From ba12400ed8b90bbdc1579efceba8cb67361ace60 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Fri, 4 Mar 2022 20:16:23 +0000 Subject: [PATCH] DEC: Limit PMAX memory probing to R3k systems commit 244eae91a94c6dab82b3232967d10eeb9dfa21c6 upstream. Recent tightening of the opcode table in binutils so as to consistently disallow the assembly or disassembly of CP0 instructions not supported by the processor architecture chosen has caused a regression like below: arch/mips/dec/prom/locore.S: Assembler messages: arch/mips/dec/prom/locore.S:29: Error: opcode not supported on this processor: r4600 (mips3) `rfe' in a piece of code used to probe for memory with PMAX DECstation models, which have non-REX firmware. Those computers always have an R2000 CPU and consequently the exception handler used in memory probing uses the RFE instruction, which those processors use. While adding 64-bit support this code was correctly excluded for 64-bit configurations, however it should have also been excluded for irrelevant 32-bit configurations. Do this now then, and only enable PMAX memory probing for R3k systems. Reported-by: Jan-Benedict Glaw Reported-by: Sudip Mukherjee Signed-off-by: Maciej W. Rozycki Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org # v2.6.12+ Signed-off-by: Thomas Bogendoerfer Signed-off-by: Greg Kroah-Hartman --- arch/mips/dec/prom/Makefile | 2 +- arch/mips/include/asm/dec/prom.h | 15 +++++---------- 2 files changed, 6 insertions(+), 11 deletions(-) diff --git a/arch/mips/dec/prom/Makefile b/arch/mips/dec/prom/Makefile index ae73e42ac20b..4c369359cdab 100644 --- a/arch/mips/dec/prom/Makefile +++ b/arch/mips/dec/prom/Makefile @@ -5,4 +5,4 @@ lib-y += init.o memory.o cmdline.o identify.o console.o -lib-$(CONFIG_32BIT) += locore.o +lib-$(CONFIG_CPU_R3000) += locore.o diff --git a/arch/mips/include/asm/dec/prom.h b/arch/mips/include/asm/dec/prom.h index b59a2103b61a..09538ff5e924 100644 --- a/arch/mips/include/asm/dec/prom.h +++ b/arch/mips/include/asm/dec/prom.h @@ -47,16 +47,11 @@ */ #define REX_PROM_MAGIC 0x30464354 -#ifdef CONFIG_64BIT - -#define prom_is_rex(magic) 1 /* KN04 and KN05 are REX PROMs. */ - -#else /* !CONFIG_64BIT */ - -#define prom_is_rex(magic) ((magic) == REX_PROM_MAGIC) - -#endif /* !CONFIG_64BIT */ - +/* KN04 and KN05 are REX PROMs, so only do the check for R3k systems. */ +static inline bool prom_is_rex(u32 magic) +{ + return !IS_ENABLED(CONFIG_CPU_R3000) || magic == REX_PROM_MAGIC; +} /* * 3MIN/MAXINE PROM entry points for DS5000/1xx's, DS5000/xx's and