[PATCH 3.18 137/145] MIPS: DEC: Avoid la pseudo-instruction in delay slots

Greg Kroah-Hartman
2017-04-16T11:01:51Z

From: Ralf Baechle <ralf@linux-mips.org>

commit 3021773c7c3e75e20b693931a19362681e744ea9 upstream.

When expanding the la or dla pseudo-instruction in a delay slot the GNU
assembler will complain should the pseudo-instruction expand to multiple
actual instructions, since only the first of them will be in the delay
slot leading to the pseudo-instruction being only partially executed if
the branch is taken. Use of PTR_LA in the dec int-handler.S leads to
such warnings:

arch/mips/dec/int-handler.S: Assembler messages:
arch/mips/dec/int-handler.S:149: Warning: macro instruction expanded into multiple instructions in a branch delay slot
arch/mips/dec/int-handler.S:198: Warning: macro instruction expanded into multiple instructions in a branch delay slot

Avoid this by open coding the PTR_LA macros.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/mips/dec/int-handler.S | 40 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 38 insertions(+), 2 deletions(-)

--- a/arch/mips/dec/int-handler.S
+++ b/arch/mips/dec/int-handler.S
@@ -146,7 +146,25 @@
/*
* Find irq with highest priority
*/
- PTR_LA t1,cpu_mask_nr_tbl
+ # open coded PTR_LA t1, cpu_mask_nr_tbl
+#if (_MIPS_SZPTR == 32)
+ # open coded la t1, cpu_mask_nr_tbl
+ lui t1, %hi(cpu_mask_nr_tbl)
+ addiu t1, %lo(cpu_mask_nr_tbl)
+
+#endif
+#if (_MIPS_SZPTR == 64)
+ # open coded dla t1, cpu_mask_nr_tbl
+ .set push
+ .set noat
+ lui t1, %highest(cpu_mask_nr_tbl)
+ lui AT, %hi(cpu_mask_nr_tbl)
+ daddiu t1, t1, %higher(cpu_mask_nr_tbl)
+ daddiu AT, AT, %lo(cpu_mask_nr_tbl)
+ dsll t1, 32
+ daddu t1, t1, AT
+ .set pop
+#endif
1: lw t2,(t1)
nop
and t2,t0
@@ -195,7 +213,25 @@
/*
* Find irq with highest priority
*/
- PTR_LA t1,asic_mask_nr_tbl
+ # open coded PTR_LA t1,asic_mask_nr_tbl
+#if (_MIPS_SZPTR == 32)
+ # open coded la t1, asic_mask_nr_tbl
+ lui t1, %hi(asic_mask_nr_tbl)
+ addiu t1, %lo(asic_mask_nr_tbl)
+
+#endif
+#if (_MIPS_SZPTR == 64)
+ # open coded dla t1, asic_mask_nr_tbl
+ .set push
+ .set noat
+ lui t1, %highest(asic_mask_nr_tbl)
+ lui AT, %hi(asic_mask_nr_tbl)
+ daddiu t1, t1, %higher(asic_mask_nr_tbl)
+ daddiu AT, AT, %lo(asic_mask_nr_tbl)
+ dsll t1, 32
+ daddu t1, t1, AT
+ .set pop
+#endif
2: lw t2,(t1)
nop
and t2,t0