linux/arch/arc/kernel, branch v4.9

ARCv2: MCIP: Use IDU_M_DISTRI_DEST mode if there is only 1 destination core

2016-11-08T20:22:52Z

ARC linux uses 2 distribution modes for common interrupts: round robin mode (IDU_M_DISTRI_RR) and a simple destination mode (IDU_M_DISTRI_DEST). The first one is used when more than 1 cores may handle a common interrupt and the second one is used when only 1 core may handle a common interrupt. However idu_irq_set_affinity() always sets IDU_M_DISTRI_RR for all affinity values. But there is no sense in setting of such mode if only 1 core must handle a common interrupt. Signed-off-by: Yuriy Kolerov Signed-off-by: Vineet Gupta

ARC: IRQ: Do not use hwirq as virq and vice versa

2016-11-08T20:05:10Z

This came up when reviewing code to address missing IRQ affinity setting in AXS103 platform and/or implementing hierarchical IRQ domains - smp_ipi_irq_setup() callers pass hwirq but in turn calls request_percpu_irq() which expects a linux virq. So invoke irq_find_mapping() to do the conversion (also explicitify this in code by renaming the args appropriately) - idu_of_init()/idu_cascade_isr() were similarly using linux virq where hwirq is expected, so do the conversion using irqd_to_hwirq() helper Signed-off-by: Yuriy Kolerov [vgupta: made changelog a bit concise a bit] Signed-off-by: Vineet Gupta

ARC: [plat-eznps] set default baud for early console

2016-11-08T17:39:37Z

For CONFIG_SERIAL_EARLYCON we need 800MHz for NPS SoC The early console driver uses BASE_BAUD and not using dtb. The default of 50MHz is NOT good for NPS SoC. Signed-off-by: Noam Camus Signed-off-by: Vineet Gupta

ARC: timer: rtc: implement read loop in "C" vs. inline asm

2016-11-07T19:19:44Z

The current code doesn't even compile as somehow the inline assembly can't see the register names defined as ARC_RTC_* I'm pretty sure It worked when I first got it merged, but the tools were definitely different then. So better to write this in "C" anyways. CC: stable@vger.kernel.org #4.2+ Acked-by: Daniel Lezcano Signed-off-by: Vineet Gupta

ARC: change return value of userspace cmpxchg assist syscall

2016-11-07T19:01:12Z

The original syscall only used to return errno to indicate if cmpxchg succeeded. It was not returning the "previous" value which typical cmpxchg callers are interested in to build their slowpaths or retry loops. Given user preemption in syscall return path etc, it is not wise to check this in userspace afterwards, but should be what kernel actually observed in the syscall. So change the syscall interface to always return the previous value and additionally set Z flag to indicate whether operation succeeded or not (just like ARM implementation when they used to have this syscall) The flag approach avoids having to put_user errno which is nice given the use case for this syscall cares mostly about the "previous" value. Signed-off-by: Vineet Gupta

ARC: [SMP] avoid overriding present cpumask

2016-11-01T00:12:41Z

At smp_prepare_cpus() we set present cpu mask as part of init for all CPUs at range [0-max_cpus]. This is done without checking if this mask is already being set. At platform of eznps this mask is already being initialized at smp_init_cpus() by using hook plat_smp_ops.init_early_smp(). So to avoid overriding of present cpu mask we check the number of bits which are set in this mask. At the begin only bit for boot CPU is set so if number of bits already set is no more than one we can be assure that there is no overriding of this mask. Signed-off-by: Noam Camus Signed-off-by: Vineet Gupta

ARC: module: print pretty section names

2016-10-28T17:10:29Z

Now that we have referece to section name string table in apply_relocate_add(), use it to - print the name of section being relocated - print symbol with NULL name (since it refers to a section) before | Section to fixup 7000a060 | ========================================================= | rela->r_off | rela->addend | sym->st_value | ADDR | VALUE | ========================================================= | 1c 0 7000e000 7000a07c 7000e000 [] | 40 0 7000a000 7000a0a0 7000a000 [] after | Section to fixup .eh_frame @7000a060 | ========================================================= | r_off r_add st_value ADDRESS VALUE | ========================================================= | 1c 0 7000e000 7000a07c 7000e000 [.init.text] | 40 0 7000a000 7000a0a0 7000a000 [.exit.text] Signed-off-by: Vineet Gupta

ARC: module: elide loop to save reference to .eh_frame

2016-10-28T17:10:28Z

The loop was really needed in .debug_frame regime where wanted make it as SH_ALLOC so that apply_relocate_add() would process it. That's not needed for .eh_frame, so we check this in apply_relocate_add() which gets called for each section. Note that we need to save reference to "section name strings" section in module_frob_arch_sections() since apply_relocate_add() doesn't get that Signed-off-by: Vineet Gupta

ARC: mm: retire ARC_DBG_TLB_MISS_COUNT...

2016-10-28T17:10:28Z

... given that we have perf counters abel to do the same thing non intrusively Signed-off-by: Vineet Gupta

ARC: boot log: refactor cpu name/release printing

2016-10-28T17:09:07Z

The motivation is to identify ARC750 vs. ARC770 (we currently print generic "ARC700"). A given ARC700 release could be 750 or 770, with same ARCNUM (or family identifier which is unfortunate). The existing arc_cpu_tbl[] kept a single concatenated string for core name and release which thus doesn't work for 750 vs. 770 identification. So split this into 2 tables, one with core names and other with release. And while we are at it, get rid of the range checking for family numbers. We just document the known to exist cores running Linux and ditch others. With this in place, we add detection of ARC750 which is - cores 0x33 and before - cores 0x34 and later with MMUv2 Signed-off-by: Vineet Gupta