Re: [PATCH v2 04/14] xen/riscv: add <asm/csr.h> header

[Alistair Francis <alistair23@xxxxxxxxx>]

On Sat, Jan 28, 2023 at 12:00 AM Oleksii Kurochko
<oleksii.kurochko@xxxxxxxxx> wrote:
>
> The following changes were made in comparison with <asm/csr.h> from
> Linux:
>   * remove all defines as they are defined in riscv_encoding.h
>   * leave only csr_* macros
>
> Origin: https://github.com/torvalds/linux.git 2475bf0250de
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>

Reviewed-by: Alistair Francis <alistair.francis@xxxxxxx>

Alistair

> ---
> Changes in V2:
>   - Minor refactoring mentioned in the commit message, switch tabs to
>     spaces and refactor things around __asm__ __volatile__.
>   - Update the commit message and add "Origin:" tag.
> ---
>  xen/arch/riscv/include/asm/csr.h | 84 ++++++++++++++++++++++++++++++++
>  1 file changed, 84 insertions(+)
>  create mode 100644 xen/arch/riscv/include/asm/csr.h
>
> diff --git a/xen/arch/riscv/include/asm/csr.h 
> b/xen/arch/riscv/include/asm/csr.h
> new file mode 100644
> index 0000000000..4275cf6515
> --- /dev/null
> +++ b/xen/arch/riscv/include/asm/csr.h
> @@ -0,0 +1,84 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-only
> + *
> + * Copyright (C) 2015 Regents of the University of California
> + */
> +
> +#ifndef _ASM_RISCV_CSR_H
> +#define _ASM_RISCV_CSR_H
> +
> +#include <asm/asm.h>
> +#include <xen/const.h>
> +#include <asm/riscv_encoding.h>
> +
> +#ifndef __ASSEMBLY__
> +
> +#define csr_read(csr)                                           \
> +({                                                              \
> +    register unsigned long __v;                                 \
> +    __asm__ __volatile__ (  "csrr %0, " __ASM_STR(csr)          \
> +                            : "=r" (__v)                        \
> +                            : : "memory" );                     \
> +    __v;                                                        \
> +})
> +
> +#define csr_write(csr, val)                                     \
> +({                                                              \
> +    unsigned long __v = (unsigned long)(val);                   \
> +    __asm__ __volatile__ (  "csrw " __ASM_STR(csr) ", %0"       \
> +                            : /* no outputs */                  \
> +                            : "rK" (__v)                        \
> +                            : "memory" );                       \
> +})
> +
> +#define csr_swap(csr, val)                                      \
> +({                                                              \
> +    unsigned long __v = (unsigned long)(val);                   \
> +    __asm__ __volatile__ (  "csrrw %0, " __ASM_STR(csr) ", %1"  \
> +                            : "=r" (__v)                        \
> +                            : "rK" (__v)                        \
> +                            : "memory" );                       \
> +    __v;                                                        \
> +})
> +
> +#define csr_read_set(csr, val)                                  \
> +({                                                              \
> +    unsigned long __v = (unsigned long)(val);                   \
> +    __asm__ __volatile__ (  "csrrs %0, " __ASM_STR(csr) ", %1"  \
> +                            : "=r" (__v)                        \
> +                            : "rK" (__v)                        \
> +                            : "memory" );                       \
> +    __v;                                                        \
> +})
> +
> +#define csr_set(csr, val)                                       \
> +({                                                              \
> +    unsigned long __v = (unsigned long)(val);                   \
> +    __asm__ __volatile__ (  "csrs " __ASM_STR(csr) ", %0"       \
> +                            : /* no outputs */                  \
> +                            : "rK" (__v)                        \
> +                            : "memory" );                       \
> +})
> +
> +#define csr_read_clear(csr, val)                                \
> +({                                                              \
> +    unsigned long __v = (unsigned long)(val);                   \
> +    __asm__ __volatile__ (  "csrrc %0, " __ASM_STR(csr) ", %1"  \
> +                            : "=r" (__v)                        \
> +                            : "rK" (__v)                        \
> +                            : "memory" );                       \
> +    __v;                                                        \
> +})
> +
> +#define csr_clear(csr, val)                                     \
> +({                                                              \
> +    unsigned long __v = (unsigned long)(val);                   \
> +    __asm__ __volatile__ (  "csrc " __ASM_STR(csr) ", %0"       \
> +                            : /*no outputs */                   \
> +                            : "rK" (__v)                        \
> +                            : "memory" );                       \
> +})
> +
> +#endif /* __ASSEMBLY__ */
> +
> +#endif /* _ASM_RISCV_CSR_H */
> --
> 2.39.0
>
>