[RFC PATCH 07/11] lib: sbi: Add system suspend skeleton

Anup Patel anup at brainfault.org
Mon Jan 16 19:46:25 PST 2023


On Fri, Jan 6, 2023 at 4:52 PM Andrew Jones <ajones at ventanamicro.com> wrote:
>
> Add the SUSP extension probe and ecall support, but for now the
> system suspend function is just a stub.
>
> Signed-off-by: Andrew Jones <ajones at ventanamicro.com>

Looks good to me.

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

Regards,
Anup

> ---
>  include/sbi/sbi_ecall_interface.h |  8 ++++++
>  include/sbi/sbi_system.h          | 17 +++++++++++
>  lib/sbi/Kconfig                   |  4 +++
>  lib/sbi/objects.mk                |  3 ++
>  lib/sbi/sbi_ecall_susp.c          | 48 +++++++++++++++++++++++++++++++
>  lib/sbi/sbi_system.c              | 26 +++++++++++++++++
>  6 files changed, 106 insertions(+)
>  create mode 100644 lib/sbi/sbi_ecall_susp.c
>
> diff --git a/include/sbi/sbi_ecall_interface.h b/include/sbi/sbi_ecall_interface.h
> index a3f2bf4bdf69..98a426a74ec4 100644
> --- a/include/sbi/sbi_ecall_interface.h
> +++ b/include/sbi/sbi_ecall_interface.h
> @@ -29,6 +29,7 @@
>  #define SBI_EXT_HSM                            0x48534D
>  #define SBI_EXT_SRST                           0x53525354
>  #define SBI_EXT_PMU                            0x504D55
> +#define SBI_EXT_SUSP                           0x53555350
>
>  /* SBI function IDs for BASE extension*/
>  #define SBI_EXT_BASE_GET_SPEC_VERSION          0x0
> @@ -230,6 +231,13 @@ enum sbi_pmu_ctr_type {
>  /* Flags defined for counter stop function */
>  #define SBI_PMU_STOP_FLAG_RESET (1 << 0)
>
> +/* SBI function IDs for SUSP extension */
> +#define SBI_EXT_SUSP_SUSPEND                   0x0
> +
> +#define SBI_SUSP_SLEEP_TYPE_SUSPEND            0x0
> +#define SBI_SUSP_SLEEP_TYPE_LAST               SBI_SUSP_SLEEP_TYPE_SUSPEND
> +#define SBI_SUSP_PLATFORM_SLEEP_START          0x80000000
> +
>  /* SBI base specification related macros */
>  #define SBI_SPEC_VERSION_MAJOR_OFFSET          24
>  #define SBI_SPEC_VERSION_MAJOR_MASK            0x7f
> diff --git a/include/sbi/sbi_system.h b/include/sbi/sbi_system.h
> index 84c281383d8c..65ea3d36d6cf 100644
> --- a/include/sbi/sbi_system.h
> +++ b/include/sbi/sbi_system.h
> @@ -43,4 +43,21 @@ bool sbi_system_reset_supported(u32 reset_type, u32 reset_reason);
>
>  void __noreturn sbi_system_reset(u32 reset_type, u32 reset_reason);
>
> +/** System suspend device */
> +struct sbi_system_suspend_device {
> +       /** Name of the system suspend device */
> +       char name[32];
> +
> +       /* Check whether sleep type is supported by the device */
> +       int (*system_suspend_check)(u32 sleep_type);
> +
> +       /** Suspend the system */
> +       int (*system_suspend)(u32 sleep_type);
> +};
> +
> +const struct sbi_system_suspend_device *sbi_system_suspend_get_device(void);
> +void sbi_system_suspend_set_device(struct sbi_system_suspend_device *dev);
> +bool sbi_system_suspend_supported(u32 sleep_type);
> +int sbi_system_suspend(u32 sleep_type, ulong resume_addr, ulong opaque);
> +
>  #endif
> diff --git a/lib/sbi/Kconfig b/lib/sbi/Kconfig
> index df74bba38540..7e139017fec7 100644
> --- a/lib/sbi/Kconfig
> +++ b/lib/sbi/Kconfig
> @@ -22,6 +22,10 @@ config SBI_ECALL_SRST
>         bool "System Reset extension"
>         default y
>
> +config SBI_ECALL_SUSP
> +       bool "System Suspend extension"
> +       default y
> +
>  config SBI_ECALL_PMU
>         bool "Performance Monitoring Unit extension"
>         default y
> diff --git a/lib/sbi/objects.mk b/lib/sbi/objects.mk
> index c774ebbcd142..c4f3d0991aa2 100644
> --- a/lib/sbi/objects.mk
> +++ b/lib/sbi/objects.mk
> @@ -34,6 +34,9 @@ libsbi-objs-$(CONFIG_SBI_ECALL_HSM) += sbi_ecall_hsm.o
>  carray-sbi_ecall_exts-$(CONFIG_SBI_ECALL_SRST) += ecall_srst
>  libsbi-objs-$(CONFIG_SBI_ECALL_SRST) += sbi_ecall_srst.o
>
> +carray-sbi_ecall_exts-$(CONFIG_SBI_ECALL_SUSP) += ecall_susp
> +libsbi-objs-$(CONFIG_SBI_ECALL_SUSP) += sbi_ecall_susp.o
> +
>  carray-sbi_ecall_exts-$(CONFIG_SBI_ECALL_PMU) += ecall_pmu
>  libsbi-objs-$(CONFIG_SBI_ECALL_PMU) += sbi_ecall_pmu.o
>
> diff --git a/lib/sbi/sbi_ecall_susp.c b/lib/sbi/sbi_ecall_susp.c
> new file mode 100644
> index 000000000000..f20126c49a60
> --- /dev/null
> +++ b/lib/sbi/sbi_ecall_susp.c
> @@ -0,0 +1,48 @@
> +// SPDX-License-Identifier: BSD-2-Clause
> +#include <sbi/sbi_ecall.h>
> +#include <sbi/sbi_ecall_interface.h>
> +#include <sbi/sbi_error.h>
> +#include <sbi/sbi_trap.h>
> +#include <sbi/sbi_system.h>
> +
> +static int sbi_ecall_susp_handler(unsigned long extid, unsigned long funcid,
> +                                 const struct sbi_trap_regs *regs,
> +                                 unsigned long *out_val,
> +                                 struct sbi_trap_info *out_trap)
> +{
> +       int ret = SBI_ENOTSUPP;
> +
> +       if (funcid == SBI_EXT_SUSP_SUSPEND)
> +               ret = sbi_system_suspend(regs->a0, regs->a1, regs->a2);
> +
> +       if (ret >= 0) {
> +               *out_val = ret;
> +               ret = 0;
> +       }
> +
> +       return ret;
> +}
> +
> +static int sbi_ecall_susp_probe(unsigned long extid, unsigned long *out_val)
> +{
> +       u32 type, count = 0;
> +
> +       /*
> +        * At least one suspend type should be supported by the
> +        * platform for the SBI SUSP extension to be usable.
> +        */
> +       for (type = 0; type <= SBI_SUSP_SLEEP_TYPE_LAST; type++) {
> +               if (sbi_system_suspend_supported(type))
> +                       count++;
> +       }
> +
> +       *out_val = count ? 1 : 0;
> +       return 0;
> +}
> +
> +struct sbi_ecall_extension ecall_susp = {
> +       .extid_start = SBI_EXT_SUSP,
> +       .extid_end = SBI_EXT_SUSP,
> +       .handle = sbi_ecall_susp_handler,
> +       .probe = sbi_ecall_susp_probe,
> +};
> diff --git a/lib/sbi/sbi_system.c b/lib/sbi/sbi_system.c
> index f37c811d0bf3..5c123a6c9d8d 100644
> --- a/lib/sbi/sbi_system.c
> +++ b/lib/sbi/sbi_system.c
> @@ -92,3 +92,29 @@ void __noreturn sbi_system_reset(u32 reset_type, u32 reset_reason)
>         /* If platform specific reset did not work then do sbi_exit() */
>         sbi_exit(scratch);
>  }
> +
> +static const struct sbi_system_suspend_device *suspend_dev = NULL;
> +
> +const struct sbi_system_suspend_device *sbi_system_suspend_get_device(void)
> +{
> +       return suspend_dev;
> +}
> +
> +void sbi_system_suspend_set_device(struct sbi_system_suspend_device *dev)
> +{
> +       if (!dev || suspend_dev)
> +               return;
> +
> +       suspend_dev = dev;
> +}
> +
> +bool sbi_system_suspend_supported(u32 sleep_type)
> +{
> +       return suspend_dev && suspend_dev->system_suspend_check &&
> +              suspend_dev->system_suspend_check(sleep_type);
> +}
> +
> +int sbi_system_suspend(u32 sleep_type, ulong resume_addr, ulong opaque)
> +{
> +       return 0;
> +}
> --
> 2.39.0
>
>
> --
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