diff options
Diffstat (limited to 'drivers/misc/cxl/main.c')
| -rw-r--r-- | drivers/misc/cxl/main.c | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c index d9be23b24aa3..62e0dfb5f15b 100644 --- a/drivers/misc/cxl/main.c +++ b/drivers/misc/cxl/main.c @@ -243,8 +243,10 @@ struct cxl *cxl_alloc_adapter(void) if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num)) goto err2; - return adapter; + /* start with context lock taken */ + atomic_set(&adapter->contexts_num, -1); + return adapter; err2: cxl_remove_adapter_nr(adapter); err1: @@ -286,6 +288,44 @@ int cxl_afu_select_best_mode(struct cxl_afu *afu) return 0; } +int cxl_adapter_context_get(struct cxl *adapter) +{ + int rc; + + rc = atomic_inc_unless_negative(&adapter->contexts_num); + return rc >= 0 ? 0 : -EBUSY; +} + +void cxl_adapter_context_put(struct cxl *adapter) +{ + atomic_dec_if_positive(&adapter->contexts_num); +} + +int cxl_adapter_context_lock(struct cxl *adapter) +{ + int rc; + /* no active contexts -> contexts_num == 0 */ + rc = atomic_cmpxchg(&adapter->contexts_num, 0, -1); + return rc ? -EBUSY : 0; +} + +void cxl_adapter_context_unlock(struct cxl *adapter) +{ + int val = atomic_cmpxchg(&adapter->contexts_num, -1, 0); + + /* + * contexts lock taken -> contexts_num == -1 + * If not true then show a warning and force reset the lock. + * This will happen when context_unlock was requested without + * doing a context_lock. + */ + if (val != -1) { + atomic_set(&adapter->contexts_num, 0); + WARN(1, "Adapter context unlocked with %d active contexts", + val); + } +} + static int __init init_cxl(void) { int rc = 0; |