<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/powerpc/lib, branch v2.6.28</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>powerpc: Fix corruption error in rh_alloc_fixed()</title>
<updated>2008-12-17T16:06:14+00:00</updated>
<author>
<name>Guillaume Knispel</name>
<email>gknispel@proformatique.com</email>
</author>
<published>2008-12-09T14:28:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=af4d3643864ee5fcba0c97d77a424fa0b0346f8e'/>
<id>af4d3643864ee5fcba0c97d77a424fa0b0346f8e</id>
<content type='text'>
There is an error in rh_alloc_fixed() of the Remote Heap code:
If there is at least one free block blk won't be NULL at the end of the
search loop, so -ENOMEM won't be returned and the else branch of
"if (bs == s || be == e)" will be taken, corrupting the management
structures.

Signed-off-by: Guillaume Knispel &lt;gknispel@proformatique.com&gt;
Acked-by: Timur Tabi &lt;timur@freescale.com&gt;
Signed-off-by: Kumar Gala &lt;galak@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is an error in rh_alloc_fixed() of the Remote Heap code:
If there is at least one free block blk won't be NULL at the end of the
search loop, so -ENOMEM won't be returned and the else branch of
"if (bs == s || be == e)" will be taken, corrupting the management
structures.

Signed-off-by: Guillaume Knispel &lt;gknispel@proformatique.com&gt;
Acked-by: Timur Tabi &lt;timur@freescale.com&gt;
Signed-off-by: Kumar Gala &lt;galak@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Fix DMA offset for non-coherent DMA</title>
<updated>2008-10-13T23:35:26+00:00</updated>
<author>
<name>Benjamin Herrenschmidt</name>
<email>benh@kernel.crashing.org</email>
</author>
<published>2008-10-09T17:06:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8aa2659009714cf5f9ffe7f3e16ccfa8ff0e0d61'/>
<id>8aa2659009714cf5f9ffe7f3e16ccfa8ff0e0d61</id>
<content type='text'>
After Becky's work we can almost have different DMA offsets
between on-chip devices and PCI. Almost because there's a
problem with the non-coherent DMA code that basically ignores
the programmed offset to use the global one for everything.
This fixes it.

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
After Becky's work we can almost have different DMA offsets
between on-chip devices and PCI. Almost because there's a
problem with the non-coherent DMA code that basically ignores
the programmed offset to use the global one for everything.
This fixes it.

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: New copy_4K_page()</title>
<updated>2008-09-15T18:07:42+00:00</updated>
<author>
<name>Mark Nelson</name>
<email>markn@au1.ibm.com</email>
</author>
<published>2008-08-22T04:39:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=57dda6ef5bd5b9e60410477ad29e654097e2cca1'/>
<id>57dda6ef5bd5b9e60410477ad29e654097e2cca1</id>
<content type='text'>
This new copy_4K_page() function was originally tuned for the best
performance on the Cell processor, but after testing on more 64bit
powerpc chips it was found that with a small modification it either
matched the performance offered by the current mainline version or
bettered it by a small amount.

It was found that on a Cell-based QS22 blade the amount of system
time measured when compiling a 2.6.26 pseries_defconfig decreased
by 4%. Using the same test, a 4-way 970MP machine saw a decrease of
2% in system time. No noticeable change was seen on Power4, Power5
or Power6.

The 4096 byte page is copied in thirty-two 128 byte strides. An
initial setup loop executes dcbt instructions for the whole source
page and dcbz instructions for the whole destination page. To do
this, the cache line size is retrieved from ppc64_caches.

A new CPU feature bit, CPU_FTR_CP_USE_DCBTZ, (introduced in the
previous patch) is used to make the modification to this new copy
routine - on Power4, 970 and Cell the feature bit is set so the
setup loop is executed, but on all other 64bit chips the setup
loop is nop'ed out.

Signed-off-by: Mark Nelson &lt;markn@au1.ibm.com&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This new copy_4K_page() function was originally tuned for the best
performance on the Cell processor, but after testing on more 64bit
powerpc chips it was found that with a small modification it either
matched the performance offered by the current mainline version or
bettered it by a small amount.

It was found that on a Cell-based QS22 blade the amount of system
time measured when compiling a 2.6.26 pseries_defconfig decreased
by 4%. Using the same test, a 4-way 970MP machine saw a decrease of
2% in system time. No noticeable change was seen on Power4, Power5
or Power6.

The 4096 byte page is copied in thirty-two 128 byte strides. An
initial setup loop executes dcbt instructions for the whole source
page and dcbz instructions for the whole destination page. To do
this, the cache line size is retrieved from ppc64_caches.

A new CPU feature bit, CPU_FTR_CP_USE_DCBTZ, (introduced in the
previous patch) is used to make the modification to this new copy
routine - on Power4, 970 and Cell the feature bit is set so the
setup loop is executed, but on all other 64bit chips the setup
loop is nop'ed out.

Signed-off-by: Mark Nelson &lt;markn@au1.ibm.com&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Remove use of CONFIG_PPC_MERGE</title>
<updated>2008-08-04T03:18:17+00:00</updated>
<author>
<name>Kumar Gala</name>
<email>galak@kernel.crashing.org</email>
</author>
<published>2008-08-01T16:44:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9c4cb82515130c62224e23fdf7c13c8f6c59c614'/>
<id>9c4cb82515130c62224e23fdf7c13c8f6c59c614</id>
<content type='text'>
Now that arch/ppc is gone and CONFIG_PPC_MERGE is always set, remove
the dead code associated with !CONFIG_PPC_MERGE from arch/powerpc
and include/asm-powerpc.

Signed-off-by: Kumar Gala &lt;galak@kernel.crashing.org&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now that arch/ppc is gone and CONFIG_PPC_MERGE is always set, remove
the dead code associated with !CONFIG_PPC_MERGE from arch/powerpc
and include/asm-powerpc.

Signed-off-by: Kumar Gala &lt;galak@kernel.crashing.org&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures</title>
<updated>2008-07-24T17:47:21+00:00</updated>
<author>
<name>Andrea Righi</name>
<email>righi.andrea@gmail.com</email>
</author>
<published>2008-07-24T04:28:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=27ac792ca0b0a1e7e65f20342260650516c95864'/>
<id>27ac792ca0b0a1e7e65f20342260650516c95864</id>
<content type='text'>
On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit
boundary. For example:

	u64 val = PAGE_ALIGN(size);

always returns a value &lt; 4GB even if size is greater than 4GB.

The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for
example):

#define PAGE_SHIFT      12
#define PAGE_SIZE       (_AC(1,UL) &lt;&lt; PAGE_SHIFT)
#define PAGE_MASK       (~(PAGE_SIZE-1))
...
#define PAGE_ALIGN(addr)       (((addr)+PAGE_SIZE-1)&amp;PAGE_MASK)

The "~" is performed on a 32-bit value, so everything in "and" with
PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary.
Using the ALIGN() macro seems to be the right way, because it uses
typeof(addr) for the mask.

Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in
include/linux/mm.h.

See also lkml discussion: http://lkml.org/lkml/2008/6/11/237

[akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c]
[akpm@linux-foundation.org: fix v850]
[akpm@linux-foundation.org: fix powerpc]
[akpm@linux-foundation.org: fix arm]
[akpm@linux-foundation.org: fix mips]
[akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c]
[akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c]
[akpm@linux-foundation.org: fix powerpc]
Signed-off-by: Andrea Righi &lt;righi.andrea@gmail.com&gt;
Cc: &lt;linux-arch@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit
boundary. For example:

	u64 val = PAGE_ALIGN(size);

always returns a value &lt; 4GB even if size is greater than 4GB.

The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for
example):

#define PAGE_SHIFT      12
#define PAGE_SIZE       (_AC(1,UL) &lt;&lt; PAGE_SHIFT)
#define PAGE_MASK       (~(PAGE_SIZE-1))
...
#define PAGE_ALIGN(addr)       (((addr)+PAGE_SIZE-1)&amp;PAGE_MASK)

The "~" is performed on a 32-bit value, so everything in "and" with
PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary.
Using the ALIGN() macro seems to be the right way, because it uses
typeof(addr) for the mask.

Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in
include/linux/mm.h.

See also lkml discussion: http://lkml.org/lkml/2008/6/11/237

[akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c]
[akpm@linux-foundation.org: fix v850]
[akpm@linux-foundation.org: fix powerpc]
[akpm@linux-foundation.org: fix arm]
[akpm@linux-foundation.org: fix mips]
[akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c]
[akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c]
[akpm@linux-foundation.org: fix powerpc]
Signed-off-by: Andrea Righi &lt;righi.andrea@gmail.com&gt;
Cc: &lt;linux-arch@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Use PPC_LONG and PPC_LONG_ALIGN in lib/string.S</title>
<updated>2008-07-22T00:39:35+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>michael@ellerman.id.au</email>
</author>
<published>2008-07-17T07:17:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=76bfdcf71c421154b69470e1ce346c8cf4ee1230'/>
<id>76bfdcf71c421154b69470e1ce346c8cf4ee1230</id>
<content type='text'>
Replace ifdef clutter with the PPC_LONG and PPC_LONG_ALIGN macros
for readability.

No change to the generated code.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Replace ifdef clutter with the PPC_LONG and PPC_LONG_ALIGN macros
for readability.

No change to the generated code.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Use WARN_ON(1) instead of __WARN()</title>
<updated>2008-07-22T00:39:34+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>michael@ellerman.id.au</email>
</author>
<published>2008-07-17T04:46:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1856c020402f602b2bd26bcc9b77250304565b7e'/>
<id>1856c020402f602b2bd26bcc9b77250304565b7e</id>
<content type='text'>
__WARN() is not defined for all configs, use WARN_ON(1) instead.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
__WARN() is not defined for all configs, use WARN_ON(1) instead.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Fixup lwsync at runtime</title>
<updated>2008-07-03T06:58:10+00:00</updated>
<author>
<name>Kumar Gala</name>
<email>galak@kernel.crashing.org</email>
</author>
<published>2008-07-01T15:16:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2d1b2027626d5151fff8ef7c06ca8e7876a1a510'/>
<id>2d1b2027626d5151fff8ef7c06ca8e7876a1a510</id>
<content type='text'>
To allow for a single kernel image on e500 v1/v2/mc we need to fixup lwsync
at runtime.  On e500v1/v2 lwsync causes an illop so we need to patch up
the code.  We default to 'sync' since that is always safe and if the cpu
is capable we will replace 'sync' with 'lwsync'.

We introduce CPU_FTR_LWSYNC as a way to determine at runtime if this is
needed.  This flag could be moved elsewhere since we dont really use it
for the normal CPU_FTR purpose.

Finally we only store the relative offset in the fixup section to keep it
as small as possible rather than using a full fixup_entry.

Signed-off-by: Kumar Gala &lt;galak@kernel.crashing.org&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
To allow for a single kernel image on e500 v1/v2/mc we need to fixup lwsync
at runtime.  On e500v1/v2 lwsync causes an illop so we need to patch up
the code.  We default to 'sync' since that is always safe and if the cpu
is capable we will replace 'sync' with 'lwsync'.

We introduce CPU_FTR_LWSYNC as a way to determine at runtime if this is
needed.  This flag could be moved elsewhere since we dont really use it
for the normal CPU_FTR purpose.

Finally we only store the relative offset in the fixup section to keep it
as small as possible rather than using a full fixup_entry.

Signed-off-by: Kumar Gala &lt;galak@kernel.crashing.org&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Fix building of feature-fixup tests on ppc32</title>
<updated>2008-07-03T06:58:09+00:00</updated>
<author>
<name>Kumar Gala</name>
<email>galak@kernel.crashing.org</email>
</author>
<published>2008-07-01T15:16:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5888da18765ca9af7f10015263d8bc8e3057f128'/>
<id>5888da18765ca9af7f10015263d8bc8e3057f128</id>
<content type='text'>
We need to use PPC_LCMPI otherwise we get compile errors like:

arch/powerpc/lib/feature-fixups-test.S: Assembler messages:
arch/powerpc/lib/feature-fixups-test.S:142: Error: Unrecognized opcode: `cmpdi'
arch/powerpc/lib/feature-fixups-test.S:149: Error: Unrecognized opcode: `cmpdi'
arch/powerpc/lib/feature-fixups-test.S:164: Error: Unrecognized opcode: `cmpdi'

Signed-off-by: Kumar Gala &lt;galak@kernel.crashing.org&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We need to use PPC_LCMPI otherwise we get compile errors like:

arch/powerpc/lib/feature-fixups-test.S: Assembler messages:
arch/powerpc/lib/feature-fixups-test.S:142: Error: Unrecognized opcode: `cmpdi'
arch/powerpc/lib/feature-fixups-test.S:149: Error: Unrecognized opcode: `cmpdi'
arch/powerpc/lib/feature-fixups-test.S:164: Error: Unrecognized opcode: `cmpdi'

Signed-off-by: Kumar Gala &lt;galak@kernel.crashing.org&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Prevent memory corruption due to cache invalidation of unaligned DMA buffer</title>
<updated>2008-07-01T01:28:54+00:00</updated>
<author>
<name>Andrew Lewis</name>
<email>andrew-lewis@netspace.net.au</email>
</author>
<published>2008-06-26T09:29:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=03d70617b8a789c3721afaafde06fcbba7c7ebf1'/>
<id>03d70617b8a789c3721afaafde06fcbba7c7ebf1</id>
<content type='text'>
On PowerPC processors with non-coherent cache architectures the DMA
subsystem calls invalidate_dcache_range() before performing a DMA read
operation.  If the address and length of the DMA buffer are not aligned
to a cache-line boundary this can result in memory outside of the DMA
buffer being invalidated in the cache.  If this memory has an
uncommitted store then the data will be lost and a subsequent read of
that address will result in an old value being returned from main memory.

Only when the DMA buffer starts on a cache-line boundary and is an exact
mutiple of the cache-line size can invalidate_dcache_range() be called,
otherwise flush_dcache_range() must be called.  flush_dcache_range()
will first flush uncommitted writes, and then invalidate the cache.

Signed-off-by: Andrew Lewis &lt;andrew-lewis at netspace.net.au&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On PowerPC processors with non-coherent cache architectures the DMA
subsystem calls invalidate_dcache_range() before performing a DMA read
operation.  If the address and length of the DMA buffer are not aligned
to a cache-line boundary this can result in memory outside of the DMA
buffer being invalidated in the cache.  If this memory has an
uncommitted store then the data will be lost and a subsequent read of
that address will result in an old value being returned from main memory.

Only when the DMA buffer starts on a cache-line boundary and is an exact
mutiple of the cache-line size can invalidate_dcache_range() be called,
otherwise flush_dcache_range() must be called.  flush_dcache_range()
will first flush uncommitted writes, and then invalidate the cache.

Signed-off-by: Andrew Lewis &lt;andrew-lewis at netspace.net.au&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
