virtio-ccw: virtio-ccw adapter interrupt support.
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> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
Cornelia Huck
Christian Borntraeger
Родитель
84ec96a615
Коммит
96b14536d9
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@ -53,6 +53,7 @@ enum interruption_class {
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IRQIO_PCI,
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IRQIO_MSI,
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IRQIO_VIR,
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IRQIO_VAI,
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NMI_NMI,
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CPU_RST,
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NR_ARCH_IRQS
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@ -84,6 +84,7 @@ static const struct irq_class irqclass_sub_desc[NR_ARCH_IRQS] = {
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[IRQIO_PCI] = {.name = "PCI", .desc = "[I/O] PCI Interrupt" },
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[IRQIO_MSI] = {.name = "MSI", .desc = "[I/O] MSI Interrupt" },
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[IRQIO_VIR] = {.name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
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[IRQIO_VAI] = {.name = "VAI", .desc = "[I/O] Virtual I/O Devices AI"},
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[NMI_NMI] = {.name = "NMI", .desc = "[NMI] Machine Check"},
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[CPU_RST] = {.name = "RST", .desc = "[CPU] CPU Restart"},
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};
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@ -1,7 +1,7 @@
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/*
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* ccw based virtio transport
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*
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* Copyright IBM Corp. 2012
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* Copyright IBM Corp. 2012, 2014
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License (version 2 only)
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@ -32,6 +32,8 @@
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#include <asm/cio.h>
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#include <asm/ccwdev.h>
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#include <asm/virtio-ccw.h>
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#include <asm/isc.h>
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#include <asm/airq.h>
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/*
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* virtio related functions
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@ -58,6 +60,8 @@ struct virtio_ccw_device {
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unsigned long indicators;
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unsigned long indicators2;
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struct vq_config_block *config_block;
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bool is_thinint;
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void *airq_info;
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};
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struct vq_info_block {
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@ -72,15 +76,38 @@ struct virtio_feature_desc {
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__u8 index;
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} __packed;
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struct virtio_thinint_area {
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unsigned long summary_indicator;
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unsigned long indicator;
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u64 bit_nr;
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u8 isc;
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} __packed;
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struct virtio_ccw_vq_info {
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struct virtqueue *vq;
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int num;
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void *queue;
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struct vq_info_block *info_block;
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int bit_nr;
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struct list_head node;
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long cookie;
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};
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#define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
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#define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
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#define MAX_AIRQ_AREAS 20
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static int virtio_ccw_use_airq = 1;
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struct airq_info {
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rwlock_t lock;
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u8 summary_indicator;
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struct airq_struct airq;
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struct airq_iv *aiv;
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};
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static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
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#define CCW_CMD_SET_VQ 0x13
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#define CCW_CMD_VDEV_RESET 0x33
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#define CCW_CMD_SET_IND 0x43
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@ -91,6 +118,7 @@ struct virtio_ccw_vq_info {
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#define CCW_CMD_WRITE_CONF 0x21
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#define CCW_CMD_WRITE_STATUS 0x31
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#define CCW_CMD_READ_VQ_CONF 0x32
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#define CCW_CMD_SET_IND_ADAPTER 0x73
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#define VIRTIO_CCW_DOING_SET_VQ 0x00010000
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#define VIRTIO_CCW_DOING_RESET 0x00040000
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@ -102,6 +130,7 @@ struct virtio_ccw_vq_info {
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#define VIRTIO_CCW_DOING_SET_IND 0x01000000
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#define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
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#define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
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#define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
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#define VIRTIO_CCW_INTPARM_MASK 0xffff0000
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static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
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@ -109,6 +138,125 @@ static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
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return container_of(vdev, struct virtio_ccw_device, vdev);
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}
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static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
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{
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unsigned long i, flags;
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write_lock_irqsave(&info->lock, flags);
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for (i = 0; i < airq_iv_end(info->aiv); i++) {
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if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
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airq_iv_free_bit(info->aiv, i);
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airq_iv_set_ptr(info->aiv, i, 0);
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break;
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}
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}
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write_unlock_irqrestore(&info->lock, flags);
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}
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static void virtio_airq_handler(struct airq_struct *airq)
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{
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struct airq_info *info = container_of(airq, struct airq_info, airq);
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unsigned long ai;
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inc_irq_stat(IRQIO_VAI);
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read_lock(&info->lock);
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/* Walk through indicators field, summary indicator active. */
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for (ai = 0;;) {
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ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
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if (ai == -1UL)
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break;
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vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
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}
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info->summary_indicator = 0;
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smp_wmb();
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/* Walk through indicators field, summary indicator not active. */
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for (ai = 0;;) {
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ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
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if (ai == -1UL)
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break;
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vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
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}
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read_unlock(&info->lock);
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}
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static struct airq_info *new_airq_info(void)
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{
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struct airq_info *info;
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int rc;
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info = kzalloc(sizeof(*info), GFP_KERNEL);
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if (!info)
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return NULL;
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rwlock_init(&info->lock);
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info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
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if (!info->aiv) {
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kfree(info);
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return NULL;
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}
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info->airq.handler = virtio_airq_handler;
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info->airq.lsi_ptr = &info->summary_indicator;
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info->airq.lsi_mask = 0xff;
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info->airq.isc = VIRTIO_AIRQ_ISC;
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rc = register_adapter_interrupt(&info->airq);
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if (rc) {
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airq_iv_release(info->aiv);
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kfree(info);
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return NULL;
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}
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return info;
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}
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static void destroy_airq_info(struct airq_info *info)
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{
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if (!info)
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return;
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unregister_adapter_interrupt(&info->airq);
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airq_iv_release(info->aiv);
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kfree(info);
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}
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static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
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u64 *first, void **airq_info)
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{
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int i, j;
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struct airq_info *info;
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unsigned long indicator_addr = 0;
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unsigned long bit, flags;
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for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
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if (!airq_areas[i])
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airq_areas[i] = new_airq_info();
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info = airq_areas[i];
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if (!info)
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return 0;
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write_lock_irqsave(&info->lock, flags);
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bit = airq_iv_alloc(info->aiv, nvqs);
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if (bit == -1UL) {
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/* Not enough vacancies. */
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write_unlock_irqrestore(&info->lock, flags);
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continue;
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}
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*first = bit;
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*airq_info = info;
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indicator_addr = (unsigned long)info->aiv->vector;
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for (j = 0; j < nvqs; j++) {
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airq_iv_set_ptr(info->aiv, bit + j,
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(unsigned long)vqs[j]);
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}
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write_unlock_irqrestore(&info->lock, flags);
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}
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return indicator_addr;
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}
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static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
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{
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struct virtio_ccw_vq_info *info;
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list_for_each_entry(info, &vcdev->virtqueues, node)
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drop_airq_indicator(info->vq, vcdev->airq_info);
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}
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static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
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{
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unsigned long flags;
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@ -145,6 +293,51 @@ static int ccw_io_helper(struct virtio_ccw_device *vcdev,
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return ret ? ret : vcdev->err;
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}
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static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
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struct ccw1 *ccw)
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{
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int ret;
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unsigned long *indicatorp = NULL;
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struct virtio_thinint_area *thinint_area = NULL;
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struct airq_info *airq_info = vcdev->airq_info;
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if (vcdev->is_thinint) {
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thinint_area = kzalloc(sizeof(*thinint_area),
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GFP_DMA | GFP_KERNEL);
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if (!thinint_area)
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return;
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thinint_area->summary_indicator =
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(unsigned long) &airq_info->summary_indicator;
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thinint_area->isc = VIRTIO_AIRQ_ISC;
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ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
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ccw->count = sizeof(*thinint_area);
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ccw->cda = (__u32)(unsigned long) thinint_area;
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} else {
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indicatorp = kmalloc(sizeof(&vcdev->indicators),
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GFP_DMA | GFP_KERNEL);
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if (!indicatorp)
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return;
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*indicatorp = 0;
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ccw->cmd_code = CCW_CMD_SET_IND;
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ccw->count = sizeof(vcdev->indicators);
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ccw->cda = (__u32)(unsigned long) indicatorp;
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}
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/* Deregister indicators from host. */
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vcdev->indicators = 0;
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ccw->flags = 0;
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ret = ccw_io_helper(vcdev, ccw,
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vcdev->is_thinint ?
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VIRTIO_CCW_DOING_SET_IND_ADAPTER :
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VIRTIO_CCW_DOING_SET_IND);
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if (ret && (ret != -ENODEV))
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dev_info(&vcdev->cdev->dev,
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"Failed to deregister indicators (%d)\n", ret);
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else if (vcdev->is_thinint)
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virtio_ccw_drop_indicators(vcdev);
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kfree(indicatorp);
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kfree(thinint_area);
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}
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static inline long do_kvm_notify(struct subchannel_id schid,
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unsigned long queue_index,
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long cookie)
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@ -232,11 +425,13 @@ static void virtio_ccw_del_vqs(struct virtio_device *vdev)
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{
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struct virtqueue *vq, *n;
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struct ccw1 *ccw;
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struct virtio_ccw_device *vcdev = to_vc_device(vdev);
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ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
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if (!ccw)
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return;
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virtio_ccw_drop_indicator(vcdev, ccw);
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list_for_each_entry_safe(vq, n, &vdev->vqs, list)
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virtio_ccw_del_vq(vq, ccw);
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@ -326,6 +521,54 @@ out_err:
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return ERR_PTR(err);
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}
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static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
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struct virtqueue *vqs[], int nvqs,
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struct ccw1 *ccw)
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{
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int ret;
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struct virtio_thinint_area *thinint_area = NULL;
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struct airq_info *info;
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thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
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if (!thinint_area) {
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ret = -ENOMEM;
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goto out;
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}
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/* Try to get an indicator. */
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thinint_area->indicator = get_airq_indicator(vqs, nvqs,
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&thinint_area->bit_nr,
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&vcdev->airq_info);
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if (!thinint_area->indicator) {
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ret = -ENOSPC;
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goto out;
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}
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info = vcdev->airq_info;
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thinint_area->summary_indicator =
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(unsigned long) &info->summary_indicator;
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thinint_area->isc = VIRTIO_AIRQ_ISC;
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ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
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ccw->flags = CCW_FLAG_SLI;
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ccw->count = sizeof(*thinint_area);
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ccw->cda = (__u32)(unsigned long)thinint_area;
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ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
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if (ret) {
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if (ret == -EOPNOTSUPP) {
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/*
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* The host does not support adapter interrupts
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* for virtio-ccw, stop trying.
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*/
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virtio_ccw_use_airq = 0;
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pr_info("Adapter interrupts unsupported on host\n");
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} else
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dev_warn(&vcdev->cdev->dev,
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"enabling adapter interrupts = %d\n", ret);
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virtio_ccw_drop_indicators(vcdev);
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}
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out:
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kfree(thinint_area);
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return ret;
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}
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static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
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struct virtqueue *vqs[],
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vq_callback_t *callbacks[],
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@ -355,15 +598,23 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
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if (!indicatorp)
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goto out;
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*indicatorp = (unsigned long) &vcdev->indicators;
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/* Register queue indicators with host. */
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vcdev->indicators = 0;
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ccw->cmd_code = CCW_CMD_SET_IND;
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ccw->flags = 0;
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ccw->count = sizeof(vcdev->indicators);
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ccw->cda = (__u32)(unsigned long) indicatorp;
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ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
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if (ret)
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goto out;
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if (vcdev->is_thinint) {
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ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
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if (ret)
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/* no error, just fall back to legacy interrupts */
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vcdev->is_thinint = 0;
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}
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if (!vcdev->is_thinint) {
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/* Register queue indicators with host. */
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vcdev->indicators = 0;
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ccw->cmd_code = CCW_CMD_SET_IND;
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ccw->flags = 0;
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ccw->count = sizeof(vcdev->indicators);
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ccw->cda = (__u32)(unsigned long) indicatorp;
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ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
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if (ret)
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goto out;
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}
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/* Register indicators2 with host for config changes */
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*indicatorp = (unsigned long) &vcdev->indicators2;
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vcdev->indicators2 = 0;
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@ -665,6 +916,7 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev,
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case VIRTIO_CCW_DOING_SET_CONF_IND:
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case VIRTIO_CCW_DOING_RESET:
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case VIRTIO_CCW_DOING_READ_VQ_CONF:
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case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
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vcdev->curr_io &= ~activity;
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wake_up(&vcdev->wait_q);
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break;
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@ -795,6 +1047,8 @@ static int virtio_ccw_online(struct ccw_device *cdev)
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goto out_free;
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}
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vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
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vcdev->vdev.dev.parent = &cdev->dev;
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vcdev->vdev.dev.release = virtio_ccw_release_dev;
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vcdev->vdev.config = &virtio_ccw_config_ops;
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@ -956,6 +1210,10 @@ module_init(virtio_ccw_init);
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static void __exit virtio_ccw_exit(void)
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{
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int i;
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ccw_driver_unregister(&virtio_ccw_driver);
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for (i = 0; i < MAX_AIRQ_AREAS; i++)
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destroy_airq_info(airq_areas[i]);
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}
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module_exit(virtio_ccw_exit);
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