<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/arch/powerpc/lib/Makefile, branch linux-5.2.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.</subtitle>
<id>https://universe.0xinfinity.dev/distro/kernel/atom?h=linux-5.2.y</id>
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<updated>2019-05-02T15:20:26Z</updated>
<entry>
<title>powerpc: disable KASAN instrumentation on early/critical files.</title>
<updated>2019-05-02T15:20:26Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2019-04-26T16:23:33Z</published>
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<id>urn:sha1:f072015c7b742c42aa5649d22f43163cd0eb7024</id>
<content type='text'>
All files containing functions run before kasan_early_init() is called
must have KASAN instrumentation disabled.

For those file, branch profiling also have to be disabled otherwise
each if () generates a call to ftrace_likely_update().

Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>powerpc: prepare string/mem functions for KASAN</title>
<updated>2019-05-02T15:20:25Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2019-04-26T16:23:26Z</published>
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<id>urn:sha1:26deb04342e343ac58ab05bc7d2345ff0be9b667</id>
<content type='text'>
CONFIG_KASAN implements wrappers for memcpy() memmove() and memset()
Those wrappers are doing the verification then call respectively
__memcpy() __memmove() and __memset(). The arches are therefore
expected to rename their optimised functions that way.

For files on which KASAN is inhibited, #defines are used to allow
them to directly call optimised versions of the functions without
going through the KASAN wrappers.

See commit 393f203f5fd5 ("x86_64: kasan: add interceptors for
memset/memmove/memcpy functions") for details.

Other string / mem functions do not (yet) have kasan wrappers,
we therefore have to fallback to the generic versions when
KASAN is active, otherwise KASAN checks will be skipped.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
[mpe: Fixups to keep selftests working]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>powerpc: sstep: Add tests for compute type instructions</title>
<updated>2019-02-23T10:04:31Z</updated>
<author>
<name>Sandipan Das</name>
<email>sandipan@linux.ibm.com</email>
</author>
<published>2019-02-20T06:56:58Z</published>
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<id>urn:sha1:84022ac17327c5383917f46c162fd943cf79583f</id>
<content type='text'>
This enhances the current selftest framework for validating
the in-kernel instruction emulation infrastructure by adding
support for compute type instructions i.e. integer ALU-based
instructions. Originally, this framework was limited to only
testing load and store instructions.

While most of the GPRs can be validated, support for SPRs is
limited to LR, CR and XER for now.

When writing the test cases, one must ensure that the Stack
Pointer (GPR1) or the Thread Pointer (GPR13) are not touched
by any means as these are vital non-volatile registers.

Signed-off-by: Sandipan Das &lt;sandipan@linux.ibm.com&gt;
[mpe: Use patch_site for the code patching]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>powerpc: Add support for function error injection</title>
<updated>2018-10-20T02:26:43Z</updated>
<author>
<name>Naveen N. Rao</name>
<email>naveen.n.rao@linux.vnet.ibm.com</email>
</author>
<published>2018-06-07T09:52:02Z</published>
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<id>urn:sha1:7cd01b08d35f1b7d55686ed8cd57c94d3406ec8f</id>
<content type='text'>
We implement regs_set_return_value() and override_function_with_return()
for this purpose.

On powerpc, a return from a function (blr) just branches to the location
contained in the link register. So, we can just update pt_regs rather
than redirecting execution to a dummy function that returns.

Signed-off-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Reviewed-by: Samuel Mendoza-Jonas &lt;sam@mendozajonas.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>powerpc: Add -Werror at arch/powerpc level</title>
<updated>2018-10-18T13:56:17Z</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2018-10-10T05:13:06Z</published>
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<id>urn:sha1:23ad1a2700725d46ee7760920974c68be81ab82d</id>
<content type='text'>
Back when I added -Werror in commit ba55bd74360e ("powerpc: Add
configurable -Werror for arch/powerpc") I did it by adding it to most
of the arch Makefiles.

At the time we excluded math-emu, because apparently it didn't build
cleanly. But that seems to have been fixed somewhere in the interim.

So move the -Werror addition to the top-level of the arch, this saves
us from repeating it in every Makefile and means we won't forget to
add it to any new sub-dirs.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>powerpc/lib: Implement strlen() in assembly for PPC32</title>
<updated>2018-08-07T11:49:30Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2018-08-01T09:01:14Z</published>
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<id>urn:sha1:9412b234501eef1d273cc759387a232f0027c574</id>
<content type='text'>
The generic implementation of strlen() reads strings byte per byte.

This patch implements strlen() in assembly based on a read of entire
words, in the same spirit as what some other arches and glibc do.

On a 8xx the time spent in strlen is reduced by 3/4 for long strings.

strlen() selftest on an 8xx provides the following values:

Before the patch (ie with the generic strlen() in lib/string.c):

  len 256 : time = 1.195055
  len 016 : time = 0.083745
  len 008 : time = 0.046828
  len 004 : time = 0.028390

After the patch:

  len 256 : time = 0.272185 ==&gt; 78% improvment
  len 016 : time = 0.040632 ==&gt; 51% improvment
  len 008 : time = 0.033060 ==&gt; 29% improvment
  len 004 : time = 0.029149 ==&gt; 2% degradation

On a 832x:

Before the patch:

  len 256 : time = 0.236125
  len 016 : time = 0.018136
  len 008 : time = 0.011000
  len 004 : time = 0.007229

After the patch:

  len 256 : time = 0.094950 ==&gt; 60% improvment
  len 016 : time = 0.013357 ==&gt; 26% improvment
  len 008 : time = 0.010586 ==&gt; 4% improvment
  len 004 : time = 0.008784

Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>powerpc/lib: optimise PPC32 memcmp</title>
<updated>2018-06-03T14:39:21Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2018-05-30T07:06:15Z</published>
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<id>urn:sha1:2676b89eb82f56825d7289edf21f17a6461388b7</id>
<content type='text'>
At the time being, memcmp() compares two chunks of memory
byte per byte.

This patch optimises the comparison by comparing word by word.

On the same way as commit 15c2d45d17418 ("powerpc: Add 64bit
optimised memcmp"), this patch moves memcmp() into a dedicated
file named memcmp_32.S

A small benchmark performed on an 8xx comparing two chuncks
of 512 bytes performed 100000 times gives:

Before : 5852274 TB ticks
After:   1488638 TB ticks

This is almost 4 times faster

Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>powerpc/lib: optimise 32 bits __clear_user()</title>
<updated>2018-06-03T14:39:21Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2018-05-30T07:06:13Z</published>
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<id>urn:sha1:f36bbf21e8b911b3c629fd36d4d217105b47a20e</id>
<content type='text'>
Rewrite clear_user() on the same principle as memset(0), making use
of dcbz to clear complete cache lines.

This code is a copy/paste of memset(), with some modifications
in order to retrieve remaining number of bytes to be cleared,
as it needs to be returned in case of error.

On the same way as done on PPC64 in commit 17968fbbd19f1
("powerpc: 64bit optimised __clear_user"), the patch moves
__clear_user() into a dedicated file string_32.S

On a MPC885, throughput is almost doubled:

Before:
~# dd if=/dev/zero of=/dev/null bs=1M count=1000
1048576000 bytes (1000.0MB) copied, 18.990779 seconds, 52.7MB/s

After:
~# dd if=/dev/zero of=/dev/null bs=1M count=1000
1048576000 bytes (1000.0MB) copied, 9.611468 seconds, 104.0MB/s

On a MPC8321, throughput is multiplied by 2.12:

Before:
root@vgoippro:~# dd if=/dev/zero of=/dev/null bs=1M count=1000
1048576000 bytes (1000.0MB) copied, 6.844352 seconds, 146.1MB/s

After:
root@vgoippro:~# dd if=/dev/zero of=/dev/null bs=1M count=1000
1048576000 bytes (1000.0MB) copied, 3.218854 seconds, 310.7MB/s

Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>powerpc/64s: Set assembler machine type to POWER4</title>
<updated>2018-03-31T13:47:49Z</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2018-02-20T19:08:26Z</published>
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<id>urn:sha1:15a3204d24a3c01b116fb7c0692b7c670cac631d</id>
<content type='text'>
Rather than override the machine type in .S code (which can hide wrong
or ambiguous code generation for the target), set the type to power4
for all assembly.

This also means we need to be careful not to build power4-only code
when we're not building for Book3S, such as the "power7" versions of
copyuser/page/memcpy.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
[mpe: Fix Book3E build, don't build the "power7" variants for non-Book3S]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>Merge tag 'powerpc-4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2017-11-16T20:47:46Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-11-16T20:47:46Z</published>
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<id>urn:sha1:5b0e2cb020085efe202123162502e0b551e49a0e</id>
<content type='text'>
Pull powerpc updates from Michael Ellerman:
 "A bit of a small release, I suspect in part due to me travelling for
  KS. But my backlog of patches to review is smaller than usual, so I
  think in part folks just didn't send as much this cycle.

  Non-highlights:

   - Five fixes for the &gt;128T address space handling, both to fix bugs
     in our implementation and to bring the semantics exactly into line
     with x86.

  Highlights:

   - Support for a new OPAL call on bare metal machines which gives us a
     true NMI (ie. is not masked by MSR[EE]=0) for debugging etc.

   - Support for Power9 DD2 in the CXL driver.

   - Improvements to machine check handling so that uncorrectable errors
     can be reported into the generic memory_failure() machinery.

   - Some fixes and improvements for VPHN, which is used under PowerVM
     to notify the Linux partition of topology changes.

   - Plumbing to enable TM (transactional memory) without suspend on
     some Power9 processors (PPC_FEATURE2_HTM_NO_SUSPEND).

   - Support for emulating vector loads form cache-inhibited memory, on
     some Power9 revisions.

   - Disable the fast-endian switch "syscall" by default (behind a
     CONFIG), we believe it has never had any users.

   - A major rework of the API drivers use when initiating and waiting
     for long running operations performed by OPAL firmware, and changes
     to the powernv_flash driver to use the new API.

   - Several fixes for the handling of FP/VMX/VSX while processes are
     using transactional memory.

   - Optimisations of TLB range flushes when using the radix MMU on
     Power9.

   - Improvements to the VAS facility used to access coprocessors on
     Power9, and related improvements to the way the NX crypto driver
     handles requests.

   - Implementation of PMEM_API and UACCESS_FLUSHCACHE for 64-bit.

  Thanks to: Alexey Kardashevskiy, Alistair Popple, Allen Pais, Andrew
  Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Balbir Singh, Benjamin
  Herrenschmidt, Breno Leitao, Christophe Leroy, Christophe Lombard,
  Cyril Bur, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven,
  Guilherme G. Piccoli, Gustavo Romero, Haren Myneni, Joel Stanley,
  Kamalesh Babulal, Kautuk Consul, Markus Elfring, Masami Hiramatsu,
  Michael Bringmann, Michael Neuling, Michal Suchanek, Naveen N. Rao,
  Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pedro Miraglia
  Franco de Carvalho, Philippe Bergheaud, Sandipan Das, Seth Forshee,
  Shriya, Stephen Rothwell, Stewart Smith, Sukadev Bhattiprolu, Tyrel
  Datwyler, Vaibhav Jain, Vaidyanathan Srinivasan, and William A.
  Kennington III"

* tag 'powerpc-4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (151 commits)
  powerpc/64s: Fix Power9 DD2.0 workarounds by adding DD2.1 feature
  powerpc/64s: Fix masking of SRR1 bits on instruction fault
  powerpc/64s: mm_context.addr_limit is only used on hash
  powerpc/64s/radix: Fix 128TB-512TB virtual address boundary case allocation
  powerpc/64s/hash: Allow MAP_FIXED allocations to cross 128TB boundary
  powerpc/64s/hash: Fix fork() with 512TB process address space
  powerpc/64s/hash: Fix 128TB-512TB virtual address boundary case allocation
  powerpc/64s/hash: Fix 512T hint detection to use &gt;= 128T
  powerpc: Fix DABR match on hash based systems
  powerpc/signal: Properly handle return value from uprobe_deny_signal()
  powerpc/fadump: use kstrtoint to handle sysfs store
  powerpc/lib: Implement UACCESS_FLUSHCACHE API
  powerpc/lib: Implement PMEM API
  powerpc/powernv/npu: Don't explicitly flush nmmu tlb
  powerpc/powernv/npu: Use flush_all_mm() instead of flush_tlb_mm()
  powerpc/powernv/idle: Round up latency and residency values
  powerpc/kprobes: refactor kprobe_lookup_name for safer string operations
  powerpc/kprobes: Blacklist emulate_update_regs() from kprobes
  powerpc/kprobes: Do not disable interrupts for optprobes and kprobes_on_ftrace
  powerpc/kprobes: Disable preemption before invoking probe handler for optprobes
  ...
</content>
</entry>
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