From: James Morse <james.morse@arm.com> maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8T2RT Reference: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/... --------------------------- To make a decision about whether to expose an mpam class as a resctrl resource we need to know its overall supported features and properties. Once we've probed all the resources, we can walk the tree and produced overall values by merging the bitmaps. This eliminates features that are only supported by some MSC that make up a component or class. If bitmap properties are mismatched within a component we cannot support the mismatched feature. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Zeng Heng <zengheng4@huawei.com> --- drivers/platform/mpam/mpam_devices.c | 87 +++++++++++++++++++++++++++ drivers/platform/mpam/mpam_internal.h | 8 +++ 2 files changed, 95 insertions(+) diff --git a/drivers/platform/mpam/mpam_devices.c b/drivers/platform/mpam/mpam_devices.c index 7eeeb44506b1..f1574f393e1d 100644 --- a/drivers/platform/mpam/mpam_devices.c +++ b/drivers/platform/mpam/mpam_devices.c @@ -938,8 +938,95 @@ static int mpam_msc_drv_probe(struct platform_device *pdev) return err; } +/* + * If a resource doesn't match class feature/configuration, do the right thing. + * For 'num' properties we can just take the minimum. + * For properties where the mismatched unused bits would make a difference, we + * nobble the class feature, as we can't configure all the resources. + * e.g. The L3 cache is composed of two resources with 13 and 17 portion + * bitmaps respectively. + */ +static void +__resource_props_mismatch(struct mpam_msc_ris *ris, struct mpam_class *class) +{ + struct mpam_props *cprops = &class->props; + struct mpam_props *rprops = &ris->props; + + lockdep_assert_held(&mpam_list_lock); /* we modify class */ + + /* Clear missing features */ + cprops->features &= rprops->features; + + /* Clear incompatible features */ + if (cprops->cpbm_wd != rprops->cpbm_wd) + mpam_clear_feature(mpam_feat_cpor_part, &cprops->features); + if (cprops->mbw_pbm_bits != rprops->mbw_pbm_bits) + mpam_clear_feature(mpam_feat_mbw_part, &cprops->features); + + /* bwa_wd is a count of bits, fewer bits means less precision */ + if (cprops->bwa_wd != rprops->bwa_wd) + cprops->bwa_wd = min(cprops->bwa_wd, rprops->bwa_wd); + + /* For num properties, take the minimum */ + if (cprops->num_csu_mon != rprops->num_csu_mon) + cprops->num_csu_mon = min(cprops->num_csu_mon, rprops->num_csu_mon); + if (cprops->num_mbwu_mon != rprops->num_mbwu_mon) + cprops->num_mbwu_mon = min(cprops->num_mbwu_mon, rprops->num_mbwu_mon); +} + +/* + * Copy the first component's first resources's properties and features to the + * class. __resource_props_mismatch() will remove conflicts. + * It is not possible to have a class with no components, or a component with + * no resources. + */ +static void mpam_enable_init_class_features(struct mpam_class *class) +{ + struct mpam_msc_ris *ris; + struct mpam_component *comp; + + comp = list_first_entry_or_null(&class->components, + struct mpam_component, class_list); + if (WARN_ON(!comp)) + return; + + ris = list_first_entry_or_null(&comp->ris, + struct mpam_msc_ris, comp_list); + if (WARN_ON(!ris)) + return; + + class->props = ris->props; +} + +/* Merge all the common resource features into class. */ +static void mpam_enable_merge_features(void) +{ + struct mpam_msc_ris *ris; + struct mpam_class *class; + struct mpam_component *comp; + + lockdep_assert_held(&mpam_list_lock); + + list_for_each_entry(class, &mpam_classes, classes_list) { + mpam_enable_init_class_features(class); + + list_for_each_entry(comp, &class->components, class_list) { + list_for_each_entry(ris, &comp->ris, comp_list) { + __resource_props_mismatch(ris, class); + + class->nrdy_usec = max(class->nrdy_usec, + ris->msc->nrdy_usec); + } + } + } +} + static void mpam_enable_once(void) { + mutex_lock(&mpam_list_lock); + mpam_enable_merge_features(); + mutex_unlock(&mpam_list_lock); + mutex_lock(&mpam_cpuhp_state_lock); cpuhp_remove_state(mpam_cpuhp_state); mpam_cpuhp_state = 0; diff --git a/drivers/platform/mpam/mpam_internal.h b/drivers/platform/mpam/mpam_internal.h index 71e62594876d..db50f5e40d98 100644 --- a/drivers/platform/mpam/mpam_internal.h +++ b/drivers/platform/mpam/mpam_internal.h @@ -97,6 +97,12 @@ static inline void mpam_set_feature(enum mpam_device_features feat, props->features |= (1<<feat); } +static inline void mpam_clear_feature(enum mpam_device_features feat, + mpam_features_t *supported) +{ + *supported &= ~(1<<feat); +} + struct mpam_class { /* mpam_components in this class */ @@ -104,6 +110,8 @@ struct mpam_class cpumask_t affinity; + struct mpam_props props; + u32 nrdy_usec; u8 level; enum mpam_class_types type; -- 2.25.1