From 4e87580e6d144e44820a0d23e756136b6218f4f0 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Tue, 14 Mar 2017 10:15:08 +0000 Subject: [PATCH] MIPS: Add defs & probing of UFR MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add definitions and probing of the UFR bit in Config5. This bit allows user mode control of the FR bit (floating point register mode). It is present if the UFRP bit is set in the floating point implementation register. This is a capability KVM may want to expose to guest kernels, even though Linux is unlikely to ever use it due to the implications for multi-threaded programs. Signed-off-by: James Hogan Acked-by: Ralf Baechle Cc: Paul Burton Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org --- arch/mips/include/asm/cpu-features.h | 4 ++++ arch/mips/include/asm/cpu.h | 1 + arch/mips/kernel/cpu-probe.c | 2 ++ 3 files changed, 7 insertions(+) diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h index e961c8a7ea66..e12d4ec6854d 100644 --- a/arch/mips/include/asm/cpu-features.h +++ b/arch/mips/include/asm/cpu-features.h @@ -444,6 +444,10 @@ # define cpu_has_msa 0 #endif +#ifndef cpu_has_ufr +# define cpu_has_ufr (cpu_data[0].options & MIPS_CPU_UFR) +#endif + #ifndef cpu_has_fre # define cpu_has_fre (cpu_data[0].options & MIPS_CPU_FRE) #endif diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h index 9a8372484edc..98f59307e6a3 100644 --- a/arch/mips/include/asm/cpu.h +++ b/arch/mips/include/asm/cpu.h @@ -415,6 +415,7 @@ enum cpu_type_enum { #define MIPS_CPU_GUESTCTL2 MBIT_ULL(50) /* CPU has VZ GuestCtl2 register */ #define MIPS_CPU_GUESTID MBIT_ULL(51) /* CPU uses VZ ASE GuestID feature */ #define MIPS_CPU_DRG MBIT_ULL(52) /* CPU has VZ Direct Root to Guest (DRG) */ +#define MIPS_CPU_UFR MBIT_ULL(53) /* CPU supports User mode FR switching */ /* * CPU ASE encodings diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index 07718bb5fc9d..708f5913a8fe 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -289,6 +289,8 @@ static void cpu_set_fpu_opts(struct cpuinfo_mips *c) MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) { if (c->fpu_id & MIPS_FPIR_3D) c->ases |= MIPS_ASE_MIPS3D; + if (c->fpu_id & MIPS_FPIR_UFRP) + c->options |= MIPS_CPU_UFR; if (c->fpu_id & MIPS_FPIR_FREP) c->options |= MIPS_CPU_FRE; } -- 2.20.1