From 5a218ceba7b64f506bf4f004b04bb457c1805a62 Mon Sep 17 00:00:00 2001 From: Carlos Chinea Date: Wed, 4 Apr 2012 14:11:45 +0300 Subject: [PATCH 1/6] HSI: hsi: Rework hsi_controller release Use the proper release mechanism for hsi_controller and hsi_ports structures. Free the structures through their associated device release callbacks. Signed-off-by: Carlos Chinea Acked-by: Greg Kroah-Hartman Acked-by: Linus Walleij --- drivers/hsi/hsi.c | 108 ++++++++++++++++++++++++---------------- include/linux/hsi/hsi.h | 6 +-- 2 files changed, 69 insertions(+), 45 deletions(-) diff --git a/drivers/hsi/hsi.c b/drivers/hsi/hsi.c index 4e2d79b79334..c17d12ca8e7f 100644 --- a/drivers/hsi/hsi.c +++ b/drivers/hsi/hsi.c @@ -140,12 +140,17 @@ static int hsi_remove_port(struct device *dev, void *data __maybe_unused) return 0; } -static void hsi_controller_release(struct device *dev __maybe_unused) +static void hsi_controller_release(struct device *dev) { + struct hsi_controller *hsi = to_hsi_controller(dev); + + kfree(hsi->port); + kfree(hsi); } -static void hsi_port_release(struct device *dev __maybe_unused) +static void hsi_port_release(struct device *dev) { + kfree(to_hsi_port(dev)); } /** @@ -172,18 +177,14 @@ int hsi_register_controller(struct hsi_controller *hsi) hsi->device.type = &hsi_ctrl; hsi->device.bus = &hsi_bus_type; - hsi->device.release = hsi_controller_release; - err = device_register(&hsi->device); + err = device_add(&hsi->device); if (err < 0) return err; for (i = 0; i < hsi->num_ports; i++) { - hsi->port[i].device.parent = &hsi->device; - hsi->port[i].device.bus = &hsi_bus_type; - hsi->port[i].device.release = hsi_port_release; - hsi->port[i].device.type = &hsi_port; - INIT_LIST_HEAD(&hsi->port[i].clients); - spin_lock_init(&hsi->port[i].clock); - err = device_register(&hsi->port[i].device); + hsi->port[i]->device.parent = &hsi->device; + hsi->port[i]->device.bus = &hsi_bus_type; + hsi->port[i]->device.type = &hsi_port; + err = device_add(&hsi->port[i]->device); if (err < 0) goto out; } @@ -192,7 +193,9 @@ int hsi_register_controller(struct hsi_controller *hsi) return 0; out: - hsi_unregister_controller(hsi); + while (i-- > 0) + device_del(&hsi->port[i]->device); + device_del(&hsi->device); return err; } @@ -222,6 +225,29 @@ static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused) return 0; } +/** + * hsi_put_controller - Free an HSI controller + * + * @hsi: Pointer to the HSI controller to freed + * + * HSI controller drivers should only use this function if they need + * to free their allocated hsi_controller structures before a successful + * call to hsi_register_controller. Other use is not allowed. + */ +void hsi_put_controller(struct hsi_controller *hsi) +{ + unsigned int i; + + if (!hsi) + return; + + for (i = 0; i < hsi->num_ports; i++) + if (hsi->port && hsi->port[i]) + put_device(&hsi->port[i]->device); + put_device(&hsi->device); +} +EXPORT_SYMBOL_GPL(hsi_put_controller); + /** * hsi_alloc_controller - Allocate an HSI controller and its ports * @n_ports: Number of ports on the HSI controller @@ -232,54 +258,52 @@ static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused) struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags) { struct hsi_controller *hsi; - struct hsi_port *port; + struct hsi_port **port; unsigned int i; if (!n_ports) return NULL; - port = kzalloc(sizeof(*port)*n_ports, flags); - if (!port) - return NULL; hsi = kzalloc(sizeof(*hsi), flags); if (!hsi) - goto out; - for (i = 0; i < n_ports; i++) { - dev_set_name(&port[i].device, "port%d", i); - port[i].num = i; - port[i].async = hsi_dummy_msg; - port[i].setup = hsi_dummy_cl; - port[i].flush = hsi_dummy_cl; - port[i].start_tx = hsi_dummy_cl; - port[i].stop_tx = hsi_dummy_cl; - port[i].release = hsi_dummy_cl; - mutex_init(&port[i].lock); + return NULL; + port = kzalloc(sizeof(*port)*n_ports, flags); + if (!port) { + kfree(hsi); + return NULL; } hsi->num_ports = n_ports; hsi->port = port; + hsi->device.release = hsi_controller_release; + device_initialize(&hsi->device); + + for (i = 0; i < n_ports; i++) { + port[i] = kzalloc(sizeof(**port), flags); + if (port[i] == NULL) + goto out; + port[i]->num = i; + port[i]->async = hsi_dummy_msg; + port[i]->setup = hsi_dummy_cl; + port[i]->flush = hsi_dummy_cl; + port[i]->start_tx = hsi_dummy_cl; + port[i]->stop_tx = hsi_dummy_cl; + port[i]->release = hsi_dummy_cl; + mutex_init(&port[i]->lock); + INIT_LIST_HEAD(&hsi->port[i]->clients); + spin_lock_init(&hsi->port[i]->clock); + dev_set_name(&port[i]->device, "port%d", i); + hsi->port[i]->device.release = hsi_port_release; + device_initialize(&hsi->port[i]->device); + } return hsi; out: - kfree(port); + hsi_put_controller(hsi); return NULL; } EXPORT_SYMBOL_GPL(hsi_alloc_controller); -/** - * hsi_free_controller - Free an HSI controller - * @hsi: Pointer to HSI controller - */ -void hsi_free_controller(struct hsi_controller *hsi) -{ - if (!hsi) - return; - - kfree(hsi->port); - kfree(hsi); -} -EXPORT_SYMBOL_GPL(hsi_free_controller); - /** * hsi_free_msg - Free an HSI message * @msg: Pointer to the HSI message diff --git a/include/linux/hsi/hsi.h b/include/linux/hsi/hsi.h index 4b178067f405..7f3b7262a2b6 100644 --- a/include/linux/hsi/hsi.h +++ b/include/linux/hsi/hsi.h @@ -270,13 +270,13 @@ struct hsi_controller { struct module *owner; unsigned int id; unsigned int num_ports; - struct hsi_port *port; + struct hsi_port **port; }; #define to_hsi_controller(dev) container_of(dev, struct hsi_controller, device) struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags); -void hsi_free_controller(struct hsi_controller *hsi); +void hsi_put_controller(struct hsi_controller *hsi); int hsi_register_controller(struct hsi_controller *hsi); void hsi_unregister_controller(struct hsi_controller *hsi); @@ -294,7 +294,7 @@ static inline void *hsi_controller_drvdata(struct hsi_controller *hsi) static inline struct hsi_port *hsi_find_port_num(struct hsi_controller *hsi, unsigned int num) { - return (num < hsi->num_ports) ? &hsi->port[num] : NULL; + return (num < hsi->num_ports) ? hsi->port[num] : NULL; } /* From 90e41f9dc75b47ab94e2191e4c86aa8259699a33 Mon Sep 17 00:00:00 2001 From: Carlos Chinea Date: Wed, 11 Apr 2012 11:01:11 +0300 Subject: [PATCH 2/6] HSI: hsi: Fix error path cleanup on client registration HSI client structure should be freed on error path after calling device_registration by dropping a reference to it. Signed-off-by: Carlos Chinea Acked-by: Greg Kroah-Hartman Acked-by: Linus Walleij --- drivers/hsi/hsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hsi/hsi.c b/drivers/hsi/hsi.c index c17d12ca8e7f..5c76a36419d4 100644 --- a/drivers/hsi/hsi.c +++ b/drivers/hsi/hsi.c @@ -100,7 +100,7 @@ static void hsi_new_client(struct hsi_port *port, struct hsi_board_info *info) cl->device.archdata = *info->archdata; if (device_register(&cl->device) < 0) { pr_err("hsi: failed to register client: %s\n", info->name); - kfree(cl); + put_device(&cl->device); } } From 6f02b9e9b44a3bfc0046da3ff2707dae0b5e2f30 Mon Sep 17 00:00:00 2001 From: Carlos Chinea Date: Tue, 10 Apr 2012 15:11:24 +0300 Subject: [PATCH 3/6] HSI: hsi: Remove controllers and ports from the bus HSI controllers and ports do not belong to the HSI bus. Those devices are not supposed to have a driver attached to them. Signed-off-by: Carlos Chinea Acked-by: Greg Kroah-Hartman Acked-by: Linus Walleij --- drivers/hsi/hsi.c | 20 +------------------- 1 file changed, 1 insertion(+), 19 deletions(-) diff --git a/drivers/hsi/hsi.c b/drivers/hsi/hsi.c index 5c76a36419d4..cec1f0c04557 100644 --- a/drivers/hsi/hsi.c +++ b/drivers/hsi/hsi.c @@ -29,18 +29,6 @@ #include #include "hsi_core.h" -static struct device_type hsi_ctrl = { - .name = "hsi_controller", -}; - -static struct device_type hsi_cl = { - .name = "hsi_client", -}; - -static struct device_type hsi_port = { - .name = "hsi_port", -}; - static ssize_t modalias_show(struct device *dev, struct device_attribute *a __maybe_unused, char *buf) { @@ -54,8 +42,7 @@ static struct device_attribute hsi_bus_dev_attrs[] = { static int hsi_bus_uevent(struct device *dev, struct kobj_uevent_env *env) { - if (dev->type == &hsi_cl) - add_uevent_var(env, "MODALIAS=hsi:%s", dev_name(dev)); + add_uevent_var(env, "MODALIAS=hsi:%s", dev_name(dev)); return 0; } @@ -85,7 +72,6 @@ static void hsi_new_client(struct hsi_port *port, struct hsi_board_info *info) cl = kzalloc(sizeof(*cl), GFP_KERNEL); if (!cl) return; - cl->device.type = &hsi_cl; cl->tx_cfg = info->tx_cfg; cl->rx_cfg = info->rx_cfg; cl->device.bus = &hsi_bus_type; @@ -175,15 +161,11 @@ int hsi_register_controller(struct hsi_controller *hsi) unsigned int i; int err; - hsi->device.type = &hsi_ctrl; - hsi->device.bus = &hsi_bus_type; err = device_add(&hsi->device); if (err < 0) return err; for (i = 0; i < hsi->num_ports; i++) { hsi->port[i]->device.parent = &hsi->device; - hsi->port[i]->device.bus = &hsi_bus_type; - hsi->port[i]->device.type = &hsi_port; err = device_add(&hsi->port[i]->device); if (err < 0) goto out; From ec1c56ff813a198d656d4aa42e5de03e45751bf8 Mon Sep 17 00:00:00 2001 From: Carlos Chinea Date: Wed, 11 Apr 2012 10:55:53 +0300 Subject: [PATCH 4/6] HSI: hsi: Rework hsi_event interface Remove custom hack and make use of the notifier chain interfaces for delivering events from the ports to their associated clients. Clients that want to receive port events need to register their callbacks using hsi_register_port_event(). The callbacks can be called in interrupt context. Use hsi_unregestier_port_event() to undo the registration. Signed-off-by: Carlos Chinea Acked-by: Greg Kroah-Hartman Acked-by: Linus Walleij --- drivers/hsi/hsi.c | 101 +++++++++++++++++++++------------------- include/linux/hsi/hsi.h | 25 +++++----- 2 files changed, 68 insertions(+), 58 deletions(-) diff --git a/drivers/hsi/hsi.c b/drivers/hsi/hsi.c index cec1f0c04557..2d58f939d27f 100644 --- a/drivers/hsi/hsi.c +++ b/drivers/hsi/hsi.c @@ -21,12 +21,11 @@ */ #include #include -#include #include -#include #include #include #include +#include #include "hsi_core.h" static ssize_t modalias_show(struct device *dev, @@ -67,7 +66,6 @@ static void hsi_client_release(struct device *dev) static void hsi_new_client(struct hsi_port *port, struct hsi_board_info *info) { struct hsi_client *cl; - unsigned long flags; cl = kzalloc(sizeof(*cl), GFP_KERNEL); if (!cl) @@ -79,9 +77,6 @@ static void hsi_new_client(struct hsi_port *port, struct hsi_board_info *info) cl->device.release = hsi_client_release; dev_set_name(&cl->device, info->name); cl->device.platform_data = info->platform_data; - spin_lock_irqsave(&port->clock, flags); - list_add_tail(&cl->link, &port->clients); - spin_unlock_irqrestore(&port->clock, flags); if (info->archdata) cl->device.archdata = *info->archdata; if (device_register(&cl->device) < 0) { @@ -106,13 +101,6 @@ static void hsi_scan_board_info(struct hsi_controller *hsi) static int hsi_remove_client(struct device *dev, void *data __maybe_unused) { - struct hsi_client *cl = to_hsi_client(dev); - struct hsi_port *port = to_hsi_port(dev->parent); - unsigned long flags; - - spin_lock_irqsave(&port->clock, flags); - list_del(&cl->link); - spin_unlock_irqrestore(&port->clock, flags); device_unregister(dev); return 0; @@ -271,8 +259,7 @@ struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags) port[i]->stop_tx = hsi_dummy_cl; port[i]->release = hsi_dummy_cl; mutex_init(&port[i]->lock); - INIT_LIST_HEAD(&hsi->port[i]->clients); - spin_lock_init(&hsi->port[i]->clock); + ATOMIC_INIT_NOTIFIER_HEAD(&port[i]->n_head); dev_set_name(&port[i]->device, "port%d", i); hsi->port[i]->device.release = hsi_port_release; device_initialize(&hsi->port[i]->device); @@ -420,37 +407,67 @@ void hsi_release_port(struct hsi_client *cl) } EXPORT_SYMBOL_GPL(hsi_release_port); -static int hsi_start_rx(struct hsi_client *cl, void *data __maybe_unused) +static int hsi_event_notifier_call(struct notifier_block *nb, + unsigned long event, void *data __maybe_unused) { - if (cl->hsi_start_rx) - (*cl->hsi_start_rx)(cl); + struct hsi_client *cl = container_of(nb, struct hsi_client, nb); + + (*cl->ehandler)(cl, event); return 0; } -static int hsi_stop_rx(struct hsi_client *cl, void *data __maybe_unused) +/** + * hsi_register_port_event - Register a client to receive port events + * @cl: HSI client that wants to receive port events + * @cb: Event handler callback + * + * Clients should register a callback to be able to receive + * events from the ports. Registration should happen after + * claiming the port. + * The handler can be called in interrupt context. + * + * Returns -errno on error, or 0 on success. + */ +int hsi_register_port_event(struct hsi_client *cl, + void (*handler)(struct hsi_client *, unsigned long)) { - if (cl->hsi_stop_rx) - (*cl->hsi_stop_rx)(cl); + struct hsi_port *port = hsi_get_port(cl); - return 0; + if (!handler || cl->ehandler) + return -EINVAL; + if (!hsi_port_claimed(cl)) + return -EACCES; + cl->ehandler = handler; + cl->nb.notifier_call = hsi_event_notifier_call; + + return atomic_notifier_chain_register(&port->n_head, &cl->nb); } +EXPORT_SYMBOL_GPL(hsi_register_port_event); -static int hsi_port_for_each_client(struct hsi_port *port, void *data, - int (*fn)(struct hsi_client *cl, void *data)) +/** + * hsi_unregister_port_event - Stop receiving port events for a client + * @cl: HSI client that wants to stop receiving port events + * + * Clients should call this function before releasing their associated + * port. + * + * Returns -errno on error, or 0 on success. + */ +int hsi_unregister_port_event(struct hsi_client *cl) { - struct hsi_client *cl; + struct hsi_port *port = hsi_get_port(cl); + int err; - spin_lock(&port->clock); - list_for_each_entry(cl, &port->clients, link) { - spin_unlock(&port->clock); - (*fn)(cl, data); - spin_lock(&port->clock); - } - spin_unlock(&port->clock); + WARN_ON(!hsi_port_claimed(cl)); - return 0; + err = atomic_notifier_chain_unregister(&port->n_head, &cl->nb); + if (!err) + cl->ehandler = NULL; + + return err; } +EXPORT_SYMBOL_GPL(hsi_unregister_port_event); /** * hsi_event -Notifies clients about port events @@ -464,22 +481,12 @@ static int hsi_port_for_each_client(struct hsi_port *port, void *data, * Events: * HSI_EVENT_START_RX - Incoming wake line high * HSI_EVENT_STOP_RX - Incoming wake line down + * + * Returns -errno on error, or 0 on success. */ -void hsi_event(struct hsi_port *port, unsigned int event) +int hsi_event(struct hsi_port *port, unsigned long event) { - int (*fn)(struct hsi_client *cl, void *data); - - switch (event) { - case HSI_EVENT_START_RX: - fn = hsi_start_rx; - break; - case HSI_EVENT_STOP_RX: - fn = hsi_stop_rx; - break; - default: - return; - } - hsi_port_for_each_client(port, NULL, fn); + return atomic_notifier_call_chain(&port->n_head, event, NULL); } EXPORT_SYMBOL_GPL(hsi_event); diff --git a/include/linux/hsi/hsi.h b/include/linux/hsi/hsi.h index 7f3b7262a2b6..56fae865e272 100644 --- a/include/linux/hsi/hsi.h +++ b/include/linux/hsi/hsi.h @@ -26,9 +26,9 @@ #include #include #include -#include #include #include +#include /* HSI message ttype */ #define HSI_MSG_READ 0 @@ -121,18 +121,18 @@ static inline int hsi_register_board_info(struct hsi_board_info const *info, * @device: Driver model representation of the device * @tx_cfg: HSI TX configuration * @rx_cfg: HSI RX configuration - * @hsi_start_rx: Called after incoming wake line goes high - * @hsi_stop_rx: Called after incoming wake line goes low + * @e_handler: Callback for handling port events (RX Wake High/Low) + * @pclaimed: Keeps tracks if the clients claimed its associated HSI port + * @nb: Notifier block for port events */ struct hsi_client { struct device device; struct hsi_config tx_cfg; struct hsi_config rx_cfg; - void (*hsi_start_rx)(struct hsi_client *cl); - void (*hsi_stop_rx)(struct hsi_client *cl); /* private: */ + void (*ehandler)(struct hsi_client *, unsigned long); unsigned int pclaimed:1; - struct list_head link; + struct notifier_block nb; }; #define to_hsi_client(dev) container_of(dev, struct hsi_client, device) @@ -147,6 +147,10 @@ static inline void *hsi_client_drvdata(struct hsi_client *cl) return dev_get_drvdata(&cl->device); } +int hsi_register_port_event(struct hsi_client *cl, + void (*handler)(struct hsi_client *, unsigned long)); +int hsi_unregister_port_event(struct hsi_client *cl); + /** * struct hsi_client_driver - Driver associated to an HSI client * @driver: Driver model representation of the driver @@ -214,8 +218,7 @@ void hsi_free_msg(struct hsi_msg *msg); * @start_tx: Callback to inform that a client wants to TX data * @stop_tx: Callback to inform that a client no longer wishes to TX data * @release: Callback to inform that a client no longer uses the port - * @clients: List of hsi_clients using the port. - * @clock: Lock to serialize access to the clients list. + * @n_head: Notifier chain for signaling port events to the clients. */ struct hsi_port { struct device device; @@ -231,14 +234,14 @@ struct hsi_port { int (*start_tx)(struct hsi_client *cl); int (*stop_tx)(struct hsi_client *cl); int (*release)(struct hsi_client *cl); - struct list_head clients; - spinlock_t clock; + /* private */ + struct atomic_notifier_head n_head; }; #define to_hsi_port(dev) container_of(dev, struct hsi_port, device) #define hsi_get_port(cl) to_hsi_port((cl)->device.parent) -void hsi_event(struct hsi_port *port, unsigned int event); +int hsi_event(struct hsi_port *port, unsigned long event); int hsi_claim_port(struct hsi_client *cl, unsigned int share); void hsi_release_port(struct hsi_client *cl); From fdadb6e9a5cf65c7662b2ca817856f187d05ab7d Mon Sep 17 00:00:00 2001 From: Carlos Chinea Date: Fri, 13 Apr 2012 16:03:03 +0300 Subject: [PATCH 5/6] HSI: hsi_char: Remove max_data_size from sysfs Remove max_data_size sysfs entry. Otherwise is possible to have a buffer overrun if its value is increased after the device is open. Signed-off-by: Carlos Chinea Acked-by: Greg Kroah-Hartman Acked-by: Linus Walleij --- drivers/hsi/clients/hsi_char.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hsi/clients/hsi_char.c b/drivers/hsi/clients/hsi_char.c index 88a050df2389..3ad91f6447d8 100644 --- a/drivers/hsi/clients/hsi_char.c +++ b/drivers/hsi/clients/hsi_char.c @@ -123,7 +123,7 @@ struct hsc_client_data { static unsigned int hsc_major; /* Maximum buffer size that hsi_char will accept from userspace */ static unsigned int max_data_size = 0x1000; -module_param(max_data_size, uint, S_IRUSR | S_IWUSR); +module_param(max_data_size, uint, 0); MODULE_PARM_DESC(max_data_size, "max read/write data size [4,8..65536] (^2)"); static void hsc_add_tail(struct hsc_channel *channel, struct hsi_msg *msg, From 24b7099af71232b7568acd74770e6eb8f174f5d6 Mon Sep 17 00:00:00 2001 From: Carlos Chinea Date: Fri, 13 Apr 2012 15:55:13 +0300 Subject: [PATCH 6/6] HSI: Add HSI ABI documentation Adds sysfs HSI framework documentation Signed-off-by: Carlos Chinea Acked-by: Greg Kroah-Hartman Acked-by: Linus Walleij --- Documentation/ABI/testing/sysfs-bus-hsi | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-hsi diff --git a/Documentation/ABI/testing/sysfs-bus-hsi b/Documentation/ABI/testing/sysfs-bus-hsi new file mode 100644 index 000000000000..1b1b282a99e1 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-hsi @@ -0,0 +1,19 @@ +What: /sys/bus/hsi +Date: April 2012 +KernelVersion: 3.4 +Contact: Carlos Chinea +Description: + High Speed Synchronous Serial Interface (HSI) is a + serial interface mainly used for connecting application + engines (APE) with cellular modem engines (CMT) in cellular + handsets. + The bus will be populated with devices (hsi_clients) representing + the protocols available in the system. Bus drivers implement + those protocols. + +What: /sys/bus/hsi/devices/.../modalias +Date: April 2012 +KernelVersion: 3.4 +Contact: Carlos Chinea +Description: Stores the same MODALIAS value emitted by uevent + Format: hsi: