alistair23-linux/drivers/staging/greybus/greybus.h
Johan Hovold 3e136cc9e0 greybus: operation/esx: fix message-cancellation lifetime bugs
The current host-controller message-cancellation implementation suffer
from a lifetime bug as dynamically allocated URBs would complete and be
deallocated while being unlinked as part of cancellation.

The current locking is also insufficient to prevent the related race
where the URB is deallocated before being unlinked.

Fix this by pushing the cancellation implementation from greybus core
down to the host-controller drivers, and replace the "cookie" pointer
with a hcpriv field that those drivers can use to maintain their state
with the required locking and reference counting in place.

Specifically the drivers need to acquire a reference to the URB under a
lock before calling usb_kill_urb as part of cancellation.

Note that this also removes the insufficient gb_message_mutex, which
also effectively prevented us from implementing support for submissions
from atomic context.

Instead the host-controller drivers must now explicitly make sure that
the pre-allocated URBs are not reused while cancellation is in progress.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2015-07-01 16:43:02 -07:00

204 lines
5.8 KiB
C

/*
* Greybus driver and device API
*
* Copyright 2014-2015 Google Inc.
* Copyright 2014-2015 Linaro Ltd.
*
* Released under the GPLv2 only.
*/
#ifndef __LINUX_GREYBUS_H
#define __LINUX_GREYBUS_H
#ifdef __KERNEL__
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/idr.h>
#include "kernel_ver.h"
#include "greybus_id.h"
#include "greybus_manifest.h"
#include "greybus_protocols.h"
#include "manifest.h"
#include "endo.h"
#include "svc.h"
#include "module.h"
#include "control.h"
#include "interface.h"
#include "bundle.h"
#include "connection.h"
#include "protocol.h"
#include "operation.h"
/* Matches up with the Greybus Protocol specification document */
#define GREYBUS_VERSION_MAJOR 0x00
#define GREYBUS_VERSION_MINOR 0x01
#define GREYBUS_DEVICE_ID_MATCH_DEVICE \
(GREYBUS_DEVICE_ID_MATCH_VENDOR | GREYBUS_DEVICE_ID_MATCH_PRODUCT)
#define GREYBUS_DEVICE(v, p) \
.match_flags = GREYBUS_DEVICE_ID_MATCH_DEVICE, \
.vendor = (v), \
.product = (p),
#define GREYBUS_DEVICE_SERIAL(s) \
.match_flags = GREYBUS_DEVICE_ID_MATCH_SERIAL, \
.serial_number = (s),
/* XXX I couldn't get my Kconfig file to be noticed for out-of-tree build */
#ifndef CONFIG_CPORT_ID_MAX
#define CONFIG_CPORT_ID_MAX 128
#endif /* !CONFIG_CPORT_ID_MAX */
/* Maximum number of CPorts usable by a host device */
/* XXX This should really be determined by the AP module manifest */
#define CPORT_ID_MAX CONFIG_CPORT_ID_MAX
#define CPORT_ID_BAD U16_MAX /* UniPro max id is 4095 */
/* For SP1 hardware, we are going to "hardcode" each device to have all logical
* blocks in order to be able to address them as one unified "unit". Then
* higher up layers will then be able to talk to them as one logical block and
* properly know how they are hooked together (i.e. which i2c port is on the
* same module as the gpio pins, etc.)
*
* So, put the "private" data structures here in greybus.h and link to them off
* of the "main" gb_module structure.
*/
struct greybus_host_device;
struct svc_msg;
/* Greybus "Host driver" structure, needed by a host controller driver to be
* able to handle both SVC control as well as "real" greybus messages
*/
struct greybus_host_driver {
size_t hd_priv_size;
int (*message_send)(struct greybus_host_device *hd, u16 dest_cport_id,
struct gb_message *message, gfp_t gfp_mask);
void (*message_cancel)(struct gb_message *message);
int (*submit_svc)(struct svc_msg *svc_msg,
struct greybus_host_device *hd);
};
struct greybus_host_device {
struct kref kref;
struct device *parent;
const struct greybus_host_driver *driver;
struct list_head interfaces;
struct list_head connections;
struct ida cport_id_map;
u8 device_id;
/* Host device buffer constraints */
size_t buffer_size_max;
struct gb_endo *endo;
/* Private data for the host driver */
unsigned long hd_priv[0] __aligned(sizeof(s64));
};
struct greybus_host_device *greybus_create_hd(struct greybus_host_driver *hd,
struct device *parent,
size_t buffer_size_max);
int greybus_endo_setup(struct greybus_host_device *hd, u16 endo_id,
u8 ap_intf_id);
void greybus_remove_hd(struct greybus_host_device *hd);
struct greybus_driver {
const char *name;
int (*probe)(struct gb_bundle *bundle,
const struct greybus_bundle_id *id);
void (*disconnect)(struct gb_bundle *bundle);
int (*suspend)(struct gb_bundle *bundle, pm_message_t message);
int (*resume)(struct gb_bundle *bundle);
const struct greybus_bundle_id *id_table;
struct device_driver driver;
};
#define to_greybus_driver(d) container_of(d, struct greybus_driver, driver)
/* Don't call these directly, use the module_greybus_driver() macro instead */
int greybus_register_driver(struct greybus_driver *driver,
struct module *module, const char *mod_name);
void greybus_deregister_driver(struct greybus_driver *driver);
/* define to get proper THIS_MODULE and KBUILD_MODNAME values */
#define greybus_register(driver) \
greybus_register_driver(driver, THIS_MODULE, KBUILD_MODNAME)
#define greybus_deregister(driver) \
greybus_deregister_driver(driver)
/**
* module_greybus_driver() - Helper macro for registering a Greybus driver
* @__greybus_driver: greybus_driver structure
*
* Helper macro for Greybus drivers to set up proper module init / exit
* functions. Replaces module_init() and module_exit() and keeps people from
* printing pointless things to the kernel log when their driver is loaded.
*/
#define module_greybus_driver(__greybus_driver) \
module_driver(__greybus_driver, greybus_register, greybus_deregister)
int greybus_disabled(void);
int greybus_svc_in(struct greybus_host_device *hd, u8 *data, int length);
int gb_ap_init(void);
void gb_ap_exit(void);
void gb_debugfs_init(void);
void gb_debugfs_cleanup(void);
struct dentry *gb_debugfs_get(void);
extern struct bus_type greybus_bus_type;
extern struct device_type greybus_endo_type;
extern struct device_type greybus_module_type;
extern struct device_type greybus_interface_type;
extern struct device_type greybus_bundle_type;
extern struct device_type greybus_connection_type;
static inline int is_gb_endo(const struct device *dev)
{
return dev->type == &greybus_endo_type;
}
static inline int is_gb_module(const struct device *dev)
{
return dev->type == &greybus_module_type;
}
static inline int is_gb_interface(const struct device *dev)
{
return dev->type == &greybus_interface_type;
}
static inline int is_gb_bundle(const struct device *dev)
{
return dev->type == &greybus_bundle_type;
}
static inline int is_gb_connection(const struct device *dev)
{
return dev->type == &greybus_connection_type;
}
static inline bool cport_id_valid(u16 cport_id)
{
return cport_id != CPORT_ID_BAD && cport_id <= CPORT_ID_MAX;
}
#endif /* __KERNEL__ */
#endif /* __LINUX_GREYBUS_H */