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1// SPDX-License-Identifier: GPL-2.02/*3 * DAMON sysfs Interface4 *5 * Copyright (c) 2022 SeongJae Park <sj@kernel.org>6 */7 8#include <linux/pid.h>9#include <linux/sched.h>10#include <linux/slab.h>11 12#include "sysfs-common.h"13 14/*15 * init region directory16 */17 18struct damon_sysfs_region {19	struct kobject kobj;20	struct damon_addr_range ar;21};22 23static struct damon_sysfs_region *damon_sysfs_region_alloc(void)24{25	return kzalloc(sizeof(struct damon_sysfs_region), GFP_KERNEL);26}27 28static ssize_t start_show(struct kobject *kobj, struct kobj_attribute *attr,29		char *buf)30{31	struct damon_sysfs_region *region = container_of(kobj,32			struct damon_sysfs_region, kobj);33 34	return sysfs_emit(buf, "%lu\n", region->ar.start);35}36 37static ssize_t start_store(struct kobject *kobj, struct kobj_attribute *attr,38		const char *buf, size_t count)39{40	struct damon_sysfs_region *region = container_of(kobj,41			struct damon_sysfs_region, kobj);42	int err = kstrtoul(buf, 0, &region->ar.start);43 44	return err ? err : count;45}46 47static ssize_t end_show(struct kobject *kobj, struct kobj_attribute *attr,48		char *buf)49{50	struct damon_sysfs_region *region = container_of(kobj,51			struct damon_sysfs_region, kobj);52 53	return sysfs_emit(buf, "%lu\n", region->ar.end);54}55 56static ssize_t end_store(struct kobject *kobj, struct kobj_attribute *attr,57		const char *buf, size_t count)58{59	struct damon_sysfs_region *region = container_of(kobj,60			struct damon_sysfs_region, kobj);61	int err = kstrtoul(buf, 0, &region->ar.end);62 63	return err ? err : count;64}65 66static void damon_sysfs_region_release(struct kobject *kobj)67{68	kfree(container_of(kobj, struct damon_sysfs_region, kobj));69}70 71static struct kobj_attribute damon_sysfs_region_start_attr =72		__ATTR_RW_MODE(start, 0600);73 74static struct kobj_attribute damon_sysfs_region_end_attr =75		__ATTR_RW_MODE(end, 0600);76 77static struct attribute *damon_sysfs_region_attrs[] = {78	&damon_sysfs_region_start_attr.attr,79	&damon_sysfs_region_end_attr.attr,80	NULL,81};82ATTRIBUTE_GROUPS(damon_sysfs_region);83 84static const struct kobj_type damon_sysfs_region_ktype = {85	.release = damon_sysfs_region_release,86	.sysfs_ops = &kobj_sysfs_ops,87	.default_groups = damon_sysfs_region_groups,88};89 90/*91 * init_regions directory92 */93 94struct damon_sysfs_regions {95	struct kobject kobj;96	struct damon_sysfs_region **regions_arr;97	int nr;98};99 100static struct damon_sysfs_regions *damon_sysfs_regions_alloc(void)101{102	return kzalloc(sizeof(struct damon_sysfs_regions), GFP_KERNEL);103}104 105static void damon_sysfs_regions_rm_dirs(struct damon_sysfs_regions *regions)106{107	struct damon_sysfs_region **regions_arr = regions->regions_arr;108	int i;109 110	for (i = 0; i < regions->nr; i++)111		kobject_put(&regions_arr[i]->kobj);112	regions->nr = 0;113	kfree(regions_arr);114	regions->regions_arr = NULL;115}116 117static int damon_sysfs_regions_add_dirs(struct damon_sysfs_regions *regions,118		int nr_regions)119{120	struct damon_sysfs_region **regions_arr, *region;121	int err, i;122 123	damon_sysfs_regions_rm_dirs(regions);124	if (!nr_regions)125		return 0;126 127	regions_arr = kmalloc_array(nr_regions, sizeof(*regions_arr),128			GFP_KERNEL | __GFP_NOWARN);129	if (!regions_arr)130		return -ENOMEM;131	regions->regions_arr = regions_arr;132 133	for (i = 0; i < nr_regions; i++) {134		region = damon_sysfs_region_alloc();135		if (!region) {136			damon_sysfs_regions_rm_dirs(regions);137			return -ENOMEM;138		}139 140		err = kobject_init_and_add(&region->kobj,141				&damon_sysfs_region_ktype, &regions->kobj,142				"%d", i);143		if (err) {144			kobject_put(&region->kobj);145			damon_sysfs_regions_rm_dirs(regions);146			return err;147		}148 149		regions_arr[i] = region;150		regions->nr++;151	}152	return 0;153}154 155static ssize_t nr_regions_show(struct kobject *kobj,156		struct kobj_attribute *attr, char *buf)157{158	struct damon_sysfs_regions *regions = container_of(kobj,159			struct damon_sysfs_regions, kobj);160 161	return sysfs_emit(buf, "%d\n", regions->nr);162}163 164static ssize_t nr_regions_store(struct kobject *kobj,165		struct kobj_attribute *attr, const char *buf, size_t count)166{167	struct damon_sysfs_regions *regions;168	int nr, err = kstrtoint(buf, 0, &nr);169 170	if (err)171		return err;172	if (nr < 0)173		return -EINVAL;174 175	regions = container_of(kobj, struct damon_sysfs_regions, kobj);176 177	if (!mutex_trylock(&damon_sysfs_lock))178		return -EBUSY;179	err = damon_sysfs_regions_add_dirs(regions, nr);180	mutex_unlock(&damon_sysfs_lock);181	if (err)182		return err;183 184	return count;185}186 187static void damon_sysfs_regions_release(struct kobject *kobj)188{189	kfree(container_of(kobj, struct damon_sysfs_regions, kobj));190}191 192static struct kobj_attribute damon_sysfs_regions_nr_attr =193		__ATTR_RW_MODE(nr_regions, 0600);194 195static struct attribute *damon_sysfs_regions_attrs[] = {196	&damon_sysfs_regions_nr_attr.attr,197	NULL,198};199ATTRIBUTE_GROUPS(damon_sysfs_regions);200 201static const struct kobj_type damon_sysfs_regions_ktype = {202	.release = damon_sysfs_regions_release,203	.sysfs_ops = &kobj_sysfs_ops,204	.default_groups = damon_sysfs_regions_groups,205};206 207/*208 * target directory209 */210 211struct damon_sysfs_target {212	struct kobject kobj;213	struct damon_sysfs_regions *regions;214	int pid;215};216 217static struct damon_sysfs_target *damon_sysfs_target_alloc(void)218{219	return kzalloc(sizeof(struct damon_sysfs_target), GFP_KERNEL);220}221 222static int damon_sysfs_target_add_dirs(struct damon_sysfs_target *target)223{224	struct damon_sysfs_regions *regions = damon_sysfs_regions_alloc();225	int err;226 227	if (!regions)228		return -ENOMEM;229 230	err = kobject_init_and_add(&regions->kobj, &damon_sysfs_regions_ktype,231			&target->kobj, "regions");232	if (err)233		kobject_put(&regions->kobj);234	else235		target->regions = regions;236	return err;237}238 239static void damon_sysfs_target_rm_dirs(struct damon_sysfs_target *target)240{241	damon_sysfs_regions_rm_dirs(target->regions);242	kobject_put(&target->regions->kobj);243}244 245static ssize_t pid_target_show(struct kobject *kobj,246		struct kobj_attribute *attr, char *buf)247{248	struct damon_sysfs_target *target = container_of(kobj,249			struct damon_sysfs_target, kobj);250 251	return sysfs_emit(buf, "%d\n", target->pid);252}253 254static ssize_t pid_target_store(struct kobject *kobj,255		struct kobj_attribute *attr, const char *buf, size_t count)256{257	struct damon_sysfs_target *target = container_of(kobj,258			struct damon_sysfs_target, kobj);259	int err = kstrtoint(buf, 0, &target->pid);260 261	if (err)262		return -EINVAL;263	return count;264}265 266static void damon_sysfs_target_release(struct kobject *kobj)267{268	kfree(container_of(kobj, struct damon_sysfs_target, kobj));269}270 271static struct kobj_attribute damon_sysfs_target_pid_attr =272		__ATTR_RW_MODE(pid_target, 0600);273 274static struct attribute *damon_sysfs_target_attrs[] = {275	&damon_sysfs_target_pid_attr.attr,276	NULL,277};278ATTRIBUTE_GROUPS(damon_sysfs_target);279 280static const struct kobj_type damon_sysfs_target_ktype = {281	.release = damon_sysfs_target_release,282	.sysfs_ops = &kobj_sysfs_ops,283	.default_groups = damon_sysfs_target_groups,284};285 286/*287 * targets directory288 */289 290struct damon_sysfs_targets {291	struct kobject kobj;292	struct damon_sysfs_target **targets_arr;293	int nr;294};295 296static struct damon_sysfs_targets *damon_sysfs_targets_alloc(void)297{298	return kzalloc(sizeof(struct damon_sysfs_targets), GFP_KERNEL);299}300 301static void damon_sysfs_targets_rm_dirs(struct damon_sysfs_targets *targets)302{303	struct damon_sysfs_target **targets_arr = targets->targets_arr;304	int i;305 306	for (i = 0; i < targets->nr; i++) {307		damon_sysfs_target_rm_dirs(targets_arr[i]);308		kobject_put(&targets_arr[i]->kobj);309	}310	targets->nr = 0;311	kfree(targets_arr);312	targets->targets_arr = NULL;313}314 315static int damon_sysfs_targets_add_dirs(struct damon_sysfs_targets *targets,316		int nr_targets)317{318	struct damon_sysfs_target **targets_arr, *target;319	int err, i;320 321	damon_sysfs_targets_rm_dirs(targets);322	if (!nr_targets)323		return 0;324 325	targets_arr = kmalloc_array(nr_targets, sizeof(*targets_arr),326			GFP_KERNEL | __GFP_NOWARN);327	if (!targets_arr)328		return -ENOMEM;329	targets->targets_arr = targets_arr;330 331	for (i = 0; i < nr_targets; i++) {332		target = damon_sysfs_target_alloc();333		if (!target) {334			damon_sysfs_targets_rm_dirs(targets);335			return -ENOMEM;336		}337 338		err = kobject_init_and_add(&target->kobj,339				&damon_sysfs_target_ktype, &targets->kobj,340				"%d", i);341		if (err)342			goto out;343 344		err = damon_sysfs_target_add_dirs(target);345		if (err)346			goto out;347 348		targets_arr[i] = target;349		targets->nr++;350	}351	return 0;352 353out:354	damon_sysfs_targets_rm_dirs(targets);355	kobject_put(&target->kobj);356	return err;357}358 359static ssize_t nr_targets_show(struct kobject *kobj,360		struct kobj_attribute *attr, char *buf)361{362	struct damon_sysfs_targets *targets = container_of(kobj,363			struct damon_sysfs_targets, kobj);364 365	return sysfs_emit(buf, "%d\n", targets->nr);366}367 368static ssize_t nr_targets_store(struct kobject *kobj,369		struct kobj_attribute *attr, const char *buf, size_t count)370{371	struct damon_sysfs_targets *targets;372	int nr, err = kstrtoint(buf, 0, &nr);373 374	if (err)375		return err;376	if (nr < 0)377		return -EINVAL;378 379	targets = container_of(kobj, struct damon_sysfs_targets, kobj);380 381	if (!mutex_trylock(&damon_sysfs_lock))382		return -EBUSY;383	err = damon_sysfs_targets_add_dirs(targets, nr);384	mutex_unlock(&damon_sysfs_lock);385	if (err)386		return err;387 388	return count;389}390 391static void damon_sysfs_targets_release(struct kobject *kobj)392{393	kfree(container_of(kobj, struct damon_sysfs_targets, kobj));394}395 396static struct kobj_attribute damon_sysfs_targets_nr_attr =397		__ATTR_RW_MODE(nr_targets, 0600);398 399static struct attribute *damon_sysfs_targets_attrs[] = {400	&damon_sysfs_targets_nr_attr.attr,401	NULL,402};403ATTRIBUTE_GROUPS(damon_sysfs_targets);404 405static const struct kobj_type damon_sysfs_targets_ktype = {406	.release = damon_sysfs_targets_release,407	.sysfs_ops = &kobj_sysfs_ops,408	.default_groups = damon_sysfs_targets_groups,409};410 411/*412 * intervals directory413 */414 415struct damon_sysfs_intervals {416	struct kobject kobj;417	unsigned long sample_us;418	unsigned long aggr_us;419	unsigned long update_us;420};421 422static struct damon_sysfs_intervals *damon_sysfs_intervals_alloc(423		unsigned long sample_us, unsigned long aggr_us,424		unsigned long update_us)425{426	struct damon_sysfs_intervals *intervals = kmalloc(sizeof(*intervals),427			GFP_KERNEL);428 429	if (!intervals)430		return NULL;431 432	intervals->kobj = (struct kobject){};433	intervals->sample_us = sample_us;434	intervals->aggr_us = aggr_us;435	intervals->update_us = update_us;436	return intervals;437}438 439static ssize_t sample_us_show(struct kobject *kobj,440		struct kobj_attribute *attr, char *buf)441{442	struct damon_sysfs_intervals *intervals = container_of(kobj,443			struct damon_sysfs_intervals, kobj);444 445	return sysfs_emit(buf, "%lu\n", intervals->sample_us);446}447 448static ssize_t sample_us_store(struct kobject *kobj,449		struct kobj_attribute *attr, const char *buf, size_t count)450{451	struct damon_sysfs_intervals *intervals = container_of(kobj,452			struct damon_sysfs_intervals, kobj);453	unsigned long us;454	int err = kstrtoul(buf, 0, &us);455 456	if (err)457		return err;458 459	intervals->sample_us = us;460	return count;461}462 463static ssize_t aggr_us_show(struct kobject *kobj, struct kobj_attribute *attr,464		char *buf)465{466	struct damon_sysfs_intervals *intervals = container_of(kobj,467			struct damon_sysfs_intervals, kobj);468 469	return sysfs_emit(buf, "%lu\n", intervals->aggr_us);470}471 472static ssize_t aggr_us_store(struct kobject *kobj, struct kobj_attribute *attr,473		const char *buf, size_t count)474{475	struct damon_sysfs_intervals *intervals = container_of(kobj,476			struct damon_sysfs_intervals, kobj);477	unsigned long us;478	int err = kstrtoul(buf, 0, &us);479 480	if (err)481		return err;482 483	intervals->aggr_us = us;484	return count;485}486 487static ssize_t update_us_show(struct kobject *kobj,488		struct kobj_attribute *attr, char *buf)489{490	struct damon_sysfs_intervals *intervals = container_of(kobj,491			struct damon_sysfs_intervals, kobj);492 493	return sysfs_emit(buf, "%lu\n", intervals->update_us);494}495 496static ssize_t update_us_store(struct kobject *kobj,497		struct kobj_attribute *attr, const char *buf, size_t count)498{499	struct damon_sysfs_intervals *intervals = container_of(kobj,500			struct damon_sysfs_intervals, kobj);501	unsigned long us;502	int err = kstrtoul(buf, 0, &us);503 504	if (err)505		return err;506 507	intervals->update_us = us;508	return count;509}510 511static void damon_sysfs_intervals_release(struct kobject *kobj)512{513	kfree(container_of(kobj, struct damon_sysfs_intervals, kobj));514}515 516static struct kobj_attribute damon_sysfs_intervals_sample_us_attr =517		__ATTR_RW_MODE(sample_us, 0600);518 519static struct kobj_attribute damon_sysfs_intervals_aggr_us_attr =520		__ATTR_RW_MODE(aggr_us, 0600);521 522static struct kobj_attribute damon_sysfs_intervals_update_us_attr =523		__ATTR_RW_MODE(update_us, 0600);524 525static struct attribute *damon_sysfs_intervals_attrs[] = {526	&damon_sysfs_intervals_sample_us_attr.attr,527	&damon_sysfs_intervals_aggr_us_attr.attr,528	&damon_sysfs_intervals_update_us_attr.attr,529	NULL,530};531ATTRIBUTE_GROUPS(damon_sysfs_intervals);532 533static const struct kobj_type damon_sysfs_intervals_ktype = {534	.release = damon_sysfs_intervals_release,535	.sysfs_ops = &kobj_sysfs_ops,536	.default_groups = damon_sysfs_intervals_groups,537};538 539/*540 * monitoring_attrs directory541 */542 543struct damon_sysfs_attrs {544	struct kobject kobj;545	struct damon_sysfs_intervals *intervals;546	struct damon_sysfs_ul_range *nr_regions_range;547};548 549static struct damon_sysfs_attrs *damon_sysfs_attrs_alloc(void)550{551	struct damon_sysfs_attrs *attrs = kmalloc(sizeof(*attrs), GFP_KERNEL);552 553	if (!attrs)554		return NULL;555	attrs->kobj = (struct kobject){};556	return attrs;557}558 559static int damon_sysfs_attrs_add_dirs(struct damon_sysfs_attrs *attrs)560{561	struct damon_sysfs_intervals *intervals;562	struct damon_sysfs_ul_range *nr_regions_range;563	int err;564 565	intervals = damon_sysfs_intervals_alloc(5000, 100000, 60000000);566	if (!intervals)567		return -ENOMEM;568 569	err = kobject_init_and_add(&intervals->kobj,570			&damon_sysfs_intervals_ktype, &attrs->kobj,571			"intervals");572	if (err)573		goto put_intervals_out;574	attrs->intervals = intervals;575 576	nr_regions_range = damon_sysfs_ul_range_alloc(10, 1000);577	if (!nr_regions_range) {578		err = -ENOMEM;579		goto put_intervals_out;580	}581 582	err = kobject_init_and_add(&nr_regions_range->kobj,583			&damon_sysfs_ul_range_ktype, &attrs->kobj,584			"nr_regions");585	if (err)586		goto put_nr_regions_intervals_out;587	attrs->nr_regions_range = nr_regions_range;588	return 0;589 590put_nr_regions_intervals_out:591	kobject_put(&nr_regions_range->kobj);592	attrs->nr_regions_range = NULL;593put_intervals_out:594	kobject_put(&intervals->kobj);595	attrs->intervals = NULL;596	return err;597}598 599static void damon_sysfs_attrs_rm_dirs(struct damon_sysfs_attrs *attrs)600{601	kobject_put(&attrs->nr_regions_range->kobj);602	kobject_put(&attrs->intervals->kobj);603}604 605static void damon_sysfs_attrs_release(struct kobject *kobj)606{607	kfree(container_of(kobj, struct damon_sysfs_attrs, kobj));608}609 610static struct attribute *damon_sysfs_attrs_attrs[] = {611	NULL,612};613ATTRIBUTE_GROUPS(damon_sysfs_attrs);614 615static const struct kobj_type damon_sysfs_attrs_ktype = {616	.release = damon_sysfs_attrs_release,617	.sysfs_ops = &kobj_sysfs_ops,618	.default_groups = damon_sysfs_attrs_groups,619};620 621/*622 * context directory623 */624 625/* This should match with enum damon_ops_id */626static const char * const damon_sysfs_ops_strs[] = {627	"vaddr",628	"fvaddr",629	"paddr",630};631 632struct damon_sysfs_context {633	struct kobject kobj;634	enum damon_ops_id ops_id;635	struct damon_sysfs_attrs *attrs;636	struct damon_sysfs_targets *targets;637	struct damon_sysfs_schemes *schemes;638};639 640static struct damon_sysfs_context *damon_sysfs_context_alloc(641		enum damon_ops_id ops_id)642{643	struct damon_sysfs_context *context = kmalloc(sizeof(*context),644				GFP_KERNEL);645 646	if (!context)647		return NULL;648	context->kobj = (struct kobject){};649	context->ops_id = ops_id;650	return context;651}652 653static int damon_sysfs_context_set_attrs(struct damon_sysfs_context *context)654{655	struct damon_sysfs_attrs *attrs = damon_sysfs_attrs_alloc();656	int err;657 658	if (!attrs)659		return -ENOMEM;660	err = kobject_init_and_add(&attrs->kobj, &damon_sysfs_attrs_ktype,661			&context->kobj, "monitoring_attrs");662	if (err)663		goto out;664	err = damon_sysfs_attrs_add_dirs(attrs);665	if (err)666		goto out;667	context->attrs = attrs;668	return 0;669 670out:671	kobject_put(&attrs->kobj);672	return err;673}674 675static int damon_sysfs_context_set_targets(struct damon_sysfs_context *context)676{677	struct damon_sysfs_targets *targets = damon_sysfs_targets_alloc();678	int err;679 680	if (!targets)681		return -ENOMEM;682	err = kobject_init_and_add(&targets->kobj, &damon_sysfs_targets_ktype,683			&context->kobj, "targets");684	if (err) {685		kobject_put(&targets->kobj);686		return err;687	}688	context->targets = targets;689	return 0;690}691 692static int damon_sysfs_context_set_schemes(struct damon_sysfs_context *context)693{694	struct damon_sysfs_schemes *schemes = damon_sysfs_schemes_alloc();695	int err;696 697	if (!schemes)698		return -ENOMEM;699	err = kobject_init_and_add(&schemes->kobj, &damon_sysfs_schemes_ktype,700			&context->kobj, "schemes");701	if (err) {702		kobject_put(&schemes->kobj);703		return err;704	}705	context->schemes = schemes;706	return 0;707}708 709static int damon_sysfs_context_add_dirs(struct damon_sysfs_context *context)710{711	int err;712 713	err = damon_sysfs_context_set_attrs(context);714	if (err)715		return err;716 717	err = damon_sysfs_context_set_targets(context);718	if (err)719		goto put_attrs_out;720 721	err = damon_sysfs_context_set_schemes(context);722	if (err)723		goto put_targets_attrs_out;724	return 0;725 726put_targets_attrs_out:727	kobject_put(&context->targets->kobj);728	context->targets = NULL;729put_attrs_out:730	kobject_put(&context->attrs->kobj);731	context->attrs = NULL;732	return err;733}734 735static void damon_sysfs_context_rm_dirs(struct damon_sysfs_context *context)736{737	damon_sysfs_attrs_rm_dirs(context->attrs);738	kobject_put(&context->attrs->kobj);739	damon_sysfs_targets_rm_dirs(context->targets);740	kobject_put(&context->targets->kobj);741	damon_sysfs_schemes_rm_dirs(context->schemes);742	kobject_put(&context->schemes->kobj);743}744 745static ssize_t avail_operations_show(struct kobject *kobj,746		struct kobj_attribute *attr, char *buf)747{748	enum damon_ops_id id;749	int len = 0;750 751	for (id = 0; id < NR_DAMON_OPS; id++) {752		if (!damon_is_registered_ops(id))753			continue;754		len += sysfs_emit_at(buf, len, "%s\n",755				damon_sysfs_ops_strs[id]);756	}757	return len;758}759 760static ssize_t operations_show(struct kobject *kobj,761		struct kobj_attribute *attr, char *buf)762{763	struct damon_sysfs_context *context = container_of(kobj,764			struct damon_sysfs_context, kobj);765 766	return sysfs_emit(buf, "%s\n", damon_sysfs_ops_strs[context->ops_id]);767}768 769static ssize_t operations_store(struct kobject *kobj,770		struct kobj_attribute *attr, const char *buf, size_t count)771{772	struct damon_sysfs_context *context = container_of(kobj,773			struct damon_sysfs_context, kobj);774	enum damon_ops_id id;775 776	for (id = 0; id < NR_DAMON_OPS; id++) {777		if (sysfs_streq(buf, damon_sysfs_ops_strs[id])) {778			context->ops_id = id;779			return count;780		}781	}782	return -EINVAL;783}784 785static void damon_sysfs_context_release(struct kobject *kobj)786{787	kfree(container_of(kobj, struct damon_sysfs_context, kobj));788}789 790static struct kobj_attribute damon_sysfs_context_avail_operations_attr =791		__ATTR_RO_MODE(avail_operations, 0400);792 793static struct kobj_attribute damon_sysfs_context_operations_attr =794		__ATTR_RW_MODE(operations, 0600);795 796static struct attribute *damon_sysfs_context_attrs[] = {797	&damon_sysfs_context_avail_operations_attr.attr,798	&damon_sysfs_context_operations_attr.attr,799	NULL,800};801ATTRIBUTE_GROUPS(damon_sysfs_context);802 803static const struct kobj_type damon_sysfs_context_ktype = {804	.release = damon_sysfs_context_release,805	.sysfs_ops = &kobj_sysfs_ops,806	.default_groups = damon_sysfs_context_groups,807};808 809/*810 * contexts directory811 */812 813struct damon_sysfs_contexts {814	struct kobject kobj;815	struct damon_sysfs_context **contexts_arr;816	int nr;817};818 819static struct damon_sysfs_contexts *damon_sysfs_contexts_alloc(void)820{821	return kzalloc(sizeof(struct damon_sysfs_contexts), GFP_KERNEL);822}823 824static void damon_sysfs_contexts_rm_dirs(struct damon_sysfs_contexts *contexts)825{826	struct damon_sysfs_context **contexts_arr = contexts->contexts_arr;827	int i;828 829	for (i = 0; i < contexts->nr; i++) {830		damon_sysfs_context_rm_dirs(contexts_arr[i]);831		kobject_put(&contexts_arr[i]->kobj);832	}833	contexts->nr = 0;834	kfree(contexts_arr);835	contexts->contexts_arr = NULL;836}837 838static int damon_sysfs_contexts_add_dirs(struct damon_sysfs_contexts *contexts,839		int nr_contexts)840{841	struct damon_sysfs_context **contexts_arr, *context;842	int err, i;843 844	damon_sysfs_contexts_rm_dirs(contexts);845	if (!nr_contexts)846		return 0;847 848	contexts_arr = kmalloc_array(nr_contexts, sizeof(*contexts_arr),849			GFP_KERNEL | __GFP_NOWARN);850	if (!contexts_arr)851		return -ENOMEM;852	contexts->contexts_arr = contexts_arr;853 854	for (i = 0; i < nr_contexts; i++) {855		context = damon_sysfs_context_alloc(DAMON_OPS_VADDR);856		if (!context) {857			damon_sysfs_contexts_rm_dirs(contexts);858			return -ENOMEM;859		}860 861		err = kobject_init_and_add(&context->kobj,862				&damon_sysfs_context_ktype, &contexts->kobj,863				"%d", i);864		if (err)865			goto out;866 867		err = damon_sysfs_context_add_dirs(context);868		if (err)869			goto out;870 871		contexts_arr[i] = context;872		contexts->nr++;873	}874	return 0;875 876out:877	damon_sysfs_contexts_rm_dirs(contexts);878	kobject_put(&context->kobj);879	return err;880}881 882static ssize_t nr_contexts_show(struct kobject *kobj,883		struct kobj_attribute *attr, char *buf)884{885	struct damon_sysfs_contexts *contexts = container_of(kobj,886			struct damon_sysfs_contexts, kobj);887 888	return sysfs_emit(buf, "%d\n", contexts->nr);889}890 891static ssize_t nr_contexts_store(struct kobject *kobj,892		struct kobj_attribute *attr, const char *buf, size_t count)893{894	struct damon_sysfs_contexts *contexts;895	int nr, err;896 897	err = kstrtoint(buf, 0, &nr);898	if (err)899		return err;900	/* TODO: support multiple contexts per kdamond */901	if (nr < 0 || 1 < nr)902		return -EINVAL;903 904	contexts = container_of(kobj, struct damon_sysfs_contexts, kobj);905	if (!mutex_trylock(&damon_sysfs_lock))906		return -EBUSY;907	err = damon_sysfs_contexts_add_dirs(contexts, nr);908	mutex_unlock(&damon_sysfs_lock);909	if (err)910		return err;911 912	return count;913}914 915static void damon_sysfs_contexts_release(struct kobject *kobj)916{917	kfree(container_of(kobj, struct damon_sysfs_contexts, kobj));918}919 920static struct kobj_attribute damon_sysfs_contexts_nr_attr921		= __ATTR_RW_MODE(nr_contexts, 0600);922 923static struct attribute *damon_sysfs_contexts_attrs[] = {924	&damon_sysfs_contexts_nr_attr.attr,925	NULL,926};927ATTRIBUTE_GROUPS(damon_sysfs_contexts);928 929static const struct kobj_type damon_sysfs_contexts_ktype = {930	.release = damon_sysfs_contexts_release,931	.sysfs_ops = &kobj_sysfs_ops,932	.default_groups = damon_sysfs_contexts_groups,933};934 935/*936 * kdamond directory937 */938 939struct damon_sysfs_kdamond {940	struct kobject kobj;941	struct damon_sysfs_contexts *contexts;942	struct damon_ctx *damon_ctx;943};944 945static struct damon_sysfs_kdamond *damon_sysfs_kdamond_alloc(void)946{947	return kzalloc(sizeof(struct damon_sysfs_kdamond), GFP_KERNEL);948}949 950static int damon_sysfs_kdamond_add_dirs(struct damon_sysfs_kdamond *kdamond)951{952	struct damon_sysfs_contexts *contexts;953	int err;954 955	contexts = damon_sysfs_contexts_alloc();956	if (!contexts)957		return -ENOMEM;958 959	err = kobject_init_and_add(&contexts->kobj,960			&damon_sysfs_contexts_ktype, &kdamond->kobj,961			"contexts");962	if (err) {963		kobject_put(&contexts->kobj);964		return err;965	}966	kdamond->contexts = contexts;967 968	return err;969}970 971static void damon_sysfs_kdamond_rm_dirs(struct damon_sysfs_kdamond *kdamond)972{973	damon_sysfs_contexts_rm_dirs(kdamond->contexts);974	kobject_put(&kdamond->contexts->kobj);975}976 977static bool damon_sysfs_ctx_running(struct damon_ctx *ctx)978{979	bool running;980 981	mutex_lock(&ctx->kdamond_lock);982	running = ctx->kdamond != NULL;983	mutex_unlock(&ctx->kdamond_lock);984	return running;985}986 987/*988 * enum damon_sysfs_cmd - Commands for a specific kdamond.989 */990enum damon_sysfs_cmd {991	/* @DAMON_SYSFS_CMD_ON: Turn the kdamond on. */992	DAMON_SYSFS_CMD_ON,993	/* @DAMON_SYSFS_CMD_OFF: Turn the kdamond off. */994	DAMON_SYSFS_CMD_OFF,995	/* @DAMON_SYSFS_CMD_COMMIT: Update kdamond inputs. */996	DAMON_SYSFS_CMD_COMMIT,997	/*998	 * @DAMON_SYSFS_CMD_COMMIT_SCHEMES_QUOTA_GOALS: Commit the quota goals999	 * to DAMON.1000	 */1001	DAMON_SYSFS_CMD_COMMIT_SCHEMES_QUOTA_GOALS,1002	/*1003	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS: Update scheme stats sysfs1004	 * files.1005	 */1006	DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS,1007	/*1008	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES: Update1009	 * tried_regions/total_bytes sysfs files for each scheme.1010	 */1011	DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES,1012	/*1013	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS: Update schemes tried1014	 * regions1015	 */1016	DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS,1017	/*1018	 * @DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS: Clear schemes tried1019	 * regions1020	 */1021	DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS,1022	/*1023	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS: Update the1024	 * effective size quota of the scheme in bytes.1025	 */1026	DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS,1027	/*1028	 * @NR_DAMON_SYSFS_CMDS: Total number of DAMON sysfs commands.1029	 */1030	NR_DAMON_SYSFS_CMDS,1031};1032 1033/* Should match with enum damon_sysfs_cmd */1034static const char * const damon_sysfs_cmd_strs[] = {1035	"on",1036	"off",1037	"commit",1038	"commit_schemes_quota_goals",1039	"update_schemes_stats",1040	"update_schemes_tried_bytes",1041	"update_schemes_tried_regions",1042	"clear_schemes_tried_regions",1043	"update_schemes_effective_quotas",1044};1045 1046/*1047 * struct damon_sysfs_cmd_request - A request to the DAMON callback.1048 * @cmd:	The command that needs to be handled by the callback.1049 * @kdamond:	The kobject wrapper that associated to the kdamond thread.1050 *1051 * This structure represents a sysfs command request that need to access some1052 * DAMON context-internal data.  Because DAMON context-internal data can be1053 * safely accessed from DAMON callbacks without additional synchronization, the1054 * request will be handled by the DAMON callback.  None-``NULL`` @kdamond means1055 * the request is valid.1056 */1057struct damon_sysfs_cmd_request {1058	enum damon_sysfs_cmd cmd;1059	struct damon_sysfs_kdamond *kdamond;1060};1061 1062/* Current DAMON callback request.  Protected by damon_sysfs_lock. */1063static struct damon_sysfs_cmd_request damon_sysfs_cmd_request;1064 1065static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,1066		char *buf)1067{1068	struct damon_sysfs_kdamond *kdamond = container_of(kobj,1069			struct damon_sysfs_kdamond, kobj);1070	struct damon_ctx *ctx = kdamond->damon_ctx;1071	bool running;1072 1073	if (!ctx)1074		running = false;1075	else1076		running = damon_sysfs_ctx_running(ctx);1077 1078	return sysfs_emit(buf, "%s\n", running ?1079			damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_ON] :1080			damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_OFF]);1081}1082 1083static int damon_sysfs_set_attrs(struct damon_ctx *ctx,1084		struct damon_sysfs_attrs *sys_attrs)1085{1086	struct damon_sysfs_intervals *sys_intervals = sys_attrs->intervals;1087	struct damon_sysfs_ul_range *sys_nr_regions =1088		sys_attrs->nr_regions_range;1089	struct damon_attrs attrs = {1090		.sample_interval = sys_intervals->sample_us,1091		.aggr_interval = sys_intervals->aggr_us,1092		.ops_update_interval = sys_intervals->update_us,1093		.min_nr_regions = sys_nr_regions->min,1094		.max_nr_regions = sys_nr_regions->max,1095	};1096	return damon_set_attrs(ctx, &attrs);1097}1098 1099static void damon_sysfs_destroy_targets(struct damon_ctx *ctx)1100{1101	struct damon_target *t, *next;1102	bool has_pid = damon_target_has_pid(ctx);1103 1104	damon_for_each_target_safe(t, next, ctx) {1105		if (has_pid)1106			put_pid(t->pid);1107		damon_destroy_target(t);1108	}1109}1110 1111static int damon_sysfs_set_regions(struct damon_target *t,1112		struct damon_sysfs_regions *sysfs_regions)1113{1114	struct damon_addr_range *ranges = kmalloc_array(sysfs_regions->nr,1115			sizeof(*ranges), GFP_KERNEL | __GFP_NOWARN);1116	int i, err = -EINVAL;1117 1118	if (!ranges)1119		return -ENOMEM;1120	for (i = 0; i < sysfs_regions->nr; i++) {1121		struct damon_sysfs_region *sys_region =1122			sysfs_regions->regions_arr[i];1123 1124		if (sys_region->ar.start > sys_region->ar.end)1125			goto out;1126 1127		ranges[i].start = sys_region->ar.start;1128		ranges[i].end = sys_region->ar.end;1129		if (i == 0)1130			continue;1131		if (ranges[i - 1].end > ranges[i].start)1132			goto out;1133	}1134	err = damon_set_regions(t, ranges, sysfs_regions->nr);1135out:1136	kfree(ranges);1137	return err;1138 1139}1140 1141static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target,1142		struct damon_ctx *ctx)1143{1144	struct damon_target *t = damon_new_target();1145	int err = -EINVAL;1146 1147	if (!t)1148		return -ENOMEM;1149	damon_add_target(ctx, t);1150	if (damon_target_has_pid(ctx)) {1151		t->pid = find_get_pid(sys_target->pid);1152		if (!t->pid)1153			goto destroy_targets_out;1154	}1155	err = damon_sysfs_set_regions(t, sys_target->regions);1156	if (err)1157		goto destroy_targets_out;1158	return 0;1159 1160destroy_targets_out:1161	damon_sysfs_destroy_targets(ctx);1162	return err;1163}1164 1165static int damon_sysfs_add_targets(struct damon_ctx *ctx,1166		struct damon_sysfs_targets *sysfs_targets)1167{1168	int i, err;1169 1170	/* Multiple physical address space monitoring targets makes no sense */1171	if (ctx->ops.id == DAMON_OPS_PADDR && sysfs_targets->nr > 1)1172		return -EINVAL;1173 1174	for (i = 0; i < sysfs_targets->nr; i++) {1175		struct damon_sysfs_target *st = sysfs_targets->targets_arr[i];1176 1177		err = damon_sysfs_add_target(st, ctx);1178		if (err)1179			return err;1180	}1181	return 0;1182}1183 1184static bool damon_sysfs_schemes_regions_updating;1185 1186static void damon_sysfs_before_terminate(struct damon_ctx *ctx)1187{1188	struct damon_target *t, *next;1189	struct damon_sysfs_kdamond *kdamond;1190	enum damon_sysfs_cmd cmd;1191 1192	/* damon_sysfs_schemes_update_regions_stop() might not yet called */1193	kdamond = damon_sysfs_cmd_request.kdamond;1194	cmd = damon_sysfs_cmd_request.cmd;1195	if (kdamond && ctx == kdamond->damon_ctx &&1196			(cmd == DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS ||1197			 cmd == DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES) &&1198			damon_sysfs_schemes_regions_updating) {1199		damon_sysfs_schemes_update_regions_stop(ctx);1200		damon_sysfs_schemes_regions_updating = false;1201		mutex_unlock(&damon_sysfs_lock);1202	}1203 1204	if (!damon_target_has_pid(ctx))1205		return;1206 1207	mutex_lock(&ctx->kdamond_lock);1208	damon_for_each_target_safe(t, next, ctx) {1209		put_pid(t->pid);1210		damon_destroy_target(t);1211	}1212	mutex_unlock(&ctx->kdamond_lock);1213}1214 1215/*1216 * damon_sysfs_upd_schemes_stats() - Update schemes stats sysfs files.1217 * @kdamond:	The kobject wrapper that associated to the kdamond thread.1218 *1219 * This function reads the schemes stats of specific kdamond and update the1220 * related values for sysfs files.  This function should be called from DAMON1221 * callbacks while holding ``damon_syfs_lock``, to safely access the DAMON1222 * contexts-internal data and DAMON sysfs variables.1223 */1224static int damon_sysfs_upd_schemes_stats(struct damon_sysfs_kdamond *kdamond)1225{1226	struct damon_ctx *ctx = kdamond->damon_ctx;1227 1228	if (!ctx)1229		return -EINVAL;1230	damon_sysfs_schemes_update_stats(1231			kdamond->contexts->contexts_arr[0]->schemes, ctx);1232	return 0;1233}1234 1235static int damon_sysfs_upd_schemes_regions_start(1236		struct damon_sysfs_kdamond *kdamond, bool total_bytes_only)1237{1238	struct damon_ctx *ctx = kdamond->damon_ctx;1239 1240	if (!ctx)1241		return -EINVAL;1242	return damon_sysfs_schemes_update_regions_start(1243			kdamond->contexts->contexts_arr[0]->schemes, ctx,1244			total_bytes_only);1245}1246 1247static int damon_sysfs_upd_schemes_regions_stop(1248		struct damon_sysfs_kdamond *kdamond)1249{1250	struct damon_ctx *ctx = kdamond->damon_ctx;1251 1252	if (!ctx)1253		return -EINVAL;1254	return damon_sysfs_schemes_update_regions_stop(ctx);1255}1256 1257static int damon_sysfs_clear_schemes_regions(1258		struct damon_sysfs_kdamond *kdamond)1259{1260	struct damon_ctx *ctx = kdamond->damon_ctx;1261 1262	if (!ctx)1263		return -EINVAL;1264	return damon_sysfs_schemes_clear_regions(1265			kdamond->contexts->contexts_arr[0]->schemes, ctx);1266}1267 1268static inline bool damon_sysfs_kdamond_running(1269		struct damon_sysfs_kdamond *kdamond)1270{1271	return kdamond->damon_ctx &&1272		damon_sysfs_ctx_running(kdamond->damon_ctx);1273}1274 1275static int damon_sysfs_apply_inputs(struct damon_ctx *ctx,1276		struct damon_sysfs_context *sys_ctx)1277{1278	int err;1279 1280	err = damon_select_ops(ctx, sys_ctx->ops_id);1281	if (err)1282		return err;1283	err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs);1284	if (err)1285		return err;1286	err = damon_sysfs_add_targets(ctx, sys_ctx->targets);1287	if (err)1288		return err;1289	return damon_sysfs_add_schemes(ctx, sys_ctx->schemes);1290}1291 1292static struct damon_ctx *damon_sysfs_build_ctx(1293		struct damon_sysfs_context *sys_ctx);1294 1295/*1296 * damon_sysfs_commit_input() - Commit user inputs to a running kdamond.1297 * @kdamond:	The kobject wrapper for the associated kdamond.1298 *1299 * If the sysfs input is wrong, the kdamond will be terminated.1300 */1301static int damon_sysfs_commit_input(struct damon_sysfs_kdamond *kdamond)1302{1303	struct damon_ctx *param_ctx;1304	int err;1305 1306	if (!damon_sysfs_kdamond_running(kdamond))1307		return -EINVAL;1308	/* TODO: Support multiple contexts per kdamond */1309	if (kdamond->contexts->nr != 1)1310		return -EINVAL;1311 1312	param_ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);1313	if (IS_ERR(param_ctx))1314		return PTR_ERR(param_ctx);1315	err = damon_commit_ctx(kdamond->damon_ctx, param_ctx);1316	damon_sysfs_destroy_targets(param_ctx);1317	damon_destroy_ctx(param_ctx);1318	return err;1319}1320 1321static int damon_sysfs_commit_schemes_quota_goals(1322		struct damon_sysfs_kdamond *sysfs_kdamond)1323{1324	struct damon_ctx *ctx;1325	struct damon_sysfs_context *sysfs_ctx;1326 1327	if (!damon_sysfs_kdamond_running(sysfs_kdamond))1328		return -EINVAL;1329	/* TODO: Support multiple contexts per kdamond */1330	if (sysfs_kdamond->contexts->nr != 1)1331		return -EINVAL;1332 1333	ctx = sysfs_kdamond->damon_ctx;1334	sysfs_ctx = sysfs_kdamond->contexts->contexts_arr[0];1335	return damos_sysfs_set_quota_scores(sysfs_ctx->schemes, ctx);1336}1337 1338/*1339 * damon_sysfs_upd_schemes_effective_quotas() - Update schemes effective quotas1340 * sysfs files.1341 * @kdamond:	The kobject wrapper that associated to the kdamond thread.1342 *1343 * This function reads the schemes' effective quotas of specific kdamond and1344 * update the related values for sysfs files.  This function should be called1345 * from DAMON callbacks while holding ``damon_syfs_lock``, to safely access the1346 * DAMON contexts-internal data and DAMON sysfs variables.1347 */1348static int damon_sysfs_upd_schemes_effective_quotas(1349		struct damon_sysfs_kdamond *kdamond)1350{1351	struct damon_ctx *ctx = kdamond->damon_ctx;1352 1353	if (!ctx)1354		return -EINVAL;1355	damos_sysfs_update_effective_quotas(1356			kdamond->contexts->contexts_arr[0]->schemes, ctx);1357	return 0;1358}1359 1360 1361/*1362 * damon_sysfs_cmd_request_callback() - DAMON callback for handling requests.1363 * @c:		The DAMON context of the callback.1364 * @active:	Whether @c is not deactivated due to watermarks.1365 * @after_aggr:	Whether this is called from after_aggregation() callback.1366 *1367 * This function is periodically called back from the kdamond thread for @c.1368 * Then, it checks if there is a waiting DAMON sysfs request and handles it.1369 */1370static int damon_sysfs_cmd_request_callback(struct damon_ctx *c, bool active,1371		bool after_aggregation)1372{1373	struct damon_sysfs_kdamond *kdamond;1374	bool total_bytes_only = false;1375	int err = 0;1376 1377	/* avoid deadlock due to concurrent state_store('off') */1378	if (!damon_sysfs_schemes_regions_updating &&1379			!mutex_trylock(&damon_sysfs_lock))1380		return 0;1381	kdamond = damon_sysfs_cmd_request.kdamond;1382	if (!kdamond || kdamond->damon_ctx != c)1383		goto out;1384	switch (damon_sysfs_cmd_request.cmd) {1385	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS:1386		err = damon_sysfs_upd_schemes_stats(kdamond);1387		break;1388	case DAMON_SYSFS_CMD_COMMIT:1389		if (!after_aggregation)1390			goto out;1391		err = damon_sysfs_commit_input(kdamond);1392		break;1393	case DAMON_SYSFS_CMD_COMMIT_SCHEMES_QUOTA_GOALS:1394		err = damon_sysfs_commit_schemes_quota_goals(kdamond);1395		break;1396	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES:1397		total_bytes_only = true;1398		fallthrough;1399	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS:1400		if (!damon_sysfs_schemes_regions_updating) {1401			err = damon_sysfs_upd_schemes_regions_start(kdamond,1402					total_bytes_only);1403			if (!err) {1404				damon_sysfs_schemes_regions_updating = true;1405				goto keep_lock_out;1406			}1407		} else {1408			damos_sysfs_mark_finished_regions_updates(c);1409			/*1410			 * Continue regions updating if DAMON is till1411			 * active and the update for all schemes is not1412			 * finished.1413			 */1414			if (active && !damos_sysfs_regions_upd_done())1415				goto keep_lock_out;1416			err = damon_sysfs_upd_schemes_regions_stop(kdamond);1417			damon_sysfs_schemes_regions_updating = false;1418		}1419		break;1420	case DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS:1421		err = damon_sysfs_clear_schemes_regions(kdamond);1422		break;1423	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS:1424		err = damon_sysfs_upd_schemes_effective_quotas(kdamond);1425		break;1426	default:1427		break;1428	}1429	/* Mark the request as invalid now. */1430	damon_sysfs_cmd_request.kdamond = NULL;1431out:1432	if (!damon_sysfs_schemes_regions_updating)1433		mutex_unlock(&damon_sysfs_lock);1434keep_lock_out:1435	return err;1436}1437 1438static int damon_sysfs_after_wmarks_check(struct damon_ctx *c)1439{1440	/*1441	 * after_wmarks_check() is called back while the context is deactivated1442	 * by watermarks.1443	 */1444	return damon_sysfs_cmd_request_callback(c, false, false);1445}1446 1447static int damon_sysfs_after_sampling(struct damon_ctx *c)1448{1449	/*1450	 * after_sampling() is called back only while the context is not1451	 * deactivated by watermarks.1452	 */1453	return damon_sysfs_cmd_request_callback(c, true, false);1454}1455 1456static int damon_sysfs_after_aggregation(struct damon_ctx *c)1457{1458	/*1459	 * after_aggregation() is called back only while the context is not1460	 * deactivated by watermarks.1461	 */1462	return damon_sysfs_cmd_request_callback(c, true, true);1463}1464 1465static struct damon_ctx *damon_sysfs_build_ctx(1466		struct damon_sysfs_context *sys_ctx)1467{1468	struct damon_ctx *ctx = damon_new_ctx();1469	int err;1470 1471	if (!ctx)1472		return ERR_PTR(-ENOMEM);1473 1474	err = damon_sysfs_apply_inputs(ctx, sys_ctx);1475	if (err) {1476		damon_destroy_ctx(ctx);1477		return ERR_PTR(err);1478	}1479 1480	ctx->callback.after_wmarks_check = damon_sysfs_after_wmarks_check;1481	ctx->callback.after_sampling = damon_sysfs_after_sampling;1482	ctx->callback.after_aggregation = damon_sysfs_after_aggregation;1483	ctx->callback.before_terminate = damon_sysfs_before_terminate;1484	return ctx;1485}1486 1487static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond)1488{1489	struct damon_ctx *ctx;1490	int err;1491 1492	if (damon_sysfs_kdamond_running(kdamond))1493		return -EBUSY;1494	if (damon_sysfs_cmd_request.kdamond == kdamond)1495		return -EBUSY;1496	/* TODO: support multiple contexts per kdamond */1497	if (kdamond->contexts->nr != 1)1498		return -EINVAL;1499 1500	if (kdamond->damon_ctx)1501		damon_destroy_ctx(kdamond->damon_ctx);1502	kdamond->damon_ctx = NULL;1503 1504	ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);1505	if (IS_ERR(ctx))1506		return PTR_ERR(ctx);1507	err = damon_start(&ctx, 1, false);1508	if (err) {1509		damon_destroy_ctx(ctx);1510		return err;1511	}1512	kdamond->damon_ctx = ctx;1513	return err;1514}1515 1516static int damon_sysfs_turn_damon_off(struct damon_sysfs_kdamond *kdamond)1517{1518	if (!kdamond->damon_ctx)1519		return -EINVAL;1520	return damon_stop(&kdamond->damon_ctx, 1);1521	/*1522	 * To allow users show final monitoring results of already turned-off1523	 * DAMON, we free kdamond->damon_ctx in next1524	 * damon_sysfs_turn_damon_on(), or kdamonds_nr_store()1525	 */1526}1527 1528/*1529 * damon_sysfs_handle_cmd() - Handle a command for a specific kdamond.1530 * @cmd:	The command to handle.1531 * @kdamond:	The kobject wrapper for the associated kdamond.1532 *1533 * This function handles a DAMON sysfs command for a kdamond.  For commands1534 * that need to access running DAMON context-internal data, it requests1535 * handling of the command to the DAMON callback1536 * (@damon_sysfs_cmd_request_callback()) and wait until it is properly handled,1537 * or the context is completed.1538 *1539 * Return: 0 on success, negative error code otherwise.1540 */1541static int damon_sysfs_handle_cmd(enum damon_sysfs_cmd cmd,1542		struct damon_sysfs_kdamond *kdamond)1543{1544	bool need_wait = true;1545 1546	/* Handle commands that doesn't access DAMON context-internal data */1547	switch (cmd) {1548	case DAMON_SYSFS_CMD_ON:1549		return damon_sysfs_turn_damon_on(kdamond);1550	case DAMON_SYSFS_CMD_OFF:1551		return damon_sysfs_turn_damon_off(kdamond);1552	default:1553		break;1554	}1555 1556	/* Pass the command to DAMON callback for safe DAMON context access */1557	if (damon_sysfs_cmd_request.kdamond)1558		return -EBUSY;1559	if (!damon_sysfs_kdamond_running(kdamond))1560		return -EINVAL;1561	damon_sysfs_cmd_request.cmd = cmd;1562	damon_sysfs_cmd_request.kdamond = kdamond;1563 1564	/*1565	 * wait until damon_sysfs_cmd_request_callback() handles the request1566	 * from kdamond context1567	 */1568	mutex_unlock(&damon_sysfs_lock);1569	while (need_wait) {1570		schedule_timeout_idle(msecs_to_jiffies(100));1571		if (!mutex_trylock(&damon_sysfs_lock))1572			continue;1573		if (!damon_sysfs_cmd_request.kdamond) {1574			/* damon_sysfs_cmd_request_callback() handled */1575			need_wait = false;1576		} else if (!damon_sysfs_kdamond_running(kdamond)) {1577			/* kdamond has already finished */1578			need_wait = false;1579			damon_sysfs_cmd_request.kdamond = NULL;1580		}1581		mutex_unlock(&damon_sysfs_lock);1582	}1583	mutex_lock(&damon_sysfs_lock);1584	return 0;1585}1586 1587static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,1588		const char *buf, size_t count)1589{1590	struct damon_sysfs_kdamond *kdamond = container_of(kobj,1591			struct damon_sysfs_kdamond, kobj);1592	enum damon_sysfs_cmd cmd;1593	ssize_t ret = -EINVAL;1594 1595	if (!mutex_trylock(&damon_sysfs_lock))1596		return -EBUSY;1597	for (cmd = 0; cmd < NR_DAMON_SYSFS_CMDS; cmd++) {1598		if (sysfs_streq(buf, damon_sysfs_cmd_strs[cmd])) {1599			ret = damon_sysfs_handle_cmd(cmd, kdamond);1600			break;1601		}1602	}1603	mutex_unlock(&damon_sysfs_lock);1604	if (!ret)1605		ret = count;1606	return ret;1607}1608 1609static ssize_t pid_show(struct kobject *kobj,1610		struct kobj_attribute *attr, char *buf)1611{1612	struct damon_sysfs_kdamond *kdamond = container_of(kobj,1613			struct damon_sysfs_kdamond, kobj);1614	struct damon_ctx *ctx;1615	int pid = -1;1616 1617	if (!mutex_trylock(&damon_sysfs_lock))1618		return -EBUSY;1619	ctx = kdamond->damon_ctx;1620	if (!ctx)1621		goto out;1622 1623	mutex_lock(&ctx->kdamond_lock);1624	if (ctx->kdamond)1625		pid = ctx->kdamond->pid;1626	mutex_unlock(&ctx->kdamond_lock);1627out:1628	mutex_unlock(&damon_sysfs_lock);1629	return sysfs_emit(buf, "%d\n", pid);1630}1631 1632static void damon_sysfs_kdamond_release(struct kobject *kobj)1633{1634	struct damon_sysfs_kdamond *kdamond = container_of(kobj,1635			struct damon_sysfs_kdamond, kobj);1636 1637	if (kdamond->damon_ctx)1638		damon_destroy_ctx(kdamond->damon_ctx);1639	kfree(kdamond);1640}1641 1642static struct kobj_attribute damon_sysfs_kdamond_state_attr =1643		__ATTR_RW_MODE(state, 0600);1644 1645static struct kobj_attribute damon_sysfs_kdamond_pid_attr =1646		__ATTR_RO_MODE(pid, 0400);1647 1648static struct attribute *damon_sysfs_kdamond_attrs[] = {1649	&damon_sysfs_kdamond_state_attr.attr,1650	&damon_sysfs_kdamond_pid_attr.attr,1651	NULL,1652};1653ATTRIBUTE_GROUPS(damon_sysfs_kdamond);1654 1655static const struct kobj_type damon_sysfs_kdamond_ktype = {1656	.release = damon_sysfs_kdamond_release,1657	.sysfs_ops = &kobj_sysfs_ops,1658	.default_groups = damon_sysfs_kdamond_groups,1659};1660 1661/*1662 * kdamonds directory1663 */1664 1665struct damon_sysfs_kdamonds {1666	struct kobject kobj;1667	struct damon_sysfs_kdamond **kdamonds_arr;1668	int nr;1669};1670 1671static struct damon_sysfs_kdamonds *damon_sysfs_kdamonds_alloc(void)1672{1673	return kzalloc(sizeof(struct damon_sysfs_kdamonds), GFP_KERNEL);1674}1675 1676static void damon_sysfs_kdamonds_rm_dirs(struct damon_sysfs_kdamonds *kdamonds)1677{1678	struct damon_sysfs_kdamond **kdamonds_arr = kdamonds->kdamonds_arr;1679	int i;1680 1681	for (i = 0; i < kdamonds->nr; i++) {1682		damon_sysfs_kdamond_rm_dirs(kdamonds_arr[i]);1683		kobject_put(&kdamonds_arr[i]->kobj);1684	}1685	kdamonds->nr = 0;1686	kfree(kdamonds_arr);1687	kdamonds->kdamonds_arr = NULL;1688}1689 1690static bool damon_sysfs_kdamonds_busy(struct damon_sysfs_kdamond **kdamonds,1691		int nr_kdamonds)1692{1693	int i;1694 1695	for (i = 0; i < nr_kdamonds; i++) {1696		if (damon_sysfs_kdamond_running(kdamonds[i]) ||1697		    damon_sysfs_cmd_request.kdamond == kdamonds[i])1698			return true;1699	}1700 1701	return false;1702}1703 1704static int damon_sysfs_kdamonds_add_dirs(struct damon_sysfs_kdamonds *kdamonds,1705		int nr_kdamonds)1706{1707	struct damon_sysfs_kdamond **kdamonds_arr, *kdamond;1708	int err, i;1709 1710	if (damon_sysfs_kdamonds_busy(kdamonds->kdamonds_arr, kdamonds->nr))1711		return -EBUSY;1712 1713	damon_sysfs_kdamonds_rm_dirs(kdamonds);1714	if (!nr_kdamonds)1715		return 0;1716 1717	kdamonds_arr = kmalloc_array(nr_kdamonds, sizeof(*kdamonds_arr),1718			GFP_KERNEL | __GFP_NOWARN);1719	if (!kdamonds_arr)1720		return -ENOMEM;1721	kdamonds->kdamonds_arr = kdamonds_arr;1722 1723	for (i = 0; i < nr_kdamonds; i++) {1724		kdamond = damon_sysfs_kdamond_alloc();1725		if (!kdamond) {1726			damon_sysfs_kdamonds_rm_dirs(kdamonds);1727			return -ENOMEM;1728		}1729 1730		err = kobject_init_and_add(&kdamond->kobj,1731				&damon_sysfs_kdamond_ktype, &kdamonds->kobj,1732				"%d", i);1733		if (err)1734			goto out;1735 1736		err = damon_sysfs_kdamond_add_dirs(kdamond);1737		if (err)1738			goto out;1739 1740		kdamonds_arr[i] = kdamond;1741		kdamonds->nr++;1742	}1743	return 0;1744 1745out:1746	damon_sysfs_kdamonds_rm_dirs(kdamonds);1747	kobject_put(&kdamond->kobj);1748	return err;1749}1750 1751static ssize_t nr_kdamonds_show(struct kobject *kobj,1752		struct kobj_attribute *attr, char *buf)1753{1754	struct damon_sysfs_kdamonds *kdamonds = container_of(kobj,1755			struct damon_sysfs_kdamonds, kobj);1756 1757	return sysfs_emit(buf, "%d\n", kdamonds->nr);1758}1759 1760static ssize_t nr_kdamonds_store(struct kobject *kobj,1761		struct kobj_attribute *attr, const char *buf, size_t count)1762{1763	struct damon_sysfs_kdamonds *kdamonds;1764	int nr, err;1765 1766	err = kstrtoint(buf, 0, &nr);1767	if (err)1768		return err;1769	if (nr < 0)1770		return -EINVAL;1771 1772	kdamonds = container_of(kobj, struct damon_sysfs_kdamonds, kobj);1773 1774	if (!mutex_trylock(&damon_sysfs_lock))1775		return -EBUSY;1776	err = damon_sysfs_kdamonds_add_dirs(kdamonds, nr);1777	mutex_unlock(&damon_sysfs_lock);1778	if (err)1779		return err;1780 1781	return count;1782}1783 1784static void damon_sysfs_kdamonds_release(struct kobject *kobj)1785{1786	kfree(container_of(kobj, struct damon_sysfs_kdamonds, kobj));1787}1788 1789static struct kobj_attribute damon_sysfs_kdamonds_nr_attr =1790		__ATTR_RW_MODE(nr_kdamonds, 0600);1791 1792static struct attribute *damon_sysfs_kdamonds_attrs[] = {1793	&damon_sysfs_kdamonds_nr_attr.attr,1794	NULL,1795};1796ATTRIBUTE_GROUPS(damon_sysfs_kdamonds);1797 1798static const struct kobj_type damon_sysfs_kdamonds_ktype = {1799	.release = damon_sysfs_kdamonds_release,1800	.sysfs_ops = &kobj_sysfs_ops,1801	.default_groups = damon_sysfs_kdamonds_groups,1802};1803 1804/*1805 * damon user interface directory1806 */1807 1808struct damon_sysfs_ui_dir {1809	struct kobject kobj;1810	struct damon_sysfs_kdamonds *kdamonds;1811};1812 1813static struct damon_sysfs_ui_dir *damon_sysfs_ui_dir_alloc(void)1814{1815	return kzalloc(sizeof(struct damon_sysfs_ui_dir), GFP_KERNEL);1816}1817 1818static int damon_sysfs_ui_dir_add_dirs(struct damon_sysfs_ui_dir *ui_dir)1819{1820	struct damon_sysfs_kdamonds *kdamonds;1821	int err;1822 1823	kdamonds = damon_sysfs_kdamonds_alloc();1824	if (!kdamonds)1825		return -ENOMEM;1826 1827	err = kobject_init_and_add(&kdamonds->kobj,1828			&damon_sysfs_kdamonds_ktype, &ui_dir->kobj,1829			"kdamonds");1830	if (err) {1831		kobject_put(&kdamonds->kobj);1832		return err;1833	}1834	ui_dir->kdamonds = kdamonds;1835	return err;1836}1837 1838static void damon_sysfs_ui_dir_release(struct kobject *kobj)1839{1840	kfree(container_of(kobj, struct damon_sysfs_ui_dir, kobj));1841}1842 1843static struct attribute *damon_sysfs_ui_dir_attrs[] = {1844	NULL,1845};1846ATTRIBUTE_GROUPS(damon_sysfs_ui_dir);1847 1848static const struct kobj_type damon_sysfs_ui_dir_ktype = {1849	.release = damon_sysfs_ui_dir_release,1850	.sysfs_ops = &kobj_sysfs_ops,1851	.default_groups = damon_sysfs_ui_dir_groups,1852};1853 1854static int __init damon_sysfs_init(void)1855{1856	struct kobject *damon_sysfs_root;1857	struct damon_sysfs_ui_dir *admin;1858	int err;1859 1860	damon_sysfs_root = kobject_create_and_add("damon", mm_kobj);1861	if (!damon_sysfs_root)1862		return -ENOMEM;1863 1864	admin = damon_sysfs_ui_dir_alloc();1865	if (!admin) {1866		kobject_put(damon_sysfs_root);1867		return -ENOMEM;1868	}1869	err = kobject_init_and_add(&admin->kobj, &damon_sysfs_ui_dir_ktype,1870			damon_sysfs_root, "admin");1871	if (err)1872		goto out;1873	err = damon_sysfs_ui_dir_add_dirs(admin);1874	if (err)1875		goto out;1876	return 0;1877 1878out:1879	kobject_put(&admin->kobj);1880	kobject_put(damon_sysfs_root);1881	return err;1882}1883subsys_initcall(damon_sysfs_init);1884 1885#include "tests/sysfs-kunit.h"1886