/*
* ccw based virtio transport
*
- * Copyright IBM Corp. 2012
+ * Copyright IBM Corp. 2012, 2014
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (version 2 only)
#include <asm/cio.h>
#include <asm/ccwdev.h>
#include <asm/virtio-ccw.h>
+#include <asm/isc.h>
+#include <asm/airq.h>
/*
* virtio related functions
unsigned long indicators;
unsigned long indicators2;
struct vq_config_block *config_block;
+ bool is_thinint;
+ void *airq_info;
};
struct vq_info_block {
__u8 index;
} __packed;
+struct virtio_thinint_area {
+ unsigned long summary_indicator;
+ unsigned long indicator;
+ u64 bit_nr;
+ u8 isc;
+} __packed;
+
struct virtio_ccw_vq_info {
struct virtqueue *vq;
int num;
void *queue;
struct vq_info_block *info_block;
+ int bit_nr;
struct list_head node;
long cookie;
};
+#define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
+
+#define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
+#define MAX_AIRQ_AREAS 20
+
+static int virtio_ccw_use_airq = 1;
+
+struct airq_info {
+ rwlock_t lock;
+ u8 summary_indicator;
+ struct airq_struct airq;
+ struct airq_iv *aiv;
+};
+static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
+
#define CCW_CMD_SET_VQ 0x13
#define CCW_CMD_VDEV_RESET 0x33
#define CCW_CMD_SET_IND 0x43
#define CCW_CMD_WRITE_CONF 0x21
#define CCW_CMD_WRITE_STATUS 0x31
#define CCW_CMD_READ_VQ_CONF 0x32
+#define CCW_CMD_SET_IND_ADAPTER 0x73
#define VIRTIO_CCW_DOING_SET_VQ 0x00010000
#define VIRTIO_CCW_DOING_RESET 0x00040000
#define VIRTIO_CCW_DOING_SET_IND 0x01000000
#define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
#define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
+#define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
#define VIRTIO_CCW_INTPARM_MASK 0xffff0000
static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
return container_of(vdev, struct virtio_ccw_device, vdev);
}
+static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
+{
+ unsigned long i, flags;
+
+ write_lock_irqsave(&info->lock, flags);
+ for (i = 0; i < airq_iv_end(info->aiv); i++) {
+ if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
+ airq_iv_free_bit(info->aiv, i);
+ airq_iv_set_ptr(info->aiv, i, 0);
+ break;
+ }
+ }
+ write_unlock_irqrestore(&info->lock, flags);
+}
+
+static void virtio_airq_handler(struct airq_struct *airq)
+{
+ struct airq_info *info = container_of(airq, struct airq_info, airq);
+ unsigned long ai;
+
+ inc_irq_stat(IRQIO_VAI);
+ read_lock(&info->lock);
+ /* Walk through indicators field, summary indicator active. */
+ for (ai = 0;;) {
+ ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
+ if (ai == -1UL)
+ break;
+ vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
+ }
+ info->summary_indicator = 0;
+ smp_wmb();
+ /* Walk through indicators field, summary indicator not active. */
+ for (ai = 0;;) {
+ ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
+ if (ai == -1UL)
+ break;
+ vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
+ }
+ read_unlock(&info->lock);
+}
+
+static struct airq_info *new_airq_info(void)
+{
+ struct airq_info *info;
+ int rc;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return NULL;
+ rwlock_init(&info->lock);
+ info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
+ if (!info->aiv) {
+ kfree(info);
+ return NULL;
+ }
+ info->airq.handler = virtio_airq_handler;
+ info->airq.lsi_ptr = &info->summary_indicator;
+ info->airq.lsi_mask = 0xff;
+ info->airq.isc = VIRTIO_AIRQ_ISC;
+ rc = register_adapter_interrupt(&info->airq);
+ if (rc) {
+ airq_iv_release(info->aiv);
+ kfree(info);
+ return NULL;
+ }
+ return info;
+}
+
+static void destroy_airq_info(struct airq_info *info)
+{
+ if (!info)
+ return;
+
+ unregister_adapter_interrupt(&info->airq);
+ airq_iv_release(info->aiv);
+ kfree(info);
+}
+
+static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
+ u64 *first, void **airq_info)
+{
+ int i, j;
+ struct airq_info *info;
+ unsigned long indicator_addr = 0;
+ unsigned long bit, flags;
+
+ for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
+ if (!airq_areas[i])
+ airq_areas[i] = new_airq_info();
+ info = airq_areas[i];
+ if (!info)
+ return 0;
+ write_lock_irqsave(&info->lock, flags);
+ bit = airq_iv_alloc(info->aiv, nvqs);
+ if (bit == -1UL) {
+ /* Not enough vacancies. */
+ write_unlock_irqrestore(&info->lock, flags);
+ continue;
+ }
+ *first = bit;
+ *airq_info = info;
+ indicator_addr = (unsigned long)info->aiv->vector;
+ for (j = 0; j < nvqs; j++) {
+ airq_iv_set_ptr(info->aiv, bit + j,
+ (unsigned long)vqs[j]);
+ }
+ write_unlock_irqrestore(&info->lock, flags);
+ }
+ return indicator_addr;
+}
+
+static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
+{
+ struct virtio_ccw_vq_info *info;
+
+ list_for_each_entry(info, &vcdev->virtqueues, node)
+ drop_airq_indicator(info->vq, vcdev->airq_info);
+}
+
static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
{
unsigned long flags;
return ret ? ret : vcdev->err;
}
+static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
+ struct ccw1 *ccw)
+{
+ int ret;
+ unsigned long *indicatorp = NULL;
+ struct virtio_thinint_area *thinint_area = NULL;
+ struct airq_info *airq_info = vcdev->airq_info;
+
+ if (vcdev->is_thinint) {
+ thinint_area = kzalloc(sizeof(*thinint_area),
+ GFP_DMA | GFP_KERNEL);
+ if (!thinint_area)
+ return;
+ thinint_area->summary_indicator =
+ (unsigned long) &airq_info->summary_indicator;
+ thinint_area->isc = VIRTIO_AIRQ_ISC;
+ ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
+ ccw->count = sizeof(*thinint_area);
+ ccw->cda = (__u32)(unsigned long) thinint_area;
+ } else {
+ indicatorp = kmalloc(sizeof(&vcdev->indicators),
+ GFP_DMA | GFP_KERNEL);
+ if (!indicatorp)
+ return;
+ *indicatorp = 0;
+ ccw->cmd_code = CCW_CMD_SET_IND;
+ ccw->count = sizeof(vcdev->indicators);
+ ccw->cda = (__u32)(unsigned long) indicatorp;
+ }
+ /* Deregister indicators from host. */
+ vcdev->indicators = 0;
+ ccw->flags = 0;
+ ret = ccw_io_helper(vcdev, ccw,
+ vcdev->is_thinint ?
+ VIRTIO_CCW_DOING_SET_IND_ADAPTER :
+ VIRTIO_CCW_DOING_SET_IND);
+ if (ret && (ret != -ENODEV))
+ dev_info(&vcdev->cdev->dev,
+ "Failed to deregister indicators (%d)\n", ret);
+ else if (vcdev->is_thinint)
+ virtio_ccw_drop_indicators(vcdev);
+ kfree(indicatorp);
+ kfree(thinint_area);
+}
+
static inline long do_kvm_notify(struct subchannel_id schid,
unsigned long queue_index,
long cookie)
{
struct virtqueue *vq, *n;
struct ccw1 *ccw;
+ struct virtio_ccw_device *vcdev = to_vc_device(vdev);
ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
if (!ccw)
return;
+ virtio_ccw_drop_indicator(vcdev, ccw);
list_for_each_entry_safe(vq, n, &vdev->vqs, list)
virtio_ccw_del_vq(vq, ccw);
return ERR_PTR(err);
}
+static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
+ struct virtqueue *vqs[], int nvqs,
+ struct ccw1 *ccw)
+{
+ int ret;
+ struct virtio_thinint_area *thinint_area = NULL;
+ struct airq_info *info;
+
+ thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
+ if (!thinint_area) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ /* Try to get an indicator. */
+ thinint_area->indicator = get_airq_indicator(vqs, nvqs,
+ &thinint_area->bit_nr,
+ &vcdev->airq_info);
+ if (!thinint_area->indicator) {
+ ret = -ENOSPC;
+ goto out;
+ }
+ info = vcdev->airq_info;
+ thinint_area->summary_indicator =
+ (unsigned long) &info->summary_indicator;
+ thinint_area->isc = VIRTIO_AIRQ_ISC;
+ ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
+ ccw->flags = CCW_FLAG_SLI;
+ ccw->count = sizeof(*thinint_area);
+ ccw->cda = (__u32)(unsigned long)thinint_area;
+ ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
+ if (ret) {
+ if (ret == -EOPNOTSUPP) {
+ /*
+ * The host does not support adapter interrupts
+ * for virtio-ccw, stop trying.
+ */
+ virtio_ccw_use_airq = 0;
+ pr_info("Adapter interrupts unsupported on host\n");
+ } else
+ dev_warn(&vcdev->cdev->dev,
+ "enabling adapter interrupts = %d\n", ret);
+ virtio_ccw_drop_indicators(vcdev);
+ }
+out:
+ kfree(thinint_area);
+ return ret;
+}
+
static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[],
vq_callback_t *callbacks[],
if (!indicatorp)
goto out;
*indicatorp = (unsigned long) &vcdev->indicators;
- /* Register queue indicators with host. */
- vcdev->indicators = 0;
- ccw->cmd_code = CCW_CMD_SET_IND;
- ccw->flags = 0;
- ccw->count = sizeof(vcdev->indicators);
- ccw->cda = (__u32)(unsigned long) indicatorp;
- ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
- if (ret)
- goto out;
+ if (vcdev->is_thinint) {
+ ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
+ if (ret)
+ /* no error, just fall back to legacy interrupts */
+ vcdev->is_thinint = 0;
+ }
+ if (!vcdev->is_thinint) {
+ /* Register queue indicators with host. */
+ vcdev->indicators = 0;
+ ccw->cmd_code = CCW_CMD_SET_IND;
+ ccw->flags = 0;
+ ccw->count = sizeof(vcdev->indicators);
+ ccw->cda = (__u32)(unsigned long) indicatorp;
+ ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
+ if (ret)
+ goto out;
+ }
/* Register indicators2 with host for config changes */
*indicatorp = (unsigned long) &vcdev->indicators2;
vcdev->indicators2 = 0;
case VIRTIO_CCW_DOING_SET_CONF_IND:
case VIRTIO_CCW_DOING_RESET:
case VIRTIO_CCW_DOING_READ_VQ_CONF:
+ case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
vcdev->curr_io &= ~activity;
wake_up(&vcdev->wait_q);
break;
goto out_free;
}
+ vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
+
vcdev->vdev.dev.parent = &cdev->dev;
vcdev->vdev.dev.release = virtio_ccw_release_dev;
vcdev->vdev.config = &virtio_ccw_config_ops;
static void __exit virtio_ccw_exit(void)
{
+ int i;
+
ccw_driver_unregister(&virtio_ccw_driver);
+ for (i = 0; i < MAX_AIRQ_AREAS; i++)
+ destroy_airq_info(airq_areas[i]);
}
module_exit(virtio_ccw_exit);
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff