greybus: use ida for cport id allocation
The ida mechanism for allocating ids may be overkill but it works.
Don't preallocate the id 0 for control. That should be done
when initializing connections based on the manifest anyway.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
diff --git a/drivers/staging/greybus/connection.c b/drivers/staging/greybus/connection.c
index 806eb8c..c50472d 100644
--- a/drivers/staging/greybus/connection.c
+++ b/drivers/staging/greybus/connection.c
@@ -14,6 +14,39 @@
static DEFINE_SPINLOCK(gb_connections_lock);
/*
+ * Allocate an available CPort Id for use for the host side of the
+ * given connection. The lowest-available id is returned, so the
+ * first call is guaranteed to allocate CPort Id 0.
+ *
+ * Assigns the connection's hd_cport_id and returns true if successful.
+ * Returns false otherwise.
+ */
+static bool hd_connection_hd_cport_id_alloc(struct gb_connection *connection)
+{
+ struct ida *ida = &connection->hd->cport_id_map;
+ int id;
+
+ id = ida_simple_get(ida, 0, HOST_DEV_CPORT_ID_MAX, GFP_KERNEL);
+ if (id < 0)
+ return false;
+
+ connection->hd_cport_id = (u16)id;
+
+ return true;
+}
+
+/*
+ * Free a previously-allocated CPort Id on the given host device.
+ */
+static void hd_connection_hd_cport_id_free(struct gb_connection *connection)
+{
+ struct ida *ida = &connection->hd->cport_id_map;
+
+ ida_simple_remove(ida, connection->hd_cport_id);
+ connection->hd_cport_id = CPORT_ID_BAD;
+}
+
+/*
* Set up a Greybus connection, representing the bidirectional link
* between a CPort on a (local) Greybus host device and a CPort on
* another Greybus module.
@@ -35,8 +68,9 @@
return NULL;
hd = interface->gmod->hd;
- connection->hd_cport_id = greybus_hd_cport_id_alloc(hd);
- if (connection->hd_cport_id == CPORT_ID_BAD) {
+ connection->hd = hd; /* XXX refcount? */
+ if (!hd_connection_hd_cport_id_alloc(connection)) {
+ /* kref_put(connection->hd); */
kfree(connection);
return NULL;
}
@@ -72,7 +106,7 @@
list_del(&connection->interface_links);
spin_unlock_irq(&gb_connections_lock);
- greybus_hd_cport_id_free(connection->hd, connection->hd_cport_id);
+ hd_connection_hd_cport_id_free(connection);
/* kref_put(connection->interface); */
/* kref_put(connection->hd); */
kfree(connection);
diff --git a/drivers/staging/greybus/core.c b/drivers/staging/greybus/core.c
index 16100e7..40c8996 100644
--- a/drivers/staging/greybus/core.c
+++ b/drivers/staging/greybus/core.c
@@ -282,69 +282,6 @@
static DEFINE_MUTEX(hd_mutex);
-/*
- * Allocate an available CPort Id for use on the given host device.
- * Returns the CPort Id, or CPORT_ID_BAD of none remain.
- *
- * The lowest-available id is returned, so the first call is
- * guaranteed to allocate CPort Id 0.
- */
-u16 greybus_hd_cport_id_alloc(struct greybus_host_device *hd)
-{
- unsigned long cport_id;
-
- /* If none left, return BAD */
- if (hd->cport_id_count == HOST_DEV_CPORT_ID_MAX)
- return CPORT_ID_BAD;
-
- spin_lock_irq(&cport_id_map_lock);
- cport_id = find_next_zero_bit(hd->cport_id_map, HOST_DEV_CPORT_ID_MAX,
- hd->cport_id_next_free);
- if (cport_id < HOST_DEV_CPORT_ID_MAX) {
- hd->cport_id_next_free = cport_id + 1; /* Success */
- hd->cport_id_count++;
- } else {
- /* Lost a race for the last one */
- if (hd->cport_id_count != HOST_DEV_CPORT_ID_MAX) {
- pr_err("bad cport_id_count in alloc");
- hd->cport_id_count = HOST_DEV_CPORT_ID_MAX;
- }
- cport_id = CPORT_ID_BAD;
- }
- spin_unlock_irq(&cport_id_map_lock);
-
- return cport_id;
-}
-
-/*
- * Free a previously-allocated CPort Id on the given host device.
- */
-void greybus_hd_cport_id_free(struct greybus_host_device *hd, u16 cport_id)
-{
- if (cport_id >= HOST_DEV_CPORT_ID_MAX) {
- pr_err("bad cport_id %hu\n", cport_id);
- return;
- }
- if (!hd->cport_id_count) {
- pr_err("too many cport_id frees\n");
- return;
- }
-
- spin_lock_irq(&cport_id_map_lock);
- if (test_and_clear_bit(cport_id, hd->cport_id_map)) {
- if (hd->cport_id_count) {
- hd->cport_id_count--;
- if (cport_id < hd->cport_id_next_free)
- hd->cport_id_next_free = cport_id;
- } else {
- pr_err("bad cport_id_count in free");
- }
- } else {
- pr_err("duplicate cport_id %hu free\n", cport_id);
- }
- spin_unlock_irq(&cport_id_map_lock);
-}
-
static void free_hd(struct kref *kref)
{
struct greybus_host_device *hd;
@@ -368,13 +305,7 @@
hd->driver = driver;
INIT_LIST_HEAD(&hd->modules);
INIT_LIST_HEAD(&hd->connections);
-
- /* Pre-allocate CPort 0 for control stuff. XXX */
- if (greybus_hd_cport_id_alloc(hd) != 0) {
- pr_err("couldn't allocate cport 0\n");
- kfree(hd);
- return NULL;
- }
+ ida_init(&hd->cport_id_map);
return hd;
}
diff --git a/drivers/staging/greybus/greybus.h b/drivers/staging/greybus/greybus.h
index 460ace5..4404d93 100644
--- a/drivers/staging/greybus/greybus.h
+++ b/drivers/staging/greybus/greybus.h
@@ -17,6 +17,7 @@
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/module.h>
+#include <linux/idr.h>
#include "kernel_ver.h"
#include "greybus_id.h"
@@ -194,7 +195,7 @@
struct list_head modules;
struct list_head connections;
- DECLARE_BITMAP(cport_id_map, HOST_DEV_CPORT_ID_MAX);
+ struct ida cport_id_map;
u16 cport_id_count; /* How many have been allocated */
u16 cport_id_next_free; /* Where to start checking anyway */
@@ -202,9 +203,6 @@
unsigned long hd_priv[0] __attribute__ ((aligned(sizeof(s64))));
};
-u16 greybus_hd_cport_id_alloc(struct greybus_host_device *hd);
-void greybus_hd_cport_id_free(struct greybus_host_device *hd, u16 cport_id);
-
struct greybus_host_device *greybus_create_hd(struct greybus_host_driver *host_driver,
struct device *parent);
void greybus_remove_hd(struct greybus_host_device *hd);