riscv: Add a helper routine to print CPU information

This adds a helper routine to print CPU information. Currently
it prints all the instruction set extensions that the processor
core supports.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>

1 files changed, 124 insertions, 0 deletions

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
new file mode 100644
index 0000000..50fccea
--- /dev/null
+++ b/arch/riscv/include/asm/csr.h
@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2015 Regents of the University of California
+ *
+ * Taken from Linux arch/riscv/include/asm/csr.h
+ */
+
+#ifndef _ASM_RISCV_CSR_H
+#define _ASM_RISCV_CSR_H
+
+/* Status register flags */
+#define SR_SIE		_AC(0x00000002, UL) /* Supervisor Interrupt Enable */
+#define SR_SPIE		_AC(0x00000020, UL) /* Previous Supervisor IE */
+#define SR_SPP		_AC(0x00000100, UL) /* Previously Supervisor */
+#define SR_SUM		_AC(0x00040000, UL) /* Supervisor access User Memory */
+
+#define SR_FS		_AC(0x00006000, UL) /* Floating-point Status */
+#define SR_FS_OFF	_AC(0x00000000, UL)
+#define SR_FS_INITIAL	_AC(0x00002000, UL)
+#define SR_FS_CLEAN	_AC(0x00004000, UL)
+#define SR_FS_DIRTY	_AC(0x00006000, UL)
+
+#define SR_XS		_AC(0x00018000, UL) /* Extension Status */
+#define SR_XS_OFF	_AC(0x00000000, UL)
+#define SR_XS_INITIAL	_AC(0x00008000, UL)
+#define SR_XS_CLEAN	_AC(0x00010000, UL)
+#define SR_XS_DIRTY	_AC(0x00018000, UL)
+
+#ifndef CONFIG_64BIT
+#define SR_SD		_AC(0x80000000, UL) /* FS/XS dirty */
+#else
+#define SR_SD		_AC(0x8000000000000000, UL) /* FS/XS dirty */
+#endif
+
+/* SATP flags */
+#if __riscv_xlen == 32
+#define SATP_PPN	_AC(0x003FFFFF, UL)
+#define SATP_MODE_32	_AC(0x80000000, UL)
+#define SATP_MODE	SATP_MODE_32
+#else
+#define SATP_PPN	_AC(0x00000FFFFFFFFFFF, UL)
+#define SATP_MODE_39	_AC(0x8000000000000000, UL)
+#define SATP_MODE	SATP_MODE_39
+#endif
+
+/* Interrupt Enable and Interrupt Pending flags */
+#define SIE_SSIE	_AC(0x00000002, UL) /* Software Interrupt Enable */
+#define SIE_STIE	_AC(0x00000020, UL) /* Timer Interrupt Enable */
+
+#define EXC_INST_MISALIGNED	0
+#define EXC_INST_ACCESS		1
+#define EXC_BREAKPOINT		3
+#define EXC_LOAD_ACCESS		5
+#define EXC_STORE_ACCESS	7
+#define EXC_SYSCALL		8
+#define EXC_INST_PAGE_FAULT	12
+#define EXC_LOAD_PAGE_FAULT	13
+#define EXC_STORE_PAGE_FAULT	15
+
+#ifndef __ASSEMBLY__
+
+#define csr_swap(csr, val)					\
+({								\
+	unsigned long __v = (unsigned long)(val);		\
+	__asm__ __volatile__ ("csrrw %0, " #csr ", %1"		\
+			      : "=r" (__v) : "rK" (__v)		\
+			      : "memory");			\
+	__v;							\
+})
+
+#define csr_read(csr)						\
+({								\
+	register unsigned long __v;				\
+	__asm__ __volatile__ ("csrr %0, " #csr			\
+			      : "=r" (__v) :			\
+			      : "memory");			\
+	__v;							\
+})
+
+#define csr_write(csr, val)					\
+({								\
+	unsigned long __v = (unsigned long)(val);		\
+	__asm__ __volatile__ ("csrw " #csr ", %0"		\
+			      : : "rK" (__v)			\
+			      : "memory");			\
+})
+
+#define csr_read_set(csr, val)					\
+({								\
+	unsigned long __v = (unsigned long)(val);		\
+	__asm__ __volatile__ ("csrrs %0, " #csr ", %1"		\
+			      : "=r" (__v) : "rK" (__v)		\
+			      : "memory");			\
+	__v;							\
+})
+
+#define csr_set(csr, val)					\
+({								\
+	unsigned long __v = (unsigned long)(val);		\
+	__asm__ __volatile__ ("csrs " #csr ", %0"		\
+			      : : "rK" (__v)			\
+			      : "memory");			\
+})
+
+#define csr_read_clear(csr, val)				\
+({								\
+	unsigned long __v = (unsigned long)(val);		\
+	__asm__ __volatile__ ("csrrc %0, " #csr ", %1"		\
+			      : "=r" (__v) : "rK" (__v)		\
+			      : "memory");			\
+	__v;							\
+})
+
+#define csr_clear(csr, val)					\
+({								\
+	unsigned long __v = (unsigned long)(val);		\
+	__asm__ __volatile__ ("csrc " #csr ", %0"		\
+			      : : "rK" (__v)			\
+			      : "memory");			\
+})
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_RISCV_CSR_H */