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Commit 162b0809 authored by Pratik Patel's avatar Pratik Patel Committed by Jeevan Shriram
Browse files

ARM: hw_breakpoint: don't clear bkpts during halting mode debug 



Skip clearing breakpoints and enabling monitor mode when halting
debug mode is enabled. This avoids wiping out user configured
breakpoints as part of halting mode debug.

Change-Id: I0dcd1b7dc048f3d795b0c7c31ba6b90d7b6e9eeb
Signed-off-by: default avatarPratik Patel <pratikp@codeaurora.org>
Signed-off-by: default avatarJeevan Shriram <jshriram@codeaurora.org>
parent 6a238dc8

arch/arm/kernel/hw_breakpoint.c

+23 −0
Original line number Diff line number Diff line
@@ -226,6 +226,18 @@ static int get_num_brps(void) 
	return core_has_mismatch_brps() ? brps - 1 : brps;

}



/* Determine if halting mode is enabled */

static int halting_mode_enabled(void)

{

	u32 dscr;



	ARM_DBG_READ(c0, c1, 0, dscr);

	WARN_ONCE(dscr & ARM_DSCR_HDBGEN,

	  "halting debug mode enabled. Unable to access hardware resources.\n");



	return !!(dscr & ARM_DSCR_HDBGEN);

}



/*

 * In order to access the breakpoint/watchpoint control registers,

 * we must be running in debug monitor mode. Unfortunately, we can
@@ -930,6 +942,17 @@ static void reset_ctrl_regs(unsigned int cpu) 
	int i, raw_num_brps, err = 0;

	u32 val;



	/*

	 * Bail out without clearing the breakpoint registers if halting

	 * debug mode or monitor debug mode is enabled. Checking for monitor

	 * debug mode here ensures we don't clear the breakpoint registers

	 * across power collapse if save and restore code has already

	 * preserved the debug register values or they weren't lost and

	 * monitor mode was already enabled earlier.

	 */

	if (halting_mode_enabled() || monitor_mode_enabled())

		return;



	/*

	 * v7 debug contains save and restore registers so that debug state

	 * can be maintained across low-power modes without leaving the debug