Excerpts from Haren Myneni's message of February 20, 2022 6:05 am:
>
> The coprocessor capabilities struct is used to get default and
> QoS capabilities from the hypervisor during init, DLPAR event and
> migration. So instead of allocating this struct for each event,
> define global struct and reuse it which allows the migration code
> to avoid adding an error path.
>
> Also disable copy/paste feature flag if any capabilities HCALL
> is failed.
>
Reviewed-by: Nicholas Piggin <npiggin at gmail.com>
> Signed-off-by: Haren Myneni <haren at linux.ibm.com>
> Acked-by: Nathan Lynch <nathanl at linux.ibm.com>
> ---
> arch/powerpc/platforms/pseries/vas.c | 47 ++++++++++++----------------
> 1 file changed, 20 insertions(+), 27 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c
> index 591c7597db5a..3bb219f54806 100644
> --- a/arch/powerpc/platforms/pseries/vas.c
> +++ b/arch/powerpc/platforms/pseries/vas.c
> @@ -26,6 +26,7 @@
>
> static struct vas_all_caps caps_all;
> static bool copypaste_feat;
> +static struct hv_vas_cop_feat_caps hv_cop_caps;
>
> static struct vas_caps vascaps[VAS_MAX_FEAT_TYPE];
> static DEFINE_MUTEX(vas_pseries_mutex);
> @@ -724,7 +725,6 @@ static int reconfig_close_windows(struct vas_caps *vcap, int excess_creds)
> */
> int vas_reconfig_capabilties(u8 type)
> {
> - struct hv_vas_cop_feat_caps *hv_caps;
> struct vas_cop_feat_caps *caps;
> int old_nr_creds, new_nr_creds;
> struct vas_caps *vcaps;
> @@ -738,17 +738,13 @@ int vas_reconfig_capabilties(u8 type)
> vcaps = &vascaps[type];
> caps = &vcaps->caps;
>
> - hv_caps = kmalloc(sizeof(*hv_caps), GFP_KERNEL);
> - if (!hv_caps)
> - return -ENOMEM;
> -
> mutex_lock(&vas_pseries_mutex);
> rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES, vcaps->feat,
> - (u64)virt_to_phys(hv_caps));
> + (u64)virt_to_phys(&hv_cop_caps));
> if (rc)
> goto out;
>
> - new_nr_creds = be16_to_cpu(hv_caps->target_lpar_creds);
> + new_nr_creds = be16_to_cpu(hv_cop_caps.target_lpar_creds);
>
> old_nr_creds = atomic_read(&caps->nr_total_credits);
>
> @@ -780,7 +776,6 @@ int vas_reconfig_capabilties(u8 type)
>
> out:
> mutex_unlock(&vas_pseries_mutex);
> - kfree(hv_caps);
> return rc;
> }
> /*
> @@ -822,9 +817,8 @@ static struct notifier_block pseries_vas_nb = {
>
> static int __init pseries_vas_init(void)
> {
> - struct hv_vas_cop_feat_caps *hv_cop_caps;
> struct hv_vas_all_caps *hv_caps;
> - int rc;
> + int rc = 0;
>
> /*
> * Linux supports user space COPY/PASTE only with Radix
> @@ -850,38 +844,37 @@ static int __init pseries_vas_init(void)
>
> sysfs_pseries_vas_init(&caps_all);
>
> - hv_cop_caps = kmalloc(sizeof(*hv_cop_caps), GFP_KERNEL);
> - if (!hv_cop_caps) {
> - rc = -ENOMEM;
> - goto out;
> - }
> /*
> * QOS capabilities available
> */
> if (caps_all.feat_type & VAS_GZIP_QOS_FEAT_BIT) {
> rc = get_vas_capabilities(VAS_GZIP_QOS_FEAT,
> - VAS_GZIP_QOS_FEAT_TYPE, hv_cop_caps);
> + VAS_GZIP_QOS_FEAT_TYPE, &hv_cop_caps);
>
> if (rc)
> - goto out_cop;
> + goto out;
> }
> /*
> * Default capabilities available
> */
> - if (caps_all.feat_type & VAS_GZIP_DEF_FEAT_BIT) {
> + if (caps_all.feat_type & VAS_GZIP_DEF_FEAT_BIT)
> rc = get_vas_capabilities(VAS_GZIP_DEF_FEAT,
> - VAS_GZIP_DEF_FEAT_TYPE, hv_cop_caps);
> - if (rc)
> - goto out_cop;
> - }
> + VAS_GZIP_DEF_FEAT_TYPE, &hv_cop_caps);
>
> - if (copypaste_feat && firmware_has_feature(FW_FEATURE_LPAR))
> - of_reconfig_notifier_register(&pseries_vas_nb);
> + if (!rc && copypaste_feat) {
> + if (firmware_has_feature(FW_FEATURE_LPAR))
> + of_reconfig_notifier_register(&pseries_vas_nb);
>
> - pr_info("GZIP feature is available\n");
> + pr_info("GZIP feature is available\n");
> + } else {
> + /*
> + * Should not happen, but only when get default
> + * capabilities HCALL failed. So disable copy paste
> + * feature.
> + */
> + copypaste_feat = false;
> + }
>
> -out_cop:
> - kfree(hv_cop_caps);
> out:
> kfree(hv_caps);
> return rc;
> --
> 2.27.0
>
>
>