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-rw-r--r--Documentation/driver-api/tty/n_gsm.rst4
-rw-r--r--drivers/tty/n_gsm.c192
-rw-r--r--include/uapi/linux/gsmmux.h17
3 files changed, 207 insertions, 6 deletions
diff --git a/Documentation/driver-api/tty/n_gsm.rst b/Documentation/driver-api/tty/n_gsm.rst
index 9447b8a3b8e2..c2624546fb8f 100644
--- a/Documentation/driver-api/tty/n_gsm.rst
+++ b/Documentation/driver-api/tty/n_gsm.rst
@@ -29,6 +29,8 @@ Config Initiator
#. Configure the mux using ``GSMIOC_GETCONF``/``GSMIOC_SETCONF`` ioctl.
+#. Configure DLCs using ``GSMIOC_GETCONF_DLCI``/``GSMIOC_SETCONF_DLCI`` ioctl for non-defaults.
+
#. Obtain base gsmtty number for the used serial port.
Major parts of the initialization program
@@ -120,6 +122,8 @@ Config Requester
#. Configure the mux using ``GSMIOC_GETCONF``/``GSMIOC_SETCONF`` ioctl.
+#. Configure DLCs using ``GSMIOC_GETCONF_DLCI``/``GSMIOC_SETCONF_DLCI`` ioctl for non-defaults.
+
#. Obtain base gsmtty number for the used serial port::
#include <stdio.h>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 7aa05ebed8e1..9d0e7701ffd4 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -128,6 +128,7 @@ struct gsm_msg {
enum gsm_dlci_state {
DLCI_CLOSED,
+ DLCI_WAITING_CONFIG, /* Waiting for DLCI configuration from user */
DLCI_CONFIGURE, /* Sending PN (for adaption > 1) */
DLCI_OPENING, /* Sending SABM not seen UA */
DLCI_OPEN, /* SABM/UA complete */
@@ -330,6 +331,7 @@ struct gsm_mux {
unsigned int t3; /* Power wake-up timer in seconds. */
int n2; /* Retry count */
u8 k; /* Window size */
+ bool wait_config; /* Wait for configuration by ioctl before DLCI open */
u32 keep_alive; /* Control channel keep-alive in 10ms */
/* Statistics (not currently exposed) */
@@ -451,6 +453,7 @@ static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk);
static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len,
u8 ctrl);
static int gsm_send_packet(struct gsm_mux *gsm, struct gsm_msg *msg);
+static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr);
static void gsmld_write_trigger(struct gsm_mux *gsm);
static void gsmld_write_task(struct work_struct *work);
@@ -2280,6 +2283,7 @@ static void gsm_dlci_begin_open(struct gsm_dlci *dlci)
switch (dlci->state) {
case DLCI_CLOSED:
+ case DLCI_WAITING_CONFIG:
case DLCI_CLOSING:
dlci->retries = gsm->n2;
if (!need_pn) {
@@ -2311,6 +2315,7 @@ static void gsm_dlci_set_opening(struct gsm_dlci *dlci)
{
switch (dlci->state) {
case DLCI_CLOSED:
+ case DLCI_WAITING_CONFIG:
case DLCI_CLOSING:
dlci->state = DLCI_OPENING;
break;
@@ -2320,6 +2325,24 @@ static void gsm_dlci_set_opening(struct gsm_dlci *dlci)
}
/**
+ * gsm_dlci_set_wait_config - wait for channel configuration
+ * @dlci: DLCI to configure
+ *
+ * Wait for a DLCI configuration from the application.
+ */
+static void gsm_dlci_set_wait_config(struct gsm_dlci *dlci)
+{
+ switch (dlci->state) {
+ case DLCI_CLOSED:
+ case DLCI_CLOSING:
+ dlci->state = DLCI_WAITING_CONFIG;
+ break;
+ default:
+ break;
+ }
+}
+
+/**
* gsm_dlci_begin_close - start channel open procedure
* @dlci: DLCI to open
*
@@ -2453,6 +2476,128 @@ static void gsm_kick_timer(struct timer_list *t)
pr_info("%s TX queue stalled\n", __func__);
}
+/**
+ * gsm_dlci_copy_config_values - copy DLCI configuration
+ * @dlci: source DLCI
+ * @dc: configuration structure to fill
+ */
+static void gsm_dlci_copy_config_values(struct gsm_dlci *dlci, struct gsm_dlci_config *dc)
+{
+ memset(dc, 0, sizeof(*dc));
+ dc->channel = (u32)dlci->addr;
+ dc->adaption = (u32)dlci->adaption;
+ dc->mtu = (u32)dlci->mtu;
+ dc->priority = (u32)dlci->prio;
+ if (dlci->ftype == UIH)
+ dc->i = 1;
+ else
+ dc->i = 2;
+ dc->k = (u32)dlci->k;
+}
+
+/**
+ * gsm_dlci_config - configure DLCI from configuration
+ * @dlci: DLCI to configure
+ * @dc: DLCI configuration
+ * @open: open DLCI after configuration?
+ */
+static int gsm_dlci_config(struct gsm_dlci *dlci, struct gsm_dlci_config *dc, int open)
+{
+ struct gsm_mux *gsm;
+ bool need_restart = false;
+ bool need_open = false;
+ unsigned int i;
+
+ /*
+ * Check that userspace doesn't put stuff in here to prevent breakages
+ * in the future.
+ */
+ for (i = 0; i < ARRAY_SIZE(dc->reserved); i++)
+ if (dc->reserved[i])
+ return -EINVAL;
+
+ if (!dlci)
+ return -EINVAL;
+ gsm = dlci->gsm;
+
+ /* Stuff we don't support yet - I frame transport */
+ if (dc->adaption != 1 && dc->adaption != 2)
+ return -EOPNOTSUPP;
+ if (dc->mtu > MAX_MTU || dc->mtu < MIN_MTU || dc->mtu > gsm->mru)
+ return -EINVAL;
+ if (dc->priority >= 64)
+ return -EINVAL;
+ if (dc->i == 0 || dc->i > 2) /* UIH and UI only */
+ return -EINVAL;
+ if (dc->k > 7)
+ return -EINVAL;
+
+ /*
+ * See what is needed for reconfiguration
+ */
+ /* Framing fields */
+ if (dc->adaption != dlci->adaption)
+ need_restart = true;
+ if (dc->mtu != dlci->mtu)
+ need_restart = true;
+ if (dc->i != dlci->ftype)
+ need_restart = true;
+ /* Requires care */
+ if (dc->priority != dlci->prio)
+ need_restart = true;
+
+ if ((open && gsm->wait_config) || need_restart)
+ need_open = true;
+ if (dlci->state == DLCI_WAITING_CONFIG) {
+ need_restart = false;
+ need_open = true;
+ }
+
+ /*
+ * Close down what is needed, restart and initiate the new
+ * configuration.
+ */
+ if (need_restart) {
+ gsm_dlci_begin_close(dlci);
+ wait_event_interruptible(gsm->event, dlci->state == DLCI_CLOSED);
+ if (signal_pending(current))
+ return -EINTR;
+ }
+ /*
+ * Setup the new configuration values
+ */
+ dlci->adaption = (int)dc->adaption;
+
+ if (dc->mtu)
+ dlci->mtu = (unsigned int)dc->mtu;
+ else
+ dlci->mtu = gsm->mtu;
+
+ if (dc->priority)
+ dlci->prio = (u8)dc->priority;
+ else
+ dlci->prio = roundup(dlci->addr + 1, 8) - 1;
+
+ if (dc->i == 1)
+ dlci->ftype = UIH;
+ else if (dc->i == 2)
+ dlci->ftype = UI;
+
+ if (dc->k)
+ dlci->k = (u8)dc->k;
+ else
+ dlci->k = gsm->k;
+
+ if (need_open) {
+ if (gsm->initiator)
+ gsm_dlci_begin_open(dlci);
+ else
+ gsm_dlci_set_opening(dlci);
+ }
+
+ return 0;
+}
+
/*
* Allocate/Free DLCI channels
*/
@@ -3078,6 +3223,7 @@ static struct gsm_mux *gsm_alloc_mux(void)
gsm->mru = 64; /* Default to encoding 1 so these should be 64 */
gsm->mtu = 64;
gsm->dead = true; /* Avoid early tty opens */
+ gsm->wait_config = false; /* Disabled */
gsm->keep_alive = 0; /* Disabled */
/* Store the instance to the mux array or abort if no space is
@@ -3218,6 +3364,7 @@ static void gsm_copy_config_ext_values(struct gsm_mux *gsm,
struct gsm_config_ext *ce)
{
memset(ce, 0, sizeof(*ce));
+ ce->wait_config = gsm->wait_config ? 1 : 0;
ce->keep_alive = gsm->keep_alive;
}
@@ -3233,7 +3380,12 @@ static int gsm_config_ext(struct gsm_mux *gsm, struct gsm_config_ext *ce)
if (ce->reserved[i])
return -EINVAL;
+ /*
+ * Setup the new configuration values
+ */
+ gsm->wait_config = ce->wait_config ? true : false;
gsm->keep_alive = ce->keep_alive;
+
return 0;
}
@@ -3436,6 +3588,14 @@ static int gsmld_open(struct tty_struct *tty)
gsm->encoding = GSM_ADV_OPT;
gsmld_attach_gsm(tty, gsm);
+ /* The mux will not be activated yet, we wait for correct
+ * configuration first.
+ */
+ if (gsm->encoding == GSM_BASIC_OPT)
+ gsm->receive = gsm0_receive;
+ else
+ gsm->receive = gsm1_receive;
+
return 0;
}
@@ -4008,7 +4168,6 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp)
{
struct gsm_dlci *dlci = tty->driver_data;
struct tty_port *port = &dlci->port;
- struct gsm_mux *gsm = dlci->gsm;
port->count++;
tty_port_tty_set(port, tty);
@@ -4018,10 +4177,15 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp)
a DM straight back. This is ok as that will have caused a hangup */
tty_port_set_initialized(port, true);
/* Start sending off SABM messages */
- if (gsm->initiator)
- gsm_dlci_begin_open(dlci);
- else
- gsm_dlci_set_opening(dlci);
+ if (!dlci->gsm->wait_config) {
+ /* Start sending off SABM messages */
+ if (dlci->gsm->initiator)
+ gsm_dlci_begin_open(dlci);
+ else
+ gsm_dlci_set_opening(dlci);
+ } else {
+ gsm_dlci_set_wait_config(dlci);
+ }
/* And wait for virtual carrier */
return tty_port_block_til_ready(port, tty, filp);
}
@@ -4142,6 +4306,7 @@ static int gsmtty_ioctl(struct tty_struct *tty,
{
struct gsm_dlci *dlci = tty->driver_data;
struct gsm_netconfig nc;
+ struct gsm_dlci_config dc;
int index;
if (dlci->state == DLCI_CLOSED)
@@ -4165,6 +4330,23 @@ static int gsmtty_ioctl(struct tty_struct *tty,
gsm_destroy_network(dlci);
mutex_unlock(&dlci->mutex);
return 0;
+ case GSMIOC_GETCONF_DLCI:
+ if (copy_from_user(&dc, (void __user *)arg, sizeof(dc)))
+ return -EFAULT;
+ if (dc.channel != dlci->addr)
+ return -EPERM;
+ gsm_dlci_copy_config_values(dlci, &dc);
+ if (copy_to_user((void __user *)arg, &dc, sizeof(dc)))
+ return -EFAULT;
+ return 0;
+ case GSMIOC_SETCONF_DLCI:
+ if (copy_from_user(&dc, (void __user *)arg, sizeof(dc)))
+ return -EFAULT;
+ if (dc.channel >= NUM_DLCI)
+ return -EINVAL;
+ if (dc.channel != 0 && dc.channel != dlci->addr)
+ return -EPERM;
+ return gsm_dlci_config(dlci, &dc, 1);
case TIOCMIWAIT:
return gsm_wait_modem_change(dlci, (u32)arg);
default:
diff --git a/include/uapi/linux/gsmmux.h b/include/uapi/linux/gsmmux.h
index a703780aa095..eb67884e5f38 100644
--- a/include/uapi/linux/gsmmux.h
+++ b/include/uapi/linux/gsmmux.h
@@ -43,10 +43,25 @@ struct gsm_config_ext {
__u32 keep_alive; /* Control channel keep-alive in 1/100th of a
* second (0 to disable)
*/
- __u32 reserved[7]; /* For future use, must be initialized to zero */
+ __u32 wait_config; /* Wait for DLCI config before opening virtual link? */
+ __u32 reserved[6]; /* For future use, must be initialized to zero */
};
#define GSMIOC_GETCONF_EXT _IOR('G', 5, struct gsm_config_ext)
#define GSMIOC_SETCONF_EXT _IOW('G', 6, struct gsm_config_ext)
+/* Set channel accordingly before calling GSMIOC_GETCONF_DLCI. */
+struct gsm_dlci_config {
+ __u32 channel; /* DLCI (0 for the associated DLCI) */
+ __u32 adaption; /* Convergence layer type */
+ __u32 mtu; /* Maximum transfer unit */
+ __u32 priority; /* Priority (0 for default value) */
+ __u32 i; /* Frame type (1 = UIH, 2 = UI) */
+ __u32 k; /* Window size (0 for default value) */
+ __u32 reserved[8]; /* For future use, must be initialized to zero */
+};
+
+#define GSMIOC_GETCONF_DLCI _IOWR('G', 7, struct gsm_dlci_config)
+#define GSMIOC_SETCONF_DLCI _IOW('G', 8, struct gsm_dlci_config)
+
#endif