1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright 2020-21 IBM Corp.
6 #define pr_fmt(fmt) "vas: " fmt
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/export.h>
11 #include <linux/types.h>
12 #include <linux/delay.h>
13 #include <linux/slab.h>
14 #include <linux/interrupt.h>
15 #include <linux/irqdomain.h>
16 #include <asm/machdep.h>
17 #include <asm/hvcall.h>
18 #include <asm/plpar_wrappers.h>
19 #include <asm/firmware.h>
24 #define VAS_INVALID_WIN_ADDRESS 0xFFFFFFFFFFFFFFFFul
25 #define VAS_DEFAULT_DOMAIN_ID 0xFFFFFFFFFFFFFFFFul
26 /* The hypervisor allows one credit per window right now */
27 #define DEF_WIN_CREDS 1
29 static struct vas_all_caps caps_all;
30 static bool copypaste_feat;
31 static struct hv_vas_cop_feat_caps hv_cop_caps;
33 static struct vas_caps vascaps[VAS_MAX_FEAT_TYPE];
34 static DEFINE_MUTEX(vas_pseries_mutex);
35 static bool migration_in_progress;
37 static long hcall_return_busy_check(long rc)
39 /* Check if we are stalled for some time */
40 if (H_IS_LONG_BUSY(rc)) {
41 msleep(get_longbusy_msecs(rc));
43 } else if (rc == H_BUSY) {
51 * Allocate VAS window hcall
53 static int h_allocate_vas_window(struct pseries_vas_window *win, u64 *domain,
54 u8 wintype, u16 credits)
56 long retbuf[PLPAR_HCALL9_BUFSIZE] = {0};
60 rc = plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, wintype,
61 credits, domain[0], domain[1], domain[2],
62 domain[3], domain[4], domain[5]);
64 rc = hcall_return_busy_check(rc);
65 } while (rc == H_BUSY);
67 if (rc == H_SUCCESS) {
68 if (win->win_addr == VAS_INVALID_WIN_ADDRESS) {
69 pr_err("H_ALLOCATE_VAS_WINDOW: COPY/PASTE is not supported\n");
72 win->vas_win.winid = retbuf[0];
73 win->win_addr = retbuf[1];
74 win->complete_irq = retbuf[2];
75 win->fault_irq = retbuf[3];
79 pr_err("H_ALLOCATE_VAS_WINDOW error: %ld, wintype: %u, credits: %u\n",
80 rc, wintype, credits);
86 * Deallocate VAS window hcall.
88 static int h_deallocate_vas_window(u64 winid)
93 rc = plpar_hcall_norets(H_DEALLOCATE_VAS_WINDOW, winid);
95 rc = hcall_return_busy_check(rc);
96 } while (rc == H_BUSY);
101 pr_err("H_DEALLOCATE_VAS_WINDOW error: %ld, winid: %llu\n",
108 * After the window is opened with allocate window hcall, configure it
109 * with flags and LPAR PID before using.
111 static int h_modify_vas_window(struct pseries_vas_window *win)
116 * AMR value is not supported in Linux VAS implementation.
117 * The hypervisor ignores it if 0 is passed.
120 rc = plpar_hcall_norets(H_MODIFY_VAS_WINDOW,
121 win->vas_win.winid, win->pid, 0,
122 VAS_MOD_WIN_FLAGS, 0);
124 rc = hcall_return_busy_check(rc);
125 } while (rc == H_BUSY);
130 pr_err("H_MODIFY_VAS_WINDOW error: %ld, winid %u pid %u\n",
131 rc, win->vas_win.winid, win->pid);
136 * This hcall is used to determine the capabilities from the hypervisor.
137 * @hcall: H_QUERY_VAS_CAPABILITIES or H_QUERY_NX_CAPABILITIES
138 * @query_type: If 0 is passed, the hypervisor returns the overall
139 * capabilities which provides all feature(s) that are
140 * available. Then query the hypervisor to get the
141 * corresponding capabilities for the specific feature.
142 * Example: H_QUERY_VAS_CAPABILITIES provides VAS GZIP QoS
143 * and VAS GZIP Default capabilities.
144 * H_QUERY_NX_CAPABILITIES provides NX GZIP
146 * @result: Return buffer to save capabilities.
148 int h_query_vas_capabilities(const u64 hcall, u8 query_type, u64 result)
152 rc = plpar_hcall_norets(hcall, query_type, result);
157 /* H_FUNCTION means HV does not support VAS so don't print an error */
158 if (rc != H_FUNCTION) {
159 pr_err("%s error %ld, query_type %u, result buffer 0x%llx\n",
160 (hcall == H_QUERY_VAS_CAPABILITIES) ?
161 "H_QUERY_VAS_CAPABILITIES" :
162 "H_QUERY_NX_CAPABILITIES",
163 rc, query_type, result);
168 EXPORT_SYMBOL_GPL(h_query_vas_capabilities);
171 * hcall to get fault CRB from the hypervisor.
173 static int h_get_nx_fault(u32 winid, u64 buffer)
177 rc = plpar_hcall_norets(H_GET_NX_FAULT, winid, buffer);
182 pr_err("H_GET_NX_FAULT error: %ld, winid %u, buffer 0x%llx\n",
189 * Handle the fault interrupt.
190 * When the fault interrupt is received for each window, query the
191 * hypervisor to get the fault CRB on the specific fault. Then
192 * process the CRB by updating CSB or send signal if the user space
194 * Note: The hypervisor forwards an interrupt for each fault request.
195 * So one fault CRB to process for each H_GET_NX_FAULT hcall.
197 static irqreturn_t pseries_vas_fault_thread_fn(int irq, void *data)
199 struct pseries_vas_window *txwin = data;
200 struct coprocessor_request_block crb;
201 struct vas_user_win_ref *tsk_ref;
204 while (atomic_read(&txwin->pending_faults)) {
205 rc = h_get_nx_fault(txwin->vas_win.winid, (u64)virt_to_phys(&crb));
207 tsk_ref = &txwin->vas_win.task_ref;
209 vas_update_csb(&crb, tsk_ref);
211 atomic_dec(&txwin->pending_faults);
218 * irq_default_primary_handler() can be used only with IRQF_ONESHOT
219 * which disables IRQ before executing the thread handler and enables
220 * it after. But this disabling interrupt sets the VAS IRQ OFF
221 * state in the hypervisor. If the NX generates fault interrupt
222 * during this window, the hypervisor will not deliver this
223 * interrupt to the LPAR. So use VAS specific IRQ handler instead
224 * of calling the default primary handler.
226 static irqreturn_t pseries_vas_irq_handler(int irq, void *data)
228 struct pseries_vas_window *txwin = data;
231 * The thread hanlder will process this interrupt if it is
234 atomic_inc(&txwin->pending_faults);
236 return IRQ_WAKE_THREAD;
240 * Allocate window and setup IRQ mapping.
242 static int allocate_setup_window(struct pseries_vas_window *txwin,
243 u64 *domain, u8 wintype)
247 rc = h_allocate_vas_window(txwin, domain, wintype, DEF_WIN_CREDS);
251 * On PowerVM, the hypervisor setup and forwards the fault
252 * interrupt per window. So the IRQ setup and fault handling
253 * will be done for each open window separately.
255 txwin->fault_virq = irq_create_mapping(NULL, txwin->fault_irq);
256 if (!txwin->fault_virq) {
257 pr_err("Failed irq mapping %d\n", txwin->fault_irq);
262 txwin->name = kasprintf(GFP_KERNEL, "vas-win-%d",
263 txwin->vas_win.winid);
269 rc = request_threaded_irq(txwin->fault_virq,
270 pseries_vas_irq_handler,
271 pseries_vas_fault_thread_fn, 0,
274 pr_err("VAS-Window[%d]: Request IRQ(%u) failed with %d\n",
275 txwin->vas_win.winid, txwin->fault_virq, rc);
279 txwin->vas_win.wcreds_max = DEF_WIN_CREDS;
285 irq_dispose_mapping(txwin->fault_virq);
287 h_deallocate_vas_window(txwin->vas_win.winid);
291 static inline void free_irq_setup(struct pseries_vas_window *txwin)
293 free_irq(txwin->fault_virq, txwin);
295 irq_dispose_mapping(txwin->fault_virq);
298 static struct vas_window *vas_allocate_window(int vas_id, u64 flags,
299 enum vas_cop_type cop_type)
301 long domain[PLPAR_HCALL9_BUFSIZE] = {VAS_DEFAULT_DOMAIN_ID};
302 struct vas_cop_feat_caps *cop_feat_caps;
303 struct vas_caps *caps;
304 struct pseries_vas_window *txwin;
307 txwin = kzalloc(sizeof(*txwin), GFP_KERNEL);
309 return ERR_PTR(-ENOMEM);
312 * A VAS window can have many credits which means that many
313 * requests can be issued simultaneously. But the hypervisor
314 * restricts one credit per window.
315 * The hypervisor introduces 2 different types of credits:
316 * Default credit type (Uses normal priority FIFO):
317 * A limited number of credits are assigned to partitions
318 * based on processor entitlement. But these credits may be
319 * over-committed on a system depends on whether the CPUs
320 * are in shared or dedicated modes - that is, more requests
321 * may be issued across the system than NX can service at
322 * once which can result in paste command failure (RMA_busy).
323 * Then the process has to resend requests or fall-back to
325 * Quality of Service (QoS) credit type (Uses high priority FIFO):
326 * To avoid NX HW contention, the system admins can assign
327 * QoS credits for each LPAR so that this partition is
328 * guaranteed access to NX resources. These credits are
329 * assigned to partitions via the HMC.
330 * Refer PAPR for more information.
332 * Allocate window with QoS credits if user requested. Otherwise
333 * default credits are used.
335 if (flags & VAS_TX_WIN_FLAG_QOS_CREDIT)
336 caps = &vascaps[VAS_GZIP_QOS_FEAT_TYPE];
338 caps = &vascaps[VAS_GZIP_DEF_FEAT_TYPE];
340 cop_feat_caps = &caps->caps;
342 if (atomic_inc_return(&cop_feat_caps->nr_used_credits) >
343 atomic_read(&cop_feat_caps->nr_total_credits)) {
344 pr_err_ratelimited("Credits are not available to allocate window\n");
351 * The user space is requesting to allocate a window on
352 * a VAS instance where the process is executing.
353 * On PowerVM, domain values are passed to the hypervisor
354 * to select VAS instance. Useful if the process is
355 * affinity to NUMA node.
356 * The hypervisor selects VAS instance if
357 * VAS_DEFAULT_DOMAIN_ID (-1) is passed for domain values.
358 * The h_allocate_vas_window hcall is defined to take a
359 * domain values as specified by h_home_node_associativity,
360 * So no unpacking needs to be done.
362 rc = plpar_hcall9(H_HOME_NODE_ASSOCIATIVITY, domain,
363 VPHN_FLAG_VCPU, hard_smp_processor_id());
364 if (rc != H_SUCCESS) {
365 pr_err("H_HOME_NODE_ASSOCIATIVITY error: %d\n", rc);
370 txwin->pid = mfspr(SPRN_PID);
373 * Allocate / Deallocate window hcalls and setup / free IRQs
374 * have to be protected with mutex.
375 * Open VAS window: Allocate window hcall and setup IRQ
376 * Close VAS window: Deallocate window hcall and free IRQ
377 * The hypervisor waits until all NX requests are
378 * completed before closing the window. So expects OS
379 * to handle NX faults, means IRQ can be freed only
380 * after the deallocate window hcall is returned.
381 * So once the window is closed with deallocate hcall before
382 * the IRQ is freed, it can be assigned to new allocate
383 * hcall with the same fault IRQ by the hypervisor. It can
384 * result in setup IRQ fail for the new window since the
385 * same fault IRQ is not freed by the OS before.
387 mutex_lock(&vas_pseries_mutex);
388 if (migration_in_progress) {
391 rc = allocate_setup_window(txwin, (u64 *)&domain[0],
392 cop_feat_caps->win_type);
394 caps->nr_open_wins_progress++;
397 mutex_unlock(&vas_pseries_mutex);
402 * Modify window and it is ready to use.
404 rc = h_modify_vas_window(txwin);
406 rc = get_vas_user_win_ref(&txwin->vas_win.task_ref);
410 txwin->win_type = cop_feat_caps->win_type;
413 * The migration SUSPEND thread sets migration_in_progress and
414 * closes all open windows from the list. But the window is
415 * added to the list after open and modify HCALLs. So possible
416 * that migration_in_progress is set before modify HCALL which
417 * may cause some windows are still open when the hypervisor
418 * initiates the migration.
419 * So checks the migration_in_progress flag again and close all
422 * Possible to lose the acquired credit with DLPAR core
423 * removal after the window is opened. So if there are any
424 * closed windows (means with lost credits), do not give new
425 * window to user space. New windows will be opened only
426 * after the existing windows are reopened when credits are
429 mutex_lock(&vas_pseries_mutex);
430 if (!caps->nr_close_wins && !migration_in_progress) {
431 list_add(&txwin->win_list, &caps->list);
432 caps->nr_open_windows++;
433 caps->nr_open_wins_progress--;
434 mutex_unlock(&vas_pseries_mutex);
435 vas_user_win_add_mm_context(&txwin->vas_win.task_ref);
436 return &txwin->vas_win;
438 mutex_unlock(&vas_pseries_mutex);
440 put_vas_user_win_ref(&txwin->vas_win.task_ref);
442 pr_err_ratelimited("No credit is available to allocate window\n");
446 * Window is not operational. Free IRQ before closing
447 * window so that do not have to hold mutex.
449 free_irq_setup(txwin);
450 h_deallocate_vas_window(txwin->vas_win.winid);
452 * Hold mutex and reduce nr_open_wins_progress counter.
454 mutex_lock(&vas_pseries_mutex);
455 caps->nr_open_wins_progress--;
456 mutex_unlock(&vas_pseries_mutex);
458 atomic_dec(&cop_feat_caps->nr_used_credits);
463 static u64 vas_paste_address(struct vas_window *vwin)
465 struct pseries_vas_window *win;
467 win = container_of(vwin, struct pseries_vas_window, vas_win);
468 return win->win_addr;
471 static int deallocate_free_window(struct pseries_vas_window *win)
476 * The hypervisor waits for all requests including faults
477 * are processed before closing the window - Means all
478 * credits have to be returned. In the case of fault
479 * request, a credit is returned after OS issues
480 * H_GET_NX_FAULT hcall.
481 * So free IRQ after executing H_DEALLOCATE_VAS_WINDOW
484 rc = h_deallocate_vas_window(win->vas_win.winid);
491 static int vas_deallocate_window(struct vas_window *vwin)
493 struct pseries_vas_window *win;
494 struct vas_cop_feat_caps *caps;
500 win = container_of(vwin, struct pseries_vas_window, vas_win);
502 /* Should not happen */
503 if (win->win_type >= VAS_MAX_FEAT_TYPE) {
504 pr_err("Window (%u): Invalid window type %u\n",
505 vwin->winid, win->win_type);
509 caps = &vascaps[win->win_type].caps;
510 mutex_lock(&vas_pseries_mutex);
512 * VAS window is already closed in the hypervisor when
513 * lost the credit or with migration. So just remove the entry
514 * from the list, remove task references and free vas_window
517 if (!(win->vas_win.status & VAS_WIN_NO_CRED_CLOSE) &&
518 !(win->vas_win.status & VAS_WIN_MIGRATE_CLOSE)) {
519 rc = deallocate_free_window(win);
521 mutex_unlock(&vas_pseries_mutex);
525 vascaps[win->win_type].nr_close_wins--;
527 list_del(&win->win_list);
528 atomic_dec(&caps->nr_used_credits);
529 vascaps[win->win_type].nr_open_windows--;
530 mutex_unlock(&vas_pseries_mutex);
532 mm_context_remove_vas_window(vwin->task_ref.mm);
533 put_vas_user_win_ref(&vwin->task_ref);
539 static const struct vas_user_win_ops vops_pseries = {
540 .open_win = vas_allocate_window, /* Open and configure window */
541 .paste_addr = vas_paste_address, /* To do copy/paste */
542 .close_win = vas_deallocate_window, /* Close window */
546 * Supporting only nx-gzip coprocessor type now, but this API code
547 * extended to other coprocessor types later.
549 int vas_register_api_pseries(struct module *mod, enum vas_cop_type cop_type,
555 return vas_register_coproc_api(mod, cop_type, name, &vops_pseries);
557 EXPORT_SYMBOL_GPL(vas_register_api_pseries);
559 void vas_unregister_api_pseries(void)
561 vas_unregister_coproc_api();
563 EXPORT_SYMBOL_GPL(vas_unregister_api_pseries);
566 * Get the specific capabilities based on the feature type.
567 * Right now supports GZIP default and GZIP QoS capabilities.
569 static int __init get_vas_capabilities(u8 feat, enum vas_cop_feat_type type,
570 struct hv_vas_cop_feat_caps *hv_caps)
572 struct vas_cop_feat_caps *caps;
573 struct vas_caps *vcaps;
576 vcaps = &vascaps[type];
577 memset(vcaps, 0, sizeof(*vcaps));
578 INIT_LIST_HEAD(&vcaps->list);
583 rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES, feat,
584 (u64)virt_to_phys(hv_caps));
588 caps->user_mode = hv_caps->user_mode;
589 if (!(caps->user_mode & VAS_COPY_PASTE_USER_MODE)) {
590 pr_err("User space COPY/PASTE is not supported\n");
594 caps->descriptor = be64_to_cpu(hv_caps->descriptor);
595 caps->win_type = hv_caps->win_type;
596 if (caps->win_type >= VAS_MAX_FEAT_TYPE) {
597 pr_err("Unsupported window type %u\n", caps->win_type);
600 caps->max_lpar_creds = be16_to_cpu(hv_caps->max_lpar_creds);
601 caps->max_win_creds = be16_to_cpu(hv_caps->max_win_creds);
602 atomic_set(&caps->nr_total_credits,
603 be16_to_cpu(hv_caps->target_lpar_creds));
604 if (feat == VAS_GZIP_DEF_FEAT) {
605 caps->def_lpar_creds = be16_to_cpu(hv_caps->def_lpar_creds);
607 if (caps->max_win_creds < DEF_WIN_CREDS) {
608 pr_err("Window creds(%u) > max allowed window creds(%u)\n",
609 DEF_WIN_CREDS, caps->max_win_creds);
614 rc = sysfs_add_vas_caps(caps);
618 copypaste_feat = true;
624 * VAS windows can be closed due to lost credits when the core is
625 * removed. So reopen them if credits are available due to DLPAR
626 * core add and set the window active status. When NX sees the page
627 * fault on the unmapped paste address, the kernel handles the fault
628 * by setting the remapping to new paste address if the window is
631 static int reconfig_open_windows(struct vas_caps *vcaps, int creds,
634 long domain[PLPAR_HCALL9_BUFSIZE] = {VAS_DEFAULT_DOMAIN_ID};
635 struct vas_cop_feat_caps *caps = &vcaps->caps;
636 struct pseries_vas_window *win = NULL, *tmp;
641 * Nothing to do if there are no closed windows.
643 if (!vcaps->nr_close_wins)
647 * For the core removal, the hypervisor reduces the credits
648 * assigned to the LPAR and the kernel closes VAS windows
649 * in the hypervisor depends on reduced credits. The kernel
650 * uses LIFO (the last windows that are opened will be closed
651 * first) and expects to open in the same order when credits
653 * For example, 40 windows are closed when the LPAR lost 2 cores
654 * (dedicated). If 1 core is added, this LPAR can have 20 more
655 * credits. It means the kernel can reopen 20 windows. So move
656 * 20 entries in the VAS windows lost and reopen next 20 windows.
657 * For partition migration, reopen all windows that are closed
660 if ((vcaps->nr_close_wins > creds) && !migrate)
661 mv_ents = vcaps->nr_close_wins - creds;
663 list_for_each_entry_safe(win, tmp, &vcaps->list, win_list) {
671 * Open windows if they are closed only with migration or
672 * DLPAR (lost credit) before.
675 flag = VAS_WIN_MIGRATE_CLOSE;
677 flag = VAS_WIN_NO_CRED_CLOSE;
679 list_for_each_entry_safe_from(win, tmp, &vcaps->list, win_list) {
681 * This window is closed with DLPAR and migration events.
682 * So reopen the window with the last event.
683 * The user space is not suspended with the current
684 * migration notifier. So the user space can issue DLPAR
685 * CPU hotplug while migration in progress. In this case
686 * this window will be opened with the last event.
688 if ((win->vas_win.status & VAS_WIN_NO_CRED_CLOSE) &&
689 (win->vas_win.status & VAS_WIN_MIGRATE_CLOSE)) {
690 win->vas_win.status &= ~flag;
695 * Nothing to do on this window if it is not closed
698 if (!(win->vas_win.status & flag))
701 rc = allocate_setup_window(win, (u64 *)&domain[0],
706 rc = h_modify_vas_window(win);
710 mutex_lock(&win->vas_win.task_ref.mmap_mutex);
712 * Set window status to active
714 win->vas_win.status &= ~flag;
715 mutex_unlock(&win->vas_win.task_ref.mmap_mutex);
716 win->win_type = caps->win_type;
717 if (!--vcaps->nr_close_wins)
724 * Window modify HCALL failed. So close the window to the
725 * hypervisor and return.
728 h_deallocate_vas_window(win->vas_win.winid);
733 * The hypervisor reduces the available credits if the LPAR lost core. It
734 * means the excessive windows should not be active and the user space
735 * should not be using these windows to send compression requests to NX.
736 * So the kernel closes the excessive windows and unmap the paste address
737 * such that the user space receives paste instruction failure. Then up to
738 * the user space to fall back to SW compression and manage with the
741 static int reconfig_close_windows(struct vas_caps *vcap, int excess_creds,
744 struct pseries_vas_window *win, *tmp;
745 struct vas_user_win_ref *task_ref;
746 struct vm_area_struct *vma;
750 flag = VAS_WIN_MIGRATE_CLOSE;
752 flag = VAS_WIN_NO_CRED_CLOSE;
754 list_for_each_entry_safe(win, tmp, &vcap->list, win_list) {
756 * This window is already closed due to lost credit
757 * or for migration before. Go for next window.
758 * For migration, nothing to do since this window
759 * closed for DLPAR and will be reopened even on
760 * the destination system with other DLPAR operation.
762 if ((win->vas_win.status & VAS_WIN_MIGRATE_CLOSE) ||
763 (win->vas_win.status & VAS_WIN_NO_CRED_CLOSE)) {
764 win->vas_win.status |= flag;
768 task_ref = &win->vas_win.task_ref;
770 * VAS mmap (coproc_mmap()) and its fault handler
771 * (vas_mmap_fault()) are called after holding mmap lock.
772 * So hold mmap mutex after mmap_lock to avoid deadlock.
774 mmap_write_lock(task_ref->mm);
775 mutex_lock(&task_ref->mmap_mutex);
778 * Number of available credits are reduced, So select
781 win->vas_win.status |= flag;
784 * vma is set in the original mapping. But this mapping
785 * is done with mmap() after the window is opened with ioctl.
786 * so we may not see the original mapping if the core remove
787 * is done before the original mmap() and after the ioctl.
792 mutex_unlock(&task_ref->mmap_mutex);
793 mmap_write_unlock(task_ref->mm);
795 * Close VAS window in the hypervisor, but do not
796 * free vas_window struct since it may be reused
797 * when the credit is available later (DLPAR with
798 * adding cores). This struct will be used
799 * later when the process issued with close(FD).
801 rc = deallocate_free_window(win);
803 * This failure is from the hypervisor.
804 * No way to stop migration for these failures.
805 * So ignore error and continue closing other windows.
810 vcap->nr_close_wins++;
813 * For migration, do not depend on lpar_creds in case if
814 * mismatch with the hypervisor value (should not happen).
815 * So close all active windows in the list and will be
816 * reopened windows based on the new lpar_creds on the
817 * destination system during resume.
819 if (!migrate && !--excess_creds)
827 * Get new VAS capabilities when the core add/removal configuration
828 * changes. Reconfig window configurations based on the credits
829 * availability from this new capabilities.
831 int vas_reconfig_capabilties(u8 type, int new_nr_creds)
833 struct vas_cop_feat_caps *caps;
835 struct vas_caps *vcaps;
836 int rc = 0, nr_active_wins;
838 if (type >= VAS_MAX_FEAT_TYPE) {
839 pr_err("Invalid credit type %d\n", type);
843 vcaps = &vascaps[type];
846 mutex_lock(&vas_pseries_mutex);
848 old_nr_creds = atomic_read(&caps->nr_total_credits);
850 atomic_set(&caps->nr_total_credits, new_nr_creds);
852 * The total number of available credits may be decreased or
853 * increased with DLPAR operation. Means some windows have to be
854 * closed / reopened. Hold the vas_pseries_mutex so that the
855 * user space can not open new windows.
857 if (old_nr_creds < new_nr_creds) {
859 * If the existing target credits is less than the new
860 * target, reopen windows if they are closed due to
861 * the previous DLPAR (core removal).
863 rc = reconfig_open_windows(vcaps, new_nr_creds - old_nr_creds,
867 * # active windows is more than new LPAR available
868 * credits. So close the excessive windows.
869 * On pseries, each window will have 1 credit.
871 nr_active_wins = vcaps->nr_open_windows - vcaps->nr_close_wins;
872 if (nr_active_wins > new_nr_creds)
873 rc = reconfig_close_windows(vcaps,
874 nr_active_wins - new_nr_creds,
878 mutex_unlock(&vas_pseries_mutex);
882 int pseries_vas_dlpar_cpu(void)
884 int new_nr_creds, rc;
887 * NX-GZIP is not enabled. Nothing to do for DLPAR event
893 rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES,
894 vascaps[VAS_GZIP_DEF_FEAT_TYPE].feat,
895 (u64)virt_to_phys(&hv_cop_caps));
897 new_nr_creds = be16_to_cpu(hv_cop_caps.target_lpar_creds);
898 rc = vas_reconfig_capabilties(VAS_GZIP_DEF_FEAT_TYPE, new_nr_creds);
902 pr_err("Failed reconfig VAS capabilities with DLPAR\n");
908 * Total number of default credits available (target_credits)
909 * in LPAR depends on number of cores configured. It varies based on
910 * whether processors are in shared mode or dedicated mode.
911 * Get the notifier when CPU configuration is changed with DLPAR
912 * operation so that get the new target_credits (vas default capabilities)
913 * and then update the existing windows usage if needed.
915 static int pseries_vas_notifier(struct notifier_block *nb,
916 unsigned long action, void *data)
918 struct of_reconfig_data *rd = data;
919 struct device_node *dn = rd->dn;
920 const __be32 *intserv = NULL;
924 * For shared CPU partition, the hypervisor assigns total credits
925 * based on entitled core capacity. So updating VAS windows will
926 * be called from lparcfg_write().
928 if (is_shared_processor())
931 if ((action == OF_RECONFIG_ATTACH_NODE) ||
932 (action == OF_RECONFIG_DETACH_NODE))
933 intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s",
936 * Processor config is not changed
941 return pseries_vas_dlpar_cpu();
944 static struct notifier_block pseries_vas_nb = {
945 .notifier_call = pseries_vas_notifier,
949 * For LPM, all windows have to be closed on the source partition
950 * before migration and reopen them on the destination partition
951 * after migration. So closing windows during suspend and
952 * reopen them during resume.
954 int vas_migration_handler(int action)
956 struct vas_cop_feat_caps *caps;
957 int old_nr_creds, new_nr_creds = 0;
958 struct vas_caps *vcaps;
961 pr_info("VAS migration event %d\n", action);
964 * NX-GZIP is not enabled. Nothing to do for migration.
969 if (action == VAS_SUSPEND)
970 migration_in_progress = true;
972 migration_in_progress = false;
974 for (i = 0; i < VAS_MAX_FEAT_TYPE; i++) {
977 old_nr_creds = atomic_read(&caps->nr_total_credits);
979 rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES,
981 (u64)virt_to_phys(&hv_cop_caps));
983 new_nr_creds = be16_to_cpu(hv_cop_caps.target_lpar_creds);
985 * Should not happen. But incase print messages, close
986 * all windows in the list during suspend and reopen
987 * windows based on new lpar_creds on the destination
990 if (old_nr_creds != new_nr_creds) {
991 pr_err("Target credits mismatch with the hypervisor\n");
992 pr_err("state(%d): lpar creds: %d HV lpar creds: %d\n",
993 action, old_nr_creds, new_nr_creds);
994 pr_err("Used creds: %d, Active creds: %d\n",
995 atomic_read(&caps->nr_used_credits),
996 vcaps->nr_open_windows - vcaps->nr_close_wins);
999 pr_err("state(%d): Get VAS capabilities failed with %d\n",
1002 * We can not stop migration with the current lpm
1003 * implementation. So continue closing all windows in
1004 * the list (during suspend) and return without
1005 * opening windows (during resume) if VAS capabilities
1008 if (action == VAS_RESUME)
1014 mutex_lock(&vas_pseries_mutex);
1015 rc = reconfig_close_windows(vcaps, vcaps->nr_open_windows,
1018 * Windows are included in the list after successful
1019 * open. So wait for closing these in-progress open
1020 * windows in vas_allocate_window() which will be
1021 * done if the migration_in_progress is set.
1023 while (vcaps->nr_open_wins_progress) {
1024 mutex_unlock(&vas_pseries_mutex);
1026 mutex_lock(&vas_pseries_mutex);
1028 mutex_unlock(&vas_pseries_mutex);
1031 mutex_lock(&vas_pseries_mutex);
1032 atomic_set(&caps->nr_total_credits, new_nr_creds);
1033 rc = reconfig_open_windows(vcaps, new_nr_creds, true);
1034 mutex_unlock(&vas_pseries_mutex);
1037 /* should not happen */
1038 pr_err("Invalid migration action %d\n", action);
1044 * Ignore errors during suspend and return for resume.
1046 if (rc && (action == VAS_RESUME))
1050 pr_info("VAS migration event (%d) successful\n", action);
1056 static int __init pseries_vas_init(void)
1058 struct hv_vas_all_caps *hv_caps;
1062 * Linux supports user space COPY/PASTE only with Radix
1064 if (!radix_enabled()) {
1065 copypaste_feat = false;
1066 pr_err("API is supported only with radix page tables\n");
1070 hv_caps = kmalloc(sizeof(*hv_caps), GFP_KERNEL);
1074 * Get VAS overall capabilities by passing 0 to feature type.
1076 rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES, 0,
1077 (u64)virt_to_phys(hv_caps));
1081 caps_all.descriptor = be64_to_cpu(hv_caps->descriptor);
1082 caps_all.feat_type = be64_to_cpu(hv_caps->feat_type);
1084 sysfs_pseries_vas_init(&caps_all);
1087 * QOS capabilities available
1089 if (caps_all.feat_type & VAS_GZIP_QOS_FEAT_BIT) {
1090 rc = get_vas_capabilities(VAS_GZIP_QOS_FEAT,
1091 VAS_GZIP_QOS_FEAT_TYPE, &hv_cop_caps);
1097 * Default capabilities available
1099 if (caps_all.feat_type & VAS_GZIP_DEF_FEAT_BIT)
1100 rc = get_vas_capabilities(VAS_GZIP_DEF_FEAT,
1101 VAS_GZIP_DEF_FEAT_TYPE, &hv_cop_caps);
1103 if (!rc && copypaste_feat) {
1104 if (firmware_has_feature(FW_FEATURE_LPAR))
1105 of_reconfig_notifier_register(&pseries_vas_nb);
1107 pr_info("GZIP feature is available\n");
1110 * Should not happen, but only when get default
1111 * capabilities HCALL failed. So disable copy paste
1114 copypaste_feat = false;
1121 machine_device_initcall(pseries, pseries_vas_init);