riscv: Access CSRs using CSR numbers

We should prefer accessing CSRs using their CSR numbers
because:
1. It compiles fine with older toolchains.
2. We can use latest CSR names in #define macro names of CSR
   numbers as-per RISC-V spec.
3. We can access newly added CSRs even if toolchain does not
   recognize newly added CSRs by name.

This commit is inspired from Linux kernel commit a3182c91ef4e
("RISC-V: Access CSRs using CSR numbers").

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Rick Chen <rick@andestech.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>

4 files changed, 19 insertions, 243 deletions

diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c
index e9a8b437ed..5ca185745e 100644
--- a/arch/riscv/cpu/cpu.c
+++ b/arch/riscv/cpu/cpu.c
@@ -7,7 +7,6 @@
 #include <cpu.h>
 #include <dm.h>
 #include <log.h>
-#include <asm/csr.h>
 #include <asm/encoding.h>
 #include <dm/uclass-internal.h>
 
@@ -48,7 +47,7 @@ static inline bool supports_extension(char ext)
 	return false;
 #else  /* !CONFIG_CPU */
 #ifdef CONFIG_RISCV_MMODE
-	return csr_read(misa) & (1 << (ext - 'a'));
+	return csr_read(CSR_MISA) & (1 << (ext - 'a'));
 #else  /* !CONFIG_RISCV_MMODE */
 #warning "There is no way to determine the available extensions in S-mode."
 #warning "Please convert your board to use the RISC-V CPU driver."
@@ -82,7 +81,7 @@ int arch_cpu_init_dm(void)
 	/* Enable FPU */
 	if (supports_extension('d') || supports_extension('f')) {
 		csr_set(MODE_PREFIX(status), MSTATUS_FS);
-		csr_write(fcsr, 0);
+		csr_write(CSR_FCSR, 0);
 	}
 
 	if (CONFIG_IS_ENABLED(RISCV_MMODE)) {
@@ -90,11 +89,11 @@ int arch_cpu_init_dm(void)
 		 * Enable perf counters for cycle, time,
 		 * and instret counters only
 		 */
-		csr_write(mcounteren, GENMASK(2, 0));
+		csr_write(CSR_MCOUNTEREN, GENMASK(2, 0));
 
 		/* Disable paging */
 		if (supports_extension('s'))
-			csr_write(satp, 0);
+			csr_write(CSR_SATP, 0);
 	}
 
 	return 0;
diff --git a/arch/riscv/cpu/start.S b/arch/riscv/cpu/start.S
index 60ac8c621e..e06db404f5 100644
--- a/arch/riscv/cpu/start.S
+++ b/arch/riscv/cpu/start.S
@@ -13,7 +13,6 @@
 #include <config.h>
 #include <common.h>
 #include <elf.h>
-#include <asm/csr.h>
 #include <asm/encoding.h>
 #include <generated/asm-offsets.h>
 
@@ -41,7 +40,7 @@ secondary_harts_relocation_error:
 .globl _start
 _start:
 #ifdef CONFIG_RISCV_MMODE
-	csrr	a0, mhartid
+	csrr	a0, CSR_MHARTID
 #endif
 
 	/* save hart id and dtb pointer */
diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 1a6bcfc334..d1520743a2 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -75,6 +75,7 @@
 #define SIE_STIE		(_AC(0x1, UL) << IRQ_S_TIMER)
 #define SIE_SEIE		(_AC(0x1, UL) << IRQ_S_EXT)
 
+#define CSR_FCSR		0x003
 #define CSR_CYCLE		0xc00
 #define CSR_TIME		0xc01
 #define CSR_INSTRET		0xc02
@@ -88,9 +89,20 @@
 #define CSR_STVAL		0x143
 #define CSR_SIP			0x144
 #define CSR_SATP		0x180
+#define CSR_MSTATUS		0x300
+#define CSR_MISA		0x301
+#define CSR_MIE			0x304
+#define CSR_MTVEC		0x305
+#define CSR_MCOUNTEREN		0x306
+#define CSR_MSCRATCH		0x340
+#define CSR_MEPC		0x341
+#define CSR_MCAUSE		0x342
+#define CSR_MTVAL		0x343
+#define CSR_MIP			0x344
 #define CSR_CYCLEH		0xc80
 #define CSR_TIMEH		0xc81
 #define CSR_INSTRETH		0xc82
+#define CSR_MHARTID		0xf14
 
 #ifndef __ASSEMBLY__
 
diff --git a/arch/riscv/include/asm/encoding.h b/arch/riscv/include/asm/encoding.h
index 772668c74e..c450eb9103 100644
--- a/arch/riscv/include/asm/encoding.h
+++ b/arch/riscv/include/asm/encoding.h
@@ -7,6 +7,8 @@
 #ifndef RISCV_CSR_ENCODING_H
 #define RISCV_CSR_ENCODING_H
 
+#include <asm/csr.h>
+
 #ifdef CONFIG_RISCV_SMODE
 #define MODE_PREFIX(__suffix)	s##__suffix
 #else
@@ -49,13 +51,10 @@
 #define SSTATUS64_SD	0x8000000000000000
 
 #define MIP_SSIP	BIT(IRQ_S_SOFT)
-#define MIP_HSIP	BIT(IRQ_H_SOFT)
 #define MIP_MSIP	BIT(IRQ_M_SOFT)
 #define MIP_STIP	BIT(IRQ_S_TIMER)
-#define MIP_HTIP	BIT(IRQ_H_TIMER)
 #define MIP_MTIP	BIT(IRQ_M_TIMER)
 #define MIP_SEIP	BIT(IRQ_S_EXT)
-#define MIP_HEIP	BIT(IRQ_H_EXT)
 #define MIP_MEIP	BIT(IRQ_M_EXT)
 
 #define SIP_SSIP	MIP_SSIP
@@ -73,18 +72,6 @@
 #define VM_SV39		9
 #define VM_SV48		10
 
-#define IRQ_S_SOFT	1
-#define IRQ_H_SOFT	2
-#define IRQ_M_SOFT	3
-#define IRQ_S_TIMER	5
-#define IRQ_H_TIMER	6
-#define IRQ_M_TIMER	7
-#define IRQ_S_EXT	9
-#define IRQ_H_EXT	10
-#define IRQ_M_EXT	11
-#define IRQ_COP		12
-#define IRQ_HOST	13
-
 #define CAUSE_MISALIGNED_FETCH		0
 #define CAUSE_FETCH_ACCESS		1
 #define CAUSE_ILLEGAL_INSTRUCTION	2
@@ -167,227 +154,6 @@
 #define RISCV_PGSHIFT 12
 #define RISCV_PGSIZE BIT(RISCV_PGSHIFT)
 
-/* CSR numbers */
-#define CSR_FFLAGS		0x1
-#define CSR_FRM			0x2
-#define CSR_FCSR		0x3
-
-#define CSR_SSTATUS		0x100
-#define CSR_SEDELEG		0x102
-#define CSR_SIDELEG		0x103
-#define CSR_SIE			0x104
-#define CSR_STVEC		0x105
-#define CSR_SCOUNTEREN		0x106
-#define CSR_SSCRATCH		0x140
-#define CSR_SEPC		0x141
-#define CSR_SCAUSE		0x142
-#define CSR_STVAL		0x143
-#define CSR_SIP			0x144
-#define CSR_SATP		0x180
-
-#define CSR_MSTATUS		0x300
-#define CSR_MISA		0x301
-#define CSR_MEDELEG		0x302
-#define CSR_MIDELEG		0x303
-#define CSR_MIE			0x304
-#define CSR_MTVEC		0x305
-#define CSR_MCOUNTEREN		0x306
-#define CSR_MHPMEVENT3		0x323
-#define CSR_MHPMEVENT4		0x324
-#define CSR_MHPMEVENT5		0x325
-#define CSR_MHPMEVENT6		0x326
-#define CSR_MHPMEVENT7		0x327
-#define CSR_MHPMEVENT8		0x328
-#define CSR_MHPMEVENT9		0x329
-#define CSR_MHPMEVENT10		0x32a
-#define CSR_MHPMEVENT11		0x32b
-#define CSR_MHPMEVENT12		0x32c
-#define CSR_MHPMEVENT13		0x32d
-#define CSR_MHPMEVENT14		0x32e
-#define CSR_MHPMEVENT15		0x32f
-#define CSR_MHPMEVENT16		0x330
-#define CSR_MHPMEVENT17		0x331
-#define CSR_MHPMEVENT18		0x332
-#define CSR_MHPMEVENT19		0x333
-#define CSR_MHPMEVENT20		0x334
-#define CSR_MHPMEVENT21		0x335
-#define CSR_MHPMEVENT22		0x336
-#define CSR_MHPMEVENT23		0x337
-#define CSR_MHPMEVENT24		0x338
-#define CSR_MHPMEVENT25		0x339
-#define CSR_MHPMEVENT26		0x33a
-#define CSR_MHPMEVENT27		0x33b
-#define CSR_MHPMEVENT28		0x33c
-#define CSR_MHPMEVENT29		0x33d
-#define CSR_MHPMEVENT30		0x33e
-#define CSR_MHPMEVENT31		0x33f
-#define CSR_MSCRATCH		0x340
-#define CSR_MEPC		0x341
-#define CSR_MCAUSE		0x342
-#define CSR_MTVAL		0x343
-#define CSR_MIP			0x344
-#define CSR_PMPCFG0		0x3a0
-#define CSR_PMPCFG1		0x3a1
-#define CSR_PMPCFG2		0x3a2
-#define CSR_PMPCFG3		0x3a3
-#define CSR_PMPADDR0		0x3b0
-#define CSR_PMPADDR1		0x3b1
-#define CSR_PMPADDR2		0x3b2
-#define CSR_PMPADDR3		0x3b3
-#define CSR_PMPADDR4		0x3b4
-#define CSR_PMPADDR5		0x3b5
-#define CSR_PMPADDR6		0x3b6
-#define CSR_PMPADDR7		0x3b7
-#define CSR_PMPADDR8		0x3b8
-#define CSR_PMPADDR9		0x3b9
-#define CSR_PMPADDR10		0x3ba
-#define CSR_PMPADDR11		0x3bb
-#define CSR_PMPADDR12		0x3bc
-#define CSR_PMPADDR13		0x3bd
-#define CSR_PMPADDR14		0x3be
-#define CSR_PMPADDR15		0x3bf
-
-#define CSR_TSELECT		0x7a0
-#define CSR_TDATA1		0x7a1
-#define CSR_TDATA2		0x7a2
-#define CSR_TDATA3		0x7a3
-#define CSR_DCSR		0x7b0
-#define CSR_DPC			0x7b1
-#define CSR_DSCRATCH		0x7b2
-
-#define CSR_MCYCLE		0xb00
-#define CSR_MINSTRET		0xb02
-#define CSR_MHPMCOUNTER3	0xb03
-#define CSR_MHPMCOUNTER4	0xb04
-#define CSR_MHPMCOUNTER5	0xb05
-#define CSR_MHPMCOUNTER6	0xb06
-#define CSR_MHPMCOUNTER7	0xb07
-#define CSR_MHPMCOUNTER8	0xb08
-#define CSR_MHPMCOUNTER9	0xb09
-#define CSR_MHPMCOUNTER10	0xb0a
-#define CSR_MHPMCOUNTER11	0xb0b
-#define CSR_MHPMCOUNTER12	0xb0c
-#define CSR_MHPMCOUNTER13	0xb0d
-#define CSR_MHPMCOUNTER14	0xb0e
-#define CSR_MHPMCOUNTER15	0xb0f
-#define CSR_MHPMCOUNTER16	0xb10
-#define CSR_MHPMCOUNTER17	0xb11
-#define CSR_MHPMCOUNTER18	0xb12
-#define CSR_MHPMCOUNTER19	0xb13
-#define CSR_MHPMCOUNTER20	0xb14
-#define CSR_MHPMCOUNTER21	0xb15
-#define CSR_MHPMCOUNTER22	0xb16
-#define CSR_MHPMCOUNTER23	0xb17
-#define CSR_MHPMCOUNTER24	0xb18
-#define CSR_MHPMCOUNTER25	0xb19
-#define CSR_MHPMCOUNTER26	0xb1a
-#define CSR_MHPMCOUNTER27	0xb1b
-#define CSR_MHPMCOUNTER28	0xb1c
-#define CSR_MHPMCOUNTER29	0xb1d
-#define CSR_MHPMCOUNTER30	0xb1e
-#define CSR_MHPMCOUNTER31	0xb1f
-#define CSR_MCYCLEH		0xb80
-#define CSR_MINSTRETH		0xb82
-#define CSR_MHPMCOUNTER3H	0xb83
-#define CSR_MHPMCOUNTER4H	0xb84
-#define CSR_MHPMCOUNTER5H	0xb85
-#define CSR_MHPMCOUNTER6H	0xb86
-#define CSR_MHPMCOUNTER7H	0xb87
-#define CSR_MHPMCOUNTER8H	0xb88
-#define CSR_MHPMCOUNTER9H	0xb89
-#define CSR_MHPMCOUNTER10H	0xb8a
-#define CSR_MHPMCOUNTER11H	0xb8b
-#define CSR_MHPMCOUNTER12H	0xb8c
-#define CSR_MHPMCOUNTER13H	0xb8d
-#define CSR_MHPMCOUNTER14H	0xb8e
-#define CSR_MHPMCOUNTER15H	0xb8f
-#define CSR_MHPMCOUNTER16H	0xb90
-#define CSR_MHPMCOUNTER17H	0xb91
-#define CSR_MHPMCOUNTER18H	0xb92
-#define CSR_MHPMCOUNTER19H	0xb93
-#define CSR_MHPMCOUNTER20H	0xb94
-#define CSR_MHPMCOUNTER21H	0xb95
-#define CSR_MHPMCOUNTER22H	0xb96
-#define CSR_MHPMCOUNTER23H	0xb97
-#define CSR_MHPMCOUNTER24H	0xb98
-#define CSR_MHPMCOUNTER25H	0xb99
-#define CSR_MHPMCOUNTER26H	0xb9a
-#define CSR_MHPMCOUNTER27H	0xb9b
-#define CSR_MHPMCOUNTER28H	0xb9c
-#define CSR_MHPMCOUNTER29H	0xb9d
-#define CSR_MHPMCOUNTER30H	0xb9e
-#define CSR_MHPMCOUNTER31H	0xb9f
-
-#define CSR_CYCLE		0xc00
-#define CSR_TIME		0xc01
-#define CSR_INSTRET		0xc02
-#define CSR_HPMCOUNTER3		0xc03
-#define CSR_HPMCOUNTER4		0xc04
-#define CSR_HPMCOUNTER5		0xc05
-#define CSR_HPMCOUNTER6		0xc06
-#define CSR_HPMCOUNTER7		0xc07
-#define CSR_HPMCOUNTER8		0xc08
-#define CSR_HPMCOUNTER9		0xc09
-#define CSR_HPMCOUNTER10	0xc0a
-#define CSR_HPMCOUNTER11	0xc0b
-#define CSR_HPMCOUNTER12	0xc0c
-#define CSR_HPMCOUNTER13	0xc0d
-#define CSR_HPMCOUNTER14	0xc0e
-#define CSR_HPMCOUNTER15	0xc0f
-#define CSR_HPMCOUNTER16	0xc10
-#define CSR_HPMCOUNTER17	0xc11
-#define CSR_HPMCOUNTER18	0xc12
-#define CSR_HPMCOUNTER19	0xc13
-#define CSR_HPMCOUNTER20	0xc14
-#define CSR_HPMCOUNTER21	0xc15
-#define CSR_HPMCOUNTER22	0xc16
-#define CSR_HPMCOUNTER23	0xc17
-#define CSR_HPMCOUNTER24	0xc18
-#define CSR_HPMCOUNTER25	0xc19
-#define CSR_HPMCOUNTER26	0xc1a
-#define CSR_HPMCOUNTER27	0xc1b
-#define CSR_HPMCOUNTER28	0xc1c
-#define CSR_HPMCOUNTER29	0xc1d
-#define CSR_HPMCOUNTER30	0xc1e
-#define CSR_HPMCOUNTER31	0xc1f
-#define CSR_CYCLEH		0xc80
-#define CSR_TIMEH		0xc81
-#define CSR_INSTRETH		0xc82
-#define CSR_HPMCOUNTER3H	0xc83
-#define CSR_HPMCOUNTER4H	0xc84
-#define CSR_HPMCOUNTER5H	0xc85
-#define CSR_HPMCOUNTER6H	0xc86
-#define CSR_HPMCOUNTER7H	0xc87
-#define CSR_HPMCOUNTER8H	0xc88
-#define CSR_HPMCOUNTER9H	0xc89
-#define CSR_HPMCOUNTER10H	0xc8a
-#define CSR_HPMCOUNTER11H	0xc8b
-#define CSR_HPMCOUNTER12H	0xc8c
-#define CSR_HPMCOUNTER13H	0xc8d
-#define CSR_HPMCOUNTER14H	0xc8e
-#define CSR_HPMCOUNTER15H	0xc8f
-#define CSR_HPMCOUNTER16H	0xc90
-#define CSR_HPMCOUNTER17H	0xc91
-#define CSR_HPMCOUNTER18H	0xc92
-#define CSR_HPMCOUNTER19H	0xc93
-#define CSR_HPMCOUNTER20H	0xc94
-#define CSR_HPMCOUNTER21H	0xc95
-#define CSR_HPMCOUNTER22H	0xc96
-#define CSR_HPMCOUNTER23H	0xc97
-#define CSR_HPMCOUNTER24H	0xc98
-#define CSR_HPMCOUNTER25H	0xc99
-#define CSR_HPMCOUNTER26H	0xc9a
-#define CSR_HPMCOUNTER27H	0xc9b
-#define CSR_HPMCOUNTER28H	0xc9c
-#define CSR_HPMCOUNTER29H	0xc9d
-#define CSR_HPMCOUNTER30H	0xc9e
-#define CSR_HPMCOUNTER31H	0xc9f
-
-#define CSR_MVENDORID		0xf11
-#define CSR_MARCHID		0xf12
-#define CSR_MIMPID		0xf13
-#define CSR_MHARTID		0xf14
-
 #endif /* __riscv */
 
 #endif /* RISCV_CSR_ENCODING_H */