From d2f51c50b941f89850c9a9561486938b71c0b9f8 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Thomas=20Hellstr=C3=B6m?= Date: Fri, 24 Nov 2023 16:33:45 +0100 Subject: [PATCH] drm/xe/vm: Fix ASID XA usage MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit xa_alloc_cyclic() returns 1 on successful allocation, if wrapping occurs, but the code incorrectly treats that as an error. Fix that. Also, xa_alloc_cyclic() requires xa_init_flags(..., XA_FLAGS_ALLOC), so fix that, and assuming we don't want a zero ASID, instead of using XA_FLAGS_ALLOC1, adjust the xa limits at alloc_cyclic time. v2: - On CONFIG_DRM_XE_DEBUG, Initialize the cyclic ASID allocation in such a way that the next allocated ASID will be the maximum one, and the one following will cause an ASID wrap, (all to have CI test high ASIDs and ASID wraps). v3: - Stricter return value checking from xa_alloc_cyclic() (Matthew Auld) Suggested-by: Ohad Sharabi Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/946 Signed-off-by: Thomas Hellström Reviewed-by: Ohad Sharabi #v1 Reviewed-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20231124153345.97385-5-thomas.hellstrom@linux.intel.com Signed-off-by: Rodrigo Vivi --- drivers/gpu/drm/xe/xe_device.c | 15 ++++++++++++++- drivers/gpu/drm/xe/xe_vm.c | 5 +++-- 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c index 8be765adf702d..d60379d844d2a 100644 --- a/drivers/gpu/drm/xe/xe_device.c +++ b/drivers/gpu/drm/xe/xe_device.c @@ -230,7 +230,20 @@ struct xe_device *xe_device_create(struct pci_dev *pdev, init_waitqueue_head(&xe->ufence_wq); drmm_mutex_init(&xe->drm, &xe->usm.lock); - xa_init_flags(&xe->usm.asid_to_vm, XA_FLAGS_ALLOC1); + xa_init_flags(&xe->usm.asid_to_vm, XA_FLAGS_ALLOC); + + if (IS_ENABLED(CONFIG_DRM_XE_DEBUG)) { + /* Trigger a large asid and an early asid wrap. */ + u32 asid; + + BUILD_BUG_ON(XE_MAX_ASID < 2); + err = xa_alloc_cyclic(&xe->usm.asid_to_vm, &asid, NULL, + XA_LIMIT(XE_MAX_ASID - 2, XE_MAX_ASID - 1), + &xe->usm.next_asid, GFP_KERNEL); + drm_WARN_ON(&xe->drm, err); + if (err >= 0) + xa_erase(&xe->usm.asid_to_vm, asid); + } drmm_mutex_init(&xe->drm, &xe->persistent_engines.lock); INIT_LIST_HEAD(&xe->persistent_engines.list); diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c index 1b4d340d06047..7c0ae43731803 100644 --- a/drivers/gpu/drm/xe/xe_vm.c +++ b/drivers/gpu/drm/xe/xe_vm.c @@ -1996,13 +1996,14 @@ int xe_vm_create_ioctl(struct drm_device *dev, void *data, if (xe->info.has_asid) { mutex_lock(&xe->usm.lock); err = xa_alloc_cyclic(&xe->usm.asid_to_vm, &asid, vm, - XA_LIMIT(0, XE_MAX_ASID - 1), + XA_LIMIT(1, XE_MAX_ASID - 1), &xe->usm.next_asid, GFP_KERNEL); mutex_unlock(&xe->usm.lock); - if (err) { + if (err < 0) { xe_vm_close_and_put(vm); return err; } + err = 0; vm->usm.asid = asid; } -- 2.30.2