Re: [PATCH v04 3/5] migration/memory: Add hotplug READD_MULTIPLE

[Nathan Fontenot <nfont@linux.vnet.ibm.com>]

On 10/09/2018 03:36 PM, Michael Bringmann wrote:
> migration/memory: This patch adds a new pseries hotplug action
> for CPU and memory operations, PSERIES_HP_ELOG_ACTION_READD_MULTIPLE.
> This is a variant of the READD operation which performs the action
> upon multiple instances of the resource at one time.  The operation
> is to be triggered by device-tree analysis of updates by RTAS events
> analyzed by 'migation_store' during post-migration processing.  It
> will be used for memory updates, initially.
> 
> Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
> ---
> Changes in v04:
>   -- Move init of 'lmb->internal_flags' in init_drmem_v2_lmbs to
>      previous patch.
>   -- Pull in implementation of dlpar_memory_readd_multiple() to go
>      with operation flag.
> ---
>  arch/powerpc/include/asm/rtas.h                 |    1 +
>  arch/powerpc/platforms/pseries/hotplug-memory.c |   31 +++++++++++++++++++++++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
> index 0183e95..cc00451 100644
> --- a/arch/powerpc/include/asm/rtas.h
> +++ b/arch/powerpc/include/asm/rtas.h
> @@ -333,6 +333,7 @@ struct pseries_hp_errorlog {
>  #define PSERIES_HP_ELOG_ACTION_ADD	1
>  #define PSERIES_HP_ELOG_ACTION_REMOVE	2
>  #define PSERIES_HP_ELOG_ACTION_READD	3
> +#define PSERIES_HP_ELOG_ACTION_READD_MULTIPLE	4
> 
>  #define PSERIES_HP_ELOG_ID_DRC_NAME	1
>  #define PSERIES_HP_ELOG_ID_DRC_INDEX	2
> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
> index 9a15d39..bf2420a 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -546,6 +546,30 @@ static int dlpar_memory_readd_by_index(u32 drc_index)
>  	return rc;
>  }
> 
> +static int dlpar_memory_readd_multiple(void)
> +{
> +	struct drmem_lmb *lmb;
> +	int rc;
> +
> +	pr_info("Attempting to update multiple LMBs\n");
> +
> +	for_each_drmem_lmb(lmb) {
> +		if (drmem_lmb_update(lmb)) {
> +			rc = dlpar_remove_lmb(lmb);
> +
> +			if (!rc) {
> +				rc = dlpar_add_lmb(lmb);
> +				if (rc)
> +					dlpar_release_drc(lmb->drc_index);
> +			}

The work you're doing here is essentially the same that is done in
dlpar_memory_readd_by_index(). Perhaps pulling the commin bits of both
routines into a helper routine. This could include the success/failure
messages in dlpar_memory_readd_by_index()

-Nathan

> +
> +			drmem_remove_lmb_update(lmb);
> +		}
> +	}
> +
> +	return rc;
> +}
> +
>  static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
>  {
>  	struct drmem_lmb *lmb, *start_lmb, *end_lmb;
> @@ -646,6 +670,10 @@ static int dlpar_memory_readd_by_index(u32 drc_index)
>  {
>  	return -EOPNOTSUPP;
>  }
> +static int dlpar_memory_readd_multiple(void)
> +{
> +	return -EOPNOTSUPP;
> +}
> 
>  static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
>  {
> @@ -923,6 +951,9 @@ int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
>  		drc_index = hp_elog->_drc_u.drc_index;
>  		rc = dlpar_memory_readd_by_index(drc_index);
>  		break;
> +	case PSERIES_HP_ELOG_ACTION_READD_MULTIPLE:
> +		rc = dlpar_memory_readd_multiple();
> +		break;
>  	default:
>  		pr_err("Invalid action (%d) specified\n", hp_elog->action);
>  		rc = -EINVAL;
>