Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
arm_mpam: Merge supported features during mpam_enable() into mpam_class
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 produce 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.
Care has to be taken as vMSC may hold mismatched RIS.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com>
Tested-by: Gavin Shan <gshan@redhat.com>
Tested-by: Zeng Heng <zengheng4@huawei.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
authored by
James Morse
and committed by
Catalin Marinas
c10ca83a
8c90dc68
+217
+214
drivers/resctrl/mpam_devices.c
+214
drivers/resctrl/mpam_devices.c
···
965
965
.remove = mpam_msc_drv_remove,
966
966
};
967
967
968
+
/* Any of these features mean the BWA_WD field is valid. */
969
+
static bool mpam_has_bwa_wd_feature(struct mpam_props *props)
970
+
{
971
+
if (mpam_has_feature(mpam_feat_mbw_min, props))
972
+
return true;
973
+
if (mpam_has_feature(mpam_feat_mbw_max, props))
974
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return true;
975
+
return false;
976
+
}
977
+
978
+
#define MISMATCHED_HELPER(parent, child, helper, field, alias) \
979
+
helper(parent) && \
980
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((helper(child) && (parent)->field != (child)->field) || \
981
+
(!helper(child) && !(alias)))
982
+
983
+
#define MISMATCHED_FEAT(parent, child, feat, field, alias) \
984
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mpam_has_feature((feat), (parent)) && \
985
+
((mpam_has_feature((feat), (child)) && (parent)->field != (child)->field) || \
986
+
(!mpam_has_feature((feat), (child)) && !(alias)))
987
+
988
+
#define CAN_MERGE_FEAT(parent, child, feat, alias) \
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(alias) && !mpam_has_feature((feat), (parent)) && \
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mpam_has_feature((feat), (child))
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+
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/*
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* Combine two props fields.
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* If this is for controls that alias the same resource, it is safe to just
995
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* copy the values over. If two aliasing controls implement the same scheme
996
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* a safe value must be picked.
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* For non-aliasing controls, these control different resources, and the
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* resulting safe value must be compatible with both. When merging values in
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+
* the tree, all the aliasing resources must be handled first.
1000
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* On mismatch, parent is modified.
1001
+
*/
1002
+
static void __props_mismatch(struct mpam_props *parent,
1003
+
struct mpam_props *child, bool alias)
1004
+
{
1005
+
if (CAN_MERGE_FEAT(parent, child, mpam_feat_cpor_part, alias)) {
1006
+
parent->cpbm_wd = child->cpbm_wd;
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+
} else if (MISMATCHED_FEAT(parent, child, mpam_feat_cpor_part,
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+
cpbm_wd, alias)) {
1009
+
pr_debug("cleared cpor_part\n");
1010
+
mpam_clear_feature(mpam_feat_cpor_part, parent);
1011
+
parent->cpbm_wd = 0;
1012
+
}
1013
+
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if (CAN_MERGE_FEAT(parent, child, mpam_feat_mbw_part, alias)) {
1015
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parent->mbw_pbm_bits = child->mbw_pbm_bits;
1016
+
} else if (MISMATCHED_FEAT(parent, child, mpam_feat_mbw_part,
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+
mbw_pbm_bits, alias)) {
1018
+
pr_debug("cleared mbw_part\n");
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mpam_clear_feature(mpam_feat_mbw_part, parent);
1020
+
parent->mbw_pbm_bits = 0;
1021
+
}
1022
+
1023
+
/* bwa_wd is a count of bits, fewer bits means less precision */
1024
+
if (alias && !mpam_has_bwa_wd_feature(parent) &&
1025
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mpam_has_bwa_wd_feature(child)) {
1026
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parent->bwa_wd = child->bwa_wd;
1027
+
} else if (MISMATCHED_HELPER(parent, child, mpam_has_bwa_wd_feature,
1028
+
bwa_wd, alias)) {
1029
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pr_debug("took the min bwa_wd\n");
1030
+
parent->bwa_wd = min(parent->bwa_wd, child->bwa_wd);
1031
+
}
1032
+
1033
+
/* For num properties, take the minimum */
1034
+
if (CAN_MERGE_FEAT(parent, child, mpam_feat_msmon_csu, alias)) {
1035
+
parent->num_csu_mon = child->num_csu_mon;
1036
+
} else if (MISMATCHED_FEAT(parent, child, mpam_feat_msmon_csu,
1037
+
num_csu_mon, alias)) {
1038
+
pr_debug("took the min num_csu_mon\n");
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parent->num_csu_mon = min(parent->num_csu_mon,
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child->num_csu_mon);
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+
}
1042
+
1043
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if (CAN_MERGE_FEAT(parent, child, mpam_feat_msmon_mbwu, alias)) {
1044
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parent->num_mbwu_mon = child->num_mbwu_mon;
1045
+
} else if (MISMATCHED_FEAT(parent, child, mpam_feat_msmon_mbwu,
1046
+
num_mbwu_mon, alias)) {
1047
+
pr_debug("took the min num_mbwu_mon\n");
1048
+
parent->num_mbwu_mon = min(parent->num_mbwu_mon,
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+
child->num_mbwu_mon);
1050
+
}
1051
+
1052
+
if (alias) {
1053
+
/* Merge features for aliased resources */
1054
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bitmap_or(parent->features, parent->features, child->features, MPAM_FEATURE_LAST);
1055
+
} else {
1056
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/* Clear missing features for non aliasing */
1057
+
bitmap_and(parent->features, parent->features, child->features, MPAM_FEATURE_LAST);
1058
+
}
1059
+
}
1060
+
1061
+
/*
1062
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* If a vmsc doesn't match class feature/configuration, do the right thing(tm).
1063
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* For 'num' properties we can just take the minimum.
1064
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* For properties where the mismatched unused bits would make a difference, we
1065
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* nobble the class feature, as we can't configure all the resources.
1066
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* e.g. The L3 cache is composed of two resources with 13 and 17 portion
1067
+
* bitmaps respectively.
1068
+
*/
1069
+
static void
1070
+
__class_props_mismatch(struct mpam_class *class, struct mpam_vmsc *vmsc)
1071
+
{
1072
+
struct mpam_props *cprops = &class->props;
1073
+
struct mpam_props *vprops = &vmsc->props;
1074
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struct device *dev = &vmsc->msc->pdev->dev;
1075
+
1076
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lockdep_assert_held(&mpam_list_lock); /* we modify class */
1077
+
1078
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dev_dbg(dev, "Merging features for class:0x%lx &= vmsc:0x%lx\n",
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(long)cprops->features, (long)vprops->features);
1080
+
1081
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/* Take the safe value for any common features */
1082
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__props_mismatch(cprops, vprops, false);
1083
+
}
1084
+
1085
+
static void
1086
+
__vmsc_props_mismatch(struct mpam_vmsc *vmsc, struct mpam_msc_ris *ris)
1087
+
{
1088
+
struct mpam_props *rprops = &ris->props;
1089
+
struct mpam_props *vprops = &vmsc->props;
1090
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struct device *dev = &vmsc->msc->pdev->dev;
1091
+
1092
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lockdep_assert_held(&mpam_list_lock); /* we modify vmsc */
1093
+
1094
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dev_dbg(dev, "Merging features for vmsc:0x%lx |= ris:0x%lx\n",
1095
+
(long)vprops->features, (long)rprops->features);
1096
+
1097
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/*
1098
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* Merge mismatched features - Copy any features that aren't common,
1099
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* but take the safe value for any common features.
1100
+
*/
1101
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__props_mismatch(vprops, rprops, true);
1102
+
}
1103
+
1104
+
/*
1105
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* Copy the first component's first vMSC's properties and features to the
1106
+
* class. __class_props_mismatch() will remove conflicts.
1107
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* It is not possible to have a class with no components, or a component with
1108
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* no resources. The vMSC properties have already been built.
1109
+
*/
1110
+
static void mpam_enable_init_class_features(struct mpam_class *class)
1111
+
{
1112
+
struct mpam_vmsc *vmsc;
1113
+
struct mpam_component *comp;
1114
+
1115
+
comp = list_first_entry(&class->components,
1116
+
struct mpam_component, class_list);
1117
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vmsc = list_first_entry(&comp->vmsc,
1118
+
struct mpam_vmsc, comp_list);
1119
+
1120
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class->props = vmsc->props;
1121
+
}
1122
+
1123
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static void mpam_enable_merge_vmsc_features(struct mpam_component *comp)
1124
+
{
1125
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struct mpam_vmsc *vmsc;
1126
+
struct mpam_msc_ris *ris;
1127
+
struct mpam_class *class = comp->class;
1128
+
1129
+
list_for_each_entry(vmsc, &comp->vmsc, comp_list) {
1130
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list_for_each_entry(ris, &vmsc->ris, vmsc_list) {
1131
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__vmsc_props_mismatch(vmsc, ris);
1132
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class->nrdy_usec = max(class->nrdy_usec,
1133
+
vmsc->msc->nrdy_usec);
1134
+
}
1135
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}
1136
+
}
1137
+
1138
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static void mpam_enable_merge_class_features(struct mpam_component *comp)
1139
+
{
1140
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struct mpam_vmsc *vmsc;
1141
+
struct mpam_class *class = comp->class;
1142
+
1143
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list_for_each_entry(vmsc, &comp->vmsc, comp_list)
1144
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__class_props_mismatch(class, vmsc);
1145
+
}
1146
+
1147
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/*
1148
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* Merge all the common resource features into class.
1149
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* vmsc features are bitwise-or'd together by mpam_enable_merge_vmsc_features()
1150
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* as the first step so that mpam_enable_init_class_features() can initialise
1151
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* the class with a representative set of features.
1152
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* Next the mpam_enable_merge_class_features() bitwise-and's all the vmsc
1153
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* features to form the class features.
1154
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* Other features are the min/max as appropriate.
1155
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*
1156
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* To avoid walking the whole tree twice, the class->nrdy_usec property is
1157
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* updated when working with the vmsc as it is a max(), and doesn't need
1158
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* initialising first.
1159
+
*/
1160
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static void mpam_enable_merge_features(struct list_head *all_classes_list)
1161
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{
1162
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struct mpam_class *class;
1163
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struct mpam_component *comp;
1164
+
1165
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lockdep_assert_held(&mpam_list_lock);
1166
+
1167
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list_for_each_entry(class, all_classes_list, classes_list) {
1168
+
list_for_each_entry(comp, &class->components, class_list)
1169
+
mpam_enable_merge_vmsc_features(comp);
1170
+
1171
+
mpam_enable_init_class_features(class);
1172
+
1173
+
list_for_each_entry(comp, &class->components, class_list)
1174
+
mpam_enable_merge_class_features(comp);
1175
+
}
1176
+
}
1177
+
968
1178
static void mpam_enable_once(void)
969
1179
{
970
1180
/*
···
1184
974
spin_lock(&partid_max_lock);
1185
975
partid_max_published = true;
1186
976
spin_unlock(&partid_max_lock);
977
+
978
+
mutex_lock(&mpam_list_lock);
979
+
mpam_enable_merge_features(&mpam_classes);
980
+
mutex_unlock(&mpam_list_lock);
1187
981
1188
982
mpam_register_cpuhp_callbacks(mpam_cpu_online, mpam_cpu_offline,
1189
983
"mpam:online");
+3
drivers/resctrl/mpam_internal.h
+3
drivers/resctrl/mpam_internal.h
···
140
140
141
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#define mpam_has_feature(_feat, x) test_bit(_feat, (x)->features)
142
142
#define mpam_set_feature(_feat, x) set_bit(_feat, (x)->features)
143
+
#define mpam_clear_feature(_feat, x) clear_bit(_feat, (x)->features)
143
144
144
145
struct mpam_class {
145
146
/* mpam_components in this class */
···
148
147
149
148
cpumask_t affinity;
150
149
150
+
struct mpam_props props;
151
+
u32 nrdy_usec;
151
152
u8 level;
152
153
enum mpam_class_types type;
153
154