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/*
* Intel MIC Platform Software Stack (MPSS)
*
* Copyright(c) 2013 Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* The full GNU General Public License is included in this distribution in
* the file called "COPYING".
*
* Disclaimer: The codes contained in these modules may be specific to
* the Intel Software Development Platform codenamed: Knights Ferry, and
* the Intel product codenamed: Knights Corner, and are not backward
* compatible with other Intel products. Additionally, Intel will NOT
* support the codes or instruction set in future products.
*
* Adapted from:
*
* virtio for kvm on s390
*
* Copyright IBM Corp. 2008
*
* 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)
* as published by the Free Software Foundation.
*
* Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
*
* Intel MIC Card driver.
*
*/
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/virtio_config.h>
#include "../common/mic_dev.h"
#include "mic_virtio.h"
#define VIRTIO_SUBCODE_64 0x0D00
#define MIC_MAX_VRINGS 4
struct mic_vdev {
struct virtio_device vdev;
struct mic_device_desc __iomem *desc;
struct mic_device_ctrl __iomem *dc;
struct mic_device *mdev;
void __iomem *vr[MIC_MAX_VRINGS];
int used_size[MIC_MAX_VRINGS];
struct completion reset_done;
struct mic_irq *virtio_cookie;
int c2h_vdev_db;
};
static struct mic_irq *virtio_config_cookie;
#define to_micvdev(vd) container_of(vd, struct mic_vdev, vdev)
/* Helper API to obtain the parent of the virtio device */
static inline struct device *mic_dev(struct mic_vdev *mvdev)
{
return mvdev->vdev.dev.parent;
}
/* This gets the device's feature bits. */
static u64 mic_get_features(struct virtio_device *vdev)
{
unsigned int i, bits;
u32 features = 0;
struct mic_device_desc __iomem *desc = to_micvdev(vdev)->desc;
u8 __iomem *in_features = mic_vq_features(desc);
int feature_len = ioread8(&desc->feature_len);
bits = min_t(unsigned, feature_len, sizeof(features)) * 8;
for (i = 0; i < bits; i++)
if (ioread8(&in_features[i / 8]) & (BIT(i % 8)))
features |= BIT(i);
return features;
}
static int mic_finalize_features(struct virtio_device *vdev)
{
unsigned int i, bits;
struct mic_device_desc __iomem *desc = to_micvdev(vdev)->desc;
u8 feature_len = ioread8(&desc->feature_len);
/* Second half of bitmap is features we accept. */
u8 __iomem *out_features =
mic_vq_features(desc) + feature_len;
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
/* Make sure we don't have any features > 32 bits! */
BUG_ON((u32)vdev->features != vdev->features);
memset_io(out_features, 0, feature_len);
bits = min_t(unsigned, feature_len,
sizeof(vdev->features)) * 8;
for (i = 0; i < bits; i++) {
if (__virtio_test_bit(vdev, i))
iowrite8(ioread8(&out_features[i / 8]) | (1 << (i % 8)),
&out_features[i / 8]);
}
return 0;
}
/*
* Reading and writing elements in config space
*/
static void mic_get(struct virtio_device *vdev, unsigned int offset,
void *buf, unsigned len)
{
struct mic_device_desc __iomem *desc = to_micvdev(vdev)->desc;
if (offset + len > ioread8(&desc->config_len))
return;
memcpy_fromio(buf, mic_vq_configspace(desc) + offset, len);
}
static void mic_set(struct virtio_device *vdev, unsigned int offset,
const void *buf, unsigned len)
{
struct mic_device_desc __iomem *desc = to_micvdev(vdev)->desc;
if (offset + len > ioread8(&desc->config_len))
return;
memcpy_toio(mic_vq_configspace(desc) + offset, buf, len);
}
/*
* The operations to get and set the status word just access the status
* field of the device descriptor. set_status also interrupts the host
* to tell about status changes.
*/
static u8 mic_get_status(struct virtio_device *vdev)
{
return ioread8(&to_micvdev(vdev)->desc->status);
}
static void mic_set_status(struct virtio_device *vdev, u8 status)
{
struct mic_vdev *mvdev = to_micvdev(vdev);
if (!status)
return;
iowrite8(status, &mvdev->desc->status);
mic_send_intr(mvdev->mdev, mvdev->c2h_vdev_db);
}
/* Inform host on a virtio device reset and wait for ack from host */
static void mic_reset_inform_host(struct virtio_device *vdev)
{
struct mic_vdev *mvdev = to_micvdev(vdev);
struct mic_device_ctrl __iomem *dc = mvdev->dc;
int retry;
iowrite8(0, &dc->host_ack);
iowrite8(1, &dc->vdev_reset);
mic_send_intr(mvdev->mdev, mvdev->c2h_vdev_db);
/* Wait till host completes all card accesses and acks the reset */
for (retry = 100; retry--;) {
if (ioread8(&dc->host_ack))
break;
msleep(100);
};
dev_dbg(mic_dev(mvdev), "%s: retry: %d\n", __func__, retry);
/* Reset status to 0 in case we timed out */
iowrite8(0, &mvdev->desc->status);
}
static void mic_reset(struct virtio_device *vdev)
{
struct mic_vdev *mvdev = to_micvdev(vdev);
dev_dbg(mic_dev(mvdev), "%s: virtio id %d\n",
__func__, vdev->id.device);
mic_reset_inform_host(vdev);
complete_all(&mvdev->reset_done);
}
/*
* The virtio_ring code calls this API when it wants to notify the Host.
*/
static bool mic_notify(struct virtqueue *vq)
{
struct mic_vdev *mvdev = vq->priv;
mic_send_intr(mvdev->mdev, mvdev->c2h_vdev_db);
return true;
}
static void mic_del_vq(struct virtqueue *vq, int n)
{
struct mic_vdev *mvdev = to_micvdev(vq->vdev);
struct vring *vr = (struct vring *)(vq + 1);
free_pages((unsigned long) vr->used, get_order(mvdev->used_size[n]));
vring_del_virtqueue(vq);
mic_card_unmap(mvdev->mdev, mvdev->vr[n]);
mvdev->vr[n] = NULL;
}
static void mic_del_vqs(struct virtio_device *vdev)
{
struct mic_vdev *mvdev = to_micvdev(vdev);
struct virtqueue *vq, *n;
int idx = 0;
dev_dbg(mic_dev(mvdev), "%s\n", __func__);
list_for_each_entry_safe(vq, n, &vdev->vqs, list)
mic_del_vq(vq, idx++);
}
/*
* This routine will assign vring's allocated in host/io memory. Code in
* virtio_ring.c however continues to access this io memory as if it were local
* memory without io accessors.
*/
static struct virtqueue *mic_find_vq(struct virtio_device *vdev,
unsigned index,
void (*callback)(struct virtqueue *vq),
const char *name)
{
struct mic_vdev *mvdev = to_micvdev(vdev);
struct mic_vqconfig __iomem *vqconfig;
struct mic_vqconfig config;
struct virtqueue *vq;
void __iomem *va;
struct _mic_vring_info __iomem *info;
void *used;
int vr_size, _vr_size, err, magic;
struct vring *vr;
u8 type = ioread8(&mvdev->desc->type);
if (index >= ioread8(&mvdev->desc->num_vq))
return ERR_PTR(-ENOENT);
if (!name)
return ERR_PTR(-ENOENT);
/* First assign the vring's allocated in host memory */
vqconfig = mic_vq_config(mvdev->desc) + index;
memcpy_fromio(&config, vqconfig, sizeof(config));
_vr_size = vring_size(le16_to_cpu(config.num), MIC_VIRTIO_RING_ALIGN);
vr_size = PAGE_ALIGN(_vr_size + sizeof(struct _mic_vring_info));
va = mic_card_map(mvdev->mdev, le64_to_cpu(config.address), vr_size);
if (!va)
return ERR_PTR(-ENOMEM);
mvdev->vr[index] = va;
memset_io(va, 0x0, _vr_size);
vq = vring_new_virtqueue(index, le16_to_cpu(config.num),
MIC_VIRTIO_RING_ALIGN, vdev, false,
(void __force *)va, mic_notify, callback,
name);
if (!vq) {
err = -ENOMEM;
goto unmap;
}
info = va + _vr_size;
magic = ioread32(&info->magic);
if (WARN(magic != MIC_MAGIC + type + index, "magic mismatch")) {
err = -EIO;
goto unmap;
}
/* Allocate and reassign used ring now */
mvdev->used_size[index] = PAGE_ALIGN(sizeof(__u16) * 3 +
sizeof(struct vring_used_elem) *
le16_to_cpu(config.num));
used = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
get_order(mvdev->used_size[index]));
if (!used) {
err = -ENOMEM;
dev_err(mic_dev(mvdev), "%s %d err %d\n",
__func__, __LINE__, err);
goto del_vq;
}
iowrite64(virt_to_phys(used), &vqconfig->used_address);
/*
* To reassign the used ring here we are directly accessing
* struct vring_virtqueue which is a private data structure
* in virtio_ring.c. At the minimum, a BUILD_BUG_ON() in
* vring_new_virtqueue() would ensure that
* (&vq->vring == (struct vring *) (&vq->vq + 1));
*/
vr = (struct vring *)(vq + 1);
vr->used = used;
vq->priv = mvdev;
return vq;
del_vq:
vring_del_virtqueue(vq);
unmap:
mic_card_unmap(mvdev->mdev, mvdev->vr[index]);
return ERR_PTR(err);
}
static int mic_find_vqs(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[],
vq_callback_t *callbacks[],
const char * const names[])
{
struct mic_vdev *mvdev = to_micvdev(vdev);
struct mic_device_ctrl __iomem *dc = mvdev->dc;
int i, err, retry;
/* We must have this many virtqueues. */
if (nvqs > ioread8(&mvdev->desc->num_vq))
return -ENOENT;
for (i = 0; i < nvqs; ++i) {
dev_dbg(mic_dev(mvdev), "%s: %d: %s\n",
__func__, i, names[i]);
vqs[i] = mic_find_vq(vdev, i, callbacks[i], names[i]);
if (IS_ERR(vqs[i])) {
err = PTR_ERR(vqs[i]);
goto error;
}
}
iowrite8(1, &dc->used_address_updated);
/*
* Send an interrupt to the host to inform it that used
* rings have been re-assigned.
*/
mic_send_intr(mvdev->mdev, mvdev->c2h_vdev_db);
for (retry = 100; retry--;) {
if (!ioread8(&dc->used_address_updated))
break;
msleep(100);
};
dev_dbg(mic_dev(mvdev), "%s: retry: %d\n", __func__, retry);
if (!retry) {
err = -ENODEV;
goto error;
}
return 0;
error:
mic_del_vqs(vdev);
return err;
}
/*
* The config ops structure as defined by virtio config
*/
static struct virtio_config_ops mic_vq_config_ops = {
.get_features = mic_get_features,
.finalize_features = mic_finalize_features,
.get = mic_get,
.set = mic_set,
.get_status = mic_get_status,
.set_status = mic_set_status,
.reset = mic_reset,
.find_vqs = mic_find_vqs,
.del_vqs = mic_del_vqs,
};
static irqreturn_t
mic_virtio_intr_handler(int irq, void *data)
{
struct mic_vdev *mvdev = data;
struct virtqueue *vq;
mic_ack_interrupt(mvdev->mdev);
list_for_each_entry(vq, &mvdev->vdev.vqs, list)
vring_interrupt(0, vq);
return IRQ_HANDLED;
}
static void mic_virtio_release_dev(struct device *_d)
{
/*
* No need for a release method similar to virtio PCI.
* Provide an empty one to avoid getting a warning from core.
*/
}
/*
* adds a new device and register it with virtio
* appropriate drivers are loaded by the device model
*/
static int mic_add_device(struct mic_device_desc __iomem *d,
unsigned int offset, struct mic_driver *mdrv)
{
struct mic_vdev *mvdev;
int ret;
int virtio_db;
u8 type = ioread8(&d->type);
mvdev = kzalloc(sizeof(*mvdev), GFP_KERNEL);
if (!mvdev) {
dev_err(mdrv->dev, "Cannot allocate mic dev %u type %u\n",
offset, type);
return -ENOMEM;
}
mvdev->mdev = &mdrv->mdev;
mvdev->vdev.dev.parent = mdrv->dev;
mvdev->vdev.dev.release = mic_virtio_release_dev;
mvdev->vdev.id.device = type;
mvdev->vdev.config = &mic_vq_config_ops;
mvdev->desc = d;
mvdev->dc = (void __iomem *)d + mic_aligned_desc_size(d);
init_completion(&mvdev->reset_done);
virtio_db = mic_next_card_db();
mvdev->virtio_cookie = mic_request_card_irq(mic_virtio_intr_handler,
NULL, "virtio intr", mvdev, virtio_db);
if (IS_ERR(mvdev->virtio_cookie)) {
ret = PTR_ERR(mvdev->virtio_cookie);
goto kfree;
}
iowrite8((u8)virtio_db, &mvdev->dc->h2c_vdev_db);
mvdev->c2h_vdev_db = ioread8(&mvdev->dc->c2h_vdev_db);
ret = register_virtio_device(&mvdev->vdev);
if (ret) {
dev_err(mic_dev(mvdev),
"Failed to register mic device %u type %u\n",
offset, type);
goto free_irq;
}
iowrite64((u64)mvdev, &mvdev->dc->vdev);
dev_dbg(mic_dev(mvdev), "%s: registered mic device %u type %u mvdev %p\n",
__func__, offset, type, mvdev);
return 0;
free_irq:
mic_free_card_irq(mvdev->virtio_cookie, mvdev);
kfree:
kfree(mvdev);
return ret;
}
/*
* match for a mic device with a specific desc pointer
*/
static int mic_match_desc(struct device *dev, void *data)
{
struct virtio_device *vdev = dev_to_virtio(dev);
struct mic_vdev *mvdev = to_micvdev(vdev);
return mvdev->desc == (void __iomem *)data;
}
static void mic_handle_config_change(struct mic_device_desc __iomem *d,
unsigned int offset, struct mic_driver *mdrv)
{
struct mic_device_ctrl __iomem *dc
= (void __iomem *)d + mic_aligned_desc_size(d);
struct mic_vdev *mvdev = (struct mic_vdev *)ioread64(&dc->vdev);
if (ioread8(&dc->config_change) != MIC_VIRTIO_PARAM_CONFIG_CHANGED)
return;
dev_dbg(mdrv->dev, "%s %d\n", __func__, __LINE__);
virtio_config_changed(&mvdev->vdev);
iowrite8(1, &dc->guest_ack);
}
/*
* removes a virtio device if a hot remove event has been
* requested by the host.
*/
static int mic_remove_device(struct mic_device_desc __iomem *d,
unsigned int offset, struct mic_driver *mdrv)
{
struct mic_device_ctrl __iomem *dc
= (void __iomem *)d + mic_aligned_desc_size(d);
struct mic_vdev *mvdev = (struct mic_vdev *)ioread64(&dc->vdev);
u8 status;
int ret = -1;
if (ioread8(&dc->config_change) == MIC_VIRTIO_PARAM_DEV_REMOVE) {
dev_dbg(mdrv->dev,
"%s %d config_change %d type %d mvdev %p\n",
__func__, __LINE__,
ioread8(&dc->config_change), ioread8(&d->type), mvdev);
status = ioread8(&d->status);
reinit_completion(&mvdev->reset_done);
unregister_virtio_device(&mvdev->vdev);
mic_free_card_irq(mvdev->virtio_cookie, mvdev);
if (status & VIRTIO_CONFIG_S_DRIVER_OK)
wait_for_completion(&mvdev->reset_done);
kfree(mvdev);
iowrite8(1, &dc->guest_ack);
dev_dbg(mdrv->dev, "%s %d guest_ack %d\n",
__func__, __LINE__, ioread8(&dc->guest_ack));
ret = 0;
}
return ret;
}
#define REMOVE_DEVICES true
static void mic_scan_devices(struct mic_driver *mdrv, bool remove)
{
s8 type;
unsigned int i;
struct mic_device_desc __iomem *d;
struct mic_device_ctrl __iomem *dc;
struct device *dev;
int ret;
for (i = sizeof(struct mic_bootparam); i < MIC_DP_SIZE;
i += mic_total_desc_size(d)) {
d = mdrv->dp + i;
dc = (void __iomem *)d + mic_aligned_desc_size(d);
/*
* This read barrier is paired with the corresponding write
* barrier on the host which is inserted before adding or
* removing a virtio device descriptor, by updating the type.
*/
rmb();
type = ioread8(&d->type);
/* end of list */
if (type == 0)
break;
if (type == -1)
continue;
/* device already exists */
dev = device_find_child(mdrv->dev, (void __force *)d,
mic_match_desc);
if (dev) {
if (remove)
iowrite8(MIC_VIRTIO_PARAM_DEV_REMOVE,
&dc->config_change);
put_device(dev);
mic_handle_config_change(d, i, mdrv);
ret = mic_remove_device(d, i, mdrv);
if (!ret && !remove)
iowrite8(-1, &d->type);
if (remove) {
iowrite8(0, &dc->config_change);
iowrite8(0, &dc->guest_ack);
}
continue;
}
/* new device */
dev_dbg(mdrv->dev, "%s %d Adding new virtio device %p\n",
__func__, __LINE__, d);
if (!remove)
mic_add_device(d, i, mdrv);
}
}
/*
* mic_hotplug_device tries to find changes in the device page.
*/
static void mic_hotplug_devices(struct work_struct *work)
{
struct mic_driver *mdrv = container_of(work,
struct mic_driver, hotplug_work);
mic_scan_devices(mdrv, !REMOVE_DEVICES);
}
/*
* Interrupt handler for hot plug/config changes etc.
*/
static irqreturn_t
mic_extint_handler(int irq, void *data)
{
struct mic_driver *mdrv = (struct mic_driver *)data;
dev_dbg(mdrv->dev, "%s %d hotplug work\n",
__func__, __LINE__);
mic_ack_interrupt(&mdrv->mdev);
schedule_work(&mdrv->hotplug_work);
return IRQ_HANDLED;
}
/*
* Init function for virtio
*/
int mic_devices_init(struct mic_driver *mdrv)
{
int rc;
struct mic_bootparam __iomem *bootparam;
int config_db;
INIT_WORK(&mdrv->hotplug_work, mic_hotplug_devices);
mic_scan_devices(mdrv, !REMOVE_DEVICES);
config_db = mic_next_card_db();
virtio_config_cookie = mic_request_card_irq(mic_extint_handler, NULL,
"virtio_config_intr", mdrv,
config_db);
if (IS_ERR(virtio_config_cookie)) {
rc = PTR_ERR(virtio_config_cookie);
goto exit;
}
bootparam = mdrv->dp;
iowrite8(config_db, &bootparam->h2c_config_db);
return 0;
exit:
return rc;
}
/*
* Uninit function for virtio
*/
void mic_devices_uninit(struct mic_driver *mdrv)
{
struct mic_bootparam __iomem *bootparam = mdrv->dp;
iowrite8(-1, &bootparam->h2c_config_db);
mic_free_card_irq(virtio_config_cookie, mdrv);
flush_work(&mdrv->hotplug_work);
mic_scan_devices(mdrv, REMOVE_DEVICES);
}