1 files changed, 112 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
new file mode 100644
index 000000000..b22525290
--- /dev/null
+++ b/arch/riscv/include/asm/hwcap.h
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copied from arch/arm64/include/asm/hwcap.h
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2017 SiFive
+ */
+#ifndef _ASM_RISCV_HWCAP_H
+#define _ASM_RISCV_HWCAP_H
+
+#include <asm/errno.h>
+#include <linux/bits.h>
+#include <uapi/asm/hwcap.h>
+
+#ifndef __ASSEMBLY__
+#include <linux/jump_label.h>
+/*
+ * This yields a mask that user programs can use to figure out what
+ * instruction set this cpu supports.
+ */
+#define ELF_HWCAP		(elf_hwcap)
+
+enum {
+	CAP_HWCAP = 1,
+};
+
+extern unsigned long elf_hwcap;
+
+#define RISCV_ISA_EXT_a		('a' - 'a')
+#define RISCV_ISA_EXT_c		('c' - 'a')
+#define RISCV_ISA_EXT_d		('d' - 'a')
+#define RISCV_ISA_EXT_f		('f' - 'a')
+#define RISCV_ISA_EXT_h		('h' - 'a')
+#define RISCV_ISA_EXT_i		('i' - 'a')
+#define RISCV_ISA_EXT_m		('m' - 'a')
+#define RISCV_ISA_EXT_s		('s' - 'a')
+#define RISCV_ISA_EXT_u		('u' - 'a')
+
+/*
+ * Increse this to higher value as kernel support more ISA extensions.
+ */
+#define RISCV_ISA_EXT_MAX	64
+#define RISCV_ISA_EXT_NAME_LEN_MAX 32
+
+/* The base ID for multi-letter ISA extensions */
+#define RISCV_ISA_EXT_BASE 26
+
+/*
+ * This enum represent the logical ID for each multi-letter RISC-V ISA extension.
+ * The logical ID should start from RISCV_ISA_EXT_BASE and must not exceed
+ * RISCV_ISA_EXT_MAX. 0-25 range is reserved for single letter
+ * extensions while all the multi-letter extensions should define the next
+ * available logical extension id.
+ */
+enum riscv_isa_ext_id {
+	RISCV_ISA_EXT_SSCOFPMF = RISCV_ISA_EXT_BASE,
+	RISCV_ISA_EXT_SVPBMT,
+	RISCV_ISA_EXT_ZICBOM,
+	RISCV_ISA_EXT_ZIHINTPAUSE,
+	RISCV_ISA_EXT_SSTC,
+	RISCV_ISA_EXT_SVINVAL,
+	RISCV_ISA_EXT_ID_MAX = RISCV_ISA_EXT_MAX,
+};
+
+/*
+ * 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.
+ */
+enum riscv_isa_ext_key {
+	RISCV_ISA_EXT_KEY_FPU,		/* For 'F' and 'D' */
+	RISCV_ISA_EXT_KEY_ZIHINTPAUSE,
+	RISCV_ISA_EXT_KEY_SVINVAL,
+	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_ZIHINTPAUSE:
+		return RISCV_ISA_EXT_KEY_ZIHINTPAUSE;
+	case RISCV_ISA_EXT_SVINVAL:
+		return RISCV_ISA_EXT_KEY_SVINVAL;
+	default:
+		return -EINVAL;
+	}
+}
+
+unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap);
+
+#define riscv_isa_extension_mask(ext) BIT_MASK(RISCV_ISA_EXT_##ext)
+
+bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit);
+#define riscv_isa_extension_available(isa_bitmap, ext)	\
+	__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext)
+
+#endif
+
+#endif /* _ASM_RISCV_HWCAP_H */