| Message ID | 1393349085-18122-3-git-send-email-cornelia.huck@de.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 25/02/14 18:24, Cornelia Huck wrote: > Implement the new CCW_CMD_SET_IND_ADAPTER command and try to enable > adapter interrupts for every device on the first startup. If the host > does not support adapter interrupts, fall back to normal I/O interrupts. > > virtio-ccw adapter interrupts use the same isc as normal I/O subchannels > and share a summary indicator for all devices sharing the same indicator > area. > > Indicator bits for the individual virtqueues may be contained in the same > indicator area for different devices. > > Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> This is s390 only code, so I will queue that for my next KVM:s390 pull request (I will also queue patch 1. It is also in s390/features, but patch 2 needs it). For everything else (irqfd etc) I prefer to have some review from the other platforms, since we change common code. Christian > --- > arch/s390/include/asm/irq.h | 1 + > arch/s390/kernel/irq.c | 1 + > drivers/s390/kvm/virtio_ccw.c | 276 +++++++++++++++++++++++++++++++++++++++-- > 3 files changed, 268 insertions(+), 10 deletions(-) > > diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h > index 5f8bcc5..35f0faa 100644 > --- a/arch/s390/include/asm/irq.h > +++ b/arch/s390/include/asm/irq.h > @@ -53,6 +53,7 @@ enum interruption_class { > IRQIO_PCI, > IRQIO_MSI, > IRQIO_VIR, > + IRQIO_VAI, > NMI_NMI, > CPU_RST, > NR_ARCH_IRQS > diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c > index bb27a26..c288ef7 100644 > --- a/arch/s390/kernel/irq.c > +++ b/arch/s390/kernel/irq.c > @@ -84,6 +84,7 @@ static const struct irq_class irqclass_sub_desc[NR_ARCH_IRQS] = { > [IRQIO_PCI] = {.name = "PCI", .desc = "[I/O] PCI Interrupt" }, > [IRQIO_MSI] = {.name = "MSI", .desc = "[I/O] MSI Interrupt" }, > [IRQIO_VIR] = {.name = "VIR", .desc = "[I/O] Virtual I/O Devices"}, > + [IRQIO_VAI] = {.name = "VAI", .desc = "[I/O] Virtual I/O Devices AI"}, > [NMI_NMI] = {.name = "NMI", .desc = "[NMI] Machine Check"}, > [CPU_RST] = {.name = "RST", .desc = "[CPU] CPU Restart"}, > }; > diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c > index 0fc5848..09afefe 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 +60,8 @@ struct virtio_ccw_device { > unsigned long indicators; > unsigned long indicators2; > struct vq_config_block *config_block; > + bool is_thinint; > + void *airq_info; > }; > > struct vq_info_block { > @@ -72,15 +76,38 @@ 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 +118,7 @@ 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 +130,7 @@ 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 +138,125 @@ 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 +293,51 @@ 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 +425,13 @@ 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 +521,52 @@ 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) { > + dev_warn(&vcdev->cdev->dev, > + "enabling adapter interrupts = %d\n", ret); > + if (ret == -EOPNOTSUPP) > + /* > + * The host does not support adapter interrupts > + * for virtio-ccw, stop trying. > + */ > + virtio_ccw_use_airq = 0; > + 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 +596,23 @@ 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; > @@ -663,6 +912,7 @@ 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; > @@ -778,6 +1028,8 @@ 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; > @@ -935,6 +1187,10 @@ 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); > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h index 5f8bcc5..35f0faa 100644 --- a/arch/s390/include/asm/irq.h +++ b/arch/s390/include/asm/irq.h @@ -53,6 +53,7 @@ enum interruption_class { IRQIO_PCI, IRQIO_MSI, IRQIO_VIR, + IRQIO_VAI, NMI_NMI, CPU_RST, NR_ARCH_IRQS diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c index bb27a26..c288ef7 100644 --- a/arch/s390/kernel/irq.c +++ b/arch/s390/kernel/irq.c @@ -84,6 +84,7 @@ static const struct irq_class irqclass_sub_desc[NR_ARCH_IRQS] = { [IRQIO_PCI] = {.name = "PCI", .desc = "[I/O] PCI Interrupt" }, [IRQIO_MSI] = {.name = "MSI", .desc = "[I/O] MSI Interrupt" }, [IRQIO_VIR] = {.name = "VIR", .desc = "[I/O] Virtual I/O Devices"}, + [IRQIO_VAI] = {.name = "VAI", .desc = "[I/O] Virtual I/O Devices AI"}, [NMI_NMI] = {.name = "NMI", .desc = "[NMI] Machine Check"}, [CPU_RST] = {.name = "RST", .desc = "[CPU] CPU Restart"}, }; diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c index 0fc5848..09afefe 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 +60,8 @@ struct virtio_ccw_device { unsigned long indicators; unsigned long indicators2; struct vq_config_block *config_block; + bool is_thinint; + void *airq_info; }; struct vq_info_block { @@ -72,15 +76,38 @@ 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 +118,7 @@ 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 +130,7 @@ 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 +138,125 @@ 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 +293,51 @@ 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 +425,13 @@ 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 +521,52 @@ 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) { + dev_warn(&vcdev->cdev->dev, + "enabling adapter interrupts = %d\n", ret); + if (ret == -EOPNOTSUPP) + /* + * The host does not support adapter interrupts + * for virtio-ccw, stop trying. + */ + virtio_ccw_use_airq = 0; + 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 +596,23 @@ 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; @@ -663,6 +912,7 @@ 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; @@ -778,6 +1028,8 @@ 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; @@ -935,6 +1187,10 @@ 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);
Implement the new CCW_CMD_SET_IND_ADAPTER command and try to enable adapter interrupts for every device on the first startup. If the host does not support adapter interrupts, fall back to normal I/O interrupts. virtio-ccw adapter interrupts use the same isc as normal I/O subchannels and share a summary indicator for all devices sharing the same indicator area. Indicator bits for the individual virtqueues may be contained in the same indicator area for different devices. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> --- arch/s390/include/asm/irq.h | 1 + arch/s390/kernel/irq.c | 1 + drivers/s390/kvm/virtio_ccw.c | 276 +++++++++++++++++++++++++++++++++++++++-- 3 files changed, 268 insertions(+), 10 deletions(-)