microblaze: exception: fix delay slot exception handling

The switch statement in _hw_exception_handler() only covers the
rightmost 5 bits that encode the exception cause:
switch (state & 0x1f)
{
...
}

For this reason, the "0x1000" case will never be reached, because the 13th
bit was zeroed out. To fix this, move delay slot exception handling before
the switch statement (delay slot (DS) bit in Exception Status Register is
independent of the exception cause (EC)).

Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Link: https://lore.kernel.org/r/20220213080925.1548411-3-ovidiu.panait@windriver.com
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/arch/microblaze/cpu/exception.c b/arch/microblaze/cpu/exception.c
index 5601dde..64d5fe4 100644 (file)
--- a/arch/microblaze/cpu/exception.c
+++ b/arch/microblaze/cpu/exception.c
@@ -21,6 +21,11 @@ void _hw_exception_handler (void)
        printf("Hardware exception at 0x%x address\n", address);
        R17(address);
        printf("Return address from exception 0x%x\n", address);
+
+       if (CONFIG_IS_ENABLED(XILINX_MICROBLAZE0_DELAY_SLOT_EXCEP) &&
+           (state & 0x1000))
+               puts("Exception in delay slot\n");
+
        switch (state & 0x1f) { /* mask on exception cause */
        case 0x1:
                puts("Unaligned data access exception\n");
@@ -40,11 +45,6 @@ void _hw_exception_handler (void)
        case 0x7:
                puts("Priviledged or stack protection violation exception\n");
                break;
-#if CONFIG_IS_ENABLED(XILINX_MICROBLAZE0_DELAY_SLOT_EXCEP)
-       case 0x1000:
-               puts("Exception in delay slot\n");
-               break;
-#endif
        default:
                puts("Undefined cause\n");
                break;