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2016-03-12ARC: [BE] readl()/writel() to work in Big Endian CPU configurationLada Trimasova
read{l,w}() write{l,w}() primitives should use le{16,32}_to_cpu() and cpu_to_le{16,32}() respectively to ensure device registers are read correctly in Big Endian CPU configuration. Per Arnd Bergmann | Most drivers using readl() or readl_relaxed() expect those to perform byte | swaps on big-endian architectures, as the registers tend to be fixed endian This was needed for getting UART to work correctly on a Big Endian ARC. The ARC accessors originally were fine, and the bug got introduced inadventently by commit b8a033023994 ("ARCv2: barriers") Fixes: b8a033023994 ("ARCv2: barriers") Link: http://lkml.kernel.org/r/201603100845.30602.arnd@arndb.de Cc: Alexey Brodkin <abrodkin@synopsys.com> Cc: stable@vger.kernel.org [4.2+] Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Lada Trimasova <ltrimas@synopsys.com> [vgupta: beefed up changelog, added Fixes/stable tags] Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-03-11ARC: bitops: Remove non relevant commentsVineet Gupta
commit 80f420842ff42 removed the ARC bitops microoptimization but failed to prune the comments to same effect Fixes: 80f420842ff42 ("ARC: Make ARC bitops "safer" (add anti-optimization)") Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-03-11ARC: Fix misspellings in comments.Adam Buchbinder
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-02-24ARCv2: SMP: Push IPI_IRQ into IPI providerVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-02-24ARC: [intc-compact] Remove IPI setup from ARCompact portVineet Gupta
There is no real ARC700 based SMP SoC so remove IPI definition. EZChip's SMP ARC700 is going to use a different intc and IPI provider anyways. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-02-24ARCv2: SMP: Emulate IPI to self using software triggered interruptVineet Gupta
ARConnect/MCIP Inter-Core-Interrupt module can't send interrupt to local core. So use core intc capability to trigger software interrupt to self, using an unsued IRQ #21. This showed up as csd deadlock with LTP trace_sched on a dual core system. This test acts as scheduler fuzzer, triggering all sorts of schedulting activity. Trouble starts with IPI to self, which doesn't get delivered (effectively lost due to H/w capability), but the msg intended to be sent remain enqueued in per-cpu @ipi_data. All subsequent IPIs to this core from other cores get elided due to the IPI coalescing optimization in ipi_send_msg_one() where a pending msg implies an IPI already sent and assumes other core is yet to ack it. After the elided IPI, other core simply goes into csd_lock_wait() but never comes out as this core never sees the interrupt. Fixes STAR 9001008624 Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> [4.2] Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-02-18ARCv2: boot report CCMs (Closely Coupled Memories)Vineet Gupta
- ARCv2 uses a seperate BCR for {I,D}CCM base address: ARCompact encoded both base/size in same BCR - Size encoding in common BCR is different for ARCompact/ARCv2 Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-02-13Merge tag 'arc-4.5-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc Pull ARC fixes from Vineet Gupta: "I've been sitting on some of these fixes for a while. - Corner case of returning to delay slot from interrupt - Changing default interrupt prioiry level - Kconfig'ize support for super pages - Other minor fixes" * tag 'arc-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: mm: Introduce explicit super page size support ARCv2: intc: Allow interruption by lowest priority interrupt ARCv2: Check for LL-SC livelock only if LLSC is enabled ARC: shrink cpuinfo by not saving full timer BCR ARCv2: clocksource: Rename GRTC -> GFRC ... ARCv2: STAR 9000950267: Handle return from intr to Delay Slot #2
2016-02-12ARC: mm: Introduce explicit super page size supportVineet Gupta
MMUv4 supports 2 concurrent page sizes: Normal and Super [4K to 16M] So far Linux supported a single super page size for a given Normal page, depending on the software page walking address split. e.g. we had 11:8:13 address split for 8K page, which meant super page was 2 ^(8+13) = 2M (given that THP size has to be PMD_SHIFT) Now we turn this around, by allowing multiple Super Pages in Kconfig (currently 2M and 16M only) and forcing page walker address split to PGDIR_SHIFT and PAGE_SHIFT For configs without Super page, things are same as before and PGDIR_SHIFT can be hacked to get non default address split The motivation for this change is a customer who needs 16M super page and a 8K Normal page combo. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-02-10ARCv2: intc: Allow interruption by lowest priority interruptVineet Gupta
ARC HS Cores support configurable multiple interrupt priorities of upto 16 levels. There is processor "interrupt preemption threshhold" in STATUS32.E[4:1] And several places need to set this up: 1. seed value as kernel is booting 2. seed value for user space programs 3. Arg to SLEEP instruction in idle task (what interrupt prio can wake) 4. Per-IRQ line prioirty (i.e. what is the priority of interrupt raised by a peripheral or timer or perf counter... Currently above sites use the highest priority 0. This can be potential problem when multiple priorities are supported. e.g. user space could only be interrupted by P0 interrupt, not others... So turn this over and instead make default interruption level to be the lowest priority possible 15. This should be fine even if there are fewer priority levels configured (say two: P0 HIGH, P1 LOW) This feature also effectively disables FIRQ feature if present in hardware config. With old code, a P0 interrupt would be FIRQ, needing special handling (ISR or Register Banks) which is NOT supported yet. Now it not be P0 (P15 or whatever is lowest prio) so FIRQ is not triggered. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-01-29ARC: shrink cpuinfo by not saving full timer BCRVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-01-29ARCv2: clocksource: Rename GRTC -> GFRC ...Vineet Gupta
... it is now called Global Free Running Counter Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-01-20dma-mapping: always provide the dma_map_ops based implementationChristoph Hellwig
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>
2016-01-20arc: convert to dma_map_opsChristoph Hellwig
[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>
2015-12-21ARC: mm: fix building for MMU v2Alexey Brodkin
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>
2015-12-17ARC: smp: Rename platform hook @init_cpu_smp -> @init_per_cpuVineet Gupta
Makes it similar to smp_ops which also has callback with same name Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17ARC: rename smp operation init_irq_cpu() to init_per_cpu()Noam Camus
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>
2015-12-17ARC: dw2 unwind: Reinstante unwinding out of modulesVineet Gupta
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>
2015-11-16ARCv2: Use the default irq priority for idle sleepVineet Gupta
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>
2015-11-16ARC: Abstract out ISA specific SLEEP argsVineet Gupta
No semantical changes, prepares for ARCv2 specific change in next commit Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-14Merge tag 'arc-4.4-rc1-part2' of ↵Linus Torvalds
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
2015-11-14ARC: cpu_relax() to be compiler barrier even for UPVineet Gupta
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>
2015-11-03Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
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
2015-10-29ARC: mm: PAE40 supportVineet Gupta
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>
2015-10-28ARC: mm: PAE40: switch to using phys_addr_t for physical addressesVineet Gupta
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>
2015-10-28ARC: mm: HIGHMEM: kmap API implementationVineet Gupta
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>
2015-10-28ARC: mm: preps ahead of HIGHMEM supportVineet Gupta
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>
2015-10-28ARC: mm: use generic macros _BITUL()/_AC()Alexey Brodkin
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_smp()Vineet Gupta
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>
2015-10-28ARC: smp: Introduce smp hook @init_irq_cpu called for all coresVineet Gupta
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>
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>
2015-10-17ARC: 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: 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: 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 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>