Patch "MIPS: DEC: Fix an int-handler.S CPU_DADDI_WORKAROUNDS regression" has been added to the 4.9-stable tree

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

MIPS: DEC: Fix an int-handler.S CPU_DADDI_WORKAROUNDS regression

to the 4.9-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-fix-an-int-handler.s-cpu_daddi_workarounds-regression.patch
and it can be found in the queue-4.9 subdirectory.

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

From: "Maciej W. Rozycki" <[email protected]>
Date: Sun, 30 Jul 2017 21:28:15 +0100
Subject: MIPS: DEC: Fix an int-handler.S CPU_DADDI_WORKAROUNDS regression

From: Maciej W. Rozycki <[email protected]>

commit 68fe55680d0f3342969f49412fceabb90bdfadba upstream.

Fix a commit 3021773c7c3e ("MIPS: DEC: Avoid la pseudo-instruction in delay slots") regression and remove assembly errors:

arch/mips/dec/int-handler.S: Assembler messages:
arch/mips/dec/int-handler.S:162: Error: Macro used $at after ".set noat" arch/mips/dec/int-handler.S:163: Error: Macro used $at after ".set noat" arch/mips/dec/int-handler.S:229: Error: Macro used $at after ".set noat" arch/mips/dec/int-handler.S:230: Error: Macro used $at after ".set noat"

triggering with with the CPU_DADDI_WORKAROUNDS option set and the DADDIU instruction. This is because with that option in place the instruction becomes a macro, which expands to an LI/DADDU (or actually ADDIU/DADDU) sequence that uses $at as a temporary register.

With CPU_DADDI_WORKAROUNDS we only support `-msym32' compilation though, and this is already enforced in arch/mips/Makefile, so choose the 32-bit expansion variant for the supported configurations and then replace the 64-bit variant with #error just in case.

Patchwork: https://patchwork.linux-mips.org/patch/16893/

---
 arch/mips/dec/int-handler.S |   34 ++++++----------------------------
 1 file changed, 6 insertions(+), 28 deletions(-)

@@ -147,23 +147,12 @@
 		 * Find irq with highest priority
 		 */
 		# open coded PTR_LA t1, cpu_mask_nr_tbl
-#if (_MIPS_SZPTR == 32)
+#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
 		# 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
+#else
+#error GCC `-msym32' option required for 64-bit DECstation builds
 #endif
 1:		lw	t2,(t1)
 		nop

@@ -214,23 +203,12 @@
 		 * Find irq with highest priority
 		 */
 		# open coded PTR_LA t1,asic_mask_nr_tbl
-#if (_MIPS_SZPTR == 32)
+#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
 		# 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
+#else
+#error GCC `-msym32' option required for 64-bit DECstation builds
 #endif
 2:		lw	t2,(t1)
 		nop

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

queue-4.9/mips-dec-fix-an-int-handler.s-cpu_daddi_workarounds-regression.patch