[U-Boot] [PATCH 2/2] riscv: Access CSRs using CSR numbers
Rick Chen
rickchen36 at gmail.com
Tue Jul 23 02:27:21 UTC 2019
Hi Lukas
> > From: Auer, Lukas [mailto:lukas.auer at aisec.fraunhofer.de]
> > Sent: Thursday, July 18, 2019 4:53 PM
> > To: Rick Jian-Zhi Chen(陳建志); u-boot at lists.denx.de; bmeng.cn at gmail.com;
> > anup.patel at wdc.com
> > Subject: Re: [PATCH 2/2] riscv: Access CSRs using CSR numbers
> >
> > Hi Bin,
> >
> > On Wed, 2019-07-10 at 23:43 -0700, Bin Meng wrote:
> > > 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 at gmail.com>
> > > ---
> > >
> > > arch/riscv/cpu/cpu.c | 9 +-
> > > arch/riscv/cpu/start.S | 3 +-
> > > arch/riscv/include/asm/csr.h | 12 ++
> > > arch/riscv/include/asm/encoding.h | 238
> > > +-------------------------------------
> > > 4 files changed, 19 insertions(+), 243 deletions(-)
> > >
> > > diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c index
> > > e9a8b43..5ca1857 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
> > > 60ac8c6..e06db40 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 1a6bcfc..d152074 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 772668c..c450eb9 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
> > > -
> >
> > Why are you removing all CSR_* definitions here?
> >
> > The patch looks good and it is a very good idea to only use CSR numbers. There
> > are still two places left, where we are using CSR names.
> >
> > The first is in the MODE_PREFIX macro. That should only be a matter of changing
> > it to CSR_M/S##__suffix and capitalizing the suffix in all uses of the macro.
> >
> > The second one is in cpu/ax25/cache.c. Rick, can you maybe add a patch to your
> > cache series to convert that file to using CSR numbers instead of names? That
> > would also allow us to build the board in Travis with the cache enabled.
OK.
I will prepare a patch to use CSR numbers instead of names.
Thanks
Rick
> >
> > Thanks,
> > Lukas
> >
> > > #endif /* __riscv */
> > >
> > > #endif /* RISCV_CSR_ENCODING_H */
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