Commit 201d96ca authored by James Morse's avatar James Morse Committed by Catalin Marinas
Browse files

arm_mpam: Add helper to reset saved mbwu state 



resctrl expects to reset the bandwidth counters when the filesystem
is mounted.

To allow this, add a helper that clears the saved mbwu state. Instead
of cross calling to each CPU that can access the component MSC to
write to the counter, set a flag that causes it to be zero'd on the
the next read. This is easily done by forcing a configuration update.

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Cc: Peter Newman <peternewman@google.com>
Reviewed-by: default avatarFenghua Yu <fenghuay@nvdia.com>
Reviewed-by: default avatarGavin Shan <gshan@redhat.com>
Reviewed-by: default avatarJonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: default avatarShaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-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 9e5afb7c

drivers/resctrl/mpam_devices.c

+47 −1
Original line number Diff line number Diff line
@@ -1075,6 +1075,7 @@ static void __ris_msmon_read(void *arg) 
	bool overflow;

	struct mon_read *m = arg;

	struct mon_cfg *ctx = m->ctx;

	bool reset_on_next_read = false;

	struct mpam_msc_ris *ris = m->ris;

	struct msmon_mbwu_state *mbwu_state;

	struct mpam_props *rprops = &ris->props;
@@ -1089,6 +1090,20 @@ static void __ris_msmon_read(void *arg) 
		  FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx);

	mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel);



	switch (m->type) {

	case mpam_feat_msmon_mbwu_31counter:

	case mpam_feat_msmon_mbwu_44counter:

	case mpam_feat_msmon_mbwu_63counter:

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

		if (mbwu_state) {

			reset_on_next_read = mbwu_state->reset_on_next_read;

			mbwu_state->reset_on_next_read = false;

		}

		break;

	default:

		break;

	}



	/*

	 * Read the existing configuration to avoid re-writing the same values.

	 * This saves waiting for 'nrdy' on subsequent reads.
@@ -1106,7 +1121,7 @@ static void __ris_msmon_read(void *arg) 
	config_mismatch = cur_flt != flt_val ||

			  cur_ctl != (ctl_val | MSMON_CFG_x_CTL_EN);



	if (config_mismatch) {

	if (config_mismatch || reset_on_next_read) {

		write_msmon_ctl_flt_vals(m, ctl_val, flt_val);

		overflow = false;

	} else if (overflow) {
@@ -1263,6 +1278,37 @@ int mpam_msmon_read(struct mpam_component *comp, struct mon_cfg *ctx, 
	return err;

}



void mpam_msmon_reset_mbwu(struct mpam_component *comp, struct mon_cfg *ctx)

{

	struct mpam_msc *msc;

	struct mpam_vmsc *vmsc;

	struct mpam_msc_ris *ris;



	if (!mpam_is_enabled())

		return;



	guard(srcu)(&mpam_srcu);

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

				 srcu_read_lock_held(&mpam_srcu)) {

		if (!mpam_has_feature(mpam_feat_msmon_mbwu, &vmsc->props))

			continue;



		msc = vmsc->msc;

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

					 srcu_read_lock_held(&mpam_srcu)) {

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

				continue;



			if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc)))

				continue;



			ris->mbwu_state[ctx->mon].correction = 0;

			ris->mbwu_state[ctx->mon].reset_on_next_read = true;

			mpam_mon_sel_unlock(msc);

		}

	}

}



static void mpam_reset_msc_bitmap(struct mpam_msc *msc, u16 reg, u16 wd)

{

	u32 num_words, msb;

drivers/resctrl/mpam_internal.h

+2 −0
Original line number Diff line number Diff line
@@ -211,6 +211,7 @@ struct mon_cfg { 
/* Changes to msmon_mbwu_state are protected by the msc's mon_sel_lock. */

struct msmon_mbwu_state {

	bool		enabled;

	bool		reset_on_next_read;

	struct mon_cfg	cfg;



	/*
@@ -370,6 +371,7 @@ int mpam_apply_config(struct mpam_component *comp, u16 partid, 


int mpam_msmon_read(struct mpam_component *comp, struct mon_cfg *ctx,

		    enum mpam_device_features, u64 *val);

void mpam_msmon_reset_mbwu(struct mpam_component *comp, struct mon_cfg *ctx);



int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level,

				   cpumask_t *affinity);