ARM: 6355/1: hw-breakpoint: add mechanism for hooking into prefetch a…

…borts 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 <[email protected]> Cc: S. Karthikeyan <[email protected]> Signed-off-by: Will Deacon <[email protected]> Signed-off-by: Russell King <[email protected]>
zandrey · Sep 8, 2010 · 3a4b5dc · 3a4b5dc
1 parent d56557a
commit 3a4b5dc
Show file tree

Hide file tree

Showing 2 changed files with 17 additions and 0 deletions.
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
@@ -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))))
 

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
@@ -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)
 {