linux-toradex.git/lib/Makefile, branch v2.6.21-rc2

[PATCH] sort the devres mess out

2007-02-11T19:18:07+00:00

* Split the implementation-agnostic stuff in separate files.
* Make sure that targets using non-default request_irq() pull
  kernel/irq/devres.o
* Introduce new symbols (HAS_IOPORT and HAS_IOMEM) defaulting to positive;
  allow architectures to turn them off (we needed these symbols anyway for
  dependencies of quite a few drivers).
* protect the ioport-related parts of lib/devres.o with CONFIG_HAS_IOPORT.

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

[PATCH] Consolidate bust_spinlocks()

2007-02-11T18:51:34+00:00

Part of long forgotten patch
http://groups.google.com/group/fa.linux.kernel/msg/e98e941ce1cf29f6?dmode=source
Since then, m32r grabbed two copies.

Leave s390 copy because of important absence of CONFIG_VT, but remove
references to non-existent timerlist_lock.  ia64 also loses timerlist_lock.

Signed-off-by: Alexey Dobriyan 
Acked-by: Martin Schwidefsky 
Cc: Andi Kleen 
Cc: "Luck, Tony" 
Cc: Hirokazu Takata 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

iomap: iomap should be in obj-y not in lib-y

2007-02-09T22:39:37+00:00

devres change moved iomap.o from obj-$(CONFIG_GENERIC_IOMAP) to lib-y
making it not linked if no in-kernel driver uses it.  Fix it.

Signed-off-by: Tejun Heo 
Signed-off-by: Jeff Garzik

devres: device resource management

2007-02-09T22:39:36+00:00

Implement device resource management, in short, devres.  A device
driver can allocate arbirary size of devres data which is associated
with a release function.  On driver detach, release function is
invoked on the devres data, then, devres data is freed.

devreses are typed by associated release functions.  Some devreses are
better represented by single instance of the type while others need
multiple instances sharing the same release function.  Both usages are
supported.

devreses can be grouped using devres group such that a device driver
can easily release acquired resources halfway through initialization
or selectively release resources (e.g. resources for port 1 out of 4
ports).

This patch adds devres core including documentation and the following
managed interfaces.

* alloc/free	: devm_kzalloc(), devm_kzfree()
* IO region	: devm_request_region(), devm_release_region()
* IRQ		: devm_request_irq(), devm_free_irq()
* DMA		: dmam_alloc_coherent(), dmam_free_coherent(),
		  dmam_declare_coherent_memory(), dmam_pool_create(),
		  dmam_pool_destroy()
* PCI		: pcim_enable_device(), pcim_pin_device(), pci_is_managed()
* iomap		: devm_ioport_map(), devm_ioport_unmap(), devm_ioremap(),
		  devm_ioremap_nocache(), devm_iounmap(), pcim_iomap_table(),
		  pcim_iomap(), pcim_iounmap()

Signed-off-by: Tejun Heo 
Signed-off-by: Jeff Garzik

[PATCH] uml problems with linux/io.h

2006-12-13T17:05:52+00:00

Remove useless includes of linux/io.h, don't even try to build iomap_copy
on uml (it doesn't have readb() et.al., so...)

Signed-off-by: Al Viro 
Acked-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] SLAB: use a multiply instead of a divide in obj_to_index()

2006-12-13T17:05:49+00:00

When some objects are allocated by one CPU but freed by another CPU we can
consume lot of cycles doing divides in obj_to_index().

(Typical load on a dual processor machine where network interrupts are
handled by one particular CPU (allocating skbufs), and the other CPU is
running the application (consuming and freeing skbufs))

Here on one production server (dual-core AMD Opteron 285), I noticed this
divide took 1.20 % of CPU_CLK_UNHALTED events in kernel.  But Opteron are
quite modern cpus and the divide is much more expensive on oldest
architectures :

On a 200 MHz sparcv9 machine, the division takes 64 cycles instead of 1
cycle for a multiply.

Doing some math, we can use a reciprocal multiplication instead of a divide.

If we want to compute V = (A / B)  (A and B being u32 quantities)
we can instead use :

V = ((u64)A * RECIPROCAL(B)) >> 32 ;

where RECIPROCAL(B) is precalculated to ((1LL << 32) + (B - 1)) / B

Note :

I wrote pure C code for clarity. gcc output for i386 is not optimal but
acceptable :

mull   0x14(%ebx)
mov    %edx,%eax // part of the >> 32
xor     %edx,%edx // useless
mov    %eax,(%esp) // could be avoided
mov    %edx,0x4(%esp) // useless
mov    (%esp),%ebx

[akpm@osdl.org: small cleanups]
Signed-off-by: Eric Dumazet 
Cc: Christoph Lameter 
Cc: David Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] fault-injection capabilities infrastructure

2006-12-08T16:29:02+00:00

This patch provides base functions implement to fault-injection
capabilities.

- The function should_fail() is taken from failmalloc-1.0
  (http://www.nongnu.org/failmalloc/)

[akpm@osdl.org: cleanups, comments, add __init]
Cc: 
Signed-off-by: Akinobu Mita 
Signed-off-by: Don Mullis 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] bit reverse library

2006-12-08T16:28:39+00:00

This patch provides two bit reverse functions and bit reverse table.

- reverse the order of bits in a u32 value

	u8 bitrev8(u8 x);

- reverse the order of bits in a u32 value

	u32 bitrev32(u32 x);

- byte reverse table

	const u8 byte_rev_table[256];

Signed-off-by: Akinobu Mita 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Generic BUG implementation

2006-12-08T16:28:39+00:00

This patch adds common handling for kernel BUGs, for use by architectures as
they wish.  The code is derived from arch/powerpc.

The advantages of having common BUG handling are:
 - consistent BUG reporting across architectures
 - shared implementation of out-of-line file/line data
 - implement CONFIG_DEBUG_BUGVERBOSE consistently

This means that in inline impact of BUG is just the illegal instruction
itself, which is an improvement for i386 and x86-64.

A BUG is represented in the instruction stream as an illegal instruction,
which has file/line information associated with it.  This extra information is
stored in the __bug_table section in the ELF file.

When the kernel gets an illegal instruction, it first confirms it might
possibly be from a BUG (ie, in kernel mode, the right illegal instruction).
It then calls report_bug().  This searches __bug_table for a matching
instruction pointer, and if found, prints the corresponding file/line
information.  If report_bug() determines that it wasn't a BUG which caused the
trap, it returns BUG_TRAP_TYPE_NONE.

Some architectures (powerpc) implement WARN using the same mechanism; if the
illegal instruction was the result of a WARN, then report_bug(Q) returns
CONFIG_DEBUG_BUGVERBOSE; otherwise it returns BUG_TRAP_TYPE_BUG.

lib/bug.c keeps a list of loaded modules which can be searched for __bug_table
entries.  The architecture must call
module_bug_finalize()/module_bug_cleanup() from its corresponding
module_finalize/cleanup functions.

Unsetting CONFIG_DEBUG_BUGVERBOSE will reduce the kernel size by some amount.
At the very least, filename and line information will not be recorded for each
but, but architectures may decide to store no extra information per BUG at
all.

Unfortunately, gcc doesn't have a general way to mark an asm() as noreturn, so
architectures will generally have to include an infinite loop (or similar) in
the BUG code, so that gcc knows execution won't continue beyond that point.
gcc does have a __builtin_trap() operator which may be useful to achieve the
same effect, unfortunately it cannot be used to actually implement the BUG
itself, because there's no way to get the instruction's address for use in
generating the __bug_table entry.

[randy.dunlap@oracle.com: Handle BUG=n, GENERIC_BUG=n to prevent build errors]
[bunk@stusta.de: include/linux/bug.h must always #include 
Cc: Andi Kleen 
Cc: Hugh Dickens 
Cc: Michael Ellerman 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
Cc: Rusty Russell 
Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] lib functions: always build hweight for loadable modules

2006-12-07T16:39:42+00:00

Always build hweight8/16/32/64() functions into the kernel so that loadable
modules may use them.

I didn't remove GENERIC_HWEIGHT since ALPHA_EV67, ia64, and some variants
of UltraSparc(64) provide their own hweight functions.

Fixes config/build problems with NTFS=m and JOYSTICK_ANALOG=m.

  Kernel: arch/x86_64/boot/bzImage is ready  (#19)
    Building modules, stage 2.
    MODPOST 94 modules
  WARNING: "hweight32" [fs/ntfs/ntfs.ko] undefined!
  WARNING: "hweight16" [drivers/input/joystick/analog.ko] undefined!
  WARNING: "hweight8" [drivers/input/joystick/analog.ko] undefined!
  make[1]: *** [__modpost] Error 1
  make: *** [modules] Error 2

Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds