Commit Graph

565 Commits

Author SHA1 Message Date
Vineet Gupta
1097163870 ARCv2: spinlock/rwlock/atomics: reduce 1 instruction in exponential backoff
The increment of delay counter was 2 instructions:
Arithmatic Shfit Left (ASL) + set to 1 on overflow

This can be done in 1 using ROtate Left (ROL)

Suggested-by: Nigel Topham <ntopham@synopsys.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-07 13:56:16 +05:30
Vineet Gupta
87ce62802f ARC: Make pt_regs regs unsigned
KGDB fails to build after f51e2f1911 ("ARC: make sure instruction_pointer()
returns unsigned value")

The hack to force one specific reg to unsigned backfired. There's no
reason to keep the regs signed after all.

|  CC      arch/arc/kernel/kgdb.o
|../arch/arc/kernel/kgdb.c: In function 'kgdb_trap':
| ../arch/arc/kernel/kgdb.c:180:29: error: lvalue required as left operand of assignment
|   instruction_pointer(regs) -= BREAK_INSTR_SIZE;

Reported-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Fixes: f51e2f1911 ("ARC: make sure instruction_pointer() returns unsigned value")
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-05 11:48:21 +05:30
Vineet Gupta
b89aa12c17 ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle
The previous commit for delayed retry of SCOND needs some fine tuning
for spin locks.

The backoff from delayed retry in conjunction with spin looping of lock
itself can potentially cause the delay counter to reach high values.
So to provide fairness to any lock operation, after a lock "seems"
available (i.e. just before first SCOND try0, reset the delay counter
back to starting value of 1

Essentially reset delay to 1 for a new spin-wait-loop-acquire cycle.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:35 +05:30
Vineet Gupta
e78fdfef84 ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff
This is to workaround the llock/scond livelock

HS38x4 could get into a LLOCK/SCOND livelock in case of multiple overlapping
coherency transactions in the SCU. The exclusive line state keeps rotating
among contenting cores leading to a never ending cycle. So break the cycle
by deferring the retry of failed exclusive access (SCOND). The actual delay
needed is function of number of contending cores as well as the unrelated
coherency traffic from other cores. To keep the code simple, start off with
small delay of 1 which would suffice most cases and in case of contention
double the delay. Eventually the delay is sufficient such that the coherency
pipeline is drained, thus a subsequent exclusive access would succeed.

Link: http://lkml.kernel.org/r/1438612568-28265-1-git-send-email-vgupta@synopsys.com
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:34 +05:30
Vineet Gupta
69cbe630f5 ARC: LLOCK/SCOND based rwlock
With LLOCK/SCOND, the rwlock counter can be atomically updated w/o need
for a guarding spin lock.

This in turn elides the EXchange instruction based spinning which causes
the cacheline transition to exclusive state and concurrent spinning
across cores would cause the line to keep bouncing around.
LLOCK/SCOND based implementation is superior as spinning on LLOCK keeps
the cacheline in shared state.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:33 +05:30
Vineet Gupta
ae7eae9e03 ARC: LLOCK/SCOND based spin_lock
Current spin_lock uses EXchange instruction to implement the atomic test
and set of lock location (reads orig value and ST 1). This however forces
the cacheline into exclusive state (because of the ST) and concurrent
loops in multiple cores will bounce the line around between cores.

Instead, use LLOCK/SCOND to implement the atomic test and set which is
better as line is in shared state while lock is spinning on LLOCK

The real motivation of this change however is to make way for future
changes in atomics to implement delayed retry (with backoff).
Initial experiment with delayed retry in atomics combined with orig
EX based spinlock was a total disaster (broke even LMBench) as
struct sock has a cache line sharing an atomic_t and spinlock. The
tight spinning on lock, caused the atomic retry to keep backing off
such that it would never finish.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:33 +05:30
Vineet Gupta
8ac0665fb6 ARC: refactor atomic inline asm operands with symbolic names
This reduces the diff in forth-coming patches and also helps understand
better the incremental changes to inline asm.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:32 +05:30
Vineet Gupta
f5959cb0c3 Revert "ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock"
Extended testing of quad core configuration revealed that this fix was
insufficient. Specifically LTP open posix shm_op/23-1 would cause the
hardware livelock in llock/scond loop in update_cpu_load_active()

So remove this and make way for a proper workaround

This reverts commit a5c8b52abe.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:31 +05:30
Vineet Gupta
6de7abfbad ARCv2: [axs103_smp] Reduce clk for Quad FPGA configs
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:30 +05:30
Vineet Gupta
e13c42ecbe ARCv2: Fix the peripheral address space detection
With HS 2.1 release, the peripheral space register no longer contains
the uncached space specifics, causing the kernel to panic early on.
So read the newer NON VOLATILE AUX register to get that info.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-03 19:34:07 +05:30
Alexey Brodkin
450ed0db01 ARCv2: allow selection of page size for MMUv4
MMUv4 also supports the configurable page size as MMUv3.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-23 12:04:39 +03:00
Vineet Gupta
262137bca7 ARCv2: lib: memset: Don't assume 64-bit load/stores
There are configurations which may not have LDD/STD

Signed-off-by: Claudiu Zissulescu <claziss@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-20 17:44:37 +03:00
Vineet Gupta
21481f2cfe ARCv2: lib: memcpy: Missing PREFETCHW
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-20 17:27:35 +03:00
Alexey Brodkin
d05a76ab4d ARCv2: add knob for DIV_REV in Kconfig
Being highly configurable core ARC HS among other features might be
configured with or without DIV_REM_OPTION (hardware divider).

That option when enabled adds following instructions: div, divu, rem, remu.

By default ARC HS38 has this option enabled. So we add here possibility
to disable usage of hardware divider by compiler.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-20 13:33:30 +03:00
Viresh Kumar
aeec6cdad6 ARC/time: Migrate to new 'set-state' interface
Migrate arc driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-20 13:30:31 +03:00
Laurent Dufour
f2abeef9fd mm: clean up per architecture MM hook header files
Commit 2ae416b142 ("mm: new mm hook framework") introduced an empty
header file (mm-arch-hooks.h) for every architecture, even those which
doesn't need to define mm hooks.

As suggested by Geert Uytterhoeven, this could be cleaned through the use
of a generic header file included via each per architecture
asm/include/Kbuild file.

The PowerPC architecture is not impacted here since this architecture has
to defined the arch_remap MM hook.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-17 16:39:53 -07:00
Vineet Gupta
624b71ee20 ARCv2: support HS38 releases
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-13 13:33:23 +05:30
Alexey Brodkin
f51e2f1911 ARC: make sure instruction_pointer() returns unsigned value
Currently instruction_pointer() returns pt_regs->ret and so return value
is of type "long", which implicitly stands for "signed long".

While that's perfectly fine when dealing with 32-bit values if return
value of instruction_pointer() gets assigned to 64-bit variable sign
extension may happen.

And at least in one real use-case it happens already.
In perf_prepare_sample() return value of perf_instruction_pointer()
(which is an alias to instruction_pointer() in case of ARC) is assigned
to (struct perf_sample_data)->ip (which type is "u64").

And what we see if instuction pointer points to user-space application
that in case of ARC lays below 0x8000_0000 "ip" gets set properly with
leading 32 zeros. But if instruction pointer points to kernel address
space that starts from 0x8000_0000 then "ip" is set with 32 leadig
"f"-s. I.e. id instruction_pointer() returns 0x8100_0000, "ip" will be
assigned with 0xffff_ffff__8100_0000. Which is obviously wrong.

In particular that issuse broke output of perf, because perf was unable
to associate addresses like 0xffff_ffff__8100_0000 with anything from
/proc/kallsyms.

That's what we used to see:
 ----------->8----------
  6.27%  ls       [unknown]                [k] 0xffffffff8046c5cc
  2.96%  ls       libuClibc-0.9.34-git.so  [.] memcpy
  2.25%  ls       libuClibc-0.9.34-git.so  [.] memset
  1.66%  ls       [unknown]                [k] 0xffffffff80666536
  1.54%  ls       libuClibc-0.9.34-git.so  [.] 0x000224d6
  1.18%  ls       libuClibc-0.9.34-git.so  [.] 0x00022472
 ----------->8----------

With that change perf output looks much better now:
 ----------->8----------
  8.21%  ls       [kernel.kallsyms]        [k] memset
  3.52%  ls       libuClibc-0.9.34-git.so  [.] memcpy
  2.11%  ls       libuClibc-0.9.34-git.so  [.] malloc
  1.88%  ls       libuClibc-0.9.34-git.so  [.] memset
  1.64%  ls       [kernel.kallsyms]        [k] _raw_spin_unlock_irqrestore
  1.41%  ls       [kernel.kallsyms]        [k] __d_lookup_rcu
 ----------->8----------

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: arc-linux-dev@synopsys.com
Cc: stable@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-13 13:33:18 +05:30
Vineet Gupta
b631788ab4 ARC: slightly refactor macros for boot logging
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09 17:36:33 +05:30
Vineet Gupta
9138d4138d ARC: Add llock/scond to futex backend
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09 17:36:33 +05:30
Joël Porquet
70d93d8941 arc:irqchip: prepare for drivers/irqchip/irqchip.h removal
The IRQCHIP_DECLARE macro migrated to 'include/linux/irqchip.h'.

See commit 91e20b5040
("irqchip: Move IRQCHIP_DECLARE macro to include/linux/irqchip.h").

This patch removes the inclusions of private header 'drivers/irqchip/irqchip.h'
and if necessary replaces them with inclusions of 'include/linux/irqchip.h'.

Signed-off-by: Joel Porquet <joel@porquet.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09 17:36:32 +05:30
Vineet Gupta
80f420842f ARC: Make ARC bitops "safer" (add anti-optimization)
ARCompact/ARCv2 ISA provide that any instructions which deals with
bitpos/count operand ASL, LSL, BSET, BCLR, BMSK .... will only consider
lower 5 bits. i.e. auto-clamp the pos to 0-31.

ARC Linux bitops exploited this fact by NOT explicitly masking out upper
bits for @nr operand in general, saving a bunch of AND/BMSK instructions
in generated code around bitops.

While this micro-optimization has worked well over years it is NOT safe
as shifting a number with a value, greater than native size is
"undefined" per "C" spec.

So as it turns outm EZChip ran into this eventually, in their massive
muti-core SMP build with 64 cpus. There was a test_bit() inside a loop
from 63 to 0 and gcc was weirdly optimizing away the first iteration
(so it was really adhering to standard by implementing undefined behaviour
vs. removing all the iterations which were phony i.e. (1 << [63..32])

| for i = 63 to 0
|    X = ( 1 << i )
|    if X == 0
|       continue

So fix the code to do the explicit masking at the expense of generating
additional instructions. Fortunately, this can be mitigated to a large
extent as gcc has SHIFT_COUNT_TRUNCATED which allows combiner to fold
masking into shift operation itself. It is currently not enabled in ARC
gcc backend, but could be done after a bit of testing.

Fixes STAR 9000866918 ("unsafe "undefined behavior" code in kernel")

Reported-by: Noam Camus <noamc@ezchip.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09 17:36:32 +05:30
Alexey Brodkin
e2fc61f384 ARCv2: [axs103] bump CPU frequency from 75 to 90 MHZ
With up-to-date FPGA builds ARC cores are supposed to correctly operate
even with 90 MHz clock (which is a target frequency for AXS103 release).

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: arc-linux-dev@synopsys.com
2015-07-09 17:36:31 +05:30
Vineet Gupta
6b12ec177c ARCv2: intc: IDU: Fix potential race in installing a chained IRQ handler
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:06 +05:30
Vineet Gupta
83ce3e6fcc ARCv2: intc: IDU: support irq affinity
With this nsim standlone / OSCI have working irq affinity - AXS103 still
needs some work as IDU is not visible in intc hierarchy yet !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:02 +05:30
Vineet Gupta
bccea41ec0 ARC: fix unused var wanring
Fixes: 9bf39ab2ad ("vfs: add file_path() helper")
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:01 +05:30
Vineet Gupta
f718c2efff ARC: Don't memzero twice in dma_alloc_coherent for __GFP_ZERO
alloc_pages_exact() get gfp flags and handle zero'ing already

And while it, fix the case where ioremap fails: return rightaway.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:01 +05:30
Vineet Gupta
9770906921 ARC: Override toplevel default -O2 with -O3
ARC kernels have historically been built with -O3, despite top level
Makefile defaulting to -O2. This was facilitated by implicitly ordering
of arch makefile include AFTER top level assigned -O2.

An upstream fix to top level a1c48bb160 ("Makefile: Fix unrecognized
cross-compiler command line options") changed the ordering, making ARC
-O3 defunct.

Fix that by NOT relying on any ordering whatsoever and use the proper
arch override facility now present in kbuild (ARCH_*FLAGS)

Depends-on: ("kbuild: Allow arch Makefiles to override {cpp,ld,c}flags")
Suggested-by: Michal Marek <mmarek@suse.cz>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:00 +05:30
Alexey Brodkin
b607eddd71 ARCv2: guard SLC DMA ops with spinlock
SLC maintenance ops need to be serialized by software as there is no
inherent buffering / quequing of aux commands. It can silently ignore a
new aux operation if previous one is still ongoing (SLC_CTRL_BUSY)

So gaurd the SLC op using a spin lock

The spin lock doesn't seem to be contended even in heavy workloads such
as iperf. On FPGA @ 75 MHz.

 [1] Before this change:
 ============================================================
  # iperf -c 10.42.0.1
 ------------------------------------------------------------
 Client connecting to 10.42.0.1, TCP port 5001
 TCP window size: 43.8 KByte (default)
 ------------------------------------------------------------
 [  3] local 10.42.0.110 port 38935 connected with 10.42.0.1 port 5001
 [ ID] Interval       Transfer     Bandwidth
 [  3]  0.0-10.0 sec  48.4 MBytes  40.6 Mbits/sec
 ============================================================

 [2] After this change:
 ============================================================
 # iperf -c 10.42.0.1
 ------------------------------------------------------------
 Client connecting to 10.42.0.1, TCP port 5001
 TCP window size: 43.8 KByte (default)
 ------------------------------------------------------------
 [  3] local 10.42.0.243 port 60248 connected with 10.42.0.1 port 5001
 [ ID] Interval       Transfer     Bandwidth
 [  3]  0.0-10.0 sec  47.5 MBytes  39.8 Mbits/sec
 # iperf -c 10.42.0.1
 ------------------------------------------------------------
 Client connecting to 10.42.0.1, TCP port 5001
 TCP window size: 43.8 KByte (default)
 ------------------------------------------------------------
 [  3] local 10.42.0.243 port 60249 connected with 10.42.0.1 port 5001
 [ ID] Interval       Transfer     Bandwidth
 [  3]  0.0-10.0 sec  54.9 MBytes  46.0 Mbits/sec
 ============================================================

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: arc-linux-dev@synopsys.com
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 10:12:39 +05:30
Vineet Gupta
14a0abfc4a ARC: Kconfig: better way to disable ARC_HAS_LLSC for ARC_CPU_750D
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 10:12:39 +05:30
Linus Torvalds
1dc51b8288 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...
2015-07-04 19:36:06 -07:00
Linus Torvalds
2d01eedf1d Merge branch 'akpm' (patches from Andrew)
Merge third patchbomb from Andrew Morton:

 - the rest of MM

 - scripts/gdb updates

 - ipc/ updates

 - lib/ updates

 - MAINTAINERS updates

 - various other misc things

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (67 commits)
  genalloc: rename of_get_named_gen_pool() to of_gen_pool_get()
  genalloc: rename dev_get_gen_pool() to gen_pool_get()
  x86: opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit
  MAINTAINERS: add zpool
  MAINTAINERS: BCACHE: Kent Overstreet has changed email address
  MAINTAINERS: move Jens Osterkamp to CREDITS
  MAINTAINERS: remove unused nbd.h pattern
  MAINTAINERS: update brcm gpio filename pattern
  MAINTAINERS: update brcm dts pattern
  MAINTAINERS: update sound soc intel patterns
  MAINTAINERS: remove website for paride
  MAINTAINERS: update Emulex ocrdma email addresses
  bcache: use kvfree() in various places
  libcxgbi: use kvfree() in cxgbi_free_big_mem()
  target: use kvfree() in session alloc and free
  IB/ehca: use kvfree() in ipz_queue_{cd}tor()
  drm/nouveau/gem: use kvfree() in u_free()
  drm: use kvfree() in drm_free_large()
  cxgb4: use kvfree() in t4_free_mem()
  cxgb3: use kvfree() in cxgb_free_mem()
  ...
2015-07-01 17:47:51 -07:00
Linus Torvalds
0890a26479 - Support for HS38 cores based on ARCv2 ISA
ARCv2 is the next generation ISA from Synopsys and basis for the
      HS3{4,6,8} families of processors which retain the traditional ARC mantra of
      low power and configurability and are now more performant and feature rich.
 
      HS38x is a 10 stage pipeline core which supports MMU (with huge pages) and
      SMP (upto 4 cores) among other features.
 
      + www.synopsys.com/dw/ipdir.php?ds=arc-hs38-processor
      + http://news.synopsys.com/2014-10-14-New-DesignWare-ARC-HS38-Processor-Doubles-Performance-for-Embedded-Linux-Applications
      + http://www.embedded.com/electronics-news/4435975/Synopsys-ARC-HS38-core-gives-2X-boost-to-Linux-based-apps
 
  - Support for ARC SDP (Software Development platform): Main Board + CPU Cards
     = AXS101: CPU Card with ARC700 in silicon @ 700 MHz
     = AXS103: CPU Card with HS38x in FPGA
 
  - Refactoring of ARCompact port to accomodate new ARCv2 ISA
  - Miscll updates/cleanups
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Merge tag 'arc-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC architecture updates from Vineet Gupta:

 - support for HS38 cores based on ARCv2 ISA

     ARCv2 is the next generation ISA from Synopsys and basis for the
     HS3{4,6,8} families of processors which retain the traditional ARC mantra of
     low power and configurability and are now more performant and feature rich.

     HS38x is a 10 stage pipeline core which supports MMU (with huge pages) and
     SMP (upto 4 cores) among other features.

     + www.synopsys.com/dw/ipdir.php?ds=arc-hs38-processor
     + http://news.synopsys.com/2014-10-14-New-DesignWare-ARC-HS38-Processor-Doubles-Performance-for-Embedded-Linux-Applications
     + http://www.embedded.com/electronics-news/4435975/Synopsys-ARC-HS38-core-gives-2X-boost-to-Linux-based-apps

 - support for ARC SDP (Software Development platform): Main Board + CPU Cards
    = AXS101: CPU Card with ARC700 in silicon @ 700 MHz
    = AXS103: CPU Card with HS38x in FPGA

 - refactoring of ARCompact port to accomodate new ARCv2 ISA

 - misc updates/cleanups

* tag 'arc-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (72 commits)
  ARC: Fix build failures for ARCompact in linux-next after ARCv2 support
  ARCv2: Allow older gcc to cope with new regime of ARCv2/ARCompact support
  ARCv2: [vdk] dts files and defconfig for HS38 VDK
  ARCv2: [axs103] Support ARC SDP FPGA platform for HS38x cores
  ARC: [axs101] Prepare for AXS103
  ARCv2: [nsim*hs*] Support simulation platforms for HS38x cores
  ARCv2: All bits in place, allow ARCv2 builds
  ARCv2: SLC: Handle explcit flush for DMA ops (w/o IO-coherency)
  ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock
  ARC: Reduce bitops lines of code using macros
  ARCv2: barriers
  arch: conditionally define smp_{mb,rmb,wmb}
  ARC: add smp barriers around atomics per Documentation/atomic_ops.txt
  ARC: add compiler barrier to LLSC based cmpxchg
  ARCv2: SMP: intc: IDU 2nd level intc for dynamic IRQ distribution
  ARCv2: SMP: clocksource: Enable Global Real Time counter
  ARCv2: SMP: ARConnect debug/robustness
  ARCv2: SMP: Support ARConnect (MCIP) for Inter-Core-Interrupts et al
  ARC: make plat_smp_ops weak to allow over-rides
  ARCv2: clocksource: Introduce 64bit local RTC counter
  ...
2015-07-01 09:24:26 -07:00
Akinobu Mita
92ed932d30 arc: use for_each_sg()
This replaces the plain loop over the sglist array with for_each_sg()
macro which consists of sg_next() function calls.  Since arc doesn't
select ARCH_HAS_SG_CHAIN, it is not necessary to use for_each_sg() in
order to loop over each sg element.  But this can help find problems with
drivers that do not properly initialize their sg tables when
CONFIG_DEBUG_SG is enabled.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30 19:44:58 -07:00
Vineet Gupta
40b8ad8f76 ARC: Fix build failures for ARCompact in linux-next after ARCv2 support
Reported-by: Guenter Roeck <private@roeck-us.net>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-28 20:30:13 +05:30
Vineet Gupta
d1c6c2fbcd ARCv2: Allow older gcc to cope with new regime of ARCv2/ARCompact support
-no-ll64 is specific to ARCv2 ISA, and is obviously not supported by
older ARC gcc - in this case the one hosted by linux-next sanity build
service.

Ensure that it doesn't get included for ISA_ARCOMPACT

Reported-by: Guenter Roeck <private@roeck-us.net>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-28 19:47:22 +05:30
Linus Torvalds
ad90fb9751 Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block
Pull asm/scatterlist.h removal from Jens Axboe:
 "We don't have any specific arch scatterlist anymore, since parisc
  finally switched over.  Kill the include"

* 'for-4.2/sg' of git://git.kernel.dk/linux-block:
  remove scatterlist.h generation from arch Kbuild files
  remove <asm/scatterlist.h>
2015-06-25 15:22:36 -07:00
Laurent Dufour
2ae416b142 mm: new mm hook framework
CRIU is recreating the process memory layout by remapping the checkpointee
memory area on top of the current process (criu).  This includes remapping
the vDSO to the place it has at checkpoint time.

However some architectures like powerpc are keeping a reference to the
vDSO base address to build the signal return stack frame by calling the
vDSO sigreturn service.  So once the vDSO has been moved, this reference
is no more valid and the signal frame built later are not usable.

This patch serie is introducing a new mm hook framework, and a new
arch_remap hook which is called when mremap is done and the mm lock still
hold.  The next patch is adding the vDSO remap and unmap tracking to the
powerpc architecture.

This patch (of 3):

This patch introduces a new set of header file to manage mm hooks:
- per architecture empty header file (arch/x/include/asm/mm-arch-hooks.h)
- a generic header (include/linux/mm-arch-hooks.h)

The architecture which need to overwrite a hook as to redefine it in its
header file, while architecture which doesn't need have nothing to do.

The default hooks are defined in the generic header and are used in the
case the architecture is not defining it.

In a next step, mm hooks defined in include/asm-generic/mm_hooks.h should
be moved here.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-24 17:49:41 -07:00
Ruud Derwig
2924cd18c4 ARCv2: [vdk] dts files and defconfig for HS38 VDK
- CONFIG_ARC_UBOOT_SUPPORT to handle arguments passed in r0, r1, r2
 - CONFIG_DEVTMPFS_MOUNT for mouting rootfs since it uses external cpio
   for rootfs

Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Ruud Derwig <rderwig@synopsys.com>
[vgupta: folded the Main baord DT files for smp/up into one]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:21 +05:30
Vineet Gupta
5fa2daaa8d ARCv2: [axs103] Support ARC SDP FPGA platform for HS38x cores
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:20 +05:30
Alexey Brodkin
e0183f5230 ARC: [axs101] Prepare for AXS103
To avoid duplicating the MB DTS file, move the MB intc entry into cpu
card specific file

Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:20 +05:30
Vineet Gupta
a12ebe16a5 ARCv2: [nsim*hs*] Support simulation platforms for HS38x cores
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:19 +05:30
Vineet Gupta
65bfbcdfde ARCv2: All bits in place, allow ARCv2 builds
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:19 +05:30
Vineet Gupta
795f455856 ARCv2: SLC: Handle explcit flush for DMA ops (w/o IO-coherency)
L2 cache on ARCHS processors is called SLC (System Level Cache)
For working DMA (in absence of hardware assisted IO Coherency) we need
to manage SLC explicitly when buffers transition between cpu and
controllers.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:19 +05:30
Vineet Gupta
a5c8b52abe ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock
A quad core SMP build could get into hardware livelock with concurrent
LLOCK/SCOND. Workaround that by adding a PREFETCHW which is serialized by
SCU (System Coherency Unit). It brings the cache line in Exclusive state
and makes others invalidate their lines. This gives enough time for
winner to complete the LLOCK/SCOND, before others can get the line back.

The prefetchw in the ll/sc loop is not nice but this is the only
software workaround for current version of RTL.

Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:18 +05:30
Vineet Gupta
04e2eee4b0 ARC: Reduce bitops lines of code using macros
No semantical changes !

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:18 +05:30
Vineet Gupta
b8a0330239 ARCv2: barriers
ARCv2 based HS38 cores are weakly ordered and thus explicit barriers for
kernel proper.

SMP barrier is provided by DMB instruction which also guarantees local
barrier hence used as backend of smp_*mb() as well as *mb() APIs

Also hookup barriers into MMIO accessors to avoid ordering issues in IO

Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:17 +05:30
Vineet Gupta
2576c28e3f ARC: add smp barriers around atomics per Documentation/atomic_ops.txt
- arch_spin_lock/unlock were lacking the ACQUIRE/RELEASE barriers
   Since ARCv2 only provides load/load, store/store and all/all, we need
   the full barrier

 - LLOCK/SCOND based atomics, bitops, cmpxchg, which return modified
   values were lacking the explicit smp barriers.

 - Non LLOCK/SCOND varaints don't need the explicit barriers since that
   is implicity provided by the spin locks used to implement the
   critical section (the spin lock barriers in turn are also fixed in
   this commit as explained above

Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:16 +05:30
Vineet Gupta
d57f727264 ARC: add compiler barrier to LLSC based cmpxchg
When auditing cmpxchg call sites, Chuck noted that gcc was optimizing
away some of the desired LDs.

|	do {
|		new = old = *ipi_data_ptr;
|		new |= 1U << msg;
|	} while (cmpxchg(ipi_data_ptr, old, new) != old);

was generating to below

| 8015cef8:	ld         r2,[r4,0]  <-- First LD
| 8015cefc:	bset       r1,r2,r1
|
| 8015cf00:	llock      r3,[r4]  <-- atomic op
| 8015cf04:	brne       r3,r2,8015cf10
| 8015cf08:	scond      r1,[r4]
| 8015cf0c:	bnz        8015cf00
|
| 8015cf10:	brne       r3,r2,8015cf00  <-- Branch doesn't go to orig LD

Although this was fixed by adding a ACCESS_ONCE in this call site, it
seems safer (for now at least) to add compiler barrier to LLSC based
cmpxchg

Reported-by: Chuck Jordan <cjordan@synopsys,com>
Cc: <stable@vger.kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 05:59:23 +05:30
Miklos Szeredi
9bf39ab2ad vfs: add file_path() helper
Turn
	d_path(&file->f_path, ...);
into
	file_path(file, ...);

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:00:05 -04:00