diff options
Diffstat (limited to 'drivers/resctrl/mpam_devices.c')
| -rw-r--r-- | drivers/resctrl/mpam_devices.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index ff561a08cd0d..f9ac88bf06b7 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -965,6 +965,216 @@ static struct platform_driver mpam_msc_driver = { .remove = mpam_msc_drv_remove, }; +/* Any of these features mean the BWA_WD field is valid. */ +static bool mpam_has_bwa_wd_feature(struct mpam_props *props) +{ + if (mpam_has_feature(mpam_feat_mbw_min, props)) + return true; + if (mpam_has_feature(mpam_feat_mbw_max, props)) + return true; + return false; +} + +#define MISMATCHED_HELPER(parent, child, helper, field, alias) \ + helper(parent) && \ + ((helper(child) && (parent)->field != (child)->field) || \ + (!helper(child) && !(alias))) + +#define MISMATCHED_FEAT(parent, child, feat, field, alias) \ + mpam_has_feature((feat), (parent)) && \ + ((mpam_has_feature((feat), (child)) && (parent)->field != (child)->field) || \ + (!mpam_has_feature((feat), (child)) && !(alias))) + +#define CAN_MERGE_FEAT(parent, child, feat, alias) \ + (alias) && !mpam_has_feature((feat), (parent)) && \ + mpam_has_feature((feat), (child)) + +/* + * Combine two props fields. + * If this is for controls that alias the same resource, it is safe to just + * copy the values over. If two aliasing controls implement the same scheme + * a safe value must be picked. + * For non-aliasing controls, these control different resources, and the + * resulting safe value must be compatible with both. When merging values in + * the tree, all the aliasing resources must be handled first. + * On mismatch, parent is modified. + */ +static void __props_mismatch(struct mpam_props *parent, + struct mpam_props *child, bool alias) +{ + if (CAN_MERGE_FEAT(parent, child, mpam_feat_cpor_part, alias)) { + parent->cpbm_wd = child->cpbm_wd; + } else if (MISMATCHED_FEAT(parent, child, mpam_feat_cpor_part, + cpbm_wd, alias)) { + pr_debug("cleared cpor_part\n"); + mpam_clear_feature(mpam_feat_cpor_part, parent); + parent->cpbm_wd = 0; + } + + if (CAN_MERGE_FEAT(parent, child, mpam_feat_mbw_part, alias)) { + parent->mbw_pbm_bits = child->mbw_pbm_bits; + } else if (MISMATCHED_FEAT(parent, child, mpam_feat_mbw_part, + mbw_pbm_bits, alias)) { + pr_debug("cleared mbw_part\n"); + mpam_clear_feature(mpam_feat_mbw_part, parent); + parent->mbw_pbm_bits = 0; + } + + /* bwa_wd is a count of bits, fewer bits means less precision */ + if (alias && !mpam_has_bwa_wd_feature(parent) && + mpam_has_bwa_wd_feature(child)) { + parent->bwa_wd = child->bwa_wd; + } else if (MISMATCHED_HELPER(parent, child, mpam_has_bwa_wd_feature, + bwa_wd, alias)) { + pr_debug("took the min bwa_wd\n"); + parent->bwa_wd = min(parent->bwa_wd, child->bwa_wd); + } + + /* For num properties, take the minimum */ + if (CAN_MERGE_FEAT(parent, child, mpam_feat_msmon_csu, alias)) { + parent->num_csu_mon = child->num_csu_mon; + } else if (MISMATCHED_FEAT(parent, child, mpam_feat_msmon_csu, + num_csu_mon, alias)) { + pr_debug("took the min num_csu_mon\n"); + parent->num_csu_mon = min(parent->num_csu_mon, + child->num_csu_mon); + } + + if (CAN_MERGE_FEAT(parent, child, mpam_feat_msmon_mbwu, alias)) { + parent->num_mbwu_mon = child->num_mbwu_mon; + } else if (MISMATCHED_FEAT(parent, child, mpam_feat_msmon_mbwu, + num_mbwu_mon, alias)) { + pr_debug("took the min num_mbwu_mon\n"); + parent->num_mbwu_mon = min(parent->num_mbwu_mon, + child->num_mbwu_mon); + } + + if (alias) { + /* Merge features for aliased resources */ + bitmap_or(parent->features, parent->features, child->features, MPAM_FEATURE_LAST); + } else { + /* Clear missing features for non aliasing */ + bitmap_and(parent->features, parent->features, child->features, MPAM_FEATURE_LAST); + } +} + +/* + * If a vmsc doesn't match class feature/configuration, do the right thing(tm). + * 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 +__class_props_mismatch(struct mpam_class *class, struct mpam_vmsc *vmsc) +{ + struct mpam_props *cprops = &class->props; + struct mpam_props *vprops = &vmsc->props; + struct device *dev = &vmsc->msc->pdev->dev; + + lockdep_assert_held(&mpam_list_lock); /* we modify class */ + + dev_dbg(dev, "Merging features for class:0x%lx &= vmsc:0x%lx\n", + (long)cprops->features, (long)vprops->features); + + /* Take the safe value for any common features */ + __props_mismatch(cprops, vprops, false); +} + +static void +__vmsc_props_mismatch(struct mpam_vmsc *vmsc, struct mpam_msc_ris *ris) +{ + struct mpam_props *rprops = &ris->props; + struct mpam_props *vprops = &vmsc->props; + struct device *dev = &vmsc->msc->pdev->dev; + + lockdep_assert_held(&mpam_list_lock); /* we modify vmsc */ + + dev_dbg(dev, "Merging features for vmsc:0x%lx |= ris:0x%lx\n", + (long)vprops->features, (long)rprops->features); + + /* + * Merge mismatched features - Copy any features that aren't common, + * but take the safe value for any common features. + */ + __props_mismatch(vprops, rprops, true); +} + +/* + * Copy the first component's first vMSC's properties and features to the + * class. __class_props_mismatch() will remove conflicts. + * It is not possible to have a class with no components, or a component with + * no resources. The vMSC properties have already been built. + */ +static void mpam_enable_init_class_features(struct mpam_class *class) +{ + struct mpam_vmsc *vmsc; + struct mpam_component *comp; + + comp = list_first_entry(&class->components, + struct mpam_component, class_list); + vmsc = list_first_entry(&comp->vmsc, + struct mpam_vmsc, comp_list); + + class->props = vmsc->props; +} + +static void mpam_enable_merge_vmsc_features(struct mpam_component *comp) +{ + struct mpam_vmsc *vmsc; + struct mpam_msc_ris *ris; + struct mpam_class *class = comp->class; + + list_for_each_entry(vmsc, &comp->vmsc, comp_list) { + list_for_each_entry(ris, &vmsc->ris, vmsc_list) { + __vmsc_props_mismatch(vmsc, ris); + class->nrdy_usec = max(class->nrdy_usec, + vmsc->msc->nrdy_usec); + } + } +} + +static void mpam_enable_merge_class_features(struct mpam_component *comp) +{ + struct mpam_vmsc *vmsc; + struct mpam_class *class = comp->class; + + list_for_each_entry(vmsc, &comp->vmsc, comp_list) + __class_props_mismatch(class, vmsc); +} + +/* + * Merge all the common resource features into class. + * vmsc features are bitwise-or'd together by mpam_enable_merge_vmsc_features() + * as the first step so that mpam_enable_init_class_features() can initialise + * the class with a representative set of features. + * Next the mpam_enable_merge_class_features() bitwise-and's all the vmsc + * features to form the class features. + * Other features are the min/max as appropriate. + * + * To avoid walking the whole tree twice, the class->nrdy_usec property is + * updated when working with the vmsc as it is a max(), and doesn't need + * initialising first. + */ +static void mpam_enable_merge_features(struct list_head *all_classes_list) +{ + struct mpam_class *class; + struct mpam_component *comp; + + lockdep_assert_held(&mpam_list_lock); + + list_for_each_entry(class, all_classes_list, classes_list) { + list_for_each_entry(comp, &class->components, class_list) + mpam_enable_merge_vmsc_features(comp); + + mpam_enable_init_class_features(class); + + list_for_each_entry(comp, &class->components, class_list) + mpam_enable_merge_class_features(comp); + } +} + static void mpam_enable_once(void) { /* @@ -975,6 +1185,10 @@ static void mpam_enable_once(void) partid_max_published = true; spin_unlock(&partid_max_lock); + mutex_lock(&mpam_list_lock); + mpam_enable_merge_features(&mpam_classes); + mutex_unlock(&mpam_list_lock); + mpam_register_cpuhp_callbacks(mpam_cpu_online, mpam_cpu_offline, "mpam:online"); |