Commit Graph

252 Commits

Author SHA1 Message Date
Vineet Gupta d091fcb97f ARC: MMUv4 preps/2 - Reshuffle PTE bits
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>
2013-08-30 10:19:12 +05:30
Vineet Gupta 64b703ef27 ARC: MMUv4 preps/1 - Fold PTE K/U access flags
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 a950549c67
   "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>
2013-08-29 17:51:36 +05:30
Vineet Gupta 4b06ff35fb ARC: Code cosmetics (Nothing semantical)
* 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>
2013-08-29 17:51:15 +05:30
Grant Likely a1727da599 of: consolidate definition of early_init_dt_alloc_memory_arch()
Most architectures use the same implementation. Collapse the common ones
into a single weak function that can be overridden.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
2013-08-28 21:18:32 +01:00
Grant Likely 8be137f266 Linux 3.11-rc7
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Merge tag 'v3.11-rc7' into devicetree/next

Linux 3.11-rc7
2013-08-28 20:18:13 +01:00
Vineet Gupta fce16bc35a ARC: Entry Handler tweaks: Optimize away redundant IRQ_DISABLE_SAVE
In the exception return path, for both U/K cases, intr are already
disabled (for various existing reasons). So when we drop down to
@restore_regs, we need not redo that.

There was subtle issue - when intr were NOT being disabled for
ret-to-kernel-but-no-preemption case - now fixed by moving the
IRQ_DISABLE further up in @resume_kernel_mode.

So what do we gain:

* Shaves off a few insn in return path.

* Eliminates the need for IRQ_DISABLE_SAVE assembler macro for ARCv2
  hence allows for entry code sharing.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-26 09:40:25 +05:30
Vineet Gupta 37f3ac498c ARC: Exception Handlers Code consolidation
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>
2013-08-26 09:40:25 +05:30
Vineet Gupta fe240f11cd ARC: Add some .gitignore entries
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-26 09:40:24 +05:30
Joern Rennecke b0f55f2a1a ARC: [lib] strchr breakage in Big-endian configuration
For a search buffer, 2 byte aligned, strchr() was returning pointer
outside of buffer (buf - 1)

------------->8----------------
    // Input buffer (default 4 byte aigned)
    char *buffer = "1AA_";

    // actual search start (to mimick 2 byte alignment)
    char *current_line = &(buffer[2]);

    // Character to search for
    char c = 'A';

    char *c_pos = strchr(current_line, c);

    printf("%s\n", c_pos) --> 'AA_' as oppose to 'A_'
------------->8----------------

Reported-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Debugged-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Cc: <stable@vger.kernel.org> # [3.9 and 3.10]
Cc: Noam Camus <noamc@ezchip.com>
Signed-off-by: Joern Rennecke  <joern.rennecke@embecosm.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-24 11:24:53 -07:00
Vineet Gupta 4ffd9e2c4d ARC: SMP build breakage
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-07-26 15:34:22 -07:00
Santosh Shilimkar 374d5c9964 of: Specify initrd location using 64-bit
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>
2013-07-24 11:10:01 +01:00
Linus Torvalds 8f041e6ca1 Couple of Platform updates (Device Tree files primarily) given that the
corresponding drivers (net/ethernet/arc/*, irqctl/irq-tb10x.c) have now
 been merged into your tree.
 
 Ideally these shd have been part of same submissions, oh well...
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Merge tag 'arc-v3.11-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull second set of ARC architecture updates from Vineet Gupta:
 "Couple of Platform updates (Device Tree files primarily) given that
  the corresponding drivers (net/ethernet/arc/*, irqctl/irq-tb10x.c)
  have now been merged into your tree.

  Ideally these shd have been part of same submissions, oh well..."

* tag 'arc-v3.11-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: [TB10x] Updates for irqchip driver
  ARC: [plat-arcfpga] Enable arc_emac for ARCAngle4 Board
2013-07-10 10:11:26 -07:00
Johannes Weiner 609838cfed mm: invoke oom-killer from remaining unconverted page fault handlers
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>
2013-07-09 10:33:20 -07:00
Linus Torvalds 98f486f18d Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 - new drivers: Kontron PLD, Wondermedia VT
 - mv64xxx driver gained sun4i support and a bigger cleanup
 - duplicate driver 'intel-mid' removed
 - added generic device tree binding for sda holding time (and
   designware driver already uses it)
 - we tried to allow driver probing with only device tree and no i2c
   ids, but I had to revert it because of side effects.  Needs some
   rethinking.
 - driver bugfixes, cleanups...

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (34 commits)
  i2c-designware: use div_u64 to fix link
  i2c: Kontron PLD i2c bus driver
  i2c: iop3xxx: fix build failure after waitqueue changes
  i2c-designware: make SDA hold time configurable
  i2c: mv64xxx: Set bus frequency to 100kHz if clock-frequency is not provided
  i2c: imx: allow autoloading on dt ids
  i2c: mv64xxx: Fix transfer error code
  i2c: i801: SMBus patch for Intel Coleto Creek DeviceIDs
  i2c: omap: correct usage of the interrupt enable register
  i2c-pxa: prepare clock before use
  Revert "i2c: core: make it possible to match a pure device tree driver"
  i2c: nomadik: allocate adapter number dynamically
  i2c: nomadik: support elder Nomadiks
  i2c: mv64xxx: Add Allwinner sun4i compatible
  i2c: mv64xxx: make the registers offset configurable
  i2c: mv64xxx: Add macros to access parts of registers
  i2c: vt8500: Add support for I2C bus on Wondermedia SoCs
  i2c: designware: fix race between subsequent xfers
  i2c: bfin-twi: Read and write the FIFO in loop
  i2c: core: make it possible to match a pure device tree driver
  ...
2013-07-04 14:02:09 -07:00
Linus Torvalds e61aca5158 Merge branch 'kconfig-diet' from Dave Hansen
Merge Kconfig menu diet patches from Dave Hansen:
 "I think the "Kernel Hacking" menu has gotten a bit out of hand.  It is
  over 120 lines long on my system with everything enabled and options
  are scattered around it haphazardly.

        http://sr71.net/~dave/linux/kconfig-horror.png

  Let's try to introduce some sanity.  This set takes that 120 lines
  down to 55 and makes it vastly easier to find some things.  It's a
  start.

  This set stands on its own, but there is plenty of room for follow-up
  patches.  The arch-specific debug options still end up getting stuck
  in the top-level "kernel hacking" menu.  OPTIMIZE_INLINING, for
  instance, could obviously go in to the "compiler options" menu, but
  the fact that it is defined in arch/ in a separate Kconfig file keeps
  it on its own for the moment.

  The Signed-off-by's in here look funky.  I changed employers while
  working on this set, so I have signoffs from both email addresses"

* emailed patches from Dave Hansen <dave@sr71.net>:
  hang and lockup detection menu
  kconfig: consolidate printk options
  group locking debugging options
  consolidate compilation option configs
  consolidate runtime testing configs
  order memory debugging Kconfig options
  consolidate per-arch stack overflow debugging options
2013-07-04 11:25:51 -07:00
Dave Hansen d1a1dc0be8 consolidate per-arch stack overflow debugging options
Original posting:

	http://lkml.kernel.org/r/20121214184202.F54094D9@kernel.stglabs.ibm.com

Several architectures have similar stack debugging config options.
They all pretty much do the same thing, some with slightly
differing help text.

This patch changes the architectures to instead enable a Kconfig
boolean, and then use that boolean in the generic Kconfig.debug
to present the actual menu option.  This removes a bunch of
duplication and adds consistency across arches.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com> [for tile]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-04 11:25:39 -07:00
Linus Torvalds 7f0ef0267e Merge branch 'akpm' (updates from Andrew Morton)
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
  ...
2013-07-03 17:12:13 -07:00
Jiang Liu de35e1b828 mm/ARC: prepare for removing num_physpages and simplify mem_init()
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>
2013-07-03 16:07:35 -07:00
Jiang Liu 0c98853473 mm: concentrate modification of totalram_pages into the mm core
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>
2013-07-03 16:07:33 -07:00
Jiang Liu dbe67df4ba mm: enhance free_reserved_area() to support poisoning memory with zero
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>
2013-07-03 16:07:32 -07:00
Jiang Liu 11199692d8 mm: change signature of free_reserved_area() to fix building warnings
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>
2013-07-03 16:07:32 -07:00
Linus Torvalds 76d3f4c27d ARC changes for 3.11
Highlights of changes:
 
 -Continuation of ARC MM changes from 3.10 including
    zero page optimization;
    Setting pagecache pages dirty by default;
    Non executable stack by default;
    Reducing dcache flushes for aliasing VIPT config
 
 -Long overdue rework of pt_regs machinery - removing the unused word gutters
  and adding ECR register to baseline (helps cleanup lot of low level code)
 
 -Support for ARC gcc 4.8
 
 -Few other preventive fixes, cosmetics, usage of Kconfig helper..
 
 The diffstat is larger than normal primarily because of arcregs.h header split
 as well as beautification of macros in entry.h
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Merge tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull first batch of ARC changes from Vineet Gupta:
 "There's a second bunch to follow next week - which depends on commits
  on other trees (irq/net).  I'd have preferred the accompanying ARC
  change via respective trees, but it didn't workout somehow.

  Highlights of changes:

   - Continuation of ARC MM changes from 3.10 including

       zero page optimization
       Setting pagecache pages dirty by default
       Non executable stack by default
       Reducing dcache flushes for aliasing VIPT config

   - Long overdue rework of pt_regs machinery - removing the unused word
     gutters and adding ECR register to baseline (helps cleanup lot of
     low level code)

   - Support for ARC gcc 4.8

   - Few other preventive fixes, cosmetics, usage of Kconfig helper..

  The diffstat is larger than normal primarily because of arcregs.h
  header split as well as beautification of macros in entry.h"

* tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (32 commits)
  ARC: warn on improper stack unwind FDE entries
  arc: delete __cpuinit usage from all arc files
  ARC: [tlb-miss] Fix bug with CONFIG_ARC_DBG_TLB_MISS_COUNT
  ARC: [tlb-miss] Extraneous PTE bit testing/setting
  ARC: Adjustments for gcc 4.8
  ARC: Setup Vector Table Base in early boot
  ARC: Remove explicit passing around of ECR
  ARC: pt_regs update #5: Use real ECR for pt_regs->event vs. synth values
  ARC: stop using pt_regs->orig_r8
  ARC: pt_regs update #4: r25 saved/restored unconditionally
  ARC: K/U SP saved from one location in stack switching macro
  ARC: Entry Handler tweaks: Simplify branch for in-kernel preemption
  ARC: Entry Handler tweaks: Avoid hardcoded LIMMS for ECR values
  ARC: Increase readability of entry handlers
  ARC: pt_regs update #3: Remove unused gutter at start of callee_regs
  ARC: pt_regs update #2: Remove unused gutter at start of pt_regs
  ARC: pt_regs update #1: Align pt_regs end with end of kernel stack page
  ARC: pt_regs update #0: remove kernel stack canary
  ARC: [mm] Remove @write argument to do_page_fault()
  ARC: [mm] Make stack/heap Non-executable by default
  ...
2013-07-03 11:09:27 -07:00
Al Viro e77e430033 more open-coded file_inode() calls
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:21 +04:00
Al Viro 40d158e618 consolidate io_remap_pfn_range definitions
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:46:35 +04:00
Christian Ruppert 723e2b801d ARC: [TB10x] Updates for irqchip driver
Device tree and Kconfig updates for irqchip driver.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-28 15:07:42 +05:30
Alexey Brodkin d0e63ed941 ARC: [plat-arcfpga] Enable arc_emac for ARCAngle4 Board
* Add arc_emac to DeviceTree DT description
  "Documentation/devicetree/bindings/net/arc_emac.txt".

* Update defconfig correspondingly

[vgupta: tweaked changelog]
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-28 15:07:20 +05:30
Vineet Gupta baadb8fd0c ARC: warn on improper stack unwind FDE entries
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:37:59 +05:30
Paul Gortmaker ce7599567e arc: delete __cpuinit usage from all arc files
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>
2013-06-27 14:37:58 +05:30
Vineet Gupta dc81df2440 ARC: [tlb-miss] Fix bug with CONFIG_ARC_DBG_TLB_MISS_COUNT
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>
2013-06-27 14:37:57 +05:30
Vineet Gupta c3e757a77c ARC: [tlb-miss] Extraneous PTE bit testing/setting
* 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>
2013-06-27 14:37:57 +05:30
Vineet Gupta 5a45da02cf ARC: Adjustments for gcc 4.8
* DWARF unwinder related
  + Force DWARF2 compliant .debug_frame (gcc 4.8 defaults to DWARF4
    which kernel unwinder can't grok).
  + Discard the additional .eh_frame generated
  + Discard the dwarf4 debug info generated by -gdwarf-2 for normal
    no debug case

* 4.8 already uses arc600 multilibs for -mno-mpy

* switch to using uclibc compiler (to get -mmedium-calls and -mno-sdata)
  and also since buildroot can only use 1 toolchain

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:35:32 +05:30
Christian Ruppert 9803f86894 i2c-designware: make SDA hold time configurable
This patch makes the SDA hold time configurable through device tree.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com> for arch/arc bits
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-26 16:02:06 +02:00
Vineet Gupta 05b016ecf5 ARC: Setup Vector Table Base in early boot
Otherwise early boot exceptions such as instructions errors due to
configuration mismatch between kernel and hardware go off to la-la land,
as opposed to hitting the handler and panic()'ing properly.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-26 15:30:51 +05:30
Vineet Gupta 38a9ff6d24 ARC: Remove explicit passing around of ECR
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>
2013-06-26 15:30:50 +05:30
Vineet Gupta 502a0c775c ARC: pt_regs update #5: Use real ECR for pt_regs->event vs. synth values
pt_regs->event was set with artificial values to identify the low level
system event (syscall trap / breakpoint trap / exceptions / interrupts)

With r8 saving out of the way, the full word can be used to save real
ECR (Exception Cause Register) which helps idenify the event naturally,
including additional info such as cause code, param.
Only for Interrupts, where ECR is not applicable, do we resort to
synthetic non ECR values.

SAVE_ALL_TRAP/EXCEPTIONS can now be merged as they both use ECR with
different runtime values.

The ptrace helpers now use the sub-fields of ECR to distinguish the
events (e.g. vector 0x25 is trap, param 0 is syscall...)

The following benefits will follow:

(1) This centralizes the location of where ECR is saved and will allow
    the cleanup of task->thread.cause_code ECR placeholder which is set
    in non-uniform way. Then ARC VM code can safely rely on it being
    there for purpose of finer grained VM_EXEC dcache flush (based on
    exec fault: I-TLB Miss)

(2) Further, ECR being passed around from low level handlers as arg can
    be eliminated as it is part of standard reg-file in pt_regs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-26 14:04:48 +05:30
Vineet Gupta 352c1d95e3 ARC: stop using pt_regs->orig_r8
Historically, pt_regs have had orig_r8, an overloaded container for
  (1) backup copy of r8 (syscall number Trap Exceptions)
  (2) additional system state: (syscall/Exception/Interrupt)

There is no point in keeping (1) since syscall number is never clobbered
in-place, in pt_regs, unlike r0 which duals as first syscall arg as well
as syscall return value and in case of syscall restart, the orig arg0
needs restoring (from orig_r0)  after having been updated in-place with
syscall ret value.

This further paves way to convert (2) to contain ECR itself (rather than
current madeup values)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:26 +05:30
Vineet Gupta 359105bdb0 ARC: pt_regs update #4: r25 saved/restored unconditionally
(This is a VERY IMP change for low level interrupt/exception handling)

-----------------------------------------------------------------------
WHAT
-----------------------------------------------------------------------
* User 25 now saved in pt_regs->user_r25 (vs. tsk->thread_info.user_r25)

* This allows Low level interrupt code to unconditionally save r25
  (vs. the prev version which would only do it for U->K transition).
  Ofcourse for nested interrupts, only the pt_regs->user_r25 of
  bottom-most frame is useful.

* simplifies the interrupt prologue/epilogue

* Needed for ARCv2 ISA code and done here to keep design similar with
  ARCompact event handling

-----------------------------------------------------------------------
WHY
-------------------------------------------------------------------------
With CONFIG_ARC_CURR_IN_REG, r25 is used to cache "current" task pointer
in kernel mode. So when entering kernel mode from User Mode
- user r25 is specially safe-kept (it being a callee reg is NOT part of
  pt_regs which are saved by default on each interrupt/trap/exception)
- r25 loaded with current task pointer.

Further, if interrupt was taken in kernel mode, this is skipped since we
know that r25 already has valid "current" pointer.

With 2 level of interrupts in ARCompact ISA, detecting this is difficult
but still possible, since we could be in kernel mode but r25 not already saved
(in fact the stack itself might not have been switched).

A. User mode
B. L1 IRQ taken
C. L2 IRQ taken (while on 1st line of L1 ISR)

So in #C, although in kernel mode, r25 not saved (infact SP not
switched at all)

Given that ARcompact has manual stack switching, we could use a bit of
trickey - The low level code would make sure that SP is only set to kernel
mode value at the very end (after saving r25). So a non kernel mode SP,
even if in kernel mode, meant r25 was NOT saved.

The same paradigm won't work in ARCv2 ISA since SP is auto-switched so
it's setting can't be delayed/constrained.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:25 +05:30
Vineet Gupta ba3558c772 ARC: K/U SP saved from one location in stack switching macro
This paves way for further simplifications.

There's an overhead of 1 insn for the non-common case of interrupt taken
from kernel mode.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:25 +05:30
Vineet Gupta 147aece29b ARC: Entry Handler tweaks: Simplify branch for in-kernel preemption
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:24 +05:30
Vineet Gupta 1898a959b7 ARC: Entry Handler tweaks: Avoid hardcoded LIMMS for ECR values
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:23 +05:30
Vineet Gupta 3ebedbb2fd ARC: Increase readability of entry handlers
* use artificial PUSH/POP contructs for CORE Reg save/restore to stack
* use artificial PUSHAX/POPAX contructs for Auxiliary Space regs
* macro'ize multiple copies of callee-reg-save/restore (SAVE_R13_TO_R24)
* use BIC insn for inverse-and operation

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:23 +05:30
Vineet Gupta 16f9afe651 ARC: pt_regs update #3: Remove unused gutter at start of callee_regs
This is trickier than prev two:

* context switching code saves kernel mode callee regs in the format of
  struct callee_regs thus needs adjustment. This also reduces the height
  of topmost kernel stack frame by 1 word.

* Since kernel stack unwinder is sensitive to height of topmost kernel
  stack frame, that needs a word of adjustment too.

ptrace needs a bit of updating since pt_regs now diverges from
user_regs_struct.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:22 +05:30
Vineet Gupta 2fa919045b ARC: pt_regs update #2: Remove unused gutter at start of pt_regs
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:22 +05:30
Vineet Gupta 283237a04f ARC: pt_regs update #1: Align pt_regs end with end of kernel stack page
Historically, pt_regs would end at offset of 1 word from end of stack
page.

        -----------------  -> START of page (task->stack)
        |               |
        | thread_info   |
        -----------------
        |               |
   ^    ~               ~
   |    ~               ~
   |    |               |
   |    |               | <---- pt_regs used to END here
        -----------------
        | 1 word GUTTER |
        ----------------- -> End of page (START of kernel stack)

This required special "one-off" considerations in low level code.

The root cause is very likely assumption of "empty" SP by the original
ARC kernel hackers, despite ARC700 always been "full" SP.

So finally RIP one word gutter !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:21 +05:30
Vineet Gupta bed30976e7 ARC: pt_regs update #0: remove kernel stack canary
This stack slot is going to be used in subsequent commits

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:21 +05:30
Vineet Gupta 3e1ae44188 ARC: [mm] Remove @write argument to do_page_fault()
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>
2013-06-22 19:23:20 +05:30
Vineet Gupta 3abc944802 ARC: [mm] Make stack/heap Non-executable by default
1. For VM_EXEC based delayed dcache/icache flush, reduces the number of
   flushes.

2. Makes this security feature ON by default rather than OFF before.

3. Applications can use mprotect() to selectively override this.

4. ELF binaries have a GNU_STACK segment which can easily override the
   kernel default permissions.
   For nested-functions/trampolines, gcc already auto-enables executable
   stack in elf. Others needing this can use -Wl,-z,execstack option.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:20 +05:30
Vineet Gupta 2ed21dae02 ARC: [mm] Assume pagecache page dirty by default
Similar to ARM/SH

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:19 +05:30
Vineet Gupta fedf5b9baf ARC: [mm] optimise VIPT dcache aliasing 2/x
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>
2013-06-22 19:23:19 +05:30
Vineet Gupta 5971bc719d ARC: [mm] optimise VIPT dcache aliasing 1/x
flush_cache_page() - kills icache only if page is executable

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:18 +05:30
Vineet Gupta 29b93c68bf ARC: [mm] Zero page optimization
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:18 +05:30
Alexey Brodkin 2f9e99618f ARC: make dcache VIPT aliasing support dependant on dcache
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:17 +05:30
Vineet Gupta 336e199e9c ARC: No-op full icache flush if !CONFIG_ARC_HAS_ICACHE
Also remove extraneous irq disabling in flush_cache_all() callstack

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:22:42 +05:30
Vineet Gupta 3049918660 ARC: cache detection code bitrot
* 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>
2013-06-22 13:46:43 +05:30
Vineet Gupta 6546415226 ARC: Reduce Code for ECR printing
Cause codes are same for D-TLB-Miss and Prot-V

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:42 +05:30
Vineet Gupta da1677b02d ARC: Disintegrate arcregs.h
* 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>
2013-06-22 13:46:42 +05:30
Vineet Gupta 18437347b9 ARC: More code beautification with IS_ENABLED()
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:42 +05:30
Vineet Gupta 8235703e10 ARC: Use kconfig helper IS_ENABLED() to get rid of defines.h
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:42 +05:30
Mischa Jonker ba5afadb11 ARC: [plat-arcfpga] Fix build breakage when !CONFIG_ARC_SERIAL
This fixes the following:
- CONFIG_ARC_SERIAL_BAUD is only defined when CONFIG_SERIAL_ARC is defined.
  Make sure that it isn't referenced otherwise.
- There is no use for initializing arc_uart_info[] when CONFIG_SERIAL_ARC is
  not defined.

[vgupta: tweaked changelog title, used IS_ENABLED() kconfig helper]
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:41 +05:30
Vineet Gupta 7bb66f6e6e ARC: lazy dcache flush broke gdb in non-aliasing configs
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>
2013-05-25 14:15:55 +05:30
Vineet Gupta 006dfb3c9c ARC: Use enough bits for determining page's cache color
The current code uses 2 bits for determining page's dcache color, thus
sorting pages into 4 bins, whereas the aliasing dcache really has 2 bins
(8k page, 64k dcache - 4 way-set-assoc).
This can cause extraneous flushes - e.g. color 0 and 2.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-23 14:25:09 +05:30
Vineet Gupta 3e87974dec ARC: Brown paper bag bug in macro for checking cache color
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>
2013-05-23 14:24:52 +05:30
Vineet Gupta a950549c67 ARC: copy_(to|from)_user() to honor usermode-access permissions
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>
2013-05-23 10:33:03 +05:30
Vineet Gupta f538881cc6 ARC: [mm] Prevent stray dcache lines after__sync_icache_dcach()
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>
2013-05-23 10:26:33 +05:30
Christian Ruppert 7d19273cd0 ARC: [TB10x] Remove redundant abilis,simple-pinctrl mechanism
The TB10x platform port includes a custom mechanism using to set up
default pin controller configurations using abilis,simple-default
pin configurations of nodes compatible with abilis,simple-pinctrl. This
mechanism is redundant with the Linux standard "default" pin
configuration, see commit ab78029ecc
"drivers/pinctrl: grab default handles from device core".
This patch removes the TB10x custom mechanism in favour of the Linux
standard.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-15 10:12:03 +05:30
Linus Torvalds 6019958d14 Aliasing VIPT dcache support for ARC
I'm satisified with testing, specially with fuse which has historically given
 grief to VIPT arches (ARM/PARISC...)
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Merge tag 'arc-v3.10-rc1-part2' of 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
2013-05-10 07:24:14 -07:00
Vineet Gupta e7d5bab5ef ARC: [TB10x] Remove GENERIC_GPIO
This tracks Alexandre Courbot's mainline GPIO rework

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
2013-05-10 09:50:33 +05:30
Linus Torvalds e30f419245 ARC port updates for Linux 3.10 (part 1)
* 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
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Merge tag 'arc-v3.10-rc1-part1' of 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
  ...
2013-05-09 14:36:27 -07:00
Vineet Gupta 5bba49f539 ARC: [mm] Aliasing VIPT dcache support 4/4
Enforce congruency of userspace shared mappings

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 22:00:57 +05:30
Vineet Gupta de2a852cc0 ARC: [mm] Aliasing VIPT dcache support 3/4
Fix the one zillion warnings

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 22:00:57 +05:30
Vineet Gupta 4102b53392 ARC: [mm] Aliasing VIPT dcache support 2/4
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>
2013-05-09 21:59:46 +05:30
Vineet Gupta 6ec18a81b2 ARC: [mm] Aliasing VIPT dcache support 1/4
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>
2013-05-09 21:53:16 +05:30
Vineet Gupta a690984d60 ARC: [mm] refactor the core (i|d)cache line ops loops
Nothing semantical
* simplify the alignement code by using & operation only
* rename variables clearly as paddr

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 14:18:50 +05:30
Vineet Gupta c917a36f5f ARC: [mm] serious bug in vaddr based icache flush
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>
2013-05-09 13:45:12 +05:30
Vineet Gupta eacd0e950d ARC: [mm] Lazy D-cache flush (non aliasing VIPT)
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>
2013-05-07 19:08:15 +05:30
Vineet Gupta 764531cc5a ARC: [mm] micro-optimize page size icache invalidate
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>
2013-05-07 19:08:14 +05:30
Vineet Gupta 7f250a0fa1 ARC: [mm] remove the pessimistic all-alias-invalidate icache helpers
No users of this code anymore - so RIP !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:13 +05:30
Vineet Gupta 94bad1afee ARC: [mm] consolidate icache/dcache sync code
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>
2013-05-07 19:08:13 +05:30
Vineet Gupta 7586bf7286 ARC: [mm] optimise icache flush for kernel mappings
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>
2013-05-07 19:08:12 +05:30
Vineet Gupta 24603fdd19 ARC: [mm] optimise icache flush for user mappings
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>
2013-05-07 19:08:12 +05:30
Vineet Gupta 8d56bec2f2 ARC: [mm] optimize needless full mm TLB flush on munmap
munmap ends up calling tlb_flush() which for ARC was flushing the entire
TLB unconditionally (by moving the MMU to a new ASID)

do_munmap
  unmap_region
    unmap_vmas
      unmap_single_vma
         unmap_page_range
            tlb_start_vma
            zap_pud_range
            tlb_end_vma()
  tlb_finish_mmu
    tlb_flush()  ---> unconditional flush_tlb_mm()

So even a single page munmap, a frequent operation when uClibc dynamic
linker (ldso) is loading the dependent shared libraries, would move the
the ASID multiple times - needlessly invalidating the pre-faulted TLB
entries (and increasing the rate of ASID wraparound + full TLB flush).

This is now optimised to only be called if tlb->full_mm (which means
for exit/execve) cases only. And for those cases, flush_tlb_mm() is
already optimised to be a no-op for mm->mm_users == 0.

So essentially there are no mmore full mm flushes - except for fork which
anyhow needs it for properly COW'ing parent address space.

munmap now needs to do TLB range flush, which is implemented with
tlb_end_vma()

Results
-------
1. ASID now consistenly moves by 4 during a simple ls (as opposed to 5 or
   7 before).

2. LMBench microbenchmark also shows improvements

Basic system parameters
------------------------------------------------------------------------------
Host                 OS Description              Mhz  tlb  cache  mem scal
                                                     pages line   par load
                                                           bytes
--------- ------------- ----------------------- ---- ----- ----- ------ ----
3.9-rc5-0 Linux 3.9.0-r 3.9-rc5-0404-gcc-4.4-ba   80     8    64 1.1000 1
3.9-rc5-0 Linux 3.9.0-r 3.9-rc5-0405-avoid-full   80     8    64 1.1200 1

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-rc5-0 Linux 3.9.0-r   80 4.81 8.69 68.6 118. 239. 8.53 31.6 4839 13.K 34.K
3.9-rc5-0 Linux 3.9.0-r   80 4.46 8.36 53.8 91.3 223. 8.12 24.2 4725 13.K 33.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-rc5-0 Linux 3.9.0-r  314.7  223.2 1054.9  390.2  3615.0 1.590 20.1 126.6
3.9-rc5-0 Linux 3.9.0-r  265.8  183.8 1014.2  314.1  3193.0 6.910 18.8 110.4

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:44:00 +05:30
Mischa Jonker a92a5d0dce ARC: Add support for nSIM OSCI System C model
This adds support for an ARC Virtual Platform. This platform is based on the
System C standard promoted by the OSCI (Open System C Initiative) and uses
nSIM to simulate the ARC CPU core itself.

Users can build a virtual SoC by combining System C models of peripherals
and CPU cores.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:44:00 +05:30
Christian Ruppert 0dfad77d0a ARC: [TB10x] Adapt device tree to new compatible string
The original device tree was written using a slightly different
implementation of the fixed-factor-clock device tree binding. The
compatible string must be modified in order to be compatible with the
new implementation.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:59 +05:30
Christian Ruppert 072eb69390 ARC: [TB10x] Add support for TB10x platform
Infrastructure required to make the Linux kernel compile and boot on the
Abilis Systems TB10x series of SOCs based on ARC700 CPUs:
  - Kmake related files (Kconfig, Makefile, tb10x_defconfig)
  - TB10x platform initialisation

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:59 +05:30
Christian Ruppert 2eb9504bcc ARC: [TB10x] Device tree of TB100 and TB101 Development Kits
These are the device tree files for the Abilis Systems TB100 and TB101 ICs and
their respective development kit PCBs. These files are committed in preparation
of the following patch set which adds support for these chips to the ARC
platform.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:58 +05:30
Christian Ruppert a37cdacc9b ARC: Prepare interrupt code for external controllers
This patch adds some room for CPU-external interrupt controllers in the
Linux interrupt space. Until now, only the 32 CPU internal interrupt lines
were supported which does not allow for external interrupt controllers such
as GPIO modules etc.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:58 +05:30
Vineet Gupta c93d8b8c78 ARC: Allow embedded arc-intc to be properly placed in DT intc hierarchy
arc-intc is initialized in arc common code as it is applicable to all
platforms. However platforms with their own external intc still need to
refer to it for correct DT interrupt tree hierarchy setup,

e.g.
static struct of_device_id __initdata tb10x_irq_ids[] = {
	{ .compatible = "snps,arc700-intc", .data = dummy_init_irq },
	{ .compatible = "abilis,tb10x_ictl", .data = tb10x_init_irq },
	{},
};

The fix is to use the generic irqchip framework to tie all irqchips in
a special linker section and then call irqchip_init() which calls the
DT of_irq_init() for all the intc in one go.

That way the platform code need not be aware of arc-intc at all.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:57 +05:30
Vineet Gupta 9593a933d5 ARC: [cmdline] Don't overwrite u-boot provided bootargs
The existing code was wrong on several counts:

* uboot provided bootargs were copied into @boot_command_line, only to
  be over-written by setup_machine_fdt(), effectively lost

* @cmdline_p returned by setup_arch() to start_kernel() didn't include
  the DT /bootargs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:57 +05:30
Vineet Gupta 6971881f2a ARC: [cmdline] Remove CONFIG_CMDLINE
Given that DeviceTree /bootargs can provide similar functionality,
no point in providing duplicate infrastructure.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:56 +05:30
Vineet Gupta 330db3330a ARC: [plat-arcfpga] defconfig update
* Allow initramfs path to be symlink
* CONFIG_PREEMPT be default

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:56 +05:30
Vineet Gupta ce147c7445 ARC: unaligned access emulation broken if callee-reg dest of LD/ST
The fixup code correctly updates the callee-regs on stack, but
fails to unwind it into actual register file. Thus userspace won't see
the update.

Reported-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:55 +05:30
Vineet Gupta c723ea4620 ARC: unaligned access emulation error handling consolidation
If CONFIG_ARC_MISALIGN_ACCESS is not enabled, or if the fixup fails,
call the same error handler: same signal/si_code to user (SIGBUS)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:55 +05:30
Vineet Gupta bd3c8b11ec ARC: Debug/crash-printing Improvements
* Remove the line-break between scratch/callee-regs (sneaked in when we
  converted from printk to pr_*

* Use %pS to print the symbol names of faulting PC (ret pseudo register)
  and BLINK (call return register)

* Don't print user-vma for a kernel crash (only do it for
  print-fatal-signals based regfile dump)

* Verbose print the Interrupt/Exception Enable/Active state

* for main executable link address is 0x10000 based (vs. 0) thus offset
  of faulting PC needs to be adjusted

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:54 +05:30
Noam Camus 68e4790ec4 ARC: fix typo with clock speed
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:54 +05:30
Noam Camus e3edeb67fb ARC: Respect the cpu_id passed for fetching correct cpu info
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:54 +05:30
Alexander Shiyan 0e82284514 ARC: Remove non existent refs to GENERIC_KERNEL_EXECVE & GENERIC_KERNEL_THREAD
This tracks mainline commit ae903caae2 "Bury the conditionals from
kernel_thread/kernel_execve series" which we missed out as ARC port was
not yet mainline.

[vgupta: commit log modified]

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:53 +05:30
Vineet Gupta 681a90ffe8 arc, print-fatal-signals: reduce duplicated information
After the recent generic debug info on dump_stack() and friends, arc
is printing duplicate information on debug dumps.

 [ARCLinux]$ ./crash
 crash/50: potentially unexpected fatal signal 11.	<-- [1]
 /sbin/crash, TGID 50					<-- [2]
 Pid: 50, comm: crash Not tainted 3.9.0-rc4+ #132 	<-- [3]
 ...

Remove them.

[tj@kernel.org: updated patch desc]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
Tejun Heo a43cb95d54 dump_stack: unify debug information printed by show_regs()
show_regs() is inherently arch-dependent but it does make sense to print
generic debug information and some archs already do albeit in slightly
different forms.  This patch introduces a generic function to print debug
information from show_regs() so that different archs print out the same
information and it's much easier to modify what's printed.

show_regs_print_info() prints out the same debug info as dump_stack()
does plus task and thread_info pointers.

* Archs which didn't print debug info now do.

  alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
  metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
  um, xtensa

* Already prints debug info.  Replaced with show_regs_print_info().
  The printed information is superset of what used to be there.

  arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86

* s390 is special in that it used to print arch-specific information
  along with generic debug info.  Heiko and Martin think that the
  arch-specific extra isn't worth keeping s390 specfic implementation.
  Converted to use the generic version.

Note that now all archs print the debug info before actual register
dumps.

An example BUG() dump follows.

 kernel BUG at /work/os/work/kernel/workqueue.c:4841!
 invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7
 Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
 RIP: 0010:[<ffffffff8234a07e>]  [<ffffffff8234a07e>] init_workqueues+0x4/0x6
 RSP: 0000:ffff88007c861ec8  EFLAGS: 00010246
 RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001
 RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a
 RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Stack:
  ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650
  0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
  ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760
 Call Trace:
  [<ffffffff81000312>] do_one_initcall+0x122/0x170
  [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  [<ffffffff81c4776e>] kernel_init+0xe/0xf0
  [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  ...

v2: Typo fix in x86-32.

v3: CPU number dropped from show_regs_print_info() as
    dump_stack_print_info() has been updated to print it.  s390
    specific implementation dropped as requested by s390 maintainers.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>		[tile bits]
Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
Tejun Heo 196779b9b4 dump_stack: consolidate dump_stack() implementations and unify their behaviors
Both dump_stack() and show_stack() are currently implemented by each
architecture.  show_stack(NULL, NULL) dumps the backtrace for the
current task as does dump_stack().  On some archs, dump_stack() prints
extra information - pid, utsname and so on - in addition to the
backtrace while the two are identical on other archs.

The usages in arch-independent code of the two functions indicate
show_stack(NULL, NULL) should print out bare backtrace while
dump_stack() is used for debugging purposes when something went wrong,
so it does make sense to print additional information on the task which
triggered dump_stack().

There's no reason to require archs to implement two separate but mostly
identical functions.  It leads to unnecessary subtle information.

This patch expands the dummy fallback dump_stack() implementation in
lib/dump_stack.c such that it prints out debug information (taken from
x86) and invokes show_stack(NULL, NULL) and drops arch-specific
dump_stack() implementations in all archs except blackfin.  Blackfin's
dump_stack() does something wonky that I don't understand.

Debug information can be printed separately by calling
dump_stack_print_info() so that arch-specific dump_stack()
implementation can still emit the same debug information.  This is used
in blackfin.

This patch brings the following behavior changes.

* On some archs, an extra level in backtrace for show_stack() could be
  printed.  This is because the top frame was determined in
  dump_stack() on those archs while generic dump_stack() can't do that
  reliably.  It can be compensated by inlining dump_stack() but not
  sure whether that'd be necessary.

* Most archs didn't use to print debug info on dump_stack().  They do
  now.

An example WARN dump follows.

 WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
 Hardware name: empty
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9
  0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
  ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
  0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
 Call Trace:
  [<ffffffff81c614dc>] dump_stack+0x19/0x1b
  [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
  [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8234a071>] init_workqueues+0x35/0x505
  ...

v2: CPU number added to the generic debug info as requested by s390
    folks and dropped the s390 specific dump_stack().  This loses %ksp
    from the debug message which the maintainers think isn't important
    enough to keep the s390-specific dump_stack() implementation.

    dump_stack_print_info() is moved to kernel/printk.c from
    lib/dump_stack.c.  Because linkage is per objecct file,
    dump_stack_print_info() living in the same lib file as generic
    dump_stack() means that archs which implement custom dump_stack()
    - at this point, only blackfin - can't use dump_stack_print_info()
    as that will bring in the generic version of dump_stack() too.  v1
    The v1 patch broke build on blackfin due to this issue.  The build
    breakage was reported by Fengguang Wu.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>	[s390 bits]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
Linus Torvalds 5d434fcb25 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "Usual stuff, mostly comment fixes, typo fixes, printk fixes and small
  code cleanups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (45 commits)
  mm: Convert print_symbol to %pSR
  gfs2: Convert print_symbol to %pSR
  m32r: Convert print_symbol to %pSR
  iostats.txt: add easy-to-find description for field 6
  x86 cmpxchg.h: fix wrong comment
  treewide: Fix typo in printk and comments
  doc: devicetree: Fix various typos
  docbook: fix 8250 naming in device-drivers
  pata_pdc2027x: Fix compiler warning
  treewide: Fix typo in printks
  mei: Fix comments in drivers/misc/mei
  treewide: Fix typos in kernel messages
  pm44xx: Fix comment for "CONFIG_CPU_IDLE"
  doc: Fix typo "CONFIG_CGROUP_CGROUP_MEMCG_SWAP"
  mmzone: correct "pags" to "pages" in comment.
  kernel-parameters: remove outdated 'noresidual' parameter
  Remove spurious _H suffixes from ifdef comments
  sound: Remove stray pluses from Kconfig file
  radio-shark: Fix printk "CONFIG_LED_CLASS"
  doc: put proper reference to CONFIG_MODULE_SIG_ENFORCE
  ...
2013-04-30 09:36:50 -07:00