[U-Boot] [PATCH v2 08/15] riscv: Add a helper routine to print CPU information
Bin Meng
bmeng.cn at gmail.com
Tue Sep 11 04:37:33 UTC 2018
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 at gmail.com>
---
Changes in v2: None
arch/riscv/Makefile | 1 +
arch/riscv/cpu/Makefile | 5 ++
arch/riscv/cpu/cpu.c | 49 +++++++++++++++++
arch/riscv/include/asm/csr.h | 124 +++++++++++++++++++++++++++++++++++++++++++
4 files changed, 179 insertions(+)
create mode 100644 arch/riscv/cpu/Makefile
create mode 100644 arch/riscv/cpu/cpu.c
create mode 100644 arch/riscv/include/asm/csr.h
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 084888a..af432e1 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -5,5 +5,6 @@
head-y := arch/riscv/cpu/$(CPU)/start.o
+libs-y += arch/riscv/cpu/
libs-y += arch/riscv/cpu/$(CPU)/
libs-y += arch/riscv/lib/
diff --git a/arch/riscv/cpu/Makefile b/arch/riscv/cpu/Makefile
new file mode 100644
index 0000000..63de163
--- /dev/null
+++ b/arch/riscv/cpu/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
+
+obj-y += cpu.o
diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c
new file mode 100644
index 0000000..ae57fb8
--- /dev/null
+++ b/arch/riscv/cpu/cpu.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
+ */
+
+#include <common.h>
+#include <asm/csr.h>
+
+enum {
+ ISA_INVALID = 0,
+ ISA_32BIT,
+ ISA_64BIT,
+ ISA_128BIT
+};
+
+static const char * const isa_bits[] = {
+ [ISA_INVALID] = NULL,
+ [ISA_32BIT] = "32",
+ [ISA_64BIT] = "64",
+ [ISA_128BIT] = "128"
+};
+
+static inline bool supports_extension(char ext)
+{
+ return csr_read(misa) & (1 << (ext - 'a'));
+}
+
+int print_cpuinfo(void)
+{
+ char name[32];
+ char *s = name;
+ int bit;
+
+ s += sprintf(name, "rv");
+ bit = csr_read(misa) >> (sizeof(long) * 8 - 2);
+ s += sprintf(s, isa_bits[bit]);
+
+ supports_extension('i') ? *s++ = 'i' : 'r';
+ supports_extension('m') ? *s++ = 'm' : 'i';
+ supports_extension('a') ? *s++ = 'a' : 's';
+ supports_extension('f') ? *s++ = 'f' : 'c';
+ supports_extension('d') ? *s++ = 'd' : '-';
+ supports_extension('c') ? *s++ = 'c' : 'v';
+ *s++ = '\0';
+
+ printf("CPU: %s\n", name);
+
+ return 0;
+}
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 */
--
2.7.4
More information about the U-Boot
mailing list