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  • K.Prasad's avatar
    powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors · 5aae8a53
    K.Prasad authored
    
    
    Implement perf-events based hw-breakpoint interfaces for PowerPC
    64-bit server (Book III S) processors.  This allows access to a
    given location to be used as an event that can be counted or
    profiled by the perf_events subsystem.
    
    This is done using the DABR (data breakpoint register), which can
    also be used for process debugging via ptrace.  When perf_event
    hw_breakpoint support is configured in, the perf_event subsystem
    manages the DABR and arbitrates access to it, and ptrace then
    creates a perf_event when it is requested to set a data breakpoint.
    
    [Adopted suggestions from Paul Mackerras <paulus@samba.org> to
    - emulate_step() all system-wide breakpoints and single-step only the
      per-task breakpoints
    - perform arch-specific cleanup before unregistration through
      arch_unregister_hw_breakpoint()
    ]
    
    Signed-off-by: default avatarK.Prasad <prasad@linux.vnet.ibm.com>
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    5aae8a53