[PATCH] lib: utils: Remove CSRs that set/clear an IMSIC interrupt file bits

[Atish Patra]

On Thu, Jun 16, 2022 at 4:59 AM Anup Patel <apatel at ventanamicro.com> wrote:
>
> Based on architecture review committee feedback, the [m|s|vs]seteienum,
> [m|s|vs]clreienum, [m|s|vs]seteipnum, and [m|s|vs]clreipnum CSRs are
> removed in the latest AIA draft v0.3.0 specification.
> (Refer, https://github.com/riscv/riscv-aia/releases/tag/0.3.0-draft.31)
>
> These CSRs were mostly for software convenience and software can always
> use [m|s|vs]iselect and [m|s|vs]ireg CSRs to update the IMSIC interrupt
> file bits.
>
> We update the IMSIC programming as-per above to match the latest AIA
> draft specification.
>
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> ---
>  include/sbi/riscv_encoding.h | 24 +++--------------
>  lib/utils/irqchip/imsic.c    | 51 +++++++++++++++++++++++++++++++-----
>  2 files changed, 48 insertions(+), 27 deletions(-)
>
> diff --git a/include/sbi/riscv_encoding.h b/include/sbi/riscv_encoding.h
> index a164768..68b4a7f 100644
> --- a/include/sbi/riscv_encoding.h
> +++ b/include/sbi/riscv_encoding.h
> @@ -336,14 +336,8 @@
>  #define CSR_SIREG                      0x151
>
>  /* Supervisor-Level Interrupts (AIA) */
> -#define CSR_STOPI                      0xdb0
> -
> -/* Supervisor-Level IMSIC Interface (AIA) */
> -#define CSR_SSETEIPNUM                 0x158
> -#define CSR_SCLREIPNUM                 0x159
> -#define CSR_SSETEIENUM                 0x15a
> -#define CSR_SCLREIENUM                 0x15b
>  #define CSR_STOPEI                     0x15c
> +#define CSR_STOPI                      0xdb0
>
>  /* Supervisor-Level High-Half CSRs (AIA) */
>  #define CSR_SIEH                       0x114
> @@ -405,14 +399,8 @@
>  #define CSR_VSIREG                     0x251
>
>  /* VS-Level Interrupts (H-extension with AIA) */
> -#define CSR_VSTOPI                     0xeb0
> -
> -/* VS-Level IMSIC Interface (H-extension with AIA) */
> -#define CSR_VSSETEIPNUM                0x258
> -#define CSR_VSCLREIPNUM                0x259
> -#define CSR_VSSETEIENUM                0x25a
> -#define CSR_VSCLREIENUM                0x25b
>  #define CSR_VSTOPEI                    0x25c
> +#define CSR_VSTOPI                     0xeb0
>
>  /* Hypervisor and VS-Level High-Half CSRs (H-extension with AIA) */
>  #define CSR_HIDELEGH                   0x613
> @@ -693,14 +681,8 @@
>  #define CSR_MIREG                      0x351
>
>  /* Machine-Level Interrupts (AIA) */
> -#define CSR_MTOPI                      0xfb0
> -
> -/* Machine-Level IMSIC Interface (AIA) */
> -#define CSR_MSETEIPNUM                 0x358
> -#define CSR_MCLREIPNUM                 0x359
> -#define CSR_MSETEIENUM                 0x35a
> -#define CSR_MCLREIENUM                 0x35b
>  #define CSR_MTOPEI                     0x35c
> +#define CSR_MTOPI                      0xfb0
>
>  /* Virtual Interrupts for Supervisor Level (AIA) */
>  #define CSR_MVIEN                      0x308
> diff --git a/lib/utils/irqchip/imsic.c b/lib/utils/irqchip/imsic.c
> index b29a1e9..98f2cb6 100644
> --- a/lib/utils/irqchip/imsic.c
> +++ b/lib/utils/irqchip/imsic.c
> @@ -38,10 +38,14 @@
>
>  #define IMSIC_EIP63                    0xbf
>
> +#define IMSIC_EIPx_BITS                        32
> +
>  #define IMSIC_EIE0                     0xc0
>
>  #define IMSIC_EIE63                    0xff
>
> +#define IMSIC_EIEx_BITS                        32
> +
>  #define IMSIC_DISABLE_EIDELIVERY       0
>  #define IMSIC_ENABLE_EIDELIVERY                1
>  #define IMSIC_DISABLE_EITHRESHOLD      1
> @@ -63,6 +67,18 @@ do { \
>         __v; \
>  })
>
> +#define imsic_csr_set(__c, __v)                \
> +do { \
> +       csr_write(CSR_MISELECT, __c); \
> +       csr_set(CSR_MIREG, __v); \
> +} while (0)
> +
> +#define imsic_csr_clear(__c, __v)      \
> +do { \
> +       csr_write(CSR_MISELECT, __c); \
> +       csr_clear(CSR_MIREG, __v); \
> +} while (0)
> +
>  static struct imsic_data *imsic_hartid2data[SBI_HARTMASK_MAX_BITS];
>  static int imsic_hartid2file[SBI_HARTMASK_MAX_BITS];
>
> @@ -140,6 +156,31 @@ static struct sbi_ipi_device imsic_ipi_device = {
>         .ipi_send       = imsic_ipi_send
>  };
>
> +static void imsic_local_eix_update(unsigned long base_id,
> +                                  unsigned long num_id, bool pend, bool val)
> +{
> +       unsigned long i, isel, ireg;
> +       unsigned long id = base_id, last_id = base_id + num_id;
> +
> +       while (id < last_id) {
> +               isel = id / __riscv_xlen;
> +               isel *= __riscv_xlen / IMSIC_EIPx_BITS;
> +               isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0;
> +
> +               ireg = 0;
> +               for (i = id & (__riscv_xlen - 1);
> +                    (id < last_id) && (i < __riscv_xlen); i++) {
> +                       ireg |= BIT(i);
> +                       id++;
> +               }
> +
> +               if (val)
> +                       imsic_csr_set(isel, ireg);
> +               else
> +                       imsic_csr_clear(isel, ireg);
> +       }
> +}
> +
>  void imsic_local_irqchip_init(void)
>  {
>         /*
> @@ -158,12 +199,11 @@ void imsic_local_irqchip_init(void)
>         imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY);
>
>         /* Enable IPI */
> -       csr_write(CSR_MSETEIENUM, IMSIC_IPI_ID);
> +       imsic_local_eix_update(IMSIC_IPI_ID, 1, false, true);
>  }
>
>  int imsic_warm_irqchip_init(void)
>  {
> -       unsigned long i;
>         struct imsic_data *imsic = imsic_hartid2data[current_hartid()];
>
>         /* Sanity checks */
> @@ -171,11 +211,10 @@ int imsic_warm_irqchip_init(void)
>                 return SBI_EINVAL;
>
>         /* Disable all interrupts */
> -       for (i = 1; i <= imsic->num_ids; i++)
> -               csr_write(CSR_MCLREIENUM, i);
> +       imsic_local_eix_update(1, imsic->num_ids, false, false);
>
> -       /* Clear IPI */
> -       csr_write(CSR_MCLREIPNUM, IMSIC_IPI_ID);
> +       /* Clear IPI pending */
> +       imsic_local_eix_update(IMSIC_IPI_ID, 1, true, false);
>
>         /* Local IMSIC initialization */
>         imsic_local_irqchip_init();
> --
> 2.34.1
>

Looks good to me.

Reviewed-by: Atish Patra <atishp at rivosinc.com>


-- 
Regards,
Atish