diff options
Diffstat (limited to 'drivers/resctrl')
| -rw-r--r-- | drivers/resctrl/mpam_devices.c | 392 | ||||
| -rw-r--r-- | drivers/resctrl/mpam_internal.h | 94 |
2 files changed, 485 insertions, 1 deletions
diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index e097e852f9c3..f1dcf9bb14f2 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -37,6 +37,383 @@ struct srcu_struct mpam_srcu; static atomic_t mpam_num_msc; /* + * An MSC is a physical container for controls and monitors, each identified by + * their RIS index. These share a base-address, interrupts and some MMIO + * registers. A vMSC is a virtual container for RIS in an MSC that control or + * monitor the same thing. Members of a vMSC are all RIS in the same MSC, but + * not all RIS in an MSC share a vMSC. + * + * Components are a group of vMSC that control or monitor the same thing but + * are from different MSC, so have different base-address, interrupts etc. + * Classes are the set components of the same type. + * + * The features of a vMSC is the union of the RIS it contains. + * The features of a Class and Component are the common subset of the vMSC + * they contain. + * + * e.g. The system cache may have bandwidth controls on multiple interfaces, + * for regulating traffic from devices independently of traffic from CPUs. + * If these are two RIS in one MSC, they will be treated as controlling + * different things, and will not share a vMSC/component/class. + * + * e.g. The L2 may have one MSC and two RIS, one for cache-controls another + * for bandwidth. These two RIS are members of the same vMSC. + * + * e.g. The set of RIS that make up the L2 are grouped as a component. These + * are sometimes termed slices. They should be configured the same, as if there + * were only one. + * + * e.g. The SoC probably has more than one L2, each attached to a distinct set + * of CPUs. All the L2 components are grouped as a class. + * + * When creating an MSC, struct mpam_msc is added to the all mpam_all_msc list, + * then linked via struct mpam_ris to a vmsc, component and class. + * The same MSC may exist under different class->component->vmsc paths, but the + * RIS index will be unique. + */ +LIST_HEAD(mpam_classes); + +/* List of all objects that can be free()d after synchronise_srcu() */ +static LLIST_HEAD(mpam_garbage); + +static inline void init_garbage(struct mpam_garbage *garbage) +{ + init_llist_node(&garbage->llist); +} + +#define add_to_garbage(x) \ +do { \ + __typeof__(x) _x = (x); \ + _x->garbage.to_free = _x; \ + llist_add(&_x->garbage.llist, &mpam_garbage); \ +} while (0) + +static void mpam_free_garbage(void) +{ + struct mpam_garbage *iter, *tmp; + struct llist_node *to_free = llist_del_all(&mpam_garbage); + + if (!to_free) + return; + + synchronize_srcu(&mpam_srcu); + + llist_for_each_entry_safe(iter, tmp, to_free, llist) { + if (iter->pdev) + devm_kfree(&iter->pdev->dev, iter->to_free); + else + kfree(iter->to_free); + } +} + +static struct mpam_class * +mpam_class_alloc(u8 level_idx, enum mpam_class_types type) +{ + struct mpam_class *class; + + lockdep_assert_held(&mpam_list_lock); + + class = kzalloc(sizeof(*class), GFP_KERNEL); + if (!class) + return ERR_PTR(-ENOMEM); + init_garbage(&class->garbage); + + INIT_LIST_HEAD_RCU(&class->components); + /* Affinity is updated when ris are added */ + class->level = level_idx; + class->type = type; + INIT_LIST_HEAD_RCU(&class->classes_list); + + list_add_rcu(&class->classes_list, &mpam_classes); + + return class; +} + +static void mpam_class_destroy(struct mpam_class *class) +{ + lockdep_assert_held(&mpam_list_lock); + + list_del_rcu(&class->classes_list); + add_to_garbage(class); +} + +static struct mpam_class * +mpam_class_find(u8 level_idx, enum mpam_class_types type) +{ + struct mpam_class *class; + + lockdep_assert_held(&mpam_list_lock); + + list_for_each_entry(class, &mpam_classes, classes_list) { + if (class->type == type && class->level == level_idx) + return class; + } + + return mpam_class_alloc(level_idx, type); +} + +static struct mpam_component * +mpam_component_alloc(struct mpam_class *class, int id) +{ + struct mpam_component *comp; + + lockdep_assert_held(&mpam_list_lock); + + comp = kzalloc(sizeof(*comp), GFP_KERNEL); + if (!comp) + return ERR_PTR(-ENOMEM); + init_garbage(&comp->garbage); + + comp->comp_id = id; + INIT_LIST_HEAD_RCU(&comp->vmsc); + /* Affinity is updated when RIS are added */ + INIT_LIST_HEAD_RCU(&comp->class_list); + comp->class = class; + + list_add_rcu(&comp->class_list, &class->components); + + return comp; +} + +static void mpam_component_destroy(struct mpam_component *comp) +{ + struct mpam_class *class = comp->class; + + lockdep_assert_held(&mpam_list_lock); + + list_del_rcu(&comp->class_list); + add_to_garbage(comp); + + if (list_empty(&class->components)) + mpam_class_destroy(class); +} + +static struct mpam_component * +mpam_component_find(struct mpam_class *class, int id) +{ + struct mpam_component *comp; + + lockdep_assert_held(&mpam_list_lock); + + list_for_each_entry(comp, &class->components, class_list) { + if (comp->comp_id == id) + return comp; + } + + return mpam_component_alloc(class, id); +} + +static struct mpam_vmsc * +mpam_vmsc_alloc(struct mpam_component *comp, struct mpam_msc *msc) +{ + struct mpam_vmsc *vmsc; + + lockdep_assert_held(&mpam_list_lock); + + vmsc = kzalloc(sizeof(*vmsc), GFP_KERNEL); + if (!vmsc) + return ERR_PTR(-ENOMEM); + init_garbage(&vmsc->garbage); + + INIT_LIST_HEAD_RCU(&vmsc->ris); + INIT_LIST_HEAD_RCU(&vmsc->comp_list); + vmsc->comp = comp; + vmsc->msc = msc; + + list_add_rcu(&vmsc->comp_list, &comp->vmsc); + + return vmsc; +} + +static void mpam_vmsc_destroy(struct mpam_vmsc *vmsc) +{ + struct mpam_component *comp = vmsc->comp; + + lockdep_assert_held(&mpam_list_lock); + + list_del_rcu(&vmsc->comp_list); + add_to_garbage(vmsc); + + if (list_empty(&comp->vmsc)) + mpam_component_destroy(comp); +} + +static struct mpam_vmsc * +mpam_vmsc_find(struct mpam_component *comp, struct mpam_msc *msc) +{ + struct mpam_vmsc *vmsc; + + lockdep_assert_held(&mpam_list_lock); + + list_for_each_entry(vmsc, &comp->vmsc, comp_list) { + if (vmsc->msc->id == msc->id) + return vmsc; + } + + return mpam_vmsc_alloc(comp, msc); +} + +/* + * The cacheinfo structures are only populated when CPUs are online. + * This helper walks the acpi tables to include offline CPUs too. + */ +int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level, + cpumask_t *affinity) +{ + return acpi_pptt_get_cpumask_from_cache_id(cache_id, affinity); +} + +/* + * cpumask_of_node() only knows about online CPUs. This can't tell us whether + * a class is represented on all possible CPUs. + */ +static void get_cpumask_from_node_id(u32 node_id, cpumask_t *affinity) +{ + int cpu; + + for_each_possible_cpu(cpu) { + if (node_id == cpu_to_node(cpu)) + cpumask_set_cpu(cpu, affinity); + } +} + +static int mpam_ris_get_affinity(struct mpam_msc *msc, cpumask_t *affinity, + enum mpam_class_types type, + struct mpam_class *class, + struct mpam_component *comp) +{ + int err; + + switch (type) { + case MPAM_CLASS_CACHE: + err = mpam_get_cpumask_from_cache_id(comp->comp_id, class->level, + affinity); + if (err) { + dev_warn_once(&msc->pdev->dev, + "Failed to determine CPU affinity\n"); + return err; + } + + if (cpumask_empty(affinity)) + dev_warn_once(&msc->pdev->dev, "no CPUs associated with cache node\n"); + + break; + case MPAM_CLASS_MEMORY: + get_cpumask_from_node_id(comp->comp_id, affinity); + /* affinity may be empty for CPU-less memory nodes */ + break; + case MPAM_CLASS_UNKNOWN: + return 0; + } + + cpumask_and(affinity, affinity, &msc->accessibility); + + return 0; +} + +static int mpam_ris_create_locked(struct mpam_msc *msc, u8 ris_idx, + enum mpam_class_types type, u8 class_id, + int component_id) +{ + int err; + struct mpam_vmsc *vmsc; + struct mpam_msc_ris *ris; + struct mpam_class *class; + struct mpam_component *comp; + struct platform_device *pdev = msc->pdev; + + lockdep_assert_held(&mpam_list_lock); + + if (ris_idx > MPAM_MSC_MAX_NUM_RIS) + return -EINVAL; + + if (test_and_set_bit(ris_idx, &msc->ris_idxs)) + return -EBUSY; + + ris = devm_kzalloc(&msc->pdev->dev, sizeof(*ris), GFP_KERNEL); + if (!ris) + return -ENOMEM; + init_garbage(&ris->garbage); + ris->garbage.pdev = pdev; + + class = mpam_class_find(class_id, type); + if (IS_ERR(class)) + return PTR_ERR(class); + + comp = mpam_component_find(class, component_id); + if (IS_ERR(comp)) { + if (list_empty(&class->components)) + mpam_class_destroy(class); + return PTR_ERR(comp); + } + + vmsc = mpam_vmsc_find(comp, msc); + if (IS_ERR(vmsc)) { + if (list_empty(&comp->vmsc)) + mpam_component_destroy(comp); + return PTR_ERR(vmsc); + } + + err = mpam_ris_get_affinity(msc, &ris->affinity, type, class, comp); + if (err) { + if (list_empty(&vmsc->ris)) + mpam_vmsc_destroy(vmsc); + return err; + } + + ris->ris_idx = ris_idx; + INIT_LIST_HEAD_RCU(&ris->msc_list); + INIT_LIST_HEAD_RCU(&ris->vmsc_list); + ris->vmsc = vmsc; + + cpumask_or(&comp->affinity, &comp->affinity, &ris->affinity); + cpumask_or(&class->affinity, &class->affinity, &ris->affinity); + list_add_rcu(&ris->vmsc_list, &vmsc->ris); + list_add_rcu(&ris->msc_list, &msc->ris); + + return 0; +} + +static void mpam_ris_destroy(struct mpam_msc_ris *ris) +{ + struct mpam_vmsc *vmsc = ris->vmsc; + struct mpam_msc *msc = vmsc->msc; + struct mpam_component *comp = vmsc->comp; + struct mpam_class *class = comp->class; + + lockdep_assert_held(&mpam_list_lock); + + /* + * It is assumed affinities don't overlap. If they do the class becomes + * unusable immediately. + */ + cpumask_andnot(&class->affinity, &class->affinity, &ris->affinity); + cpumask_andnot(&comp->affinity, &comp->affinity, &ris->affinity); + clear_bit(ris->ris_idx, &msc->ris_idxs); + list_del_rcu(&ris->msc_list); + list_del_rcu(&ris->vmsc_list); + add_to_garbage(ris); + + if (list_empty(&vmsc->ris)) + mpam_vmsc_destroy(vmsc); +} + +int mpam_ris_create(struct mpam_msc *msc, u8 ris_idx, + enum mpam_class_types type, u8 class_id, int component_id) +{ + int err; + + mutex_lock(&mpam_list_lock); + err = mpam_ris_create_locked(msc, ris_idx, type, class_id, + component_id); + mutex_unlock(&mpam_list_lock); + if (err) + mpam_free_garbage(); + + return err; +} + +/* * An MSC can control traffic from a set of CPUs, but may only be accessible * from a (hopefully wider) set of CPUs. The common reason for this is power * management. If all the CPUs in a cluster are in PSCI:CPU_SUSPEND, the @@ -56,14 +433,25 @@ static void update_msc_accessibility(struct mpam_msc *msc) acpi_pptt_get_cpus_from_container(affinity_id, &msc->accessibility); } +/* + * There are two ways of reaching a struct mpam_msc_ris. Via the + * class->component->vmsc->ris, or via the msc. + * When destroying the msc, the other side needs unlinking and cleaning up too. + */ static void mpam_msc_destroy(struct mpam_msc *msc) { struct platform_device *pdev = msc->pdev; + struct mpam_msc_ris *ris, *tmp; lockdep_assert_held(&mpam_list_lock); + list_for_each_entry_safe(ris, tmp, &msc->ris, msc_list) + mpam_ris_destroy(ris); + list_del_rcu(&msc->all_msc_list); platform_set_drvdata(pdev, NULL); + + add_to_garbage(msc); } static void mpam_msc_drv_remove(struct platform_device *pdev) @@ -74,7 +462,7 @@ static void mpam_msc_drv_remove(struct platform_device *pdev) mpam_msc_destroy(msc); mutex_unlock(&mpam_list_lock); - synchronize_srcu(&mpam_srcu); + mpam_free_garbage(); } static struct mpam_msc *do_mpam_msc_drv_probe(struct platform_device *pdev) @@ -90,6 +478,8 @@ static struct mpam_msc *do_mpam_msc_drv_probe(struct platform_device *pdev) msc = devm_kzalloc(&pdev->dev, sizeof(*msc), GFP_KERNEL); if (!msc) return ERR_PTR(-ENOMEM); + init_garbage(&msc->garbage); + msc->garbage.pdev = pdev; err = devm_mutex_init(dev, &msc->probe_lock); if (err) diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h index 540066903eca..8f7a28d2c021 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -7,11 +7,30 @@ #include <linux/arm_mpam.h> #include <linux/cpumask.h> #include <linux/io.h> +#include <linux/llist.h> #include <linux/mutex.h> +#include <linux/srcu.h> #include <linux/types.h> +#define MPAM_MSC_MAX_NUM_RIS 16 + struct platform_device; +/* + * Structures protected by SRCU may not be freed for a surprising amount of + * time (especially if perf is running). To ensure the MPAM error interrupt can + * tear down all the structures, build a list of objects that can be garbage + * collected once synchronize_srcu() has returned. + * If pdev is non-NULL, use devm_kfree(). + */ +struct mpam_garbage { + /* member of mpam_garbage */ + struct llist_node llist; + + void *to_free; + struct platform_device *pdev; +}; + struct mpam_msc { /* member of mpam_all_msc */ struct list_head all_msc_list; @@ -45,5 +64,80 @@ struct mpam_msc { void __iomem *mapped_hwpage; size_t mapped_hwpage_sz; + + struct mpam_garbage garbage; +}; + +struct mpam_class { + /* mpam_components in this class */ + struct list_head components; + + cpumask_t affinity; + + u8 level; + enum mpam_class_types type; + + /* member of mpam_classes */ + struct list_head classes_list; + + struct mpam_garbage garbage; +}; + +struct mpam_component { + u32 comp_id; + + /* mpam_vmsc in this component */ + struct list_head vmsc; + + cpumask_t affinity; + + /* member of mpam_class:components */ + struct list_head class_list; + + /* parent: */ + struct mpam_class *class; + + struct mpam_garbage garbage; +}; + +struct mpam_vmsc { + /* member of mpam_component:vmsc_list */ + struct list_head comp_list; + + /* mpam_msc_ris in this vmsc */ + struct list_head ris; + + /* All RIS in this vMSC are members of this MSC */ + struct mpam_msc *msc; + + /* parent: */ + struct mpam_component *comp; + + struct mpam_garbage garbage; +}; + +struct mpam_msc_ris { + u8 ris_idx; + + cpumask_t affinity; + + /* member of mpam_vmsc:ris */ + struct list_head vmsc_list; + + /* member of mpam_msc:ris */ + struct list_head msc_list; + + /* parent: */ + struct mpam_vmsc *vmsc; + + struct mpam_garbage garbage; }; + +/* List of all classes - protected by srcu*/ +extern struct srcu_struct mpam_srcu; +extern struct list_head mpam_classes; + +int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level, + cpumask_t *affinity); + #endif /* MPAM_INTERNAL_H */ |