riscv: remove riscv_isa_ext_keys[] array and related usage

All users have switched to riscv_has_extension_*, remove unused
definitions, vars and related setting code.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230128172856.3814-14-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/include/asm/hwcap.h

@@ -61,45 +61,13 @@ enum {
 
 extern unsigned long elf_hwcap;
 
-
-/*
- * This enum represents the logical ID for each RISC-V ISA extension static
- * keys. We can use static key to optimize code path if some ISA extensions
- * are available.
- * Entries are sorted alphabetically.
- */
-enum riscv_isa_ext_key {
-	RISCV_ISA_EXT_KEY_FPU,		/* For 'F' and 'D' */
-	RISCV_ISA_EXT_KEY_SVINVAL,
-	RISCV_ISA_EXT_KEY_ZIHINTPAUSE,
-	RISCV_ISA_EXT_KEY_MAX,
-};
-
 struct riscv_isa_ext_data {
 	/* Name of the extension displayed to userspace via /proc/cpuinfo */
 	char uprop[RISCV_ISA_EXT_NAME_LEN_MAX];
 	/* The logical ISA extension ID */
 	unsigned int isa_ext_id;
 };
 
-extern struct static_key_false riscv_isa_ext_keys[RISCV_ISA_EXT_KEY_MAX];
-
-static __always_inline int riscv_isa_ext2key(int num)
-{
-	switch (num) {
-	case RISCV_ISA_EXT_f:
-		return RISCV_ISA_EXT_KEY_FPU;
-	case RISCV_ISA_EXT_d:
-		return RISCV_ISA_EXT_KEY_FPU;
-	case RISCV_ISA_EXT_SVINVAL:
-		return RISCV_ISA_EXT_KEY_SVINVAL;
-	case RISCV_ISA_EXT_ZIHINTPAUSE:
-		return RISCV_ISA_EXT_KEY_ZIHINTPAUSE;
-	default:
-		return -EINVAL;
-	}
-}
-
 static __always_inline bool
 riscv_has_extension_likely(const unsigned long ext)
 {

arch/riscv/kernel/cpufeature.c

@@ -29,9 +29,6 @@ unsigned long elf_hwcap __read_mostly;
 /* Host ISA bitmap */
 static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
 
-DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
-EXPORT_SYMBOL(riscv_isa_ext_keys);
-
 /**
  * riscv_isa_extension_base() - Get base extension word
  *
@@ -267,12 +264,6 @@ void __init riscv_fill_hwcap(void)
 		if (elf_hwcap & BIT_MASK(i))
 			print_str[j++] = (char)('a' + i);
 	pr_info("riscv: ELF capabilities %s\n", print_str);
-
-	for_each_set_bit(i, riscv_isa, RISCV_ISA_EXT_MAX) {
-		j = riscv_isa_ext2key(i);
-		if (j >= 0)
-			static_branch_enable(&riscv_isa_ext_keys[j]);
-	}
 }
 
 #ifdef CONFIG_RISCV_ALTERNATIVE