diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-ibft | 23 | ||||
| -rw-r--r-- | Documentation/DocBook/kernel-api.tmpl | 5 | ||||
| -rw-r--r-- | Documentation/DocBook/kernel-locking.tmpl | 6 | ||||
| -rw-r--r-- | Documentation/cpusets.txt | 72 | ||||
| -rw-r--r-- | Documentation/feature-removal-schedule.txt | 15 | ||||
| -rw-r--r-- | Documentation/filesystems/sysfs.txt | 9 | ||||
| -rw-r--r-- | Documentation/firmware_class/firmware_sample_driver.c | 115 | ||||
| -rw-r--r-- | Documentation/firmware_class/firmware_sample_firmware_class.c | 207 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 12 | ||||
| -rw-r--r-- | Documentation/power/devices.txt | 5 | ||||
| -rw-r--r-- | Documentation/powerpc/booting-without-of.txt | 622 | ||||
| -rw-r--r-- | Documentation/powerpc/phyp-assisted-dump.txt | 127 | ||||
| -rw-r--r-- | Documentation/prctl/disable-tsc-ctxt-sw-stress-test.c | 96 | ||||
| -rw-r--r-- | Documentation/prctl/disable-tsc-on-off-stress-test.c | 95 | ||||
| -rw-r--r-- | Documentation/prctl/disable-tsc-test.c | 94 | ||||
| -rw-r--r-- | Documentation/scheduler/sched-rt-group.txt | 188 |
16 files changed, 1298 insertions, 393 deletions
diff --git a/Documentation/ABI/testing/sysfs-ibft b/Documentation/ABI/testing/sysfs-ibft new file mode 100644 index 000000000000..c2b7d1154bec --- /dev/null +++ b/Documentation/ABI/testing/sysfs-ibft @@ -0,0 +1,23 @@ +What: /sys/firmware/ibft/initiator +Date: November 2007 +Contact: Konrad Rzeszutek <ketuzsezr@darnok.org> +Description: The /sys/firmware/ibft/initiator directory will contain + files that expose the iSCSI Boot Firmware Table initiator data. + Usually this contains the Initiator name. + +What: /sys/firmware/ibft/targetX +Date: November 2007 +Contact: Konrad Rzeszutek <ketuzsezr@darnok.org> +Description: The /sys/firmware/ibft/targetX directory will contain + files that expose the iSCSI Boot Firmware Table target data. + Usually this contains the target's IP address, boot LUN, + target name, and what NIC it is associated with. It can also + contain the CHAP name (and password), the reverse CHAP + name (and password) + +What: /sys/firmware/ibft/ethernetX +Date: November 2007 +Contact: Konrad Rzeszutek <ketuzsezr@darnok.org> +Description: The /sys/firmware/ibft/ethernetX directory will contain + files that expose the iSCSI Boot Firmware Table NIC data. + This can this can the IP address, MAC, and gateway of the NIC. diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl index dc0f30c3e571..488dd4a4945b 100644 --- a/Documentation/DocBook/kernel-api.tmpl +++ b/Documentation/DocBook/kernel-api.tmpl @@ -297,11 +297,6 @@ X!Earch/x86/kernel/mca_32.c !Ikernel/acct.c </chapter> - <chapter id="pmfuncs"> - <title>Power Management</title> -!Ekernel/power/pm.c - </chapter> - <chapter id="devdrivers"> <title>Device drivers infrastructure</title> <sect1><title>Device Drivers Base</title> diff --git a/Documentation/DocBook/kernel-locking.tmpl b/Documentation/DocBook/kernel-locking.tmpl index 2e9d6b41f034..435413ca40dc 100644 --- a/Documentation/DocBook/kernel-locking.tmpl +++ b/Documentation/DocBook/kernel-locking.tmpl @@ -241,7 +241,7 @@ </para> <para> The third type is a semaphore - (<filename class="headerfile">include/asm/semaphore.h</filename>): it + (<filename class="headerfile">include/linux/semaphore.h</filename>): it can have more than one holder at any time (the number decided at initialization time), although it is most commonly used as a single-holder lock (a mutex). If you can't get a semaphore, your @@ -290,7 +290,7 @@ <para> If you have a data structure which is only ever accessed from user context, then you can use a simple semaphore - (<filename>linux/asm/semaphore.h</filename>) to protect it. This + (<filename>linux/linux/semaphore.h</filename>) to protect it. This is the most trivial case: you initialize the semaphore to the number of resources available (usually 1), and call <function>down_interruptible()</function> to grab the semaphore, and @@ -1656,7 +1656,7 @@ the amount of locking which needs to be done. #include <linux/slab.h> #include <linux/string.h> +#include <linux/rcupdate.h> - #include <asm/semaphore.h> + #include <linux/semaphore.h> #include <asm/errno.h> struct object diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt index ad2bb3b3acc1..aa854b9b18cd 100644 --- a/Documentation/cpusets.txt +++ b/Documentation/cpusets.txt @@ -8,6 +8,7 @@ Portions Copyright (c) 2004-2006 Silicon Graphics, Inc. Modified by Paul Jackson <pj@sgi.com> Modified by Christoph Lameter <clameter@sgi.com> Modified by Paul Menage <menage@google.com> +Modified by Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> CONTENTS: ========= @@ -20,7 +21,8 @@ CONTENTS: 1.5 What is memory_pressure ? 1.6 What is memory spread ? 1.7 What is sched_load_balance ? - 1.8 How do I use cpusets ? + 1.8 What is sched_relax_domain_level ? + 1.9 How do I use cpusets ? 2. Usage Examples and Syntax 2.1 Basic Usage 2.2 Adding/removing cpus @@ -497,7 +499,73 @@ the cpuset code to update these sched domains, it compares the new partition requested with the current, and updates its sched domains, removing the old and adding the new, for each change. -1.8 How do I use cpusets ? + +1.8 What is sched_relax_domain_level ? +-------------------------------------- + +In sched domain, the scheduler migrates tasks in 2 ways; periodic load +balance on tick, and at time of some schedule events. + +When a task is woken up, scheduler try to move the task on idle CPU. +For example, if a task A running on CPU X activates another task B +on the same CPU X, and if CPU Y is X's sibling and performing idle, +then scheduler migrate task B to CPU Y so that task B can start on +CPU Y without waiting task A on CPU X. + +And if a CPU run out of tasks in its runqueue, the CPU try to pull +extra tasks from other busy CPUs to help them before it is going to +be idle. + +Of course it takes some searching cost to find movable tasks and/or +idle CPUs, the scheduler might not search all CPUs in the domain +everytime. In fact, in some architectures, the searching ranges on +events are limited in the same socket or node where the CPU locates, +while the load balance on tick searchs all. + +For example, assume CPU Z is relatively far from CPU X. Even if CPU Z +is idle while CPU X and the siblings are busy, scheduler can't migrate +woken task B from X to Z since it is out of its searching range. +As the result, task B on CPU X need to wait task A or wait load balance +on the next tick. For some applications in special situation, waiting +1 tick may be too long. + +The 'sched_relax_domain_level' file allows you to request changing +this searching range as you like. This file takes int value which +indicates size of searching range in levels ideally as follows, +otherwise initial value -1 that indicates the cpuset has no request. + + -1 : no request. use system default or follow request of others. + 0 : no search. + 1 : search siblings (hyperthreads in a core). + 2 : search cores in a package. + 3 : search cpus in a node [= system wide on non-NUMA system] + ( 4 : search nodes in a chunk of node [on NUMA system] ) + ( 5~ : search system wide [on NUMA system]) + +This file is per-cpuset and affect the sched domain where the cpuset +belongs to. Therefore if the flag 'sched_load_balance' of a cpuset +is disabled, then 'sched_relax_domain_level' have no effect since +there is no sched domain belonging the cpuset. + +If multiple cpusets are overlapping and hence they form a single sched +domain, the largest value among those is used. Be careful, if one +requests 0 and others are -1 then 0 is used. + +Note that modifying this file will have both good and bad effects, +and whether it is acceptable or not will be depend on your situation. +Don't modify this file if you are not sure. + +If your situation is: + - The migration costs between each cpu can be assumed considerably + small(for you) due to your special application's behavior or + special hardware support for CPU cache etc. + - The searching cost doesn't have impact(for you) or you can make + the searching cost enough small by managing cpuset to compact etc. + - The latency is required even it sacrifices cache hit rate etc. +then increasing 'sched_relax_domain_level' would benefit you. + + +1.9 How do I use cpusets ? -------------------------- In order to minimize the impact of cpusets on critical kernel diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index af0e9393bf68..b45ea28abc99 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -282,6 +282,13 @@ Why: Not used in-tree. The current out-of-tree users used it to out-of-tree driver. Who: Thomas Gleixner <tglx@linutronix.de> +---------------------------- + +What: usedac i386 kernel parameter +When: 2.6.27 +Why: replaced by allowdac and no dac combination +Who: Glauber Costa <gcosta@redhat.com> + --------------------------- What: /sys/o2cb symlink @@ -291,3 +298,11 @@ Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb ocfs2-tools. 2 years should be sufficient time to phase in new versions which know to look in /sys/fs/o2cb. Who: ocfs2-devel@oss.oracle.com + +--------------------------- + +What: asm/semaphore.h +When: 2.6.26 +Why: Implementation became generic; users should now include + linux/semaphore.h instead. +Who: Matthew Wilcox <willy@linux.intel.com> diff --git a/Documentation/filesystems/sysfs.txt b/Documentation/filesystems/sysfs.txt index 4598ef7b622b..7f27b8f840d0 100644 --- a/Documentation/filesystems/sysfs.txt +++ b/Documentation/filesystems/sysfs.txt @@ -176,8 +176,10 @@ implementations: Recall that an attribute should only be exporting one value, or an array of similar values, so this shouldn't be that expensive. - This allows userspace to do partial reads and seeks arbitrarily over - the entire file at will. + This allows userspace to do partial reads and forward seeks + arbitrarily over the entire file at will. If userspace seeks back to + zero or does a pread(2) with an offset of '0' the show() method will + be called again, rearmed, to fill the buffer. - On write(2), sysfs expects the entire buffer to be passed during the first write. Sysfs then passes the entire buffer to the store() @@ -192,6 +194,9 @@ implementations: Other notes: +- Writing causes the show() method to be rearmed regardless of current + file position. + - The buffer will always be PAGE_SIZE bytes in length. On i386, this is 4096. diff --git a/Documentation/firmware_class/firmware_sample_driver.c b/Documentation/firmware_class/firmware_sample_driver.c deleted file mode 100644 index 6865cbe075ec..000000000000 --- a/Documentation/firmware_class/firmware_sample_driver.c +++ /dev/null @@ -1,115 +0,0 @@ -/* - * firmware_sample_driver.c - - * - * Copyright (c) 2003 Manuel Estrada Sainz - * - * Sample code on how to use request_firmware() from drivers. - * - */ - -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/init.h> -#include <linux/device.h> -#include <linux/string.h> - -#include "linux/firmware.h" - -static struct device ghost_device = { - .bus_id = "ghost0", -}; - - -static void sample_firmware_load(char *firmware, int size) -{ - u8 buf[size+1]; - memcpy(buf, firmware, size); - buf[size] = '\0'; - printk(KERN_INFO "firmware_sample_driver: firmware: %s\n", buf); -} - -static void sample_probe_default(void) -{ - /* uses the default method to get the firmware */ - const struct firmware *fw_entry; - printk(KERN_INFO "firmware_sample_driver: a ghost device got inserted :)\n"); - - if(request_firmware(&fw_entry, "sample_driver_fw", &ghost_device)!=0) - { - printk(KERN_ERR - "firmware_sample_driver: Firmware not available\n"); - return; - } - - sample_firmware_load(fw_entry->data, fw_entry->size); - - release_firmware(fw_entry); - - /* finish setting up the device */ -} -static void sample_probe_specific(void) -{ - /* Uses some specific hotplug support to get the firmware from - * userspace directly into the hardware, or via some sysfs file */ - - /* NOTE: This currently doesn't work */ - - printk(KERN_INFO "firmware_sample_driver: a ghost device got inserted :)\n"); - - if(request_firmware(NULL, "sample_driver_fw", &ghost_device)!=0) - { - printk(KERN_ERR - "firmware_sample_driver: Firmware load failed\n"); - return; - } - - /* request_firmware blocks until userspace finished, so at - * this point the firmware should be already in the device */ - - /* finish setting up the device */ -} -static void sample_probe_async_cont(const struct firmware *fw, void *context) -{ - if(!fw){ - printk(KERN_ERR - "firmware_sample_driver: firmware load failed\n"); - return; - } - - printk(KERN_INFO "firmware_sample_driver: device pointer \"%s\"\n", - (char *)context); - sample_firmware_load(fw->data, fw->size); -} -static void sample_probe_async(void) -{ - /* Let's say that I can't sleep */ - int error; - error = request_firmware_nowait (THIS_MODULE, FW_ACTION_NOHOTPLUG, - "sample_driver_fw", &ghost_device, - "my device pointer", - sample_probe_async_cont); - if(error){ - printk(KERN_ERR - "firmware_sample_driver:" - " request_firmware_nowait failed\n"); - } -} - -static int sample_init(void) -{ - device_initialize(&ghost_device); - /* since there is no real hardware insertion I just call the - * sample probe functions here */ - sample_probe_specific(); - sample_probe_default(); - sample_probe_async(); - return 0; -} -static void __exit sample_exit(void) -{ -} - -module_init (sample_init); -module_exit (sample_exit); - -MODULE_LICENSE("GPL"); diff --git a/Documentation/firmware_class/firmware_sample_firmware_class.c b/Documentation/firmware_class/firmware_sample_firmware_class.c deleted file mode 100644 index 2de62854f0e5..000000000000 --- a/Documentation/firmware_class/firmware_sample_firmware_class.c +++ /dev/null @@ -1,207 +0,0 @@ -/* - * firmware_sample_firmware_class.c - - * - * Copyright (c) 2003 Manuel Estrada Sainz - * - * NOTE: This is just a probe of concept, if you think that your driver would - * be well served by this mechanism please contact me first. - * - * DON'T USE THIS CODE AS IS - * - */ - -#include <linux/device.h> -#include <linux/module.h> -#include <linux/init.h> -#include <linux/timer.h> -#include <linux/slab.h> -#include <linux/string.h> -#include <linux/firmware.h> - - -MODULE_AUTHOR("Manuel Estrada Sainz"); -MODULE_DESCRIPTION("Hackish sample for using firmware class directly"); -MODULE_LICENSE("GPL"); - -static inline struct class_device *to_class_dev(struct kobject *obj) -{ - return container_of(obj,struct class_device,kobj); -} -static inline -struct class_device_attribute *to_class_dev_attr(struct attribute *_attr) -{ - return container_of(_attr,struct class_device_attribute,attr); -} - -int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr); -int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr); - -struct firmware_priv { - char fw_id[FIRMWARE_NAME_MAX]; - s32 loading:2; - u32 abort:1; -}; - -extern struct class firmware_class; - -static ssize_t firmware_loading_show(struct class_device *class_dev, char *buf) -{ - struct firmware_priv *fw_priv = class_get_devdata(class_dev); - return sprintf(buf, "%d\n", fw_priv->loading); -} -static ssize_t firmware_loading_store(struct class_device *class_dev, - const char *buf, size_t count) -{ - struct firmware_priv *fw_priv = class_get_devdata(class_dev); - int prev_loading = fw_priv->loading; - - fw_priv->loading = simple_strtol(buf, NULL, 10); - - switch(fw_priv->loading){ - case -1: - /* abort load an panic */ - break; - case 1: - /* setup load */ - break; - case 0: - if(prev_loading==1){ - /* finish load and get the device back to working - * state */ - } - break; - } - - return count; -} -static CLASS_DEVICE_ATTR(loading, 0644, - firmware_loading_show, firmware_loading_store); - -static ssize_t firmware_data_read(struct kobject *kobj, - struct bin_attribute *bin_attr, - char *buffer, loff_t offset, size_t count) -{ - struct class_device *class_dev = to_class_dev(kobj); - struct firmware_priv *fw_priv = class_get_devdata(class_dev); - - /* read from the devices firmware memory */ - - return count; -} -static ssize_t firmware_data_write(struct kobject *kobj, - struct bin_attribute *bin_attr, - char *buffer, loff_t offset, size_t count) -{ - struct class_device *class_dev = to_class_dev(kobj); - struct firmware_priv *fw_priv = class_get_devdata(class_dev); - - /* write to the devices firmware memory */ - - return count; -} -static struct bin_attribute firmware_attr_data = { - .attr = {.name = "data", .mode = 0644}, - .size = 0, - .read = firmware_data_read, - .write = firmware_data_write, -}; -static int fw_setup_class_device(struct class_device *class_dev, - const char *fw_name, - struct device *device) -{ - int retval; - struct firmware_priv *fw_priv; - - fw_priv = kzalloc(sizeof(struct firmware_priv), GFP_KERNEL); - if (!fw_priv) { - retval = -ENOMEM; - goto out; - } - - memset(class_dev, 0, sizeof(*class_dev)); - - strncpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX); - fw_priv->fw_id[FIRMWARE_NAME_MAX-1] = '\0'; - - strncpy(class_dev->class_id, device->bus_id, BUS_ID_SIZE); - class_dev->class_id[BUS_ID_SIZE-1] = '\0'; - class_dev->dev = device; - - class_dev->class = &firmware_class, - class_set_devdata(class_dev, fw_priv); - retval = class_device_register(class_dev); - if (retval){ - printk(KERN_ERR "%s: class_device_register failed\n", - __FUNCTION__); - goto error_free_fw_priv; - } - - retval = sysfs_create_bin_file(&class_dev->kobj, &firmware_attr_data); - if (retval){ - printk(KERN_ERR "%s: sysfs_create_bin_file failed\n", - __FUNCTION__); - goto error_unreg_class_dev; - } - - retval = class_device_create_file(class_dev, - &class_device_attr_loading); - if (retval){ - printk(KERN_ERR "%s: class_device_create_file failed\n", - __FUNCTION__); - goto error_remove_data; - } - - goto out; - -error_remove_data: - sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data); -error_unreg_class_dev: - class_device_unregister(class_dev); -error_free_fw_priv: - kfree(fw_priv); -out: - return retval; -} -static void fw_remove_class_device(struct class_device *class_dev) -{ - struct firmware_priv *fw_priv = class_get_devdata(class_dev); - - class_device_remove_file(class_dev, &class_device_attr_loading); - sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data); - class_device_unregister(class_dev); -} - -static struct class_device *class_dev; - -static struct device my_device = { - .bus_id = "my_dev0", -}; - -static int __init firmware_sample_init(void) -{ - int error; - - device_initialize(&my_device); - class_dev = kmalloc(sizeof(struct class_device), GFP_KERNEL); - if(!class_dev) - return -ENOMEM; - - error = fw_setup_class_device(class_dev, "my_firmware_image", - &my_device); - if(error){ - kfree(class_dev); - return error; - } - return 0; - -} -static void __exit firmware_sample_exit(void) -{ - struct firmware_priv *fw_priv = class_get_devdata(class_dev); - fw_remove_class_device(class_dev); - kfree(fw_priv); - kfree(class_dev); -} -module_init(firmware_sample_init); -module_exit(firmware_sample_exit); - diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4b0f1ae31a4c..dfb5bef24013 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -954,6 +954,8 @@ and is between 256 and 4096 characters. It is defined in the file l2cr= [PPC] + l3cr= [PPC] + lapic [X86-32,APIC] Enable the local APIC even if BIOS disabled it. @@ -1280,8 +1282,16 @@ and is between 256 and 4096 characters. It is defined in the file noexec [IA-64] noexec [X86-32,X86-64] + On X86-32 available only on PAE configured kernels. noexec=on: enable non-executable mappings (default) - noexec=off: disable nn-executable mappings + noexec=off: disable non-executable mappings + + noexec32 [X86-64] + This affects only 32-bit executables. + noexec32=on: enable non-executable mappings (default) + read doesn't imply executable mappings + noexec32=off: disable non-executable mappings + read implies executable mappings nofxsr [BUGS=X86-32] Disables x86 floating point extended register save and restore. The kernel will only save diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index 461e4f1dbec4..421e7d00ffd0 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt @@ -196,6 +196,11 @@ its parent; and can't be removed or suspended after that parent. The policy is that the device tree should match hardware bus topology. (Or at least the control bus, for devices which use multiple busses.) +In particular, this means that a device registration may fail if the parent of +the device is suspending (ie. has been chosen by the PM core as the next +device to suspend) or has already suspended, as well as after all of the other +devices have been suspended. Device drivers must be prepared to cope with such +situations. Suspending Devices diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt index 7b4e8a70882c..4cc780024e6c 100644 --- a/Documentation/powerpc/booting-without-of.txt +++ b/Documentation/powerpc/booting-without-of.txt @@ -59,12 +59,39 @@ Table of Contents p) Freescale Synchronous Serial Interface q) USB EHCI controllers - VII - Specifying interrupt information for devices + VII - Marvell Discovery mv64[345]6x System Controller chips + 1) The /system-controller node + 2) Child nodes of /system-controller + a) Marvell Discovery MDIO bus + b) Marvell Discovery ethernet controller + c) Marvell Discovery PHY nodes + d) Marvell Discovery SDMA nodes + e) Marvell Discovery BRG nodes + f) Marvell Discovery CUNIT nodes + g) Marvell Discovery MPSCROUTING nodes + h) Marvell Discovery MPSCINTR nodes + i) Marvell Discovery MPSC nodes + j) Marvell Discovery Watch Dog Timer nodes + k) Marvell Discovery I2C nodes + l) Marvell Discovery PIC (Programmable Interrupt Controller) nodes + m) Marvell Discovery MPP (Multipurpose Pins) multiplexing nodes + n) Marvell Discovery GPP (General Purpose Pins) nodes + o) Marvell Discovery PCI host bridge node + p) Marvell Discovery CPU Error nodes + q) Marvell Discovery SRAM Controller nodes + r) Marvell Discovery PCI Error Handler nodes + s) Marvell Discovery Memory Controller nodes + + VIII - Specifying interrupt information for devices 1) interrupts property 2) interrupt-parent property 3) OpenPIC Interrupt Controllers 4) ISA Interrupt Controllers + VIII - Specifying GPIO information for devices + 1) gpios property + 2) gpio-controller nodes + Appendix A - Sample SOC node for MPC8540 @@ -1269,10 +1296,6 @@ platforms are moved over to use the flattened-device-tree model. Recommended properties: - - linux,network-index : This is the intended "index" of this - network device. This is used by the bootwrapper to interpret - MAC addresses passed by the firmware when no information other - than indices is available to associate an address with a device. - phy-connection-type : a string naming the controller/PHY interface type, i.e., "mii" (default), "rmii", "gmii", "rgmii", "rgmii-id", "sgmii", "tbi", or "rtbi". This property is only really needed if the connection @@ -1622,8 +1645,7 @@ platforms are moved over to use the flattened-device-tree model. - device_type : should be "network", "hldc", "uart", "transparent" "bisync", "atm", or "serial". - compatible : could be "ucc_geth" or "fsl_atm" and so on. - - model : should be "UCC". - - device-id : the ucc number(1-8), corresponding to UCCx in UM. + - cell-index : the ucc number(1-8), corresponding to UCCx in UM. - reg : Offset and length of the register set for the device - interrupts : <a b> where a is the interrupt number and b is a field that represents an encoding of the sense and level @@ -1667,10 +1689,6 @@ platforms are moved over to use the flattened-device-tree model. - phy-handle : The phandle for the PHY connected to this controller. Recommended properties: - - linux,network-index : This is the intended "index" of this - network device. This is used by the bootwrapper to interpret - MAC addresses passed by the firmware when no information other - than indices is available to associate an address with a device. - phy-connection-type : a string naming the controller/PHY interface type, i.e., "mii" (default), "rmii", "gmii", "rgmii", "rgmii-id" (Internal Delay), "rgmii-txid" (delay on TX only), "rgmii-rxid" (delay on RX only), @@ -1680,8 +1698,7 @@ platforms are moved over to use the flattened-device-tree model. ucc@2000 { device_type = "network"; compatible = "ucc_geth"; - model = "UCC"; - device-id = <1>; + cell-index = <1>; reg = <2000 200>; interrupts = <a0 0>; interrupt-parent = <700>; @@ -1995,7 +2012,6 @@ platforms are moved over to use the flattened-device-tree model. interrupts = <20 8>; interrupt-parent = <&PIC>; phy-handle = <&PHY0>; - linux,network-index = <0>; fsl,cpm-command = <12000300>; }; @@ -2217,12 +2233,6 @@ platforms are moved over to use the flattened-device-tree model. EMAC, that is the content of the current (bogus) "phy-port" property. - Recommended properties: - - linux,network-index : This is the intended "index" of this - network device. This is used by the bootwrapper to interpret - MAC addresses passed by the firmware when no information other - than indices is available to associate an address with a device. - Optional properties: - phy-address : 1 cell, optional, MDIO address of the PHY. If absent, a search is performed. @@ -2246,7 +2256,6 @@ platforms are moved over to use the flattened-device-tree model. Example: EMAC0: ethernet@40000800 { - linux,network-index = <0>; device_type = "network"; compatible = "ibm,emac-440gp", "ibm,emac"; interrupt-parent = <&UIC1>; @@ -2817,9 +2826,528 @@ platforms are moved over to use the flattened-device-tree model. }; - More devices will be defined as this spec matures. +VII - Marvell Discovery mv64[345]6x System Controller chips +=========================================================== + +The Marvell mv64[345]60 series of system controller chips contain +many of the peripherals needed to implement a complete computer +system. In this section, we define device tree nodes to describe +the system controller chip itself and each of the peripherals +which it contains. Compatible string values for each node are +prefixed with the string "marvell,", for Marvell Technology Group Ltd. + +1) The /system-controller node + + This node is used to represent the system-controller and must be + present when the system uses a system contller chip. The top-level + system-controller node contains information that is global to all + devices within the system controller chip. The node name begins + with "system-controller" followed by the unit address, which is + the base address of the memory-mapped register set for the system + controller chip. + + Required properties: + + - ranges : Describes the translation of system controller addresses + for memory mapped registers. + - clock-frequency: Contains the main clock frequency for the system + controller chip. + - reg : This property defines the address and size of the + memory-mapped registers contained within the system controller + chip. The address specified in the "reg" property should match + the unit address of the system-controller node. + - #address-cells : Address representation for system controller + devices. This field represents the number of cells needed to + represent the address of the memory-mapped registers of devices + within the system controller chip. + - #size-cells : Size representation for for the memory-mapped + registers within the system controller chip. + - #interrupt-cells : Defines the width of cells used to represent + interrupts. + + Optional properties: + + - model : The specific model of the system controller chip. Such + as, "mv64360", "mv64460", or "mv64560". + - compatible : A string identifying the compatibility identifiers + of the system controller chip. + + The system-controller node contains child nodes for each system + controller device that the platform uses. Nodes should not be created + for devices which exist on the system controller chip but are not used + + Example Marvell Discovery mv64360 system-controller node: + + system-controller@f1000000 { /* Marvell Discovery mv64360 */ + #address-cells = <1>; + #size-cells = <1>; + model = "mv64360"; /* Default */ + compatible = "marvell,mv64360"; + clock-frequency = <133333333>; + reg = <0xf1000000 0x10000>; + virtual-reg = <0xf1000000>; + ranges = <0x88000000 0x88000000 0x1000000 /* PCI 0 I/O Space */ + 0x80000000 0x80000000 0x8000000 /* PCI 0 MEM Space */ + 0xa0000000 0xa0000000 0x4000000 /* User FLASH */ + 0x00000000 0xf1000000 0x0010000 /* Bridge's regs */ + 0xf2000000 0xf2000000 0x0040000>;/* Integrated SRAM */ + + [ child node definitions... ] + } + +2) Child nodes of /system-controller + + a) Marvell Discovery MDIO bus + + The MDIO is a bus to which the PHY devices are connected. For each + device that exists on this bus, a child node should be created. See + the definition of the PHY node below for an example of how to define + a PHY. + + Required properties: + - #address-cells : Should be <1> + - #size-cells : Should be <0> + - device_type : Should be "mdio" + - compatible : Should be "marvell,mv64360-mdio" + + Example: + + mdio { + #address-cells = <1>; + #size-cells = <0>; + device_type = "mdio"; + compatible = "marvell,mv64360-mdio"; + + ethernet-phy@0 { + ...... + }; + }; + + + b) Marvell Discovery ethernet controller + + The Discover ethernet controller is described with two levels + of nodes. The first level describes an ethernet silicon block + and the second level describes up to 3 ethernet nodes within + that block. The reason for the multiple levels is that the + registers for the node are interleaved within a single set + of registers. The "ethernet-block" level describes the + shared register set, and the "ethernet" nodes describe ethernet + port-specific properties. + + Ethernet block node + + Required properties: + - #address-cells : <1> + - #size-cells : <0> + - compatible : "marvell,mv64360-eth-block" + - reg : Offset and length of the register set for this block + + Example Discovery Ethernet block node: + ethernet-block@2000 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "marvell,mv64360-eth-block"; + reg = <0x2000 0x2000>; + ethernet@0 { + ....... + }; + }; + + Ethernet port node + + Required properties: + - device_type : Should be "network". + - compatible : Should be "marvell,mv64360-eth". + - reg : Should be <0>, <1>, or <2>, according to which registers + within the silicon block the device uses. + - interrupts : <a> where a is the interrupt number for the port. + - interrupt-parent : the phandle for the interrupt controller + that services interrupts for this device. + - phy : the phandle for the PHY connected to this ethernet + controller. + - local-mac-address : 6 bytes, MAC address + + Example Discovery Ethernet port node: + ethernet@0 { + device_type = "network"; + compatible = "marvell,mv64360-eth"; + reg = <0>; + interrupts = <32>; + interrupt-parent = <&PIC>; + phy = <&PHY0>; + local-mac-address = [ 00 00 00 00 00 00 ]; + }; + + + + c) Marvell Discovery PHY nodes + + Required properties: + - device_type : Should be "ethernet-phy" + - interrupts : <a> where a is the interrupt number for this phy. + - interrupt-parent : the phandle for the interrupt controller that + services interrupts for this device. + - reg : The ID number for the phy, usually a small integer + + Example Discovery PHY node: + ethernet-phy@1 { + device_type = "ethernet-phy"; + compatible = "broadcom,bcm5421"; + interrupts = <76>; /* GPP 12 */ + interrupt-parent = <&PIC>; + reg = <1>; + }; + + + d) Marvell Discovery SDMA nodes + + Represent DMA hardware associated with the MPSC (multiprotocol + serial controllers). + + Required properties: + - compatible : "marvell,mv64360-sdma" + - reg : Offset and length of the register set for this device + - interrupts : <a> where a is the interrupt number for the DMA + device. + - interrupt-parent : the phandle for the interrupt controller + that services interrupts for this device. + + Example Discovery SDMA node: + sdma@4000 { + compatible = "marvell,mv64360-sdma"; + reg = <0x4000 0xc18>; + virtual-reg = <0xf1004000>; + interrupts = <36>; + interrupt-parent = <&PIC>; + }; + + + e) Marvell Discovery BRG nodes + + Represent baud rate generator hardware associated with the MPSC + (multiprotocol serial controllers). + + Required properties: + - compatible : "marvell,mv64360-brg" + - reg : Offset and length of the register set for this device + - clock-src : A value from 0 to 15 which selects the clock + source for the baud rate generator. This value corresponds + to the CLKS value in the BRGx configuration register. See + the mv64x60 User's Manual. + - clock-frequence : The frequency (in Hz) of the baud rate + generator's input clock. + - current-speed : The current speed setting (presumably by + firmware) of the baud rate generator. + + Example Discovery BRG node: + brg@b200 { + compatible = "marvell,mv64360-brg"; + reg = <0xb200 0x8>; + clock-src = <8>; + clock-frequency = <133333333>; + current-speed = <9600>; + }; + + + f) Marvell Discovery CUNIT nodes + + Represent the Serial Communications Unit device hardware. + + Required properties: + - reg : Offset and length of the register set for this device + + Example Discovery CUNIT node: + cunit@f200 { + reg = <0xf200 0x200>; + }; + + + g) Marvell Discovery MPSCROUTING nodes + + Represent the Discovery's MPSC routing hardware + + Required properties: + - reg : Offset and length of the register set for this device + + Example Discovery CUNIT node: + mpscrouting@b500 { + reg = <0xb400 0xc>; + }; + + + h) Marvell Discovery MPSCINTR nodes + + Represent the Discovery's MPSC DMA interrupt hardware registers + (SDMA cause and mask registers). + + Required properties: + - reg : Offset and length of the register set for this device -VII - Specifying interrupt information for devices + Example Discovery MPSCINTR node: + mpsintr@b800 { + reg = <0xb800 0x100>; + }; + + + i) Marvell Discovery MPSC nodes + + Represent the Discovery's MPSC (Multiprotocol Serial Controller) + serial port. + + Required properties: + - device_type : "serial" + - compatible : "marvell,mv64360-mpsc" + - reg : Offset and length of the register set for this device + - sdma : the phandle for the SDMA node used by this port + - brg : the phandle for the BRG node used by this port + - cunit : the phandle for the CUNIT node used by this port + - mpscrouting : the phandle for the MPSCROUTING node used by this port + - mpscintr : the phandle for the MPSCINTR node used by this port + - cell-index : the hardware index of this cell in the MPSC core + - max_idle : value needed for MPSC CHR3 (Maximum Frame Length) + register + - interrupts : <a> where a is the interrupt number for the MPSC. + - interrupt-parent : the phandle for the interrupt controller + that services interrupts for this device. + + Example Discovery MPSCINTR node: + mpsc@8000 { + device_type = "serial"; + compatible = "marvell,mv64360-mpsc"; + reg = <0x8000 0x38>; + virtual-reg = <0xf1008000>; + sdma = <&SDMA0>; + brg = <&BRG0>; + cunit = <&CUNIT>; + mpscrouting = <&MPSCROUTING>; + mpscintr = <&MPSCINTR>; + cell-index = <0>; + max_idle = <40>; + interrupts = <40>; + interrupt-parent = <&PIC>; + }; + + + j) Marvell Discovery Watch Dog Timer nodes + + Represent the Discovery's watchdog timer hardware + + Required properties: + - compatible : "marvell,mv64360-wdt" + - reg : Offset and length of the register set for this device + + Example Discovery Watch Dog Timer node: + wdt@b410 { + compatible = "marvell,mv64360-wdt"; + reg = <0xb410 0x8>; + }; + + + k) Marvell Discovery I2C nodes + + Represent the Discovery's I2C hardware + + Required properties: + - device_type : "i2c" + - compatible : "marvell,mv64360-i2c" + - reg : Offset and length of the register set for this device + - interrupts : <a> where a is the interrupt number for the I2C. + - interrupt-parent : the phandle for the interrupt controller + that services interrupts for this device. + + Example Discovery I2C node: + compatible = "marvell,mv64360-i2c"; + reg = <0xc000 0x20>; + virtual-reg = <0xf100c000>; + interrupts = <37>; + interrupt-parent = <&PIC>; + }; + + + l) Marvell Discovery PIC (Programmable Interrupt Controller) nodes + + Represent the Discovery's PIC hardware + + Required properties: + - #interrupt-cells : <1> + - #address-cells : <0> + - compatible : "marvell,mv64360-pic" + - reg : Offset and length of the register set for this device + - interrupt-controller + + Example Discovery PIC node: + pic { + #interrupt-cells = <1>; + #address-cells = <0>; + compatible = "marvell,mv64360-pic"; + reg = <0x0 0x88>; + interrupt-controller; + }; + + + m) Marvell Discovery MPP (Multipurpose Pins) multiplexing nodes + + Represent the Discovery's MPP hardware + + Required properties: + - compatible : "marvell,mv64360-mpp" + - reg : Offset and length of the register set for this device + + Example Discovery MPP node: + mpp@f000 { + compatible = "marvell,mv64360-mpp"; + reg = <0xf000 0x10>; + }; + + + n) Marvell Discovery GPP (General Purpose Pins) nodes + + Represent the Discovery's GPP hardware + + Required properties: + - compatible : "marvell,mv64360-gpp" + - reg : Offset and length of the register set for this device + + Example Discovery GPP node: + gpp@f000 { + compatible = "marvell,mv64360-gpp"; + reg = <0xf100 0x20>; + }; + + + o) Marvell Discovery PCI host bridge node + + Represents the Discovery's PCI host bridge device. The properties + for this node conform to Rev 2.1 of the PCI Bus Binding to IEEE + 1275-1994. A typical value for the compatible property is + "marvell,mv64360-pci". + + Example Discovery PCI host bridge node + pci@80000000 { + #address-cells = <3>; + #size-cells = <2>; + #interrupt-cells = <1>; + device_type = "pci"; + compatible = "marvell,mv64360-pci"; + reg = <0xcf8 0x8>; + ranges = <0x01000000 0x0 0x0 + 0x88000000 0x0 0x01000000 + 0x02000000 0x0 0x80000000 + 0x80000000 0x0 0x08000000>; + bus-range = <0 255>; + clock-frequency = <66000000>; + interrupt-parent = <&PIC>; + interrupt-map-mask = <0xf800 0x0 0x0 0x7>; + interrupt-map = < + /* IDSEL 0x0a */ + 0x5000 0 0 1 &PIC 80 + 0x5000 0 0 2 &PIC 81 + 0x5000 0 0 3 &PIC 91 + 0x5000 0 0 4 &PIC 93 + + /* IDSEL 0x0b */ + 0x5800 0 0 1 &PIC 91 + 0x5800 0 0 2 &PIC 93 + 0x5800 0 0 3 &PIC 80 + 0x5800 0 0 4 &PIC 81 + + /* IDSEL 0x0c */ + 0x6000 0 0 1 &PIC 91 + 0x6000 0 0 2 &PIC 93 + 0x6000 0 0 3 &PIC 80 + 0x6000 0 0 4 &PIC 81 + + /* IDSEL 0x0d */ + 0x6800 0 0 1 &PIC 93 + 0x6800 0 0 2 &PIC 80 + 0x6800 0 0 3 &PIC 81 + 0x6800 0 0 4 &PIC 91 + >; + }; + + + p) Marvell Discovery CPU Error nodes + + Represent the Discovery's CPU error handler device. + + Required properties: + - compatible : "marvell,mv64360-cpu-error" + - reg : Offset and length of the register set for this device + - interrupts : the interrupt number for this device + - interrupt-parent : the phandle for the interrupt controller + that services interrupts for this device. + + Example Discovery CPU Error node: + cpu-error@0070 { + compatible = "marvell,mv64360-cpu-error"; + reg = <0x70 0x10 0x128 0x28>; + interrupts = <3>; + interrupt-parent = <&PIC>; + }; + + + q) Marvell Discovery SRAM Controller nodes + + Represent the Discovery's SRAM controller device. + + Required properties: + - compatible : "marvell,mv64360-sram-ctrl" + - reg : Offset and length of the register set for this device + - interrupts : the interrupt number for this device + - interrupt-parent : the phandle for the interrupt controller + that services interrupts for this device. + + Example Discovery SRAM Controller node: + sram-ctrl@0380 { + compatible = "marvell,mv64360-sram-ctrl"; + reg = <0x380 0x80>; + interrupts = <13>; + interrupt-parent = <&PIC>; + }; + + + r) Marvell Discovery PCI Error Handler nodes + + Represent the Discovery's PCI error handler device. + + Required properties: + - compatible : "marvell,mv64360-pci-error" + - reg : Offset and length of the register set for this device + - interrupts : the interrupt number for this device + - interrupt-parent : the phandle for the interrupt controller + that services interrupts for this device. + + Example Discovery PCI Error Handler node: + pci-error@1d40 { + compatible = "marvell,mv64360-pci-error"; + reg = <0x1d40 0x40 0xc28 0x4>; + interrupts = <12>; + interrupt-parent = <&PIC>; + }; + + + s) Marvell Discovery Memory Controller nodes + + Represent the Discovery's memory controller device. + + Required properties: + - compatible : "marvell,mv64360-mem-ctrl" + - reg : Offset and length of the register set for this device + - interrupts : the interrupt number for this device + - interrupt-parent : the phandle for the interrupt controller + that services interrupts for this device. + + Example Discovery Memory Controller node: + mem-ctrl@1400 { + compatible = "marvell,mv64360-mem-ctrl"; + reg = <0x1400 0x60>; + interrupts = <17>; + interrupt-parent = <&PIC>; + }; + + +VIII - Specifying interrupt information for devices =================================================== The device tree represents the busses and devices of a hardware @@ -2905,6 +3433,54 @@ encodings listed below: 2 = high to low edge sensitive type enabled 3 = low to high edge sensitive type enabled +VIII - Specifying GPIO information for devices +============================================== + +1) gpios property +----------------- + +Nodes that makes use of GPIOs should define them using `gpios' property, +format of which is: <&gpio-controller1-phandle gpio1-specifier + &gpio-controller2-phandle gpio2-specifier + 0 /* holes are permitted, means no GPIO 3 */ + &gpio-controller4-phandle gpio4-specifier + ...>; + +Note that gpio-specifier length is controller dependent. + +gpio-specifier may encode: bank, pin position inside the bank, +whether pin is open-drain and whether pin is logically inverted. + +Example of the node using GPIOs: + + node { + gpios = <&qe_pio_e 18 0>; + }; + +In this example gpio-specifier is "18 0" and encodes GPIO pin number, +and empty GPIO flags as accepted by the "qe_pio_e" gpio-controller. + +2) gpio-controller nodes +------------------------ + +Every GPIO controller node must have #gpio-cells property defined, +this information will be used to translate gpio-specifiers. + +Example of two SOC GPIO banks defined as gpio-controller nodes: + + qe_pio_a: gpio-controller@1400 { + #gpio-cells = <2>; + compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank"; + reg = <0x1400 0x18>; + gpio-controller; + }; + + qe_pio_e: gpio-controller@1460 { + #gpio-cells = <2>; + compatible = "fsl,qe-pario-bank-e", "fsl,qe-pario-bank"; + reg = <0x1460 0x18>; + gpio-controller; + }; Appendix A - Sample SOC node for MPC8540 ======================================== diff --git a/Documentation/powerpc/phyp-assisted-dump.txt b/Documentation/powerpc/phyp-assisted-dump.txt new file mode 100644 index 000000000000..c4682b982a2e --- /dev/null +++ b/Documentation/powerpc/phyp-assisted-dump.txt @@ -0,0 +1,127 @@ + + Hypervisor-Assisted Dump + ------------------------ + November 2007 + +The goal of hypervisor-assisted dump is to enable the dump of +a crashed system, and to do so from a fully-reset system, and +to minimize the total elapsed time until the system is back +in production use. + +As compared to kdump or other strategies, hypervisor-assisted +dump offers several strong, practical advantages: + +-- Unlike kdump, the system has been reset, and loaded + with a fresh copy of the kernel. In particular, + PCI and I/O devices have been reinitialized and are + in a clean, consistent state. +-- As the dump is performed, the dumped memory becomes + immediately available to the system for normal use. +-- After the dump is completed, no further reboots are + required; the system will be fully usable, and running + in it's normal, production mode on it normal kernel. + +The above can only be accomplished by coordination with, +and assistance from the hypervisor. The procedure is +as follows: + +-- When a system crashes, the hypervisor will save + the low 256MB of RAM to a previously registered + save region. It will also save system state, system + registers, and hardware PTE's. + +-- After the low 256MB area has been saved, the + hypervisor will reset PCI and other hardware state. + It will *not* clear RAM. It will then launch the + bootloader, as normal. + +-- The freshly booted kernel will notice that there + is a new node (ibm,dump-kernel) in the device tree, + indicating that there is crash data available from + a previous boot. It will boot into only 256MB of RAM, + reserving the rest of system memory. + +-- Userspace tools will parse /sys/kernel/release_region + and read /proc/vmcore to obtain the contents of memory, + which holds the previous crashed kernel. The userspace + tools may copy this info to disk, or network, nas, san, + iscsi, etc. as desired. + + For Example: the values in /sys/kernel/release-region + would look something like this (address-range pairs). + CPU:0x177fee000-0x10000: HPTE:0x177ffe020-0x1000: / + DUMP:0x177fff020-0x10000000, 0x10000000-0x16F1D370A + +-- As the userspace tools complete saving a portion of + dump, they echo an offset and size to + /sys/kernel/release_region to release the reserved + memory back to general use. + + An example of this is: + "echo 0x40000000 0x10000000 > /sys/kernel/release_region" + which will release 256MB at the 1GB boundary. + +Please note that the hypervisor-assisted dump feature +is only available on Power6-based systems with recent +firmware versions. + +Implementation details: +---------------------- + +During boot, a check is made to see if firmware supports +this feature on this particular machine. If it does, then +we check to see if a active dump is waiting for us. If yes +then everything but 256 MB of RAM is reserved during early +boot. This area is released once we collect a dump from user +land scripts that are run. If there is dump data, then +the /sys/kernel/release_region file is created, and +the reserved memory is held. + +If there is no waiting dump data, then only the highest +256MB of the ram is reserved as a scratch area. This area +is *not* released: this region will be kept permanently +reserved, so that it can act as a receptacle for a copy +of the low 256MB in the case a crash does occur. See, +however, "open issues" below, as to whether +such a reserved region is really needed. + +Currently the dump will be copied from /proc/vmcore to a +a new file upon user intervention. The starting address +to be read and the range for each data point in provided +in /sys/kernel/release_region. + +The tools to examine the dump will be same as the ones +used for kdump. + +General notes: +-------------- +Security: please note that there are potential security issues +with any sort of dump mechanism. In particular, plaintext +(unencrypted) data, and possibly passwords, may be present in +the dump data. Userspace tools must take adequate precautions to +preserve security. + +Open issues/ToDo: +------------ + o The various code paths that tell the hypervisor that a crash + occurred, vs. it simply being a normal reboot, should be + reviewed, and possibly clarified/fixed. + + o Instead of using /sys/kernel, should there be a /sys/dump + instead? There is a dump_subsys being created by the s390 code, + perhaps the pseries code should use a similar layout as well. + + o Is reserving a 256MB region really required? The goal of + reserving a 256MB scratch area is to make sure that no + important crash data is clobbered when the hypervisor + save low mem to the scratch area. But, if one could assure + that nothing important is located in some 256MB area, then + it would not need to be reserved. Something that can be + improved in subsequent versions. + + o Still working the kdump team to integrate this with kdump, + some work remains but this would not affect the current + patches. + + o Still need to write a shell script, to copy the dump away. + Currently I am parsing it manually. diff --git a/Documentation/prctl/disable-tsc-ctxt-sw-stress-test.c b/Documentation/prctl/disable-tsc-ctxt-sw-stress-test.c new file mode 100644 index 000000000000..f8e8e95e81fd --- /dev/null +++ b/Documentation/prctl/disable-tsc-ctxt-sw-stress-test.c @@ -0,0 +1,96 @@ +/* + * Tests for prctl(PR_GET_TSC, ...) / prctl(PR_SET_TSC, ...) + * + * Tests if the control register is updated correctly + * at context switches + * + * Warning: this test will cause a very high load for a few seconds + * + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <signal.h> +#include <inttypes.h> +#include <wait.h> + + +#include <sys/prctl.h> +#include <linux/prctl.h> + +/* Get/set the process' ability to use the timestamp counter instruction */ +#ifndef PR_GET_TSC +#define PR_GET_TSC 25 +#define PR_SET_TSC 26 +# define PR_TSC_ENABLE 1 /* allow the use of the timestamp counter */ +# define PR_TSC_SIGSEGV 2 /* throw a SIGSEGV instead of reading the TSC */ +#endif + +uint64_t rdtsc() { +uint32_t lo, hi; +/* We cannot use "=A", since this would use %rax on x86_64 */ +__asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi)); +return (uint64_t)hi << 32 | lo; +} + +void sigsegv_expect(int sig) +{ + /* */ +} + +void segvtask(void) +{ + if (prctl(PR_SET_TSC, PR_TSC_SIGSEGV) < 0) + { + perror("prctl"); + exit(0); + } + signal(SIGSEGV, sigsegv_expect); + alarm(10); + rdtsc(); + fprintf(stderr, "FATAL ERROR, rdtsc() succeeded while disabled\n"); + exit(0); +} + + +void sigsegv_fail(int sig) +{ + fprintf(stderr, "FATAL ERROR, rdtsc() failed while enabled\n"); + exit(0); +} + +void rdtsctask(void) +{ + if (prctl(PR_SET_TSC, PR_TSC_ENABLE) < 0) + { + perror("prctl"); + exit(0); + } + signal(SIGSEGV, sigsegv_fail); + alarm(10); + for(;;) rdtsc(); +} + + +int main(int argc, char **argv) +{ + int n_tasks = 100, i; + + fprintf(stderr, "[No further output means we're allright]\n"); + + for (i=0; i<n_tasks; i++) + if (fork() == 0) + { + if (i & 1) + segvtask(); + else + rdtsctask(); + } + + for (i=0; i<n_tasks; i++) + wait(NULL); + + exit(0); +} + diff --git a/Documentation/prctl/disable-tsc-on-off-stress-test.c b/Documentation/prctl/disable-tsc-on-off-stress-test.c new file mode 100644 index 000000000000..1fcd91445375 --- /dev/null +++ b/Documentation/prctl/disable-tsc-on-off-stress-test.c @@ -0,0 +1,95 @@ +/* + * Tests for prctl(PR_GET_TSC, ...) / prctl(PR_SET_TSC, ...) + * + * Tests if the control register is updated correctly + * when set with prctl() + * + * Warning: this test will cause a very high load for a few seconds + * + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <signal.h> +#include <inttypes.h> +#include <wait.h> + + +#include <sys/prctl.h> +#include <linux/prctl.h> + +/* Get/set the process' ability to use the timestamp counter instruction */ +#ifndef PR_GET_TSC +#define PR_GET_TSC 25 +#define PR_SET_TSC 26 +# define PR_TSC_ENABLE 1 /* allow the use of the timestamp counter */ +# define PR_TSC_SIGSEGV 2 /* throw a SIGSEGV instead of reading the TSC */ +#endif + +/* snippet from wikipedia :-) */ + +uint64_t rdtsc() { +uint32_t lo, hi; +/* We cannot use "=A", since this would use %rax on x86_64 */ +__asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi)); +return (uint64_t)hi << 32 | lo; +} + +int should_segv = 0; + +void sigsegv_cb(int sig) +{ + if (!should_segv) + { + fprintf(stderr, "FATAL ERROR, rdtsc() failed while enabled\n"); + exit(0); + } + if (prctl(PR_SET_TSC, PR_TSC_ENABLE) < 0) + { + perror("prctl"); + exit(0); + } + should_segv = 0; + + rdtsc(); +} + +void task(void) +{ + signal(SIGSEGV, sigsegv_cb); + alarm(10); + for(;;) + { + rdtsc(); + if (should_segv) + { + fprintf(stderr, "FATAL ERROR, rdtsc() succeeded while disabled\n"); + exit(0); + } + if (prctl(PR_SET_TSC, PR_TSC_SIGSEGV) < 0) + { + perror("prctl"); + exit(0); + } + should_segv = 1; + } +} + + +int main(int argc, char **argv) +{ + int n_tasks = 100, i; + + fprintf(stderr, "[No further output means we're allright]\n"); + + for (i=0; i<n_tasks; i++) + if (fork() == 0) + task(); + + for (i=0; i<n_tasks; i++) + wait(NULL); + + exit(0); +} + diff --git a/Documentation/prctl/disable-tsc-test.c b/Documentation/prctl/disable-tsc-test.c new file mode 100644 index 000000000000..843c81eac235 --- /dev/null +++ b/Documentation/prctl/disable-tsc-test.c @@ -0,0 +1,94 @@ +/* + * Tests for prctl(PR_GET_TSC, ...) / prctl(PR_SET_TSC, ...) + * + * Basic test to test behaviour of PR_GET_TSC and PR_SET_TSC + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <signal.h> +#include <inttypes.h> + + +#include <sys/prctl.h> +#include <linux/prctl.h> + +/* Get/set the process' ability to use the timestamp counter instruction */ +#ifndef PR_GET_TSC +#define PR_GET_TSC 25 +#define PR_SET_TSC 26 +# define PR_TSC_ENABLE 1 /* allow the use of the timestamp counter */ +# define PR_TSC_SIGSEGV 2 /* throw a SIGSEGV instead of reading the TSC */ +#endif + +const char *tsc_names[] = +{ + [0] = "[not set]", + [PR_TSC_ENABLE] = "PR_TSC_ENABLE", + [PR_TSC_SIGSEGV] = "PR_TSC_SIGSEGV", +}; + +uint64_t rdtsc() { +uint32_t lo, hi; +/* We cannot use "=A", since this would use %rax on x86_64 */ +__asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi)); +return (uint64_t)hi << 32 | lo; +} + +void sigsegv_cb(int sig) +{ + int tsc_val = 0; + + printf("[ SIG_SEGV ]\n"); + printf("prctl(PR_GET_TSC, &tsc_val); "); + fflush(stdout); + + if ( prctl(PR_GET_TSC, &tsc_val) == -1) + perror("prctl"); + + printf("tsc_val == %s\n", tsc_names[tsc_val]); + printf("prctl(PR_SET_TSC, PR_TSC_ENABLE)\n"); + fflush(stdout); + if ( prctl(PR_SET_TSC, PR_TSC_ENABLE) == -1) + perror("prctl"); + + printf("rdtsc() == "); +} + +int main(int argc, char **argv) +{ + int tsc_val = 0; + + signal(SIGSEGV, sigsegv_cb); + + printf("rdtsc() == %llu\n", (unsigned long long)rdtsc()); + printf("prctl(PR_GET_TSC, &tsc_val); "); + fflush(stdout); + + if ( prctl(PR_GET_TSC, &tsc_val) == -1) + perror("prctl"); + + printf("tsc_val == %s\n", tsc_names[tsc_val]); + printf("rdtsc() == %llu\n", (unsigned long long)rdtsc()); + printf("prctl(PR_SET_TSC, PR_TSC_ENABLE)\n"); + fflush(stdout); + + if ( prctl(PR_SET_TSC, PR_TSC_ENABLE) == -1) + perror("prctl"); + + printf("rdtsc() == %llu\n", (unsigned long long)rdtsc()); + printf("prctl(PR_SET_TSC, PR_TSC_SIGSEGV)\n"); + fflush(stdout); + + if ( prctl(PR_SET_TSC, PR_TSC_SIGSEGV) == -1) + perror("prctl"); + + printf("rdtsc() == "); + fflush(stdout); + printf("%llu\n", (unsigned long long)rdtsc()); + fflush(stdout); + + exit(EXIT_SUCCESS); +} + diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt index 1c6332f4543c..14f901f639ee 100644 --- a/Documentation/scheduler/sched-rt-group.txt +++ b/Documentation/scheduler/sched-rt-group.txt @@ -1,59 +1,177 @@ + Real-Time group scheduling + -------------------------- +CONTENTS +======== -Real-Time group scheduling. +1. Overview + 1.1 The problem + 1.2 The solution +2. The interface + 2.1 System-wide settings + 2.2 Default behaviour + 2.3 Basis for grouping tasks +3. Future plans -The problem space: -In order to schedule multiple groups of realtime tasks each group must -be assigned a fixed portion of the CPU time available. Without a minimum -guarantee a realtime group can obviously fall short. A fuzzy upper limit -is of no use since it cannot be relied upon. Which leaves us with just -the single fixed portion. +1. Overview +=========== -CPU time is divided by means of specifying how much time can be spent -running in a given period. Say a frame fixed realtime renderer must -deliver 25 frames a second, which yields a period of 0.04s. Now say -it will also have to play some music and respond to input, leaving it -with around 80% for the graphics. We can then give this group a runtime -of 0.8 * 0.04s = 0.032s. -This way the graphics group will have a 0.04s period with a 0.032s runtime -limit. +1.1 The problem +--------------- -Now if the audio thread needs to refill the DMA buffer every 0.005s, but -needs only about 3% CPU time to do so, it can do with a 0.03 * 0.005s -= 0.00015s. +Realtime scheduling is all about determinism, a group has to be able to rely on +the amount of bandwidth (eg. CPU time) being constant. In order to schedule +multiple groups of realtime tasks, each group must be assigned a fixed portion +of the CPU time available. Without a minimum guarantee a realtime group can +obviously fall short. A fuzzy upper limit is of no use since it cannot be +relied upon. Which leaves us with just the single fixed portion. +1.2 The solution +---------------- -The Interface: +CPU time is divided by means of specifying how much time can be spent running +in a given period. We allocate this "run time" for each realtime group which +the other realtime groups will not be permitted to use. -system wide: +Any time not allocated to a realtime group will be used to run normal priority +tasks (SCHED_OTHER). Any allocated run time not used will also be picked up by +SCHED_OTHER. -/proc/sys/kernel/sched_rt_period_ms -/proc/sys/kernel/sched_rt_runtime_us +Let's consider an example: a frame fixed realtime renderer must deliver 25 +frames a second, which yields a period of 0.04s per frame. Now say it will also +have to play some music and respond to input, leaving it with around 80% CPU +time dedicated for the graphics. We can then give this group a run time of 0.8 +* 0.04s = 0.032s. -CONFIG_FAIR_USER_SCHED +This way the graphics group will have a 0.04s period with a 0.032s run time +limit. Now if the audio thread needs to refill the DMA buffer every 0.005s, but +needs only about 3% CPU time to do so, it can do with a 0.03 * 0.005s = +0.00015s. So this group can be scheduled with a period of 0.005s and a run time +of 0.00015s. -/sys/kernel/uids/<uid>/cpu_rt_runtime_us +The remaining CPU time will be used for user input and other tass. Because +realtime tasks have explicitly allocated the CPU time they need to perform +their tasks, buffer underruns in the graphocs or audio can be eliminated. -or +NOTE: the above example is not fully implemented as of yet (2.6.25). We still +lack an EDF scheduler to make non-uniform periods usable. -CONFIG_FAIR_CGROUP_SCHED -/cgroup/<cgroup>/cpu.rt_runtime_us +2. The Interface +================ -[ time is specified in us because the interface is s32; this gives an - operating range of ~35m to 1us ] -The period takes values in [ 1, INT_MAX ], runtime in [ -1, INT_MAX - 1 ]. +2.1 System wide settings +------------------------ -A runtime of -1 specifies runtime == period, ie. no limit. +The system wide settings are configured under the /proc virtual file system: -New groups get the period from /proc/sys/kernel/sched_rt_period_us and -a runtime of 0. +/proc/sys/kernel/sched_rt_period_us: + The scheduling period that is equivalent to 100% CPU bandwidth -Settings are constrained to: +/proc/sys/kernel/sched_rt_runtime_us: + A global limit on how much time realtime scheduling may use. Even without + CONFIG_RT_GROUP_SCHED enabled, this will limit time reserved to realtime + processes. With CONFIG_RT_GROUP_SCHED it signifies the total bandwidth + available to all realtime groups. + + * Time is specified in us because the interface is s32. This gives an + operating range from 1us to about 35 minutes. + * sched_rt_period_us takes values from 1 to INT_MAX. + * sched_rt_runtime_us takes values from -1 to (INT_MAX - 1). + * A run time of -1 specifies runtime == period, ie. no limit. + + +2.2 Default behaviour +--------------------- + +The default values for sched_rt_period_us (1000000 or 1s) and +sched_rt_runtime_us (950000 or 0.95s). This gives 0.05s to be used by +SCHED_OTHER (non-RT tasks). These defaults were chosen so that a run-away +realtime tasks will not lock up the machine but leave a little time to recover +it. By setting runtime to -1 you'd get the old behaviour back. + +By default all bandwidth is assigned to the root group and new groups get the +period from /proc/sys/kernel/sched_rt_period_us and a run time of 0. If you +want to assign bandwidth to another group, reduce the root group's bandwidth +and assign some or all of the difference to another group. + +Realtime group scheduling means you have to assign a portion of total CPU +bandwidth to the group before it will accept realtime tasks. Therefore you will +not be able to run realtime tasks as any user other than root until you have +done that, even if the user has the rights to run processes with realtime +priority! + + +2.3 Basis for grouping tasks +---------------------------- + +There are two compile-time settings for allocating CPU bandwidth. These are +configured using the "Basis for grouping tasks" multiple choice menu under +General setup > Group CPU Scheduler: + +a. CONFIG_USER_SCHED (aka "Basis for grouping tasks" = "user id") + +This lets you use the virtual files under +"/sys/kernel/uids/<uid>/cpu_rt_runtime_us" to control he CPU time reserved for +each user . + +The other option is: + +.o CONFIG_CGROUP_SCHED (aka "Basis for grouping tasks" = "Control groups") + +This uses the /cgroup virtual file system and "/cgroup/<cgroup>/cpu.rt_runtime_us" +to control the CPU time reserved for each control group instead. + +For more information on working with control groups, you should read +Documentation/cgroups.txt as well. + +Group settings are checked against the following limits in order to keep the configuration +schedulable: \Sum_{i} runtime_{i} / global_period <= global_runtime / global_period -in order to keep the configuration schedulable. +For now, this can be simplified to just the following (but see Future plans): + + \Sum_{i} runtime_{i} <= global_runtime + + +3. Future plans +=============== + +There is work in progress to make the scheduling period for each group +("/sys/kernel/uids/<uid>/cpu_rt_period_us" or +"/cgroup/<cgroup>/cpu.rt_period_us" respectively) configurable as well. + +The constraint on the period is that a subgroup must have a smaller or +equal period to its parent. But realistically its not very useful _yet_ +as its prone to starvation without deadline scheduling. + +Consider two sibling groups A and B; both have 50% bandwidth, but A's +period is twice the length of B's. + +* group A: period=100000us, runtime=10000us + - this runs for 0.01s once every 0.1s + +* group B: period= 50000us, runtime=10000us + - this runs for 0.01s twice every 0.1s (or once every 0.05 sec). + +This means that currently a while (1) loop in A will run for the full period of +B and can starve B's tasks (assuming they are of lower priority) for a whole +period. + +The next project will be SCHED_EDF (Earliest Deadline First scheduling) to bring +full deadline scheduling to the linux kernel. Deadline scheduling the above +groups and treating end of the period as a deadline will ensure that they both +get their allocated time. + +Implementing SCHED_EDF might take a while to complete. Priority Inheritance is +the biggest challenge as the current linux PI infrastructure is geared towards +the limited static priority levels 0-139. With deadline scheduling you need to +do deadline inheritance (since priority is inversely proportional to the +deadline delta (deadline - now). + +This means the whole PI machinery will have to be reworked - and that is one of +the most complex pieces of code we have. |
