powerpc/64e: Get dear offset with _DEAR macro

Use _DEAR to get the offset of dear register in pr_regs for 64e cpus.

Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210807010239.416055-5-sxwjean@me.com

arch/powerpc/kernel/asm-offsets.c

@@ -286,23 +286,16 @@ int main(void)
 	STACK_PT_REGS_OFFSET(_CCR, ccr);
 	STACK_PT_REGS_OFFSET(_XER, xer);
 	STACK_PT_REGS_OFFSET(_DAR, dar);
+	STACK_PT_REGS_OFFSET(_DEAR, dear);
 	STACK_PT_REGS_OFFSET(_DSISR, dsisr);
 	STACK_PT_REGS_OFFSET(_ESR, esr);
 	STACK_PT_REGS_OFFSET(ORIG_GPR3, orig_gpr3);
 	STACK_PT_REGS_OFFSET(RESULT, result);
 	STACK_PT_REGS_OFFSET(_TRAP, trap);
-#ifndef CONFIG_PPC64
-	/*
-	 * The PowerPC 400-class & Book-E processors have neither the DAR
-	 * nor the DSISR SPRs. Hence, we overload them to hold the similar
-	 * DEAR and ESR SPRs for such processors.  For critical interrupts
-	 * we use them to hold SRR0 and SRR1.
-	 */
-	STACK_PT_REGS_OFFSET(_DEAR, dar);
-#else /* CONFIG_PPC64 */
+#ifdef CONFIG_PPC64
 	STACK_PT_REGS_OFFSET(SOFTE, softe);
 	STACK_PT_REGS_OFFSET(_PPR, ppr);
-#endif /* CONFIG_PPC64 */
+#endif
 
 #ifdef CONFIG_PPC_PKEY
 	STACK_PT_REGS_OFFSET(STACK_REGS_AMR, amr);

arch/powerpc/kernel/exceptions-64e.S

@@ -545,7 +545,7 @@ __end_interrupts:
 				PROLOG_ADDITION_2REGS)
 	mfspr	r14,SPRN_DEAR
 	mfspr	r15,SPRN_ESR
-	std	r14,_DAR(r1)
+	std	r14,_DEAR(r1)
 	std	r15,_ESR(r1)
 	ld	r14,PACA_EXGEN+EX_R14(r13)
 	ld	r15,PACA_EXGEN+EX_R15(r13)
@@ -558,7 +558,7 @@ __end_interrupts:
 				PROLOG_ADDITION_2REGS)
 	li	r15,0
 	mr	r14,r10
-	std	r14,_DAR(r1)
+	std	r14,_DEAR(r1)
 	std	r15,_ESR(r1)
 	ld	r14,PACA_EXGEN+EX_R14(r13)
 	ld	r15,PACA_EXGEN+EX_R15(r13)
@@ -575,7 +575,7 @@ __end_interrupts:
 				PROLOG_ADDITION_2REGS)
 	mfspr	r14,SPRN_DEAR
 	mfspr	r15,SPRN_ESR
-	std	r14,_DAR(r1)
+	std	r14,_DEAR(r1)
 	std	r15,_ESR(r1)
 	ld	r14,PACA_EXGEN+EX_R14(r13)
 	ld	r15,PACA_EXGEN+EX_R15(r13)
@@ -1057,7 +1057,7 @@ bad_stack_book3e:
 	std	r11,_CCR(r1)
 	mfspr	r10,SPRN_DEAR
 	mfspr	r11,SPRN_ESR
-	std	r10,_DAR(r1)
+	std	r10,_DEAR(r1)
 	std	r11,_ESR(r1)
 	std	r0,GPR0(r1);		/* save r0 in stackframe */	    \
 	std	r2,GPR2(r1);		/* save r2 in stackframe */	    \