Commit 9edbc30b authored by Alexandre Bounine's avatar Alexandre Bounine Committed by Linus Torvalds
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rapidio: update enumerator registration mechanism



Update enumeration/discovery method registration mechanism to allow
loading enumeration/discovery methods before all mports are registered.

Existing statically linked RapidIO subsystem expects that all available
RapidIO mport devices are initialized and registered before the
enumeration/discovery method is registered.  Switching to loadable mport
device drivers creates situation when mport device driver can be loaded
after enumeration/discovery method is attached (e.g., loadable mport
driver in a system with statically linked RapidIO core and enumerator).
This also will happen in a system with hot-pluggable RapidIO controllers.

To remove the dependency on the initialization/registration order this
patch introduces enumeration/discovery registration mechanism that
supports arbitrary registration order of mports and enumerator/discovery
methods.

The following registration rules are implemented:
- only one enumeration/discovery method can be registered for given mport ID
  (including RIO_MPORT_ANY);
- when new enumeration/discovery methods tries to attach to the registered mport
  device, method with matching mport ID will replace a default method previously
  registered for given mport (if any);
- enumeration/discovery method with target ID=RIO_MPORT_ANY will be attached
  only to mports that do not have another enumerator attached to them;
- when new mport device is registered with RapidIO subsystem, registration
  routine searches for the enumeration/discovery method with the best matching
  mport ID;
Signed-off-by: default avatarAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@Prodrive.nl>
Cc: Micha Nelissen <micha.nelissen@Prodrive.nl>
Cc: Stef van Os <stef.van.os@Prodrive.nl>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e6161d64
......@@ -1162,6 +1162,7 @@ bail:
}
static struct rio_scan rio_scan_ops = {
.owner = THIS_MODULE,
.enumerate = rio_enum_mport,
.discover = rio_disc_mport,
};
......
......@@ -286,7 +286,6 @@ static ssize_t bus_scan_store(struct bus_type *bus, const char *buf,
size_t count)
{
long val;
struct rio_mport *port = NULL;
int rc;
if (kstrtol(buf, 0, &val) < 0)
......@@ -300,21 +299,7 @@ static ssize_t bus_scan_store(struct bus_type *bus, const char *buf,
if (val < 0 || val >= RIO_MAX_MPORTS)
return -EINVAL;
port = rio_find_mport((int)val);
if (!port) {
pr_debug("RIO: %s: mport_%d not available\n",
__func__, (int)val);
return -EINVAL;
}
if (!port->nscan)
return -EINVAL;
if (port->host_deviceid >= 0)
rc = port->nscan->enumerate(port, 0);
else
rc = port->nscan->discover(port, RIO_SCAN_ENUM_NO_WAIT);
rc = rio_mport_scan((int)val);
exit:
if (!rc)
rc = count;
......
......@@ -34,6 +34,7 @@ static LIST_HEAD(rio_devices);
static DEFINE_SPINLOCK(rio_global_list_lock);
static LIST_HEAD(rio_mports);
static LIST_HEAD(rio_scans);
static DEFINE_MUTEX(rio_mport_list_lock);
static unsigned char next_portid;
static DEFINE_SPINLOCK(rio_mmap_lock);
......@@ -1602,34 +1603,73 @@ found:
* rio_register_scan - enumeration/discovery method registration interface
* @mport_id: mport device ID for which fabric scan routine has to be set
* (RIO_MPORT_ANY = set for all available mports)
* @scan_ops: enumeration/discovery control structure
* @scan_ops: enumeration/discovery operations structure
*
* Registers enumeration/discovery operations with RapidIO subsystem and
* attaches it to the specified mport device (or all available mports
* if RIO_MPORT_ANY is specified).
*
* Assigns enumeration or discovery method to the specified mport device (or all
* available mports if RIO_MPORT_ANY is specified).
* Returns error if the mport already has an enumerator attached to it.
* In case of RIO_MPORT_ANY ignores ports with valid scan routines and returns
* an error if was unable to find at least one available mport.
* In case of RIO_MPORT_ANY skips mports with valid scan routines (no error).
*/
int rio_register_scan(int mport_id, struct rio_scan *scan_ops)
{
struct rio_mport *port;
int rc = -EBUSY;
struct rio_scan_node *scan;
int rc = 0;
mutex_lock(&rio_mport_list_lock);
list_for_each_entry(port, &rio_mports, node) {
if (port->id == mport_id || mport_id == RIO_MPORT_ANY) {
if (port->nscan && mport_id == RIO_MPORT_ANY)
continue;
else if (port->nscan)
break;
pr_debug("RIO: %s for mport_id=%d\n", __func__, mport_id);
port->nscan = scan_ops;
rc = 0;
if ((mport_id != RIO_MPORT_ANY && mport_id >= RIO_MAX_MPORTS) ||
!scan_ops)
return -EINVAL;
if (mport_id != RIO_MPORT_ANY)
break;
mutex_lock(&rio_mport_list_lock);
/*
* Check if there is another enumerator already registered for
* the same mport ID (including RIO_MPORT_ANY). Multiple enumerators
* for the same mport ID are not supported.
*/
list_for_each_entry(scan, &rio_scans, node) {
if (scan->mport_id == mport_id) {
rc = -EBUSY;
goto err_out;
}
}
/*
* Allocate and initialize new scan registration node.
*/
scan = kzalloc(sizeof(*scan), GFP_KERNEL);
if (!scan) {
rc = -ENOMEM;
goto err_out;
}
scan->mport_id = mport_id;
scan->ops = scan_ops;
/*
* Traverse the list of registered mports to attach this new scan.
*
* The new scan with matching mport ID overrides any previously attached
* scan assuming that old scan (if any) is the default one (based on the
* enumerator registration check above).
* If the new scan is the global one, it will be attached only to mports
* that do not have their own individual operations already attached.
*/
list_for_each_entry(port, &rio_mports, node) {
if (port->id == mport_id) {
port->nscan = scan_ops;
break;
} else if (mport_id == RIO_MPORT_ANY && !port->nscan)
port->nscan = scan_ops;
}
list_add_tail(&scan->node, &rio_scans);
err_out:
mutex_unlock(&rio_mport_list_lock);
return rc;
......@@ -1639,30 +1679,81 @@ EXPORT_SYMBOL_GPL(rio_register_scan);
/**
* rio_unregister_scan - removes enumeration/discovery method from mport
* @mport_id: mport device ID for which fabric scan routine has to be
* unregistered (RIO_MPORT_ANY = set for all available mports)
* unregistered (RIO_MPORT_ANY = apply to all mports that use
* the specified scan_ops)
* @scan_ops: enumeration/discovery operations structure
*
* Removes enumeration or discovery method assigned to the specified mport
* device (or all available mports if RIO_MPORT_ANY is specified).
* device. If RIO_MPORT_ANY is specified, removes the specified operations from
* all mports that have them attached.
*/
int rio_unregister_scan(int mport_id)
int rio_unregister_scan(int mport_id, struct rio_scan *scan_ops)
{
struct rio_mport *port;
struct rio_scan_node *scan;
pr_debug("RIO: %s for mport_id=%d\n", __func__, mport_id);
if (mport_id != RIO_MPORT_ANY && mport_id >= RIO_MAX_MPORTS)
return -EINVAL;
mutex_lock(&rio_mport_list_lock);
list_for_each_entry(port, &rio_mports, node) {
if (port->id == mport_id || mport_id == RIO_MPORT_ANY) {
if (port->nscan)
port->nscan = NULL;
if (mport_id != RIO_MPORT_ANY)
break;
list_for_each_entry(port, &rio_mports, node)
if (port->id == mport_id ||
(mport_id == RIO_MPORT_ANY && port->nscan == scan_ops))
port->nscan = NULL;
list_for_each_entry(scan, &rio_scans, node)
if (scan->mport_id == mport_id) {
list_del(&scan->node);
kfree(scan);
}
}
mutex_unlock(&rio_mport_list_lock);
return 0;
}
EXPORT_SYMBOL_GPL(rio_unregister_scan);
/**
* rio_mport_scan - execute enumeration/discovery on the specified mport
* @mport_id: number (ID) of mport device
*/
int rio_mport_scan(int mport_id)
{
struct rio_mport *port = NULL;
int rc;
mutex_lock(&rio_mport_list_lock);
list_for_each_entry(port, &rio_mports, node) {
if (port->id == mport_id)
goto found;
}
mutex_unlock(&rio_mport_list_lock);
return -ENODEV;
found:
if (!port->nscan) {
mutex_unlock(&rio_mport_list_lock);
return -EINVAL;
}
if (!try_module_get(port->nscan->owner)) {
mutex_unlock(&rio_mport_list_lock);
return -ENODEV;
}
mutex_unlock(&rio_mport_list_lock);
if (port->host_deviceid >= 0)
rc = port->nscan->enumerate(port, 0);
else
rc = port->nscan->discover(port, RIO_SCAN_ENUM_NO_WAIT);
module_put(port->nscan->owner);
return rc;
}
static void rio_fixup_device(struct rio_dev *dev)
{
}
......@@ -1691,7 +1782,10 @@ static void disc_work_handler(struct work_struct *_work)
work = container_of(_work, struct rio_disc_work, work);
pr_debug("RIO: discovery work for mport %d %s\n",
work->mport->id, work->mport->name);
work->mport->nscan->discover(work->mport, 0);
if (try_module_get(work->mport->nscan->owner)) {
work->mport->nscan->discover(work->mport, 0);
module_put(work->mport->nscan->owner);
}
}
int rio_init_mports(void)
......@@ -1710,8 +1804,10 @@ int rio_init_mports(void)
mutex_lock(&rio_mport_list_lock);
list_for_each_entry(port, &rio_mports, node) {
if (port->host_deviceid >= 0) {
if (port->nscan)
if (port->nscan && try_module_get(port->nscan->owner)) {
port->nscan->enumerate(port, 0);
module_put(port->nscan->owner);
}
} else
n++;
}
......@@ -1725,7 +1821,7 @@ int rio_init_mports(void)
* for each of them. If the code below fails to allocate needed
* resources, exit without error to keep results of enumeration
* process (if any).
* TODO: Implement restart of dicovery process for all or
* TODO: Implement restart of discovery process for all or
* individual discovering mports.
*/
rio_wq = alloc_workqueue("riodisc", 0, 0);
......@@ -1751,9 +1847,9 @@ int rio_init_mports(void)
n++;
}
}
mutex_unlock(&rio_mport_list_lock);
flush_workqueue(rio_wq);
mutex_unlock(&rio_mport_list_lock);
pr_debug("RIO: destroy discovery workqueue\n");
destroy_workqueue(rio_wq);
kfree(work);
......@@ -1784,6 +1880,8 @@ __setup("riohdid=", rio_hdid_setup);
int rio_register_mport(struct rio_mport *port)
{
struct rio_scan_node *scan = NULL;
if (next_portid >= RIO_MAX_MPORTS) {
pr_err("RIO: reached specified max number of mports\n");
return 1;
......@@ -1792,9 +1890,25 @@ int rio_register_mport(struct rio_mport *port)
port->id = next_portid++;
port->host_deviceid = rio_get_hdid(port->id);
port->nscan = NULL;
mutex_lock(&rio_mport_list_lock);
list_add_tail(&port->node, &rio_mports);
/*
* Check if there are any registered enumeration/discovery operations
* that have to be attached to the added mport.
*/
list_for_each_entry(scan, &rio_scans, node) {
if (port->id == scan->mport_id ||
scan->mport_id == RIO_MPORT_ANY) {
port->nscan = scan->ops;
if (port->id == scan->mport_id)
break;
}
}
mutex_unlock(&rio_mport_list_lock);
pr_debug("RIO: %s %s id=%d\n", __func__, port->name, port->id);
return 0;
}
......
......@@ -42,9 +42,10 @@ extern int rio_add_device(struct rio_dev *rdev);
extern int rio_enable_rx_tx_port(struct rio_mport *port, int local, u16 destid,
u8 hopcount, u8 port_num);
extern int rio_register_scan(int mport_id, struct rio_scan *scan_ops);
extern int rio_unregister_scan(int mport_id);
extern int rio_unregister_scan(int mport_id, struct rio_scan *scan_ops);
extern void rio_attach_device(struct rio_dev *rdev);
extern struct rio_mport *rio_find_mport(int mport_id);
extern int rio_mport_scan(int mport_id);
/* Structures internal to the RIO core code */
extern struct device_attribute rio_dev_attrs[];
......
......@@ -465,14 +465,29 @@ static inline struct rio_mport *dma_to_mport(struct dma_device *ddev)
/**
* struct rio_scan - RIO enumeration and discovery operations
* @owner: The module owner of this structure
* @enumerate: Callback to perform RapidIO fabric enumeration.
* @discover: Callback to perform RapidIO fabric discovery.
*/
struct rio_scan {
struct module *owner;
int (*enumerate)(struct rio_mport *mport, u32 flags);
int (*discover)(struct rio_mport *mport, u32 flags);
};
/**
* struct rio_scan_node - list node to register RapidIO enumeration and
* discovery methods with RapidIO core.
* @mport_id: ID of an mport (net) serviced by this enumerator
* @node: node in global list of registered enumerators
* @ops: RIO enumeration and discovery operations
*/
struct rio_scan_node {
int mport_id;
struct list_head node;
struct rio_scan *ops;
};
/* Architecture and hardware-specific functions */
extern int rio_register_mport(struct rio_mport *);
extern int rio_open_inb_mbox(struct rio_mport *, void *, int, int);
......
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