Patch "MIPS: DEC: Avoid la pseudo-instruction in delay slots" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

MIPS: DEC: Avoid la pseudo-instruction in delay slots

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mips-dec-avoid-la-pseudo-instruction-in-delay-slots.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Ralf Baechle <[email protected]>
Date: Tue, 20 Sep 2016 14:33:01 +0200
Subject: MIPS: DEC: Avoid la pseudo-instruction in delay slots

From: Ralf Baechle <[email protected]>

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.

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

@@ -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

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/mips-ip27-disable-qlge-driver-in-defconfig.patch queue-4.4/mips-netlogic-fix-cp0_ebase-redefinition-warnings.patch queue-4.4/mips-update-ip27_defconfig-for-scsi_dh-change.patch queue-4.4/mips-dec-avoid-la-pseudo-instruction-in-delay-slots.patch queue-4.4/mips-ralink-cosmetic-change-to-prom_init.patch queue-4.4/mips-ip22-fix-ip28-build-for-modern-gcc.patch queue-4.4/mips-update-lemote2f_defconfig-for-cpu_freq_stat-change.patch queue-4.4/crypto-improve-gcc-optimization-flags-for-serpent-and-wp512.patch queue-4.4/mips-ralink-remove-unused-rt-_wdt_reset-functions.patch queue-4.4/mips-ralink-remove-unused-timer-functions.patch queue-4.4/mips-update-defconfigs-for-nf_ct_proto_dccp-udplite-change.patch