<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/arc/include, branch v4.19.78</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>ARC: fix build warnings</title>
<updated>2019-06-25T03:35:55+00:00</updated>
<author>
<name>Vineet Gupta</name>
<email>vgupta@synopsys.com</email>
</author>
<published>2019-05-07T17:45:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4c21b761b40e082c6630f684e23c45bfbd5ef254'/>
<id>4c21b761b40e082c6630f684e23c45bfbd5ef254</id>
<content type='text'>
[ Upstream commit 89c92142f75eb80064f5b9f1111484b1b4d81790 ]

| arch/arc/mm/tlb.c:914:2: warning: variable length array 'pd0' is used [-Wvla]
| arch/arc/include/asm/cmpxchg.h:95:29: warning: value computed is not used [-Wunused-value]

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 89c92142f75eb80064f5b9f1111484b1b4d81790 ]

| arch/arc/mm/tlb.c:914:2: warning: variable length array 'pd0' is used [-Wvla]
| arch/arc/include/asm/cmpxchg.h:95:29: warning: value computed is not used [-Wunused-value]

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARCv2: don't assume core 0x54 has dual issue</title>
<updated>2019-03-23T19:09:51+00:00</updated>
<author>
<name>Vineet Gupta</name>
<email>vgupta@synopsys.com</email>
</author>
<published>2019-02-21T21:44:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8b9187e7df64541571f06388af92f769dc207bdf'/>
<id>8b9187e7df64541571f06388af92f769dc207bdf</id>
<content type='text'>
[ Upstream commit 7b2e932f633bcb7b190fc7031ce6dac75f8c3472 ]

The first release of core4 (0x54) was dual issue only (HS4x).
Newer releases allow hardware to be configured as single issue (HS3x)
or dual issue.

Prevent accessing a HS4x only aux register in HS3x, which otherwise
leads to illegal instruction exceptions

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7b2e932f633bcb7b190fc7031ce6dac75f8c3472 ]

The first release of core4 (0x54) was dual issue only (HS4x).
Newer releases allow hardware to be configured as single issue (HS3x)
or dual issue.

Prevent accessing a HS4x only aux register in HS3x, which otherwise
leads to illegal instruction exceptions

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARCv2: support manual regfile save on interrupts</title>
<updated>2019-03-23T19:09:51+00:00</updated>
<author>
<name>Vineet Gupta</name>
<email>vgupta@synopsys.com</email>
</author>
<published>2018-06-06T17:20:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3220aa9b00650b1bffa71321044518ceb303f405'/>
<id>3220aa9b00650b1bffa71321044518ceb303f405</id>
<content type='text'>
[ Upstream commit e494239a007e601448110ac304fe055951f9de3b ]

There's a hardware bug which affects the HSDK platform, triggered by
micro-ops for auto-saving regfile on taken interrupt. The workaround is
to inhibit autosave.

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit e494239a007e601448110ac304fe055951f9de3b ]

There's a hardware bug which affects the HSDK platform, triggered by
micro-ops for auto-saving regfile on taken interrupt. The workaround is
to inhibit autosave.

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARC: uacces: remove lp_start, lp_end from clobber list</title>
<updated>2019-03-23T19:09:51+00:00</updated>
<author>
<name>Vineet Gupta</name>
<email>vgupta@synopsys.com</email>
</author>
<published>2019-02-05T18:07:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=74b4dcea67568ae55996814049a7bf2ffb8ff9fb'/>
<id>74b4dcea67568ae55996814049a7bf2ffb8ff9fb</id>
<content type='text'>
[ Upstream commit d5e3c55e01d8b1774b37b4647c30fb22f1d39077 ]

Newer ARC gcc handles lp_start, lp_end in a different way and doesn't
like them in the clobber list.

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit d5e3c55e01d8b1774b37b4647c30fb22f1d39077 ]

Newer ARC gcc handles lp_start, lp_end in a different way and doesn't
like them in the clobber list.

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARC: fix __ffs return value to avoid build warnings</title>
<updated>2019-03-05T16:58:48+00:00</updated>
<author>
<name>Eugeniy Paltsev</name>
<email>Eugeniy.Paltsev@synopsys.com</email>
</author>
<published>2018-12-13T15:42:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4e34dd37943db2d546e248638a09e04d17471e40'/>
<id>4e34dd37943db2d546e248638a09e04d17471e40</id>
<content type='text'>
[ Upstream commit 4e868f8419cb4cb558c5d428e7ab5629cef864c7 ]

|  CC      mm/nobootmem.o
|In file included from ./include/asm-generic/bug.h:18:0,
|                 from ./arch/arc/include/asm/bug.h:32,
|                 from ./include/linux/bug.h:5,
|                 from ./include/linux/mmdebug.h:5,
|                 from ./include/linux/gfp.h:5,
|                 from ./include/linux/slab.h:15,
|                 from mm/nobootmem.c:14:
|mm/nobootmem.c: In function '__free_pages_memory':
|./include/linux/kernel.h:845:29: warning: comparison of distinct pointer types lacks a cast
|   (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
|                             ^
|./include/linux/kernel.h:859:4: note: in expansion of macro '__typecheck'
|   (__typecheck(x, y) &amp;&amp; __no_side_effects(x, y))
|    ^~~~~~~~~~~
|./include/linux/kernel.h:869:24: note: in expansion of macro '__safe_cmp'
|  __builtin_choose_expr(__safe_cmp(x, y), \
|                        ^~~~~~~~~~
|./include/linux/kernel.h:878:19: note: in expansion of macro '__careful_cmp'
| #define min(x, y) __careful_cmp(x, y, &lt;)
|                   ^~~~~~~~~~~~~
|mm/nobootmem.c:104:11: note: in expansion of macro 'min'
|   order = min(MAX_ORDER - 1UL, __ffs(start));

Change __ffs return value from 'int' to 'unsigned long' as it
is done in other implementations (like asm-generic, x86, etc...)
to avoid build-time warnings in places where type is strictly
checked.

As __ffs may return values in [0-31] interval changing return
type to unsigned is valid.

Signed-off-by: Eugeniy Paltsev &lt;Eugeniy.Paltsev@synopsys.com&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 4e868f8419cb4cb558c5d428e7ab5629cef864c7 ]

|  CC      mm/nobootmem.o
|In file included from ./include/asm-generic/bug.h:18:0,
|                 from ./arch/arc/include/asm/bug.h:32,
|                 from ./include/linux/bug.h:5,
|                 from ./include/linux/mmdebug.h:5,
|                 from ./include/linux/gfp.h:5,
|                 from ./include/linux/slab.h:15,
|                 from mm/nobootmem.c:14:
|mm/nobootmem.c: In function '__free_pages_memory':
|./include/linux/kernel.h:845:29: warning: comparison of distinct pointer types lacks a cast
|   (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
|                             ^
|./include/linux/kernel.h:859:4: note: in expansion of macro '__typecheck'
|   (__typecheck(x, y) &amp;&amp; __no_side_effects(x, y))
|    ^~~~~~~~~~~
|./include/linux/kernel.h:869:24: note: in expansion of macro '__safe_cmp'
|  __builtin_choose_expr(__safe_cmp(x, y), \
|                        ^~~~~~~~~~
|./include/linux/kernel.h:878:19: note: in expansion of macro '__careful_cmp'
| #define min(x, y) __careful_cmp(x, y, &lt;)
|                   ^~~~~~~~~~~~~
|mm/nobootmem.c:104:11: note: in expansion of macro 'min'
|   order = min(MAX_ORDER - 1UL, __ffs(start));

Change __ffs return value from 'int' to 'unsigned long' as it
is done in other implementations (like asm-generic, x86, etc...)
to avoid build-time warnings in places where type is strictly
checked.

As __ffs may return values in [0-31] interval changing return
type to unsigned is valid.

Signed-off-by: Eugeniy Paltsev &lt;Eugeniy.Paltsev@synopsys.com&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARC: define ARCH_SLAB_MINALIGN = 8</title>
<updated>2019-02-27T09:09:00+00:00</updated>
<author>
<name>Alexey Brodkin</name>
<email>abrodkin@synopsys.com</email>
</author>
<published>2019-02-08T10:55:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=95aed87b9e2ed982b24122f46ca506cd8b368677'/>
<id>95aed87b9e2ed982b24122f46ca506cd8b368677</id>
<content type='text'>
commit b6835ea77729e7faf4656ca637ba53f42b8ee3fd upstream.

The default value of ARCH_SLAB_MINALIGN in "include/linux/slab.h" is
"__alignof__(unsigned long long)" which for ARC unexpectedly turns out
to be 4. This is not a compiler bug, but as defined by ARC ABI [1]

Thus slab allocator would allocate a struct which is 32-bit aligned,
which is generally OK even if struct has long long members.
There was however potetial problem when it had any atomic64_t which
use LLOCKD/SCONDD instructions which are required by ISA to take
64-bit addresses. This is the problem we ran into

[    4.015732] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)
[    4.167881] Misaligned Access
[    4.172356] Path: /bin/busybox.nosuid
[    4.176004] CPU: 2 PID: 171 Comm: rm Not tainted 4.19.14-yocto-standard #1
[    4.182851]
[    4.182851] [ECR   ]: 0x000d0000 =&gt; Check Programmer's Manual
[    4.190061] [EFA   ]: 0xbeaec3fc
[    4.190061] [BLINK ]: ext4_delete_entry+0x210/0x234
[    4.190061] [ERET  ]: ext4_delete_entry+0x13e/0x234
[    4.202985] [STAT32]: 0x80080002 : IE K
[    4.207236] BTA: 0x9009329c   SP: 0xbe5b1ec4  FP: 0x00000000
[    4.212790] LPS: 0x9074b118  LPE: 0x9074b120 LPC: 0x00000000
[    4.218348] r00: 0x00000040  r01: 0x00000021 r02: 0x00000001
...
...
[    4.270510] Stack Trace:
[    4.274510]   ext4_delete_entry+0x13e/0x234
[    4.278695]   ext4_rmdir+0xe0/0x238
[    4.282187]   vfs_rmdir+0x50/0xf0
[    4.285492]   do_rmdir+0x9e/0x154
[    4.288802]   EV_Trap+0x110/0x114

The fix is to make sure slab allocations are 64-bit aligned.

Do note that atomic64_t is __attribute__((aligned(8)) which means gcc
does generate 64-bit aligned references, relative to beginning of
container struct. However the issue is if the container itself is not
64-bit aligned, atomic64_t ends up unaligned which is what this patch
ensures.

[1] https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/wiki/files/ARCv2_ABI.pdf

Signed-off-by: Alexey Brodkin &lt;abrodkin@synopsys.com&gt;
Cc: &lt;stable@vger.kernel.org&gt; # 4.8+
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
[vgupta: reworked changelog, added dependency on LL64+LLSC]
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b6835ea77729e7faf4656ca637ba53f42b8ee3fd upstream.

The default value of ARCH_SLAB_MINALIGN in "include/linux/slab.h" is
"__alignof__(unsigned long long)" which for ARC unexpectedly turns out
to be 4. This is not a compiler bug, but as defined by ARC ABI [1]

Thus slab allocator would allocate a struct which is 32-bit aligned,
which is generally OK even if struct has long long members.
There was however potetial problem when it had any atomic64_t which
use LLOCKD/SCONDD instructions which are required by ISA to take
64-bit addresses. This is the problem we ran into

[    4.015732] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)
[    4.167881] Misaligned Access
[    4.172356] Path: /bin/busybox.nosuid
[    4.176004] CPU: 2 PID: 171 Comm: rm Not tainted 4.19.14-yocto-standard #1
[    4.182851]
[    4.182851] [ECR   ]: 0x000d0000 =&gt; Check Programmer's Manual
[    4.190061] [EFA   ]: 0xbeaec3fc
[    4.190061] [BLINK ]: ext4_delete_entry+0x210/0x234
[    4.190061] [ERET  ]: ext4_delete_entry+0x13e/0x234
[    4.202985] [STAT32]: 0x80080002 : IE K
[    4.207236] BTA: 0x9009329c   SP: 0xbe5b1ec4  FP: 0x00000000
[    4.212790] LPS: 0x9074b118  LPE: 0x9074b120 LPC: 0x00000000
[    4.218348] r00: 0x00000040  r01: 0x00000021 r02: 0x00000001
...
...
[    4.270510] Stack Trace:
[    4.274510]   ext4_delete_entry+0x13e/0x234
[    4.278695]   ext4_rmdir+0xe0/0x238
[    4.282187]   vfs_rmdir+0x50/0xf0
[    4.285492]   do_rmdir+0x9e/0x154
[    4.288802]   EV_Trap+0x110/0x114

The fix is to make sure slab allocations are 64-bit aligned.

Do note that atomic64_t is __attribute__((aligned(8)) which means gcc
does generate 64-bit aligned references, relative to beginning of
container struct. However the issue is if the container itself is not
64-bit aligned, atomic64_t ends up unaligned which is what this patch
ensures.

[1] https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/wiki/files/ARCv2_ABI.pdf

Signed-off-by: Alexey Brodkin &lt;abrodkin@synopsys.com&gt;
Cc: &lt;stable@vger.kernel.org&gt; # 4.8+
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
[vgupta: reworked changelog, added dependency on LL64+LLSC]
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ARC: perf: map generic branches to correct hardware condition</title>
<updated>2019-01-31T07:14:35+00:00</updated>
<author>
<name>Eugeniy Paltsev</name>
<email>Eugeniy.Paltsev@synopsys.com</email>
</author>
<published>2018-12-17T09:54:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8cbca17381ac78e0e287a99fd3575114b6143345'/>
<id>8cbca17381ac78e0e287a99fd3575114b6143345</id>
<content type='text'>
commit 3affbf0e154ee351add6fcc254c59c3f3947fa8f upstream.

So far we've mapped branches to "ijmp" which also counts conditional
branches NOT taken. This makes us different from other architectures
such as ARM which seem to be counting only taken branches.

So use "ijmptak" hardware condition which only counts (all jump
instructions that are taken)

'ijmptak' event is available on both ARCompact and ARCv2 ISA based
cores.

Signed-off-by: Eugeniy Paltsev &lt;Eugeniy.Paltsev@synopsys.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
[vgupta: reworked changelog]
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 3affbf0e154ee351add6fcc254c59c3f3947fa8f upstream.

So far we've mapped branches to "ijmp" which also counts conditional
branches NOT taken. This makes us different from other architectures
such as ARM which seem to be counting only taken branches.

So use "ijmptak" hardware condition which only counts (all jump
instructions that are taken)

'ijmptak' event is available on both ARCompact and ARCv2 ISA based
cores.

Signed-off-by: Eugeniy Paltsev &lt;Eugeniy.Paltsev@synopsys.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
[vgupta: reworked changelog]
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ARC: io.h: Implement reads{x}()/writes{x}()</title>
<updated>2018-12-21T13:15:16+00:00</updated>
<author>
<name>Jose Abreu</name>
<email>joabreu@synopsys.com</email>
</author>
<published>2018-11-30T09:47:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bf69dc3cb1b8a72652ed44020678b6dbefa713fc'/>
<id>bf69dc3cb1b8a72652ed44020678b6dbefa713fc</id>
<content type='text'>
[ Upstream commit 10d443431dc2bb733cf7add99b453e3fb9047a2e ]

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;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 10d443431dc2bb733cf7add99b453e3fb9047a2e ]

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;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARC: dma [IOC] Enable per device io coherency</title>
<updated>2018-09-04T20:21:37+00:00</updated>
<author>
<name>Eugeniy Paltsev</name>
<email>Eugeniy.Paltsev@synopsys.com</email>
</author>
<published>2018-07-30T16:26:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2820a708d5a321342bef34e459fdc8679c30e20f'/>
<id>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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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]
</pre>
</div>
</content>
</entry>
<entry>
<title>ARC: atomics: unbork atomic_fetch_##op()</title>
<updated>2018-08-31T17:14:51+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2018-08-30T20:52:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3fcbb8260a87efb691d837e8cd24e81f65b3eb70'/>
<id>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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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]
</pre>
</div>
</content>
</entry>
</feed>
