linux.git/arch/powerpc/include/asm/bitops.h, branch v4.12

powerpc: Add more PPC bit conversion macros

2017-04-06T09:58:53+00:00

Add 32 and 8 bit variants

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Michael Ellerman

powerpc/64s: POWER9 machine check handler

2017-03-10T05:32:08+00:00

Add POWER9 machine check handler. There are several new types of errors
added, so logging messages for those are also added.

This doesn't attempt to reuse any of the P7/8 defines or functions,
because that becomes too complex. The better option in future is to use
a table driven approach.

Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman

powerpc/64: Implement clear_bit_unlock_is_negative_byte()

2017-02-18T03:40:01+00:00

Commit b91e1302ad9b8 ("mm: optimize PageWaiters bit use for
unlock_page()") added a special bitop function to speed up
unlock_page(). Implement this for 64-bit powerpc.

This improves the unlock_page() core code from this:

	li	9,1
	lwsync
1:	ldarx	10,0,3,0
	andc	10,10,9
	stdcx.	10,0,3
	bne-	1b
	ori	2,2,0
	ld	9,0(3)
	andi.	10,9,0x80
	beqlr
	li	4,0
	b	wake_up_page_bit

To this:

	li	10,1
	lwsync
1:	ldarx	9,0,3,0
	andc	9,9,10
	stdcx.	9,0,3
	bne-	1b
	andi.	10,9,0x80
	beqlr
	li	4,0
	b	wake_up_page_bit

In a test of elapsed time for dd writing into 16GB of already-dirty
pagecache on a POWER8 with 4K pages, which has one unlock_page per 4kB
this patch reduced overhead by 1.1%:

    N           Min           Max        Median           Avg        Stddev
x  19         2.578         2.619         2.594         2.595         0.011
+  19         2.552         2.592         2.564         2.565         0.008
Difference at 95.0% confidence
	-0.030  +/- 0.006
	-1.142% +/- 0.243%

Signed-off-by: Nicholas Piggin 
[mpe: Made 64-bit only until I can test it properly on 32-bit]
Signed-off-by: Michael Ellerman

powerpc: Fix comment typos in arch/powerpc/include/asm/bitops.h

2014-11-12T05:31:46+00:00

In arch/powerpc/include/asm/bitops.h, the comments about bit numbers in
large (> 1 word) bitmaps have two typos:
- On ppc64 system, the LSB of the 4th word should be bit 192 rather than
  196, because if it's bit 196, bit 192-195 will be missing in the
  bitmap.
- On ppc32 system, the LSB of the second word should be bit 32 rather
  than 31, because bit 31 is already in the first word.

This patch fixes these typos.

Signed-off-by: Boqun Feng 
Signed-off-by: Michael Ellerman

powerpc: make __ffs return unsigned long

2014-11-09T22:59:27+00:00

I'm seeing a build warning in mm/nobootmem.c after removing
bootmem:

mm/nobootmem.c: In function '__free_pages_memory':
include/linux/kernel.h:713:17: warning: comparison of distinct pointer types lacks a cast [enabled by default]
  (void) (&_min1 == &_min2);  \
                 ^
mm/nobootmem.c:90:11: note: in expansion of macro 'min'
   order = min(MAX_ORDER - 1UL, __ffs(start));
           ^

The rest of the worlds seems to define __ffs as returning unsigned long,
so lets do that.

Signed-off-by: Anton Blanchard 
Tested-by: Emil Medve 
Signed-off-by: Michael Ellerman

arch,powerpc: Convert smp_mb__*()

2014-04-18T12:20:41+00:00

Powerpc allows reordering over its ll/sc implementation. Implement the
two new barriers as appropriate.

Signed-off-by: Peter Zijlstra 
Acked-by: Paul E. McKenney 
Link: http://lkml.kernel.org/n/tip-gg2ffgq32sjgy9b8lj6m3hsc@git.kernel.org
Cc: Benjamin Herrenschmidt 
Cc: Linus Torvalds 
Cc: Mahesh Salgaonkar 
Cc: Paul Gortmaker 
Cc: Paul Mackerras 
Cc: Will Deacon 
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Ingo Molnar

powerpc/book3s: Flush SLB/TLBs if we get SLB/TLB machine check errors on power7.

2013-12-05T05:04:39+00:00

If we get a machine check exception due to SLB or TLB errors, then flush
SLBs/TLBs and reload SLBs to recover. We do this in real mode before turning
on MMU. Otherwise we would run into nested machine checks.

If we get a machine check when we are in guest, then just flush the
SLBs and continue. This patch handles errors for power7. The next
patch will handle errors for power8

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Paul Mackerras 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Remove unused postfix parameter to DEFINE_BITOP()

2013-04-18T01:53:04+00:00

None of the users of DEFINE_BITOP pass a postfix, and as far as I can
tell none ever did, so drop it.

Signed-off-by: Michael Ellerman

powerpc: Remove unused BITOP_LE_SWIZZLE macro

2013-03-05T05:56:28+00:00

The BITOP_LE_SWIZZLE macro was used in the little-endian bitops functions
for powerpc.  But these functions were converted to generic bitops and
the BITOP_LE_SWIZZLE is not used anymore.

Signed-off-by: Akinobu Mita 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Benjamin Herrenschmidt

powerpc: Use asm-generic/bitops/le.h

2012-11-15T02:01:10+00:00

The only difference between powerpc and asm-generic le-bitops is
test_bit_le().  Usually all bitops require a long aligned bitmap.
But powerpc test_bit_le() can take an unaligned address.

There is no special callsite of test_bit_le() that needs unaligned
access in powerpc as far as I can see.  So convert to use
asm-generic/bitops/le.h for powerpc.

Signed-off-by: Akinobu Mita 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Benjamin Herrenschmidt