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2015-08-07ARCv2: spinlock/rwlock/atomics: reduce 1 instruction in exponential backoffVineet Gupta
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>
2015-08-05ARC: Make pt_regs regs unsignedVineet Gupta
KGDB fails to build after f51e2f191112 ("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: f51e2f191112 ("ARC: make sure instruction_pointer() returns unsigned value") Cc: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycleVineet Gupta
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>
2015-08-04ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with ↵Vineet Gupta
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>
2015-08-04ARC: LLOCK/SCOND based rwlockVineet Gupta
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>
2015-08-04ARC: LLOCK/SCOND based spin_lockVineet Gupta
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>
2015-08-04ARC: refactor atomic inline asm operands with symbolic namesVineet Gupta
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>
2015-08-04Revert "ARCv2: STAR 9000837815 workaround hardware exclusive transactions ↵Vineet Gupta
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 a5c8b52abe677977883655166796f167ef1e0084. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04ARCv2: [axs103_smp] Reduce clk for Quad FPGA configsVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-03ARCv2: Fix the peripheral address space detectionVineet Gupta
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>
2015-07-23ARCv2: allow selection of page size for MMUv4Alexey Brodkin
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>
2015-07-20ARCv2: lib: memset: Don't assume 64-bit load/storesVineet Gupta
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>
2015-07-20ARCv2: lib: memcpy: Missing PREFETCHWVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-20ARCv2: add knob for DIV_REV in KconfigAlexey Brodkin
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>
2015-07-20ARC/time: Migrate to new 'set-state' interfaceViresh Kumar
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>
2015-07-17mm: clean up per architecture MM hook header filesLaurent Dufour
Commit 2ae416b142b6 ("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>
2015-07-13ARCv2: support HS38 releasesVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-13ARC: make sure instruction_pointer() returns unsigned valueAlexey Brodkin
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>
2015-07-09ARC: slightly refactor macros for boot loggingVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09ARC: Add llock/scond to futex backendVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09arc:irqchip: prepare for drivers/irqchip/irqchip.h removalJoël Porquet
The IRQCHIP_DECLARE macro migrated to 'include/linux/irqchip.h'. See commit 91e20b5040c67c51aad88cf87db4305c5bd7f79d ("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>
2015-07-09ARC: Make ARC bitops "safer" (add anti-optimization)Vineet Gupta
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>
2015-07-09ARCv2: [axs103] bump CPU frequency from 75 to 90 MHZAlexey Brodkin
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
2015-07-06ARCv2: intc: IDU: Fix potential race in installing a chained IRQ handlerVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06ARCv2: intc: IDU: support irq affinityVineet Gupta
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>
2015-07-06ARC: fix unused var wanringVineet Gupta
Fixes: 9bf39ab2adaf ("vfs: add file_path() helper") Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06ARC: Don't memzero twice in dma_alloc_coherent for __GFP_ZEROVineet Gupta
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>
2015-07-06ARC: Override toplevel default -O2 with -O3Vineet Gupta
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 a1c48bb160f ("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>
2015-07-06ARCv2: guard SLC DMA ops with spinlockAlexey Brodkin
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>
2015-07-06ARC: Kconfig: better way to disable ARC_HAS_LLSC for ARC_CPU_750DVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-05Merge branch 'for-linus' of ↵Linus Torvalds
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 ...
2015-07-02Merge branch 'akpm' (patches from Andrew)Linus Torvalds
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() ...
2015-07-01Merge tag 'arc-4.2-rc1' of ↵Linus Torvalds
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 ...
2015-07-01arc: use for_each_sg()Akinobu Mita
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>
2015-06-28ARC: Fix build failures for ARCompact in linux-next after ARCv2 supportVineet Gupta
Reported-by: Guenter Roeck <private@roeck-us.net> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-28ARCv2: Allow older gcc to cope with new regime of ARCv2/ARCompact supportVineet Gupta
-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>
2015-06-25Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-blockLinus Torvalds
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>
2015-06-25mm: new mm hook frameworkLaurent Dufour
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>
2015-06-25ARCv2: [vdk] dts files and defconfig for HS38 VDKRuud Derwig
- 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>
2015-06-25ARCv2: [axs103] Support ARC SDP FPGA platform for HS38x coresVineet Gupta
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>
2015-06-25ARC: [axs101] Prepare for AXS103Alexey Brodkin
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>
2015-06-25ARCv2: [nsim*hs*] Support simulation platforms for HS38x coresVineet Gupta
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>
2015-06-25ARCv2: All bits in place, allow ARCv2 buildsVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25ARCv2: SLC: Handle explcit flush for DMA ops (w/o IO-coherency)Vineet Gupta
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>
2015-06-25ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelockVineet Gupta
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>
2015-06-25ARC: Reduce bitops lines of code using macrosVineet Gupta
No semantical changes ! Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25ARCv2: barriersVineet Gupta
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>
2015-06-25ARC: add smp barriers around atomics per Documentation/atomic_ops.txtVineet Gupta
- 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>
2015-06-25ARC: add compiler barrier to LLSC based cmpxchgVineet Gupta
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>
2015-06-23vfs: add file_path() helperMiklos Szeredi
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>