Commit ee54d379 authored by Tiezhu Yang's avatar Tiezhu Yang Committed by Thomas Bogendoerfer
Browse files

MIPS: Make check condition for SDBBP consistent with EJTAG spec 

According to MIPS EJTAG Specification [1], a Debug Breakpoint
exception occurs when an SDBBP instruction is executed, the
CP0_DEBUG bit DBp indicates that a Debug Breakpoint exception
occurred.

When I read the original code, it looks a little confusing
at first glance, just check bit DBp for SDBBP to make the
code more readable, it will be much easier to understand.

[1] http://www.t-es-t.hu/download/mips/md00047f.pdf



Signed-off-by: default avatarTiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: default avatarThomas Bogendoerfer <tsbogend@alpha.franken.de>
parent e66ef72d

arch/mips/include/asm/mipsregs.h

+4 −0
Original line number Diff line number Diff line
@@ -1085,6 +1085,10 @@ 
#define CVMVMCONF_RMMUSIZEM1_S	0

#define CVMVMCONF_RMMUSIZEM1	(_U64CAST_(0xff) << CVMVMCONF_RMMUSIZEM1_S)



/* Debug register field definitions */

#define MIPS_DEBUG_DBP_SHIFT	1

#define MIPS_DEBUG_DBP		(_ULCAST_(1) << MIPS_DEBUG_DBP_SHIFT)



/*

 * Coprocessor 1 (FPU) register names

 */

arch/mips/kernel/genex.S

+2 −2
Original line number Diff line number Diff line
@@ -349,8 +349,8 @@ NESTED(ejtag_debug_handler, PT_SIZE, sp) 
	MTC0	k0, CP0_DESAVE

	mfc0	k0, CP0_DEBUG



	sll	k0, k0, 30	# Check for SDBBP.

	bgez	k0, ejtag_return

	andi	k0, k0, MIPS_DEBUG_DBP	# Check for SDBBP.

	beqz	k0, ejtag_return



#ifdef CONFIG_SMP

1:	PTR_LA	k0, ejtag_debug_buffer_spinlock