ARCv3: Skip r59 register for ARC64 processors when save/restore context

The r59 register is reserved for ARC64. Illegal operand exception will be
raised if it referenced.

Author: xxkent

arch/arc/include/asm/entry-cmn.h

@@ -180,8 +180,12 @@
 	STR	r10, sp, PT_sp		; pt_regs->sp
 
 #ifdef CONFIG_ARC_HAS_ACCL_REGS
+#ifdef CONFIG_ARC_CPU_HS6X
+	STR	r58, sp, PT_r58		; r59 is reserved for ARC64
+#else
 	STR2	r58, r59, sp, PT_r58
 #endif
+#endif
 
 #ifdef CONFIG_ARC_CURR_IN_REG
 	GET_CURR_TASK_ON_CPU	gp
@@ -216,8 +220,12 @@
 	DSP_RESTORE_REGFILE_IRQ
 
 #ifdef CONFIG_ARC_HAS_ACCL_REGS
+#ifdef CONFIG_ARC_CPU_HS6X
+	LDR	r58, sp, PT_r58
+#else
 	LDR2	r58, r59, sp, PT_r58
 #endif
+#endif
 .endm
 
 /*------------------------------------------------------------------------*/

arch/arc/include/asm/ptrace.h

@@ -104,7 +104,12 @@ struct callee_regs {
 struct pt_regs {
 
 	unsigned long orig_r0;
-	unsigned long r58, r59;
+#ifdef CONFIG_ARC_HAS_ACCL_REGS
+	unsigned long r58;
+#ifndef CONFIG_ARC_CPU_HS6X
+	unsigned long r59;
+#endif
+#endif
 	ecr_reg ecr;
 	unsigned long bta;
 	unsigned long fp;

arch/arc/kernel/asm-offsets.c

@@ -74,8 +74,10 @@ int main(void)
 #endif
 #ifdef CONFIG_ARC_HAS_ACCL_REGS
 	OFFSET(PT_r58, pt_regs, r58);
+#ifndef CONFIG_ARC_CPU_HS6X
 	OFFSET(PT_r59, pt_regs, r59);
 #endif
+#endif
 #ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
 	OFFSET(PT_DSP_CTRL, pt_regs, DSP_CTRL);
 #endif

arch/arc/kernel/signal.c

@@ -72,9 +72,14 @@ static int save_arcv2_regs(struct sigcontext *mctx, struct pt_regs *regs)
 #endif
 #ifdef CONFIG_ARC_HAS_ACCL_REGS
 	v2abi.r58 = regs->r58;
+#ifndef CONFIG_ARC_CPU_HS6X
 	v2abi.r59 = regs->r59;
+#endif
 #else
-	v2abi.r58 = v2abi.r59 = 0;
+	v2abi.r58 = 0;
+#ifndef CONFIG_ARC_CPU_HS6X
+	v2abi.r59 = 0;
+#endif
 #endif
 	err = __copy_to_user(&mctx->v2abi, &v2abi, sizeof(v2abi));
 #endif
@@ -94,8 +99,10 @@ static int restore_arcv2_regs(struct sigcontext *mctx, struct pt_regs *regs)
 #endif
 #ifdef CONFIG_ARC_HAS_ACCL_REGS
 	regs->r58 = v2abi.r58;
+#ifndef CONFIG_ARC_CPU_HS6X
 	regs->r59 = v2abi.r59;
 #endif
+#endif
 #endif
 	return err;
 }