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  1. 11 12月, 2006 1 次提交
  3. 09 12月, 2006 1 次提交
    • D
      [PATCH] LOG2: Implement a general integer log2 facility in the kernel · f0d1b0b3
      由 David Howells 提交于 
      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: NDavid 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: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      f0d1b0b3
  5. 08 12月, 2006 23 次提交
  7. 06 12月, 2006 1 次提交
  9. 04 12月, 2006 2 次提交
    • A
      [ARM] 3972/1: AT91: Update board.h · c019d49b
      由 Andrew Victor 提交于 
      Replace the 'is_b' variable with 'slot_b' in at91_mmc_data.
Also add the new 'chipselect' variable for CF/PCMCIA and 'bus_width_16'
variable for NAND.

This (and previous patches) will unfortunately break the current MMC,
USB Gadget and PCMCIA drivers.  Updates and fixes for those drivers will
be submitted to the various subsystem maintainers.
Signed-off-by: NAndrew Victor <andrew@sanpeople.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      c019d49b
    • L
      [ARM] 3881/4: xscale: clean up cp0/cp1 handling · afe4b25e
      由 Lennert Buytenhek 提交于 
      XScale cores either have a DSP coprocessor (which contains a single
40 bit accumulator register), or an iWMMXt coprocessor (which contains
eight 64 bit registers.)

Because of the small amount of state in the DSP coprocessor, access to
the DSP coprocessor (CP0) is always enabled, and DSP context switching
is done unconditionally on every task switch.  Access to the iWMMXt
coprocessor (CP0/CP1) is enabled only when an iWMMXt instruction is
first issued, and iWMMXt context switching is done lazily.

CONFIG_IWMMXT is supposed to mean 'the cpu we will be running on will
have iWMMXt support', but boards are supposed to select this config
symbol by hand, and at least one pxa27x board doesn't get this right,
so on that board, proc-xscale.S will incorrectly assume that we have a
DSP coprocessor, enable CP0 on boot, and we will then only save the
first iWMMXt register (wR0) on context switches, which is Bad.

This patch redefines CONFIG_IWMMXT as 'the cpu we will be running on
might have iWMMXt support, and we will enable iWMMXt context switching
if it does.'  This means that with this patch, running a CONFIG_IWMMXT=n
kernel on an iWMMXt-capable CPU will no longer potentially corrupt iWMMXt
state over context switches, and running a CONFIG_IWMMXT=y kernel on a
non-iWMMXt capable CPU will still do DSP context save/restore.

These changes should make iWMMXt work on PXA3xx, and as a side effect,
enable proper acc0 save/restore on non-iWMMXt capable xsc3 cores such
as IOP13xx and IXP23xx (which will not have CONFIG_CPU_XSCALE defined),
as well as setting and using HWCAP_IWMMXT properly.
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Acked-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      afe4b25e
  11. 02 12月, 2006 9 次提交
  13. 01 12月, 2006 3 次提交