[PATCH v1 1/1] lib: sbi: Add support for smcsrind and smcdeleg

[Anup Patel]

On Sat, Feb 17, 2024 at 5:36 AM Atish Patra <atishp at rivosinc.com> wrote:
>
> Smcsrind allows generic indirect CSR access mechanism while
> Smcdeleg allows delegating hpmcounters in Supervisor mode.
>
> Enable both extensions and set the appropriate bits in mstateen
> and menvcfg.
>
> Co-developed-by: Kaiwen Xue <kaiwenxue1 at gmail.com>
> Signed-off-by: Atish Patra <atishp at rivosinc.com>

LGTM.

Reviewed-by: Anup Patel <anup at brainfault.org>

Applied this patch to the riscv/opensbi repo.

Thanks,
Anup

> ---
>  include/sbi/riscv_encoding.h | 25 ++++++++++++++++++++++---
>  include/sbi/sbi_hart.h       |  8 ++++++++
>  lib/sbi/sbi_hart.c           | 16 ++++++++++++----
>  3 files changed, 42 insertions(+), 7 deletions(-)
>
> diff --git a/include/sbi/riscv_encoding.h b/include/sbi/riscv_encoding.h
> index e74cc0df1c40..57aabd665589 100644
> --- a/include/sbi/riscv_encoding.h
> +++ b/include/sbi/riscv_encoding.h
> @@ -209,6 +209,7 @@
>
>  #define ENVCFG_STCE                    (_ULL(1) << 63)
>  #define ENVCFG_PBMTE                   (_ULL(1) << 62)
> +#define ENVCFG_CDE                     (_UL(1) << 60)
>  #define ENVCFG_CBZE                    (_UL(1) << 7)
>  #define ENVCFG_CBCFE                   (_UL(1) << 6)
>  #define ENVCFG_CBIE_SHIFT              4
> @@ -314,6 +315,9 @@
>  /* Supervisor Configuration */
>  #define CSR_SENVCFG                    0x10a
>
> +/* Supervisor Conter Inhibit */
> +#define CSR_SCOUNTINHIBIT              0x120
> +
>  /* Supervisor Trap Handling */
>  #define CSR_SSCRATCH                   0x140
>  #define CSR_SEPC                       0x141
> @@ -328,9 +332,14 @@
>  /* Supervisor Protection and Translation */
>  #define CSR_SATP                       0x180
>
> -/* Supervisor-Level Window to Indirectly Accessed Registers (AIA) */
> +/* Supervisor Indirect Register Alias */
>  #define CSR_SISELECT                   0x150
>  #define CSR_SIREG                      0x151
> +#define CSR_SIREG2                     0x152
> +#define CSR_SIREG3                     0x153
> +#define CSR_SIREG4                     0x155
> +#define CSR_SIREG5                     0x156
> +#define CSR_SIREG6                     0x157
>
>  /* Supervisor-Level Interrupts (AIA) */
>  #define CSR_STOPEI                     0x15c
> @@ -391,9 +400,14 @@
>  #define CSR_HVIPRIO1                   0x646
>  #define CSR_HVIPRIO2                   0x647
>
> -/* VS-Level Window to Indirectly Accessed Registers (H-extension with AIA) */
> +/* Virtual Supervisor Indirect Alias */
>  #define CSR_VSISELECT                  0x250
>  #define CSR_VSIREG                     0x251
> +#define CSR_VSIREG2                    0x252
> +#define CSR_VSIREG3                    0x253
> +#define CSR_VSIREG4                    0x255
> +#define CSR_VSIREG5                    0x256
> +#define CSR_VSIREG6                    0x257
>
>  /* VS-Level Interrupts (H-extension with AIA) */
>  #define CSR_VSTOPEI                    0x25c
> @@ -694,9 +708,14 @@
>  #define CSR_DSCRATCH0                  0x7b2
>  #define CSR_DSCRATCH1                  0x7b3
>
> -/* Machine-Level Window to Indirectly Accessed Registers (AIA) */
> +/* Machine Indirect Register Alias */
>  #define CSR_MISELECT                   0x350
>  #define CSR_MIREG                      0x351
> +#define CSR_MIREG2                     0x352
> +#define CSR_MIREG3                     0x353
> +#define CSR_MIREG4                     0x355
> +#define CSR_MIREG5                     0x356
> +#define CSR_MIREG6                     0x357
>
>  /* Machine-Level Interrupts (AIA) */
>  #define CSR_MTOPEI                     0x35c
> diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h
> index 10dc3df5d2fc..cc78eec6f65a 100644
> --- a/include/sbi/sbi_hart.h
> +++ b/include/sbi/sbi_hart.h
> @@ -55,6 +55,14 @@ enum sbi_hart_extensions {
>         SBI_HART_EXT_SVPBMT,
>         /** Hart has debug trigger extension */
>         SBI_HART_EXT_SDTRIG,
> +       /** Hart has Smcsrind extension */
> +       SBI_HART_EXT_SMCSRIND,
> +       /** Hart has Smcdeleg extension */
> +       SBI_HART_EXT_SMCDELEG,
> +       /** Hart has Sscsrind extension */
> +       SBI_HART_EXT_SSCSRIND,
> +       /** Hart has Ssccfg extension */
> +       SBI_HART_EXT_SSCCFG,
>
>         /** Maximum index of Hart extension */
>         SBI_HART_EXT_MAX,
> diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
> index a0ab0c640035..3d1369441c05 100644
> --- a/lib/sbi/sbi_hart.c
> +++ b/lib/sbi/sbi_hart.c
> @@ -95,11 +95,16 @@ static void mstatus_init(struct sbi_scratch *scratch)
>                 mstateen_val |= SMSTATEEN0_HSENVCFG;
>
>                 if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SMAIA))
> -                       mstateen_val |= (SMSTATEEN0_AIA | SMSTATEEN0_SVSLCT |
> -                                       SMSTATEEN0_IMSIC);
> +                       mstateen_val |= (SMSTATEEN0_AIA | SMSTATEEN0_IMSIC);
>                 else
> -                       mstateen_val &= ~(SMSTATEEN0_AIA | SMSTATEEN0_SVSLCT |
> -                                       SMSTATEEN0_IMSIC);
> +                       mstateen_val &= ~(SMSTATEEN0_AIA | SMSTATEEN0_IMSIC);
> +
> +               if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SMAIA) ||
> +                   sbi_hart_has_extension(scratch, SBI_HART_EXT_SMCSRIND))
> +                       mstateen_val |= (SMSTATEEN0_SVSLCT);
> +               else
> +                       mstateen_val &= ~(SMSTATEEN0_SVSLCT);
> +
>                 csr_write(CSR_MSTATEEN0, mstateen_val);
>  #if __riscv_xlen == 32
>                 csr_write(CSR_MSTATEEN0H, mstateen_val >> 32);
> @@ -129,6 +134,7 @@ static void mstatus_init(struct sbi_scratch *scratch)
>                 __set_menvcfg_ext(SBI_HART_EXT_SVPBMT, ENVCFG_PBMTE)
>  #endif
>                 __set_menvcfg_ext(SBI_HART_EXT_SSTC, ENVCFG_STCE)
> +               __set_menvcfg_ext(SBI_HART_EXT_SMCDELEG, ENVCFG_CDE);
>
>  #undef __set_menvcfg_ext
>
> @@ -658,6 +664,8 @@ const struct sbi_hart_ext_data sbi_hart_ext[] = {
>         __SBI_HART_EXT_DATA(zicbom, SBI_HART_EXT_ZICBOM),
>         __SBI_HART_EXT_DATA(svpbmt, SBI_HART_EXT_SVPBMT),
>         __SBI_HART_EXT_DATA(sdtrig, SBI_HART_EXT_SDTRIG),
> +       __SBI_HART_EXT_DATA(smcsrind, SBI_HART_EXT_SMCSRIND),
> +       __SBI_HART_EXT_DATA(smcdeleg, SBI_HART_EXT_SMCDELEG),
>  };
>
>  /**
> --
> 2.34.1
>