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Commit e0bdfe8e authored by Reinette Chatre's avatar Reinette Chatre Committed by Thomas Gleixner
Browse files

x86/intel_rdt: Support creation/removal of pseudo-locked region 



The user triggers the creation of a pseudo-locked region when writing a
valid schemata to the schemata file of a resource group in the
pseudo-locksetup mode.

A valid schemata is one that: (1) does not overlap with any other resource
group, (2) does not involve a cache that already contains a pseudo-locked
region within its hierarchy.

After a valid schemata is parsed the system is programmed to associate the
to be pseudo-lock bitmask with the closid associated with the resource
group. With the system set up the pseudo-locked region can be created.

Signed-off-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: vikas.shivappa@linux.intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/8929c3a9e2ba600e79649abe584aa28b8d0ff639.1529706536.git.reinette.chatre@intel.com
parent 018961ae

arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c

+42 −0
Original line number Diff line number Diff line
@@ -143,9 +143,26 @@ int parse_cbm(void *_data, struct rdt_resource *r, struct rdt_domain *d) 
		return -EINVAL;

	}



	/*

	 * Cannot set up more than one pseudo-locked region in a cache

	 * hierarchy.

	 */

	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&

	    rdtgroup_pseudo_locked_in_hierarchy(d)) {

		rdt_last_cmd_printf("pseudo-locked region in hierarchy\n");

		return -EINVAL;

	}



	if (!cbm_validate(data->buf, &cbm_val, r))

		return -EINVAL;



	if ((rdtgrp->mode == RDT_MODE_EXCLUSIVE ||

	     rdtgrp->mode == RDT_MODE_SHAREABLE) &&

	    rdtgroup_cbm_overlaps_pseudo_locked(d, cbm_val)) {

		rdt_last_cmd_printf("CBM overlaps with pseudo-locked region\n");

		return -EINVAL;

	}



	/*

	 * The CBM may not overlap with the CBM of another closid if

	 * either is exclusive.
@@ -199,6 +216,21 @@ static int parse_line(char *line, struct rdt_resource *r, 
			data.rdtgrp = rdtgrp;

			if (r->parse_ctrlval(&data, r, d))

				return -EINVAL;

			if (rdtgrp->mode ==  RDT_MODE_PSEUDO_LOCKSETUP) {

				/*

				 * In pseudo-locking setup mode and just

				 * parsed a valid CBM that should be

				 * pseudo-locked. Only one locked region per

				 * resource group and domain so just do

				 * the required initialization for single

				 * region and return.

				 */

				rdtgrp->plr->r = r;

				rdtgrp->plr->d = d;

				rdtgrp->plr->cbm = d->new_ctrl;

				d->plr = rdtgrp->plr;

				return 0;

			}

			goto next;

		}

	}
@@ -322,6 +354,16 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of, 
			goto out;

	}



	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {

		/*

		 * If pseudo-locking fails we keep the resource group in

		 * mode RDT_MODE_PSEUDO_LOCKSETUP with its class of service

		 * active and updated for just the domain the pseudo-locked

		 * region was requested for.

		 */

		ret = rdtgroup_pseudo_lock_create(rdtgrp);

	}



out:

	rdtgroup_kn_unlock(of->kn);

	return ret ?: nbytes;

arch/x86/kernel/cpu/intel_rdt_rdtgroup.c

+20 −5
Original line number Diff line number Diff line
@@ -1771,6 +1771,9 @@ void rdtgroup_kn_unlock(struct kernfs_node *kn) 


	if (atomic_dec_and_test(&rdtgrp->waitcount) &&

	    (rdtgrp->flags & RDT_DELETED)) {

		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||

		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)

			rdtgroup_pseudo_lock_remove(rdtgrp);

		kernfs_unbreak_active_protection(kn);

		kernfs_put(rdtgrp->kn);

		kfree(rdtgrp);
@@ -2002,6 +2005,10 @@ static void rmdir_all_sub(void) 
		if (rdtgrp == &rdtgroup_default)

			continue;



		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||

		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)

			rdtgroup_pseudo_lock_remove(rdtgrp);



		/*

		 * Give any CPUs back to the default group. We cannot copy

		 * cpu_online_mask because a CPU might have executed the
@@ -2313,6 +2320,8 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) 
						d->new_ctrl |= *ctrl;

				}

			}

			if (d->plr && d->plr->cbm > 0)

				used_b |= d->plr->cbm;

			unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1);

			unused_b &= BIT_MASK(r->cache.cbm_len) - 1;

			d->new_ctrl |= unused_b;
@@ -2696,13 +2705,19 @@ static int rdtgroup_rmdir(struct kernfs_node *kn) 
	 * If the rdtgroup is a mon group and parent directory

	 * is a valid "mon_groups" directory, remove the mon group.

	 */

	if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn)

	if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn) {

		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||

		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {

			ret = rdtgroup_ctrl_remove(kn, rdtgrp);

		} else {

			ret = rdtgroup_rmdir_ctrl(kn, rdtgrp, tmpmask);

	else if (rdtgrp->type == RDTMON_GROUP &&

		 is_mon_groups(parent_kn, kn->name))

		}

	} else if (rdtgrp->type == RDTMON_GROUP &&

		 is_mon_groups(parent_kn, kn->name)) {

		ret = rdtgroup_rmdir_mon(kn, rdtgrp, tmpmask);

	else

	} else {

		ret = -EPERM;

	}



out:

	rdtgroup_kn_unlock(kn);