<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/arch/arc/include/asm, branch v4.20</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.20</id>
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<updated>2018-11-30T19:26:29Z</updated>
<entry>
<title>ARC: io.h: Implement reads{x}()/writes{x}()</title>
<updated>2018-11-30T19:26:29Z</updated>
<author>
<name>Jose Abreu</name>
<email>joabreu@synopsys.com</email>
</author>
<published>2018-11-30T09:47:31Z</published>
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<id>urn:sha1:10d443431dc2bb733cf7add99b453e3fb9047a2e</id>
<content type='text'>
Some ARC CPU's do not support unaligned loads/stores. Currently, generic
implementation of reads{b/w/l}()/writes{b/w/l}() is being used with ARC.
This can lead to misfunction of some drivers as generic functions do a
plain dereference of a pointer that can be unaligned.

Let's use {get/put}_unaligned() helpers instead of plain dereference of
pointer in order to fix. The helpers allow to get and store data from an
unaligned address whilst preserving the CPU internal alignment.
According to [1], the use of these helpers are costly in terms of
performance so we added an initial check for a buffer already aligned so
that the usage of the helpers can be avoided, when possible.

[1] Documentation/unaligned-memory-access.txt

Cc: Alexey Brodkin &lt;abrodkin@synopsys.com&gt;
Cc: Joao Pinto &lt;jpinto@synopsys.com&gt;
Cc: David Laight &lt;David.Laight@ACULAB.COM&gt;
Tested-by: Vitor Soares &lt;soares@synopsys.com&gt;
Signed-off-by: Jose Abreu &lt;joabreu@synopsys.com&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</content>
</entry>
<entry>
<title>ARC: IOC: panic if kernel was started with previously enabled IOC</title>
<updated>2018-11-12T18:38:27Z</updated>
<author>
<name>Eugeniy Paltsev</name>
<email>Eugeniy.Paltsev@synopsys.com</email>
</author>
<published>2018-10-04T13:12:12Z</published>
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<id>urn:sha1:3624379d90ad2b65f9dbb30d7f7ce5498d2fe322</id>
<content type='text'>
If IOC was already enabled (due to bootloader) it technically needs to
be reconfigured with aperture base,size corresponding to Linux memory map
which will certainly be different than uboot's. But disabling and
reenabling IOC when DMA might be potentially active is tricky business.
To avoid random memory issues later, just panic here and ask user to
upgrade bootloader to one which doesn't enable IOC

This was actually seen as issue on some of the HSDK board with a version
of uboot which enabled IOC. There were random issues later with starting
of X or peripherals etc.

Also while I'm at it, replace hardcoded bits in ARC_REG_IO_COH_PARTIAL
and ARC_REG_IO_COH_ENABLE registers by definitions.

Inspired by: https://lkml.org/lkml/2018/1/19/557
Signed-off-by: Eugeniy Paltsev &lt;Eugeniy.Paltsev@synopsys.com&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</content>
</entry>
<entry>
<title>treewide: remove current_text_addr</title>
<updated>2018-10-31T15:54:12Z</updated>
<author>
<name>Nick Desaulniers</name>
<email>ndesaulniers@google.com</email>
</author>
<published>2018-10-30T22:04:47Z</published>
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<id>urn:sha1:de0d22e50cd3d57277f073ccf65d57aa519d6888</id>
<content type='text'>
Prefer _THIS_IP_ defined in linux/kernel.h.

Most definitions of current_text_addr were the same as _THIS_IP_, but
a few archs had inline assembly instead.

This patch removes the final call site of current_text_addr, making all
of the definitions dead code.

[akpm@linux-foundation.org: fix arch/csky/include/asm/processor.h]
Link: http://lkml.kernel.org/r/20180911182413.180715-1-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.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>
</entry>
<entry>
<title>ARC: dma [IOC] Enable per device io coherency</title>
<updated>2018-09-04T20:21:37Z</updated>
<author>
<name>Eugeniy Paltsev</name>
<email>Eugeniy.Paltsev@synopsys.com</email>
</author>
<published>2018-07-30T16:26:34Z</published>
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<id>urn:sha1:2820a708d5a321342bef34e459fdc8679c30e20f</id>
<content type='text'>
So far the IOC treatment was global on ARC, being turned on (or off)
for all devices in the system. With this patch, this can now be done
per device using the "dma-coherent" DT property; IOW with this patch
we can use both HW-coherent and regular DMA peripherals simultaneously.

The changes involved are too many so enlisting the summary below:

1. common code calls ARC arch_setup_dma_ops() per device.

2. For coherent dma (IOC) it plugs in generic @dma_direct_ops which
   doesn't need any arch specific backend: No need for any explicit
   cache flushes or MMU mappings to provide for uncached access

   - dma_(map|sync)_single* return early as corresponding dma ops callbacks
     are NULL in generic code.
     So arch_sync_dma_*() -&gt; dma_cache_*() need not handle the coherent
     dma case, hence drop ARC __dma_cache_*_ioc() which were no-op anyways

3. For noncoherent dma (non IOC) generic @dma_noncoherent_ops is used
   which in turns calls ARC specific routines

   - arch_dma_alloc() no longer checks for @ioc_enable since this is
     called only for !IOC case.

Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Eugeniy Paltsev &lt;Eugeniy.Paltsev@synopsys.com&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
[vgupta: rewrote changelog]
</content>
</entry>
<entry>
<title>ARC: atomics: unbork atomic_fetch_##op()</title>
<updated>2018-08-31T17:14:51Z</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2018-08-30T20:52:38Z</published>
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<id>urn:sha1:3fcbb8260a87efb691d837e8cd24e81f65b3eb70</id>
<content type='text'>
In 4.19-rc1, Eugeniy reported weird boot and IO errors on ARC HSDK

| INFO: task syslogd:77 blocked for more than 10 seconds.
|       Not tainted 4.19.0-rc1-00007-gf213acea4e88 #40
| "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this
| message.
| syslogd         D    0    77     76 0x00000000
|
| Stack Trace:
|  __switch_to+0x0/0xac
|  __schedule+0x1b2/0x730
|  io_schedule+0x5c/0xc0
|  __lock_page+0x98/0xdc
|  find_lock_entry+0x38/0x100
|  shmem_getpage_gfp.isra.3+0x82/0xbfc
|  shmem_fault+0x46/0x138
|  handle_mm_fault+0x5bc/0x924
|  do_page_fault+0x100/0x2b8
|  ret_from_exception+0x0/0x8

He bisected to 84c6591103db ("locking/atomics,
asm-generic/bitops/lock.h: Rewrite using atomic_fetch_*()")

This commit however only unmasked the real issue introduced by commit
4aef66c8ae9 ("locking/atomic, arch/arc: Fix build") which missed the
retry-if-scond-failed branch in atomic_fetch_##op() macros.

The bisected commit started using atomic_fetch_##op() macros for building
the rest of atomics.

Fixes: 4aef66c8ae9 ("locking/atomic, arch/arc: Fix build")
Reported-by: Eugeniy Paltsev &lt;paltsev@synopsys.com&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
[vgupta: wrote changelog]
</content>
</entry>
<entry>
<title>Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2018-08-13T19:55:49Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-08-13T19:55:49Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=8603596a327c978534f5c45db135e6c36b4b1425'/>
<id>urn:sha1:8603596a327c978534f5c45db135e6c36b4b1425</id>
<content type='text'>
Pull perf update from Thomas Gleixner:
 "The perf crowd presents:

  Kernel updates:

   - Removal of jprobes

   - Cleanup and consolidatation the handling of kprobes

   - Cleanup and consolidation of hardware breakpoints

   - The usual pile of fixes and updates to PMUs and event descriptors

  Tooling updates:

   - Updates and improvements all over the place. Nothing outstanding,
     just the (good) boring incremental grump work"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits)
  perf trace: Do not require --no-syscalls to suppress strace like output
  perf bpf: Include uapi/linux/bpf.h from the 'perf trace' script's bpf.h
  perf tools: Allow overriding MAX_NR_CPUS at compile time
  perf bpf: Show better message when failing to load an object
  perf list: Unify metric group description format with PMU event description
  perf vendor events arm64: Update ThunderX2 implementation defined pmu core events
  perf cs-etm: Generate branch sample for CS_ETM_TRACE_ON packet
  perf cs-etm: Generate branch sample when receiving a CS_ETM_TRACE_ON packet
  perf cs-etm: Support dummy address value for CS_ETM_TRACE_ON packet
  perf cs-etm: Fix start tracing packet handling
  perf build: Fix installation directory for eBPF
  perf c2c report: Fix crash for empty browser
  perf tests: Fix indexing when invoking subtests
  perf trace: Beautify the AF_INET &amp; AF_INET6 'socket' syscall 'protocol' args
  perf trace beauty: Add beautifiers for 'socket''s 'protocol' arg
  perf trace beauty: Do not print NULL strarray entries
  perf beauty: Add a generator for IPPROTO_ socket's protocol constants
  tools include uapi: Grab a copy of linux/in.h
  perf tests: Fix complex event name parsing
  perf evlist: Fix error out while applying initial delay and LBR
  ...
</content>
</entry>
<entry>
<title>Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2018-08-13T19:23:39Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-08-13T19:23:39Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=de5d1b39ea0b38a9f4dfb08966042b7b91e2df30'/>
<id>urn:sha1:de5d1b39ea0b38a9f4dfb08966042b7b91e2df30</id>
<content type='text'>
Pull locking/atomics update from Thomas Gleixner:
 "The locking, atomics and memory model brains delivered:

   - A larger update to the atomics code which reworks the ordering
     barriers, consolidates the atomic primitives, provides the new
     atomic64_fetch_add_unless() primitive and cleans up the include
     hell.

   - Simplify cmpxchg() instrumentation and add instrumentation for
     xchg() and cmpxchg_double().

   - Updates to the memory model and documentation"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
  locking/atomics: Rework ordering barriers
  locking/atomics: Instrument cmpxchg_double*()
  locking/atomics: Instrument xchg()
  locking/atomics: Simplify cmpxchg() instrumentation
  locking/atomics/x86: Reduce arch_cmpxchg64*() instrumentation
  tools/memory-model: Rename litmus tests to comply to norm7
  tools/memory-model/Documentation: Fix typo, smb-&gt;smp
  sched/Documentation: Update wake_up() &amp; co. memory-barrier guarantees
  locking/spinlock, sched/core: Clarify requirements for smp_mb__after_spinlock()
  sched/core: Use smp_mb() in wake_woken_function()
  tools/memory-model: Add informal LKMM documentation to MAINTAINERS
  locking/atomics/Documentation: Describe atomic_set() as a write operation
  tools/memory-model: Make scripts executable
  tools/memory-model: Remove ACCESS_ONCE() from model
  tools/memory-model: Remove ACCESS_ONCE() from recipes
  locking/memory-barriers.txt/kokr: Update Korean translation to fix broken DMA vs. MMIO ordering example
  MAINTAINERS: Add Daniel Lustig as an LKMM reviewer
  tools/memory-model: Fix ISA2+pooncelock+pooncelock+pombonce name
  tools/memory-model: Add litmus test for full multicopy atomicity
  locking/refcount: Always allow checked forms
  ...
</content>
</entry>
<entry>
<title>arc: fix build errors in arc/include/asm/delay.h</title>
<updated>2018-07-30T18:48:50Z</updated>
<author>
<name>Randy Dunlap</name>
<email>rdunlap@infradead.org</email>
</author>
<published>2018-07-27T03:16:35Z</published>
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<id>urn:sha1:2423665ec53f2a29191b35382075e9834288a975</id>
<content type='text'>
Fix build errors in arch/arc/'s delay.h:
- add "extern unsigned long loops_per_jiffy;"
- add &lt;asm-generic/types.h&gt; for "u64"

In file included from ../drivers/infiniband/hw/cxgb3/cxio_hal.c:32:
../arch/arc/include/asm/delay.h: In function '__udelay':
../arch/arc/include/asm/delay.h:61:12: error: 'u64' undeclared (first use in this function)
  loops = ((u64) usecs * 4295 * HZ * loops_per_jiffy) &gt;&gt; 32;
            ^~~

In file included from ../drivers/infiniband/hw/cxgb3/cxio_hal.c:32:
../arch/arc/include/asm/delay.h: In function '__udelay':
../arch/arc/include/asm/delay.h:63:37: error: 'loops_per_jiffy' undeclared (first use in this function)
  loops = ((u64) usecs * 4295 * HZ * loops_per_jiffy) &gt;&gt; 32;
                                     ^~~~~~~~~~~~~~~

Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: linux-snps-arc@lists.infradead.org
Cc: Elad Kanfi &lt;eladkan@mellanox.com&gt;
Cc: Leon Romanovsky &lt;leonro@mellanox.com&gt;
Cc: Ofer Levi &lt;oferle@mellanox.com&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</content>
</entry>
<entry>
<title>ARC: dma [non-IOC] setup SMP_CACHE_BYTES and cache_line_size</title>
<updated>2018-07-27T20:12:45Z</updated>
<author>
<name>Eugeniy Paltsev</name>
<email>Eugeniy.Paltsev@synopsys.com</email>
</author>
<published>2018-07-26T13:15:43Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=eb2777397fd83a4a7eaa26984d09d3babb845d2a'/>
<id>urn:sha1:eb2777397fd83a4a7eaa26984d09d3babb845d2a</id>
<content type='text'>
As for today we don't setup SMP_CACHE_BYTES and cache_line_size for
ARC, so they are set to L1_CACHE_BYTES by default. L1 line length
(L1_CACHE_BYTES) might be easily smaller than L2 line (which is
usually the case BTW). This breaks code.

For example this breaks ethernet infrastructure on HSDK/AXS103 boards
with IOC disabled, involving manual cache flushes
Functions which alloc and manage sk_buff packet data area rely on
SMP_CACHE_BYTES define. In the result we can share last L2 cache
line in sk_buff linear packet data area between DMA buffer and
some useful data in other structure. So we can lose this data when
we invalidate DMA buffer.

   sk_buff linear packet data area
                |
                |
                |         skb-&gt;end        skb-&gt;tail
                V            |                |
                             V                V
----------------------------------------------.
      packet data            | &lt;tail padding&gt; |  &lt;useful data in other struct&gt;
----------------------------------------------.

---------------------.--------------------------------------------------.
     SLC line        |             SLC (L2 cache) line (128B)           |
---------------------.--------------------------------------------------.
        ^                                     ^
        |                                     |
     These cache lines will be invalidated when we invalidate skb
     linear packet data area before DMA transaction starting.

This leads to issues painful to debug as it reproduces only if
(sk_buff-&gt;end - sk_buff-&gt;tail) &lt; SLC_LINE_SIZE and
if we have some useful data right after sk_buff-&gt;end.

Fix that by hardcode SMP_CACHE_BYTES to max line length we may have.

Signed-off-by: Eugeniy Paltsev &lt;Eugeniy.Paltsev@synopsys.com&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</content>
</entry>
<entry>
<title>Merge branch 'perf/urgent' into perf/core, to pick up fixes</title>
<updated>2018-07-25T09:47:02Z</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2018-07-25T09:47:02Z</published>
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<id>urn:sha1:93081caaaed6a40a4f6d9b7ba3f581a4bb1d4404</id>
<content type='text'>
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
</feed>
