diff options
| -rw-r--r-- | drivers/misc/cxl/cxl.h | 5 | ||||
| -rw-r--r-- | drivers/misc/cxl/main.c | 3 | ||||
| -rw-r--r-- | drivers/misc/cxl/pci.c | 11 | ||||
| -rw-r--r-- | drivers/misc/cxl/vphb.c | 18 |
4 files changed, 27 insertions, 10 deletions
diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h index 6c722d96b775..79e60ec70bd3 100644 --- a/drivers/misc/cxl/cxl.h +++ b/drivers/misc/cxl/cxl.h @@ -418,8 +418,9 @@ struct cxl_afu { struct dentry *debugfs; struct mutex contexts_lock; spinlock_t afu_cntl_lock; - /* Used to block access to AFU config space while deconfigured */ - struct rw_semaphore configured_rwsem; + + /* -1: AFU deconfigured/locked, >= 0: number of readers */ + atomic_t configured_state; /* AFU error buffer fields and bin attribute for sysfs */ u64 eb_len, eb_offset; diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c index 2a6bf1d0a3a4..cc1706a92ace 100644 --- a/drivers/misc/cxl/main.c +++ b/drivers/misc/cxl/main.c @@ -268,8 +268,7 @@ struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice) idr_init(&afu->contexts_idr); mutex_init(&afu->contexts_lock); spin_lock_init(&afu->afu_cntl_lock); - init_rwsem(&afu->configured_rwsem); - down_write(&afu->configured_rwsem); + atomic_set(&afu->configured_state, -1); afu->prefault_mode = CXL_PREFAULT_NONE; afu->irqs_max = afu->adapter->user_irqs; diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index cca938845ffd..91f645992c94 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -1129,7 +1129,7 @@ static int pci_configure_afu(struct cxl_afu *afu, struct cxl *adapter, struct pc if ((rc = cxl_native_register_psl_irq(afu))) goto err2; - up_write(&afu->configured_rwsem); + atomic_set(&afu->configured_state, 0); return 0; err2: @@ -1142,7 +1142,14 @@ err1: static void pci_deconfigure_afu(struct cxl_afu *afu) { - down_write(&afu->configured_rwsem); + /* + * It's okay to deconfigure when AFU is already locked, otherwise wait + * until there are no readers + */ + if (atomic_read(&afu->configured_state) != -1) { + while (atomic_cmpxchg(&afu->configured_state, 0, -1) != -1) + schedule(); + } cxl_native_release_psl_irq(afu); if (afu->adapter->native->sl_ops->release_serr_irq) afu->adapter->native->sl_ops->release_serr_irq(afu); diff --git a/drivers/misc/cxl/vphb.c b/drivers/misc/cxl/vphb.c index 639a343b7836..512a4897dbf6 100644 --- a/drivers/misc/cxl/vphb.c +++ b/drivers/misc/cxl/vphb.c @@ -83,6 +83,16 @@ static inline struct cxl_afu *pci_bus_to_afu(struct pci_bus *bus) return phb ? phb->private_data : NULL; } +static void cxl_afu_configured_put(struct cxl_afu *afu) +{ + atomic_dec_if_positive(&afu->configured_state); +} + +static bool cxl_afu_configured_get(struct cxl_afu *afu) +{ + return atomic_inc_unless_negative(&afu->configured_state); +} + static inline int cxl_pcie_config_info(struct pci_bus *bus, unsigned int devfn, struct cxl_afu *afu, int *_record) { @@ -107,7 +117,7 @@ static int cxl_pcie_read_config(struct pci_bus *bus, unsigned int devfn, afu = pci_bus_to_afu(bus); /* Grab a reader lock on afu. */ - if (afu == NULL || !down_read_trylock(&afu->configured_rwsem)) + if (afu == NULL || !cxl_afu_configured_get(afu)) return PCIBIOS_DEVICE_NOT_FOUND; rc = cxl_pcie_config_info(bus, devfn, afu, &record); @@ -132,7 +142,7 @@ static int cxl_pcie_read_config(struct pci_bus *bus, unsigned int devfn, } out: - up_read(&afu->configured_rwsem); + cxl_afu_configured_put(afu); return rc ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL; } @@ -144,7 +154,7 @@ static int cxl_pcie_write_config(struct pci_bus *bus, unsigned int devfn, afu = pci_bus_to_afu(bus); /* Grab a reader lock on afu. */ - if (afu == NULL || !down_read_trylock(&afu->configured_rwsem)) + if (afu == NULL || !cxl_afu_configured_get(afu)) return PCIBIOS_DEVICE_NOT_FOUND; rc = cxl_pcie_config_info(bus, devfn, afu, &record); @@ -166,7 +176,7 @@ static int cxl_pcie_write_config(struct pci_bus *bus, unsigned int devfn, } out: - up_read(&afu->configured_rwsem); + cxl_afu_configured_put(afu); return rc ? PCIBIOS_SET_FAILED : PCIBIOS_SUCCESSFUL; } |