diff options
Diffstat (limited to 'drivers/s390/kvm/virtio_ccw.c')
| -rw-r--r-- | drivers/s390/kvm/virtio_ccw.c | 323 |
1 files changed, 306 insertions, 17 deletions
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c index 0fc584832001..1e1fc671f89a 100644 --- a/drivers/s390/kvm/virtio_ccw.c +++ b/drivers/s390/kvm/virtio_ccw.c @@ -1,7 +1,7 @@ /* * 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) @@ -32,6 +32,8 @@ #include <asm/cio.h> #include <asm/ccwdev.h> #include <asm/virtio-ccw.h> +#include <asm/isc.h> +#include <asm/airq.h> /* * virtio related functions @@ -58,6 +60,9 @@ struct virtio_ccw_device { unsigned long indicators; unsigned long indicators2; struct vq_config_block *config_block; + bool is_thinint; + bool going_away; + void *airq_info; }; struct vq_info_block { @@ -72,15 +77,38 @@ struct virtio_feature_desc { __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 @@ -91,6 +119,7 @@ struct virtio_ccw_vq_info { #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 @@ -102,6 +131,7 @@ struct virtio_ccw_vq_info { #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) @@ -109,6 +139,125 @@ 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; @@ -145,6 +294,51 @@ static int ccw_io_helper(struct virtio_ccw_device *vcdev, 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) @@ -232,11 +426,13 @@ static void virtio_ccw_del_vqs(struct virtio_device *vdev) { 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); @@ -326,6 +522,54 @@ out_err: 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[], @@ -355,15 +599,23 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs, 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; @@ -636,6 +888,8 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev, struct virtqueue *vq; struct virtio_driver *drv; + if (!vcdev) + return; /* Check if it's a notification from the host. */ if ((intparm == 0) && (scsw_stctl(&irb->scsw) == @@ -663,6 +917,7 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev, 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; @@ -734,23 +989,46 @@ static int virtio_ccw_probe(struct ccw_device *cdev) return 0; } +static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev) +{ + unsigned long flags; + struct virtio_ccw_device *vcdev; + + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); + vcdev = dev_get_drvdata(&cdev->dev); + if (!vcdev || vcdev->going_away) { + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); + return NULL; + } + vcdev->going_away = true; + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); + return vcdev; +} + static void virtio_ccw_remove(struct ccw_device *cdev) { - struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev); + unsigned long flags; + struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev); - if (cdev->online) { + if (vcdev && cdev->online) unregister_virtio_device(&vcdev->vdev); - dev_set_drvdata(&cdev->dev, NULL); - } + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); + dev_set_drvdata(&cdev->dev, NULL); + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); cdev->handler = NULL; } static int virtio_ccw_offline(struct ccw_device *cdev) { - struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev); + unsigned long flags; + struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev); - unregister_virtio_device(&vcdev->vdev); - dev_set_drvdata(&cdev->dev, NULL); + if (vcdev) { + unregister_virtio_device(&vcdev->vdev); + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); + dev_set_drvdata(&cdev->dev, NULL); + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); + } return 0; } @@ -759,6 +1037,7 @@ static int virtio_ccw_online(struct ccw_device *cdev) { int ret; struct virtio_ccw_device *vcdev; + unsigned long flags; vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL); if (!vcdev) { @@ -778,6 +1057,8 @@ static int virtio_ccw_online(struct ccw_device *cdev) 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; @@ -786,7 +1067,9 @@ static int virtio_ccw_online(struct ccw_device *cdev) INIT_LIST_HEAD(&vcdev->virtqueues); spin_lock_init(&vcdev->lock); + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); dev_set_drvdata(&cdev->dev, vcdev); + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); vcdev->vdev.id.vendor = cdev->id.cu_type; vcdev->vdev.id.device = cdev->id.cu_model; ret = register_virtio_device(&vcdev->vdev); @@ -797,7 +1080,9 @@ static int virtio_ccw_online(struct ccw_device *cdev) } return 0; out_put: + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); dev_set_drvdata(&cdev->dev, NULL); + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); put_device(&vcdev->vdev.dev); return ret; out_free: @@ -935,6 +1220,10 @@ module_init(virtio_ccw_init); 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); |