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-rw-r--r--Documentation/ABI/testing/sysfs-bus-usb2
-rw-r--r--Documentation/DMA-API-HOWTO.txt (renamed from Documentation/PCI/PCI-DMA-mapping.txt)0
-rw-r--r--Documentation/cgroups/memory.txt2
-rw-r--r--Documentation/circular-buffers.txt234
-rw-r--r--Documentation/connector/cn_test.c1
-rw-r--r--Documentation/filesystems/00-INDEX2
-rw-r--r--Documentation/filesystems/9p.txt18
-rw-r--r--Documentation/filesystems/ceph.txt140
-rw-r--r--Documentation/filesystems/tmpfs.txt6
-rw-r--r--Documentation/ioctl/ioctl-number.txt1
-rw-r--r--Documentation/kobject.txt60
-rw-r--r--Documentation/memory-barriers.txt20
-rw-r--r--Documentation/networking/stmmac.txt143
-rw-r--r--Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt54
-rw-r--r--Documentation/volatile-considered-harmful.txt6
15 files changed, 661 insertions, 28 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb
index a986e9bbba3d..bcebb9eaedce 100644
--- a/Documentation/ABI/testing/sysfs-bus-usb
+++ b/Documentation/ABI/testing/sysfs-bus-usb
@@ -160,7 +160,7 @@ Description:
160 match the driver to the device. For example: 160 match the driver to the device. For example:
161 # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id 161 # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id
162 162
163What: /sys/bus/usb/device/.../avoid_reset 163What: /sys/bus/usb/device/.../avoid_reset_quirk
164Date: December 2009 164Date: December 2009
165Contact: Oliver Neukum <oliver@neukum.org> 165Contact: Oliver Neukum <oliver@neukum.org>
166Description: 166Description:
diff --git a/Documentation/PCI/PCI-DMA-mapping.txt b/Documentation/DMA-API-HOWTO.txt
index 52618ab069ad..52618ab069ad 100644
--- a/Documentation/PCI/PCI-DMA-mapping.txt
+++ b/Documentation/DMA-API-HOWTO.txt
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index f8bc802d70b9..3a6aecd078ba 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -340,7 +340,7 @@ Note:
3405.3 swappiness 3405.3 swappiness
341 Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only. 341 Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only.
342 342
343 Following cgroups' swapiness can't be changed. 343 Following cgroups' swappiness can't be changed.
344 - root cgroup (uses /proc/sys/vm/swappiness). 344 - root cgroup (uses /proc/sys/vm/swappiness).
345 - a cgroup which uses hierarchy and it has child cgroup. 345 - a cgroup which uses hierarchy and it has child cgroup.
346 - a cgroup which uses hierarchy and not the root of hierarchy. 346 - a cgroup which uses hierarchy and not the root of hierarchy.
diff --git a/Documentation/circular-buffers.txt b/Documentation/circular-buffers.txt
new file mode 100644
index 000000000000..8117e5bf6065
--- /dev/null
+++ b/Documentation/circular-buffers.txt
@@ -0,0 +1,234 @@
1 ================
2 CIRCULAR BUFFERS
3 ================
4
5By: David Howells <dhowells@redhat.com>
6 Paul E. McKenney <paulmck@linux.vnet.ibm.com>
7
8
9Linux provides a number of features that can be used to implement circular
10buffering. There are two sets of such features:
11
12 (1) Convenience functions for determining information about power-of-2 sized
13 buffers.
14
15 (2) Memory barriers for when the producer and the consumer of objects in the
16 buffer don't want to share a lock.
17
18To use these facilities, as discussed below, there needs to be just one
19producer and just one consumer. It is possible to handle multiple producers by
20serialising them, and to handle multiple consumers by serialising them.
21
22
23Contents:
24
25 (*) What is a circular buffer?
26
27 (*) Measuring power-of-2 buffers.
28
29 (*) Using memory barriers with circular buffers.
30 - The producer.
31 - The consumer.
32
33
34==========================
35WHAT IS A CIRCULAR BUFFER?
36==========================
37
38First of all, what is a circular buffer? A circular buffer is a buffer of
39fixed, finite size into which there are two indices:
40
41 (1) A 'head' index - the point at which the producer inserts items into the
42 buffer.
43
44 (2) A 'tail' index - the point at which the consumer finds the next item in
45 the buffer.
46
47Typically when the tail pointer is equal to the head pointer, the buffer is
48empty; and the buffer is full when the head pointer is one less than the tail
49pointer.
50
51The head index is incremented when items are added, and the tail index when
52items are removed. The tail index should never jump the head index, and both
53indices should be wrapped to 0 when they reach the end of the buffer, thus
54allowing an infinite amount of data to flow through the buffer.
55
56Typically, items will all be of the same unit size, but this isn't strictly
57required to use the techniques below. The indices can be increased by more
58than 1 if multiple items or variable-sized items are to be included in the
59buffer, provided that neither index overtakes the other. The implementer must
60be careful, however, as a region more than one unit in size may wrap the end of
61the buffer and be broken into two segments.
62
63
64============================
65MEASURING POWER-OF-2 BUFFERS
66============================
67
68Calculation of the occupancy or the remaining capacity of an arbitrarily sized
69circular buffer would normally be a slow operation, requiring the use of a
70modulus (divide) instruction. However, if the buffer is of a power-of-2 size,
71then a much quicker bitwise-AND instruction can be used instead.
72
73Linux provides a set of macros for handling power-of-2 circular buffers. These
74can be made use of by:
75
76 #include <linux/circ_buf.h>
77
78The macros are:
79
80 (*) Measure the remaining capacity of a buffer:
81
82 CIRC_SPACE(head_index, tail_index, buffer_size);
83
84 This returns the amount of space left in the buffer[1] into which items
85 can be inserted.
86
87
88 (*) Measure the maximum consecutive immediate space in a buffer:
89
90 CIRC_SPACE_TO_END(head_index, tail_index, buffer_size);
91
92 This returns the amount of consecutive space left in the buffer[1] into
93 which items can be immediately inserted without having to wrap back to the
94 beginning of the buffer.
95
96
97 (*) Measure the occupancy of a buffer:
98
99 CIRC_CNT(head_index, tail_index, buffer_size);
100
101 This returns the number of items currently occupying a buffer[2].
102
103
104 (*) Measure the non-wrapping occupancy of a buffer:
105
106 CIRC_CNT_TO_END(head_index, tail_index, buffer_size);
107
108 This returns the number of consecutive items[2] that can be extracted from
109 the buffer without having to wrap back to the beginning of the buffer.
110
111
112Each of these macros will nominally return a value between 0 and buffer_size-1,
113however:
114
115 [1] CIRC_SPACE*() are intended to be used in the producer. To the producer
116 they will return a lower bound as the producer controls the head index,
117 but the consumer may still be depleting the buffer on another CPU and
118 moving the tail index.
119
120 To the consumer it will show an upper bound as the producer may be busy
121 depleting the space.
122
123 [2] CIRC_CNT*() are intended to be used in the consumer. To the consumer they
124 will return a lower bound as the consumer controls the tail index, but the
125 producer may still be filling the buffer on another CPU and moving the
126 head index.
127
128 To the producer it will show an upper bound as the consumer may be busy
129 emptying the buffer.
130
131 [3] To a third party, the order in which the writes to the indices by the
132 producer and consumer become visible cannot be guaranteed as they are
133 independent and may be made on different CPUs - so the result in such a
134 situation will merely be a guess, and may even be negative.
135
136
137===========================================
138USING MEMORY BARRIERS WITH CIRCULAR BUFFERS
139===========================================
140
141By using memory barriers in conjunction with circular buffers, you can avoid
142the need to:
143
144 (1) use a single lock to govern access to both ends of the buffer, thus
145 allowing the buffer to be filled and emptied at the same time; and
146
147 (2) use atomic counter operations.
148
149There are two sides to this: the producer that fills the buffer, and the
150consumer that empties it. Only one thing should be filling a buffer at any one
151time, and only one thing should be emptying a buffer at any one time, but the
152two sides can operate simultaneously.
153
154
155THE PRODUCER
156------------
157
158The producer will look something like this:
159
160 spin_lock(&producer_lock);
161
162 unsigned long head = buffer->head;
163 unsigned long tail = ACCESS_ONCE(buffer->tail);
164
165 if (CIRC_SPACE(head, tail, buffer->size) >= 1) {
166 /* insert one item into the buffer */
167 struct item *item = buffer[head];
168
169 produce_item(item);
170
171 smp_wmb(); /* commit the item before incrementing the head */
172
173 buffer->head = (head + 1) & (buffer->size - 1);
174
175 /* wake_up() will make sure that the head is committed before
176 * waking anyone up */
177 wake_up(consumer);
178 }
179
180 spin_unlock(&producer_lock);
181
182This will instruct the CPU that the contents of the new item must be written
183before the head index makes it available to the consumer and then instructs the
184CPU that the revised head index must be written before the consumer is woken.
185
186Note that wake_up() doesn't have to be the exact mechanism used, but whatever
187is used must guarantee a (write) memory barrier between the update of the head
188index and the change of state of the consumer, if a change of state occurs.
189
190
191THE CONSUMER
192------------
193
194The consumer will look something like this:
195
196 spin_lock(&consumer_lock);
197
198 unsigned long head = ACCESS_ONCE(buffer->head);
199 unsigned long tail = buffer->tail;
200
201 if (CIRC_CNT(head, tail, buffer->size) >= 1) {
202 /* read index before reading contents at that index */
203 smp_read_barrier_depends();
204
205 /* extract one item from the buffer */
206 struct item *item = buffer[tail];
207
208 consume_item(item);
209
210 smp_mb(); /* finish reading descriptor before incrementing tail */
211
212 buffer->tail = (tail + 1) & (buffer->size - 1);
213 }
214
215 spin_unlock(&consumer_lock);
216
217This will instruct the CPU to make sure the index is up to date before reading
218the new item, and then it shall make sure the CPU has finished reading the item
219before it writes the new tail pointer, which will erase the item.
220
221
222Note the use of ACCESS_ONCE() in both algorithms to read the opposition index.
223This prevents the compiler from discarding and reloading its cached value -
224which some compilers will do across smp_read_barrier_depends(). This isn't
225strictly needed if you can be sure that the opposition index will _only_ be
226used the once.
227
228
229===============
230FURTHER READING
231===============
232
233See also Documentation/memory-barriers.txt for a description of Linux's memory
234barrier facilities.
diff --git a/Documentation/connector/cn_test.c b/Documentation/connector/cn_test.c
index b07add3467f1..7764594778d4 100644
--- a/Documentation/connector/cn_test.c
+++ b/Documentation/connector/cn_test.c
@@ -25,6 +25,7 @@
25#include <linux/module.h> 25#include <linux/module.h>
26#include <linux/moduleparam.h> 26#include <linux/moduleparam.h>
27#include <linux/skbuff.h> 27#include <linux/skbuff.h>
28#include <linux/slab.h>
28#include <linux/timer.h> 29#include <linux/timer.h>
29 30
30#include <linux/connector.h> 31#include <linux/connector.h>
diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX
index 3bae418c6ad3..4303614b5add 100644
--- a/Documentation/filesystems/00-INDEX
+++ b/Documentation/filesystems/00-INDEX
@@ -16,6 +16,8 @@ befs.txt
16 - information about the BeOS filesystem for Linux. 16 - information about the BeOS filesystem for Linux.
17bfs.txt 17bfs.txt
18 - info for the SCO UnixWare Boot Filesystem (BFS). 18 - info for the SCO UnixWare Boot Filesystem (BFS).
19ceph.txt
20 - info for the Ceph Distributed File System
19cifs.txt 21cifs.txt
20 - description of the CIFS filesystem. 22 - description of the CIFS filesystem.
21coda.txt 23coda.txt
diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt
index 57e0b80a5274..c0236e753bc8 100644
--- a/Documentation/filesystems/9p.txt
+++ b/Documentation/filesystems/9p.txt
@@ -37,6 +37,15 @@ For Plan 9 From User Space applications (http://swtch.com/plan9)
37 37
38 mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER 38 mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
39 39
40For server running on QEMU host with virtio transport:
41
42 mount -t 9p -o trans=virtio <mount_tag> /mnt/9
43
44where mount_tag is the tag associated by the server to each of the exported
45mount points. Each 9P export is seen by the client as a virtio device with an
46associated "mount_tag" property. Available mount tags can be
47seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
48
40OPTIONS 49OPTIONS
41======= 50=======
42 51
@@ -47,7 +56,7 @@ OPTIONS
47 fd - used passed file descriptors for connection 56 fd - used passed file descriptors for connection
48 (see rfdno and wfdno) 57 (see rfdno and wfdno)
49 virtio - connect to the next virtio channel available 58 virtio - connect to the next virtio channel available
50 (from lguest or KVM with trans_virtio module) 59 (from QEMU with trans_virtio module)
51 rdma - connect to a specified RDMA channel 60 rdma - connect to a specified RDMA channel
52 61
53 uname=name user name to attempt mount as on the remote server. The 62 uname=name user name to attempt mount as on the remote server. The
@@ -85,7 +94,12 @@ OPTIONS
85 94
86 port=n port to connect to on the remote server 95 port=n port to connect to on the remote server
87 96
88 noextend force legacy mode (no 9p2000.u semantics) 97 noextend force legacy mode (no 9p2000.u or 9p2000.L semantics)
98
99 version=name Select 9P protocol version. Valid options are:
100 9p2000 - Legacy mode (same as noextend)
101 9p2000.u - Use 9P2000.u protocol
102 9p2000.L - Use 9P2000.L protocol
89 103
90 dfltuid attempt to mount as a particular uid 104 dfltuid attempt to mount as a particular uid
91 105
diff --git a/Documentation/filesystems/ceph.txt b/Documentation/filesystems/ceph.txt
new file mode 100644
index 000000000000..0660c9f5deef
--- /dev/null
+++ b/Documentation/filesystems/ceph.txt
@@ -0,0 +1,140 @@
1Ceph Distributed File System
2============================
3
4Ceph is a distributed network file system designed to provide good
5performance, reliability, and scalability.
6
7Basic features include:
8
9 * POSIX semantics
10 * Seamless scaling from 1 to many thousands of nodes
11 * High availability and reliability. No single point of failure.
12 * N-way replication of data across storage nodes
13 * Fast recovery from node failures
14 * Automatic rebalancing of data on node addition/removal
15 * Easy deployment: most FS components are userspace daemons
16
17Also,
18 * Flexible snapshots (on any directory)
19 * Recursive accounting (nested files, directories, bytes)
20
21In contrast to cluster filesystems like GFS, OCFS2, and GPFS that rely
22on symmetric access by all clients to shared block devices, Ceph
23separates data and metadata management into independent server
24clusters, similar to Lustre. Unlike Lustre, however, metadata and
25storage nodes run entirely as user space daemons. Storage nodes
26utilize btrfs to store data objects, leveraging its advanced features
27(checksumming, metadata replication, etc.). File data is striped
28across storage nodes in large chunks to distribute workload and
29facilitate high throughputs. When storage nodes fail, data is
30re-replicated in a distributed fashion by the storage nodes themselves
31(with some minimal coordination from a cluster monitor), making the
32system extremely efficient and scalable.
33
34Metadata servers effectively form a large, consistent, distributed
35in-memory cache above the file namespace that is extremely scalable,
36dynamically redistributes metadata in response to workload changes,
37and can tolerate arbitrary (well, non-Byzantine) node failures. The
38metadata server takes a somewhat unconventional approach to metadata
39storage to significantly improve performance for common workloads. In
40particular, inodes with only a single link are embedded in
41directories, allowing entire directories of dentries and inodes to be
42loaded into its cache with a single I/O operation. The contents of
43extremely large directories can be fragmented and managed by
44independent metadata servers, allowing scalable concurrent access.
45
46The system offers automatic data rebalancing/migration when scaling
47from a small cluster of just a few nodes to many hundreds, without
48requiring an administrator carve the data set into static volumes or
49go through the tedious process of migrating data between servers.
50When the file system approaches full, new nodes can be easily added
51and things will "just work."
52
53Ceph includes flexible snapshot mechanism that allows a user to create
54a snapshot on any subdirectory (and its nested contents) in the
55system. Snapshot creation and deletion are as simple as 'mkdir
56.snap/foo' and 'rmdir .snap/foo'.
57
58Ceph also provides some recursive accounting on directories for nested
59files and bytes. That is, a 'getfattr -d foo' on any directory in the
60system will reveal the total number of nested regular files and
61subdirectories, and a summation of all nested file sizes. This makes
62the identification of large disk space consumers relatively quick, as
63no 'du' or similar recursive scan of the file system is required.
64
65
66Mount Syntax
67============
68
69The basic mount syntax is:
70
71 # mount -t ceph monip[:port][,monip2[:port]...]:/[subdir] mnt
72
73You only need to specify a single monitor, as the client will get the
74full list when it connects. (However, if the monitor you specify
75happens to be down, the mount won't succeed.) The port can be left
76off if the monitor is using the default. So if the monitor is at
771.2.3.4,
78
79 # mount -t ceph 1.2.3.4:/ /mnt/ceph
80
81is sufficient. If /sbin/mount.ceph is installed, a hostname can be
82used instead of an IP address.
83
84
85
86Mount Options
87=============
88
89 ip=A.B.C.D[:N]
90 Specify the IP and/or port the client should bind to locally.
91 There is normally not much reason to do this. If the IP is not
92 specified, the client's IP address is determined by looking at the
93 address it's connection to the monitor originates from.
94
95 wsize=X
96 Specify the maximum write size in bytes. By default there is no
97 maximum. Ceph will normally size writes based on the file stripe
98 size.
99
100 rsize=X
101 Specify the maximum readahead.
102
103 mount_timeout=X
104 Specify the timeout value for mount (in seconds), in the case
105 of a non-responsive Ceph file system. The default is 30
106 seconds.
107
108 rbytes
109 When stat() is called on a directory, set st_size to 'rbytes',
110 the summation of file sizes over all files nested beneath that
111 directory. This is the default.
112
113 norbytes
114 When stat() is called on a directory, set st_size to the
115 number of entries in that directory.
116
117 nocrc
118 Disable CRC32C calculation for data writes. If set, the storage node
119 must rely on TCP's error correction to detect data corruption
120 in the data payload.
121
122 noasyncreaddir
123 Disable client's use its local cache to satisfy readdir
124 requests. (This does not change correctness; the client uses
125 cached metadata only when a lease or capability ensures it is
126 valid.)
127
128
129More Information
130================
131
132For more information on Ceph, see the home page at
133 http://ceph.newdream.net/
134
135The Linux kernel client source tree is available at
136 git://ceph.newdream.net/git/ceph-client.git
137 git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client.git
138
139and the source for the full system is at
140 git://ceph.newdream.net/git/ceph.git
diff --git a/Documentation/filesystems/tmpfs.txt b/Documentation/filesystems/tmpfs.txt
index 3015da0c6b2a..fe09a2cb1858 100644
--- a/Documentation/filesystems/tmpfs.txt
+++ b/Documentation/filesystems/tmpfs.txt
@@ -82,11 +82,13 @@ tmpfs has a mount option to set the NUMA memory allocation policy for
82all files in that instance (if CONFIG_NUMA is enabled) - which can be 82all files in that instance (if CONFIG_NUMA is enabled) - which can be
83adjusted on the fly via 'mount -o remount ...' 83adjusted on the fly via 'mount -o remount ...'
84 84
85mpol=default prefers to allocate memory from the local node 85mpol=default use the process allocation policy
86 (see set_mempolicy(2))
86mpol=prefer:Node prefers to allocate memory from the given Node 87mpol=prefer:Node prefers to allocate memory from the given Node
87mpol=bind:NodeList allocates memory only from nodes in NodeList 88mpol=bind:NodeList allocates memory only from nodes in NodeList
88mpol=interleave prefers to allocate from each node in turn 89mpol=interleave prefers to allocate from each node in turn
89mpol=interleave:NodeList allocates from each node of NodeList in turn 90mpol=interleave:NodeList allocates from each node of NodeList in turn
91mpol=local prefers to allocate memory from the local node
90 92
91NodeList format is a comma-separated list of decimal numbers and ranges, 93NodeList format is a comma-separated list of decimal numbers and ranges,
92a range being two hyphen-separated decimal numbers, the smallest and 94a range being two hyphen-separated decimal numbers, the smallest and
@@ -134,3 +136,5 @@ Author:
134 Christoph Rohland <cr@sap.com>, 1.12.01 136 Christoph Rohland <cr@sap.com>, 1.12.01
135Updated: 137Updated:
136 Hugh Dickins, 4 June 2007 138 Hugh Dickins, 4 June 2007
139Updated:
140 KOSAKI Motohiro, 16 Mar 2010
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 35c9b51d20ea..dd5806f4fcc4 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -291,6 +291,7 @@ Code Seq#(hex) Include File Comments
2910x92 00-0F drivers/usb/mon/mon_bin.c 2910x92 00-0F drivers/usb/mon/mon_bin.c
2920x93 60-7F linux/auto_fs.h 2920x93 60-7F linux/auto_fs.h
2930x94 all fs/btrfs/ioctl.h 2930x94 all fs/btrfs/ioctl.h
2940x97 00-7F fs/ceph/ioctl.h Ceph file system
2940x99 00-0F 537-Addinboard driver 2950x99 00-0F 537-Addinboard driver
295 <mailto:buk@buks.ipn.de> 296 <mailto:buk@buks.ipn.de>
2960xA0 all linux/sdp/sdp.h Industrial Device Project 2970xA0 all linux/sdp/sdp.h Industrial Device Project
diff --git a/Documentation/kobject.txt b/Documentation/kobject.txt
index bdb13817e1e9..3ab2472509cb 100644
--- a/Documentation/kobject.txt
+++ b/Documentation/kobject.txt
@@ -59,37 +59,56 @@ nice to have in other objects. The C language does not allow for the
59direct expression of inheritance, so other techniques - such as structure 59direct expression of inheritance, so other techniques - such as structure
60embedding - must be used. 60embedding - must be used.
61 61
62So, for example, the UIO code has a structure that defines the memory 62(As an aside, for those familiar with the kernel linked list implementation,
63region associated with a uio device: 63this is analogous as to how "list_head" structs are rarely useful on
64their own, but are invariably found embedded in the larger objects of
65interest.)
64 66
65struct uio_mem { 67So, for example, the UIO code in drivers/uio/uio.c has a structure that
68defines the memory region associated with a uio device:
69
70 struct uio_map {
66 struct kobject kobj; 71 struct kobject kobj;
67 unsigned long addr; 72 struct uio_mem *mem;
68 unsigned long size; 73 };
69 int memtype;
70 void __iomem *internal_addr;
71};
72 74
73If you have a struct uio_mem structure, finding its embedded kobject is 75If you have a struct uio_map structure, finding its embedded kobject is
74just a matter of using the kobj member. Code that works with kobjects will 76just a matter of using the kobj member. Code that works with kobjects will
75often have the opposite problem, however: given a struct kobject pointer, 77often have the opposite problem, however: given a struct kobject pointer,
76what is the pointer to the containing structure? You must avoid tricks 78what is the pointer to the containing structure? You must avoid tricks
77(such as assuming that the kobject is at the beginning of the structure) 79(such as assuming that the kobject is at the beginning of the structure)
78and, instead, use the container_of() macro, found in <linux/kernel.h>: 80and, instead, use the container_of() macro, found in <linux/kernel.h>:
79 81
80 container_of(pointer, type, member) 82 container_of(pointer, type, member)
83
84where:
85
86 * "pointer" is the pointer to the embedded kobject,
87 * "type" is the type of the containing structure, and
88 * "member" is the name of the structure field to which "pointer" points.
89
90The return value from container_of() is a pointer to the corresponding
91container type. So, for example, a pointer "kp" to a struct kobject
92embedded *within* a struct uio_map could be converted to a pointer to the
93*containing* uio_map structure with:
94
95 struct uio_map *u_map = container_of(kp, struct uio_map, kobj);
96
97For convenience, programmers often define a simple macro for "back-casting"
98kobject pointers to the containing type. Exactly this happens in the
99earlier drivers/uio/uio.c, as you can see here:
100
101 struct uio_map {
102 struct kobject kobj;
103 struct uio_mem *mem;
104 };
81 105
82where pointer is the pointer to the embedded kobject, type is the type of 106 #define to_map(map) container_of(map, struct uio_map, kobj)
83the containing structure, and member is the name of the structure field to
84which pointer points. The return value from container_of() is a pointer to
85the given type. So, for example, a pointer "kp" to a struct kobject
86embedded within a struct uio_mem could be converted to a pointer to the
87containing uio_mem structure with:
88 107
89 struct uio_mem *u_mem = container_of(kp, struct uio_mem, kobj); 108where the macro argument "map" is a pointer to the struct kobject in
109question. That macro is subsequently invoked with:
90 110
91Programmers often define a simple macro for "back-casting" kobject pointers 111 struct uio_map *map = to_map(kobj);
92to the containing type.
93 112
94 113
95Initialization of kobjects 114Initialization of kobjects
@@ -387,4 +406,5 @@ called, and the objects in the former circle release each other.
387Example code to copy from 406Example code to copy from
388 407
389For a more complete example of using ksets and kobjects properly, see the 408For a more complete example of using ksets and kobjects properly, see the
390sample/kobject/kset-example.c code. 409example programs samples/kobject/{kobject-example.c,kset-example.c},
410which will be built as loadable modules if you select CONFIG_SAMPLE_KOBJECT.
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt
index 7f5809eddee6..631ad2f1b229 100644
--- a/Documentation/memory-barriers.txt
+++ b/Documentation/memory-barriers.txt
@@ -3,6 +3,7 @@
3 ============================ 3 ============================
4 4
5By: David Howells <dhowells@redhat.com> 5By: David Howells <dhowells@redhat.com>
6 Paul E. McKenney <paulmck@linux.vnet.ibm.com>
6 7
7Contents: 8Contents:
8 9
@@ -60,6 +61,10 @@ Contents:
60 61
61 - And then there's the Alpha. 62 - And then there's the Alpha.
62 63
64 (*) Example uses.
65
66 - Circular buffers.
67
63 (*) References. 68 (*) References.
64 69
65 70
@@ -2226,6 +2231,21 @@ The Alpha defines the Linux kernel's memory barrier model.
2226See the subsection on "Cache Coherency" above. 2231See the subsection on "Cache Coherency" above.
2227 2232
2228 2233
2234============
2235EXAMPLE USES
2236============
2237
2238CIRCULAR BUFFERS
2239----------------
2240
2241Memory barriers can be used to implement circular buffering without the need
2242of a lock to serialise the producer with the consumer. See:
2243
2244 Documentation/circular-buffers.txt
2245
2246for details.
2247
2248
2229========== 2249==========
2230REFERENCES 2250REFERENCES
2231========== 2251==========
diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt
new file mode 100644
index 000000000000..7ee770b5ef5f
--- /dev/null
+++ b/Documentation/networking/stmmac.txt
@@ -0,0 +1,143 @@
1 STMicroelectronics 10/100/1000 Synopsys Ethernet driver
2
3Copyright (C) 2007-2010 STMicroelectronics Ltd
4Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
5
6This is the driver for the MAC 10/100/1000 on-chip Ethernet controllers
7(Synopsys IP blocks); it has been fully tested on STLinux platforms.
8
9Currently this network device driver is for all STM embedded MAC/GMAC
10(7xxx SoCs).
11
12DWC Ether MAC 10/100/1000 Universal version 3.41a and DWC Ether MAC 10/100
13Universal version 4.0 have been used for developing the first code
14implementation.
15
16Please, for more information also visit: www.stlinux.com
17
181) Kernel Configuration
19The kernel configuration option is STMMAC_ETH:
20 Device Drivers ---> Network device support ---> Ethernet (1000 Mbit) --->
21 STMicroelectronics 10/100/1000 Ethernet driver (STMMAC_ETH)
22
232) Driver parameters list:
24 debug: message level (0: no output, 16: all);
25 phyaddr: to manually provide the physical address to the PHY device;
26 dma_rxsize: DMA rx ring size;
27 dma_txsize: DMA tx ring size;
28 buf_sz: DMA buffer size;
29 tc: control the HW FIFO threshold;
30 tx_coe: Enable/Disable Tx Checksum Offload engine;
31 watchdog: transmit timeout (in milliseconds);
32 flow_ctrl: Flow control ability [on/off];
33 pause: Flow Control Pause Time;
34 tmrate: timer period (only if timer optimisation is configured).
35
363) Command line options
37Driver parameters can be also passed in command line by using:
38 stmmaceth=dma_rxsize:128,dma_txsize:512
39
404) Driver information and notes
41
424.1) Transmit process
43The xmit method is invoked when the kernel needs to transmit a packet; it sets
44the descriptors in the ring and informs the DMA engine that there is a packet
45ready to be transmitted.
46Once the controller has finished transmitting the packet, an interrupt is
47triggered; So the driver will be able to release the socket buffers.
48By default, the driver sets the NETIF_F_SG bit in the features field of the
49net_device structure enabling the scatter/gather feature.
50
514.2) Receive process
52When one or more packets are received, an interrupt happens. The interrupts
53are not queued so the driver has to scan all the descriptors in the ring during
54the receive process.
55This is based on NAPI so the interrupt handler signals only if there is work to be
56done, and it exits.
57Then the poll method will be scheduled at some future point.
58The incoming packets are stored, by the DMA, in a list of pre-allocated socket
59buffers in order to avoid the memcpy (Zero-copy).
60
614.3) Timer-Driver Interrupt
62Instead of having the device that asynchronously notifies the frame receptions, the
63driver configures a timer to generate an interrupt at regular intervals.
64Based on the granularity of the timer, the frames that are received by the device
65will experience different levels of latency. Some NICs have dedicated timer
66device to perform this task. STMMAC can use either the RTC device or the TMU
67channel 2 on STLinux platforms.
68The timers frequency can be passed to the driver as parameter; when change it,
69take care of both hardware capability and network stability/performance impact.
70Several performance tests on STM platforms showed this optimisation allows to spare
71the CPU while having the maximum throughput.
72
734.4) WOL
74Wake up on Lan feature through Magic Frame is only supported for the GMAC
75core.
76
774.5) DMA descriptors
78Driver handles both normal and enhanced descriptors. The latter has been only
79tested on DWC Ether MAC 10/100/1000 Universal version 3.41a.
80
814.6) Ethtool support
82Ethtool is supported. Driver statistics and internal errors can be taken using:
83ethtool -S ethX command. It is possible to dump registers etc.
84
854.7) Jumbo and Segmentation Offloading
86Jumbo frames are supported and tested for the GMAC.
87The GSO has been also added but it's performed in software.
88LRO is not supported.
89
904.8) Physical
91The driver is compatible with PAL to work with PHY and GPHY devices.
92
934.9) Platform information
94Several information came from the platform; please refer to the
95driver's Header file in include/linux directory.
96
97struct plat_stmmacenet_data {
98 int bus_id;
99 int pbl;
100 int has_gmac;
101 void (*fix_mac_speed)(void *priv, unsigned int speed);
102 void (*bus_setup)(unsigned long ioaddr);
103#ifdef CONFIG_STM_DRIVERS
104 struct stm_pad_config *pad_config;
105#endif
106 void *bsp_priv;
107};
108
109Where:
110- pbl (Programmable Burst Length) is maximum number of
111 beats to be transferred in one DMA transaction.
112 GMAC also enables the 4xPBL by default.
113- fix_mac_speed and bus_setup are used to configure internal target
114 registers (on STM platforms);
115- has_gmac: GMAC core is on board (get it at run-time in the next step);
116- bus_id: bus identifier.
117
118struct plat_stmmacphy_data {
119 int bus_id;
120 int phy_addr;
121 unsigned int phy_mask;
122 int interface;
123 int (*phy_reset)(void *priv);
124 void *priv;
125};
126
127Where:
128- bus_id: bus identifier;
129- phy_addr: physical address used for the attached phy device;
130 set it to -1 to get it at run-time;
131- interface: physical MII interface mode;
132- phy_reset: hook to reset HW function.
133
134TODO:
135- Continue to make the driver more generic and suitable for other Synopsys
136 Ethernet controllers used on other architectures (i.e. ARM).
137- 10G controllers are not supported.
138- MAC uses Normal descriptors and GMAC uses enhanced ones.
139 This is a limit that should be reviewed. MAC could want to
140 use the enhanced structure.
141- Checksumming: Rx/Tx csum is done in HW in case of GMAC only.
142- Review the timer optimisation code to use an embedded device that seems to be
143 available in new chip generations.
diff --git a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt
index 6e37be1eeb2d..4f8930263dd9 100644
--- a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt
+++ b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt
@@ -21,6 +21,15 @@ Required properties:
21- fsl,qe-num-snums: define how many serial number(SNUM) the QE can use for the 21- fsl,qe-num-snums: define how many serial number(SNUM) the QE can use for the
22 threads. 22 threads.
23 23
24Optional properties:
25- fsl,firmware-phandle:
26 Usage: required only if there is no fsl,qe-firmware child node
27 Value type: <phandle>
28 Definition: Points to a firmware node (see "QE Firmware Node" below)
29 that contains the firmware that should be uploaded for this QE.
30 The compatible property for the firmware node should say,
31 "fsl,qe-firmware".
32
24Recommended properties 33Recommended properties
25- brg-frequency : the internal clock source frequency for baud-rate 34- brg-frequency : the internal clock source frequency for baud-rate
26 generators in Hz. 35 generators in Hz.
@@ -59,3 +68,48 @@ Example:
59 reg = <0 c000>; 68 reg = <0 c000>;
60 }; 69 };
61 }; 70 };
71
72* QE Firmware Node
73
74This node defines a firmware binary that is embedded in the device tree, for
75the purpose of passing the firmware from bootloader to the kernel, or from
76the hypervisor to the guest.
77
78The firmware node itself contains the firmware binary contents, a compatible
79property, and any firmware-specific properties. The node should be placed
80inside a QE node that needs it. Doing so eliminates the need for a
81fsl,firmware-phandle property. Other QE nodes that need the same firmware
82should define an fsl,firmware-phandle property that points to the firmware node
83in the first QE node.
84
85The fsl,firmware property can be specified in the DTS (possibly using incbin)
86or can be inserted by the boot loader at boot time.
87
88Required properties:
89 - compatible
90 Usage: required
91 Value type: <string>
92 Definition: A standard property. Specify a string that indicates what
93 kind of firmware it is. For QE, this should be "fsl,qe-firmware".
94
95 - fsl,firmware
96 Usage: required
97 Value type: <prop-encoded-array>, encoded as an array of bytes
98 Definition: A standard property. This property contains the firmware
99 binary "blob".
100
101Example:
102 qe1@e0080000 {
103 compatible = "fsl,qe";
104 qe_firmware:qe-firmware {
105 compatible = "fsl,qe-firmware";
106 fsl,firmware = [0x70 0xcd 0x00 0x00 0x01 0x46 0x45 ...];
107 };
108 ...
109 };
110
111 qe2@e0090000 {
112 compatible = "fsl,qe";
113 fsl,firmware-phandle = <&qe_firmware>;
114 ...
115 };
diff --git a/Documentation/volatile-considered-harmful.txt b/Documentation/volatile-considered-harmful.txt
index 991c26a6ef64..db0cb228d64a 100644
--- a/Documentation/volatile-considered-harmful.txt
+++ b/Documentation/volatile-considered-harmful.txt
@@ -63,9 +63,9 @@ way to perform a busy wait is:
63 cpu_relax(); 63 cpu_relax();
64 64
65The cpu_relax() call can lower CPU power consumption or yield to a 65The cpu_relax() call can lower CPU power consumption or yield to a
66hyperthreaded twin processor; it also happens to serve as a memory barrier, 66hyperthreaded twin processor; it also happens to serve as a compiler
67so, once again, volatile is unnecessary. Of course, busy-waiting is 67barrier, so, once again, volatile is unnecessary. Of course, busy-
68generally an anti-social act to begin with. 68waiting is generally an anti-social act to begin with.
69 69
70There are still a few rare situations where volatile makes sense in the 70There are still a few rare situations where volatile makes sense in the
71kernel: 71kernel: