Module: xenomai-forge
Branch: next
Commit: e366d3cb7f6a9be29c20aa4c7defea640fa3db41
URL:
http://git.xenomai.org/?p=xenomai-forge.git;a=commit;h=e366d3cb7f6a9be29c20aa4c7defea640fa3db41
Author: Philippe Gerum <r...@xenomai.org>
Date: Mon Aug 11 20:50:37 2014 +0200
rtdm/device: enable minor numbers with named devices
As RTDM named device drivers have no actual entry in any file system,
we lack the device minor information normally available from i-nodes.
Therefore a rtdm_device struct currently represents a device unit in
practice, although it should represent a device type, within a larger
class. This model does not allow for straightforward management of
multiple units of the same device type dynamically in a driver, with a
single rtdm_device description matching all the units available
onboard.
This patch introduces a simple fully dynamic naming convention by
which an application can request to open() a particular device unit,
using the form:
open("device-name@<minor>", ...);
The open() call first attempts to match the full name verbatim, then
checks for any minor specification, only looking for the device name
in a second attempt to retrieve the rtdm_device descriptor.
Upon success, the minor is stored into the rtdm_fd descriptor
representing the new connection, and made available to the driver code
by the rtdm_fd_minor() accessor. When specified, a valid minor value
shall be positive or zero, otherwise the match fails. The default
minor value is -1, which the driver may safely ignore, or choose to
interpret as a special device master/control channel.
e.g.:
open("/dev/foo@0", ..) => connect to unit #0 of device type "foo"
open("/dev/foo@7", ..) => connect to unit #7 of device type "foo"
open("/dev/foo", ..) => connect to control channel of device "foo"
---
include/cobalt/kernel/rtdm/fd.h | 6 ++++++
kernel/cobalt/rtdm/core.c | 7 +++---
kernel/cobalt/rtdm/device.c | 45 +++++++++++++++++++++++++++++++--------
kernel/cobalt/rtdm/internal.h | 4 ++--
kernel/cobalt/rtdm/proc.c | 6 ++++--
5 files changed, 52 insertions(+), 16 deletions(-)
diff --git a/include/cobalt/kernel/rtdm/fd.h b/include/cobalt/kernel/rtdm/fd.h
index 954c60f..d395546 100644
--- a/include/cobalt/kernel/rtdm/fd.h
+++ b/include/cobalt/kernel/rtdm/fd.h
@@ -140,6 +140,7 @@ struct rtdm_fd {
struct rtdm_fd_ops *ops;
struct xnsys_ppd *cont;
unsigned int refs;
+ int minor;
struct list_head cleanup;
};
@@ -155,6 +156,11 @@ static inline struct xnsys_ppd *rtdm_fd_owner(struct
rtdm_fd *fd)
return fd->cont;
}
+static inline int rtdm_fd_minor(struct rtdm_fd *fd)
+{
+ return fd->minor;
+}
+
int rtdm_fd_enter(struct xnsys_ppd *p, struct rtdm_fd *rtdm_fd, int ufd,
unsigned int magic, struct rtdm_fd_ops *ops);
diff --git a/kernel/cobalt/rtdm/core.c b/kernel/cobalt/rtdm/core.c
index 0ebf2b2..0503dfe 100644
--- a/kernel/cobalt/rtdm/core.c
+++ b/kernel/cobalt/rtdm/core.c
@@ -143,9 +143,9 @@ int __rt_dev_open(struct xnsys_ppd *p, int ufd, const char
*path, int oflag)
{
struct rtdm_device *device;
struct rtdm_dev_context *context;
- int ret;
+ int ret, minor;
- device = get_named_device(path);
+ device = __rtdm_get_named_device(path, &minor);
ret = -ENODEV;
if (!device)
goto err_out;
@@ -154,6 +154,7 @@ int __rt_dev_open(struct xnsys_ppd *p, int ufd, const char
*path, int oflag)
if (ret < 0)
goto cleanup_out;
ufd = ret;
+ context->fd.minor = minor;
trace_cobalt_fd_open(current, &context->fd, ufd, oflag);
@@ -184,7 +185,7 @@ int __rt_dev_socket(struct xnsys_ppd *p, int ufd, int
protocol_family,
struct rtdm_dev_context *context;
int ret;
- device = get_protocol_device(protocol_family, socket_type);
+ device = __rtdm_get_protocol_device(protocol_family, socket_type);
ret = -EAFNOSUPPORT;
if (!device)
goto err_out;
diff --git a/kernel/cobalt/rtdm/device.c b/kernel/cobalt/rtdm/device.c
index 547c8f8..a9819cd 100644
--- a/kernel/cobalt/rtdm/device.c
+++ b/kernel/cobalt/rtdm/device.c
@@ -82,25 +82,51 @@ static inline void rtdm_reference_device(struct rtdm_device
*device)
atomic_inc(&device->reserved.refcount);
}
-struct rtdm_device *get_named_device(const char *name)
+struct rtdm_device *__rtdm_get_named_device(const char *name, int *minor_r)
{
struct rtdm_device *device;
+ const char *p = NULL;
+ int ret, minor = -1;
xnhandle_t handle;
- int err;
+ char *base = NULL;
spl_t s;
- err = xnregistry_bind(name, XN_NONBLOCK, XN_RELATIVE, &handle);
- if (err == -EWOULDBLOCK)
- return NULL;
+ /*
+ * First we look for an exact match. If this fails, we look
+ * for a device minor specification. If we find one, we redo
+ * the search only looking for the device base name. The
+ * default minor value is zero.
+ */
+ for (;;) {
+ ret = xnregistry_bind(name, XN_NONBLOCK, XN_RELATIVE, &handle);
+ if (base)
+ kfree(base);
+ if (ret != -EWOULDBLOCK)
+ break;
+ if (p) /* Look for minor only once. */
+ return NULL;
+ p = strrchr(name, '@');
+ if (p == NULL || p[1] == '\0')
+ return NULL;
+ ret = kstrtoint(p + 1, 10, &minor);
+ if (ret || minor < 0)
+ return NULL;
+ base = kstrdup(name, GFP_KERNEL);
+ if (base == NULL)
+ return NULL;
+ base[p - name] = '\0';
+ name = base;
+ }
xnlock_get_irqsave(&rt_dev_lock, s);
device = xnregistry_lookup(handle, NULL);
if (device) {
- if (device->reserved.magic != RTDM_DEVICE_MAGIC)
- device = NULL;
- else
+ if (device->reserved.magic == RTDM_DEVICE_MAGIC) {
rtdm_reference_device(device);
+ *minor_r = minor;
+ } else
+ device = NULL;
}
xnlock_put_irqrestore(&rt_dev_lock, s);
@@ -108,7 +134,8 @@ struct rtdm_device *get_named_device(const char *name)
return device;
}
-struct rtdm_device *get_protocol_device(int protocol_family, int socket_type)
+struct rtdm_device *
+__rtdm_get_protocol_device(int protocol_family, int socket_type)
{
struct rtdm_device *device;
unsigned long long id;
diff --git a/kernel/cobalt/rtdm/internal.h b/kernel/cobalt/rtdm/internal.h
index 47cb862..515f6ba 100644
--- a/kernel/cobalt/rtdm/internal.h
+++ b/kernel/cobalt/rtdm/internal.h
@@ -55,8 +55,8 @@ extern int rtdm_initialised;
void cleanup_process_files(struct rtdm_process *owner);
int rtdm_no_support(void);
-struct rtdm_device *get_named_device(const char *name);
-struct rtdm_device *get_protocol_device(int protocol_family, int socket_type);
+struct rtdm_device *__rtdm_get_named_device(const char *name, int *minor_r);
+struct rtdm_device *__rtdm_get_protocol_device(int protocol_family, int
socket_type);
static inline void rtdm_dereference_device(struct rtdm_device *device)
{
diff --git a/kernel/cobalt/rtdm/proc.c b/kernel/cobalt/rtdm/proc.c
index feb609b..16082fe 100644
--- a/kernel/cobalt/rtdm/proc.c
+++ b/kernel/cobalt/rtdm/proc.c
@@ -187,7 +187,8 @@ static int openfd_show(struct xnvfile_regular_iterator *it,
void *data)
struct rtdm_fd *fd;
if (data == NULL) {
- xnvfile_puts(it, "Index\tLocked\tDevice\t\t\t\tOwner [PID]\n");
+ xnvfile_puts(it, "Index\tLocked\tMinor\tDevice"
+ "\t\t\t\tOwner [PID]\n");
return 0;
}
@@ -202,8 +203,9 @@ static int openfd_show(struct xnvfile_regular_iterator *it,
void *data)
device = context->device;
owner = context->reserved.owner;
- xnvfile_printf(it, "%d\t%d\t%-31s %s [%d]\n", i,
+ xnvfile_printf(it, "%d\t%d\t%d\t%-31s %s [%d]\n", i,
close_lock_count,
+ rtdm_fd_minor(fd),
(device->device_flags & RTDM_NAMED_DEVICE) ?
device->device_name : device->proc_name,
owner ? owner->name : "<kernel>",
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