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2015-10-28ARC: smp: Rename platform hook @init_smp -> @init_cpu_smpVineet Gupta
This conveys better that it is called for each cpu Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_early_smp()Vineet Gupta
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>
2015-10-28ARC: smp: Introduce smp hook @init_early_smp for Master coreVineet Gupta
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>
2015-10-28ARC: remove @init_time, @init_irq platform callbacksVineet Gupta
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>
2015-10-28ARC: smp: irqchip: handle IPI as percpu irq like timerVineet Gupta
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>
2015-10-28ARC: boot: Support Halt-on-reset and Run-on-reset SMP booting modesVineet Gupta
For Run-on-reset, non masters need to spin wait. For Halt-on-reset they can jump to entry point directly. Also while at it, made reset vector handler as "the" entry point for kernel including host debugger based boot (which uses the ELF header entry point) Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-27arc: enable building of all dtbsRob Herring
Enable building all dtb files when CONFIG_OF_ALL_DTBS is enabled. The dtbs are not really dependent on a platform being enabled or any other kernel config, so for testing coverage it is convenient to build all of the dtbs. This builds all dts files in the tree, not just targets listed. Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-27arc: use common make variables for dtb buildsRob Herring
Use dtb-y and always make variables to build dtbs instead of explicit dtbs rule. This is in preparation to support building all dtbs. Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-26arc: axs10x_defconfig: remove CONFIG_MMC_DW_IDMACShawn Lin
DesignWare MMC Controller's transfer mode should be decided at runtime instead of compile-time. So we remove this config option and read dw_mmc's register to select DMA master. Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-10-17ARC: smp: Move default boot kick/wait code out of MCIP into common codeVineet Gupta
For non halt-on-reset case, all cores start of simultaneously in @stext. Master core0 proceeds with kernel boot, while other spin-wait on @wake_flag being set by master once it is ready. So NO hardware assist is needed for master to "kick" the others. This patch moves this soft implementation out of mcip.c (as there is no hardware assist) into common smp.c Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17ARC: boot log: decode more mmu config itemsVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17ARC: boot log: move helper macros to header for reuseVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17ARC: mm: compute TLB size as needed from ways * setsVineet Gupta
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>
2015-10-17ARC: mm: MMU v1..v3 only selectable for ARCompact ISA based coresVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17ARC: make write_aux_reg safer against macro substitutionVineet Gupta
It was generating warnings when called as write_aux_reg(x, paddr >> 32) Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17ARC: [arcompact] entry.S: Elide extra check/branch in exception ret pathVineet Gupta
This is done by improving the laddering logic ! Before: if Exception goto excep_or_pure_k_ret if !Interrupt(L2) goto l1_chk else INTERRUPT_EPILOGUE 2 l1_chk: if !Interrupt(L1) (i.e. pure kernel mode) goto excep_or_pure_k_ret else INTERRUPT_EPILOGUE 1 excep_or_pure_k_ret: EXCEPTION_EPILOGUE Now: if !Interrupt(L1 or L2) (i.e. exception or pure kernel mode) goto excep_or_pure_k_ret ; guaranteed to be an interrupt if !Interrupt(L2) goto l1_ret else INTERRUPT_EPILOGUE 2 ; by virtue of above, no need to chk for L1 active l1_ret: INTERRUPT_EPILOGUE 1 excep_or_pure_k_ret: EXCEPTION_EPILOGUE Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17ARC: [arcompact] entry.S: Document preemption games for L2 intrVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17ARC: [arcompact] entry.S: Improve early return from exceptionVineet Gupta
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>
2015-10-17ARC: [arcompact] don't check for hard isr calling local_irq_enable()Vineet Gupta
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>
2015-10-17ARCv2: mm: THP: flush_pmd_tlb_range make SMP safeVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17ARCv2: mm: THP: Implement flush_pmd_tlb_range() optimizationVineet Gupta
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>
2015-10-17ARCv2: mm: THP: boot validation/reportingVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17ARCv2: mm: THP supportVineet Gupta
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>
2015-10-09ARC: mm: Introduce PTE_SPECIALVineet Gupta
Needed for THP, but will also come in handy for fast GUP later Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-09ARC: mm: pte flags comsetic cleanups, commentsVineet Gupta
No semantical changes Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-09ARC: mm: switch pgtable_to to pte_t *Vineet Gupta
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>
2015-10-06Merge tag 'v4.3-rc4' into locking/core, to pick up fixes before applying new ↵Ingo Molnar
changes Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-04Merge branch 'strscpy' of ↵Linus Torvalds
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
2015-09-23atomic, arch: Audit atomic_{read,set}()Peter Zijlstra
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>
2015-09-16genirq: Remove irq argument from irq flow handlersThomas Gleixner
Most interrupt flow handlers do not use the irq argument. Those few which use it can retrieve the irq number from the irq descriptor. Remove the argument. Search and replace was done with coccinelle and some extra helper scripts around it. Thanks to Julia for her help! Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Jiang Liu <jiang.liu@linux.intel.com>
2015-09-11ARCv2: [axs103_smp] Reduce clk for SMP FPGA configsVineet Gupta
Newer bitfiles needs the reduced clk even for SMP builds Cc: <stable@vger.kernel.org> #4.2 Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-03Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
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 ...
2015-09-01Merge branch 'irq-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "This updated pull request does not contain the last few GIC related patches which were reported to cause a regression. There is a fix available, but I let it breed for a couple of days first. The irq departement provides: - new infrastructure to support non PCI based MSI interrupts - a couple of new irq chip drivers - the usual pile of fixlets and updates to irq chip drivers - preparatory changes for removal of the irq argument from interrupt flow handlers - preparatory changes to remove IRQF_VALID" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits) irqchip/imx-gpcv2: IMX GPCv2 driver for wakeup sources irqchip: Add bcm2836 interrupt controller for Raspberry Pi 2 irqchip: Add documentation for the bcm2836 interrupt controller irqchip/bcm2835: Add support for being used as a second level controller irqchip/bcm2835: Refactor handle_IRQ() calls out of MAKE_HWIRQ PCI: xilinx: Fix typo in function name irqchip/gic: Ensure gic_cpu_if_up/down() programs correct GIC instance irqchip/gic: Only allow the primary GIC to set the CPU map PCI/MSI: pci-xgene-msi: Consolidate chained IRQ handler install/remove unicore32/irq: Prepare puv3_gpio_handler for irq argument removal tile/pci_gx: Prepare trio_handle_level_irq for irq argument removal m68k/irq: Prepare irq handlers for irq argument removal C6X/megamode-pic: Prepare megamod_irq_cascade for irq argument removal blackfin: Prepare irq handlers for irq argument removal arc/irq: Prepare idu_cascade_isr for irq argument removal sparc/irq: Use access helper irq_data_get_affinity_mask() sparc/irq: Use helper irq_data_get_irq_handler_data() parisc/irq: Use access helper irq_data_get_affinity_mask() mn10300/irq: Use access helper irq_data_get_affinity_mask() irqchip/i8259: Prepare i8259_irq_dispatch for irq argument removal ...
2015-08-27ARCv2: entry: Fix reserved handlerVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27ARCv2: perf: Finally introduce HS perf unitVineet Gupta
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>
2015-08-27ARCv2: perf: SMP supportAlexey Brodkin
* split off pmu info into singleton and per-cpu bits * setup PMU on all cores 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>
2015-08-27ARCv2: perf: implement exclusion of event counting in user or kernel modeAlexey Brodkin
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>
2015-08-27ARCv2: perf: Support sampling events using overflow interruptsAlexey Brodkin
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>
2015-08-27ARCv2: perf: implement "event_set_period"Alexey Brodkin
This generalization prepares for support of overflow interrupts. Hardware event counters on ARC work that way: Each counter counts from programmed start value (set in ARC_REG_PCT_COUNT) to a limit value (set in ARC_REG_PCT_INT_CNT) and once limit value is reached this timer generates an interrupt. Even though this hardware implementation allows for more flexibility, in Linux kernel we decided to mimic behavior of other architectures this way: [1] Set limit value as half of counter's max value (to allow counter to run after reaching it limit, see below for more explanation): ---------->8----------- arc_pmu->max_period = (1ULL << counter_size) / 2 - 1ULL; ---------->8----------- [2] Set start value as "arc_pmu->max_period - sample_period" and then count up to the limit Our event counters don't stop on reaching max value (the one we set in ARC_REG_PCT_INT_CNT) but continue to count until kernel explicitly stops each of them. And setting a limit as half of counter capacity is done to allow capturing of additional events in between moment when interrupt was triggered until we're actually processing PMU interrupts. That way we're trying to be more precise. For example if we count CPU cycles we keep track of cycles while running through generic IRQ handling code: [1] We set counter period as say 100_000 events of type "crun" [2] Counter reaches that limit and raises its interrupt [3] Once we get in PMU IRQ handler we read current counter value from ARC_REG_PCT_SNAP ans see there something like 105_000. If counters stop on reaching a limit value then we would miss additional 5000 cycles. 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>
2015-08-27ARC: perf: cap the number of counters to hardware max of 32Vineet Gupta
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>
2015-08-21ARC: Eliminate some ARCv2 specific code for ARCompact buildVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20ARC: add/fix some comments in code - no functional changeVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20ARC: change some branchs to jumps to resolve linkage errorsYuriy Kolerov
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>
2015-08-20ARC: ensure futex ops are atomic in !LLSC configVineet Gupta
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>
2015-08-20ARC: Enable HAVE_FUTEX_CMPXCHGVineet Gupta
ARC doesn't need the runtime detection of futex cmpxchg op Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20ARC: make futex_atomic_cmpxchg_inatomic() return bimodalVineet Gupta
Callers of cmpxchg_futex_value_locked() in futex code expect bimodal return value: !0 (essentially -EFAULT as failure) 0 (success) Before this patch, the success return value was old value of futex, which could very well be non zero, causing caller to possibly take the failure path erroneously. Fix that by returning 0 for success (This fix was done back in 2011 for all upstream arches, which ARC obviously missed) 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>
2015-08-20ARC: futex cosmeticsVineet Gupta
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>
2015-08-20ARC: add barriers to futex codeVineet Gupta
The atomic ops on futex need to provide the full barrier just like regular atomics in kernel. Also remove pagefault_enable/disable in futex_atomic_cmpxchg_inatomic() as core code already does that 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>
2015-08-20ARCv2: IOC: Allow boot time disableAlexey Brodkin
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20ARCv2: SLC: Allow boot time disableVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>