microblaze: Change register usage for ESR and EAR

This change synchronize register usage in code.
ESR = R4
EAR = R3

Signed-off-by: Michal Simek <monstr@monstr.eu>

diff --git a/arch/microblaze/kernel/hw_exception_handler.S b/arch/microblaze/kernel/hw_exception_handler.S
index ad6dbf0..a652add 100644 (file)
--- a/arch/microblaze/kernel/hw_exception_handler.S
+++ b/arch/microblaze/kernel/hw_exception_handler.S
@@ -313,13 +313,13 @@ _hw_exception_handler:
        mfs     r5, rmsr;
        nop
        swi     r5, r1, 0;
-       mfs     r3, resr
+       mfs     r4, resr
        nop
-       mfs     r4, rear;
+       mfs     r3, rear;
        nop
 
 #ifndef CONFIG_MMU
-       andi    r5, r3, 0x1000;         /* Check ESR[DS] */
+       andi    r5, r4, 0x1000;         /* Check ESR[DS] */
        beqi    r5, not_in_delay_slot;  /* Branch if ESR[DS] not set */
        mfs     r17, rbtr;      /* ESR[DS] set - return address in BTR */
        nop
@@ -327,7 +327,7 @@ not_in_delay_slot:
        swi     r17, r1, PT_R17
 #endif
 
-       andi    r5, r3, 0x1F;           /* Extract ESR[EXC] */
+       andi    r5, r4, 0x1F;           /* Extract ESR[EXC] */
 
 #ifdef CONFIG_MMU
        /* Calculate exception vector offset = r5 << 2 */
@@ -378,7 +378,7 @@ handle_other_ex: /* Handle Other exceptions here */
        swi     r18, r1, PT_R18
 
        or      r5, r1, r0
-       andi    r6, r3, 0x1F; /* Load ESR[EC] */
+       andi    r6, r4, 0x1F; /* Load ESR[EC] */
        lwi     r7, r0, PER_CPU(KM) /* MS: saving current kernel mode to regs */
        swi     r7, r1, PT_MODE
        mfs     r7, rfsr
@@ -428,11 +428,11 @@ handle_other_ex: /* Handle Other exceptions here */
  */
 handle_unaligned_ex:
        /* Working registers already saved: R3, R4, R5, R6
-        *  R3 = ESR
-        *  R4 = EAR
+        *  R4 = ESR
+        *  R3 = EAR
         */
 #ifdef CONFIG_MMU
-       andi    r6, r3, 0x1000                  /* Check ESR[DS] */
+       andi    r6, r4, 0x1000                  /* Check ESR[DS] */
        beqi    r6, _no_delayslot               /* Branch if ESR[DS] not set */
        mfs     r17, rbtr;      /* ESR[DS] set - return address in BTR */
        nop
@@ -441,7 +441,7 @@ _no_delayslot:
        RESTORE_STATE;
        bri     unaligned_data_trap
 #endif
-       andi    r6, r3, 0x3E0; /* Mask and extract the register operand */
+       andi    r6, r4, 0x3E0; /* Mask and extract the register operand */
        srl     r6, r6; /* r6 >> 5 */
        srl     r6, r6;
        srl     r6, r6;
@@ -450,33 +450,33 @@ _no_delayslot:
        /* Store the register operand in a temporary location */
        sbi     r6, r0, TOPHYS(ex_reg_op);
 
-       andi    r6, r3, 0x400; /* Extract ESR[S] */
+       andi    r6, r4, 0x400; /* Extract ESR[S] */
        bnei    r6, ex_sw;
 ex_lw:
-       andi    r6, r3, 0x800; /* Extract ESR[W] */
+       andi    r6, r4, 0x800; /* Extract ESR[W] */
        beqi    r6, ex_lhw;
-       lbui    r5, r4, 0; /* Exception address in r4 */
+       lbui    r5, r3, 0; /* Exception address in r3 */
        /* Load a word, byte-by-byte from destination address
                and save it in tmp space */
        sbi     r5, r0, TOPHYS(ex_tmp_data_loc_0);
-       lbui    r5, r4, 1;
+       lbui    r5, r3, 1;
        sbi     r5, r0, TOPHYS(ex_tmp_data_loc_1);
-       lbui    r5, r4, 2;
+       lbui    r5, r3, 2;
        sbi     r5, r0, TOPHYS(ex_tmp_data_loc_2);
-       lbui    r5, r4, 3;
+       lbui    r5, r3, 3;
        sbi     r5, r0, TOPHYS(ex_tmp_data_loc_3);
-       /* Get the destination register value into r3 */
-       lwi     r3, r0, TOPHYS(ex_tmp_data_loc_0);
+       /* Get the destination register value into r4 */
+       lwi     r4, r0, TOPHYS(ex_tmp_data_loc_0);
        bri     ex_lw_tail;
 ex_lhw:
-       lbui    r5, r4, 0; /* Exception address in r4 */
+       lbui    r5, r3, 0; /* Exception address in r3 */
        /* Load a half-word, byte-by-byte from destination
                address and save it in tmp space */
        sbi     r5, r0, TOPHYS(ex_tmp_data_loc_0);
-       lbui    r5, r4, 1;
+       lbui    r5, r3, 1;
        sbi     r5, r0, TOPHYS(ex_tmp_data_loc_1);
-       /* Get the destination register value into r3 */
-       lhui    r3, r0, TOPHYS(ex_tmp_data_loc_0);
+       /* Get the destination register value into r4 */
+       lhui    r4, r0, TOPHYS(ex_tmp_data_loc_0);
 ex_lw_tail:
        /* Get the destination register number into r5 */
        lbui    r5, r0, TOPHYS(ex_reg_op);
@@ -504,25 +504,25 @@ ex_sw_tail:
        andi    r6, r6, 0x800; /* Extract ESR[W] */
        beqi    r6, ex_shw;
        /* Get the word - delay slot */
-       swi     r3, r0, TOPHYS(ex_tmp_data_loc_0);
+       swi     r4, r0, TOPHYS(ex_tmp_data_loc_0);
        /* Store the word, byte-by-byte into destination address */
-       lbui    r3, r0, TOPHYS(ex_tmp_data_loc_0);
-       sbi     r3, r4, 0;
-       lbui    r3, r0, TOPHYS(ex_tmp_data_loc_1);
-       sbi     r3, r4, 1;
-       lbui    r3, r0, TOPHYS(ex_tmp_data_loc_2);
-       sbi     r3, r4, 2;
-       lbui    r3, r0, TOPHYS(ex_tmp_data_loc_3);
-       sbi     r3, r4, 3;
+       lbui    r4, r0, TOPHYS(ex_tmp_data_loc_0);
+       sbi     r4, r3, 0;
+       lbui    r4, r0, TOPHYS(ex_tmp_data_loc_1);
+       sbi     r4, r3, 1;
+       lbui    r4, r0, TOPHYS(ex_tmp_data_loc_2);
+       sbi     r4, r3, 2;
+       lbui    r4, r0, TOPHYS(ex_tmp_data_loc_3);
+       sbi     r4, r3, 3;
        bri     ex_handler_done;
 
 ex_shw:
        /* Store the lower half-word, byte-by-byte into destination address */
-       swi     r3, r0, TOPHYS(ex_tmp_data_loc_0);
-       lbui    r3, r0, TOPHYS(ex_tmp_data_loc_2);
-       sbi     r3, r4, 0;
-       lbui    r3, r0, TOPHYS(ex_tmp_data_loc_3);
-       sbi     r3, r4, 1;
+       swi     r4, r0, TOPHYS(ex_tmp_data_loc_0);
+       lbui    r4, r0, TOPHYS(ex_tmp_data_loc_2);
+       sbi     r4, r3, 0;
+       lbui    r4, r0, TOPHYS(ex_tmp_data_loc_3);
+       sbi     r4, r3, 1;
 ex_sw_end: /* Exception handling of store word, ends. */
 
 ex_handler_done: