Commit 09b89d2a authored by James Morse's avatar James Morse Committed by Catalin Marinas
Browse files

arm_mpam: Allow configuration to be applied and restored during cpu online 



When CPUs come online the MSC's original configuration should be restored.

Add struct mpam_config to hold the configuration. For each component, this
has a bitmap of features that have been changed from the reset values. The
mpam_config is also used on RIS reset where all bits are set to ensure all
features are reset.

Once the maximum partid is known, allocate a configuration array for each
component, and reprogram each RIS configuration from this.

CC: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Cc: Fujitsu Fujitsu <Shaopeng Tan  tan.shaopeng@fujitsu.com>
Cc: Peter Newman peternewman@google.com
Reviewed-by: default avatarGavin Shan <gshan@redhat.com>
Reviewed-by: default avatarShaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: default avatarJonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: default avatarFenghua Yu <fenghuay@nvidia.com>
Tested-by: default avatarCarl Worth <carl@os.amperecomputing.com>
Tested-by: default avatarGavin Shan <gshan@redhat.com>
Tested-by: default avatarZeng Heng <zengheng4@huawei.com>
Tested-by: default avatarShaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: default avatarHanjun Guo <guohanjun@huawei.com>
Signed-off-by: default avatarBen Horgan <ben.horgan@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 3796f75a

drivers/resctrl/mpam_devices.c

+263 −25
Original line number Diff line number Diff line
@@ -145,6 +145,16 @@ static void mpam_free_garbage(void) 
	}

}



/*

 * Once mpam is enabled, new requestors cannot further reduce the available

 * partid. Assert that the size is fixed, and new requestors will be turned

 * away.

 */

static void mpam_assert_partid_sizes_fixed(void)

{

	WARN_ON_ONCE(!partid_max_published);

}



static u32 __mpam_read_reg(struct mpam_msc *msc, u16 reg)

{

	WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &msc->accessibility));
@@ -338,12 +348,16 @@ mpam_component_alloc(struct mpam_class *class, int id) 
	return comp;

}



static void __destroy_component_cfg(struct mpam_component *comp);



static void mpam_component_destroy(struct mpam_component *comp)

{

	struct mpam_class *class = comp->class;



	lockdep_assert_held(&mpam_list_lock);



	__destroy_component_cfg(comp);



	list_del_rcu(&comp->class_list);

	add_to_garbage(comp);
@@ -819,31 +833,57 @@ static void mpam_reset_msc_bitmap(struct mpam_msc *msc, u16 reg, u16 wd) 
	__mpam_write_reg(msc, reg, bm);

}



static void mpam_reset_ris_partid(struct mpam_msc_ris *ris, u16 partid)

/* Called via IPI. Call while holding an SRCU reference */

static void mpam_reprogram_ris_partid(struct mpam_msc_ris *ris, u16 partid,

				      struct mpam_config *cfg)

{

	struct mpam_msc *msc = ris->vmsc->msc;

	struct mpam_props *rprops = &ris->props;



	WARN_ON_ONCE(!srcu_read_lock_held((&mpam_srcu)));



	mutex_lock(&msc->part_sel_lock);

	__mpam_part_sel(ris->ris_idx, partid, msc);



	if (mpam_has_feature(mpam_feat_cpor_part, rprops))

	if (mpam_has_feature(mpam_feat_cpor_part, rprops) &&

	    mpam_has_feature(mpam_feat_cpor_part, cfg)) {

		if (cfg->reset_cpbm)

			mpam_reset_msc_bitmap(msc, MPAMCFG_CPBM, rprops->cpbm_wd);

		else

			mpam_write_partsel_reg(msc, CPBM, cfg->cpbm);

	}



	if (mpam_has_feature(mpam_feat_mbw_part, rprops))

	if (mpam_has_feature(mpam_feat_mbw_part, rprops) &&

	    mpam_has_feature(mpam_feat_mbw_part, cfg)) {

		if (cfg->reset_mbw_pbm)

			mpam_reset_msc_bitmap(msc, MPAMCFG_MBW_PBM, rprops->mbw_pbm_bits);

		else

			mpam_write_partsel_reg(msc, MBW_PBM, cfg->mbw_pbm);

	}



	if (mpam_has_feature(mpam_feat_mbw_min, rprops))

	if (mpam_has_feature(mpam_feat_mbw_min, rprops) &&

	    mpam_has_feature(mpam_feat_mbw_min, cfg))

		mpam_write_partsel_reg(msc, MBW_MIN, 0);



	if (mpam_has_feature(mpam_feat_mbw_max, rprops))

	if (mpam_has_feature(mpam_feat_mbw_max, rprops) &&

	    mpam_has_feature(mpam_feat_mbw_max, cfg)) {

		if (cfg->reset_mbw_max)

			mpam_write_partsel_reg(msc, MBW_MAX, MPAMCFG_MBW_MAX_MAX);

		else

			mpam_write_partsel_reg(msc, MBW_MAX, cfg->mbw_max);

	}



	mutex_unlock(&msc->part_sel_lock);

}



static void mpam_init_reset_cfg(struct mpam_config *reset_cfg)

{

	*reset_cfg = (struct mpam_config) {

		.reset_cpbm = true,

		.reset_mbw_pbm = true,

		.reset_mbw_max = true,

	};

	bitmap_fill(reset_cfg->features, MPAM_FEATURE_LAST);

}



/*

 * Called via smp_call_on_cpu() to prevent migration, while still being

 * pre-emptible. Caller must hold mpam_srcu.
@@ -851,16 +891,19 @@ static void mpam_reset_ris_partid(struct mpam_msc_ris *ris, u16 partid) 
static int mpam_reset_ris(void *arg)

{

	u16 partid, partid_max;

	struct mpam_config reset_cfg;

	struct mpam_msc_ris *ris = arg;



	if (ris->in_reset_state)

		return 0;



	mpam_init_reset_cfg(&reset_cfg);



	spin_lock(&partid_max_lock);

	partid_max = mpam_partid_max;

	spin_unlock(&partid_max_lock);

	for (partid = 0; partid <= partid_max; partid++)

		mpam_reset_ris_partid(ris, partid);

		mpam_reprogram_ris_partid(ris, partid, &reset_cfg);



	return 0;

}
@@ -889,19 +932,58 @@ static int mpam_touch_msc(struct mpam_msc *msc, int (*fn)(void *a), void *arg) 
	return smp_call_on_cpu(mpam_get_msc_preferred_cpu(msc), fn, arg, true);

}



static void mpam_reset_msc(struct mpam_msc *msc, bool online)

{

struct mpam_write_config_arg {

	struct mpam_msc_ris *ris;

	struct mpam_component *comp;

	u16 partid;

};



	list_for_each_entry_srcu(ris, &msc->ris, msc_list, srcu_read_lock_held(&mpam_srcu)) {

		mpam_touch_msc(msc, &mpam_reset_ris, ris);

static int __write_config(void *arg)

{

	struct mpam_write_config_arg *c = arg;



	mpam_reprogram_ris_partid(c->ris, c->partid, &c->comp->cfg[c->partid]);



	return 0;

}



static void mpam_reprogram_msc(struct mpam_msc *msc)

{

	u16 partid;

	bool reset;

	struct mpam_config *cfg;

	struct mpam_msc_ris *ris;

	struct mpam_write_config_arg arg;



	/*

		 * Set in_reset_state when coming online. The reset state

		 * for non-zero partid may be lost while the CPUs are offline.

	 * No lock for mpam_partid_max as partid_max_published has been

	 * set by mpam_enabled(), so the values can no longer change.

	 */

		ris->in_reset_state = online;

	mpam_assert_partid_sizes_fixed();



	mutex_lock(&msc->cfg_lock);

	list_for_each_entry_srcu(ris, &msc->ris, msc_list,

				 srcu_read_lock_held(&mpam_srcu)) {

		if (!mpam_is_enabled() && !ris->in_reset_state) {

			mpam_touch_msc(msc, &mpam_reset_ris, ris);

			ris->in_reset_state = true;

			continue;

		}



		arg.comp = ris->vmsc->comp;

		arg.ris = ris;

		reset = true;

		for (partid = 0; partid <= mpam_partid_max; partid++) {

			cfg = &ris->vmsc->comp->cfg[partid];

			if (!bitmap_empty(cfg->features, MPAM_FEATURE_LAST))

				reset = false;



			arg.partid = partid;

			mpam_touch_msc(msc, __write_config, &arg);

		}

		ris->in_reset_state = reset;

	}

	mutex_unlock(&msc->cfg_lock);

}



static void _enable_percpu_irq(void *_irq)
@@ -925,7 +1007,7 @@ static int mpam_cpu_online(unsigned int cpu) 
			_enable_percpu_irq(&msc->reenable_error_ppi);



		if (atomic_fetch_inc(&msc->online_refs) == 0)

			mpam_reset_msc(msc, true);

			mpam_reprogram_msc(msc);

	}



	return 0;
@@ -980,8 +1062,22 @@ static int mpam_cpu_offline(unsigned int cpu) 
		if (msc->reenable_error_ppi)

			disable_percpu_irq(msc->reenable_error_ppi);



		if (atomic_dec_and_test(&msc->online_refs))

			mpam_reset_msc(msc, false);

		if (atomic_dec_and_test(&msc->online_refs)) {

			struct mpam_msc_ris *ris;



			mutex_lock(&msc->cfg_lock);

			list_for_each_entry_srcu(ris, &msc->ris, msc_list,

						 srcu_read_lock_held(&mpam_srcu)) {

				mpam_touch_msc(msc, &mpam_reset_ris, ris);



				/*

				 * The reset state for non-zero partid may be

				 * lost while the CPUs are offline.

				 */

				ris->in_reset_state = false;

			}

			mutex_unlock(&msc->cfg_lock);

		}

	}



	return 0;
@@ -1121,6 +1217,11 @@ static struct mpam_msc *do_mpam_msc_drv_probe(struct platform_device *pdev) 
	err = devm_mutex_init(dev, &msc->error_irq_lock);

	if (err)

		return ERR_PTR(err);



	err = devm_mutex_init(dev, &msc->cfg_lock);

	if (err)

		return ERR_PTR(err);



	mpam_mon_sel_lock_init(msc);

	msc->id = pdev->id;

	msc->pdev = pdev;
@@ -1581,6 +1682,72 @@ static void mpam_unregister_irqs(void) 
	}

}



static void __destroy_component_cfg(struct mpam_component *comp)

{

	add_to_garbage(comp->cfg);

}



static void mpam_reset_component_cfg(struct mpam_component *comp)

{

	int i;

	struct mpam_props *cprops = &comp->class->props;



	mpam_assert_partid_sizes_fixed();



	if (!comp->cfg)

		return;



	for (i = 0; i <= mpam_partid_max; i++) {

		comp->cfg[i] = (struct mpam_config) {};

		if (cprops->cpbm_wd)

			comp->cfg[i].cpbm = GENMASK(cprops->cpbm_wd - 1, 0);

		if (cprops->mbw_pbm_bits)

			comp->cfg[i].mbw_pbm = GENMASK(cprops->mbw_pbm_bits - 1, 0);

		if (cprops->bwa_wd)

			comp->cfg[i].mbw_max = GENMASK(15, 16 - cprops->bwa_wd);

	}

}



static int __allocate_component_cfg(struct mpam_component *comp)

{

	mpam_assert_partid_sizes_fixed();



	if (comp->cfg)

		return 0;



	comp->cfg = kcalloc(mpam_partid_max + 1, sizeof(*comp->cfg), GFP_KERNEL);

	if (!comp->cfg)

		return -ENOMEM;



	/*

	 * The array is free()d in one go, so only cfg[0]'s structure needs

	 * to be initialised.

	 */

	init_garbage(&comp->cfg[0].garbage);



	mpam_reset_component_cfg(comp);



	return 0;

}



static int mpam_allocate_config(void)

{

	struct mpam_class *class;

	struct mpam_component *comp;



	lockdep_assert_held(&mpam_list_lock);



	list_for_each_entry(class, &mpam_classes, classes_list) {

		list_for_each_entry(comp, &class->components, class_list) {

			int err = __allocate_component_cfg(comp);

			if (err)

				return err;

		}

	}



	return 0;

}



static void mpam_enable_once(void)

{

	int err;
@@ -1600,15 +1767,25 @@ static void mpam_enable_once(void) 
	 */

	cpus_read_lock();

	mutex_lock(&mpam_list_lock);

	do {

		mpam_enable_merge_features(&mpam_classes);



		err = mpam_register_irqs();

		if (err) {

			pr_warn("Failed to register irqs: %d\n", err);

			break;

		}



		err = mpam_allocate_config();

		if (err) {

			pr_err("Failed to allocate configuration arrays.\n");

			break;

		}

	} while (0);

	mutex_unlock(&mpam_list_lock);

	cpus_read_unlock();



	if (err) {

		pr_warn("Failed to register irqs: %d\n", err);

		mpam_disable_reason = "Failed to enable.";

		schedule_work(&mpam_broken_work);

		return;
@@ -1628,6 +1805,9 @@ static void mpam_reset_component_locked(struct mpam_component *comp) 
	struct mpam_vmsc *vmsc;



	lockdep_assert_cpus_held();

	mpam_assert_partid_sizes_fixed();



	mpam_reset_component_cfg(comp);



	guard(srcu)(&mpam_srcu);

	list_for_each_entry_srcu(vmsc, &comp->vmsc, comp_list,
@@ -1728,6 +1908,64 @@ void mpam_enable(struct work_struct *work) 
		mpam_enable_once();

}



#define maybe_update_config(cfg, feature, newcfg, member, changes) do { \

	if (mpam_has_feature(feature, newcfg) &&			\

	    (newcfg)->member != (cfg)->member) {			\

		(cfg)->member = (newcfg)->member;			\

		mpam_set_feature(feature, cfg);				\

									\

		(changes) = true;					\

	}								\

} while (0)



static bool mpam_update_config(struct mpam_config *cfg,

			       const struct mpam_config *newcfg)

{

	bool has_changes = false;



	maybe_update_config(cfg, mpam_feat_cpor_part, newcfg, cpbm, has_changes);

	maybe_update_config(cfg, mpam_feat_mbw_part, newcfg, mbw_pbm, has_changes);

	maybe_update_config(cfg, mpam_feat_mbw_max, newcfg, mbw_max, has_changes);



	return has_changes;

}



int mpam_apply_config(struct mpam_component *comp, u16 partid,

		      struct mpam_config *cfg)

{

	struct mpam_write_config_arg arg;

	struct mpam_msc_ris *ris;

	struct mpam_vmsc *vmsc;

	struct mpam_msc *msc;



	lockdep_assert_cpus_held();



	/* Don't pass in the current config! */

	WARN_ON_ONCE(&comp->cfg[partid] == cfg);



	if (!mpam_update_config(&comp->cfg[partid], cfg))

		return 0;



	arg.comp = comp;

	arg.partid = partid;



	guard(srcu)(&mpam_srcu);

	list_for_each_entry_srcu(vmsc, &comp->vmsc, comp_list,

				 srcu_read_lock_held(&mpam_srcu)) {

		msc = vmsc->msc;



		mutex_lock(&msc->cfg_lock);

		list_for_each_entry_srcu(ris, &vmsc->ris, vmsc_list,

					 srcu_read_lock_held(&mpam_srcu)) {

			arg.ris = ris;

			mpam_touch_msc(msc, __write_config, &arg);

		}

		mutex_unlock(&msc->cfg_lock);

	}



	return 0;

}



static int __init mpam_msc_driver_init(void)

{

	if (!system_supports_mpam())

drivers/resctrl/mpam_internal.h

+27 −0
Original line number Diff line number Diff line
@@ -91,6 +91,9 @@ struct mpam_msc { 
	 */

	struct mutex		part_sel_lock;



	/* cfg_lock protects the msc configuration. */

	struct mutex		cfg_lock;



	/*

	 * mon_sel_lock protects access to the MSC hardware registers that are

	 * affected by MPAMCFG_MON_SEL, and the mbwu_state.
@@ -182,6 +185,21 @@ struct mpam_class { 
	struct mpam_garbage	garbage;

};



struct mpam_config {

	/* Which configuration values are valid. */

	DECLARE_BITMAP(features, MPAM_FEATURE_LAST);



	u32	cpbm;

	u32	mbw_pbm;

	u16	mbw_max;



	bool	reset_cpbm;

	bool	reset_mbw_pbm;

	bool	reset_mbw_max;



	struct mpam_garbage	garbage;

};



struct mpam_component {

	u32			comp_id;
@@ -190,6 +208,12 @@ struct mpam_component { 


	cpumask_t		affinity;



	/*

	 * Array of configuration values, indexed by partid.

	 * Read from cpuhp callbacks, hold the cpuhp lock when writing.

	 */

	struct mpam_config	*cfg;



	/* member of mpam_class:components */

	struct list_head	class_list;
@@ -249,6 +273,9 @@ extern u8 mpam_pmg_max; 
void mpam_enable(struct work_struct *work);

void mpam_disable(struct work_struct *work);



int mpam_apply_config(struct mpam_component *comp, u16 partid,

		      struct mpam_config *cfg);



int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level,

				   cpumask_t *affinity);