1. 09 Sep, 2016 23 commits
  2. 08 Sep, 2016 1 commit
    • Robin Murphy's avatar
      arm64/io: Allow I/O writes to use {W,X}ZR · ee5e41b5
      Robin Murphy authored
      When zeroing an I/O location, the current accessors are forced to
      allocate a temporary register to store the zero for the write. By
      tweaking the assembly constraints, we can allow the compiler to use
      the zero register directly in such cases, and save some juggling.
      Compiling a representative kernel configuration with GCC 6 shows
      that 2.3KB worth of code can be wasted just on that!
      
        text     data    bss      dec      hex     filename
       13316776 3248256 18176769 34741801 2121e29 vmlinux.o.new
       13319140 3248256 18176769 34744165 2122765 vmlinux.o.old
      Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
      Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      ee5e41b5
  3. 07 Sep, 2016 2 commits
  4. 06 Sep, 2016 2 commits
  5. 05 Sep, 2016 3 commits
    • Pratyush Anand's avatar
      arm64: ftrace: add save_stack_trace_regs() · 98ab10e9
      Pratyush Anand authored
      Currently, enabling stacktrace of a kprobe events generates warning:
      
        echo stacktrace > /sys/kernel/debug/tracing/trace_options
        echo "p xhci_irq" > /sys/kernel/debug/tracing/kprobe_events
        echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable
      
      save_stack_trace_regs() not implemented yet.
      ------------[ cut here ]------------
      WARNING: CPU: 1 PID: 0 at ../kernel/stacktrace.c:74 save_stack_trace_regs+0x3c/0x48
      Modules linked in:
      
      CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.8.0-rc4-dirty #5128
      Hardware name: ARM Juno development board (r1) (DT)
      task: ffff800975dd1900 task.stack: ffff800975ddc000
      PC is at save_stack_trace_regs+0x3c/0x48
      LR is at save_stack_trace_regs+0x3c/0x48
      pc : [<ffff000008126c64>] lr : [<ffff000008126c64>] pstate: 600003c5
      sp : ffff80097ef52c00
      
      Call trace:
         save_stack_trace_regs+0x3c/0x48
         __ftrace_trace_stack+0x168/0x208
         trace_buffer_unlock_commit_regs+0x5c/0x7c
         kprobe_trace_func+0x308/0x3d8
         kprobe_dispatcher+0x58/0x60
         kprobe_breakpoint_handler+0xbc/0x18c
         brk_handler+0x50/0x90
         do_debug_exception+0x50/0xbc
      
      This patch implements save_stack_trace_regs(), so that stacktrace of a
      kprobe events can be obtained.
      
      After this patch, there is no warning and we can see the stacktrace for
      kprobe events in trace buffer.
      
      more /sys/kernel/debug/tracing/trace
                <idle>-0     [004] d.h.  1356.000496: p_xhci_irq_0:(xhci_irq+0x0/0x9ac)
                <idle>-0     [004] d.h.  1356.000497: <stack trace>
        => xhci_irq
        => __handle_irq_event_percpu
        => handle_irq_event_percpu
        => handle_irq_event
        => handle_fasteoi_irq
        => generic_handle_irq
        => __handle_domain_irq
        => gic_handle_irq
        => el1_irq
        => arch_cpu_idle
        => default_idle_call
        => cpu_startup_entry
        => secondary_start_kernel
        =>
      Tested-by: default avatarDavid A. Long <dave.long@linaro.org>
      Reviewed-by: default avatarJames Morse <james.morse@arm.com>
      Signed-off-by: default avatarPratyush Anand <panand@redhat.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      98ab10e9
    • Ard Biesheuvel's avatar
      arm64: kernel: re-export _cpu_resume() from sleep.S · dc002475
      Ard Biesheuvel authored
      Commit b5fe2429 ("arm64: kernel: fix style issues in sleep.S")
      changed the linkage of _cpu_resume() to local, even though the symbol
      is also referenced from hibernate.c. So revert this change.
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      dc002475
    • James Morse's avatar
      arm64: Drop generic xlate_dev_mem_{k,}ptr() · f928c16d
      James Morse authored
      The code that provides /dev/mem uses xlate_dev_mem_{k,}ptr() to
      avoid making a cachable mapping of a non-cachable area on ia64.
      On arm64 we do this via phys_mem_access_prot() instead, but provide
      dummy versions of xlate_dev_mem_{k,}ptr().
      
      These are the same as those in asm-generic/io.h, which we include from
      asm/io.h
      Signed-off-by: default avatarJames Morse <james.morse@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      f928c16d
  6. 02 Sep, 2016 8 commits
  7. 01 Sep, 2016 1 commit