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authorPaul Burton <paul.burton@mips.com>2018-11-26 18:58:40 +0000
committerPaul Burton <paul.burton@mips.com>2018-11-26 22:49:20 -0800
commit1aeba347b3a90a8b22f1c3eed0dcfba38bb8dbb8 (patch)
tree83491b85b7a0b5b81dd483fa2a58886c3f19bdce
parentf08153186ca5023c1672aa6417ee4fc748ac5901 (diff)
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MIPS: Hardcode cpu_has_mips* where target ISA allows
In the same vein as commit 93e01942a6eb ("MIPS: Hardcode cpu_has_* where known at compile time due to ISA"), we can use our knowledge of the ISA being targeted by the kernel build to make cpu_has_mips* macros compile-time constant in some cases. This allows the compiler greater opportunity to optimize out code which will never execute. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/21245/ Cc: linux-mips@linux-mips.org
-rw-r--r--arch/mips/include/asm/cpu-features.h35
1 files changed, 24 insertions, 11 deletions
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index ca348356f76f..701e525641b8 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -15,6 +15,7 @@
#include <cpu-feature-overrides.h>
#define __ase(ase) (cpu_data[0].ases & (ase))
+#define __isa(isa) (cpu_data[0].isa_level & (isa))
#define __opt(opt) (cpu_data[0].options & (opt))
/*
@@ -53,6 +54,18 @@
#define __isa_lt_and_opt(isa, opt) ((MIPS_ISA_REV < (isa)) && __opt(opt))
/*
+ * Similarly allow for ISA level checks that take into account knowledge of the
+ * ISA targeted by the kernel build, provided by MIPS_ISA_REV.
+ */
+#define __isa_ge_and_flag(isa, flag) ((MIPS_ISA_REV >= (isa)) && __isa(flag))
+#define __isa_ge_or_flag(isa, flag) ((MIPS_ISA_REV >= (isa)) || __isa(flag))
+#define __isa_lt_and_flag(isa, flag) ((MIPS_ISA_REV < (isa)) && __isa(flag))
+#define __isa_range(ge, lt) \
+ ((MIPS_ISA_REV >= (ge)) && (MIPS_ISA_REV < (lt)))
+#define __isa_range_or_flag(ge, lt, flag) \
+ (__isa_range(ge, lt) || ((MIPS_ISA_REV < (lt)) && __isa(flag)))
+
+/*
* SMP assumption: Options of CPU 0 are a superset of all processors.
* This is true for all known MIPS systems.
*/
@@ -254,37 +267,37 @@
#endif
#ifndef cpu_has_mips_1
-# define cpu_has_mips_1 (!cpu_has_mips_r6)
+# define cpu_has_mips_1 (MIPS_ISA_REV < 6)
#endif
#ifndef cpu_has_mips_2
-# define cpu_has_mips_2 (cpu_data[0].isa_level & MIPS_CPU_ISA_II)
+# define cpu_has_mips_2 __isa_lt_and_flag(6, MIPS_CPU_ISA_II)
#endif
#ifndef cpu_has_mips_3
-# define cpu_has_mips_3 (cpu_data[0].isa_level & MIPS_CPU_ISA_III)
+# define cpu_has_mips_3 __isa_lt_and_flag(6, MIPS_CPU_ISA_III)
#endif
#ifndef cpu_has_mips_4
-# define cpu_has_mips_4 (cpu_data[0].isa_level & MIPS_CPU_ISA_IV)
+# define cpu_has_mips_4 __isa_lt_and_flag(6, MIPS_CPU_ISA_IV)
#endif
#ifndef cpu_has_mips_5
-# define cpu_has_mips_5 (cpu_data[0].isa_level & MIPS_CPU_ISA_V)
+# define cpu_has_mips_5 __isa_lt_and_flag(6, MIPS_CPU_ISA_V)
#endif
#ifndef cpu_has_mips32r1
-# define cpu_has_mips32r1 (cpu_data[0].isa_level & MIPS_CPU_ISA_M32R1)
+# define cpu_has_mips32r1 __isa_range_or_flag(1, 6, MIPS_CPU_ISA_M32R1)
#endif
#ifndef cpu_has_mips32r2
-# define cpu_has_mips32r2 (cpu_data[0].isa_level & MIPS_CPU_ISA_M32R2)
+# define cpu_has_mips32r2 __isa_range_or_flag(2, 6, MIPS_CPU_ISA_M32R2)
#endif
#ifndef cpu_has_mips32r6
-# define cpu_has_mips32r6 (cpu_data[0].isa_level & MIPS_CPU_ISA_M32R6)
+# define cpu_has_mips32r6 __isa_ge_or_flag(6, MIPS_CPU_ISA_M32R6)
#endif
#ifndef cpu_has_mips64r1
-# define cpu_has_mips64r1 (cpu_data[0].isa_level & MIPS_CPU_ISA_M64R1)
+# define cpu_has_mips64r1 __isa_range_or_flag(1, 6, MIPS_CPU_ISA_M64R1)
#endif
#ifndef cpu_has_mips64r2
-# define cpu_has_mips64r2 (cpu_data[0].isa_level & MIPS_CPU_ISA_M64R2)
+# define cpu_has_mips64r2 __isa_range_or_flag(2, 6, MIPS_CPU_ISA_M64R2)
#endif
#ifndef cpu_has_mips64r6
-# define cpu_has_mips64r6 (cpu_data[0].isa_level & MIPS_CPU_ISA_M64R6)
+# define cpu_has_mips64r6 __isa_ge_and_flag(6, MIPS_CPU_ISA_M64R6)
#endif
/*