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* dma-mapping: always provide the dma_map_ops based implementationChristoph Hellwig2016-01-201-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the generic implementation to <linux/dma-mapping.h> now that all architectures support it and remove the HAVE_DMA_ATTR Kconfig symbol now that everyone supports them. [valentinrothberg@gmail.com: remove leftovers in Kconfig] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Helge Deller <deller@gmx.de> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Steven Miao <realmz6@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arc: convert to dma_map_opsChristoph Hellwig2016-01-201-183/+4
| | | | | | | | | | | | | [vgupta@synopsys.com: ARC: dma mapping fixes #2] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Carlos Palminha <CARLOS.PALMINHA@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ARC: mm: fix building for MMU v2Alexey Brodkin2015-12-211-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | ARC700 cores with MMU v2 don't have IC_PTAG AUX register and so we only define ARC_REG_IC_PTAG for MMU versions >= 3. But current implementation of cache_line_loop_vX() routines assumes availability of all of them (v2, v3 and v4) simultaneously. And given undefined ARC_REG_IC_PTAG if CONFIG_MMU_VER=2 we're seeing compilation problem: ---------------------------------->8------------------------------- CC arch/arc/mm/cache.o arch/arc/mm/cache.c: In function '__cache_line_loop_v3': arch/arc/mm/cache.c:270:13: error: 'ARC_REG_IC_PTAG' undeclared (first use in this function) aux_tag = ARC_REG_IC_PTAG; ^ arch/arc/mm/cache.c:270:13: note: each undeclared identifier is reported only once for each function it appears in scripts/Makefile.build:258: recipe for target 'arch/arc/mm/cache.o' failed ---------------------------------->8------------------------------- The simples fix is to have ARC_REG_IC_PTAG defined regardless MMU version being used. We don't use it in cache_line_loop_v2() anyways so who cares. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: smp: Rename platform hook @init_cpu_smp -> @init_per_cpuVineet Gupta2015-12-171-2/+2
| | | | | | Makes it similar to smp_ops which also has callback with same name Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: rename smp operation init_irq_cpu() to init_per_cpu()Noam Camus2015-12-171-2/+2
| | | | | | | | | This will better reflect its description i.e. "any needed setup..." and not just do an "IPI request". Signed-off-by: Noam Camus <noamc@ezchip.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: dw2 unwind: Reinstante unwinding out of modulesVineet Gupta2015-12-171-4/+0
| | | | | | | | | | | | | | | | | The fix which removed linear searching of dwarf (because binary lookup data always exists) missed out on the fact that modules don't get the binary lookup tables info. This caused unwinding out of modules to stop working. So add binary lookup header setup (equivalent of eh_frame_hdr setup) to modules as well. While at it, confine the header setup to within unwinder code, reducing one API exposed out of unwinder code. Fixes: 2e22502c080f ARC: dw2 unwind: Remove falllback linear search thru FDE entries Cc: <stable@vger.kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARCv2: Use the default irq priority for idle sleepVineet Gupta2015-11-161-1/+2
| | | | | | | | | | | | | | Although kernel doesn't support the multiple IRQ priority levels provided by HS38x core intc yet, ensure that the default prio value is used anyways by relevant code. SLEEP insn needs to be provided the IRQ priority level which can interrupt it. This needs to be the default level which maynot necessarily be 0 as assumed by current code. This change allows a kernel with ARCV2_IRQ_DEF_PRIO = 1 to boot fine. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Abstract out ISA specific SLEEP argsVineet Gupta2015-11-162-0/+4
| | | | | | No semantical changes, prepares for ARCv2 specific change in next commit Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* Merge tag 'arc-4.4-rc1-part2' of ↵Linus Torvalds2015-11-141-4/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc Pull ARC fixes from Vineet Gupta: "Found a couple of brown paper bag bugs with the prev pull request (including a SMP build breakage report from Guenter). Since these are urgent I also decided to send over a bunch of other pending fixes which could have otherwise waited an rc or two. Summary: - A bunch of brown paper bag bugs (MAINTAINERS list email, SMP build failure) - cpu_relax() now compiler barrier for UP as well - handling of userspace Bus Errors for ARCompact builds" * tag 'arc-4.4-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: Fix silly typo in MAINTAINERS file ARC: cpu_relax() to be compiler barrier even for UP ARC: use ASL assembler mnemonic ARC: [arcompact] Handle bus error from userspace as Interrupt not exception ARC: remove extraneous header include ARCv2: lib: memcpy: use local symbols
| * ARC: cpu_relax() to be compiler barrier even for UPVineet Gupta2015-11-141-4/+0
| | | | | | | | | | | | | | | | | | | | cpu_relax() on ARC has been barrier only for SMP (and no-op for UP). Per recent discussions, it is safer to make it a compiler barrier unconditionally. Link: http://lkml.kernel.org/r/53A7D3AA.9020100@synopsys.com Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2015-11-031-4/+4
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking changes from Ingo Molnar: "The main changes in this cycle were: - More gradual enhancements to atomic ops: new atomic*_read_ctrl() ops, synchronize atomic_{read,set}() ordering requirements between architectures, add atomic_long_t bitops. (Peter Zijlstra) - Add _{relaxed|acquire|release}() variants for inc/dec atomics and use them in various locking primitives: mutex, rtmutex, mcs, rwsem. This enables weakly ordered architectures (such as arm64) to make use of more locking related optimizations. (Davidlohr Bueso) - Implement atomic[64]_{inc,dec}_relaxed() on ARM. (Will Deacon) - Futex kernel data cache footprint micro-optimization. (Rasmus Villemoes) - pvqspinlock runtime overhead micro-optimization. (Waiman Long) - misc smaller fixlets" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: ARM, locking/atomics: Implement _relaxed variants of atomic[64]_{inc,dec} locking/rwsem: Use acquire/release semantics locking/mcs: Use acquire/release semantics locking/rtmutex: Use acquire/release semantics locking/mutex: Use acquire/release semantics locking/asm-generic: Add _{relaxed|acquire|release}() variants for inc/dec atomics atomic: Implement atomic_read_ctrl() atomic, arch: Audit atomic_{read,set}() atomic: Add atomic_long_t bitops futex: Force hot variables into a single cache line locking/pvqspinlock: Kick the PV CPU unconditionally when _Q_SLOW_VAL locking/osq: Relax atomic semantics locking/qrwlock: Rename ->lock to ->wait_lock locking/Documentation/lockstat: Fix typo - lokcing -> locking locking/atomics, cmpxchg: Privatize the inclusion of asm/cmpxchg.h
| * Merge tag 'v4.3-rc4' into locking/core, to pick up fixes before applying new ↵Ingo Molnar2015-10-061-0/+1
| |\ | | | | | | | | | | | | | | | changes Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | atomic, arch: Audit atomic_{read,set}()Peter Zijlstra2015-09-231-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes sure that atomic_{read,set}() are at least {READ,WRITE}_ONCE(). We already had the 'requirement' that atomic_read() should use ACCESS_ONCE(), and most archs had this, but a few were lacking. All are now converted to use READ_ONCE(). And, by a symmetry and general paranoia argument, upgrade atomic_set() to use WRITE_ONCE(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: james.hogan@imgtec.com Cc: linux-kernel@vger.kernel.org Cc: oleg@redhat.com Cc: will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | ARC: mm: PAE40 supportVineet Gupta2015-10-295-4/+23
| | | | | | | | | | | | | | | | | | | | | | | | This is the first working implementation of 40-bit physical address extension on ARCv2. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: mm: PAE40: switch to using phys_addr_t for physical addressesVineet Gupta2015-10-281-4/+4
| | | | | | | | | | | | | | | | | | | | | That way a single flip of phys_addr_t to 64 bit ensures all places dealing with physical addresses get correct data Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: mm: HIGHMEM: kmap API implementationVineet Gupta2015-10-283-1/+85
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement kmap* API for ARC. This enables - permanent kernel maps (pkmaps): :kmap() API - fixmap : kmap_atomic() We use a very simple/uniform approach for both (unlike some of the other arches). So fixmap doesn't use the customary compile time address stuff. The important semantic is sleep'ability (pkmap) vs. not (fixmap) which the API guarantees. Note that this patch only enables highmem for subsequent PAE40 support as there is no real highmem for ARC in pure 32-bit paradigm as explained below. ARC has 2:2 address split of the 32-bit address space with lower half being translated (virtual) while upper half unstranslated (0x8000_0000 to 0xFFFF_FFFF). kernel itself is linked at base of unstranslated space (i.e. 0x8000_0000 onwards), which is mapped to say DDR 0x0 by external Bus Glue logic (outside the core). So kernel can potentially access 1.75G worth of memory directly w/o need for highmem. (the top 256M is taken by uncached peripheral space from 0xF000_0000 to 0xFFFF_FFFF) In PAE40, hardware can address memory beyond 4G (0x1_0000_0000) while the logical/virtual addresses remain 32-bits. Thus highmem is required for kernel proper to be able to access these pages for it's own purposes (user space is agnostic to this anyways). Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: mm: preps ahead of HIGHMEM supportVineet Gupta2015-10-281-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before we plug in highmem support, some of code needs to be ready for it - copy_user_highpage() needs to be using the kmap_atomic API - mk_pte() can't assume page_address() - do_page_fault() can't assume VMALLOC_END is end of kernel vaddr space Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: mm: use generic macros _BITUL()/_AC()Alexey Brodkin2015-10-281-7/+4
| | | | | | | | | | | | | | | Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_smp()Vineet Gupta2015-10-281-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MCIP now registers it's own per cpu setup routine (for IPI IRQ request) using smp_ops.init_irq_cpu(). So no need for platforms to do that. This now completely decouples platforms from MCIP. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: smp: Introduce smp hook @init_irq_cpu called for all coresVineet Gupta2015-10-281-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Note this is not part of platform owned static machine_desc, but more of device owned plat_smp_ops (rather misnamed) which a IPI provider or some such typically defines. This will help us seperate out the IPI registration from platform specific init_cpu_smp() into device specific init_irq_cpu() Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: smp: Rename platform hook @init_smp -> @init_cpu_smpVineet Gupta2015-10-281-2/+2
| | | | | | | | | | | | | | | | | | This conveys better that it is called for each cpu Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_early_smp()Vineet Gupta2015-10-281-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MCIP now registers it's own probe callback with smp_ops.init_early_smp() which is called by ARC common code, so no need for platforms to do that. This decouples the platforms and MCIP and helps confine MCIP details to it's own file. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: smp: Introduce smp hook @init_early_smp for Master coreVineet Gupta2015-10-281-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a platform agnostic early SMP init hook which is called on Master core before calling setup_processor() setup_arch() smp_init_cpus() smp_ops.init_early_smp() ... setup_processor() How this helps: - Used for one time init of certain SMP centric IP blocks, before calling setup_processor() which probes various bits of core, possibly including this block - Currently platforms need to call this IP block init from their init routines, which doesn't make sense as this is specific to ARC core and not platform and otherwise requires copy/paste in all (and hence a possible point of failure) e.g. MCIP init is called from 2 platforms currently (axs10x and sim) which will go away once we have this. This change only adds the hooks but they are empty for now. Next commit will populate them and remove the explicit init calls from platforms. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: remove @init_time, @init_irq platform callbacksVineet Gupta2015-10-281-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These are not in use for ARC platforms. Moreover DT mechanims exist to probe them w/o explicit platform calls. - clocksource drivers can use CLOCKSOURCE_OF_DECLARE() - intc IRQCHIP_DECLARE() calls + cascading inside DT allows external intc to be probed automatically Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: smp: irqchip: handle IPI as percpu irq like timerVineet Gupta2015-10-281-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The reason this was not done so far was lack of genuine IPI_IRQ for ARC700, as we don't have a SMP version of core yet (which might change soon thx to EZChip). Nevertheles to increase the build coverage, we need to allow CONFIG_SMP for ARC700 and still be able to run it on a UP platform (nsim or AXS101) with a UP Device Tree (SMP-on-UP) The build itself requires some define for IPI_IRQ and even a dummy value is fine since that code won't run anyways. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: boot log: decode more mmu config itemsVineet Gupta2015-10-171-1/+1
| | | | | | | | | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: boot log: move helper macros to header for reuseVineet Gupta2015-10-171-0/+7
| | | | | | | | | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: mm: compute TLB size as needed from ways * setsVineet Gupta2015-10-171-2/+2
| | | | | | | | | | | | | | | | | | | | | This frees up some bits to hold more high level info such as PAE being present, w/o increasing the size of already bloated cpuinfo struct Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: make write_aux_reg safer against macro substitutionVineet Gupta2015-10-171-1/+1
| | | | | | | | | | | | | | | | | | It was generating warnings when called as write_aux_reg(x, paddr >> 32) Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: [arcompact] entry.S: Improve early return from exceptionVineet Gupta2015-10-172-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The requirement is to - Reenable Exceptions (AE cleared) - Reenable Interrupts (E1/E2 set) We need to do wiggle these bits into ERSTATUS and call RTIE. Prev version used the pre-exception STATUS32 as starting point for what goes into ERSTATUS. This required explicit fixups of U/DE/L bits. Instead, use the current (in-exception) STATUS32 as starting point. Being in exception handler U/DE/L can be safely assumed to be correct. Only AE/E1/E2 need to be fixed. So the new implementation is slightly better -Avoids read form memory -Is 4 bytes smaller for the typical 1 level of intr configuration -Depicts the semantics more clearly Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: [arcompact] don't check for hard isr calling local_irq_enable()Vineet Gupta2015-10-171-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Historically this was done by ARC IDE driver, which is long gone. IRQ core is pretty robust now and already checks if IRQs are enabled in hard ISRs. Thus no point in checking this in arch code, for every call of irq enabled. Further if some driver does do that - let it bring down the system so we notice/fix this sooner than covering up for sucker This makes local_irq_enable() - for L1 only case atleast simple enough so we can inline it. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARCv2: mm: THP: flush_pmd_tlb_range make SMP safeVineet Gupta2015-10-171-0/+5
| | | | | | | | | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARCv2: mm: THP: Implement flush_pmd_tlb_range() optimizationVineet Gupta2015-10-171-0/+4
| | | | | | | | | | | | | | | | | | | | | Implement the TLB flush routine to evict a sepcific Super TLB entry, vs. moving to a new ASID on every such flush. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARCv2: mm: THP supportVineet Gupta2015-10-173-2/+92
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MMUv4 in HS38x cores supports Super Pages which are basis for Linux THP support. Normal and Super pages can co-exist (ofcourse not overlap) in TLB with a new bit "SZ" in TLB page desciptor to distinguish between them. Super Page size is configurable in hardware (4K to 16M), but fixed once RTL builds. The exact THP size a Linx configuration will support is a function of: - MMU page size (typical 8K, RTL fixed) - software page walker address split between PGD:PTE:PFN (typical 11:8:13, but can be changed with 1 line) So for above default, THP size supported is 8K * 256 = 2M Default Page Walker is 2 levels, PGD:PTE:PFN, which in THP regime reduces to 1 level (as PTE is folded into PGD and canonically referred to as PMD). Thus thp PMD accessors are implemented in terms of PTE (just like sparc) Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: mm: Introduce PTE_SPECIALVineet Gupta2015-10-091-2/+5
| | | | | | | | | | | | | | | | | | Needed for THP, but will also come in handy for fast GUP later Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: mm: pte flags comsetic cleanups, commentsVineet Gupta2015-10-091-21/+16
| | | | | | | | | | | | | | | | | | No semantical changes Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: mm: switch pgtable_to to pte_t *Vineet Gupta2015-10-092-5/+5
| |/ |/| | | | | | | | | | | | | | | | | | | | | ARC is the only arch with unsigned long type (vs. struct page *). Historically this was done to avoid the page_address() calls in various arch hooks which need to get the virtual/logical address of the table. Some arches alternately define it as pte_t *, and is as efficient as unsigned long (generated code doesn't change) Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | Merge branch 'strscpy' of ↵Linus Torvalds2015-10-041-0/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile Pull strscpy string copy function implementation from Chris Metcalf. Chris sent this during the merge window, but I waffled back and forth on the pull request, which is why it's going in only now. The new "strscpy()" function is definitely easier to use and more secure than either strncpy() or strlcpy(), both of which are horrible nasty interfaces that have serious and irredeemable problems. strncpy() has a useless return value, and doesn't NUL-terminate an overlong result. To make matters worse, it pads a short result with zeroes, which is a performance disaster if you have big buffers. strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking the insane NUL padding, but having a differently broken return value which returns the original length of the source string. Which means that it will read characters past the count from the source buffer, and you have to trust the source to be properly terminated. It also makes error handling fragile, since the test for overflow is unnecessarily subtle. strscpy() avoids both these problems, guaranteeing the NUL termination (but not excessive padding) if the destination size wasn't zero, and making the overflow condition very obvious by returning -E2BIG. It also doesn't read past the size of the source, and can thus be used for untrusted source data too. So why did I waffle about this for so long? Every time we introduce a new-and-improved interface, people start doing these interminable series of trivial conversion patches. And every time that happens, somebody does some silly mistake, and the conversion patch to the improved interface actually makes things worse. Because the patch is mindnumbing and trivial, nobody has the attention span to look at it carefully, and it's usually done over large swatches of source code which means that not every conversion gets tested. So I'm pulling the strscpy() support because it *is* a better interface. But I will refuse to pull mindless conversion patches. Use this in places where it makes sense, but don't do trivial patches to fix things that aren't actually known to be broken. * 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: tile: use global strscpy() rather than private copy string: provide strscpy() Make asm/word-at-a-time.h available on all architectures
| * Make asm/word-at-a-time.h available on all architecturesChris Metcalf2015-07-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Added the x86 implementation of word-at-a-time to the generic version, which previously only supported big-endian. Omitted the x86-specific load_unaligned_zeropad(), which in any case is also not present for the existing BE-only implementation of a word-at-a-time, and is only used under CONFIG_DCACHE_WORD_ACCESS. Added as a "generic-y" to the Kbuilds of all architectures that didn't previously have it. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
* | Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2015-09-031-2/+6
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking and atomic updates from Ingo Molnar: "Main changes in this cycle are: - Extend atomic primitives with coherent logic op primitives (atomic_{or,and,xor}()) and deprecate the old partial APIs (atomic_{set,clear}_mask()) The old ops were incoherent with incompatible signatures across architectures and with incomplete support. Now every architecture supports the primitives consistently (by Peter Zijlstra) - Generic support for 'relaxed atomics': - _acquire/release/relaxed() flavours of xchg(), cmpxchg() and {add,sub}_return() - atomic_read_acquire() - atomic_set_release() This came out of porting qwrlock code to arm64 (by Will Deacon) - Clean up the fragile static_key APIs that were causing repeat bugs, by introducing a new one: DEFINE_STATIC_KEY_TRUE(name); DEFINE_STATIC_KEY_FALSE(name); which define a key of different types with an initial true/false value. Then allow: static_branch_likely() static_branch_unlikely() to take a key of either type and emit the right instruction for the case. To be able to know the 'type' of the static key we encode it in the jump entry (by Peter Zijlstra) - Static key self-tests (by Jason Baron) - qrwlock optimizations (by Waiman Long) - small futex enhancements (by Davidlohr Bueso) - ... and misc other changes" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits) jump_label/x86: Work around asm build bug on older/backported GCCs locking, ARM, atomics: Define our SMP atomics in terms of _relaxed() operations locking, include/llist: Use linux/atomic.h instead of asm/cmpxchg.h locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics locking/qrwlock: Implement queue_write_unlock() using smp_store_release() locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t' locking, asm-generic: Rework atomic-long.h to avoid bulk code duplication locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic operations locking, compiler.h: Cast away attributes in the WRITE_ONCE() magic locking/static_keys: Make verify_keys() static jump label, locking/static_keys: Update docs locking/static_keys: Provide a selftest jump_label: Provide a self-test s390/uaccess, locking/static_keys: employ static_branch_likely() x86, tsc, locking/static_keys: Employ static_branch_likely() locking/static_keys: Add selftest locking/static_keys: Add a new static_key interface locking/static_keys: Rework update logic locking/static_keys: Add static_key_{en,dis}able() helpers ...
| * | atomic: Collapse all atomic_{set,clear}_mask definitionsPeter Zijlstra2015-07-271-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the now generic definitions of atomic_{set,clear}_mask() into linux/atomic.h to avoid endless and pointless repetition. Also, provide an atomic_andnot() wrapper for those few archs that can implement that. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | atomic: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | arc: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | ARCv2: perf: Finally introduce HS perf unitVineet Gupta2015-08-271-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With all features in place, the ARC HS pct block can now be effectively allowed to be probed/used Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARCv2: perf: implement exclusion of event counting in user or kernel modeAlexey Brodkin2015-08-271-0/+3
| | | | | | | | | | | | | | | | | | | | | Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARCv2: perf: Support sampling events using overflow interruptsAlexey Brodkin2015-08-271-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In times of ARC 700 performance counters didn't have support of interrupt an so for ARC we only had support of non-sampling events. Put simply only "perf stat" was functional. Now with ARC HS we have support of interrupts in performance counters which this change introduces support of. ARC performance counters act in the following way in regard of interrupts generation. [1] A counter counts starting from value set in PCT_COUNT register pair [2] Once counter reaches value set in PCT_INT_CNT interrupt is raised Basic setup look like this: [1] PCT_COUNT = 0; [2] PCT_INT_CNT = __limit_value__; [3] Enable interrupts for that counter and let it run [4] Let counter reach its limit [5] Handle interrupt when it happens Note that PCT HW block is build in CPU core and so ints interrupt line (which is basically OR of all counters IRQs) is wired directly to top-level IRQC. That means do de-assert PCT interrupt it's required to reset IRQs from all counters that have reached their limit values. Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: perf: cap the number of counters to hardware max of 32Vineet Gupta2015-08-271-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The number of counters in PCT can never be more than 32 (while countable conditions could be 100+) for both ARCompact and ARCv2 And while at it update copyright dates. Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: add/fix some comments in code - no functional changeVineet Gupta2015-08-202-12/+12
| | | | | | | | | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: change some branchs to jumps to resolve linkage errorsYuriy Kolerov2015-08-201-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When kernel's binary becomes large enough (32M and more) errors may occur during the final linkage stage. It happens because the build system uses short relocations for ARC by default. This problem may be easily resolved by passing -mlong-calls option to GCC to use long absolute jumps (j) instead of short relative branchs (b). But there are fragments of pure assembler code exist which use branchs in inappropriate places and cause a linkage error because of relocations overflow. First of these fragments is .fixup insertion in futex.h and unaligned.c. It inserts a code in the separate section (.fixup) with branch instruction. It leads to the linkage error when kernel becomes large. Second of these fragments is calling scheduler's functions (common kernel code) from entry.S of ARC's code. When kernel's binary becomes large it may lead to the linkage error because scheduler may occur far enough from ARC's code in the final binary. Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | | ARC: ensure futex ops are atomic in !LLSC configVineet Gupta2015-08-201-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | W/o hardware assisted atomic r-m-w the best we can do is to disable preemption. Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Michel Lespinasse <walken@google.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
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