<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/tools/include/asm, branch v6.16-rc5</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>lib/rbtree: enable userland test suite for rbtree related data structure</title>
<updated>2025-03-17T19:17:00+00:00</updated>
<author>
<name>Wei Yang</name>
<email>richard.weiyang@gmail.com</email>
</author>
<published>2025-03-10T07:49:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4164e1525d37d463bbd0a808709fd75abcfc89a5'/>
<id>4164e1525d37d463bbd0a808709fd75abcfc89a5</id>
<content type='text'>
Patch series "lib/interval_tree: add some test cases and cleanup", v2.

Since rbtree/augmented tree/interval tree share similar data structure,
besides new cases for interval tree, this patch set also does cleanup for
others.


This patch (of 7):

Currently we have some tests for rbtree related data structure, e.g. 
rbtree, augmented rbtree, interval tree, in lib/ as kernel module.

To facilitate the test and debug for those fundamental data structure,
this patch enable those tests in userland.

Link: https://lkml.kernel.org/r/20250310074938.26756-1-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20250310074938.26756-2-richard.weiyang@gmail.com
Signed-off-by: Wei Yang &lt;richard.weiyang@gmail.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Michel Lespinasse &lt;michel@lespinasse.org&gt;
Cc: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Patch series "lib/interval_tree: add some test cases and cleanup", v2.

Since rbtree/augmented tree/interval tree share similar data structure,
besides new cases for interval tree, this patch set also does cleanup for
others.


This patch (of 7):

Currently we have some tests for rbtree related data structure, e.g. 
rbtree, augmented rbtree, interval tree, in lib/ as kernel module.

To facilitate the test and debug for those fundamental data structure,
this patch enable those tests in userland.

Link: https://lkml.kernel.org/r/20250310074938.26756-1-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20250310074938.26756-2-richard.weiyang@gmail.com
Signed-off-by: Wei Yang &lt;richard.weiyang@gmail.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Michel Lespinasse &lt;michel@lespinasse.org&gt;
Cc: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'riscv-for-linus-6.12-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux</title>
<updated>2024-09-24T17:59:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-24T17:59:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=97d8894b6f4c44762fd48f5d29e73358d6181dbb'/>
<id>97d8894b6f4c44762fd48f5d29e73358d6181dbb</id>
<content type='text'>
Pull RISC-V updates from Palmer Dabbelt:

 - Support using Zkr to seed KASLR

 - Support IPI-triggered CPU backtracing

 - Support for generic CPU vulnerabilities reporting to userspace

 - A few cleanups for missing licenses

 - The size limit on the XIP kernel has been removed

 - Support for tracing userspace stacks

 - Support for the Svvptc extension

 - Various cleanups and fixes throughout the tree

* tag 'riscv-for-linus-6.12-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (47 commits)
  crash: Fix riscv64 crash memory reserve dead loop
  perf/riscv-sbi: Add platform specific firmware event handling
  tools: Optimize ring buffer for riscv
  tools: Add riscv barrier implementation
  RISC-V: Don't have MAX_PHYSMEM_BITS exceed phys_addr_t
  ACPI: NUMA: initialize all values of acpi_early_node_map to NUMA_NO_NODE
  riscv: Enable bitops instrumentation
  riscv: Omit optimized string routines when using KASAN
  ACPI: RISCV: Make acpi_numa_get_nid() to be static
  riscv: Randomize lower bits of stack address
  selftests: riscv: Allow mmap test to compile on 32-bit
  riscv: Make riscv_isa_vendor_ext_andes array static
  riscv: Use LIST_HEAD() to simplify code
  riscv: defconfig: Disable RZ/Five peripheral support
  RISC-V: Implement kgdb_roundup_cpus() to enable future NMI Roundup
  riscv: avoid Imbalance in RAS
  riscv: cacheinfo: Add back init_cache_level() function
  riscv: Remove unused _TIF_WORK_MASK
  drivers/perf: riscv: Remove redundant macro check
  riscv: define ILLEGAL_POINTER_VALUE for 64bit
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull RISC-V updates from Palmer Dabbelt:

 - Support using Zkr to seed KASLR

 - Support IPI-triggered CPU backtracing

 - Support for generic CPU vulnerabilities reporting to userspace

 - A few cleanups for missing licenses

 - The size limit on the XIP kernel has been removed

 - Support for tracing userspace stacks

 - Support for the Svvptc extension

 - Various cleanups and fixes throughout the tree

* tag 'riscv-for-linus-6.12-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (47 commits)
  crash: Fix riscv64 crash memory reserve dead loop
  perf/riscv-sbi: Add platform specific firmware event handling
  tools: Optimize ring buffer for riscv
  tools: Add riscv barrier implementation
  RISC-V: Don't have MAX_PHYSMEM_BITS exceed phys_addr_t
  ACPI: NUMA: initialize all values of acpi_early_node_map to NUMA_NO_NODE
  riscv: Enable bitops instrumentation
  riscv: Omit optimized string routines when using KASAN
  ACPI: RISCV: Make acpi_numa_get_nid() to be static
  riscv: Randomize lower bits of stack address
  selftests: riscv: Allow mmap test to compile on 32-bit
  riscv: Make riscv_isa_vendor_ext_andes array static
  riscv: Use LIST_HEAD() to simplify code
  riscv: defconfig: Disable RZ/Five peripheral support
  RISC-V: Implement kgdb_roundup_cpus() to enable future NMI Roundup
  riscv: avoid Imbalance in RAS
  riscv: cacheinfo: Add back init_cache_level() function
  riscv: Remove unused _TIF_WORK_MASK
  drivers/perf: riscv: Remove redundant macro check
  riscv: define ILLEGAL_POINTER_VALUE for 64bit
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>tools: Add riscv barrier implementation</title>
<updated>2024-09-20T08:46:46+00:00</updated>
<author>
<name>Charlie Jenkins</name>
<email>charlie@rivosinc.com</email>
</author>
<published>2024-08-06T22:01:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6d74d178fe6eaf61e384f3be6ba64150bddce8a6'/>
<id>6d74d178fe6eaf61e384f3be6ba64150bddce8a6</id>
<content type='text'>
Many of the other architectures use their custom barrier implementations.
Use the barrier code from the kernel sources to optimize barriers in
tools.

Signed-off-by: Charlie Jenkins &lt;charlie@rivosinc.com&gt;
Reviewed-by: Andrea Parri &lt;parri.andrea@gmail.com&gt;
Link: https://lore.kernel.org/r/20240806-optimize_ring_buffer_read_riscv-v2-1-ca7e193ae198@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Many of the other architectures use their custom barrier implementations.
Use the barrier code from the kernel sources to optimize barriers in
tools.

Signed-off-by: Charlie Jenkins &lt;charlie@rivosinc.com&gt;
Reviewed-by: Andrea Parri &lt;parri.andrea@gmail.com&gt;
Link: https://lore.kernel.org/r/20240806-optimize_ring_buffer_read_riscv-v2-1-ca7e193ae198@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests: vDSO: check cpu caps before running chacha test</title>
<updated>2024-09-16T11:22:04+00:00</updated>
<author>
<name>Jason A. Donenfeld</name>
<email>Jason@zx2c4.com</email>
</author>
<published>2024-09-14T23:07:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=210860e7f7337e47e77577fa5bb168767e2d8a1e'/>
<id>210860e7f7337e47e77577fa5bb168767e2d8a1e</id>
<content type='text'>
Some archs -- arm64 and s390x -- implemented chacha using instructions
that are available most places, but aren't always available. The kernel
handles this just fine, but the selftest does not. Check the hwcaps
before running, and skip the test if the cpu doesn't support it. As
well, on s390x, always emit the fallback instructions of an alternative
block, to ensure maximum compatibility.

Co-developed-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Some archs -- arm64 and s390x -- implemented chacha using instructions
that are available most places, but aren't always available. The kernel
handles this just fine, but the selftest does not. Check the hwcaps
before running, and skip the test if the cpu doesn't support it. As
well, on s390x, always emit the fallback instructions of an alternative
block, to ensure maximum compatibility.

Co-developed-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/vDSO: add tests for vgetrandom</title>
<updated>2024-07-19T18:22:12+00:00</updated>
<author>
<name>Jason A. Donenfeld</name>
<email>Jason@zx2c4.com</email>
</author>
<published>2024-07-06T23:40:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4920a2590e91bc15068e789aaf4ddc522f772fc5'/>
<id>4920a2590e91bc15068e789aaf4ddc522f772fc5</id>
<content type='text'>
This adds two tests for vgetrandom. The first one, vdso_test_chacha,
simply checks that the assembly implementation of chacha20 matches that
of libsodium, a basic sanity check that should catch most errors. The
second, vdso_test_getrandom, is a full "libc-like" implementation of the
userspace side of vgetrandom() support. It's meant to be used also as
example code for libcs that might be integrating this.

Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This adds two tests for vgetrandom. The first one, vdso_test_chacha,
simply checks that the assembly implementation of chacha20 matches that
of libsodium, a basic sanity check that should catch most errors. The
second, vdso_test_getrandom, is a full "libc-like" implementation of the
userspace side of vgetrandom() support. It's meant to be used also as
example code for libcs that might be integrating this.

Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools headers: Update the copy of x86's mem{cpy,set}_64.S used in 'perf bench'</title>
<updated>2023-05-17T13:42:19+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2023-05-17T13:34:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7f02ce62a6cfc0feb164bb7eb36c6647c00b43c8'/>
<id>7f02ce62a6cfc0feb164bb7eb36c6647c00b43c8</id>
<content type='text'>
This is to get the changes from:

  68674f94ffc9dddc ("x86: don't use REP_GOOD or ERMS for small memory copies")
  20f3337d350c4e1b ("x86: don't use REP_GOOD or ERMS for small memory clearing")

This also make the 'perf bench mem' files stop referring to the erms
versions that gone away with the above patches.

That addresses these perf tools build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
  diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S
  Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S'
  diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S

Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is to get the changes from:

  68674f94ffc9dddc ("x86: don't use REP_GOOD or ERMS for small memory copies")
  20f3337d350c4e1b ("x86: don't use REP_GOOD or ERMS for small memory clearing")

This also make the 'perf bench mem' files stop referring to the erms
versions that gone away with the above patches.

That addresses these perf tools build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
  diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S
  Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S'
  diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S

Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nds32: Remove the architecture</title>
<updated>2022-03-07T12:54:59+00:00</updated>
<author>
<name>Alan Kao</name>
<email>alankao@andestech.com</email>
</author>
<published>2022-03-02T07:42:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=aec499c75cf8e0b599be4d559e6922b613085f8f'/>
<id>aec499c75cf8e0b599be4d559e6922b613085f8f</id>
<content type='text'>
The nds32 architecture, also known as AndeStar V3, is a custom 32-bit
RISC target designed by Andes Technologies. Support was added to the
kernel in 2016 as the replacement RISC-V based V5 processors were
already announced, and maintained by (current or former) Andes
employees.

As explained by Alan Kao, new customers are now all using RISC-V,
and all known nds32 users are already on longterm stable kernels
provided by Andes, with no development work going into mainline
support any more.

While the port is still in a reasonably good shape, it only gets
worse over time without active maintainers, so it seems best
to remove it before it becomes unusable. As always, if it turns
out that there are mainline users after all, and they volunteer
to maintain the port in the future, the removal can be reverted.

Link: https://lore.kernel.org/linux-mm/YhdWNLUhk+x9RAzU@yamatobi.andestech.com/
Link: https://lore.kernel.org/lkml/20220302065213.82702-1-alankao@andestech.com/
Link: https://www.andestech.com/en/products-solutions/andestar-architecture/
Signed-off-by: Alan Kao &lt;alankao@andestech.com&gt;
[arnd: rewrite changelog to provide more background]
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The nds32 architecture, also known as AndeStar V3, is a custom 32-bit
RISC target designed by Andes Technologies. Support was added to the
kernel in 2016 as the replacement RISC-V based V5 processors were
already announced, and maintained by (current or former) Andes
employees.

As explained by Alan Kao, new customers are now all using RISC-V,
and all known nds32 users are already on longterm stable kernels
provided by Andes, with no development work going into mainline
support any more.

While the port is still in a reasonably good shape, it only gets
worse over time without active maintainers, so it seems best
to remove it before it becomes unusable. As always, if it turns
out that there are mainline users after all, and they volunteer
to maintain the port in the future, the removal can be reverted.

Link: https://lore.kernel.org/linux-mm/YhdWNLUhk+x9RAzU@yamatobi.andestech.com/
Link: https://lore.kernel.org/lkml/20220302065213.82702-1-alankao@andestech.com/
Link: https://www.andestech.com/en/products-solutions/andestar-architecture/
Signed-off-by: Alan Kao &lt;alankao@andestech.com&gt;
[arnd: rewrite changelog to provide more background]
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools arch: Update arch/x86/lib/mem{cpy,set}_64.S copies used in 'perf bench mem memcpy'</title>
<updated>2021-05-10T12:01:00+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2021-05-09T13:19:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fb24e308b6310541e70d11a3f19dc40742974b95'/>
<id>fb24e308b6310541e70d11a3f19dc40742974b95</id>
<content type='text'>
To bring in the change made in this cset:

 5e21a3ecad1500e3 ("x86/alternative: Merge include files")

This just silences these perf tools build warnings, no change in the tools:

  Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
  diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S
  Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S'
  diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S

Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
To bring in the change made in this cset:

 5e21a3ecad1500e3 ("x86/alternative: Merge include files")

This just silences these perf tools build warnings, no change in the tools:

  Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
  diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S
  Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S'
  diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S

Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools: Add missing stdio.h include to asm/bug.h header</title>
<updated>2019-09-25T12:51:44+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2019-09-12T08:57:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=058bd857845a9675cfaf4bc2ca831ec7953b58f1'/>
<id>058bd857845a9675cfaf4bc2ca831ec7953b58f1</id>
<content type='text'>
We have a direct fprintf() call in the header, so we need stdio.h
include, otherwise it could fail compilation if there's no prior stdio.h
include directive.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: http://lkml.kernel.org/n/tip-8hvjgh24olfsa4non0a3ohnq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We have a direct fprintf() call in the header, so we need stdio.h
include, otherwise it could fail compilation if there's no prior stdio.h
include directive.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: http://lkml.kernel.org/n/tip-8hvjgh24olfsa4non0a3ohnq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nds32: Perf porting</title>
<updated>2018-11-06T10:01:40+00:00</updated>
<author>
<name>Nickhu</name>
<email>nickhu@andestech.com</email>
</author>
<published>2018-10-25T02:24:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ebd09753b5707cc083c52e1d0ec7f45dccdb73bf'/>
<id>ebd09753b5707cc083c52e1d0ec7f45dccdb73bf</id>
<content type='text'>
This is the commit that porting the perf for nds32.

1.Raw event:
	The raw events start with 'r'.
		Usage:
			perf stat -e rXYZ ./app
			X: the index of performance counter.
			YZ: the index(convert to hexdecimal) of events

		Example:
			'perf stat -e r101 ./app' means the counter 1 will count the instruction
		event.

		The index of counter and events can be found in
		"Andes System Privilege Architecture Version 3 Manual".

Or you can perform the 'perf list' to find the symbolic name of raw events.

2.Perf mmap2:

	Fix unexpected perf mmap2() page fault

	When the mmap2() called by perf application,
	you will encounter such condition:"failed to write."
	With return value -EFAULT

	This is due to the page fault caused by "reading" buffer
	from the mapped legal address region to write to the descriptor.
	The page_fault handler will get a VM_FAULT_SIGBUS return value,
	which should not happens here.(Due to this is a read request.)

	You can refer to kernel/events/core.c:perf_mmap_fault(...)
	If "(vmf-&gt;pgoff &amp;&amp; (vmf-&gt;flags &amp; FAULT_FLAG_WRITE))" is evaluated
	as true, you will get VM_FAULT_SIGBUS as return value.

	However, this is not an write request. The flags which indicated
	why the page fault happens is wrong.

	Furthermore, NDS32 SPAv3 is not able to detect it is read or write.
	It only know  either it is instruction fetch or data access.

	Therefore, by removing the wrong flag assignment(actually, the hardware
	is not able to show the reason), we can fix this bug.

3.Perf multiple events map to same counter.

	When there are multiple events map to the same counter, the counter
	counts inaccurately. This is because each counter only counts one event
	in the same time.
	So when there are multiple events map to same counter, they have to take
	turns in each context.

	There are two solution:
	1. Print the error message when multiple events map to the same counter.
	But print the error message would let the program hang in loop. The ltp
	(linux test program) would be failed when the program hang in loop.

	2. Don't print the error message, the ltp would pass. But the user need to
	have the knowledge that don't count the events which map to the same
	counter, or the user will get the inaccurate results.

	We choose method 2 for the solution

Signed-off-by: Nickhu &lt;nickhu@andestech.com&gt;
Acked-by: Greentime Hu &lt;greentime@andestech.com&gt;
Signed-off-by: Greentime Hu &lt;greentime@andestech.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is the commit that porting the perf for nds32.

1.Raw event:
	The raw events start with 'r'.
		Usage:
			perf stat -e rXYZ ./app
			X: the index of performance counter.
			YZ: the index(convert to hexdecimal) of events

		Example:
			'perf stat -e r101 ./app' means the counter 1 will count the instruction
		event.

		The index of counter and events can be found in
		"Andes System Privilege Architecture Version 3 Manual".

Or you can perform the 'perf list' to find the symbolic name of raw events.

2.Perf mmap2:

	Fix unexpected perf mmap2() page fault

	When the mmap2() called by perf application,
	you will encounter such condition:"failed to write."
	With return value -EFAULT

	This is due to the page fault caused by "reading" buffer
	from the mapped legal address region to write to the descriptor.
	The page_fault handler will get a VM_FAULT_SIGBUS return value,
	which should not happens here.(Due to this is a read request.)

	You can refer to kernel/events/core.c:perf_mmap_fault(...)
	If "(vmf-&gt;pgoff &amp;&amp; (vmf-&gt;flags &amp; FAULT_FLAG_WRITE))" is evaluated
	as true, you will get VM_FAULT_SIGBUS as return value.

	However, this is not an write request. The flags which indicated
	why the page fault happens is wrong.

	Furthermore, NDS32 SPAv3 is not able to detect it is read or write.
	It only know  either it is instruction fetch or data access.

	Therefore, by removing the wrong flag assignment(actually, the hardware
	is not able to show the reason), we can fix this bug.

3.Perf multiple events map to same counter.

	When there are multiple events map to the same counter, the counter
	counts inaccurately. This is because each counter only counts one event
	in the same time.
	So when there are multiple events map to same counter, they have to take
	turns in each context.

	There are two solution:
	1. Print the error message when multiple events map to the same counter.
	But print the error message would let the program hang in loop. The ltp
	(linux test program) would be failed when the program hang in loop.

	2. Don't print the error message, the ltp would pass. But the user need to
	have the knowledge that don't count the events which map to the same
	counter, or the user will get the inaccurate results.

	We choose method 2 for the solution

Signed-off-by: Nickhu &lt;nickhu@andestech.com&gt;
Acked-by: Greentime Hu &lt;greentime@andestech.com&gt;
Signed-off-by: Greentime Hu &lt;greentime@andestech.com&gt;
</pre>
</div>
</content>
</entry>
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