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Commit 3a4b5dca authored by Will Deacon's avatar Will Deacon Committed by Russell King
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ARM: 6355/1: hw-breakpoint: add mechanism for hooking into prefetch aborts 



On ARM processors with hardware breakpoint and watchpoint support,
triggering these events results in a debug exception. These manifest
as prefetch and data aborts respectively.

arch/arm/mm/fault.c already provides hook_fault_code for hooking
into data aborts dependent on the DFSR. This patch adds a new function,
hook_ifault_code for hooking into prefetch aborts in the same manner.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: S. Karthikeyan <informkarthik@gmail.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent d56557af

arch/arm/include/asm/system.h

+4 −0
Original line number Diff line number Diff line
@@ -85,6 +85,10 @@ void hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int, 
				       struct pt_regs *),

		     int sig, int code, const char *name);



void hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int,

				       struct pt_regs *),

		     int sig, int code, const char *name);



#define xchg(ptr,x) \

	((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))

arch/arm/mm/fault.c

+13 −0
Original line number Diff line number Diff line
@@ -581,6 +581,19 @@ static struct fsr_info ifsr_info[] = { 
	{ do_bad,		SIGBUS,  0,		"unknown 31"			   },

};



void __init

hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *),

		 int sig, int code, const char *name)

{

	if (nr < 0 || nr >= ARRAY_SIZE(ifsr_info))

		BUG();



	ifsr_info[nr].fn   = fn;

	ifsr_info[nr].sig  = sig;

	ifsr_info[nr].code = code;

	ifsr_info[nr].name = name;

}



asmlinkage void __exception

do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)

{