Unverified Commit 8dbc1864 authored Feb 02, 2018 by James Hogan

MIPS: CPS: Fix MIPS_ISA_LEVEL_RAW fallout



Commit 17278a91 ("MIPS: CPS: Fix r1 .set mt assembler warning")
added .set MIPS_ISA_LEVEL_RAW to silence warnings about .set mt on r1,
however this can result in a MOVE being encoded as a 64-bit DADDU
instruction on certain version of binutils (e.g. 2.22), and reserved
instruction exceptions at runtime on 32-bit hardware.

Reduce the sizes of the push/pop sections to include only instructions
that are part of the MT ASE or which won't convert to 64-bit
instructions after .set mips64r2/mips64r6.

Reported-by: Greg Ungerer <gerg@linux-m68k.org>
Fixes: 17278a91 ("MIPS: CPS: Fix r1 .set mt assembler warning")
Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.15
Tested-by: Greg Ungerer <gerg@linux-m68k.org>
Patchwork: https://patchwork.linux-mips.org/patch/18578/

parent d8a5b805

arch/mips/kernel/cps-vec.S

+12 −5

Original line number	Diff line number	Diff line
		@@ -388,15 +388,16 @@ LEAF(mips_cps_boot_vpes)

		#elif defined(CONFIG_MIPS_MT)

		.set push
		.set MIPS_ISA_LEVEL_RAW
		.set mt

		/* If the core doesn't support MT then return */
		has_mt t0, 5f

		/* Enter VPE configuration state */
		.set push
		.set MIPS_ISA_LEVEL_RAW
		.set mt
		dvpe
		.set pop

		PTR_LA t1, 1f
		jr.hb t1
		nop
		@@ -422,6 +423,10 @@ LEAF(mips_cps_boot_vpes)
		mtc0 t0, CP0_VPECONTROL
		ehb

		.set push
		.set MIPS_ISA_LEVEL_RAW
		.set mt

		/* Skip the VPE if its TC is not halted */
		mftc0 t0, CP0_TCHALT
		beqz t0, 2f
		@@ -495,6 +500,8 @@ LEAF(mips_cps_boot_vpes)
		ehb
		evpe

		.set pop

		/* Check whether this VPE is meant to be running */
		li t0, 1
		sll t0, t0, a1
		@@ -509,7 +516,7 @@ LEAF(mips_cps_boot_vpes)
		1: jr.hb t0
		nop

		2: .set pop
		2:

		#endif /* CONFIG_MIPS_MT_SMP */