Commit 3622ff88 authored by Xingang Wang's avatar Xingang Wang Committed by Zheng Zengkai
Browse files

mpam: Add support for group rmid modify 

ascend inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4L735


CVE: NA

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

The mpam driver controls the allocation of rmid, however there
are some ocassions that the partid and pmg of a group might come
from elsewhere. This add support for group rmid modify. The
sysfs rmid file is set to write accessible, and this add a write
interface to accept rmid from user. When the rmid from user is
different and valid, update the group with new rmid. When error
occurs, rollback to old rmid.

Signed-off-by: default avatarXingang Wang <wangxingang5@huawei.com>
Reviewed-by: default avatarWang ShaoBo <bobo.shaobowang@huawei.com>
Reviewed-by: default avatarWeilong Chen <chenweilong@huawei.com>
Acked-by: default avatarXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 85dd77d6

arch/arm64/kernel/mpam/mpam_resctrl.c

+120 −8
Original line number Diff line number Diff line
@@ -803,6 +803,11 @@ static void unset_rmid_remap_bmp_occ(unsigned long *bmp) 
	set_bit(0, bmp);

}



static int is_rmid_remap_bmp_bdr_set(unsigned long *bmp, int b)

{

	return (test_bit(b + 1, bmp) == 0) ? 1 : 0;

}



static void rmid_remap_bmp_bdr_set(unsigned long *bmp, int b)

{

	set_bit(b + 1, bmp);
@@ -909,11 +914,11 @@ static int rmid_to_partid_pmg(int rmid, int *partid, int *pmg) 
	return 0;

}



static int __rmid_alloc(int partid)

static int __rmid_alloc(int partid, int pmg)

{

	int stride = 0;

	int partid_sel = 0;

	int ret, pmg;

	int ret;

	int rmid[2] = {-1, -1};

	unsigned long **cmp, **bmp;
@@ -928,10 +933,19 @@ static int __rmid_alloc(int partid) 
				continue;

			set_rmid_remap_bmp_occ(*bmp);



			if (pmg >= 0) {

				if (is_rmid_remap_bmp_bdr_set(*bmp, pmg)) {

					ret = -EEXIST;

					goto out;

				}

				rmid_remap_bmp_bdr_clear(*bmp, pmg);

			} else {

				ret = rmid_remap_bmp_alloc_pmg(*bmp);

				if (ret < 0)

					goto out;

				pmg = ret;

			}



			rmid[stride] = to_rmid(partid + stride, pmg);

			if (STRIDE_INC_CHK(stride))

				break;
@@ -971,7 +985,7 @@ static int __rmid_alloc(int partid) 


int rmid_alloc(int partid)

{

	return __rmid_alloc(partid);

	return __rmid_alloc(partid, -1);

}



void rmid_free(int rmid)
@@ -1809,6 +1823,103 @@ static int resctrl_group_rmid_show(struct kernfs_open_file *of, 
	return ret;

}



static ssize_t resctrl_group_rmid_write(struct kernfs_open_file *of,

		char *buf, size_t nbytes, loff_t off)

{

	struct rdtgroup *rdtgrp;

	int ret = 0;

	int partid;

	int pmg;

	int rmid;

	int old_rmid;

	int old_reqpartid;

	struct task_struct *p, *t;



	if (kstrtoint(strstrip(buf), 0, &rmid) || rmid < 0)

		return -EINVAL;



	rdtgrp = resctrl_group_kn_lock_live(of->kn);

	if (!rdtgrp) {

		ret = -ENOENT;

		goto unlock;

	}



	rdt_last_cmd_clear();



	if (rmid == 0 || rdtgrp->mon.rmid == 0) {

		ret = -EINVAL;

		goto unlock;

	}



	ret = rmid_to_partid_pmg(rmid, &partid, &pmg);

	if (ret < 0) {

		ret = -EINVAL;

		goto unlock;

	}



	if (rmid == rdtgrp->mon.rmid)

		goto unlock;



	if (rdtgrp->type != RDTCTRL_GROUP ||

			!list_empty(&rdtgrp->mon.crdtgrp_list)) {

		rdt_last_cmd_puts("unsupported operation\n");

		goto unlock;

	}



	ret = __rmid_alloc(partid, pmg);

	if (ret < 0) {

		rdt_last_cmd_puts("set rmid failed\n");

		goto unlock;

	}



	old_rmid = rdtgrp->mon.rmid;

	old_reqpartid = rdtgrp->closid.reqpartid;



	/*

	 * we use intpartid as group control, use reqpartid for config

	 * synchronization and monitor, only update the reqpartid

	 */

	rdtgrp->closid.reqpartid = partid;

	rdtgrp->mon.rmid = rmid;



	read_lock(&tasklist_lock);

	for_each_process_thread(p, t) {

		if (t->closid == rdtgrp->closid.intpartid) {

			ret = __resctrl_group_move_task(t, rdtgrp);

			if (ret) {

				read_unlock(&tasklist_lock);

				goto rollback;

			}

		}

	}

	read_unlock(&tasklist_lock);



	update_closid_rmid(&rdtgrp->cpu_mask, rdtgrp);

	rmid_free(old_rmid);



unlock:

	resctrl_group_kn_unlock(of->kn);

	if (ret)

		return ret;



	return nbytes;



rollback:

	rdtgrp->mon.rmid = old_rmid;

	rdtgrp->closid.reqpartid = old_reqpartid;



	read_lock(&tasklist_lock);

	for_each_process_thread(p, t) {

		if (t->closid == rdtgrp->closid.intpartid)

			WARN_ON_ONCE(__resctrl_group_move_task(t, rdtgrp));

	}

	read_unlock(&tasklist_lock);



	rmid_free(rmid);

	resctrl_group_kn_unlock(of->kn);

	return ret;

}



/* rdtgroup information files for one cache resource. */

static struct rftype res_specific_files[] = {

	{
@@ -1908,8 +2019,9 @@ static struct rftype res_specific_files[] = { 
	},

	{

		.name		= "rmid",

		.mode		= 0444,

		.mode		= 0644,

		.kf_ops		= &resctrl_group_kf_single_ops,

		.write		= resctrl_group_rmid_write,

		.seq_show	= resctrl_group_rmid_show,

		.fflags		= RFTYPE_BASE,

	},