aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/net/macb.txt2
-rw-r--r--Documentation/devicetree/bindings/video/exynos_hdmi.txt (renamed from Documentation/devicetree/bindings/drm/exynos/hdmi.txt)0
-rw-r--r--Documentation/devicetree/bindings/video/exynos_hdmiddc.txt (renamed from Documentation/devicetree/bindings/drm/exynos/hdmiddc.txt)0
-rw-r--r--Documentation/devicetree/bindings/video/exynos_hdmiphy.txt (renamed from Documentation/devicetree/bindings/drm/exynos/hdmiphy.txt)0
-rw-r--r--Documentation/devicetree/bindings/video/exynos_mixer.txt (renamed from Documentation/devicetree/bindings/drm/exynos/mixer.txt)0
-rw-r--r--Documentation/devicetree/bindings/video/simple-framebuffer.txt25
-rw-r--r--Documentation/devicetree/usage-model.txt8
-rw-r--r--Documentation/kernel-parameters.txt21
-rw-r--r--Documentation/kernel-per-CPU-kthreads.txt202
-rw-r--r--Documentation/power/devices.txt15
-rw-r--r--Documentation/power/interface.txt4
-rw-r--r--Documentation/power/notifiers.txt6
-rw-r--r--Documentation/power/states.txt30
-rw-r--r--Documentation/powerpc/transactional_memory.txt27
-rw-r--r--Documentation/rapidio/rapidio.txt128
-rw-r--r--Documentation/rapidio/sysfs.txt17
16 files changed, 444 insertions, 41 deletions
diff --git a/Documentation/devicetree/bindings/net/macb.txt b/Documentation/devicetree/bindings/net/macb.txt
index 44afa0e5057d..4ff65047bb9a 100644
--- a/Documentation/devicetree/bindings/net/macb.txt
+++ b/Documentation/devicetree/bindings/net/macb.txt
@@ -4,7 +4,7 @@ Required properties:
4- compatible: Should be "cdns,[<chip>-]{macb|gem}" 4- compatible: Should be "cdns,[<chip>-]{macb|gem}"
5 Use "cdns,at91sam9260-macb" Atmel at91sam9260 and at91sam9263 SoCs. 5 Use "cdns,at91sam9260-macb" Atmel at91sam9260 and at91sam9263 SoCs.
6 Use "cdns,at32ap7000-macb" for other 10/100 usage or use the generic form: "cdns,macb". 6 Use "cdns,at32ap7000-macb" for other 10/100 usage or use the generic form: "cdns,macb".
7 Use "cnds,pc302-gem" for Picochip picoXcell pc302 and later devices based on 7 Use "cdns,pc302-gem" for Picochip picoXcell pc302 and later devices based on
8 the Cadence GEM, or the generic form: "cdns,gem". 8 the Cadence GEM, or the generic form: "cdns,gem".
9- reg: Address and length of the register set for the device 9- reg: Address and length of the register set for the device
10- interrupts: Should contain macb interrupt 10- interrupts: Should contain macb interrupt
diff --git a/Documentation/devicetree/bindings/drm/exynos/hdmi.txt b/Documentation/devicetree/bindings/video/exynos_hdmi.txt
index 589edee37394..589edee37394 100644
--- a/Documentation/devicetree/bindings/drm/exynos/hdmi.txt
+++ b/Documentation/devicetree/bindings/video/exynos_hdmi.txt
diff --git a/Documentation/devicetree/bindings/drm/exynos/hdmiddc.txt b/Documentation/devicetree/bindings/video/exynos_hdmiddc.txt
index fa166d945809..fa166d945809 100644
--- a/Documentation/devicetree/bindings/drm/exynos/hdmiddc.txt
+++ b/Documentation/devicetree/bindings/video/exynos_hdmiddc.txt
diff --git a/Documentation/devicetree/bindings/drm/exynos/hdmiphy.txt b/Documentation/devicetree/bindings/video/exynos_hdmiphy.txt
index 858f4f9b902f..858f4f9b902f 100644
--- a/Documentation/devicetree/bindings/drm/exynos/hdmiphy.txt
+++ b/Documentation/devicetree/bindings/video/exynos_hdmiphy.txt
diff --git a/Documentation/devicetree/bindings/drm/exynos/mixer.txt b/Documentation/devicetree/bindings/video/exynos_mixer.txt
index 9b2ea0343566..9b2ea0343566 100644
--- a/Documentation/devicetree/bindings/drm/exynos/mixer.txt
+++ b/Documentation/devicetree/bindings/video/exynos_mixer.txt
diff --git a/Documentation/devicetree/bindings/video/simple-framebuffer.txt b/Documentation/devicetree/bindings/video/simple-framebuffer.txt
new file mode 100644
index 000000000000..3ea460583111
--- /dev/null
+++ b/Documentation/devicetree/bindings/video/simple-framebuffer.txt
@@ -0,0 +1,25 @@
1Simple Framebuffer
2
3A simple frame-buffer describes a raw memory region that may be rendered to,
4with the assumption that the display hardware has already been set up to scan
5out from that buffer.
6
7Required properties:
8- compatible: "simple-framebuffer"
9- reg: Should contain the location and size of the framebuffer memory.
10- width: The width of the framebuffer in pixels.
11- height: The height of the framebuffer in pixels.
12- stride: The number of bytes in each line of the framebuffer.
13- format: The format of the framebuffer surface. Valid values are:
14 - r5g6b5 (16-bit pixels, d[15:11]=r, d[10:5]=g, d[4:0]=b).
15
16Example:
17
18 framebuffer {
19 compatible = "simple-framebuffer";
20 reg = <0x1d385000 (1600 * 1200 * 2)>;
21 width = <1600>;
22 height = <1200>;
23 stride = <(1600 * 2)>;
24 format = "r5g6b5";
25 };
diff --git a/Documentation/devicetree/usage-model.txt b/Documentation/devicetree/usage-model.txt
index ef9d06c9f8fd..0efedaad5165 100644
--- a/Documentation/devicetree/usage-model.txt
+++ b/Documentation/devicetree/usage-model.txt
@@ -191,9 +191,11 @@ Linux it will look something like this:
191 }; 191 };
192 192
193The bootargs property contains the kernel arguments, and the initrd-* 193The bootargs property contains the kernel arguments, and the initrd-*
194properties define the address and size of an initrd blob. The 194properties define the address and size of an initrd blob. Note that
195chosen node may also optionally contain an arbitrary number of 195initrd-end is the first address after the initrd image, so this doesn't
196additional properties for platform-specific configuration data. 196match the usual semantic of struct resource. The chosen node may also
197optionally contain an arbitrary number of additional properties for
198platform-specific configuration data.
197 199
198During early boot, the architecture setup code calls of_scan_flat_dt() 200During early boot, the architecture setup code calls of_scan_flat_dt()
199several times with different helper callbacks to parse device tree 201several times with different helper callbacks to parse device tree
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index c3bfacb92910..6e3b18a8afc6 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3005,6 +3005,27 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
3005 Force threading of all interrupt handlers except those 3005 Force threading of all interrupt handlers except those
3006 marked explicitly IRQF_NO_THREAD. 3006 marked explicitly IRQF_NO_THREAD.
3007 3007
3008 tmem [KNL,XEN]
3009 Enable the Transcendent memory driver if built-in.
3010
3011 tmem.cleancache=0|1 [KNL, XEN]
3012 Default is on (1). Disable the usage of the cleancache
3013 API to send anonymous pages to the hypervisor.
3014
3015 tmem.frontswap=0|1 [KNL, XEN]
3016 Default is on (1). Disable the usage of the frontswap
3017 API to send swap pages to the hypervisor. If disabled
3018 the selfballooning and selfshrinking are force disabled.
3019
3020 tmem.selfballooning=0|1 [KNL, XEN]
3021 Default is on (1). Disable the driving of swap pages
3022 to the hypervisor.
3023
3024 tmem.selfshrinking=0|1 [KNL, XEN]
3025 Default is on (1). Partial swapoff that immediately
3026 transfers pages from Xen hypervisor back to the
3027 kernel based on different criteria.
3028
3008 topology= [S390] 3029 topology= [S390]
3009 Format: {off | on} 3030 Format: {off | on}
3010 Specify if the kernel should make use of the cpu 3031 Specify if the kernel should make use of the cpu
diff --git a/Documentation/kernel-per-CPU-kthreads.txt b/Documentation/kernel-per-CPU-kthreads.txt
new file mode 100644
index 000000000000..cbf7ae412da4
--- /dev/null
+++ b/Documentation/kernel-per-CPU-kthreads.txt
@@ -0,0 +1,202 @@
1REDUCING OS JITTER DUE TO PER-CPU KTHREADS
2
3This document lists per-CPU kthreads in the Linux kernel and presents
4options to control their OS jitter. Note that non-per-CPU kthreads are
5not listed here. To reduce OS jitter from non-per-CPU kthreads, bind
6them to a "housekeeping" CPU dedicated to such work.
7
8
9REFERENCES
10
11o Documentation/IRQ-affinity.txt: Binding interrupts to sets of CPUs.
12
13o Documentation/cgroups: Using cgroups to bind tasks to sets of CPUs.
14
15o man taskset: Using the taskset command to bind tasks to sets
16 of CPUs.
17
18o man sched_setaffinity: Using the sched_setaffinity() system
19 call to bind tasks to sets of CPUs.
20
21o /sys/devices/system/cpu/cpuN/online: Control CPU N's hotplug state,
22 writing "0" to offline and "1" to online.
23
24o In order to locate kernel-generated OS jitter on CPU N:
25
26 cd /sys/kernel/debug/tracing
27 echo 1 > max_graph_depth # Increase the "1" for more detail
28 echo function_graph > current_tracer
29 # run workload
30 cat per_cpu/cpuN/trace
31
32
33KTHREADS
34
35Name: ehca_comp/%u
36Purpose: Periodically process Infiniband-related work.
37To reduce its OS jitter, do any of the following:
381. Don't use eHCA Infiniband hardware, instead choosing hardware
39 that does not require per-CPU kthreads. This will prevent these
40 kthreads from being created in the first place. (This will
41 work for most people, as this hardware, though important, is
42 relatively old and is produced in relatively low unit volumes.)
432. Do all eHCA-Infiniband-related work on other CPUs, including
44 interrupts.
453. Rework the eHCA driver so that its per-CPU kthreads are
46 provisioned only on selected CPUs.
47
48
49Name: irq/%d-%s
50Purpose: Handle threaded interrupts.
51To reduce its OS jitter, do the following:
521. Use irq affinity to force the irq threads to execute on
53 some other CPU.
54
55Name: kcmtpd_ctr_%d
56Purpose: Handle Bluetooth work.
57To reduce its OS jitter, do one of the following:
581. Don't use Bluetooth, in which case these kthreads won't be
59 created in the first place.
602. Use irq affinity to force Bluetooth-related interrupts to
61 occur on some other CPU and furthermore initiate all
62 Bluetooth activity on some other CPU.
63
64Name: ksoftirqd/%u
65Purpose: Execute softirq handlers when threaded or when under heavy load.
66To reduce its OS jitter, each softirq vector must be handled
67separately as follows:
68TIMER_SOFTIRQ: Do all of the following:
691. To the extent possible, keep the CPU out of the kernel when it
70 is non-idle, for example, by avoiding system calls and by forcing
71 both kernel threads and interrupts to execute elsewhere.
722. Build with CONFIG_HOTPLUG_CPU=y. After boot completes, force
73 the CPU offline, then bring it back online. This forces
74 recurring timers to migrate elsewhere. If you are concerned
75 with multiple CPUs, force them all offline before bringing the
76 first one back online. Once you have onlined the CPUs in question,
77 do not offline any other CPUs, because doing so could force the
78 timer back onto one of the CPUs in question.
79NET_TX_SOFTIRQ and NET_RX_SOFTIRQ: Do all of the following:
801. Force networking interrupts onto other CPUs.
812. Initiate any network I/O on other CPUs.
823. Once your application has started, prevent CPU-hotplug operations
83 from being initiated from tasks that might run on the CPU to
84 be de-jittered. (It is OK to force this CPU offline and then
85 bring it back online before you start your application.)
86BLOCK_SOFTIRQ: Do all of the following:
871. Force block-device interrupts onto some other CPU.
882. Initiate any block I/O on other CPUs.
893. Once your application has started, prevent CPU-hotplug operations
90 from being initiated from tasks that might run on the CPU to
91 be de-jittered. (It is OK to force this CPU offline and then
92 bring it back online before you start your application.)
93BLOCK_IOPOLL_SOFTIRQ: Do all of the following:
941. Force block-device interrupts onto some other CPU.
952. Initiate any block I/O and block-I/O polling on other CPUs.
963. Once your application has started, prevent CPU-hotplug operations
97 from being initiated from tasks that might run on the CPU to
98 be de-jittered. (It is OK to force this CPU offline and then
99 bring it back online before you start your application.)
100TASKLET_SOFTIRQ: Do one or more of the following:
1011. Avoid use of drivers that use tasklets. (Such drivers will contain
102 calls to things like tasklet_schedule().)
1032. Convert all drivers that you must use from tasklets to workqueues.
1043. Force interrupts for drivers using tasklets onto other CPUs,
105 and also do I/O involving these drivers on other CPUs.
106SCHED_SOFTIRQ: Do all of the following:
1071. Avoid sending scheduler IPIs to the CPU to be de-jittered,
108 for example, ensure that at most one runnable kthread is present
109 on that CPU. If a thread that expects to run on the de-jittered
110 CPU awakens, the scheduler will send an IPI that can result in
111 a subsequent SCHED_SOFTIRQ.
1122. Build with CONFIG_RCU_NOCB_CPU=y, CONFIG_RCU_NOCB_CPU_ALL=y,
113 CONFIG_NO_HZ_FULL=y, and, in addition, ensure that the CPU
114 to be de-jittered is marked as an adaptive-ticks CPU using the
115 "nohz_full=" boot parameter. This reduces the number of
116 scheduler-clock interrupts that the de-jittered CPU receives,
117 minimizing its chances of being selected to do the load balancing
118 work that runs in SCHED_SOFTIRQ context.
1193. To the extent possible, keep the CPU out of the kernel when it
120 is non-idle, for example, by avoiding system calls and by
121 forcing both kernel threads and interrupts to execute elsewhere.
122 This further reduces the number of scheduler-clock interrupts
123 received by the de-jittered CPU.
124HRTIMER_SOFTIRQ: Do all of the following:
1251. To the extent possible, keep the CPU out of the kernel when it
126 is non-idle. For example, avoid system calls and force both
127 kernel threads and interrupts to execute elsewhere.
1282. Build with CONFIG_HOTPLUG_CPU=y. Once boot completes, force the
129 CPU offline, then bring it back online. This forces recurring
130 timers to migrate elsewhere. If you are concerned with multiple
131 CPUs, force them all offline before bringing the first one
132 back online. Once you have onlined the CPUs in question, do not
133 offline any other CPUs, because doing so could force the timer
134 back onto one of the CPUs in question.
135RCU_SOFTIRQ: Do at least one of the following:
1361. Offload callbacks and keep the CPU in either dyntick-idle or
137 adaptive-ticks state by doing all of the following:
138 a. Build with CONFIG_RCU_NOCB_CPU=y, CONFIG_RCU_NOCB_CPU_ALL=y,
139 CONFIG_NO_HZ_FULL=y, and, in addition ensure that the CPU
140 to be de-jittered is marked as an adaptive-ticks CPU using
141 the "nohz_full=" boot parameter. Bind the rcuo kthreads
142 to housekeeping CPUs, which can tolerate OS jitter.
143 b. To the extent possible, keep the CPU out of the kernel
144 when it is non-idle, for example, by avoiding system
145 calls and by forcing both kernel threads and interrupts
146 to execute elsewhere.
1472. Enable RCU to do its processing remotely via dyntick-idle by
148 doing all of the following:
149 a. Build with CONFIG_NO_HZ=y and CONFIG_RCU_FAST_NO_HZ=y.
150 b. Ensure that the CPU goes idle frequently, allowing other
151 CPUs to detect that it has passed through an RCU quiescent
152 state. If the kernel is built with CONFIG_NO_HZ_FULL=y,
153 userspace execution also allows other CPUs to detect that
154 the CPU in question has passed through a quiescent state.
155 c. To the extent possible, keep the CPU out of the kernel
156 when it is non-idle, for example, by avoiding system
157 calls and by forcing both kernel threads and interrupts
158 to execute elsewhere.
159
160Name: rcuc/%u
161Purpose: Execute RCU callbacks in CONFIG_RCU_BOOST=y kernels.
162To reduce its OS jitter, do at least one of the following:
1631. Build the kernel with CONFIG_PREEMPT=n. This prevents these
164 kthreads from being created in the first place, and also obviates
165 the need for RCU priority boosting. This approach is feasible
166 for workloads that do not require high degrees of responsiveness.
1672. Build the kernel with CONFIG_RCU_BOOST=n. This prevents these
168 kthreads from being created in the first place. This approach
169 is feasible only if your workload never requires RCU priority
170 boosting, for example, if you ensure frequent idle time on all
171 CPUs that might execute within the kernel.
1723. Build with CONFIG_RCU_NOCB_CPU=y and CONFIG_RCU_NOCB_CPU_ALL=y,
173 which offloads all RCU callbacks to kthreads that can be moved
174 off of CPUs susceptible to OS jitter. This approach prevents the
175 rcuc/%u kthreads from having any work to do, so that they are
176 never awakened.
1774. Ensure that the CPU never enters the kernel, and, in particular,
178 avoid initiating any CPU hotplug operations on this CPU. This is
179 another way of preventing any callbacks from being queued on the
180 CPU, again preventing the rcuc/%u kthreads from having any work
181 to do.
182
183Name: rcuob/%d, rcuop/%d, and rcuos/%d
184Purpose: Offload RCU callbacks from the corresponding CPU.
185To reduce its OS jitter, do at least one of the following:
1861. Use affinity, cgroups, or other mechanism to force these kthreads
187 to execute on some other CPU.
1882. Build with CONFIG_RCU_NOCB_CPUS=n, which will prevent these
189 kthreads from being created in the first place. However, please
190 note that this will not eliminate OS jitter, but will instead
191 shift it to RCU_SOFTIRQ.
192
193Name: watchdog/%u
194Purpose: Detect software lockups on each CPU.
195To reduce its OS jitter, do at least one of the following:
1961. Build with CONFIG_LOCKUP_DETECTOR=n, which will prevent these
197 kthreads from being created in the first place.
1982. Echo a zero to /proc/sys/kernel/watchdog to disable the
199 watchdog timer.
2003. Echo a large number of /proc/sys/kernel/watchdog_thresh in
201 order to reduce the frequency of OS jitter due to the watchdog
202 timer down to a level that is acceptable for your workload.
diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt
index 504dfe4d52eb..a66c9821b5ce 100644
--- a/Documentation/power/devices.txt
+++ b/Documentation/power/devices.txt
@@ -268,7 +268,7 @@ situations.
268System Power Management Phases 268System Power Management Phases
269------------------------------ 269------------------------------
270Suspending or resuming the system is done in several phases. Different phases 270Suspending or resuming the system is done in several phases. Different phases
271are used for standby or memory sleep states ("suspend-to-RAM") and the 271are used for freeze, standby, and memory sleep states ("suspend-to-RAM") and the
272hibernation state ("suspend-to-disk"). Each phase involves executing callbacks 272hibernation state ("suspend-to-disk"). Each phase involves executing callbacks
273for every device before the next phase begins. Not all busses or classes 273for every device before the next phase begins. Not all busses or classes
274support all these callbacks and not all drivers use all the callbacks. The 274support all these callbacks and not all drivers use all the callbacks. The
@@ -309,7 +309,8 @@ execute the corresponding method from dev->driver->pm instead if there is one.
309 309
310Entering System Suspend 310Entering System Suspend
311----------------------- 311-----------------------
312When the system goes into the standby or memory sleep state, the phases are: 312When the system goes into the freeze, standby or memory sleep state,
313the phases are:
313 314
314 prepare, suspend, suspend_late, suspend_noirq. 315 prepare, suspend, suspend_late, suspend_noirq.
315 316
@@ -368,7 +369,7 @@ the devices that were suspended.
368 369
369Leaving System Suspend 370Leaving System Suspend
370---------------------- 371----------------------
371When resuming from standby or memory sleep, the phases are: 372When resuming from freeze, standby or memory sleep, the phases are:
372 373
373 resume_noirq, resume_early, resume, complete. 374 resume_noirq, resume_early, resume, complete.
374 375
@@ -433,8 +434,8 @@ the system log.
433 434
434Entering Hibernation 435Entering Hibernation
435-------------------- 436--------------------
436Hibernating the system is more complicated than putting it into the standby or 437Hibernating the system is more complicated than putting it into the other
437memory sleep state, because it involves creating and saving a system image. 438sleep states, because it involves creating and saving a system image.
438Therefore there are more phases for hibernation, with a different set of 439Therefore there are more phases for hibernation, with a different set of
439callbacks. These phases always run after tasks have been frozen and memory has 440callbacks. These phases always run after tasks have been frozen and memory has
440been freed. 441been freed.
@@ -485,8 +486,8 @@ image forms an atomic snapshot of the system state.
485 486
486At this point the system image is saved, and the devices then need to be 487At this point the system image is saved, and the devices then need to be
487prepared for the upcoming system shutdown. This is much like suspending them 488prepared for the upcoming system shutdown. This is much like suspending them
488before putting the system into the standby or memory sleep state, and the phases 489before putting the system into the freeze, standby or memory sleep state,
489are similar. 490and the phases are similar.
490 491
491 9. The prepare phase is discussed above. 492 9. The prepare phase is discussed above.
492 493
diff --git a/Documentation/power/interface.txt b/Documentation/power/interface.txt
index c537834af005..f1f0f59a7c47 100644
--- a/Documentation/power/interface.txt
+++ b/Documentation/power/interface.txt
@@ -7,8 +7,8 @@ running. The interface exists in /sys/power/ directory (assuming sysfs
7is mounted at /sys). 7is mounted at /sys).
8 8
9/sys/power/state controls system power state. Reading from this file 9/sys/power/state controls system power state. Reading from this file
10returns what states are supported, which is hard-coded to 'standby' 10returns what states are supported, which is hard-coded to 'freeze',
11(Power-On Suspend), 'mem' (Suspend-to-RAM), and 'disk' 11'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and 'disk'
12(Suspend-to-Disk). 12(Suspend-to-Disk).
13 13
14Writing to this file one of those strings causes the system to 14Writing to this file one of those strings causes the system to
diff --git a/Documentation/power/notifiers.txt b/Documentation/power/notifiers.txt
index c2a4a346c0d9..a81fa254303d 100644
--- a/Documentation/power/notifiers.txt
+++ b/Documentation/power/notifiers.txt
@@ -15,8 +15,10 @@ A suspend/hibernation notifier may be used for this purpose.
15The subsystems or drivers having such needs can register suspend notifiers that 15The subsystems or drivers having such needs can register suspend notifiers that
16will be called upon the following events by the PM core: 16will be called upon the following events by the PM core:
17 17
18PM_HIBERNATION_PREPARE The system is going to hibernate or suspend, tasks will 18PM_HIBERNATION_PREPARE The system is going to hibernate, tasks will be frozen
19 be frozen immediately. 19 immediately. This is different from PM_SUSPEND_PREPARE
20 below because here we do additional work between notifiers
21 and drivers freezing.
20 22
21PM_POST_HIBERNATION The system memory state has been restored from a 23PM_POST_HIBERNATION The system memory state has been restored from a
22 hibernation image or an error occurred during 24 hibernation image or an error occurred during
diff --git a/Documentation/power/states.txt b/Documentation/power/states.txt
index 4416b28630df..442d43df9b25 100644
--- a/Documentation/power/states.txt
+++ b/Documentation/power/states.txt
@@ -2,12 +2,26 @@
2System Power Management States 2System Power Management States
3 3
4 4
5The kernel supports three power management states generically, though 5The kernel supports four power management states generically, though
6each is dependent on platform support code to implement the low-level 6one is generic and the other three are dependent on platform support
7details for each state. This file describes each state, what they are 7code to implement the low-level details for each state.
8This file describes each state, what they are
8commonly called, what ACPI state they map to, and what string to write 9commonly called, what ACPI state they map to, and what string to write
9to /sys/power/state to enter that state 10to /sys/power/state to enter that state
10 11
12state: Freeze / Low-Power Idle
13ACPI state: S0
14String: "freeze"
15
16This state is a generic, pure software, light-weight, low-power state.
17It allows more energy to be saved relative to idle by freezing user
18space and putting all I/O devices into low-power states (possibly
19lower-power than available at run time), such that the processors can
20spend more time in their idle states.
21This state can be used for platforms without Standby/Suspend-to-RAM
22support, or it can be used in addition to Suspend-to-RAM (memory sleep)
23to provide reduced resume latency.
24
11 25
12State: Standby / Power-On Suspend 26State: Standby / Power-On Suspend
13ACPI State: S1 27ACPI State: S1
@@ -22,9 +36,6 @@ We try to put devices in a low-power state equivalent to D1, which
22also offers low power savings, but low resume latency. Not all devices 36also offers low power savings, but low resume latency. Not all devices
23support D1, and those that don't are left on. 37support D1, and those that don't are left on.
24 38
25A transition from Standby to the On state should take about 1-2
26seconds.
27
28 39
29State: Suspend-to-RAM 40State: Suspend-to-RAM
30ACPI State: S3 41ACPI State: S3
@@ -42,9 +53,6 @@ transition back to the On state.
42For at least ACPI, STR requires some minimal boot-strapping code to 53For at least ACPI, STR requires some minimal boot-strapping code to
43resume the system from STR. This may be true on other platforms. 54resume the system from STR. This may be true on other platforms.
44 55
45A transition from Suspend-to-RAM to the On state should take about
463-5 seconds.
47
48 56
49State: Suspend-to-disk 57State: Suspend-to-disk
50ACPI State: S4 58ACPI State: S4
@@ -74,7 +82,3 @@ low-power state (like ACPI S4), or it may simply power down. Powering
74down offers greater savings, and allows this mechanism to work on any 82down offers greater savings, and allows this mechanism to work on any
75system. However, entering a real low-power state allows the user to 83system. However, entering a real low-power state allows the user to
76trigger wake up events (e.g. pressing a key or opening a laptop lid). 84trigger wake up events (e.g. pressing a key or opening a laptop lid).
77
78A transition from Suspend-to-Disk to the On state should take about 30
79seconds, though it's typically a bit more with the current
80implementation.
diff --git a/Documentation/powerpc/transactional_memory.txt b/Documentation/powerpc/transactional_memory.txt
index c907be41d60f..dc23e58ae264 100644
--- a/Documentation/powerpc/transactional_memory.txt
+++ b/Documentation/powerpc/transactional_memory.txt
@@ -147,6 +147,25 @@ Example signal handler:
147 fix_the_problem(ucp->dar); 147 fix_the_problem(ucp->dar);
148 } 148 }
149 149
150When in an active transaction that takes a signal, we need to be careful with
151the stack. It's possible that the stack has moved back up after the tbegin.
152The obvious case here is when the tbegin is called inside a function that
153returns before a tend. In this case, the stack is part of the checkpointed
154transactional memory state. If we write over this non transactionally or in
155suspend, we are in trouble because if we get a tm abort, the program counter and
156stack pointer will be back at the tbegin but our in memory stack won't be valid
157anymore.
158
159To avoid this, when taking a signal in an active transaction, we need to use
160the stack pointer from the checkpointed state, rather than the speculated
161state. This ensures that the signal context (written tm suspended) will be
162written below the stack required for the rollback. The transaction is aborted
163becuase of the treclaim, so any memory written between the tbegin and the
164signal will be rolled back anyway.
165
166For signals taken in non-TM or suspended mode, we use the
167normal/non-checkpointed stack pointer.
168
150 169
151Failure cause codes used by kernel 170Failure cause codes used by kernel
152================================== 171==================================
@@ -155,14 +174,18 @@ These are defined in <asm/reg.h>, and distinguish different reasons why the
155kernel aborted a transaction: 174kernel aborted a transaction:
156 175
157 TM_CAUSE_RESCHED Thread was rescheduled. 176 TM_CAUSE_RESCHED Thread was rescheduled.
177 TM_CAUSE_TLBI Software TLB invalide.
158 TM_CAUSE_FAC_UNAV FP/VEC/VSX unavailable trap. 178 TM_CAUSE_FAC_UNAV FP/VEC/VSX unavailable trap.
159 TM_CAUSE_SYSCALL Currently unused; future syscalls that must abort 179 TM_CAUSE_SYSCALL Currently unused; future syscalls that must abort
160 transactions for consistency will use this. 180 transactions for consistency will use this.
161 TM_CAUSE_SIGNAL Signal delivered. 181 TM_CAUSE_SIGNAL Signal delivered.
162 TM_CAUSE_MISC Currently unused. 182 TM_CAUSE_MISC Currently unused.
183 TM_CAUSE_ALIGNMENT Alignment fault.
184 TM_CAUSE_EMULATE Emulation that touched memory.
163 185
164These can be checked by the user program's abort handler as TEXASR[0:7]. 186These can be checked by the user program's abort handler as TEXASR[0:7]. If
165 187bit 7 is set, it indicates that the error is consider persistent. For example
188a TM_CAUSE_ALIGNMENT will be persistent while a TM_CAUSE_RESCHED will not.q
166 189
167GDB 190GDB
168=== 191===
diff --git a/Documentation/rapidio/rapidio.txt b/Documentation/rapidio/rapidio.txt
index c75694b35d08..a9c16c979da2 100644
--- a/Documentation/rapidio/rapidio.txt
+++ b/Documentation/rapidio/rapidio.txt
@@ -79,20 +79,63 @@ master port that is used to communicate with devices within the network.
79In order to initialize the RapidIO subsystem, a platform must initialize and 79In order to initialize the RapidIO subsystem, a platform must initialize and
80register at least one master port within the RapidIO network. To register mport 80register at least one master port within the RapidIO network. To register mport
81within the subsystem controller driver initialization code calls function 81within the subsystem controller driver initialization code calls function
82rio_register_mport() for each available master port. After all active master 82rio_register_mport() for each available master port.
83ports are registered with a RapidIO subsystem, the rio_init_mports() routine
84is called to perform enumeration and discovery.
85 83
86In the current PowerPC-based implementation a subsys_initcall() is specified to 84RapidIO subsystem uses subsys_initcall() or device_initcall() to perform
87perform controller initialization and mport registration. At the end it directly 85controller initialization (depending on controller device type).
88calls rio_init_mports() to execute RapidIO enumeration and discovery. 86
87After all active master ports are registered with a RapidIO subsystem,
88an enumeration and/or discovery routine may be called automatically or
89by user-space command.
89 90
904. Enumeration and Discovery 914. Enumeration and Discovery
91---------------------------- 92----------------------------
92 93
93When rio_init_mports() is called it scans a list of registered master ports and 944.1 Overview
94calls an enumeration or discovery routine depending on the configured role of a 95------------
95master port: host or agent. 96
97RapidIO subsystem configuration options allow users to specify enumeration and
98discovery methods as statically linked components or loadable modules.
99An enumeration/discovery method implementation and available input parameters
100define how any given method can be attached to available RapidIO mports:
101simply to all available mports OR individually to the specified mport device.
102
103Depending on selected enumeration/discovery build configuration, there are
104several methods to initiate an enumeration and/or discovery process:
105
106 (a) Statically linked enumeration and discovery process can be started
107 automatically during kernel initialization time using corresponding module
108 parameters. This was the original method used since introduction of RapidIO
109 subsystem. Now this method relies on enumerator module parameter which is
110 'rio-scan.scan' for existing basic enumeration/discovery method.
111 When automatic start of enumeration/discovery is used a user has to ensure
112 that all discovering endpoints are started before the enumerating endpoint
113 and are waiting for enumeration to be completed.
114 Configuration option CONFIG_RAPIDIO_DISC_TIMEOUT defines time that discovering
115 endpoint waits for enumeration to be completed. If the specified timeout
116 expires the discovery process is terminated without obtaining RapidIO network
117 information. NOTE: a timed out discovery process may be restarted later using
118 a user-space command as it is described later if the given endpoint was
119 enumerated successfully.
120
121 (b) Statically linked enumeration and discovery process can be started by
122 a command from user space. This initiation method provides more flexibility
123 for a system startup compared to the option (a) above. After all participating
124 endpoints have been successfully booted, an enumeration process shall be
125 started first by issuing a user-space command, after an enumeration is
126 completed a discovery process can be started on all remaining endpoints.
127
128 (c) Modular enumeration and discovery process can be started by a command from
129 user space. After an enumeration/discovery module is loaded, a network scan
130 process can be started by issuing a user-space command.
131 Similar to the option (b) above, an enumerator has to be started first.
132
133 (d) Modular enumeration and discovery process can be started by a module
134 initialization routine. In this case an enumerating module shall be loaded
135 first.
136
137When a network scan process is started it calls an enumeration or discovery
138routine depending on the configured role of a master port: host or agent.
96 139
97Enumeration is performed by a master port if it is configured as a host port by 140Enumeration is performed by a master port if it is configured as a host port by
98assigning a host device ID greater than or equal to zero. A host device ID is 141assigning a host device ID greater than or equal to zero. A host device ID is
@@ -104,8 +147,58 @@ for it.
104The enumeration and discovery routines use RapidIO maintenance transactions 147The enumeration and discovery routines use RapidIO maintenance transactions
105to access the configuration space of devices. 148to access the configuration space of devices.
106 149
107The enumeration process is implemented according to the enumeration algorithm 1504.2 Automatic Start of Enumeration and Discovery
108outlined in the RapidIO Interconnect Specification: Annex I [1]. 151------------------------------------------------
152
153Automatic enumeration/discovery start method is applicable only to built-in
154enumeration/discovery RapidIO configuration selection. To enable automatic
155enumeration/discovery start by existing basic enumerator method set use boot
156command line parameter "rio-scan.scan=1".
157
158This configuration requires synchronized start of all RapidIO endpoints that
159form a network which will be enumerated/discovered. Discovering endpoints have
160to be started before an enumeration starts to ensure that all RapidIO
161controllers have been initialized and are ready to be discovered. Configuration
162parameter CONFIG_RAPIDIO_DISC_TIMEOUT defines time (in seconds) which
163a discovering endpoint will wait for enumeration to be completed.
164
165When automatic enumeration/discovery start is selected, basic method's
166initialization routine calls rio_init_mports() to perform enumeration or
167discovery for all known mport devices.
168
169Depending on RapidIO network size and configuration this automatic
170enumeration/discovery start method may be difficult to use due to the
171requirement for synchronized start of all endpoints.
172
1734.3 User-space Start of Enumeration and Discovery
174-------------------------------------------------
175
176User-space start of enumeration and discovery can be used with built-in and
177modular build configurations. For user-space controlled start RapidIO subsystem
178creates the sysfs write-only attribute file '/sys/bus/rapidio/scan'. To initiate
179an enumeration or discovery process on specific mport device, a user needs to
180write mport_ID (not RapidIO destination ID) into that file. The mport_ID is a
181sequential number (0 ... RIO_MAX_MPORTS) assigned during mport device
182registration. For example for machine with single RapidIO controller, mport_ID
183for that controller always will be 0.
184
185To initiate RapidIO enumeration/discovery on all available mports a user may
186write '-1' (or RIO_MPORT_ANY) into the scan attribute file.
187
1884.4 Basic Enumeration Method
189----------------------------
190
191This is an original enumeration/discovery method which is available since
192first release of RapidIO subsystem code. The enumeration process is
193implemented according to the enumeration algorithm outlined in the RapidIO
194Interconnect Specification: Annex I [1].
195
196This method can be configured as statically linked or loadable module.
197The method's single parameter "scan" allows to trigger the enumeration/discovery
198process from module initialization routine.
199
200This enumeration/discovery method can be started only once and does not support
201unloading if it is built as a module.
109 202
110The enumeration process traverses the network using a recursive depth-first 203The enumeration process traverses the network using a recursive depth-first
111algorithm. When a new device is found, the enumerator takes ownership of that 204algorithm. When a new device is found, the enumerator takes ownership of that
@@ -160,6 +253,19 @@ time period. If this wait time period expires before enumeration is completed,
160an agent skips RapidIO discovery and continues with remaining kernel 253an agent skips RapidIO discovery and continues with remaining kernel
161initialization. 254initialization.
162 255
2564.5 Adding New Enumeration/Discovery Method
257-------------------------------------------
258
259RapidIO subsystem code organization allows addition of new enumeration/discovery
260methods as new configuration options without significant impact to to the core
261RapidIO code.
262
263A new enumeration/discovery method has to be attached to one or more mport
264devices before an enumeration/discovery process can be started. Normally,
265method's module initialization routine calls rio_register_scan() to attach
266an enumerator to a specified mport device (or devices). The basic enumerator
267implementation demonstrates this process.
268
1635. References 2695. References
164------------- 270-------------
165 271
diff --git a/Documentation/rapidio/sysfs.txt b/Documentation/rapidio/sysfs.txt
index 97f71ce575d6..19878179da4c 100644
--- a/Documentation/rapidio/sysfs.txt
+++ b/Documentation/rapidio/sysfs.txt
@@ -88,3 +88,20 @@ that exports additional attributes.
88 88
89IDT_GEN2: 89IDT_GEN2:
90 errlog - reads contents of device error log until it is empty. 90 errlog - reads contents of device error log until it is empty.
91
92
935. RapidIO Bus Attributes
94-------------------------
95
96RapidIO bus subdirectory /sys/bus/rapidio implements the following bus-specific
97attribute:
98
99 scan - allows to trigger enumeration discovery process from user space. This
100 is a write-only attribute. To initiate an enumeration or discovery
101 process on specific mport device, a user needs to write mport_ID (not
102 RapidIO destination ID) into this file. The mport_ID is a sequential
103 number (0 ... RIO_MAX_MPORTS) assigned to the mport device.
104 For example, for a machine with a single RapidIO controller, mport_ID
105 for that controller always will be 0.
106 To initiate RapidIO enumeration/discovery on all available mports
107 a user must write '-1' (or RIO_MPORT_ANY) into this attribute file.