exist: + + 1. <arch/x86_64/kernel/pci-nommu.c>: use no hardware/software IOMMU at all + (e.g. because you have < 3 GB memory). + Kernel boot message: "PCI-DMA: Disabling IOMMU" + + 2. <arch/x86_64/kernel/pci-gart.c>: AMD GART based hardware IOMMU. + Kernel boot message: "PCI-DMA: using GART IOMMU" + + 3. <arch/x86_64/kernel/pci-swiotlb.c> : Software IOMMU implementation. Used + e.g. if there is no hardware IOMMU in the system and it is need because + you have >3GB memory or told the kernel to us it (iommu=soft)) + Kernel boot message: "PCI-DMA: Using software bounce buffering + for IO (SWIOTLB)" + + 4. <arch/x86_64/pci-calgary.c> : IBM Calgary hardware IOMMU. Used in IBM + pSeries and xSeries servers. This hardware IOMMU supports DMA address + mapping with memory protection, etc. + Kernel boot message: "PCI-DMA: Using Calgary IOMMU" + + iommu=[<size>][,noagp][,off][,force][,noforce][,leak[=<nr_of_leak_pages>] + [,memaper[=<order>]][,merge][,forcesac][,fullflush][,nomerge] + [,noaperture][,calgary] + + General iommu options: + off Don't initialize and use any kind of IOMMU. + noforce Don't force hardware IOMMU usage when it is not needed. + (default). + force Force the use of the hardware IOMMU even when it is + not actually needed (e.g. because < 3 GB memory). + soft Use software bounce buffering (SWIOTLB) (default for + Intel machines). This can be used to prevent the usage + of an available hardware IOMMU. + + iommu options only relevant to the AMD GART hardware IOMMU: + <size> Set the size of the remapping area in bytes. + allowed Overwrite iommu off workarounds for specific chipsets. + fullflush Flush IOMMU on each allocation (default). + nofullflush Don't use IOMMU fullflush. + leak Turn on simple iommu leak tracing (only when + CONFIG_IOMMU_LEAK is on). Default number of leak pages + is 20. + memaper[=<order>] Allocate an own aperture over RAM with size 32MB<<order. + (default: order=1, i.e. 64MB) + merge Do scatter-gather (SG) merging. Implies "force" + (experimental). + nomerge Don't do scatter-gather (SG) merging. + noaperture Ask the IOMMU not to touch the aperture for AGP. + forcesac Force single-address cycle (SAC) mode for masks <40bits + (experimental). + noagp Don't initialize the AGP driver and use full aperture. + allowdac Allow double-address cycle (DAC) mode, i.e. DMA >4GB. + DAC is used with 32-bit PCI to push a 64-bit address in + two cycles. When off all DMA over >4GB is forced through + an IOMMU or software bounce buffering. + nodac Forbid DAC mode, i.e. DMA >4GB. + panic Always panic when IOMMU overflows. + calgary Use the Calgary IOMMU if it is available + + iommu options only relevant to the software bounce buffering (SWIOTLB) IOMMU + implementation: + swiotlb=<pages>[,force] + <pages> Prereserve that many 128K pages for the software IO + bounce buffering. + force Force all IO through the software TLB. + + Settings for the IBM Calgary hardware IOMMU currently found in IBM + pSeries and xSeries machines: + + calgary=[64k,128k,256k,512k,1M,2M,4M,8M] + calgary=[translate_empty_slots] + calgary=[disable=<PCI bus number>] + panic Always panic when IOMMU overflows 64k,...,8M - Set the size of each PCI slot's translation table when using the Calgary IOMMU. This is the size of the translation @@ -234,14 +275,14 @@ IOMMU Debugging - oops=panic Always panic on oopses. Default is to just kill the process, - but there is a small probability of deadlocking the machine. - This will also cause panics on machine check exceptions. - Useful together with panic=30 to trigger a reboot. + oops=panic Always panic on oopses. Default is to just kill the process, + but there is a small probability of deadlocking the machine. + This will also cause panics on machine check exceptions. + Useful together with panic=30 to trigger a reboot. - kstack=N Print that many words from the kernel stack in oops dumps. + kstack=N Print N words from the kernel stack in oops dumps. - pagefaulttrace Dump all page faults. Only useful for extreme debugging + pagefaulttrace Dump all page faults. Only useful for extreme debugging and will create a lot of output. call_trace=[old|both|newfallback|new] @@ -251,15 +292,8 @@ Debugging newfallback: use new unwinder but fall back to old if it gets stuck (default) - call_trace=[old|both|newfallback|new] - old: use old inexact backtracer - new: use new exact dwarf2 unwinder - both: print entries from both - newfallback: use new unwinder but fall back to old if it gets - stuck (default) - -Misc +Miscellaneous noreplacement Don't replace instructions with more appropriate ones for the CPU. This may be useful on asymmetric MP systems - where some CPU have less capabilities than the others. + where some CPUs have less capabilities than others. diff --git a/Documentation/x86_64/cpu-hotplug-spec b/Documentation/x86_64/cpu-hotplug-spec index 5c0fa345e55..3c23e0587db 100644 --- a/Documentation/x86_64/cpu-hotplug-spec +++ b/Documentation/x86_64/cpu-hotplug-spec @@ -2,7 +2,7 @@ Firmware support for CPU hotplug under Linux/x86-64 --------------------------------------------------- Linux/x86-64 supports CPU hotplug now. For various reasons Linux wants to -know in advance boot time the maximum number of CPUs that could be plugged +know in advance of boot time the maximum number of CPUs that could be plugged into the system. ACPI 3.0 currently has no official way to supply this information from the firmware to the operating system. diff --git a/Documentation/x86_64/kernel-stacks b/Documentation/x86_64/kernel-stacks index bddfddd466a..5ad65d51fb9 100644 --- a/Documentation/x86_64/kernel-stacks +++ b/Documentation/x86_64/kernel-stacks @@ -9,9 +9,9 @@ zombie. While the thread is in user space the kernel stack is empty except for the thread_info structure at the bottom. In addition to the per thread stacks, there are specialized stacks -associated with each cpu. These stacks are only used while the kernel -is in control on that cpu, when a cpu returns to user space the -specialized stacks contain no useful data. The main cpu stacks is +associated with each CPU. These stacks are only used while the kernel +is in control on that CPU; when a CPU returns to user space the +specialized stacks contain no useful data. The main CPU stacks are: * Interrupt stack. IRQSTACKSIZE @@ -32,17 +32,17 @@ x86_64 also has a feature which is not available on i386, the ability to automatically switch to a new stack for designated events such as double fault or NMI, which makes it easier to handle these unusual events on x86_64. This feature is called the Interrupt Stack Table -(IST). There can be up to 7 IST entries per cpu. The IST code is an -index into the Task State Segment (TSS), the IST entries in the TSS -point to dedicated stacks, each stack can be a different size. +(IST). There can be up to 7 IST entries per CPU. The IST code is an +index into the Task State Segment (TSS). The IST entries in the TSS +point to dedicated stacks; each stack can be a different size. -An IST is selected by an non-zero value in the IST field of an +An IST is selected by a non-zero value in the IST field of an interrupt-gate descriptor. When an interrupt occurs and the hardware loads such a descriptor, the hardware automatically sets the new stack pointer based on the IST value, then invokes the interrupt handler. If software wants to allow nested IST interrupts then the handler must adjust the IST values on entry to and exit from the interrupt handler. -(this is occasionally done, e.g. for debug exceptions) +(This is occasionally done, e.g. for debug exceptions.) Events with different IST codes (i.e. with different stacks) can be nested. For example, a debug interrupt can safely be interrupted by an @@ -58,17 +58,17 @@ The currently assigned IST stacks are :- Used for interrupt 12 - Stack Fault Exception (#SS). - This allows to recover from invalid stack segments. Rarely + This allows the CPU to recover from invalid stack segments. Rarely happens. * DOUBLEFAULT_STACK. EXCEPTION_STKSZ (PAGE_SIZE). Used for interrupt 8 - Double Fault Exception (#DF). - Invoked when handling a exception causes another exception. Happens - when the kernel is very confused (e.g. kernel stack pointer corrupt) - Using a separate stack allows to recover from it well enough in many - cases to still output an oops. + Invoked when handling one exception causes another exception. Happens + when the kernel is very confused (e.g. kernel stack pointer corrupt). + Using a separate stack allows the kernel to recover from it well enough + in many cases to still output an oops. * NMI_STACK. EXCEPTION_STKSZ (PAGE_SIZE). diff --git a/Documentation/x86_64/machinecheck b/Documentation/x86_64/machinecheck new file mode 100644 index 00000000000..068a6d9904b --- /dev/null +++ b/Documentation/x86_64/machinecheck @@ -0,0 +1,70 @@ + +Configurable sysfs parameters for the x86-64 machine check code. + +Machine checks report internal hardware error conditions detected +by the CPU. Uncorrected errors typically cause a machine check +(often with panic), corrected ones cause a machine check log entry. + +Machine checks are organized in banks (normally associated with +a hardware subsystem) and subevents in a bank. The exact meaning +of the banks and subevent is CPU specific. + +mcelog knows how to decode them. + +When you see the "Machine check errors logged" message in the system +log then mcelog should run to collect and decode machine check entries +from /dev/mcelog. Normally mcelog should be run regularly from a cronjob. + +Each CPU has a directory in /sys/devices/system/machinecheck/machinecheckN +(N = CPU number) + +The directory contains some configurable entries: + +Entries: + +bankNctl +(N bank number) + 64bit Hex bitmask enabling/disabling specific subevents for bank N + When a bit in the bitmask is zero then the respective + subevent will not be reported. + By default all events are enabled. + Note that BIOS maintain another mask to disable specific events + per bank. This is not visible here + +The following entries appear for each CPU, but they are truly shared +between all CPUs. + +check_interval + How often to poll for corrected machine check errors, in seconds + (Note output is hexademical). Default 5 minutes. + +tolerant + Tolerance level. When a machine check exception occurs for a non + corrected machine check the kernel can take different actions. + Since machine check exceptions can happen any time it is sometimes + risky for the kernel to kill a process because it defies + normal kernel locking rules. The tolerance level configures + how hard the kernel tries to recover even at some risk of deadlock. + + 0: always panic, + 1: panic if deadlock possible, + 2: try to avoid panic, + 3: never panic or exit (for testing only) + + Default: 1 + + Note this only makes a difference if the CPU allows recovery + from a machine check exception. Current x86 CPUs generally do not. + +trigger + Program to run when a machine check event is detected. + This is an alternative to running mcelog regularly from cron + and allows to detect events faster. + +TBD document entries for AMD threshold interrupt configuration + +For more details about the x86 machine check architecture +see the Intel and AMD architecture manuals from their developer websites. + +For more details about the architecture see +see http://one.firstfloor.org/~andi/mce.pdf diff --git a/Documentation/x86_64/mm.txt b/Documentation/x86_64/mm.txt index 133561b9cb0..f42798ed1c5 100644 --- a/Documentation/x86_64/mm.txt +++ b/Documentation/x86_64/mm.txt @@ -3,26 +3,26 @@ Virtual memory map with 4 level page tables: -0000000000000000 - 00007fffffffffff (=47bits) user space, different per mm +0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm hole caused by [48:63] sign extension -ffff800000000000 - ffff80ffffffffff (=40bits) guard hole -ffff810000000000 - ffffc0ffffffffff (=46bits) direct mapping of all phys. memory -ffffc10000000000 - ffffc1ffffffffff (=40bits) hole -ffffc20000000000 - ffffe1ffffffffff (=45bits) vmalloc/ioremap space +ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole +ffff810000000000 - ffffc0ffffffffff (=46 bits) direct mapping of all phys. memory +ffffc10000000000 - ffffc1ffffffffff (=40 bits) hole +ffffc20000000000 - ffffe1ffffffffff (=45 bits) vmalloc/ioremap space ... unused hole ... -ffffffff80000000 - ffffffff82800000 (=40MB) kernel text mapping, from phys 0 +ffffffff80000000 - ffffffff82800000 (=40 MB) kernel text mapping, from phys 0 ... unused hole ... -ffffffff88000000 - fffffffffff00000 (=1919MB) module mapping space +ffffffff88000000 - fffffffffff00000 (=1919 MB) module mapping space -The direct mapping covers all memory in the system upto the highest +The direct mapping covers all memory in the system up to the highest memory address (this means in some cases it can also include PCI memory -holes) +holes). vmalloc space is lazily synchronized into the different PML4 pages of the processes using the page fault handler, with init_level4_pgt as reference. -Current X86-64 implementations only support 40 bit of address space, -but we support upto 46bits. This expands into MBZ space in the page tables. +Current X86-64 implementations only support 40 bits of address space, +but we support up to 46 bits. This expands into MBZ space in the page tables. -Andi Kleen, Jul 2004 |