diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block | 10 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 6 | ||||
| -rw-r--r-- | Documentation/block/00-INDEX | 2 | ||||
| -rw-r--r-- | Documentation/block/bfq-iosched.txt | 531 | ||||
| -rw-r--r-- | Documentation/block/kyber-iosched.txt | 14 | ||||
| -rw-r--r-- | Documentation/block/queue-sysfs.txt | 11 | ||||
| -rw-r--r-- | Documentation/blockdev/mflash.txt | 84 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/pci/hisilicon-pcie.txt | 10 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/rng/omap_rng.txt | 3 | ||||
| -rw-r--r-- | Documentation/filesystems/Locking | 3 | ||||
| -rw-r--r-- | Documentation/filesystems/porting | 6 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 3 | ||||
| -rw-r--r-- | Documentation/lightnvm/pblk.txt | 21 | ||||
| -rw-r--r-- | Documentation/pinctrl.txt | 8 | ||||
| -rw-r--r-- | Documentation/process/stable-kernel-rules.rst | 2 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 63 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/devices/arm-vgic.txt | 6 |
17 files changed, 677 insertions, 106 deletions
diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block index 2da04ce6aeef..dea212db9df3 100644 --- a/Documentation/ABI/testing/sysfs-block +++ b/Documentation/ABI/testing/sysfs-block @@ -213,14 +213,8 @@ What: /sys/block/<disk>/queue/discard_zeroes_data Date: May 2011 Contact: Martin K. Petersen <martin.petersen@oracle.com> Description: - Devices that support discard functionality may return - stale or random data when a previously discarded block - is read back. This can cause problems if the filesystem - expects discarded blocks to be explicitly cleared. If a - device reports that it deterministically returns zeroes - when a discarded area is read the discard_zeroes_data - parameter will be set to one. Otherwise it will be 0 and - the result of reading a discarded area is undefined. + Will always return 0. Don't rely on any specific behavior + for discards, and don't read this file. What: /sys/block/<disk>/queue/write_same_max_bytes Date: January 2012 diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 2ba45caabada..facc20a3f962 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1725,6 +1725,12 @@ kernel and module base offset ASLR (Address Space Layout Randomization). + kasan_multi_shot + [KNL] Enforce KASAN (Kernel Address Sanitizer) to print + report on every invalid memory access. Without this + parameter KASAN will print report only for the first + invalid access. + keepinitrd [HW,ARM] kernelcore= [KNL,X86,IA-64,PPC] diff --git a/Documentation/block/00-INDEX b/Documentation/block/00-INDEX index e55103ace382..8d55b4bbb5e2 100644 --- a/Documentation/block/00-INDEX +++ b/Documentation/block/00-INDEX @@ -1,5 +1,7 @@ 00-INDEX - This file +bfq-iosched.txt + - BFQ IO scheduler and its tunables biodoc.txt - Notes on the Generic Block Layer Rewrite in Linux 2.5 biovecs.txt diff --git a/Documentation/block/bfq-iosched.txt b/Documentation/block/bfq-iosched.txt new file mode 100644 index 000000000000..1b87df6cd476 --- /dev/null +++ b/Documentation/block/bfq-iosched.txt @@ -0,0 +1,531 @@ +BFQ (Budget Fair Queueing) +========================== + +BFQ is a proportional-share I/O scheduler, with some extra +low-latency capabilities. In addition to cgroups support (blkio or io +controllers), BFQ's main features are: +- BFQ guarantees a high system and application responsiveness, and a + low latency for time-sensitive applications, such as audio or video + players; +- BFQ distributes bandwidth, and not just time, among processes or + groups (switching back to time distribution when needed to keep + throughput high). + +On average CPUs, the current version of BFQ can handle devices +performing at most ~30K IOPS; at most ~50 KIOPS on faster CPUs. As a +reference, 30-50 KIOPS correspond to very high bandwidths with +sequential I/O (e.g., 8-12 GB/s if I/O requests are 256 KB large), and +to 120-200 MB/s with 4KB random I/O. BFQ has not yet been tested on +multi-queue devices. + +The table of contents follow. Impatients can just jump to Section 3. + +CONTENTS + +1. When may BFQ be useful? + 1-1 Personal systems + 1-2 Server systems +2. How does BFQ work? +3. What are BFQ's tunable? +4. BFQ group scheduling + 4-1 Service guarantees provided + 4-2 Interface + +1. When may BFQ be useful? +========================== + +BFQ provides the following benefits on personal and server systems. + +1-1 Personal systems +-------------------- + +Low latency for interactive applications + +Regardless of the actual background workload, BFQ guarantees that, for +interactive tasks, the storage device is virtually as responsive as if +it was idle. For example, even if one or more of the following +background workloads are being executed: +- one or more large files are being read, written or copied, +- a tree of source files is being compiled, +- one or more virtual machines are performing I/O, +- a software update is in progress, +- indexing daemons are scanning filesystems and updating their + databases, +starting an application or loading a file from within an application +takes about the same time as if the storage device was idle. As a +comparison, with CFQ, NOOP or DEADLINE, and in the same conditions, +applications experience high latencies, or even become unresponsive +until the background workload terminates (also on SSDs). + +Low latency for soft real-time applications + +Also soft real-time applications, such as audio and video +players/streamers, enjoy a low latency and a low drop rate, regardless +of the background I/O workload. As a consequence, these applications +do not suffer from almost any glitch due to the background workload. + +Higher speed for code-development tasks + +If some additional workload happens to be executed in parallel, then +BFQ executes the I/O-related components of typical code-development +tasks (compilation, checkout, merge, ...) much more quickly than CFQ, +NOOP or DEADLINE. + +High throughput + +On hard disks, BFQ achieves up to 30% higher throughput than CFQ, and +up to 150% higher throughput than DEADLINE and NOOP, with all the +sequential workloads considered in our tests. With random workloads, +and with all the workloads on flash-based devices, BFQ achieves, +instead, about the same throughput as the other schedulers. + +Strong fairness, bandwidth and delay guarantees + +BFQ distributes the device throughput, and not just the device time, +among I/O-bound applications in proportion their weights, with any +workload and regardless of the device parameters. From these bandwidth +guarantees, it is possible to compute tight per-I/O-request delay +guarantees by a simple formula. If not configured for strict service +guarantees, BFQ switches to time-based resource sharing (only) for +applications that would otherwise cause a throughput loss. + +1-2 Server systems +------------------ + +Most benefits for server systems follow from the same service +properties as above. In particular, regardless of whether additional, +possibly heavy workloads are being served, BFQ guarantees: + +. audio and video-streaming with zero or very low jitter and drop + rate; + +. fast retrieval of WEB pages and embedded objects; + +. real-time recording of data in live-dumping applications (e.g., + packet logging); + +. responsiveness in local and remote access to a server. + + +2. How does BFQ work? +===================== + +BFQ is a proportional-share I/O scheduler, whose general structure, +plus a lot of code, are borrowed from CFQ. + +- Each process doing I/O on a device is associated with a weight and a + (bfq_)queue. + +- BFQ grants exclusive access to the device, for a while, to one queue + (process) at a time, and implements this service model by + associating every queue with a budget, measured in number of + sectors. + + - After a queue is granted access to the device, the budget of the + queue is decremented, on each request dispatch, by the size of the + request. + + - The in-service queue is expired, i.e., its service is suspended, + only if one of the following events occurs: 1) the queue finishes + its budget, 2) the queue empties, 3) a "budget timeout" fires. + + - The budget timeout prevents processes doing random I/O from + holding the device for too long and dramatically reducing + throughput. + + - Actually, as in CFQ, a queue associated with a process issuing + sync requests may not be expired immediately when it empties. In + contrast, BFQ may idle the device for a short time interval, + giving the process the chance to go on being served if it issues + a new request in time. Device idling typically boosts the + throughput on rotational devices, if processes do synchronous + and sequential I/O. In addition, under BFQ, device idling is + also instrumental in guaranteeing the desired throughput + fraction to processes issuing sync requests (see the description + of the slice_idle tunable in this document, or [1, 2], for more + details). + + - With respect to idling for service guarantees, if several + processes are competing for the device at the same time, but + all processes (and groups, after the following commit) have + the same weight, then BFQ guarantees the expected throughput + distribution without ever idling the device. Throughput is + thus as high as possible in this common scenario. + + - If low-latency mode is enabled (default configuration), BFQ + executes some special heuristics to detect interactive and soft + real-time applications (e.g., video or audio players/streamers), + and to reduce their latency. The most important action taken to + achieve this goal is to give to the queues associated with these + applications more than their fair share of the device + throughput. For brevity, we call just "weight-raising" the whole + sets of actions taken by BFQ to privilege these queues. In + particular, BFQ provides a milder form of weight-raising for + interactive applications, and a stronger form for soft real-time + applications. + + - BFQ automatically deactivates idling for queues born in a burst of + queue creations. In fact, these queues are usually associated with + the processes of applications and services that benefit mostly + from a high throughput. Examples are systemd during boot, or git + grep. + + - As CFQ, BFQ merges queues performing interleaved I/O, i.e., + performing random I/O that becomes mostly sequential if + merged. Differently from CFQ, BFQ achieves this goal with a more + reactive mechanism, called Early Queue Merge (EQM). EQM is so + responsive in detecting interleaved I/O (cooperating processes), + that it enables BFQ to achieve a high throughput, by queue + merging, even for queues for which CFQ needs a different + mechanism, preemption, to get a high throughput. As such EQM is a + unified mechanism to achieve a high throughput with interleaved + I/O. + + - Queues are scheduled according to a variant of WF2Q+, named + B-WF2Q+, and implemented using an augmented rb-tree to preserve an + O(log N) overall complexity. See [2] for more details. B-WF2Q+ is + also ready for hierarchical scheduling. However, for a cleaner + logical breakdown, the code that enables and completes + hierarchical support is provided in the next commit, which focuses + exactly on this feature. + + - B-WF2Q+ guarantees a tight deviation with respect to an ideal, + perfectly fair, and smooth service. In particular, B-WF2Q+ + guarantees that each queue receives a fraction of the device + throughput proportional to its weight, even if the throughput + fluctuates, and regardless of: the device parameters, the current + workload and the budgets assigned to the queue. + + - The last, budget-independence, property (although probably + counterintuitive in the first place) is definitely beneficial, for + the following reasons: + + - First, with any proportional-share scheduler, the maximum + deviation with respect to an ideal service is proportional to + the maximum budget (slice) assigned to queues. As a consequence, + BFQ can keep this deviation tight not only because of the + accurate service of B-WF2Q+, but also because BFQ *does not* + need to assign a larger budget to a queue to let the queue + receive a higher fraction of the device throughput. + + - Second, BFQ is free to choose, for every process (queue), the + budget that best fits the needs of the process, or best + leverages the I/O pattern of the process. In particular, BFQ + updates queue budgets with a simple feedback-loop algorithm that + allows a high throughput to be achieved, while still providing + tight latency guarantees to time-sensitive applications. When + the in-service queue expires, this algorithm computes the next + budget of the queue so as to: + + - Let large budgets be eventually assigned to the queues + associated with I/O-bound applications performing sequential + I/O: in fact, the longer these applications are served once + got access to the device, the higher the throughput is. + + - Let small budgets be eventually assigned to the queues + associated with time-sensitive applications (which typically + perform sporadic and short I/O), because, the smaller the + budget assigned to a queue waiting for service is, the sooner + B-WF2Q+ will serve that queue (Subsec 3.3 in [2]). + +- If several processes are competing for the device at the same time, + but all processes and groups have the same weight, then BFQ + guarantees the expected throughput distribution without ever idling + the device. It uses preemption instead. Throughput is then much + higher in this common scenario. + +- ioprio classes are served in strict priority order, i.e., + lower-priority queues are not served as long as there are + higher-priority queues. Among queues in the same class, the + bandwidth is distributed in proportion to the weight of each + queue. A very thin extra bandwidth is however guaranteed to + the Idle class, to prevent it from starving. + + +3. What are BFQ's tunable? +========================== + +The tunables back_seek-max, back_seek_penalty, fifo_expire_async and +fifo_expire_sync below are the same as in CFQ. Their description is +just copied from that for CFQ. Some considerations in the description +of slice_idle are copied from CFQ too. + +per-process ioprio and weight +----------------------------- + +Unless the cgroups interface is used (see "4. BFQ group scheduling"), +weights can be assigned to processes only indirectly, through I/O +priorities, and according to the relation: +weight = (IOPRIO_BE_NR - ioprio) * 10. + +Beware that, if low-latency is set, then BFQ automatically raises the +weight of the queues associated with interactive and soft real-time +applications. Unset this tunable if you need/want to control weights. + +slice_idle +---------- + +This parameter specifies how long BFQ should idle for next I/O +request, when certain sync BFQ queues become empty. By default +slice_idle is a non-zero value. Idling has a double purpose: boosting +throughput and making sure that the desired throughput distribution is +respected (see the description of how BFQ works, and, if needed, the +papers referred there). + +As for throughput, idling can be very helpful on highly seeky media +like single spindle SATA/SAS disks where we can cut down on overall +number of seeks and see improved throughput. + +Setting slice_idle to 0 will remove all the idling on queues and one +should see an overall improved throughput on faster storage devices +like multiple SATA/SAS disks in hardware RAID configuration. + +So depending on storage and workload, it might be useful to set +slice_idle=0. In general for SATA/SAS disks and software RAID of +SATA/SAS disks keeping slice_idle enabled should be useful. For any +configurations where there are multiple spindles behind single LUN +(Host based hardware RAID controller or for storage arrays), setting +slice_idle=0 might end up in better throughput and acceptable +latencies. + +Idling is however necessary to have service guarantees enforced in +case of differentiated weights or differentiated I/O-request lengths. +To see why, suppose that a given BFQ queue A must get several I/O +requests served for each request served for another queue B. Idling +ensures that, if A makes a new I/O request slightly after becoming +empty, then no request of B is dispatched in the middle, and thus A +does not lose the possibility to get more than one request dispatched +before the next request of B is dispatched. Note that idling +guarantees the desired differentiated treatment of queues only in +terms of I/O-request dispatches. To guarantee that the actual service +order then corresponds to the dispatch order, the strict_guarantees +tunable must be set too. + +There is an important flipside for idling: apart from the above cases +where it is beneficial also for throughput, idling can severely impact +throughput. One important case is random workload. Because of this +issue, BFQ tends to avoid idling as much as possible, when it is not +beneficial also for throughput. As a consequence of this behavior, and +of further issues described for the strict_guarantees tunable, +short-term service guarantees may be occasionally violated. And, in +some cases, these guarantees may be more important than guaranteeing +maximum throughput. For example, in video playing/streaming, a very +low drop rate may be more important than maximum throughput. In these +cases, consider setting the strict_guarantees parameter. + +strict_guarantees +----------------- + +If this parameter is set (default: unset), then BFQ + +- always performs idling when the in-service queue becomes empty; + +- forces the device to serve one I/O request at a time, by dispatching a + new request only if there is no outstanding request. + +In the presence of differentiated weights or I/O-request sizes, both +the above conditions are needed to guarantee that every BFQ queue +receives its allotted share of the bandwidth. The first condition is +needed for the reasons explained in the description of the slice_idle +tunable. The second condition is needed because all modern storage +devices reorder internally-queued requests, which may trivially break +the service guarantees enforced by the I/O scheduler. + +Setting strict_guarantees may evidently affect throughput. + +back_seek_max +------------- + +This specifies, given in Kbytes, the maximum "distance" for backward seeking. +The distance is the amount of space from the current head location to the +sectors that are backward in terms of distance. + +This parameter allows the scheduler to anticipate requests in the "backward" +direction and consider them as being the "next" if they are within this +distance from the current head location. + +back_seek_penalty +----------------- + +This parameter is used to compute the cost of backward seeking. If the +backward distance of request is just 1/back_seek_penalty from a "front" +request, then the seeking cost of two requests is considered equivalent. + +So scheduler will not bias toward one or the other request (otherwise scheduler +will bias toward front request). Default value of back_seek_penalty is 2. + +fifo_expire_async +----------------- + +This parameter is used to set the timeout of asynchronous requests. Default +value of this is 248ms. + +fifo_expire_sync +---------------- + +This parameter is used to set the timeout of synchronous requests. Default +value of this is 124ms. In case to favor synchronous requests over asynchronous +one, this value should be decreased relative to fifo_expire_async. + +low_latency +----------- + +This parameter is used to enable/disable BFQ's low latency mode. By +default, low latency mode is enabled. If enabled, interactive and soft +real-time applications are privileged and experience a lower latency, +as explained in more detail in the description of how BFQ works. + +DO NOT enable this mode if you need full control on bandwidth +distribution. In fact, if it is enabled, then BFQ automatically +increases the bandwidth share of privileged applications, as the main +means to guarantee a lower latency to them. + +timeout_sync +------------ + +Maximum amount of device time that can be given to a task (queue) once +it has been selected for service. On devices with costly seeks, +increasing this time usually increases maximum throughput. On the +opposite end, increasing this time coarsens the granularity of the +short-term bandwidth and latency guarantees, especially if the +following parameter is set to zero. + +max_budget +---------- + +Maximum amount of service, measured in sectors, that can be provided +to a BFQ queue once it is set in service (of course within the limits +of the above timeout). According to what said in the description of +the algorithm, larger values increase the throughput in proportion to +the percentage of sequential I/O requests issued. The price of larger +values is that they coarsen the granularity of short-term bandwidth +and latency guarantees. + +The default value is 0, which enables auto-tuning: BFQ sets max_budget +to the maximum number of sectors that can be served during +timeout_sync, according to the estimated peak rate. + +weights +------- + +Read-only parameter, used to show the weights of the currently active +BFQ queues. + + +wr_ tunables +------------ + +BFQ exports a few parameters to control/tune the behavior of +low-latency heuristics. + +wr_coeff + +Factor by which the weight of a weight-raised queue is multiplied. If +the queue is deemed soft real-time, then the weight is further +multiplied by an additional, constant factor. + +wr_max_time + +Maximum duration of a weight-raising period for an interactive task +(ms). If set to zero (default value), then this value is computed +automatically, as a function of the peak rate of the device. In any +case, when the value of this parameter is read, it always reports the +current duration, regardless of whether it has been set manually or +computed automatically. + +wr_max_softrt_rate + +Maximum service rate below which a queue is deemed to be associated +with a soft real-time application, and is then weight-raised +accordingly (sectors/sec). + +wr_min_idle_time + +Minimum idle period after which interactive weight-raising may be +reactivated for a queue (in ms). + +wr_rt_max_time + +Maximum weight-raising duration for soft real-time queues (in ms). The +start time from which this duration is considered is automatically +moved forward if the queue is detected to be still soft real-time +before the current soft real-time weight-raising period finishes. + +wr_min_inter_arr_async + +Minimum period between I/O request arrivals after which weight-raising +may be reactivated for an already busy async queue (in ms). + + +4. Group scheduling with BFQ +============================ + +BFQ supports both cgroups-v1 and cgroups-v2 io controllers, namely +blkio and io. In particular, BFQ supports weight-based proportional +share. To activate cgroups support, set BFQ_GROUP_IOSCHED. + +4-1 Service guarantees provided +------------------------------- + +With BFQ, proportional share means true proportional share of the +device bandwidth, according to group weights. For example, a group +with weight 200 gets twice the bandwidth, and not just twice the time, +of a group with weight 100. + +BFQ supports hierarchies (group trees) of any depth. Bandwidth is +distributed among groups and processes in the expected way: for each +group, the children of the group share the whole bandwidth of the +group in proportion to their weights. In particular, this implies +that, for each leaf group, every process of the group receives the +same share of the whole group bandwidth, unless the ioprio of the +process is modified. + +The resource-sharing guarantee for a group may partially or totally +switch from bandwidth to time, if providing bandwidth guarantees to +the group lowers the throughput too much. This switch occurs on a +per-process basis: if a process of a leaf group causes throughput loss +if served in such a way to receive its share of the bandwidth, then +BFQ switches back to just time-based proportional share for that +process. + +4-2 Interface +------------- + +To get proportional sharing of bandwidth with BFQ for a given device, +BFQ must of course be the active scheduler for that device. + +Within each group directory, the names of the files associated with +BFQ-specific cgroup parameters and stats begin with the "bfq." +prefix. So, with cgroups-v1 or cgroups-v2, the full prefix for +BFQ-specific files is "blkio.bfq." or "io.bfq." For example, the group +parameter to set the weight of a group with BFQ is blkio.bfq.weight +or io.bfq.weight. + +Parameters to set +----------------- + +For each group, there is only the following parameter to set. + +weight (namely blkio.bfq.weight or io.bfq-weight): the weight of the +group inside its parent. Available values: 1..10000 (default 100). The +linear mapping between ioprio and weights, described at the beginning +of the tunable section, is still valid, but all weights higher than +IOPRIO_BE_NR*10 are mapped to ioprio 0. + +Recall that, if low-latency is set, then BFQ automatically raises the +weight of the queues associated with interactive and soft real-time +applications. Unset this tunable if you need/want to control weights. + + +[1] P. Valente, A. Avanzini, "Evolution of the BFQ Storage I/O + Scheduler", Proceedings of the First Workshop on Mobile System + Technologies (MST-2015), May 2015. + http://algogroup.unimore.it/people/paolo/disk_sched/mst-2015.pdf + +[2] P. Valente and M. Andreolini, "Improving Application + Responsiveness with the BFQ Disk I/O Scheduler", Proceedings of + the 5th Annual International Systems and Storage Conference + (SYSTOR '12), June 2012. + Slightly extended version: + http://algogroup.unimore.it/people/paolo/disk_sched/bfq-v1-suite- + results.pdf diff --git a/Documentation/block/kyber-iosched.txt b/Documentation/block/kyber-iosched.txt new file mode 100644 index 000000000000..e94feacd7edc --- /dev/null +++ b/Documentation/block/kyber-iosched.txt @@ -0,0 +1,14 @@ +Kyber I/O scheduler tunables +=========================== + +The only two tunables for the Kyber scheduler are the target latencies for +reads and synchronous writes. Kyber will throttle requests in order to meet +these target latencies. + +read_lat_nsec +------------- +Target latency for reads (in nanoseconds). + +write_lat_nsec +-------------- +Target latency for synchronous writes (in nanoseconds). diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt index c0a3bb5a6e4e..2c1e67058fd3 100644 --- a/Documentation/block/queue-sysfs.txt +++ b/Documentation/block/queue-sysfs.txt @@ -43,11 +43,6 @@ large discards are issued, setting this value lower will make Linux issue smaller discards and potentially help reduce latencies induced by large discard operations. -discard_zeroes_data (RO) ------------------------- -When read, this file will show if the discarded block are zeroed by the -device or not. If its value is '1' the blocks are zeroed otherwise not. - hw_sector_size (RO) ------------------- This is the hardware sector size of the device, in bytes. @@ -192,5 +187,11 @@ scaling back writes. Writing a value of '0' to this file disables the feature. Writing a value of '-1' to this file resets the value to the default setting. +throttle_sample_time (RW) +------------------------- +This is the time window that blk-throttle samples data, in millisecond. +blk-throttle makes decision based on the samplings. Lower time means cgroups +have more smooth throughput, but higher CPU overhead. This exists only when +CONFIG_BLK_DEV_THROTTLING_LOW is enabled. Jens Axboe <jens.axboe@oracle.com>, February 2009 diff --git a/Documentation/blockdev/mflash.txt b/Documentation/blockdev/mflash.txt deleted file mode 100644 index f7e050551487..000000000000 --- a/Documentation/blockdev/mflash.txt +++ /dev/null @@ -1,84 +0,0 @@ -This document describes m[g]flash support in linux. - -Contents - 1. Overview - 2. Reserved area configuration - 3. Example of mflash platform driver registration - -1. Overview - -Mflash and gflash are embedded flash drive. The only difference is mflash is -MCP(Multi Chip Package) device. These two device operate exactly same way. -So the rest mflash repersents mflash and gflash altogether. - -Internally, mflash has nand flash and other hardware logics and supports -2 different operation (ATA, IO) modes. ATA mode doesn't need any new -driver and currently works well under standard IDE subsystem. Actually it's -one chip SSD. IO mode is ATA-like custom mode for the host that doesn't have -IDE interface. - -Following are brief descriptions about IO mode. -A. IO mode based on ATA protocol and uses some custom command. (read confirm, -write confirm) -B. IO mode uses SRAM bus interface. -C. IO mode supports 4kB boot area, so host can boot from mflash. - -2. Reserved area configuration -If host boot from mflash, usually needs raw area for boot loader image. All of -the mflash's block device operation will be taken this value as start offset. -Note that boot loader's size of reserved area and kernel configuration value -must be same. - -3. Example of mflash platform driver registration -Working mflash is very straight forward. Adding platform device stuff to board -configuration file is all. Here is some pseudo example. - -static struct mg_drv_data mflash_drv_data = { - /* If you want to polling driver set to 1 */ - .use_polling = 0, - /* device attribution */ - .dev_attr = MG_BOOT_DEV -}; - -static struct resource mg_mflash_rsc[] = { - /* Base address of mflash */ - [0] = { - .start = 0x08000000, - .end = 0x08000000 + SZ_64K - 1, - .flags = IORESOURCE_MEM - }, - /* mflash interrupt pin */ - [1] = { - .start = IRQ_GPIO(84), - .end = IRQ_GPIO(84), - .flags = IORESOURCE_IRQ - }, - /* mflash reset pin */ - [2] = { - .start = 43, - .end = 43, - .name = MG_RST_PIN, - .flags = IORESOURCE_IO - }, - /* mflash reset-out pin - * If you use mflash as storage device (i.e. other than MG_BOOT_DEV), - * should assign this */ - [3] = { - .start = 51, - .end = 51, - .name = MG_RSTOUT_PIN, - .flags = IORESOURCE_IO - } -}; - -static struct platform_device mflash_dev = { - .name = MG_DEV_NAME, - .id = -1, - .dev = { - .platform_data = &mflash_drv_data, - }, - .num_resources = ARRAY_SIZE(mg_mflash_rsc), - .resource = mg_mflash_rsc -}; - -platform_device_register(&mflash_dev); diff --git a/Documentation/devicetree/bindings/pci/hisilicon-pcie.txt b/Documentation/devicetree/bindings/pci/hisilicon-pcie.txt index b7fa3b97986d..a339dbb15493 100644 --- a/Documentation/devicetree/bindings/pci/hisilicon-pcie.txt +++ b/Documentation/devicetree/bindings/pci/hisilicon-pcie.txt @@ -44,13 +44,19 @@ Hip05 Example (note that Hip06 is the same except compatible): }; HiSilicon Hip06/Hip07 PCIe host bridge DT (almost-ECAM) description. + +Some BIOSes place the host controller in a mode where it is ECAM +compliant for all devices other than the root complex. In such cases, +the host controller should be described as below. + The properties and their meanings are identical to those described in host-generic-pci.txt except as listed below. Properties of the host controller node that differ from host-generic-pci.txt: -- compatible : Must be "hisilicon,pcie-almost-ecam" +- compatible : Must be "hisilicon,hip06-pcie-ecam", or + "hisilicon,hip07-pcie-ecam" - reg : Two entries: First the ECAM configuration space for any other bus underneath the root bus. Second, the base @@ -59,7 +65,7 @@ host-generic-pci.txt: Example: pcie0: pcie@a0090000 { - compatible = "hisilicon,pcie-almost-ecam"; + compatible = "hisilicon,hip06-pcie-ecam"; reg = <0 0xb0000000 0 0x2000000>, /* ECAM configuration space */ <0 0xa0090000 0 0x10000>; /* host bridge registers */ bus-range = <0 31>; diff --git a/Documentation/devicetree/bindings/rng/omap_rng.txt b/Documentation/devicetree/bindings/rng/omap_rng.txt index 471477299ece..9cf7876ab434 100644 --- a/Documentation/devicetree/bindings/rng/omap_rng.txt +++ b/Documentation/devicetree/bindings/rng/omap_rng.txt @@ -12,7 +12,8 @@ Required properties: - reg : Offset and length of the register set for the module - interrupts : the interrupt number for the RNG module. Used for "ti,omap4-rng" and "inside-secure,safexcel-eip76" -- clocks: the trng clock source +- clocks: the trng clock source. Only mandatory for the + "inside-secure,safexcel-eip76" compatible. Example: /* AM335x */ diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index fdcfdd79682a..fe25787ff6d4 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -58,8 +58,7 @@ prototypes: int (*permission) (struct inode *, int, unsigned int); int (*get_acl)(struct inode *, int); int (*setattr) (struct dentry *, struct iattr *); - int (*getattr) (const struct path *, struct dentry *, struct kstat *, - u32, unsigned int); + int (*getattr) (const struct path *, struct kstat *, u32, unsigned int); ssize_t (*listxattr) (struct dentry *, char *, size_t); int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, u64 len); void (*update_time)(struct inode *, struct timespec *, int); diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 95280079c0b3..5fb17f49f7a2 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -600,3 +600,9 @@ in your dentry operations instead. [recommended] ->readlink is optional for symlinks. Don't set, unless filesystem needs to fake something for readlink(2). +-- +[mandatory] + ->getattr() is now passed a struct path rather than a vfsmount and + dentry separately, and it now has request_mask and query_flags arguments + to specify the fields and sync type requested by statx. Filesystems not + supporting any statx-specific features may ignore the new arguments. diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 569211703721..94dd27ef4a76 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -382,8 +382,7 @@ struct inode_operations { int (*permission) (struct inode *, int); int (*get_acl)(struct inode *, int); int (*setattr) (struct dentry *, struct iattr *); - int (*getattr) (const struct path *, struct dentry *, struct kstat *, - u32, unsigned int); + int (*getattr) (const struct path *, struct kstat *, u32, unsigned int); ssize_t (*listxattr) (struct dentry *, char *, size_t); void (*update_time)(struct inode *, struct timespec *, int); int (*atomic_open)(struct inode *, struct dentry *, struct file *, diff --git a/Documentation/lightnvm/pblk.txt b/Documentation/lightnvm/pblk.txt new file mode 100644 index 000000000000..1040ed1cec81 --- /dev/null +++ b/Documentation/lightnvm/pblk.txt @@ -0,0 +1,21 @@ +pblk: Physical Block Device Target +================================== + +pblk implements a fully associative, host-based FTL that exposes a traditional +block I/O interface. Its primary responsibilities are: + + - Map logical addresses onto physical addresses (4KB granularity) in a + logical-to-physical (L2P) table. + - Maintain the integrity and consistency of the L2P table as well as its + recovery from normal tear down and power outage. + - Deal with controller- and media-specific constrains. + - Handle I/O errors. + - Implement garbage collection. + - Maintain consistency across the I/O stack during synchronization points. + +For more information please refer to: + + http://lightnvm.io + +which maintains updated FAQs, manual pages, technical documentation, tools, +contacts, etc. diff --git a/Documentation/pinctrl.txt b/Documentation/pinctrl.txt index 54bd5faa8782..f2af35f6d6b2 100644 --- a/Documentation/pinctrl.txt +++ b/Documentation/pinctrl.txt @@ -77,9 +77,15 @@ static struct pinctrl_desc foo_desc = { int __init foo_probe(void) { + int error; + struct pinctrl_dev *pctl; - return pinctrl_register_and_init(&foo_desc, <PARENT>, NULL, &pctl); + error = pinctrl_register_and_init(&foo_desc, <PARENT>, NULL, &pctl); + if (error) + return error; + + return pinctrl_enable(pctl); } To enable the pinctrl subsystem and the subgroups for PINMUX and PINCONF and diff --git a/Documentation/process/stable-kernel-rules.rst b/Documentation/process/stable-kernel-rules.rst index 11ec2d93a5e0..61e9c78bd6d1 100644 --- a/Documentation/process/stable-kernel-rules.rst +++ b/Documentation/process/stable-kernel-rules.rst @@ -124,7 +124,7 @@ specified in the following format in the sign-off area: .. code-block:: none - Cc: <stable@vger.kernel.org> # 3.3.x- + Cc: <stable@vger.kernel.org> # 3.3.x The tag has the meaning of: diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 3c248f772ae6..fd106899afd1 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3377,6 +3377,69 @@ struct kvm_ppc_resize_hpt { __u32 pad; }; +4.104 KVM_X86_GET_MCE_CAP_SUPPORTED + +Capability: KVM_CAP_MCE +Architectures: x86 +Type: system ioctl +Parameters: u64 mce_cap (out) +Returns: 0 on success, -1 on error + +Returns supported MCE capabilities. The u64 mce_cap parameter +has the same format as the MSR_IA32_MCG_CAP register. Supported +capabilities will have the corresponding bits set. + +4.105 KVM_X86_SETUP_MCE + +Capability: KVM_CAP_MCE +Architectures: x86 +Type: vcpu ioctl +Parameters: u64 mcg_cap (in) +Returns: 0 on success, + -EFAULT if u64 mcg_cap cannot be read, + -EINVAL if the requested number of banks is invalid, + -EINVAL if requested MCE capability is not supported. + +Initializes MCE support for use. The u64 mcg_cap parameter +has the same format as the MSR_IA32_MCG_CAP register and +specifies which capabilities should be enabled. The maximum +supported number of error-reporting banks can be retrieved when +checking for KVM_CAP_MCE. The supported capabilities can be +retrieved with KVM_X86_GET_MCE_CAP_SUPPORTED. + +4.106 KVM_X86_SET_MCE + +Capability: KVM_CAP_MCE +Architectures: x86 +Type: vcpu ioctl +Parameters: struct kvm_x86_mce (in) +Returns: 0 on success, + -EFAULT if struct kvm_x86_mce cannot be read, + -EINVAL if the bank number is invalid, + -EINVAL if VAL bit is not set in status field. + +Inject a machine check error (MCE) into the guest. The input +parameter is: + +struct kvm_x86_mce { + __u64 status; + __u64 addr; + __u64 misc; + __u64 mcg_status; + __u8 bank; + __u8 pad1[7]; + __u64 pad2[3]; +}; + +If the MCE being reported is an uncorrected error, KVM will +inject it as an MCE exception into the guest. If the guest +MCG_STATUS register reports that an MCE is in progress, KVM +causes an KVM_EXIT_SHUTDOWN vmexit. + +Otherwise, if the MCE is a corrected error, KVM will just +store it in the corresponding bank (provided this bank is +not holding a previously reported uncorrected error). + 5. The kvm_run structure ------------------------ diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt index 76e61c883347..b2f60ca8b60c 100644 --- a/Documentation/virtual/kvm/devices/arm-vgic.txt +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt @@ -83,6 +83,12 @@ Groups: Bits for undefined preemption levels are RAZ/WI. + For historical reasons and to provide ABI compatibility with userspace we + export the GICC_PMR register in the format of the GICH_VMCR.VMPriMask + field in the lower 5 bits of a word, meaning that userspace must always + use the lower 5 bits to communicate with the KVM device and must shift the + value left by 3 places to obtain the actual priority mask level. + Limitations: - Priorities are not implemented, and registers are RAZ/WI - Currently only implemented for KVM_DEV_TYPE_ARM_VGIC_V2. |