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authorRusty Russell <rusty@rustcorp.com.au>2008-05-30 16:09:42 -0400
committerRusty Russell <rusty@rustcorp.com.au>2008-05-30 01:09:42 -0400
commitb769f579081943f14e0ff03b7b0bd3a11cf14625 (patch)
tree026d89b6d937af43af4a692bcf547e032f0c58cc /drivers/virtio/virtio.c
parent5610bd1524332fe7d651eb56cc780e32763a2ac3 (diff)
virtio: set device index in common code.
Anthony Liguori points out that three different transports use the virtio code, but each one keeps its own counter to set the virtio_device's index field. In theory (though not in current practice) this means that names could be duplicated, and that risk grows as more transports are created. So we move the selection of the unique virtio_device.index into the common code in virtio.c, which has the side-benefit of removing duplicate code. The only complexity is that lguest and S/390 use the index to uniquely identify the device in case of catastrophic failure before register_virtio_device() is called: now we use the offset within the descriptor page as a unique identifier for the printks. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chris Lalancette <clalance@redhat.com> Cc: Anthony Liguori <anthony@codemonkey.ws>
Diffstat (limited to 'drivers/virtio/virtio.c')
-rw-r--r--drivers/virtio/virtio.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 59918dfc3cb7..0f3c2bb7bf35 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -2,6 +2,9 @@
2#include <linux/spinlock.h> 2#include <linux/spinlock.h>
3#include <linux/virtio_config.h> 3#include <linux/virtio_config.h>
4 4
5/* Unique numbering for virtio devices. */
6static unsigned int dev_index;
7
5static ssize_t device_show(struct device *_d, 8static ssize_t device_show(struct device *_d,
6 struct device_attribute *attr, char *buf) 9 struct device_attribute *attr, char *buf)
7{ 10{
@@ -166,6 +169,9 @@ int register_virtio_device(struct virtio_device *dev)
166 int err; 169 int err;
167 170
168 dev->dev.bus = &virtio_bus; 171 dev->dev.bus = &virtio_bus;
172
173 /* Assign a unique device index and hence name. */
174 dev->index = dev_index++;
169 sprintf(dev->dev.bus_id, "virtio%u", dev->index); 175 sprintf(dev->dev.bus_id, "virtio%u", dev->index);
170 176
171 /* We always start by resetting the device, in case a previous 177 /* We always start by resetting the device, in case a previous