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| author | Radim Krčmář <rkrcmar@redhat.com> | 2018-02-01 15:04:17 +0100 |
|---|---|---|
| committer | Radim Krčmář <rkrcmar@redhat.com> | 2018-02-01 15:04:17 +0100 |
| commit | 7bf14c28ee776be567855bd39ed8ff795ea19f55 (patch) | |
| tree | 6113748c673e85fccc2c56c050697789c00c6bc2 /Documentation | |
| parent | 87cedc6be55954c6efd6eca2e694132513f65a2a (diff) | |
| parent | 5fa4ec9cb2e6679e2f828033726f758ea314b9c5 (diff) | |
Merge branch 'x86/hyperv' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Topic branch for stable KVM clockource under Hyper-V.
Thanks to Christoffer Dall for resolving the ARM conflict.
Diffstat (limited to 'Documentation')
94 files changed, 1794 insertions, 1405 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 new file mode 100644 index 000000000000..da9822309f07 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 @@ -0,0 +1,16 @@ +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_spi_clk_freq +KernelVersion: 4.14 +Contact: arnaud.pouliquen@st.com +Description: + For audio purpose only. + Used by audio driver to set/get the spi input frequency. + This is mandatory if DFSDM is slave on SPI bus, to + provide information on the SPI clock frequency during runtime + Notice that the SPI frequency should be a multiple of sample + frequency to ensure the precision. + if DFSDM input is SPI master + Reading SPI clkout frequency, + error on writing + If DFSDM input is SPI Slave: + Reading returns value previously set. + Writing value before starting conversions.
\ No newline at end of file diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index d6d862db3b5d..bfd29bc8d37a 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -375,3 +375,19 @@ Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> Description: information about CPUs heterogeneity. cpu_capacity: capacity of cpu#. + +What: /sys/devices/system/cpu/vulnerabilities + /sys/devices/system/cpu/vulnerabilities/meltdown + /sys/devices/system/cpu/vulnerabilities/spectre_v1 + /sys/devices/system/cpu/vulnerabilities/spectre_v2 +Date: January 2018 +Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> +Description: Information about CPU vulnerabilities + + The files are named after the code names of CPU + vulnerabilities. The output of those files reflects the + state of the CPUs in the system. Possible output values: + + "Not affected" CPU is not affected by the vulnerability + "Vulnerable" CPU is affected and no mitigation in effect + "Mitigation: $M" CPU is affected and mitigation $M is in effect diff --git a/Documentation/IRQ-domain.txt b/Documentation/IRQ-domain.txt index 4a1cd7645d85..507775cce753 100644 --- a/Documentation/IRQ-domain.txt +++ b/Documentation/IRQ-domain.txt @@ -265,37 +265,5 @@ support other architectures, such as ARM, ARM64 etc. === Debugging === -If you switch on CONFIG_IRQ_DOMAIN_DEBUG (which depends on -CONFIG_IRQ_DOMAIN and CONFIG_DEBUG_FS), you will find a new file in -your debugfs mount point, called irq_domain_mapping. This file -contains a live snapshot of all the IRQ domains in the system: - - name mapped linear-max direct-max devtree-node - pl061 8 8 0 /smb/gpio@e0080000 - pl061 8 8 0 /smb/gpio@e1050000 - pMSI 0 0 0 /interrupt-controller@e1101000/v2m@e0080000 - MSI 37 0 0 /interrupt-controller@e1101000/v2m@e0080000 - GICv2m 37 0 0 /interrupt-controller@e1101000/v2m@e0080000 - GICv2 448 448 0 /interrupt-controller@e1101000 - -it also iterates over the interrupts to display their mapping in the -domains, and makes the domain stacking visible: - - -irq hwirq chip name chip data active type domain - 1 0x00019 GICv2 0xffff00000916bfd8 * LINEAR GICv2 - 2 0x0001d GICv2 0xffff00000916bfd8 LINEAR GICv2 - 3 0x0001e GICv2 0xffff00000916bfd8 * LINEAR GICv2 - 4 0x0001b GICv2 0xffff00000916bfd8 * LINEAR GICv2 - 5 0x0001a GICv2 0xffff00000916bfd8 LINEAR GICv2 -[...] - 96 0x81808 MSI 0x (null) RADIX MSI - 96+ 0x00063 GICv2m 0xffff8003ee116980 RADIX GICv2m - 96+ 0x00063 GICv2 0xffff00000916bfd8 LINEAR GICv2 - 97 0x08800 MSI 0x (null) * RADIX MSI - 97+ 0x00064 GICv2m 0xffff8003ee116980 * RADIX GICv2m - 97+ 0x00064 GICv2 0xffff00000916bfd8 * LINEAR GICv2 - -Here, interrupts 1-5 are only using a single domain, while 96 and 97 -are build out of a stack of three domain, each level performing a -particular function. +Most of the internals of the IRQ subsystem are exposed in debugfs by +turning CONFIG_GENERIC_IRQ_DEBUGFS on. diff --git a/Documentation/RCU/Design/Data-Structures/Data-Structures.html b/Documentation/RCU/Design/Data-Structures/Data-Structures.html index 38d6d800761f..6c06e10bd04b 100644 --- a/Documentation/RCU/Design/Data-Structures/Data-Structures.html +++ b/Documentation/RCU/Design/Data-Structures/Data-Structures.html @@ -1097,7 +1097,8 @@ will cause the CPU to disregard the values of its counters on its next exit from idle. Finally, the <tt>rcu_qs_ctr_snap</tt> field is used to detect cases where a given operation has resulted in a quiescent state -for all flavors of RCU, for example, <tt>cond_resched_rcu_qs()</tt>. +for all flavors of RCU, for example, <tt>cond_resched()</tt> +when RCU has indicated a need for quiescent states. <h5>RCU Callback Handling</h5> @@ -1182,8 +1183,8 @@ CPU (and from tracing) unless otherwise stated. Its fields are as follows: <pre> - 1 int dynticks_nesting; - 2 int dynticks_nmi_nesting; + 1 long dynticks_nesting; + 2 long dynticks_nmi_nesting; 3 atomic_t dynticks; 4 bool rcu_need_heavy_qs; 5 unsigned long rcu_qs_ctr; @@ -1191,15 +1192,31 @@ Its fields are as follows: </pre> <p>The <tt>->dynticks_nesting</tt> field counts the -nesting depth of normal interrupts. -In addition, this counter is incremented when exiting dyntick-idle -mode and decremented when entering it. +nesting depth of process execution, so that in normal circumstances +this counter has value zero or one. +NMIs, irqs, and tracers are counted by the <tt>->dynticks_nmi_nesting</tt> +field. +Because NMIs cannot be masked, changes to this variable have to be +undertaken carefully using an algorithm provided by Andy Lutomirski. +The initial transition from idle adds one, and nested transitions +add two, so that a nesting level of five is represented by a +<tt>->dynticks_nmi_nesting</tt> value of nine. This counter can therefore be thought of as counting the number of reasons why this CPU cannot be permitted to enter dyntick-idle -mode, aside from non-maskable interrupts (NMIs). -NMIs are counted by the <tt>->dynticks_nmi_nesting</tt> -field, except that NMIs that interrupt non-dyntick-idle execution -are not counted. +mode, aside from process-level transitions. + +<p>However, it turns out that when running in non-idle kernel context, +the Linux kernel is fully capable of entering interrupt handlers that +never exit and perhaps also vice versa. +Therefore, whenever the <tt>->dynticks_nesting</tt> field is +incremented up from zero, the <tt>->dynticks_nmi_nesting</tt> field +is set to a large positive number, and whenever the +<tt>->dynticks_nesting</tt> field is decremented down to zero, +the the <tt>->dynticks_nmi_nesting</tt> field is set to zero. +Assuming that the number of misnested interrupts is not sufficient +to overflow the counter, this approach corrects the +<tt>->dynticks_nmi_nesting</tt> field every time the corresponding +CPU enters the idle loop from process context. </p><p>The <tt>->dynticks</tt> field counts the corresponding CPU's transitions to and from dyntick-idle mode, so that this counter @@ -1231,14 +1248,16 @@ in response. <tr><th> </th></tr> <tr><th align="left">Quick Quiz:</th></tr> <tr><td> - Why not just count all NMIs? - Wouldn't that be simpler and less error prone? + Why not simply combine the <tt>->dynticks_nesting</tt> + and <tt>->dynticks_nmi_nesting</tt> counters into a + single counter that just counts the number of reasons that + the corresponding CPU is non-idle? </td></tr> <tr><th align="left">Answer:</th></tr> <tr><td bgcolor="#ffffff"><font color="ffffff"> - It seems simpler only until you think hard about how to go about - updating the <tt>rcu_dynticks</tt> structure's - <tt>->dynticks</tt> field. + Because this would fail in the presence of interrupts whose + handlers never return and of handlers that manage to return + from a made-up interrupt. </font></td></tr> <tr><td> </td></tr> </table> diff --git a/Documentation/RCU/Design/Requirements/Requirements.html b/Documentation/RCU/Design/Requirements/Requirements.html index 62e847bcdcdd..49690228b1c6 100644 --- a/Documentation/RCU/Design/Requirements/Requirements.html +++ b/ |