1. 19 Jun, 2015 1 commit
    • Vladimir Murzin's avatar
      arm64: use private ratelimit state along with show_unhandled_signals · 86dca36e
      Vladimir Murzin authored
      printk_ratelimit() shares the ratelimiting state with other callers what
      may lead to scenarios where at the time we want to print out debug
      information we already limited, so nothing appears in the dmesg - this
      makes exception-trace quite poor helper in debugging.
      
      Additionally, we have imbalance with some messages limited with global
      ratelimit state and other messages limited with their private state
      defined via pr_*_ratelimited().
      
      To address this inconsistency show_unhandled_signals_ratelimited()
      macro is introduced and caller sites are converted to use it.
      Signed-off-by: default avatarVladimir Murzin <vladimir.murzin@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      86dca36e
  2. 15 Jan, 2015 1 commit
  3. 20 Nov, 2014 1 commit
  4. 08 Sep, 2014 1 commit
  5. 23 Jul, 2014 1 commit
    • Jungseok Lee's avatar
      arm64: mm: Implement 4 levels of translation tables · c79b954b
      Jungseok Lee authored
      This patch implements 4 levels of translation tables since 3 levels
      of page tables with 4KB pages cannot support 40-bit physical address
      space described in [1] due to the following issue.
      
      It is a restriction that kernel logical memory map with 4KB + 3 levels
      (0xffffffc000000000-0xffffffffffffffff) cannot cover RAM region from
      544GB to 1024GB in [1]. Specifically, ARM64 kernel fails to create
      mapping for this region in map_mem function since __phys_to_virt for
      this region reaches to address overflow.
      
      If SoC design follows the document, [1], over 32GB RAM would be placed
      from 544GB. Even 64GB system is supposed to use the region from 544GB
      to 576GB for only 32GB RAM. Naturally, it would reach to enable 4 levels
      of page tables to avoid hacking __virt_to_phys and __phys_to_virt.
      
      However, it is recommended 4 levels of page table should be only enabled
      if memory map is too sparse or there is about 512GB RAM.
      
      References
      ----------
      [1]: Principles of ARM Memory Maps, White Paper, Issue C
      Signed-off-by: default avatarJungseok Lee <jays.lee@samsung.com>
      Reviewed-by: default avatarSungjinn Chung <sungjinn.chung@samsung.com>
      Acked-by: default avatarKukjin Kim <kgene.kim@samsung.com>
      Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
      Reviewed-by: default avatarSteve Capper <steve.capper@linaro.org>
      [catalin.marinas@arm.com: MEMBLOCK_INITIAL_LIMIT removed, same as PUD_SIZE]
      [catalin.marinas@arm.com: early_ioremap_init() updated for 4 levels]
      [catalin.marinas@arm.com: 48-bit VA depends on BROKEN until KVM is fixed]
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Tested-by: default avatarJungseok Lee <jungseoklee85@gmail.com>
      c79b954b
  6. 17 Jul, 2014 1 commit
  7. 09 May, 2014 1 commit
  8. 12 Jun, 2013 1 commit
  9. 31 May, 2013 1 commit
  10. 24 May, 2013 1 commit
  11. 30 Apr, 2013 1 commit
    • Tejun Heo's avatar
      dump_stack: consolidate dump_stack() implementations and unify their behaviors · 196779b9
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
      Acked-by: default avatarVineet Gupta <vgupta@synopsys.com>
      Acked-by: default avatarJesper Nilsson <jesper.nilsson@axis.com>
      Acked-by: default avatarVineet 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: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      196779b9
  12. 20 Jan, 2013 1 commit
  13. 17 Sep, 2012 1 commit