Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'powerpc-6.7-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Fix a bug where heavy VAS (accelerator) usage could race with
partition migration and prevent the migration from completing.
- Update MAINTAINERS to add Aneesh & Naveen.
Thanks to Haren Myneni.
* tag 'powerpc-6.7-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
MAINTAINERS: powerpc: Add Aneesh & Naveen
powerpc/pseries/vas: Migration suspend waits for no in-progress open windows
+48
-7
+2
MAINTAINERS
+2
MAINTAINERS
···
12189
12189
M: Michael Ellerman <mpe@ellerman.id.au>
12190
12190
R: Nicholas Piggin <npiggin@gmail.com>
12191
12191
R: Christophe Leroy <christophe.leroy@csgroup.eu>
12192
+
R: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
12193
+
R: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
12192
12194
L: linuxppc-dev@lists.ozlabs.org
12193
12195
S: Supported
12194
12196
W: https://github.com/linuxppc/wiki/wiki
+44
-7
arch/powerpc/platforms/pseries/vas.c
+44
-7
arch/powerpc/platforms/pseries/vas.c
···
385
385
* same fault IRQ is not freed by the OS before.
386
386
*/
387
387
mutex_lock(&vas_pseries_mutex);
388
-
if (migration_in_progress)
388
+
if (migration_in_progress) {
389
389
rc = -EBUSY;
390
-
else
390
+
} else {
391
391
rc = allocate_setup_window(txwin, (u64 *)&domain[0],
392
392
cop_feat_caps->win_type);
393
+
if (!rc)
394
+
caps->nr_open_wins_progress++;
395
+
}
396
+
393
397
mutex_unlock(&vas_pseries_mutex);
394
398
if (rc)
395
399
goto out;
···
408
404
goto out_free;
409
405
410
406
txwin->win_type = cop_feat_caps->win_type;
411
-
mutex_lock(&vas_pseries_mutex);
407
+
412
408
/*
409
+
* The migration SUSPEND thread sets migration_in_progress and
410
+
* closes all open windows from the list. But the window is
411
+
* added to the list after open and modify HCALLs. So possible
412
+
* that migration_in_progress is set before modify HCALL which
413
+
* may cause some windows are still open when the hypervisor
414
+
* initiates the migration.
415
+
* So checks the migration_in_progress flag again and close all
416
+
* open windows.
417
+
*
413
418
* Possible to lose the acquired credit with DLPAR core
414
419
* removal after the window is opened. So if there are any
415
420
* closed windows (means with lost credits), do not give new
···
426
413
* after the existing windows are reopened when credits are
427
414
* available.
428
415
*/
429
-
if (!caps->nr_close_wins) {
416
+
mutex_lock(&vas_pseries_mutex);
417
+
if (!caps->nr_close_wins && !migration_in_progress) {
430
418
list_add(&txwin->win_list, &caps->list);
431
419
caps->nr_open_windows++;
420
+
caps->nr_open_wins_progress--;
432
421
mutex_unlock(&vas_pseries_mutex);
433
422
vas_user_win_add_mm_context(&txwin->vas_win.task_ref);
434
423
return &txwin->vas_win;
···
448
433
*/
449
434
free_irq_setup(txwin);
450
435
h_deallocate_vas_window(txwin->vas_win.winid);
436
+
/*
437
+
* Hold mutex and reduce nr_open_wins_progress counter.
438
+
*/
439
+
mutex_lock(&vas_pseries_mutex);
440
+
caps->nr_open_wins_progress--;
441
+
mutex_unlock(&vas_pseries_mutex);
451
442
out:
452
443
atomic_dec(&cop_feat_caps->nr_used_credits);
453
444
kfree(txwin);
···
958
937
struct vas_caps *vcaps;
959
938
int i, rc = 0;
960
939
940
+
pr_info("VAS migration event %d\n", action);
941
+
961
942
/*
962
943
* NX-GZIP is not enabled. Nothing to do for migration.
963
944
*/
964
945
if (!copypaste_feat)
965
946
return rc;
966
-
967
-
mutex_lock(&vas_pseries_mutex);
968
947
969
948
if (action == VAS_SUSPEND)
970
949
migration_in_progress = true;
···
1011
990
1012
991
switch (action) {
1013
992
case VAS_SUSPEND:
993
+
mutex_lock(&vas_pseries_mutex);
1014
994
rc = reconfig_close_windows(vcaps, vcaps->nr_open_windows,
1015
995
true);
996
+
/*
997
+
* Windows are included in the list after successful
998
+
* open. So wait for closing these in-progress open
999
+
* windows in vas_allocate_window() which will be
1000
+
* done if the migration_in_progress is set.
1001
+
*/
1002
+
while (vcaps->nr_open_wins_progress) {
1003
+
mutex_unlock(&vas_pseries_mutex);
1004
+
msleep(10);
1005
+
mutex_lock(&vas_pseries_mutex);
1006
+
}
1007
+
mutex_unlock(&vas_pseries_mutex);
1016
1008
break;
1017
1009
case VAS_RESUME:
1010
+
mutex_lock(&vas_pseries_mutex);
1018
1011
atomic_set(&caps->nr_total_credits, new_nr_creds);
1019
1012
rc = reconfig_open_windows(vcaps, new_nr_creds, true);
1013
+
mutex_unlock(&vas_pseries_mutex);
1020
1014
break;
1021
1015
default:
1022
1016
/* should not happen */
···
1047
1011
goto out;
1048
1012
}
1049
1013
1014
+
pr_info("VAS migration event (%d) successful\n", action);
1015
+
1050
1016
out:
1051
-
mutex_unlock(&vas_pseries_mutex);
1052
1017
return rc;
1053
1018
}
1054
1019
+2
arch/powerpc/platforms/pseries/vas.h
+2
arch/powerpc/platforms/pseries/vas.h
···
91
91
struct vas_caps {
92
92
struct vas_cop_feat_caps caps;
93
93
struct list_head list; /* List of open windows */
94
+
int nr_open_wins_progress; /* Number of open windows in */
95
+
/* progress. Used in migration */
94
96
int nr_close_wins; /* closed windows in the hypervisor for DLPAR */
95
97
int nr_open_windows; /* Number of successful open windows */
96
98
u8 feat; /* Feature type */