pm24.git/arch/arc/include, branch v4.2-rc3

mm: clean up per architecture MM hook header files

2015-07-17T23:39:53Z

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 Suggested-by: Geert Uytterhoeven Acked-by: Geert Uytterhoeven Acked-by: Vineet Gupta Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ARC: make sure instruction_pointer() returns unsigned value

2015-07-13T08:03:18Z

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 Cc: arc-linux-dev@synopsys.com Cc: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Vineet Gupta

ARC: Add llock/scond to futex backend

2015-07-09T12:06:33Z

Signed-off-by: Vineet Gupta

ARC: Make ARC bitops "safer" (add anti-optimization)

2015-07-09T12:06:32Z

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 Cc: Signed-off-by: Vineet Gupta

Merge branch 'akpm' (patches from Andrew)

2015-07-02T00:47:51Z

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 : (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() ...

Merge tag 'arc-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

2015-07-01T16:24:26Z

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 ...

arc: use for_each_sg()

2015-07-01T02:44:58Z

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 Acked-by: Vineet Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block

2015-06-25T22:22:36Z

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

mm: new mm hook framework

2015-06-25T00:49:41Z

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 Suggested-by: Andrew Morton Cc: "Kirill A. Shutemov" Cc: Hugh Dickins Cc: Rik van Riel Cc: Mel Gorman Cc: Pavel Emelyanov Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ARCv2: SLC: Handle explcit flush for DMA ops (w/o IO-coherency)

2015-06-25T00:30:19Z

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