[PATCH 3/7] microblaze: exception: fix delay slot exception handling

Ovidiu Panait ovidiu.panait at windriver.com
Sun Feb 13 09:09:21 CET 2022


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 at windriver.com>
---

 arch/microblaze/cpu/exception.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/microblaze/cpu/exception.c b/arch/microblaze/cpu/exception.c
index 5601dde5b4..64d5fe4a80 100644
--- 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;
-- 
2.25.1



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