1 // SPDX-License-Identifier: GPL-2.0
5  * Pseudo-locking support built on top of Cache Allocation Technology (CAT)
26 #include <asm/intel-family.h>
44  * pseudo-locked regions.
51  * get_prefetch_disable_bits - prefetch disable bits of supported platforms
55  * pseudo-locking. This includes testing to ensure pseudo-locked regions
57  * as well as that these pseudo-locked regions can maintain their low cache
60  * After a platform has been validated to support pseudo-locking its
106  * pseudo_lock_minor_get - Obtain available minor number
121 		return -ENOSPC;  in pseudo_lock_minor_get()
130  * pseudo_lock_minor_release - Return minor number to available
139  * region_find_by_minor - Locate a pseudo-lock region by inode minor number
140  * @minor: The minor number of the device representing pseudo-locked region
143  * pseudo-locked region it belongs to. This is done by matching the minor
144  * number of the device to the pseudo-locked region it belongs.
146  * Minor numbers are assigned at the time a pseudo-locked region is associated
149  * Return: On success return pointer to resource group owning the pseudo-locked
157 		if (rdtgrp->plr && rdtgrp->plr->minor == minor) {  in region_find_by_minor()
166  * struct pseudo_lock_pm_req - A power management QoS request list entry
167  * @list:	Entry within the @pm_reqs list for a pseudo-locked region
179 	list_for_each_entry_safe(pm_req, next, &plr->pm_reqs, list) {  in pseudo_lock_cstates_relax()
180 		dev_pm_qos_remove_request(&pm_req->req);  in pseudo_lock_cstates_relax()
181 		list_del(&pm_req->list);  in pseudo_lock_cstates_relax()
187  * pseudo_lock_cstates_constrain - Restrict cores from entering C6
188  * @plr: Pseudo-locked region
210 	for_each_cpu(cpu, &plr->d->cpu_mask) {  in pseudo_lock_cstates_constrain()
214 			ret = -ENOMEM;  in pseudo_lock_cstates_constrain()
218 					     &pm_req->req,  in pseudo_lock_cstates_constrain()
225 			ret = -1;  in pseudo_lock_cstates_constrain()
228 		list_add(&pm_req->list, &plr->pm_reqs);  in pseudo_lock_cstates_constrain()
239  * pseudo_lock_region_clear - Reset pseudo-lock region data
240  * @plr: pseudo-lock region
242  * All content of the pseudo-locked region is reset - any memory allocated
249 	plr->size = 0;  in pseudo_lock_region_clear()
250 	plr->line_size = 0;  in pseudo_lock_region_clear()
251 	kfree(plr->kmem);  in pseudo_lock_region_clear()
252 	plr->kmem = NULL;  in pseudo_lock_region_clear()
253 	plr->s = NULL;  in pseudo_lock_region_clear()
254 	if (plr->d)  in pseudo_lock_region_clear()
255 		plr->d->plr = NULL;  in pseudo_lock_region_clear()
256 	plr->d = NULL;  in pseudo_lock_region_clear()
257 	plr->cbm = 0;  in pseudo_lock_region_clear()
258 	plr->debugfs_dir = NULL;  in pseudo_lock_region_clear()
262  * pseudo_lock_region_init - Initialize pseudo-lock region information
263  * @plr: pseudo-lock region
265  * Called after user provided a schemata to be pseudo-locked. From the
268  * required for pseudo-locking is deduced from this data and &struct
270  * - size in bytes of the region to be pseudo-locked
271  * - cache line size to know the stride with which data needs to be accessed
272  *   to be pseudo-locked
273  * - a cpu associated with the cache instance on which the pseudo-locking
276  * Return: 0 on success, <0 on failure. Descriptive error will be written
286 	plr->cpu = cpumask_first(&plr->d->cpu_mask);  in pseudo_lock_region_init()
288 	if (!cpu_online(plr->cpu)) {  in pseudo_lock_region_init()
290 				    plr->cpu);  in pseudo_lock_region_init()
291 		ret = -ENODEV;  in pseudo_lock_region_init()
295 	ci = get_cpu_cacheinfo(plr->cpu);  in pseudo_lock_region_init()
297 	plr->size = rdtgroup_cbm_to_size(plr->s->res, plr->d, plr->cbm);  in pseudo_lock_region_init()
299 	for (i = 0; i < ci->num_leaves; i++) {  in pseudo_lock_region_init()
300 		if (ci->info_list[i].level == plr->s->res->cache_level) {  in pseudo_lock_region_init()
301 			plr->line_size = ci->info_list[i].coherency_line_size;  in pseudo_lock_region_init()
306 	ret = -1;  in pseudo_lock_region_init()
314  * pseudo_lock_init - Initialize a pseudo-lock region
315  * @rdtgrp: resource group to which new pseudo-locked region will belong
317  * A pseudo-locked region is associated with a resource group. When this
318  * association is created the pseudo-locked region is initialized. The
319  * details of the pseudo-locked region are not known at this time so only
330 		return -ENOMEM;  in pseudo_lock_init()
332 	init_waitqueue_head(&plr->lock_thread_wq);  in pseudo_lock_init()
333 	INIT_LIST_HEAD(&plr->pm_reqs);  in pseudo_lock_init()
334 	rdtgrp->plr = plr;  in pseudo_lock_init()
339  * pseudo_lock_region_alloc - Allocate kernel memory that will be pseudo-locked
340  * @plr: pseudo-lock region
342  * Initialize the details required to set up the pseudo-locked region and
343  * allocate the contiguous memory that will be pseudo-locked to the cache.
345  * Return: 0 on success, <0 on failure.  Descriptive error will be written
360 	if (plr->size > KMALLOC_MAX_SIZE) {  in pseudo_lock_region_alloc()
362 		ret = -E2BIG;  in pseudo_lock_region_alloc()
366 	plr->kmem = kzalloc(plr->size, GFP_KERNEL);  in pseudo_lock_region_alloc()
367 	if (!plr->kmem) {  in pseudo_lock_region_alloc()
369 		ret = -ENOMEM;  in pseudo_lock_region_alloc()
382  * pseudo_lock_free - Free a pseudo-locked region
383  * @rdtgrp: resource group to which pseudo-locked region belonged
385  * The pseudo-locked region's resources have already been released, or not
393 	pseudo_lock_region_clear(rdtgrp->plr);  in pseudo_lock_free()
394 	kfree(rdtgrp->plr);  in pseudo_lock_free()
395 	rdtgrp->plr = NULL;  in pseudo_lock_free()
399  * pseudo_lock_fn - Load kernel memory into cache
400  * @_rdtgrp: resource group to which pseudo-lock region belongs
402  * This is the core pseudo-locking flow.
407  * with class of service set to the bitmask of the pseudo-locked region.
420 	struct pseudo_lock_region *plr = rdtgrp->plr;  in pseudo_lock_fn()
431 	 * pseudo-locking success rate when KASAN is active.  in pseudo_lock_fn()
444 	 * will get a cache hit in below loop from outside of pseudo-locked  in pseudo_lock_fn()
463 	 * being pseudo-locked is reached the hardware will not read beyond  in pseudo_lock_fn()
464 	 * the buffer and evict pseudo-locked memory read earlier from the  in pseudo_lock_fn()
471 	mem_r = plr->kmem;  in pseudo_lock_fn()
472 	size = plr->size;  in pseudo_lock_fn()
473 	line_size = plr->line_size;  in pseudo_lock_fn()
477 	 * pseudo-locked followed by reading of kernel memory to load it  in pseudo_lock_fn()
480 	__wrmsr(IA32_PQR_ASSOC, rmid_p, rdtgrp->closid);  in pseudo_lock_fn()
483 	 * into cache region associated with just activated plr->closid.  in pseudo_lock_fn()
485 	 * - In first loop the cache region is shared with the page walker  in pseudo_lock_fn()
487 	 * - In the second loop the paging structure caches are used and  in pseudo_lock_fn()
514 	 * does not overlap with pseudo-locked region.  in pseudo_lock_fn()
518 	/* Re-enable the hardware prefetcher(s) */  in pseudo_lock_fn()
522 	plr->thread_done = 1;  in pseudo_lock_fn()
523 	wake_up_interruptible(&plr->lock_thread_wq);  in pseudo_lock_fn()
528  * rdtgroup_monitor_in_progress - Test if monitoring in progress
536 	return !list_empty(&rdtgrp->mon.crdtgrp_list);  in rdtgroup_monitor_in_progress()
540  * rdtgroup_locksetup_user_restrict - Restrict user access to group
543  * A resource group used for cache pseudo-locking cannot have cpus or tasks
590  * rdtgroup_locksetup_user_restore - Restore user access to group
637  * rdtgroup_locksetup_enter - Resource group enters locksetup mode
641  * to represent a pseudo-locked region and is in the process of being set
642  * up to do so. A resource group used for a pseudo-locked region would
645  * future. Monitoring of a pseudo-locked region is not allowed either.
647  * The above and more restrictions on a pseudo-locked region are checked
663 		rdt_last_cmd_puts("Cannot pseudo-lock default group\n");  in rdtgroup_locksetup_enter()
664 		return -EINVAL;  in rdtgroup_locksetup_enter()
668 	 * Cache Pseudo-locking not supported when CDP is enabled.  in rdtgroup_locksetup_enter()
672 	 * - When CDP is enabled two separate resources are exposed,  in rdtgroup_locksetup_enter()
674 	 *   The implication for pseudo-locking is that if a  in rdtgroup_locksetup_enter()
675 	 *   pseudo-locked region is created on a domain of one  in rdtgroup_locksetup_enter()
676 	 *   resource (eg. L3CODE), then a pseudo-locked region cannot  in rdtgroup_locksetup_enter()
679 	 *   pseudo-locked region involves a call to wbinvd that will  in rdtgroup_locksetup_enter()
681 	 * - Considering the previous, it may be possible to only  in rdtgroup_locksetup_enter()
682 	 *   expose one of the CDP resources to pseudo-locking and  in rdtgroup_locksetup_enter()
686 	 * - If only one region is exposed to pseudo-locking we should  in rdtgroup_locksetup_enter()
688 	 *   for pseudo-locking should take into account both resources.  in rdtgroup_locksetup_enter()
689 	 *   Similarly, if a pseudo-locked region is created in one  in rdtgroup_locksetup_enter()
696 		return -EINVAL;  in rdtgroup_locksetup_enter()
701 	 * platform does not support Cache Pseudo-Locking.  in rdtgroup_locksetup_enter()
705 		rdt_last_cmd_puts("Pseudo-locking not supported\n");  in rdtgroup_locksetup_enter()
706 		return -EINVAL;  in rdtgroup_locksetup_enter()
711 		return -EINVAL;  in rdtgroup_locksetup_enter()
716 		return -EINVAL;  in rdtgroup_locksetup_enter()
719 	if (!cpumask_empty(&rdtgrp->cpu_mask)) {  in rdtgroup_locksetup_enter()
721 		return -EINVAL;  in rdtgroup_locksetup_enter()
726 		return -EIO;  in rdtgroup_locksetup_enter()
731 		rdt_last_cmd_puts("Unable to init pseudo-lock region\n");  in rdtgroup_locksetup_enter()
738 	 * anymore when this group would be used for pseudo-locking. This  in rdtgroup_locksetup_enter()
741 	free_rmid(rdtgrp->mon.rmid);  in rdtgroup_locksetup_enter()
753  * rdtgroup_locksetup_exit - resource group exist locksetup mode
771 		rdtgrp->mon.rmid = ret;  in rdtgroup_locksetup_exit()
776 		free_rmid(rdtgrp->mon.rmid);  in rdtgroup_locksetup_exit()
785  * rdtgroup_cbm_overlaps_pseudo_locked - Test if CBM or portion is pseudo-locked
791  * pseudo-locked region on @d.
796  * Return: true if @cbm overlaps with pseudo-locked region on @d, false
804 	if (d->plr) {  in rdtgroup_cbm_overlaps_pseudo_locked()
805 		cbm_len = d->plr->s->res->cache.cbm_len;  in rdtgroup_cbm_overlaps_pseudo_locked()
806 		cbm_b = d->plr->cbm;  in rdtgroup_cbm_overlaps_pseudo_locked()
814  * rdtgroup_pseudo_locked_in_hierarchy - Pseudo-locked region in cache hierarchy
817  * The setup of a pseudo-locked region affects all cache instances within
819  * pseudo-locked regions exist within a cache hierarchy to prevent any
820  * attempts to create new pseudo-locked regions in the same hierarchy.
822  * Return: true if a pseudo-locked region exists in the hierarchy of @d or
837 	 * First determine which cpus have pseudo-locked regions  in rdtgroup_pseudo_locked_in_hierarchy()
841 		list_for_each_entry(d_i, &r->domains, list) {  in rdtgroup_pseudo_locked_in_hierarchy()
842 			if (d_i->plr)  in rdtgroup_pseudo_locked_in_hierarchy()
844 					   &d_i->cpu_mask);  in rdtgroup_pseudo_locked_in_hierarchy()
849 	 * Next test if new pseudo-locked region would intersect with  in rdtgroup_pseudo_locked_in_hierarchy()
852 	if (cpumask_intersects(&d->cpu_mask, cpu_with_psl))  in rdtgroup_pseudo_locked_in_hierarchy()
860  * measure_cycles_lat_fn - Measure cycle latency to read pseudo-locked memory
861  * @_plr: pseudo-lock region to measure
887 	mem_r = READ_ONCE(plr->kmem);  in measure_cycles_lat_fn()
893 	for (i = 0; i < plr->size; i += 32) {  in measure_cycles_lat_fn()
900 		trace_pseudo_lock_mem_latency((u32)(end - start));  in measure_cycles_lat_fn()
904 	plr->thread_done = 1;  in measure_cycles_lat_fn()
905 	wake_up_interruptible(&plr->lock_thread_wq);  in measure_cycles_lat_fn()
954 	miss_event = perf_event_create_kernel_counter(miss_attr, plr->cpu,  in measure_residency_fn()
959 	hit_event = perf_event_create_kernel_counter(hit_attr, plr->cpu,  in measure_residency_fn()
987 	 * interrupts disabled - it is thus safe to read the counter index.  in measure_residency_fn()
991 	line_size = READ_ONCE(plr->line_size);  in measure_residency_fn()
992 	mem_r = READ_ONCE(plr->kmem);  in measure_residency_fn()
993 	size = READ_ONCE(plr->size);  in measure_residency_fn()
996 	 * Read counter variables twice - first to load the instructions  in measure_residency_fn()
1003 	 * From SDM: Performing back-to-back fast reads are not guaranteed  in measure_residency_fn()
1039 	/* Re-enable hardware prefetchers */  in measure_residency_fn()
1050 	counts->miss_before = miss_before;  in measure_residency_fn()
1051 	counts->hits_before = hits_before;  in measure_residency_fn()
1052 	counts->miss_after  = miss_after;  in measure_residency_fn()
1053 	counts->hits_after  = hits_after;  in measure_residency_fn()
1063 	 * Non-architectural event for the Goldmont Microarchitecture  in measure_l2_residency()
1087 	trace_pseudo_lock_l2(counts.hits_after - counts.hits_before,  in measure_l2_residency()
1088 			     counts.miss_after - counts.miss_before);  in measure_l2_residency()
1090 	plr->thread_done = 1;  in measure_l2_residency()
1091 	wake_up_interruptible(&plr->lock_thread_wq);  in measure_l2_residency()
1127 	counts.miss_after -= counts.miss_before;  in measure_l3_residency()
1137 		counts.hits_after -= counts.hits_before;  in measure_l3_residency()
1139 		counts.hits_after -= min(counts.miss_after, counts.hits_after);  in measure_l3_residency()
1141 		counts.hits_after -= counts.hits_before;  in measure_l3_residency()
1146 	plr->thread_done = 1;  in measure_l3_residency()
1147 	wake_up_interruptible(&plr->lock_thread_wq);  in measure_l3_residency()
1152  * pseudo_lock_measure_cycles - Trigger latency measure to pseudo-locked region
1153  * @rdtgrp: Resource group to which the pseudo-locked region belongs.
1154  * @sel: Selector of which measurement to perform on a pseudo-locked region.
1156  * The measurement of latency to access a pseudo-locked region should be
1157  * done from a cpu that is associated with that pseudo-locked region.
1165 	struct pseudo_lock_region *plr = rdtgrp->plr;  in pseudo_lock_measure_cycles()
1168 	int ret = -1;  in pseudo_lock_measure_cycles()
1173 	if (rdtgrp->flags & RDT_DELETED) {  in pseudo_lock_measure_cycles()
1174 		ret = -ENODEV;  in pseudo_lock_measure_cycles()
1178 	if (!plr->d) {  in pseudo_lock_measure_cycles()
1179 		ret = -ENODEV;  in pseudo_lock_measure_cycles()
1183 	plr->thread_done = 0;  in pseudo_lock_measure_cycles()
1184 	cpu = cpumask_first(&plr->d->cpu_mask);  in pseudo_lock_measure_cycles()
1186 		ret = -ENODEV;  in pseudo_lock_measure_cycles()
1190 	plr->cpu = cpu;  in pseudo_lock_measure_cycles()
1217 	ret = wait_event_interruptible(plr->lock_thread_wq,  in pseudo_lock_measure_cycles()
1218 				       plr->thread_done == 1);  in pseudo_lock_measure_cycles()
1234 	struct rdtgroup *rdtgrp = file->private_data;  in pseudo_lock_measure_trigger()
1240 	buf_size = min(count, (sizeof(buf) - 1));  in pseudo_lock_measure_trigger()
1242 		return -EFAULT;  in pseudo_lock_measure_trigger()
1248 			return -EINVAL;  in pseudo_lock_measure_trigger()
1249 		ret = debugfs_file_get(file->f_path.dentry);  in pseudo_lock_measure_trigger()
1255 		debugfs_file_put(file->f_path.dentry);  in pseudo_lock_measure_trigger()
1268  * rdtgroup_pseudo_lock_create - Create a pseudo-locked region
1269  * @rdtgrp: resource group to which pseudo-lock region belongs
1271  * Called when a resource group in the pseudo-locksetup mode receives a
1272  * valid schemata that should be pseudo-locked. Since the resource group is
1273  * in pseudo-locksetup mode the &struct pseudo_lock_region has already been
1275  * occurs the resource group remains in the pseudo-locksetup mode with the
1277  * information and ready for the user to re-attempt pseudo-locking by
1280  * Return: 0 if the pseudo-locked region was successfully pseudo-locked, <0
1281  * on failure. Descriptive error will be written to last_cmd_status buffer.
1285 	struct pseudo_lock_region *plr = rdtgrp->plr;  in rdtgroup_pseudo_lock_create()
1297 		ret = -EINVAL;  in rdtgroup_pseudo_lock_create()
1301 	plr->thread_done = 0;  in rdtgroup_pseudo_lock_create()
1304 					cpu_to_node(plr->cpu),  in rdtgroup_pseudo_lock_create()
1305 					"pseudo_lock/%u", plr->cpu);  in rdtgroup_pseudo_lock_create()
1312 	kthread_bind(thread, plr->cpu);  in rdtgroup_pseudo_lock_create()
1315 	ret = wait_event_interruptible(plr->lock_thread_wq,  in rdtgroup_pseudo_lock_create()
1316 				       plr->thread_done == 1);  in rdtgroup_pseudo_lock_create()
1324 		 * empty pseudo-locking loop.  in rdtgroup_pseudo_lock_create()
1338 	 * pseudo-locked region will still be here on return.  in rdtgroup_pseudo_lock_create()
1341 	 * deadlock with the mm->mmap_lock which is obtained in the  in rdtgroup_pseudo_lock_create()
1348 		plr->debugfs_dir = debugfs_create_dir(rdtgrp->kn->name,  in rdtgroup_pseudo_lock_create()
1350 		if (!IS_ERR_OR_NULL(plr->debugfs_dir))  in rdtgroup_pseudo_lock_create()
1352 					    plr->debugfs_dir, rdtgrp,  in rdtgroup_pseudo_lock_create()
1358 			    rdtgrp, "%s", rdtgrp->kn->name);  in rdtgroup_pseudo_lock_create()
1369 	/* We released the mutex - check if group was removed while we did so */  in rdtgroup_pseudo_lock_create()
1370 	if (rdtgrp->flags & RDT_DELETED) {  in rdtgroup_pseudo_lock_create()
1371 		ret = -ENODEV;  in rdtgroup_pseudo_lock_create()
1375 	plr->minor = new_minor;  in rdtgroup_pseudo_lock_create()
1377 	rdtgrp->mode = RDT_MODE_PSEUDO_LOCKED;  in rdtgroup_pseudo_lock_create()
1378 	closid_free(rdtgrp->closid);  in rdtgroup_pseudo_lock_create()
1388 	debugfs_remove_recursive(plr->debugfs_dir);  in rdtgroup_pseudo_lock_create()
1399  * rdtgroup_pseudo_lock_remove - Remove a pseudo-locked region
1400  * @rdtgrp: resource group to which the pseudo-locked region belongs
1402  * The removal of a pseudo-locked region can be initiated when the resource
1405  * not go back to pseudo-locksetup mode before it is removed, instead it is
1414 	struct pseudo_lock_region *plr = rdtgrp->plr;  in rdtgroup_pseudo_lock_remove()
1416 	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {  in rdtgroup_pseudo_lock_remove()
1418 		 * Default group cannot be a pseudo-locked region so we can  in rdtgroup_pseudo_lock_remove()
1421 		closid_free(rdtgrp->closid);  in rdtgroup_pseudo_lock_remove()
1426 	debugfs_remove_recursive(rdtgrp->plr->debugfs_dir);  in rdtgroup_pseudo_lock_remove()
1427 	device_destroy(pseudo_lock_class, MKDEV(pseudo_lock_major, plr->minor));  in rdtgroup_pseudo_lock_remove()
1428 	pseudo_lock_minor_release(plr->minor);  in rdtgroup_pseudo_lock_remove()
1443 		return -ENODEV;  in pseudo_lock_dev_open()
1446 	filp->private_data = rdtgrp;  in pseudo_lock_dev_open()
1447 	atomic_inc(&rdtgrp->waitcount);  in pseudo_lock_dev_open()
1448 	/* Perform a non-seekable open - llseek is not supported */  in pseudo_lock_dev_open()
1449 	filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);  in pseudo_lock_dev_open()
1461 	rdtgrp = filp->private_data;  in pseudo_lock_dev_release()
1465 		return -ENODEV;  in pseudo_lock_dev_release()
1467 	filp->private_data = NULL;  in pseudo_lock_dev_release()
1468 	atomic_dec(&rdtgrp->waitcount);  in pseudo_lock_dev_release()
1476 	return -EINVAL;  in pseudo_lock_dev_mremap()
1485 	unsigned long vsize = vma->vm_end - vma->vm_start;  in pseudo_lock_dev_mmap()
1486 	unsigned long off = vma->vm_pgoff << PAGE_SHIFT;  in pseudo_lock_dev_mmap()
1494 	rdtgrp = filp->private_data;  in pseudo_lock_dev_mmap()
1498 		return -ENODEV;  in pseudo_lock_dev_mmap()
1501 	plr = rdtgrp->plr;  in pseudo_lock_dev_mmap()
1503 	if (!plr->d) {  in pseudo_lock_dev_mmap()
1505 		return -ENODEV;  in pseudo_lock_dev_mmap()
1510 	 * with the pseudo-locked region. If this is not the case the task  in pseudo_lock_dev_mmap()
1512 	 * pseudo-locked region.  in pseudo_lock_dev_mmap()
1514 	if (!cpumask_subset(current->cpus_ptr, &plr->d->cpu_mask)) {  in pseudo_lock_dev_mmap()
1516 		return -EINVAL;  in pseudo_lock_dev_mmap()
1519 	physical = __pa(plr->kmem) >> PAGE_SHIFT;  in pseudo_lock_dev_mmap()
1520 	psize = plr->size - off;  in pseudo_lock_dev_mmap()
1522 	if (off > plr->size) {  in pseudo_lock_dev_mmap()
1524 		return -ENOSPC;  in pseudo_lock_dev_mmap()
1529 	 * do not allow copy-on-write mapping.  in pseudo_lock_dev_mmap()
1531 	if (!(vma->vm_flags & VM_SHARED)) {  in pseudo_lock_dev_mmap()
1533 		return -EINVAL;  in pseudo_lock_dev_mmap()
1538 		return -ENOSPC;  in pseudo_lock_dev_mmap()
1541 	memset(plr->kmem + off, 0, vsize);  in pseudo_lock_dev_mmap()
1543 	if (remap_pfn_range(vma, vma->vm_start, physical + vma->vm_pgoff,  in pseudo_lock_dev_mmap()
1544 			    vsize, vma->vm_page_prot)) {  in pseudo_lock_dev_mmap()
1546 		return -EAGAIN;  in pseudo_lock_dev_mmap()
1548 	vma->vm_ops = &pseudo_mmap_ops;  in pseudo_lock_dev_mmap()
1570 	return kasprintf(GFP_KERNEL, "pseudo_lock/%s", rdtgrp->kn->name);  in pseudo_lock_devnode()
1590 	pseudo_lock_class->devnode = pseudo_lock_devnode;  in rdt_pseudo_lock_init()