[Skiboot] [PATCH Skiboot v1.2 2/3] Self save API integration

Oliver O'Halloran oohall at gmail.com
Fri Oct 11 12:14:03 AEDT 2019


On Thu, Oct 10, 2019 at 11:10 PM Pratik Rajesh Sampat
<psampat at linux.ibm.com> wrote:
>
> The commit makes the self save API available outside the firmware by defining
> an OPAL wrapper.
> This wrapper has a similar interface to that of self restore and expects the
> cpu pir, SPR number, minus the value of that SPR to be passed in its
> paramters and returns OPAL_SUCCESS on success.

Any need OPAL calls need to be documented in doc/opal-api/

>
> Signed-off-by: Pratik Rajesh Sampat <psampat at linux.ibm.com>
> ---
>  hw/slw.c              | 88 +++++++++++++++++++++++++++++++++++++++++++
>  include/opal-api.h    |  3 +-
>  include/p9_stop_api.H | 16 ++++++++
>  include/skiboot.h     |  3 ++
>  libpore/p9_stop_api.C |  2 +-
>  5 files changed, 110 insertions(+), 2 deletions(-)
>
> diff --git a/hw/slw.c b/hw/slw.c
> index bb88f0f1..b79aaab3 100644
> --- a/hw/slw.c
> +++ b/hw/slw.c
> @@ -36,6 +36,42 @@ static bool slw_current_le = false;
>  enum wakeup_engine_states wakeup_engine_state = WAKEUP_ENGINE_NOT_PRESENT;
>  bool has_deep_states = false;
>
> +/**
> + * The struct and SPR list is partially consistent with libpore/p9_stop_api.c
> + */
> +/**
> + * @brief summarizes attributes associated with a SPR register.
> + */
> +typedef struct
> +{
> +    uint32_t iv_sprId;
> +    bool     iv_isThreadScope;
> +    uint32_t iv_saveMaskPos;
> +
> +} StopSprReg_t;
> +
> +/**
> + * @brief a true in the table below means register is of scope thread
> + * whereas a false meanse register is of scope core.
> + * The number is the bit position on a uint32_t mask
> + */
> +
> +static const StopSprReg_t g_sprRegister[] =
> +{
> +       { P9_STOP_SPR_DAWR,      true,  1   },
> +       { P9_STOP_SPR_HSPRG0,    true,  3   },
> +       { P9_STOP_SPR_LDBAR,     true,  4,  },
> +       { P9_STOP_SPR_LPCR,      true,  5   },
> +       { P9_STOP_SPR_PSSCR,     true,  6   },
> +       { P9_STOP_SPR_MSR,       true,  7   },
> +       { P9_STOP_SPR_HRMOR,     false, 255 },
> +       { P9_STOP_SPR_HID,       false, 21  },
> +       { P9_STOP_SPR_HMEER,     false, 22  },
> +       { P9_STOP_SPR_PMCR,      false, 23  },
> +};
> +
> +static const uint32_t MAX_SPR_SUPPORTED        = ARRAY_SIZE(g_sprRegister);
> +
>  DEFINE_LOG_ENTRY(OPAL_RC_SLW_INIT, OPAL_PLATFORM_ERR_EVT, OPAL_SLW,
>                  OPAL_PLATFORM_FIRMWARE, OPAL_PREDICTIVE_ERR_GENERAL,
>                  OPAL_NA);
> @@ -1452,6 +1488,58 @@ int64_t opal_slw_set_reg(uint64_t cpu_pir, uint64_t sprn, uint64_t val)
>
>  opal_call(OPAL_SLW_SET_REG, opal_slw_set_reg, 3);
>
> +int64_t opal_slw_self_save_reg(uint64_t cpu_pir, uint64_t sprn)
> +{
> +       struct cpu_thread * c = find_cpu_by_pir(cpu_pir);
> +       struct proc_chip * chip;
> +       int rc;
> +       int index;
> +       uint32_t save_reg_vector = 0;
> +
> +       if (!c) {
> +               prerror("SLW: Unknown thread with pir %x\n", (u32) cpu_pir);

If you're going to print errors here then print them at PR_DEBUG or
higher. This function gets called once for every PIR in the system so
we'll get a few hundred lines printed to the console on every boot.
The existing SLW prints are spammy enough as-is...

> +               return OPAL_PARAMETER;
> +       }
> +
> +       chip = get_chip(c->chip_id);
> +       if (!chip) {
> +               prerror("SLW: Unknown chip for thread with pir %x\n",
> +                       (u32) cpu_pir);
> +               return OPAL_PARAMETER;
> +       }

> +       if (proc_gen == proc_gen_p9 && has_deep_states) {

use an early-exit rather than stacking indentation levels.

> +               if (wakeup_engine_state != WAKEUP_ENGINE_PRESENT) {
> +                       log_simple_error(&e_info(OPAL_RC_SLW_REG),
> +                               "SLW: wakeup_engine in bad state=%d chip=%x\n",
> +                               wakeup_engine_state, chip->id);
> +                       return OPAL_INTERNAL_ERROR;
> +               }
> +               for (index = 0; index < MAX_SPR_SUPPORTED; ++index) {
> +                       if (sprn == (CpuReg_t) g_sprRegister[index].iv_sprId) {
> +                               save_reg_vector = PPC_BIT32(
> +                                       g_sprRegister[index].iv_saveMaskPos);
> +                               break;
> +                       }
> +               }
> +               if (save_reg_vector == 0)
> +                       return OPAL_INTERNAL_ERROR;
> +               rc = p9_stop_save_cpureg_control((void *) chip->homer_base,
> +                                                cpu_pir, save_reg_vector);
> +
> +               if (rc) {
> +                       log_simple_error(&e_info(OPAL_RC_SLW_REG),
> +                               "SLW: Failed to save vector %x for CPU %x\n",
> +                               save_reg_vector, c->pir);
> +                       return OPAL_INTERNAL_ERROR;
> +               }
> +               return OPAL_SUCCESS;
> +       }
> +       prerror("SLW: Does not support deep states\n");
> +       return OPAL_UNSUPPORTED;
> +}
> +
> +opal_call(OPAL_SLW_SELF_SAVE_REG, opal_slw_self_save_reg, 2);
don't put a newline between the function and opal_call()

> +
>  void slw_init(void)
>  {
>         struct proc_chip *chip;
> diff --git a/include/opal-api.h b/include/opal-api.h
> index 782666dd..53ce23e0 100644
> --- a/include/opal-api.h
> +++ b/include/opal-api.h
> @@ -219,7 +219,8 @@
>  #define OPAL_XIVE_GET_VP_STATE                 170 /* Get NVT state */
>  #define OPAL_NPU_MEM_ALLOC                     171
>  #define OPAL_NPU_MEM_RELEASE                   172
> -#define OPAL_LAST                              172
> +#define OPAL_SLW_SELF_SAVE_REG                 173
> +#define OPAL_LAST                              173

This needs to be updated since the MPIPL calls are using these numbers.

>  #define QUIESCE_HOLD                   1 /* Spin all calls at entry */
>  #define QUIESCE_REJECT                 2 /* Fail all calls with OPAL_BUSY */
> diff --git a/include/p9_stop_api.H b/include/p9_stop_api.H
> index 79abd000..e9962c37 100644
> --- a/include/p9_stop_api.H
> +++ b/include/p9_stop_api.H
> @@ -34,6 +34,8 @@
>  ///
>  /// @file   p9_stop_api.H
>  /// @brief  describes STOP API which  create/manipulate STOP image.
> +///         This header need not be consistent, however is a subset of the
> +///         libpore/p9_stop_api.H counterpart
>  ///
>  // *HWP HW Owner    :  Greg Still <stillgs at us.ibm.com>
>  // *HWP FW Owner    :  Prem Shanker Jha <premjha2 at in.ibm.com>
> @@ -155,6 +157,20 @@ StopReturnCode_t p9_stop_save_scom( void* const   i_pImage,
>                                      const ScomOperation_t i_operation,
>                                      const ScomSection_t i_section );
>
> +/**
> + * @brief       Facilitates self save and restore of a list of SPRs of a thread.
> + * @param[in]   i_pImage        points to the start of HOMER image of P9 chip.
> + * @param[in]   i_pir           PIR associated with thread
> + * @param[in]   i_saveRegVector bit vector representing SPRs that needs to be restored.
> + * @return      STOP_SAVE_SUCCESS if API succeeds, error code otherwise.
> + * @note        SPR save vector is a bit vector. For each SPR supported,
> + *              there is an associated bit position in the bit vector.Refer
> + *              to definition of SprBitPositionList_t to determine bit position
> + *              associated with a particular SPR.
> + */
> +StopReturnCode_t
> +p9_stop_save_cpureg_control( void* i_pImage, const uint64_t i_pir,
> +                             const uint32_t  i_saveRegVector );
>  #ifdef __cplusplus
>  } // extern "C"
>  };  // namespace stopImageSection ends
> diff --git a/include/skiboot.h b/include/skiboot.h
> index 6cac1cfd..1aa8bf7c 100644
> --- a/include/skiboot.h
> +++ b/include/skiboot.h
> @@ -299,6 +299,9 @@ extern void xive_late_init(void);
>  /* SLW reinit function for switching core settings */
>  extern int64_t slw_reinit(uint64_t flags);
>
> +/* Self save SPR before entering the stop state */
> +extern int64_t opal_slw_self_save_reg(uint64_t cpu_pir, uint64_t sprn);
> +
>  /* Patch SPR in SLW image */
>  extern int64_t opal_slw_set_reg(uint64_t cpu_pir, uint64_t sprn, uint64_t val);
>
> diff --git a/libpore/p9_stop_api.C b/libpore/p9_stop_api.C
> index f41086b4..d231d1eb 100644
> --- a/libpore/p9_stop_api.C
> +++ b/libpore/p9_stop_api.C
> @@ -1401,7 +1401,7 @@ STATIC StopReturnCode_t updateSelfSaveEntry( uint32_t* i_pSaveReg, uint16_t i_sp
>
>  //-----------------------------------------------------------------------------
>
> -StopReturnCode_t p9_stop_save_cpureg_control(  void* i_pImage,
> +StopReturnCode_t p9_stop_save_cpureg_control(  void* const i_pImage,
>          const uint64_t i_pir,
>          const uint32_t i_saveRegVector )
>  {
> --
> 2.21.0
>


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