Commit graph

7 commits

Author SHA1 Message Date
David Howells
f0d1b0b30d [PATCH] LOG2: Implement a general integer log2 facility in the kernel
This facility provides three entry points:

	ilog2()		Log base 2 of unsigned long
	ilog2_u32()	Log base 2 of u32
	ilog2_u64()	Log base 2 of u64

These facilities can either be used inside functions on dynamic data:

	int do_something(long q)
	{
		...;
		y = ilog2(x)
		...;
	}

Or can be used to statically initialise global variables with constant values:

	unsigned n = ilog2(27);

When performing static initialisation, the compiler will report "error:
initializer element is not constant" if asked to take a log of zero or of
something not reducible to a constant.  They treat negative numbers as
unsigned.

When not dealing with a constant, they fall back to using fls() which permits
them to use arch-specific log calculation instructions - such as BSR on
x86/x86_64 or SCAN on FRV - if available.

[akpm@osdl.org: MMC fix]
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Wojtek Kaniewski <wojtekka@toxygen.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:51 -08:00
Ingo Molnar
0d7012a968 [PATCH] genirq: cleanup: turn ARCH_HAS_IRQ_PER_CPU into CONFIG_IRQ_PER_CPU
Cleanup: change ARCH_HAS_IRQ_PER_CPU into a Kconfig method.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 10:26:23 -07:00
Akinobu Mita
e9f26df172 [PATCH] bitops: cris: use generic bitops
- remove __{,test_and_}{set,clear,change}_bit() and test_bit()
- remove generic_fls()
- remove generic_fls64()
- remove generic_hweight{32,16,8}()
- remove find_{next,first}{,_zero}_bit()
- remove ext2_{set,clear,test,find_first_zero,find_next_zero}_bit()
- remove minix_{test,set,test_and_clear,test,find_first_zero}_bit()
- remove sched_find_first_bit()

Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Acked-by: Mikael Starvik <starvik@axis.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:57:12 -08:00
Matt Mackall
e585e47031 [PATCH] tiny: Make *[ug]id16 support optional
Configurable 16-bit UID and friends support

This allows turning off the legacy 16 bit UID interfaces on embedded platforms.

   text    data     bss     dec     hex filename
3330172  529036  190556 4049764  3dcb64 vmlinux-baseline
3328268  529040  190556 4047864  3dc3f8 vmlinux

From: Adrian Bunk <bunk@stusta.de>

    UID16 was accidentially disabled for !EMBEDDED.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 20:14:11 -08:00
Sam Ravnborg
d5950b4355 [NET]: add a top-level Networking menu to *config
Create a new top-level menu named "Networking" thus moving
net related options and protocol selection way from the drivers
menu and up on the top-level where they belong.

To implement this all architectures has to source "net/Kconfig" before
drivers/*/Kconfig in their Kconfig file. This change has been
implemented for all architectures.

Device drivers for ordinary NIC's are still to be found
in the Device Drivers section, but Bluetooth, IrDA and ax25
are located with their corresponding menu entries under the new
networking menu item.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-11 21:03:49 -07:00
Dave Hansen
3f22ab276b [PATCH] make each arch use mm/Kconfig
For all architectures, this just means that you'll see a "Memory Model"
choice in your architecture menu.  For those that implement DISCONTIGMEM,
you may eventually want to make your ARCH_DISCONTIGMEM_ENABLE a "def_bool
y" and make your users select DISCONTIGMEM right out of the new choice
menu.  The only disadvantage might be if you have some specific things that
you need in your help option to explain something about DISCONTIGMEM.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:02 -07:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00