Commit 21ac9fc8 authored by James Morse's avatar James Morse Committed by Zeng Heng
Browse files

arm_mpam: Track bandwidth counter state for overflow and power management 

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/snapshot/v6.7-rc2



---------------------------

Bandwidth counters need to run continuously to correctly reflect the
bandwidth.

The value read may be lower than the previous value read in the case
of overflow and when the hardware is reset due to CPU hotplug.

Add struct mbwu_state to track the bandwidth counter to allow overflow
and power management to be handled.

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarZeng Heng <zengheng4@huawei.com>
parent bb66b4d1

drivers/platform/mpam/mpam_devices.c

+145 −3
Original line number Diff line number Diff line
@@ -773,6 +773,7 @@ static void gen_msmon_ctl_flt_vals(struct mon_read *m, u32 *ctl_val, 
	*ctl_val |= MSMON_CFG_x_CTL_MATCH_PARTID;



	*flt_val = FIELD_PREP(MSMON_CFG_MBWU_FLT_PARTID, ctx->partid);

	*flt_val |= FIELD_PREP(MSMON_CFG_MBWU_FLT_RWBW, ctx->opts);

	if (m->ctx->match_pmg) {

		*ctl_val |= MSMON_CFG_x_CTL_MATCH_PMG;

		*flt_val |= FIELD_PREP(MSMON_CFG_MBWU_FLT_PMG, ctx->pmg);
@@ -805,6 +806,7 @@ static void write_msmon_ctl_flt_vals(struct mon_read *m, u32 ctl_val, 
				     u32 flt_val)

{

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

	struct msmon_mbwu_state *mbwu_state;



	/*

	 * Write the ctl_val with the enable bit cleared, reset the counter,
@@ -822,21 +824,33 @@ static void write_msmon_ctl_flt_vals(struct mon_read *m, u32 ctl_val, 
		mpam_write_monsel_reg(msc, CFG_MBWU_CTL, ctl_val);

		mpam_write_monsel_reg(msc, MBWU, 0);

		mpam_write_monsel_reg(msc, CFG_MBWU_CTL, ctl_val|MSMON_CFG_x_CTL_EN);



		mbwu_state = &m->ris->mbwu_state[m->ctx->mon];

		if (mbwu_state)

			mbwu_state->prev_val = 0;



		break;

	default:

		return;

	}

}



static u64 mpam_msmon_overflow_val(struct mpam_msc_ris *ris)

{

	/* TODO: scaling, and long counters */

	return GENMASK_ULL(30, 0);

}



static void __ris_msmon_read(void *arg)

{

	u64 now;

	bool nrdy = false;

	unsigned long flags;

	struct mon_read *m = arg;

	u64 now, overflow_val = 0;

	struct mon_cfg *ctx = m->ctx;

	struct mpam_msc_ris *ris = m->ris;

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

	struct msmon_mbwu_state *mbwu_state;

	u32 mon_sel, ctl_val, flt_val, cur_ctl, cur_flt;



	lockdep_assert_held(&msc->lock);
@@ -858,22 +872,41 @@ static void __ris_msmon_read(void *arg) 
	switch (m->type) {

	case mpam_feat_msmon_csu:

		now = mpam_read_monsel_reg(msc, CSU);

		nrdy = now & MSMON___NRDY;

		now = FIELD_GET(MSMON___VALUE, now);

		break;

	case mpam_feat_msmon_mbwu:

		now = mpam_read_monsel_reg(msc, MBWU);

		nrdy = now & MSMON___NRDY;

		now = FIELD_GET(MSMON___VALUE, now);



		if (nrdy)

			break;



		mbwu_state = &ris->mbwu_state[ctx->mon];

		if (!mbwu_state)

			break;



		/* Add any pre-overflow value to the mbwu_state->val */

		if (mbwu_state->prev_val > now)

			overflow_val = mpam_msmon_overflow_val(ris) - mbwu_state->prev_val;



		mbwu_state->prev_val = now;

		mbwu_state->correction += overflow_val;



		/* Include bandwidth consumed before the last hardware reset */

		now += mbwu_state->correction;

		break;

	default:

		return;

	}

	spin_unlock_irqrestore(&msc->mon_sel_lock, flags);



	nrdy = now & MSMON___NRDY;

	if (nrdy) {

		m->err = -EBUSY;

		return;

	}



	now = FIELD_GET(MSMON___VALUE, now);

	*(m->val) += now;

}
@@ -1064,6 +1097,68 @@ static int mpam_reprogram_ris(void *_arg) 
	return 0;

}



static int mpam_restore_mbwu_state(void *_ris)

{

	int i;

	struct mon_read mwbu_arg;

	struct mpam_msc_ris *ris = _ris;



	lockdep_assert_held(&ris->msc->lock);



	for (i = 0; i < ris->props.num_mbwu_mon; i++) {

		if (ris->mbwu_state[i].enabled) {

			mwbu_arg.ris = ris;

			mwbu_arg.ctx = &ris->mbwu_state[i].cfg;

			mwbu_arg.type = mpam_feat_msmon_mbwu;



			__ris_msmon_read(&mwbu_arg);

		}

	}



	return 0;

}



static int mpam_save_mbwu_state(void *arg)

{

	int i;

	u64 val;

	struct mon_cfg *cfg;

	unsigned long flags;

	u32 cur_flt, cur_ctl, mon_sel;

	struct mpam_msc_ris *ris = arg;

	struct mpam_msc *msc = ris->msc;

	struct msmon_mbwu_state *mbwu_state;



	lockdep_assert_held(&msc->lock);



	for (i = 0; i < ris->props.num_mbwu_mon; i++) {

		mbwu_state = &ris->mbwu_state[i];

		cfg = &mbwu_state->cfg;



		spin_lock_irqsave(&msc->mon_sel_lock, flags);

		mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, i) |

			  FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx);

		mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel);



		cur_flt = mpam_read_monsel_reg(msc, CFG_MBWU_FLT);

		cur_ctl = mpam_read_monsel_reg(msc, CFG_MBWU_CTL);

		mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0);



		val = mpam_read_monsel_reg(msc, MBWU);

		mpam_write_monsel_reg(msc, MBWU, 0);



		cfg->mon = i;

		cfg->pmg = FIELD_GET(MSMON_CFG_MBWU_FLT_PMG, cur_flt);

		cfg->match_pmg = FIELD_GET(MSMON_CFG_x_CTL_MATCH_PMG, cur_ctl);

		cfg->partid = FIELD_GET(MSMON_CFG_MBWU_FLT_PARTID, cur_flt);

		mbwu_state->correction += val;

		mbwu_state->enabled = FIELD_GET(MSMON_CFG_x_CTL_EN, cur_ctl);

		spin_unlock_irqrestore(&msc->mon_sel_lock, flags);

	}



	return 0;

}



/*

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

 * pre-emptible.
@@ -1125,6 +1220,9 @@ static void mpam_reset_msc(struct mpam_msc *msc, bool online) 
		 * for non-zero partid may be lost while the CPUs are offline.

		 */

		ris->in_reset_state = online;



		if (mpam_is_enabled() && !online)

			mpam_touch_msc(msc, &mpam_save_mbwu_state, ris);

	}

	srcu_read_unlock(&mpam_srcu, idx);

}
@@ -1156,6 +1254,9 @@ static void mpam_reprogram_msc(struct mpam_msc *msc) 
			mpam_reprogram_ris_partid(ris, partid, cfg);

		}

		ris->in_reset_state = reset;



		if (mpam_has_feature(mpam_feat_msmon_mbwu, &ris->props))

			mpam_touch_msc(msc, &mpam_restore_mbwu_state, ris);

	}

	srcu_read_unlock(&mpam_srcu, idx);

}
@@ -1814,8 +1915,31 @@ static void mpam_unregister_irqs(void) 
	cpus_read_unlock();

}



static void __destroy_component_cfg(struct mpam_component *comp)

{

	unsigned long flags;

	struct mpam_msc_ris *ris;

	struct msmon_mbwu_state *mbwu_state;



	kfree(comp->cfg);

	list_for_each_entry(ris, &comp->ris, comp_list) {

		mutex_lock(&ris->msc->lock);

		spin_lock_irqsave(&ris->msc->mon_sel_lock, flags);

		mbwu_state = ris->mbwu_state;

		ris->mbwu_state = NULL;

		spin_unlock_irqrestore(&ris->msc->mon_sel_lock, flags);

		mutex_unlock(&ris->msc->lock);



		kfree(mbwu_state);

	}

}



static int __allocate_component_cfg(struct mpam_component *comp)

{

	unsigned long flags;

	struct mpam_msc_ris *ris;

	struct msmon_mbwu_state *mbwu_state;



	if (comp->cfg)

		return 0;
@@ -1823,6 +1947,24 @@ static int __allocate_component_cfg(struct mpam_component *comp) 
	if (!comp->cfg)

		return -ENOMEM;



	list_for_each_entry(ris, &comp->ris, comp_list) {

		if (!ris->props.num_mbwu_mon)

			continue;



		mbwu_state = kcalloc(ris->props.num_mbwu_mon,

				     sizeof(*ris->mbwu_state), GFP_KERNEL);

		if (!mbwu_state) {

			__destroy_component_cfg(comp);

			return -ENOMEM;

		}



		mutex_lock(&ris->msc->lock);

		spin_lock_irqsave(&ris->msc->mon_sel_lock, flags);

		ris->mbwu_state = mbwu_state;

		spin_unlock_irqrestore(&ris->msc->mon_sel_lock, flags);

		mutex_unlock(&ris->msc->lock);

	}



	return 0;

}

drivers/platform/mpam/mpam_internal.h

+36 −16
Original line number Diff line number Diff line
@@ -175,8 +175,40 @@ struct mpam_component 
	struct mpam_class	*class;

};



struct mpam_msc_ris

{

/* The values for MSMON_CFG_MBWU_FLT.RWBW */

enum mon_filter_options {

	COUNT_BOTH	= 0,

	COUNT_WRITE	= 1,

	COUNT_READ	= 2,

};



struct mon_cfg {

	u16                     mon;

	u8                      pmg;

	bool                    match_pmg;

	u32                     partid;

	enum mon_filter_options opts;

};



/*

 * Changes to enabled and cfg are protected by the msc->lock.

 * Changes to prev_val and correction are protected by the msc's mon_sel_lock.

 */

struct msmon_mbwu_state {

	bool		enabled;

	struct mon_cfg	cfg;



	/* The value last read from the hardware. Used to detect overflow. */

	u64		prev_val;



	/*

	 * The value to add to the new reading to account for power management,

	 * and shifts to trigger the overflow interrupt.

	 */

	u64		correction;

};



struct mpam_msc_ris {

	u8			ris_idx;

	u64			idr;

	struct mpam_props	props;
@@ -193,21 +225,9 @@ struct mpam_msc_ris 
	/* parents: */

	struct mpam_msc		*msc;

	struct mpam_component	*comp;

};



/* The values for MSMON_CFG_MBWU_FLT.RWBW */

enum mon_filter_options {

	COUNT_BOTH	= 0,

	COUNT_WRITE	= 1,

	COUNT_READ	= 2,

};



struct mon_cfg {

	u16                     mon;

	u8                      pmg;

	bool                    match_pmg;

	u32                     partid;

	enum mon_filter_options opts;

	/* msmon mbwu configuration is preserved over reset */

	struct msmon_mbwu_state	*mbwu_state;

};



static inline int mpam_alloc_csu_mon(struct mpam_class *class)