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authorLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 21:24:40 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 21:24:40 +0200
commit7540081c6b16dc941895bca840749cabfd0d3b48 (patch)
tree9e6b2270d700bf99489b570aa2b4c2c0b6cd0ead
parentMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ger... (diff)
parentRemove __DECLARE_SEMAPHORE_GENERIC (diff)
downloadlinux-7540081c6b16dc941895bca840749cabfd0d3b48.tar.xz
linux-7540081c6b16dc941895bca840749cabfd0d3b48.zip
Merge branch 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc
* 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc: Remove __DECLARE_SEMAPHORE_GENERIC Remove asm/semaphore.h Remove use of asm/semaphore.h Add missing semaphore.h includes Remove mention of semaphores from kernel-locking
-rw-r--r--Documentation/DocBook/kernel-locking.tmpl57
-rw-r--r--Documentation/feature-removal-schedule.txt8
-rw-r--r--arch/arm/mach-ns9xxx/clock.c2
-rw-r--r--drivers/input/keyboard/hil_kbd.c1
-rw-r--r--drivers/input/misc/hp_sdc_rtc.c1
-rw-r--r--drivers/input/serio/hp_sdc.c1
-rw-r--r--include/asm-alpha/semaphore.h1
-rw-r--r--include/asm-arm/semaphore.h1
-rw-r--r--include/asm-avr32/semaphore.h1
-rw-r--r--include/asm-blackfin/semaphore.h1
-rw-r--r--include/asm-cris/semaphore.h1
-rw-r--r--include/asm-frv/semaphore.h1
-rw-r--r--include/asm-h8300/semaphore.h1
-rw-r--r--include/asm-ia64/semaphore.h1
-rw-r--r--include/asm-m32r/semaphore.h1
-rw-r--r--include/asm-m68k/semaphore.h1
-rw-r--r--include/asm-m68knommu/semaphore.h1
-rw-r--r--include/asm-mips/semaphore.h1
-rw-r--r--include/asm-mn10300/semaphore.h1
-rw-r--r--include/asm-parisc/semaphore.h1
-rw-r--r--include/asm-powerpc/semaphore.h1
-rw-r--r--include/asm-s390/semaphore.h1
-rw-r--r--include/asm-sh/semaphore.h1
-rw-r--r--include/asm-sparc/semaphore.h1
-rw-r--r--include/asm-sparc64/semaphore.h1
-rw-r--r--include/asm-um/semaphore.h1
-rw-r--r--include/asm-x86/semaphore.h1
-rw-r--r--include/asm-xtensa/semaphore.h1
-rw-r--r--include/linux/semaphore.h6
29 files changed, 30 insertions, 68 deletions
diff --git a/Documentation/DocBook/kernel-locking.tmpl b/Documentation/DocBook/kernel-locking.tmpl
index 2510763295d0..084f6ad7b7a0 100644
--- a/Documentation/DocBook/kernel-locking.tmpl
+++ b/Documentation/DocBook/kernel-locking.tmpl
@@ -219,10 +219,10 @@
</para>
<sect1 id="lock-intro">
- <title>Three Main Types of Kernel Locks: Spinlocks, Mutexes and Semaphores</title>
+ <title>Two Main Types of Kernel Locks: Spinlocks and Mutexes</title>
<para>
- There are three main types of kernel locks. The fundamental type
+ There are two main types of kernel locks. The fundamental type
is the spinlock
(<filename class="headerfile">include/asm/spinlock.h</filename>),
which is a very simple single-holder lock: if you can't get the
@@ -240,14 +240,6 @@
use a spinlock instead.
</para>
<para>
- The third type is a semaphore
- (<filename class="headerfile">include/linux/semaphore.h</filename>): it
- can have more than one holder at any time (the number decided at
- initialization time), although it is most commonly used as a
- single-holder lock (a mutex). If you can't get a semaphore, your
- task will be suspended and later on woken up - just like for mutexes.
- </para>
- <para>
Neither type of lock is recursive: see
<xref linkend="deadlock"/>.
</para>
@@ -278,7 +270,7 @@
</para>
<para>
- Semaphores still exist, because they are required for
+ Mutexes still exist, because they are required for
synchronization between <firstterm linkend="gloss-usercontext">user
contexts</firstterm>, as we will see below.
</para>
@@ -289,18 +281,17 @@
<para>
If you have a data structure which is only ever accessed from
- user context, then you can use a simple semaphore
- (<filename>linux/linux/semaphore.h</filename>) to protect it. This
- is the most trivial case: you initialize the semaphore to the number
- of resources available (usually 1), and call
- <function>down_interruptible()</function> to grab the semaphore, and
- <function>up()</function> to release it. There is also a
- <function>down()</function>, which should be avoided, because it
+ user context, then you can use a simple mutex
+ (<filename>include/linux/mutex.h</filename>) to protect it. This
+ is the most trivial case: you initialize the mutex. Then you can
+ call <function>mutex_lock_interruptible()</function> to grab the mutex,
+ and <function>mutex_unlock()</function> to release it. There is also a
+ <function>mutex_lock()</function>, which should be avoided, because it
will not return if a signal is received.
</para>
<para>
- Example: <filename>linux/net/core/netfilter.c</filename> allows
+ Example: <filename>net/netfilter/nf_sockopt.c</filename> allows
registration of new <function>setsockopt()</function> and
<function>getsockopt()</function> calls, with
<function>nf_register_sockopt()</function>. Registration and
@@ -515,7 +506,7 @@
<listitem>
<para>
If you are in a process context (any syscall) and want to
- lock other process out, use a semaphore. You can take a semaphore
+ lock other process out, use a mutex. You can take a mutex
and sleep (<function>copy_from_user*(</function> or
<function>kmalloc(x,GFP_KERNEL)</function>).
</para>
@@ -662,7 +653,7 @@
<entry>SLBH</entry>
<entry>SLBH</entry>
<entry>SLBH</entry>
-<entry>DI</entry>
+<entry>MLI</entry>
<entry>None</entry>
</row>
@@ -692,8 +683,8 @@
<entry>spin_lock_bh</entry>
</row>
<row>
-<entry>DI</entry>
-<entry>down_interruptible</entry>
+<entry>MLI</entry>
+<entry>mutex_lock_interruptible</entry>
</row>
</tbody>
@@ -1310,7 +1301,7 @@ as Alan Cox says, <quote>Lock data, not code</quote>.
<para>
There is a coding bug where a piece of code tries to grab a
spinlock twice: it will spin forever, waiting for the lock to
- be released (spinlocks, rwlocks and semaphores are not
+ be released (spinlocks, rwlocks and mutexes are not
recursive in Linux). This is trivial to diagnose: not a
stay-up-five-nights-talk-to-fluffy-code-bunnies kind of
problem.
@@ -1335,7 +1326,7 @@ as Alan Cox says, <quote>Lock data, not code</quote>.
<para>
This complete lockup is easy to diagnose: on SMP boxes the
- watchdog timer or compiling with <symbol>DEBUG_SPINLOCKS</symbol> set
+ watchdog timer or compiling with <symbol>DEBUG_SPINLOCK</symbol> set
(<filename>include/linux/spinlock.h</filename>) will show this up
immediately when it happens.
</para>
@@ -1558,7 +1549,7 @@ the amount of locking which needs to be done.
<title>Read/Write Lock Variants</title>
<para>
- Both spinlocks and semaphores have read/write variants:
+ Both spinlocks and mutexes have read/write variants:
<type>rwlock_t</type> and <structname>struct rw_semaphore</structname>.
These divide users into two classes: the readers and the writers. If
you are only reading the data, you can get a read lock, but to write to
@@ -1681,7 +1672,7 @@ the amount of locking which needs to be done.
#include &lt;linux/slab.h&gt;
#include &lt;linux/string.h&gt;
+#include &lt;linux/rcupdate.h&gt;
- #include &lt;linux/semaphore.h&gt;
+ #include &lt;linux/mutex.h&gt;
#include &lt;asm/errno.h&gt;
struct object
@@ -1913,7 +1904,7 @@ machines due to caching.
</listitem>
<listitem>
<para>
- <function> put_user()</function>
+ <function>put_user()</function>
</para>
</listitem>
</itemizedlist>
@@ -1927,13 +1918,13 @@ machines due to caching.
<listitem>
<para>
- <function>down_interruptible()</function> and
- <function>down()</function>
+ <function>mutex_lock_interruptible()</function> and
+ <function>mutex_lock()</function>
</para>
<para>
- There is a <function>down_trylock()</function> which can be
+ There is a <function>mutex_trylock()</function> which can be
used inside interrupt context, as it will not sleep.
- <function>up()</function> will also never sleep.
+ <function>mutex_unlock()</function> will also never sleep.
</para>
</listitem>
</itemizedlist>
@@ -2023,7 +2014,7 @@ machines due to caching.
<para>
Prior to 2.5, or when <symbol>CONFIG_PREEMPT</symbol> is
unset, processes in user context inside the kernel would not
- preempt each other (ie. you had that CPU until you have it up,
+ preempt each other (ie. you had that CPU until you gave it up,
except for interrupts). With the addition of
<symbol>CONFIG_PREEMPT</symbol> in 2.5.4, this changed: when
in user context, higher priority tasks can "cut in": spinlocks
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 9f73587219e8..09c4a1efb8e3 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -300,14 +300,6 @@ Who: ocfs2-devel@oss.oracle.com
---------------------------
-What: asm/semaphore.h
-When: 2.6.26
-Why: Implementation became generic; users should now include
- linux/semaphore.h instead.
-Who: Matthew Wilcox <willy@linux.intel.com>
-
----------------------------
-
What: SCTP_GET_PEER_ADDRS_NUM_OLD, SCTP_GET_PEER_ADDRS_OLD,
SCTP_GET_LOCAL_ADDRS_NUM_OLD, SCTP_GET_LOCAL_ADDRS_OLD
When: June 2009
diff --git a/arch/arm/mach-ns9xxx/clock.c b/arch/arm/mach-ns9xxx/clock.c
index f8639161068f..44ed20d4a388 100644
--- a/arch/arm/mach-ns9xxx/clock.c
+++ b/arch/arm/mach-ns9xxx/clock.c
@@ -14,8 +14,8 @@
#include <linux/clk.h>
#include <linux/string.h>
#include <linux/platform_device.h>
+#include <linux/semaphore.h>
-#include <asm/semaphore.h>
#include "clock.h"
static LIST_HEAD(clocks);
diff --git a/drivers/input/keyboard/hil_kbd.c b/drivers/input/keyboard/hil_kbd.c
index adbf29f0169d..71c1971abf80 100644
--- a/drivers/input/keyboard/hil_kbd.c
+++ b/drivers/input/keyboard/hil_kbd.c
@@ -37,6 +37,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
+#include <linux/semaphore.h>
#include <linux/slab.h>
#include <linux/pci_ids.h>
diff --git a/drivers/input/misc/hp_sdc_rtc.c b/drivers/input/misc/hp_sdc_rtc.c
index 49d8abfe38fe..daa9d4220331 100644
--- a/drivers/input/misc/hp_sdc_rtc.c
+++ b/drivers/input/misc/hp_sdc_rtc.c
@@ -44,6 +44,7 @@
#include <linux/proc_fs.h>
#include <linux/poll.h>
#include <linux/rtc.h>
+#include <linux/semaphore.h>
MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
MODULE_DESCRIPTION("HP i8042 SDC + MSM-58321 RTC Driver");
diff --git a/drivers/input/serio/hp_sdc.c b/drivers/input/serio/hp_sdc.c
index 7b233a492ad5..aad664d5259f 100644
--- a/drivers/input/serio/hp_sdc.c
+++ b/drivers/input/serio/hp_sdc.c
@@ -67,6 +67,7 @@
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/time.h>
+#include <linux/semaphore.h>
#include <linux/slab.h>
#include <linux/hil.h>
#include <linux/semaphore.h>
diff --git a/include/asm-alpha/semaphore.h b/include/asm-alpha/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-alpha/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-arm/semaphore.h b/include/asm-arm/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-arm/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-avr32/semaphore.h b/include/asm-avr32/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-avr32/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-blackfin/semaphore.h b/include/asm-blackfin/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-blackfin/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-cris/semaphore.h b/include/asm-cris/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-cris/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-frv/semaphore.h b/include/asm-frv/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-frv/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-h8300/semaphore.h b/include/asm-h8300/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-h8300/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-ia64/semaphore.h b/include/asm-ia64/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-ia64/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-m32r/semaphore.h b/include/asm-m32r/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-m32r/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-m68k/semaphore.h b/include/asm-m68k/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-m68k/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-m68knommu/semaphore.h b/include/asm-m68knommu/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-m68knommu/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-mips/semaphore.h b/include/asm-mips/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-mips/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-mn10300/semaphore.h b/include/asm-mn10300/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-mn10300/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-parisc/semaphore.h b/include/asm-parisc/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-parisc/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-powerpc/semaphore.h b/include/asm-powerpc/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-powerpc/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-s390/semaphore.h b/include/asm-s390/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-s390/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-sh/semaphore.h b/include/asm-sh/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-sh/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-sparc/semaphore.h b/include/asm-sparc/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-sparc/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-sparc64/semaphore.h b/include/asm-sparc64/semaphore.h
deleted file mode 100644
index 39362afde5fe..000000000000
--- a/include/asm-sparc64/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <asm-sparc/semaphore.h>
diff --git a/include/asm-um/semaphore.h b/include/asm-um/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-um/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-x86/semaphore.h b/include/asm-x86/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-x86/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/asm-xtensa/semaphore.h b/include/asm-xtensa/semaphore.h
deleted file mode 100644
index d9b2034ed1d2..000000000000
--- a/include/asm-xtensa/semaphore.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <linux/semaphore.h>
diff --git a/include/linux/semaphore.h b/include/linux/semaphore.h
index 9cae64b00d6b..7415839ac890 100644
--- a/include/linux/semaphore.h
+++ b/include/linux/semaphore.h
@@ -26,10 +26,8 @@ struct semaphore {
.wait_list = LIST_HEAD_INIT((name).wait_list), \
}
-#define __DECLARE_SEMAPHORE_GENERIC(name, count) \
- struct semaphore name = __SEMAPHORE_INITIALIZER(name, count)
-
-#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name, 1)
+#define DECLARE_MUTEX(name) \
+ struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1)
static inline void sema_init(struct semaphore *sem, int val)
{