}
}
+/* This is called when we no longer want to hear about Guest changes to a
+ * virtqueue. This is more efficient in high-traffic cases, but it means we
+ * have to set a timer to check if any more changes have occurred. */
static void block_vq(struct virtqueue *vq)
{
struct itimerval itm;
if (!timeout && num)
block_vq(vq);
+ /* We never quite know how long should we wait before we check the
+ * queue again for more packets. We start at 500 microseconds, and if
+ * we get fewer packets than last time, we assume we made the timeout
+ * too small and increase it by 10 microseconds. Otherwise, we drop it
+ * by one microsecond every time. It seems to work well enough. */
if (timeout) {
if (num < last_timeout_num)
timeout_usec += 10;
return features;
}
+/* The virtio core takes the features the Host offers, and copies the
+ * ones supported by the driver into the vdev->features array. Once
+ * that's all sorted out, this routine is called so we can tell the
+ * Host which features we understand and accept. */
static void lg_finalize_features(struct virtio_device *vdev)
{
unsigned int i, bits;
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
+ /* The vdev->feature array is a Linux bitmask: this isn't the
+ * same as a the simple array of bits used by lguest devices
+ * for features. So we do this slow, manual conversion which is
+ * completely general. */
memset(out_features, 0, desc->feature_len);
bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8;
for (i = 0; i < bits; i++) {
vb->vdev->config->get(vb->vdev,
offsetof(struct virtio_balloon_config, num_pages),
&v, sizeof(v));
- return v - vb->num_pages;
+ return (s64)v - vb->num_pages;
}
static void update_balloon_size(struct virtio_balloon *vb)
/* XXX use normal device tree? */
xenbus_suspend();
- err = stop_machine_run(xen_suspend, &cancelled, 0);
+ err = stop_machine(xen_suspend, &cancelled, &cpumask_of_cpu(0));
if (err) {
printk(KERN_ERR "failed to start xen_suspend: %d\n", err);
goto out;
/* "Bogolock": stop the entire machine, disable interrupts. This is a
very heavy lock, which is equivalent to grabbing every spinlock
(and more). So the "read" side to such a lock is anything which
- diables preeempt. */
+ disables preeempt. */
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <asm/system.h>
#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP)
-/* Deprecated, but useful for transition. */
-#define ALL_CPUS ~0U
-
/**
* stop_machine: freeze the machine on all CPUs and run this function
* @fn: the function to run
return ret;
}
#endif /* CONFIG_SMP */
-
-static inline int __deprecated stop_machine_run(int (*fn)(void *), void *data,
- unsigned int cpu)
-{
- /* If they don't care which cpu fn runs on, just pick one. */
- if (cpu == NR_CPUS)
- return stop_machine(fn, data, NULL);
- else if (cpu == ~0U)
- return stop_machine(fn, data, &cpu_possible_map);
- else {
- cpumask_t cpus = cpumask_of_cpu(cpu);
- return stop_machine(fn, data, &cpus);
- }
-}
#endif /* _LINUX_STOP_MACHINE */