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authorJiaxun Yang <jiaxun.yang@flygoat.com>2020-01-13 13:16:11 +0300
committerPaul Burton <paulburton@kernel.org>2020-01-23 02:56:08 +0300
commitece276de2a1f90b6a7836d388c372b9025345469 (patch)
tree7a1a50ccc9502f153efd87015a51a2c8fdb9b961 /arch/mips/include
parent0a3d5b577784e93ae1b21aff4c1f150eca25813a (diff)
downloadlinux-ece276de2a1f90b6a7836d388c372b9025345469.tar.xz
MIPS: Add MAC2008 Support
MAC2008 means the processor implemented IEEE754 style Fused MADD instruction. It was introduced in Release3 but removed in Release5. The toolchain support of MAC2008 have never landed except for Loongson processors. This patch aimed to disabled the MAC2008 if it's optional. For MAC2008 only processors, we corrected math-emu behavior to align with actual hardware behavior. Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> [paulburton@kernel.org: Fixup MIPSr2-r5 check in cpu_set_fpu_2008.] Signed-off-by: Paul Burton <paulburton@kernel.org> Cc: linux-mips@vger.kernel.org Cc: chenhc@lemote.com Cc: paul.burton@mips.com Cc: linux-kernel@vger.kernel.org
Diffstat (limited to 'arch/mips/include')
-rw-r--r--arch/mips/include/asm/cpu-features.h4
-rw-r--r--arch/mips/include/asm/cpu.h1
-rw-r--r--arch/mips/include/asm/mipsregs.h3
3 files changed, 8 insertions, 0 deletions
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 983a6a7f43a1..de44c92b1c1f 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -555,6 +555,10 @@
# define cpu_has_perf __opt(MIPS_CPU_PERF)
#endif
+#ifndef cpu_has_mac2008_only
+# define cpu_has_mac2008_only __opt(MIPS_CPU_MAC_2008_ONLY)
+#endif
+
#ifdef CONFIG_SMP
/*
* Some systems share FTLB RAMs between threads within a core (siblings in
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index 0e10ffcf0c1b..216a22916740 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -416,6 +416,7 @@ enum cpu_type_enum {
#define MIPS_CPU_MT_PER_TC_PERF_COUNTERS \
BIT_ULL(56) /* CPU has perf counters implemented per TC (MIPSMT ASE) */
#define MIPS_CPU_MMID BIT_ULL(57) /* CPU supports MemoryMapIDs */
+#define MIPS_CPU_MAC_2008_ONLY BIT_ULL(58) /* CPU Only support MAC2008 Fused multiply-add instruction */
/*
* CPU ASE encodings
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index 0d5a30988697..796fe47cfd17 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -1101,9 +1101,12 @@
/*
* Bits 22:20 of the FPU Status Register will be read as 0,
* and should be written as zero.
+ * MAC2008 was removed in Release 5 so we still treat it as
+ * reserved.
*/
#define FPU_CSR_RSVD (_ULCAST_(7) << 20)
+#define FPU_CSR_MAC2008 (_ULCAST_(1) << 20)
#define FPU_CSR_ABS2008 (_ULCAST_(1) << 19)
#define FPU_CSR_NAN2008 (_ULCAST_(1) << 18)