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* arch: mm: pass userspace fault flag to generic fault handlerJohannes Weiner2013-09-121-2/+4
| | | | | | | | | | | | | | | | | | | | Unlike global OOM handling, memory cgroup code will invoke the OOM killer in any OOM situation because it has no way of telling faults occuring in kernel context - which could be handled more gracefully - from user-triggered faults. Pass a flag that identifies faults originating in user space from the architecture-specific fault handlers to generic code so that memcg OOM handling can be improved. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arch: mm: remove obsolete init OOM protectionJohannes Weiner2013-09-121-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The memcg code can trap tasks in the context of the failing allocation until an OOM situation is resolved. They can hold all kinds of locks (fs, mm) at this point, which makes it prone to deadlocking. This series converts memcg OOM handling into a two step process that is started in the charge context, but any waiting is done after the fault stack is fully unwound. Patches 1-4 prepare architecture handlers to support the new memcg requirements, but in doing so they also remove old cruft and unify out-of-memory behavior across architectures. Patch 5 disables the memcg OOM handling for syscalls, readahead, kernel faults, because they can gracefully unwind the stack with -ENOMEM. OOM handling is restricted to user triggered faults that have no other option. Patch 6 reworks memcg's hierarchical OOM locking to make it a little more obvious wth is going on in there: reduce locked regions, rename locking functions, reorder and document. Patch 7 implements the two-part OOM handling such that tasks are never trapped with the full charge stack in an OOM situation. This patch: Back before smart OOM killing, when faulting tasks were killed directly on allocation failures, the arch-specific fault handlers needed special protection for the init process. Now that all fault handlers call into the generic OOM killer (see commit 609838cfed97: "mm: invoke oom-killer from remaining unconverted page fault handlers"), which already provides init protection, the arch-specific leftovers can be removed. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Acked-by: Vineet Gupta <vgupta@synopsys.com> [arch/arc bits] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linuxLinus Torvalds2013-09-101-3/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull device tree core updates from Grant Likely: "Generally minor changes. A bunch of bug fixes, particularly for initialization and some refactoring. Most notable change if feeding the entire flattened tree into the random pool at boot. May not be significant, but shouldn't hurt either" Tim Bird questions whether the boot time cost of the random feeding may be noticeable. And "add_device_randomness()" is definitely not some speed deamon of a function. * tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux: of/platform: add error reporting to of_amba_device_create() irq/of: Fix comment typo for irq_of_parse_and_map of: Feed entire flattened device tree into the random pool of/fdt: Clean up casting in unflattening path of/fdt: Remove duplicate memory clearing on FDT unflattening gpio: implement gpio-ranges binding document fix of: call __of_parse_phandle_with_args from of_parse_phandle of: introduce of_parse_phandle_with_fixed_args of: move of_parse_phandle() of: move documentation of of_parse_phandle_with_args of: Fix missing memory initialization on FDT unflattening of: consolidate definition of early_init_dt_alloc_memory_arch() of: Make of_get_phy_mode() return int i.s.o. const int include: dt-binding: input: create a DT header defining key codes. of/platform: Staticize of_platform_device_create_pdata() of: Specify initrd location using 64-bit dt: Typo fix OF: make of_property_for_each_{u32|string}() use parameters if OF is not enabled
| * of: Specify initrd location using 64-bitSantosh Shilimkar2013-07-241-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On some PAE architectures, the entire range of physical memory could reside outside the 32-bit limit. These systems need the ability to specify the initrd location using 64-bit numbers. This patch globally modifies the early_init_dt_setup_initrd_arch() function to use 64-bit numbers instead of the current unsigned long. There has been quite a bit of debate about whether to use u64 or phys_addr_t. It was concluded to stick to u64 to be consistent with rest of the device tree code. As summarized by Geert, "The address to load the initrd is decided by the bootloader/user and set at that point later in time. The dtb should not be tied to the kernel you are booting" More details on the discussion can be found here: https://lkml.org/lkml/2013/6/20/690 https://lkml.org/lkml/2012/9/13/544 Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Rob Herring <rob.herring@calxeda.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Signed-off-by: Grant Likely <grant.likely@linaro.org>
* | ARC: [ASID] Track ASID allocation cycles/generationsVineet Gupta2013-08-302-16/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This helps remove asid-to-mm reverse map While mm->context.id contains the ASID assigned to a process, our ASID allocator also used asid_mm_map[] reverse map. In a new allocation cycle (mm->ASID >= @asid_cache), the Round Robin ASID allocator used this to check if new @asid_cache belonged to some mm2 (from prev cycle). If so, it could locate that mm using the ASID reverse map, and mark that mm as unallocated ASID, to force it to refresh at the time of switch_mm() However, for SMP, the reverse map has to be maintained per CPU, so becomes 2 dimensional, hence got rid of it. With reverse map gone, it is NOT possible to reach out to current assignee. So we track the ASID allocation generation/cycle and on every switch_mm(), check if the current generation of CPU ASID is same as mm's ASID; If not it is refreshed. (Based loosely on arch/sh implementation) Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: [ASID] get_new_mmu_context() to conditionally allocate new ASIDVineet Gupta2013-08-301-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ASID allocation changes/1 This patch does 2 things: (1) get_new_mmu_context() NOW moves mm->ASID to a new value ONLY if it was from a prev allocation cycle/generation OR if mm had no ASID allocated (vs. before would unconditionally moving to a new ASID) Callers desiring unconditional update of ASID, e.g.local_flush_tlb_mm() (for parent's address space invalidation at fork) need to first force the parent to an unallocated ASID. (2) get_new_mmu_context() always sets the MMU PID reg with unchanged/new ASID value. The gains are: - consolidation of all asid alloc logic into get_new_mmu_context() - avoiding code duplication in switch_mm() for PID reg setting - Enables future change to fold activate_mm() into switch_mm() Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: [ASID] Refactor the TLB paranoid debug codeVineet Gupta2013-08-302-20/+20
| | | | | | | | | | | | | | -Asm code already has values of SW and HW ASID values, so they can be passed to the printing routine. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: No need to flush the TLB in early bootVineet Gupta2013-08-301-7/+0
| | | | | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: MMUv4 preps/3 - Abstract out TLB Insert/DeleteVineet Gupta2013-08-301-40/+54
| | | | | | | | | | | | | | This reorganizes the current TLB operations into psuedo-ops to better pair with MMUv4's native Insert/Delete operations Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: MMUv4 preps/2 - Reshuffle PTE bitsVineet Gupta2013-08-302-11/+3
| | | | | | | | | | | | | | | | | | | | With previous commit freeing up PTE bits, reassign them so as to: - Match the bit to H/w counterpart where possible (e.g. MMUv2 GLOBAL/PRESENT, this avoids a shift in create_tlb()) - Avoid holes in _PAGE_xxx definitions Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: MMUv4 preps/1 - Fold PTE K/U access flagsVineet Gupta2013-08-292-23/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current ARC VM code has 13 flags in Page Table entry: some software (accesed/dirty/non-linear-maps) and rest hardware specific. With 8k MMU page, we need 19 bits for addressing page frame so remaining 13 bits is just about enough to accomodate the current flags. In MMUv4 there are 2 additional flags, SZ (normal or super page) and WT (cache access mode write-thru) - and additionally PFN is 20 bits (vs. 19 before for 8k). Thus these can't be held in current PTE w/o making each entry 64bit wide. It seems there is some scope of compressing the current PTE flags (and freeing up a few bits). Currently PTE contains fully orthogonal distinct access permissions for kernel and user mode (Kr, Kw, Kx; Ur, Uw, Ux) which can be folded into one set (R, W, X). The translation of 3 PTE bits into 6 TLB bits (when programming the MMU) can be done based on following pre-requites/assumptions: 1. For kernel-mode-only translations (vmalloc: 0x7000_0000 to 0x7FFF_FFFF), PTE additionally has PAGE_GLOBAL flag set (and user space entries can never be global). Thus such a PTE can translate to Kr, Kw, Kx (as appropriate) and zero for User mode counterparts. 2. For non global entries, the PTE flags can be used to create mirrored K and U TLB bits. This is true after commit a950549c675f2c8c504 "ARC: copy_(to|from)_user() to honor usermode-access permissions" which ensured that user-space translations _MUST_ have same access permissions for both U/K mode accesses so that copy_{to,from}_user() play fair with fault based CoW break and such... There is no such thing as free lunch - the cost is slightly infalted TLB-Miss Handlers. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: Code cosmetics (Nothing semantical)Vineet Gupta2013-08-292-72/+67
| | | | | | | | | | | | | | | | * reduce editor lines taken by pt_regs * ARCompact ISA specific part of TLB Miss handlers clubbed together * cleanup some comments Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: Exception Handlers Code consolidationVineet Gupta2013-08-261-7/+1
|/ | | | | | | | | | | | | | | After the recent cleanups, all the exception handlers now have same boilerplate prologue code. Move that into common macro. This reduces readability but helps greatly with sharing / duplicating entry code with ARCv2 ISA where the handlers are pretty much the same, just the entry prologue is different (due to hardware assist). Also while at it, add the missing FAKE_RET_FROM_EXCPN calls in couple of places to drop down to pure kernel mode (from exception mode) before jumping off into "C" code. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* mm: invoke oom-killer from remaining unconverted page fault handlersJohannes Weiner2013-07-091-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | A few remaining architectures directly kill the page faulting task in an out of memory situation. This is usually not a good idea since that task might not even use a significant amount of memory and so may not be the optimal victim to resolve the situation. Since 2.6.29's 1c0fe6e ("mm: invoke oom-killer from page fault") there is a hook that architecture page fault handlers are supposed to call to invoke the OOM killer and let it pick the right task to kill. Convert the remaining architectures over to this hook. To have the previous behavior of simply taking out the faulting task the vm.oom_kill_allocating_task sysctl can be set to 1. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> [arch/arc bits] Cc: James Hogan <james.hogan@imgtec.com> Cc: David Howells <dhowells@redhat.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (updates from Andrew Morton)Linus Torvalds2013-07-031-36/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge first patch-bomb from Andrew Morton: - various misc bits - I'm been patchmonkeying ocfs2 for a while, as Joel and Mark have been distracted. There has been quite a bit of activity. - About half the MM queue - Some backlight bits - Various lib/ updates - checkpatch updates - zillions more little rtc patches - ptrace - signals - exec - procfs - rapidio - nbd - aoe - pps - memstick - tools/testing/selftests updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (445 commits) tools/testing/selftests: don't assume the x bit is set on scripts selftests: add .gitignore for kcmp selftests: fix clean target in kcmp Makefile selftests: add .gitignore for vm selftests: add hugetlbfstest self-test: fix make clean selftests: exit 1 on failure kernel/resource.c: remove the unneeded assignment in function __find_resource aio: fix wrong comment in aio_complete() drivers/w1/slaves/w1_ds2408.c: add magic sequence to disable P0 test mode drivers/memstick/host/r592.c: convert to module_pci_driver drivers/memstick/host/jmb38x_ms: convert to module_pci_driver pps-gpio: add device-tree binding and support drivers/pps/clients/pps-gpio.c: convert to module_platform_driver drivers/pps/clients/pps-gpio.c: convert to devm_* helpers drivers/parport/share.c: use kzalloc Documentation/accounting/getdelays.c: avoid strncpy in accounting tool aoe: update internal version number to v83 aoe: update copyright date aoe: perform I/O completions in parallel ...
| * mm/ARC: prepare for removing num_physpages and simplify mem_init()Jiang Liu2013-07-031-33/+3
| | | | | | | | | | | | | | | | | | | | | | Prepare for removing num_physpages and simplify mem_init(). Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> # for arch/arc Cc: James Hogan <james.hogan@imgtec.com> Cc: Rob Herring <rob.herring@calxeda.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: concentrate modification of totalram_pages into the mm coreJiang Liu2013-07-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Concentrate code to modify totalram_pages into the mm core, so the arch memory initialized code doesn't need to take care of it. With these changes applied, only following functions from mm core modify global variable totalram_pages: free_bootmem_late(), free_all_bootmem(), free_all_bootmem_node(), adjust_managed_page_count(). With this patch applied, it will be much more easier for us to keep totalram_pages and zone->managed_pages in consistence. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Acked-by: David Howells <dhowells@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: <sworddragon2@aol.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: enhance free_reserved_area() to support poisoning memory with zeroJiang Liu2013-07-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Address more review comments from last round of code review. 1) Enhance free_reserved_area() to support poisoning freed memory with pattern '0'. This could be used to get rid of poison_init_mem() on ARM64. 2) A previous patch has disabled memory poison for initmem on s390 by mistake, so restore to the original behavior. 3) Remove redundant PAGE_ALIGN() when calling free_reserved_area(). Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: <sworddragon2@aol.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: change signature of free_reserved_area() to fix building warningsJiang Liu2013-07-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change signature of free_reserved_area() according to Russell King's suggestion to fix following build warnings: arch/arm/mm/init.c: In function 'mem_init': arch/arm/mm/init.c:603:2: warning: passing argument 1 of 'free_reserved_area' makes integer from pointer without a cast [enabled by default] free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL); ^ In file included from include/linux/mman.h:4:0, from arch/arm/mm/init.c:15: include/linux/mm.h:1301:22: note: expected 'long unsigned int' but argument is of type 'void *' extern unsigned long free_reserved_area(unsigned long start, unsigned long end, mm/page_alloc.c: In function 'free_reserved_area': >> mm/page_alloc.c:5134:3: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default] In file included from arch/mips/include/asm/page.h:49:0, from include/linux/mmzone.h:20, from include/linux/gfp.h:4, from include/linux/mm.h:8, from mm/page_alloc.c:18: arch/mips/include/asm/io.h:119:29: note: expected 'const volatile void *' but argument is of type 'long unsigned int' mm/page_alloc.c: In function 'free_area_init_nodes': mm/page_alloc.c:5030:34: warning: array subscript is below array bounds [-Warray-bounds] Also address some minor code review comments. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Reported-by: Arnd Bergmann <arnd@arndb.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: <sworddragon2@aol.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | arc: delete __cpuinit usage from all arc filesPaul Gortmaker2013-06-272-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) are flagged as __cpuinit -- so if we remove the __cpuinit from arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the arch/arc uses of the __cpuinit macros from all C files. Currently arc does not have any __CPUINIT used in assembly files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: [tlb-miss] Fix bug with CONFIG_ARC_DBG_TLB_MISS_COUNTVineet Gupta2013-06-271-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | LOAD_FAULT_PTE macro is expected to set r2 with faulting vaddr. However in case of CONFIG_ARC_DBG_TLB_MISS_COUNT, it was getting clobbered with statistics collection code. Fix latter by using a different register. Note that only I-TLB Miss handler was potentially affected. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: [tlb-miss] Extraneous PTE bit testing/settingVineet Gupta2013-06-271-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | * No need to check for READ access in I-TLB Miss handler * Redundant PAGE_PRESENT update in PTE Post TLB entry installation, in updating PTE for software accessed/dity bits, no need to update PAGE_PRESENT since it will already be set. Infact the entry won't have installed if !PAGE_PRESENT. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: Remove explicit passing around of ECRVineet Gupta2013-06-262-8/+5
| | | | | | | | | | | | | | | | | | | | | | | | With ECR now part of pt_regs * No need to propagate from lowest asm handlers as arg * No need to save it in tsk->thread.cause_code * Avoid bit chopping to access the bit-fields More code consolidation, cleanup Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: [mm] Remove @write argument to do_page_fault()Vineet Gupta2013-06-222-13/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This can be ascertained within do_page_fault() since it gets the full ECR (Exception Cause Register). Further, for both the callers of do_page_fault(): Prot-V / D-TLB-Miss, the cause sub-fields in ECR are same for same type of access, making the code much more simpler. D-TLB-Miss [LD] 0x00_21_01_00 Prot-V [LD] 0x00_23_01_00 ^^ D-TLB-Miss [ST] 0x00_21_02_00 Prot-V [ST] 0x00_23_02_00 ^^ D-TLB-Miss [EX] 0x00_21_03_00 Prot-V [EX] 0x00_23_03_00 ^^ This helps code consolidation, which is even better when moving code from assembler to "C". Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: [mm] Assume pagecache page dirty by defaultVineet Gupta2013-06-222-7/+7
| | | | | | | | | | | | Similar to ARM/SH Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: [mm] optimise VIPT dcache aliasing 2/xVineet Gupta2013-06-221-0/+1
| | | | | | | | | | | | | | Non-congruent SRC page in copy_user_page() is dcache clean in the end - so record that fact, to avoid a subsequent extraneous flush. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: [mm] optimise VIPT dcache aliasing 1/xVineet Gupta2013-06-221-1/+6
| | | | | | | | | | | | flush_cache_page() - kills icache only if page is executable Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: [mm] Zero page optimizationVineet Gupta2013-06-221-1/+5
| | | | | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: No-op full icache flush if !CONFIG_ARC_HAS_ICACHEVineet Gupta2013-06-221-19/+9
| | | | | | | | | | | | Also remove extraneous irq disabling in flush_cache_all() callstack Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: cache detection code bitrotVineet Gupta2013-06-221-21/+10
| | | | | | | | | | | | | | | | | | * Number of (i|d)cache ways can be retrieved from BCRs and hence no need to cross check with with built-in constants * Use of IS_ENABLED() to check for a Kconfig option * is_not_cache_aligned() not used anymore Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: Disintegrate arcregs.hVineet Gupta2013-06-224-9/+57
| | | | | | | | | | | | | | | | | | * Move the various sub-system defines/types into relevant files/functions (reduces compilation time) * move CPU specific stuff out of asm/tlb.h into asm/mmu.h Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | ARC: Use kconfig helper IS_ENABLED() to get rid of defines.hVineet Gupta2013-06-222-3/+5
|/ | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: lazy dcache flush broke gdb in non-aliasing configsVineet Gupta2013-05-251-10/+11
| | | | | | | | | | | | | gdbserver inserting a breakpoint ends up calling copy_user_page() for a code page. The generic version of which (non-aliasing config) didn't set the PG_arch_1 bit hence update_mmu_cache() didn't sync dcache/icache for corresponding dynamic loader code page - causing garbade to be executed. So now aliasing versions of copy_user_highpage()/clear_page() are made default. There is no significant overhead since all of special alias handling code is compiled out for non-aliasing build Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Brown paper bag bug in macro for checking cache colorVineet Gupta2013-05-231-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | The VM_EXEC check in update_mmu_cache() was getting optimized away because of a stupid error in definition of macro addr_not_cache_congruent() The intention was to have the equivalent of following: if (a || (1 ? b : 0)) but we ended up with following: if (a || 1 ? b : 0) And because precedence of '||' is more that that of '?', gcc was optimizing away evaluation of <a> Nasty Repercussions: 1. For non-aliasing configs it would mean some extraneous dcache flushes for non-code pages if U/K mappings were not congruent. 2. For aliasing config, some needed dcache flush for code pages might be missed if U/K mappings were congruent. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: copy_(to|from)_user() to honor usermode-access permissionsVineet Gupta2013-05-231-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This manifested as grep failing psuedo-randomly: -------------->8--------------------- [ARCLinux]$ ip address show lo | grep inet [ARCLinux]$ ip address show lo | grep inet [ARCLinux]$ ip address show lo | grep inet [ARCLinux]$ [ARCLinux]$ ip address show lo | grep inet inet 127.0.0.1/8 scope host lo -------------->8--------------------- ARC700 MMU provides fully orthogonal permission bits per page: Ur, Uw, Ux, Kr, Kw, Kx The user mode page permission templates used to have all Kernel mode access bits enabled. This caused a tricky race condition observed with uClibc buffered file read and UNIX pipes. 1. Read access to an anon mapped page in libc .bss: write-protected zero_page mapped: TLB Entry installed with Ur + K[rwx] 2. grep calls libc:getc() -> buffered read layer calls read(2) with the internal read buffer in same .bss page. The read() call is on STDIN which has been redirected to a pipe. read(2) => sys_read() => pipe_read() => copy_to_user() 3. Since page has Kernel-write permission (despite being user-mode write-protected), copy_to_user() suceeds w/o taking a MMU TLB-Miss Exception (page-fault for ARC). core-MM is unaware that kernel erroneously wrote to the reserved read-only zero-page (BUG #1) 4. Control returns to userspace which now does a write to same .bss page Since Linux MM is not aware that page has been modified by kernel, it simply reassigns a new writable zero-init page to mapping, loosing the prior write by kernel - effectively zero'ing out the libc read buffer under the hood - hence grep doesn't see right data (BUG #2) The fix is to make all kernel-mode access permissions mirror the user-mode ones. Note that the kernel still has full access to pages, when accessed directly (w/o MMU) - this fix ensures that kernel-mode access in copy_to_from() path uses the same faulting access model as for pure user accesses to keep MM fully aware of page state. The issue is peudo-random because it only shows up if the TLB entry installed in #1 is present at the time of #3. If it is evicted out, due to TLB pressure or some-such, then copy_to_user() does take a TLB Miss Exception, with a routine write-to-anon COW processing installing a fresh page for kernel writes and also usable as it is in userspace. Further the issue was dormant for so long as it depends on where the libc internal read buffer (in .bss) is mapped at runtime. If it happens to reside in file-backed data mapping of libc (in the page-aligned slack space trailing the file backed data), loader zero padding the slack space, does the early cow page replacement, setting things up at the very beginning itself. With gcc 4.8 based builds, the libc buffer got pushed out to a real anon mapping which triggers the issue. Reported-by: Anton Kolesov <akolesov@synopsys.com> Cc: <stable@vger.kernel.org> # 3.9 Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: [mm] Prevent stray dcache lines after__sync_icache_dcach()Vineet Gupta2013-05-231-1/+1
| | | | | | | | | | | Flush and INVALIDATE the dcache page. This helper is only used for writeback of CODE pages to memory. So there's no value in keeping the dcache lines around. Infact it is risky as a writeback on natural eviction under pressure can cause un-needed writeback with weird issues on aliasing dcache configurations. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* Merge tag 'arc-v3.10-rc1-part2' of ↵Linus Torvalds2013-05-104-51/+279
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc Pull second set of arc arch updates from Vineet Gupta: "Aliasing VIPT dcache support for ARC I'm satisified with testing, specially with fuse which has historically given grief to VIPT arches (ARM/PARISC...)" * tag 'arc-v3.10-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: [TB10x] Remove GENERIC_GPIO ARC: [mm] Aliasing VIPT dcache support 4/4 ARC: [mm] Aliasing VIPT dcache support 3/4 ARC: [mm] Aliasing VIPT dcache support 2/4 ARC: [mm] Aliasing VIPT dcache support 1/4 ARC: [mm] refactor the core (i|d)cache line ops loops ARC: [mm] serious bug in vaddr based icache flush
| * ARC: [mm] Aliasing VIPT dcache support 4/4Vineet Gupta2013-05-092-1/+79
| | | | | | | | | | | | Enforce congruency of userspace shared mappings Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| * ARC: [mm] Aliasing VIPT dcache support 3/4Vineet Gupta2013-05-091-1/+1
| | | | | | | | | | | | Fix the one zillion warnings Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| * ARC: [mm] Aliasing VIPT dcache support 2/4Vineet Gupta2013-05-092-11/+150
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the meat of the series which prevents any dcache alias creation by always keeping the U and K mapping of a page congruent. If a mapping already exists, and other tries to access the page, prev one is flushed to physical page (wback+inv) Essentially flush_dcache_page()/copy_user_highpage() create K-mapping of a page, but try to defer flushing, unless U-mapping exist. When page is actually mapped to userspace, update_mmu_cache() flushes the K-mapping (in certain cases this can be optimised out) Additonally flush_cache_mm(), flush_cache_range(), flush_cache_page() handle the puring of stale userspace mappings on exit/munmap... flush_anon_page() handles the existing U-mapping for anon page before kernel reads it via the GUP path. Note that while not complete, this is enough to boot a simple dynamically linked Busybox based rootfs Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| * ARC: [mm] Aliasing VIPT dcache support 1/4Vineet Gupta2013-05-092-17/+33
| | | | | | | | | | | | | | This preps the low level dcache flush helpers to take vaddr argument in addition to the existing paddr to properly flush the VIPT dcache Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| * ARC: [mm] refactor the core (i|d)cache line ops loopsVineet Gupta2013-05-091-29/+24
| | | | | | | | | | | | | | | | Nothing semantical * simplify the alignement code by using & operation only * rename variables clearly as paddr Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| * ARC: [mm] serious bug in vaddr based icache flushVineet Gupta2013-05-091-1/+1
| | | | | | | | | | | | | | | | | | | | vaddr used to index the cache was clipped from the wrong end, and thus would potentially fail to flush the correct lines. The problem was dorment for so long because up until the recent optimizations it was only used for ptrace break-point only flushes. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* | Merge tag 'arc-v3.10-rc1-part1' of ↵Linus Torvalds2013-05-096-228/+83
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc Pull ARC port updates from Vineet Gupta: "Support for two new platforms based on ARC700: - Abilis TB10x SoC [Chritisian/Pierrick] - Simulator only System-C Model [Mischa] ARC specific MM improvements: - Avoid full TLB flush (ASID increment) on munmap (even single page) - VIPT Cache Flushing improvements + Delayed dcache flush for non-aliasing dcache (big performance boost) + icache flush aliasing agnostic (no need to kill all possible aliases) Others: - Avoid needless rebuild of DTB files for every kernel build - Remove builtin cmdline as that is already provided by DeviceTree/bootargs - Fixing unaligned access emulation corner case - checkpatch fixes [Sachin] - Various fixlets [Noam] - Minor build failures/cleanups" * tag 'arc-v3.10-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (35 commits) ARC: [mm] Lazy D-cache flush (non aliasing VIPT) ARC: [mm] micro-optimize page size icache invalidate ARC: [mm] remove the pessimistic all-alias-invalidate icache helpers ARC: [mm] consolidate icache/dcache sync code ARC: [mm] optimise icache flush for kernel mappings ARC: [mm] optimise icache flush for user mappings ARC: [mm] optimize needless full mm TLB flush on munmap ARC: Add support for nSIM OSCI System C model ARC: [TB10x] Adapt device tree to new compatible string ARC: [TB10x] Add support for TB10x platform ARC: [TB10x] Device tree of TB100 and TB101 Development Kits ARC: Prepare interrupt code for external controllers ARC: Allow embedded arc-intc to be properly placed in DT intc hierarchy ARC: [cmdline] Don't overwrite u-boot provided bootargs ARC: [cmdline] Remove CONFIG_CMDLINE ARC: [plat-arcfpga] defconfig update ARC: unaligned access emulation broken if callee-reg dest of LD/ST ARC: unaligned access emulation error handling consolidation ARC: Debug/crash-printing Improvements ARC: fix typo with clock speed ...
| * ARC: [mm] Lazy D-cache flush (non aliasing VIPT)Vineet Gupta2013-05-072-7/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | flush_dcache_page( ) is MM hook to ensure that a page has consistent views between kernel and userspace. Thus it is called when * kernel writes to a page which at some later point could get mapped to userspace (so kernel mapping needs to be flushed-n-inv) * kernel is about to read from a page with possible userspace mappings (so userspace mappings needs to be made coherent with kernel ones) However for Non aliasing VIPT dcache, any userspace mapping will always be congruent to kernel mapping. Thus d-cache need need not be flushed at all (or delayed indefinitely). The only reason it does need to be flushed is when mapping code pages. Since icache doesn't snoop dcache, those dirty dcache lines need to be written back to memory and icache line invalidated so that icache lines fetch will get the right data. Decent gains on LMBench fork/exec/sh and File I/O micro-benchmarks. (1) FPGA @ 80 MHZ Processor, Processes - times in microseconds - smaller is better ------------------------------------------------------------------------------ Host OS Mhz null null open slct sig sig fork exec sh call I/O stat clos TCP inst hndl proc proc proc --------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- 3.9-rc6-a Linux 3.9.0-r 80 4.79 8.72 66.7 116. 239. 8.39 30.4 4798 14.K 34.K 3.9-rc6-b Linux 3.9.0-r 80 4.79 8.62 65.4 111. 239. 8.35 29.0 3995 12.K 30.K 3.9-rc7-c Linux 3.9.0-r 80 4.79 9.00 66.1 106. 239. 8.61 30.4 2858 10.K 24.K ^^^^ ^^^^ ^^^ File & VM system latencies in microseconds - smaller is better ------------------------------------------------------------------------------- Host OS 0K File 10K File Mmap Prot Page 100fd Create Delete Create Delete Latency Fault Fault selct --------- ------------- ------ ------ ------ ------ ------- ----- ------- ----- 3.9-rc6-a Linux 3.9.0-r 317.8 204.2 1122.3 375.1 3522.0 4.288 20.7 126.8 3.9-rc6-b Linux 3.9.0-r 298.7 223.0 1141.6 367.8 3531.0 4.866 20.9 126.4 3.9-rc7-c Linux 3.9.0-r 278.4 179.2 862.1 339.3 3705.0 3.223 20.3 126.6 ^^^^^ ^^^^^ ^^^^^ ^^^^ (2) Customer Silicon @ 500 MHz (166 MHz mem) ------------------------------------------------------------------------------ Host OS Mhz null null open slct sig sig fork exec sh call I/O stat clos TCP inst hndl proc proc proc --------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- abilis-ba Linux 3.9.0-r 497 0.71 1.38 4.58 12.0 35.5 1.40 3.89 2070 5525 13.K abilis-ca Linux 3.9.0-r 497 0.71 1.40 4.61 11.8 35.6 1.37 3.92 1411 4317 10.K ^^^^ ^^^^ ^^^ Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| * ARC: [mm] micro-optimize page size icache invalidateVineet Gupta2013-05-071-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | start address is already page aligned and size is const PAGE_SIZE, thus fixups for alignment not needed in generated code. bloat-o-meter vmlinux-mm5 vmlinux add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-32 (-32) function old new delta __inv_icache_page 82 50 -32 Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| * ARC: [mm] remove the pessimistic all-alias-invalidate icache helpersVineet Gupta2013-05-071-184/+17
| | | | | | | | | | | | No users of this code anymore - so RIP ! Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| * ARC: [mm] consolidate icache/dcache sync codeVineet Gupta2013-05-071-16/+16
| | | | | | | | | | | | | | | | | | | | Now that we have same helper used for all icache invalidates (i.e. vaddr+paddr based exact line invalidate), consolidate the open coded calls into one place. Also rename flush_icache_range_vaddr => __sync_icache_dcache Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| * ARC: [mm] optimise icache flush for kernel mappingsVineet Gupta2013-05-071-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change continues the theme from prev commit - this time icache handling for kernel's own code modification (vmalloc: loadable modules, breakpoints for kprobes/kgdb...) flush_icache_range() calls the CDU icache helper with vaddr to enable exact line invalidate. For a true kernel-virtual mapping, the vaddr is actually virtual hence valid as index into cache. For kprobes breakpoint however, the vaddr arg is actually paddr - since that's how normal kernel is mapped in ARC memory map. This implies that CDU will use the same addr for indexing as for tag match - which is fine since kernel code would only have that "implicit" mapping and none other. This should speed up module loading significantly - specially on default ARC700 icache configurations (32k) which alias. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| * ARC: [mm] optimise icache flush for user mappingsVineet Gupta2013-05-072-14/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ARC icache doesn't snoop dcache thus executable pages need to be made coherent before mapping into userspace in flush_icache_page(). However ARC700 CDU (hardware cache flush module) requires both vaddr (index in cache) as well as paddr (tag match) to correctly identify a line in the VIPT cache. A typical ARC700 SoC has aliasing icache, thus the paddr only based flush_icache_page() API couldn't be implemented efficiently. It had to loop thru all possible alias indexes and perform the invalidate operation (ofcourse the cache op would only succeed at the index(es) where tag matches - typically only 1, but the cost of visiting all the cache-bins needs to paid nevertheless). Turns out however that the vaddr (along with paddr) is available in update_mmu_cache() hence better suits ARC icache flush semantics. With both vaddr+paddr, exactly one flush operation per line is done. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>