Excerpts from Haren Myneni's message of April 18, 2021 7:08 am: > > pHyp provides various VAS capabilities such as GZIP default and QoS > capabilities which are used to determine total number of credits > available in LPAR, maximum window credits, maximum LPAR credits, > whether usermode copy/paste is supported, and etc. > > So first retrieve overall vas capabilities using > H_QUERY_VAS_CAPABILITIES HCALL which tells the specific features that > are available. Then retrieve the specific capabilities by using the > feature type in H_QUERY_VAS_CAPABILITIES HCALL. > > pHyp supports only GZIP default and GZIP QoS capabilities right now. Changelog and title could use a bit of work. > > Signed-off-by: Haren Myneni <haren@xxxxxxxxxxxxx> > --- > arch/powerpc/platforms/pseries/vas.c | 130 +++++++++++++++++++++++++++ > 1 file changed, 130 insertions(+) > > diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c > index 06960151477c..35946fb02995 100644 > --- a/arch/powerpc/platforms/pseries/vas.c > +++ b/arch/powerpc/platforms/pseries/vas.c > @@ -30,6 +30,13 @@ > /* phyp allows one credit per window right now */ > #define DEF_WIN_CREDS 1 > > +static struct vas_all_capabs capabs_all; Does this name come from PAPR? If not, capabilities or caps are better for readability than capabs. > +static int copypaste_feat; Should be a bool? And what does it mean? copy-paste is a host core capability. > + > +struct vas_capabs vcapabs[VAS_MAX_FEAT_TYPE]; > + > +DEFINE_MUTEX(vas_pseries_mutex); Can these be made static if they're only used here, and export them if a future patch uses them (or add the header declaration now). > + > static int64_t hcall_return_busy_check(int64_t rc) > { > /* Check if we are stalled for some time */ > @@ -215,3 +222,126 @@ int plpar_vas_query_capabilities(const u64 hcall, u8 query_type, > return -EIO; > } > } > + > +/* > + * Get the specific capabilities based on the feature type. > + * Right now supports GZIP default and GZIP QoS capabilities. > + */ > +static int get_vas_capabilities(u8 feat, enum vas_cop_feat_type type, > + struct vas_ct_capabs_be *capab_be) > +{ > + struct vas_ct_capabs *capab; > + struct vas_capabs *vcapab; > + int rc = 0; > + > + vcapab = &vcapabs[type]; > + memset(vcapab, 0, sizeof(*vcapab)); > + INIT_LIST_HEAD(&vcapab->list); > + > + capab = &vcapab->capab; > + > + rc = plpar_vas_query_capabilities(H_QUERY_VAS_CAPABILITIES, feat, > + (u64)virt_to_phys(capab_be)); > + if (rc) > + return rc; > + > + capab->user_mode = capab_be->user_mode; > + if (!(capab->user_mode & VAS_COPY_PASTE_USER_MODE)) { > + pr_err("User space COPY/PASTE is not supported\n"); > + return -ENOTSUPP; > + } > + > + snprintf(capab->name, VAS_DESCR_LEN + 1, "%.8s", > + (char *)&capab_be->descriptor); > + capab->descriptor = be64_to_cpu(capab_be->descriptor); > + capab->win_type = capab_be->win_type; > + if (capab->win_type >= VAS_MAX_FEAT_TYPE) { > + pr_err("Unsupported window type %u\n", capab->win_type); > + return -EINVAL; > + } > + capab->max_lpar_creds = be16_to_cpu(capab_be->max_lpar_creds); > + capab->max_win_creds = be16_to_cpu(capab_be->max_win_creds); > + atomic_set(&capab->target_lpar_creds, > + be16_to_cpu(capab_be->target_lpar_creds)); > + if (feat == VAS_GZIP_DEF_FEAT) { > + capab->def_lpar_creds = be16_to_cpu(capab_be->def_lpar_creds); > + > + if (capab->max_win_creds < DEF_WIN_CREDS) { > + pr_err("Window creds(%u) > max allowed window creds(%u)\n", > + DEF_WIN_CREDS, capab->max_win_creds); > + return -EINVAL; > + } > + } > + > + copypaste_feat = 1; > + > + return 0; > +} > + > +static int __init pseries_vas_init(void) > +{ > + struct vas_ct_capabs_be *ct_capabs_be; > + struct vas_all_capabs_be *capabs_be; > + int rc; > + > + /* > + * Linux supports user space COPY/PASTE only with Radix > + */ > + if (!radix_enabled()) { > + pr_err("API is supported only with radix page tables\n"); > + return -ENOTSUPP; > + } > + > + capabs_be = kmalloc(sizeof(*capabs_be), GFP_KERNEL); > + if (!capabs_be) > + return -ENOMEM; > + /* > + * Get VAS overall capabilities by passing 0 to feature type. > + */ > + rc = plpar_vas_query_capabilities(H_QUERY_VAS_CAPABILITIES, 0, > + (u64)virt_to_phys(capabs_be)); > + if (rc) > + goto out; > + > + snprintf(capabs_all.name, VAS_DESCR_LEN, "%.7s", > + (char *)&capabs_be->descriptor); > + capabs_all.descriptor = be64_to_cpu(capabs_be->descriptor); > + capabs_all.feat_type = be64_to_cpu(capabs_be->feat_type); > + > + ct_capabs_be = kmalloc(sizeof(*ct_capabs_be), GFP_KERNEL); > + if (!ct_capabs_be) { > + rc = -ENOMEM; > + goto out; > + } > + /* > + * QOS capabilities available > + */ > + if (capabs_all.feat_type & VAS_GZIP_QOS_FEAT_BIT) { > + rc = get_vas_capabilities(VAS_GZIP_QOS_FEAT, > + VAS_GZIP_QOS_FEAT_TYPE, ct_capabs_be); > + > + if (rc) > + goto out_ct; > + } > + /* > + * Default capabilities available > + */ > + if (capabs_all.feat_type & VAS_GZIP_DEF_FEAT_BIT) { > + rc = get_vas_capabilities(VAS_GZIP_DEF_FEAT, > + VAS_GZIP_DEF_FEAT_TYPE, ct_capabs_be); > + if (rc) > + goto out_ct; > + } Using the same buffer for two hcalls? Do they fill in different parts of it? > + > + if (!copypaste_feat) > + pr_err("GZIP feature is not supported\n"); This is dead code AFAIKS, because errors will always branch to out. Thanks, Nick > + > + pr_info("GZIP feature is available\n"); > + > +out_ct: > + kfree(ct_capabs_be); > +out: > + kfree(capabs_be); > + return rc; > +} > +machine_device_initcall(pseries, pseries_vas_init); > -- > 2.18.2 > > >