[PATCH 6.6 073/396] powerpc/fsl: Fix mfpmr build errors with newer binutils

Greg Kroah-Hartman
2024-04-01T16:38:37Z

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit 5f491356b7149564ab22323ccce79c8d595bfd0c ]

Binutils 2.38 complains about the use of mfpmr when building
ppc6xx_defconfig:

CC arch/powerpc/kernel/pmc.o
{standard input}: Assembler messages:
{standard input}:45: Error: unrecognized opcode: `mfpmr'
{standard input}:56: Error: unrecognized opcode: `mtpmr'

This is because by default the kernel is built with -mcpu=powerpc, and
the mt/mfpmr instructions are not defined.

It can be avoided by enabling CONFIG_E300C3_CPU, but just adding that to
the defconfig will leave open the possibility of randconfig failures.

So add machine directives around the mt/mfpmr instructions to tell
binutils how to assemble them.

Cc: stable@vger.kernel.org
Reported-by: Jan-Benedict Glaw <jbglaw@lug-owl.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240229122521.762431-3-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/include/asm/reg_fsl_emb.h | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/reg_fsl_emb.h b/arch/powerpc/include/asm/reg_fsl_emb.h
index a21f529c43d96..8359c06d92d9f 100644
--- a/arch/powerpc/include/asm/reg_fsl_emb.h
+++ b/arch/powerpc/include/asm/reg_fsl_emb.h
@@ -12,9 +12,16 @@
#ifndef __ASSEMBLY__
/* Performance Monitor Registers */
#define mfpmr(rn) ({unsigned int rval; \
- asm volatile("mfpmr %0," __stringify(rn) \
+ asm volatile(".machine push; " \
+ ".machine e300; " \
+ "mfpmr %0," __stringify(rn) ";" \
+ ".machine pop; " \
: "=r" (rval)); rval;})
-#define mtpmr(rn, v) asm volatile("mtpmr " __stringify(rn) ",%0" : : "r" (v))
+#define mtpmr(rn, v) asm volatile(".machine push; " \
+ ".machine e300; " \
+ "mtpmr " __stringify(rn) ",%0; " \
+ ".machine pop; " \
+ : : "r" (v))
#endif /* __ASSEMBLY__ */

/* Freescale Book E Performance Monitor APU Registers */
--
2.43.0