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linux/drivers/virtio/virtio_pci_modern_dev.c
Michael S. Tsirkin 3503895788 virtio_pci: move structure to a header 
These are guest/host interfaces, so they belong in the header where e.g.
qemu will know to find them.

Note: we added a new structure as opposed to extending existing one
because someone might be relying on the size of the existing structure
staying unchanged.  Add a warning to avoid using sizeof.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
2023-11-01 09:31:16 -04:00

726 lines
21 KiB
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// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/virtio_pci_modern.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/delay.h>
/*
* vp_modern_map_capability - map a part of virtio pci capability
* @mdev: the modern virtio-pci device
* @off: offset of the capability
* @minlen: minimal length of the capability
* @align: align requirement
* @start: start from the capability
* @size: map size
* @len: the length that is actually mapped
* @pa: physical address of the capability
*
* Returns the io address of for the part of the capability
*/
static void __iomem *
vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off,
size_t minlen, u32 align, u32 start, u32 size,
size_t *len, resource_size_t *pa)
{
struct pci_dev *dev = mdev->pci_dev;
u8 bar;
u32 offset, length;
void __iomem *p;
pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
bar),
&bar);
pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
&offset);
pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
&length);
/* Check if the BAR may have changed since we requested the region. */
if (bar >= PCI_STD_NUM_BARS || !(mdev->modern_bars & (1 << bar))) {
dev_err(&dev->dev,
"virtio_pci: bar unexpectedly changed to %u\n", bar);
return NULL;
}
if (length <= start) {
dev_err(&dev->dev,
"virtio_pci: bad capability len %u (>%u expected)\n",
length, start);
return NULL;
}
if (length - start < minlen) {
dev_err(&dev->dev,
"virtio_pci: bad capability len %u (>=%zu expected)\n",
length, minlen);
return NULL;
}
length -= start;
if (start + offset < offset) {
dev_err(&dev->dev,
"virtio_pci: map wrap-around %u+%u\n",
start, offset);
return NULL;
}
offset += start;
if (offset & (align - 1)) {
dev_err(&dev->dev,
"virtio_pci: offset %u not aligned to %u\n",
offset, align);
return NULL;
}
if (length > size)
length = size;
if (len)
*len = length;
if (minlen + offset < minlen ||
minlen + offset > pci_resource_len(dev, bar)) {
dev_err(&dev->dev,
"virtio_pci: map virtio %zu@%u "
"out of range on bar %i length %lu\n",
minlen, offset,
bar, (unsigned long)pci_resource_len(dev, bar));
return NULL;
}
p = pci_iomap_range(dev, bar, offset, length);
if (!p)
dev_err(&dev->dev,
"virtio_pci: unable to map virtio %u@%u on bar %i\n",
length, offset, bar);
else if (pa)
*pa = pci_resource_start(dev, bar) + offset;
return p;
}
/**
* virtio_pci_find_capability - walk capabilities to find device info.
* @dev: the pci device
* @cfg_type: the VIRTIO_PCI_CAP_* value we seek
* @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
* @bars: the bitmask of BARs
*
* Returns offset of the capability, or 0.
*/
static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
u32 ioresource_types, int *bars)
{
int pos;
for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
pos > 0;
pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
u8 type, bar;
pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
cfg_type),
&type);
pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
bar),
&bar);
/* Ignore structures with reserved BAR values */
if (bar >= PCI_STD_NUM_BARS)
continue;
if (type == cfg_type) {
if (pci_resource_len(dev, bar) &&
pci_resource_flags(dev, bar) & ioresource_types) {
*bars |= (1 << bar);
return pos;
}
}
}
return 0;
}
/* This is part of the ABI. Don't screw with it. */
static inline void check_offsets(void)
{
/* Note: disk space was harmed in compilation of this function. */
BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
offsetof(struct virtio_pci_cap, cap_vndr));
BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
offsetof(struct virtio_pci_cap, cap_next));
BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
offsetof(struct virtio_pci_cap, cap_len));
BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE !=
offsetof(struct virtio_pci_cap, cfg_type));
BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR !=
offsetof(struct virtio_pci_cap, bar));
BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
offsetof(struct virtio_pci_cap, offset));
BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
offsetof(struct virtio_pci_cap, length));
BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
offsetof(struct virtio_pci_notify_cap,
notify_off_multiplier));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
offsetof(struct virtio_pci_common_cfg,
device_feature_select));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
offsetof(struct virtio_pci_common_cfg, device_feature));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
offsetof(struct virtio_pci_common_cfg,
guest_feature_select));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
offsetof(struct virtio_pci_common_cfg, guest_feature));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
offsetof(struct virtio_pci_common_cfg, msix_config));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
offsetof(struct virtio_pci_common_cfg, num_queues));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
offsetof(struct virtio_pci_common_cfg, device_status));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
offsetof(struct virtio_pci_common_cfg, config_generation));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
offsetof(struct virtio_pci_common_cfg, queue_select));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
offsetof(struct virtio_pci_common_cfg, queue_size));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
offsetof(struct virtio_pci_common_cfg, queue_enable));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
offsetof(struct virtio_pci_common_cfg, queue_notify_off));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
offsetof(struct virtio_pci_common_cfg, queue_used_lo));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
offsetof(struct virtio_pci_common_cfg, queue_used_hi));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NDATA !=
offsetof(struct virtio_pci_modern_common_cfg, queue_notify_data));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_RESET !=
offsetof(struct virtio_pci_modern_common_cfg, queue_reset));
}
/*
* vp_modern_probe: probe the modern virtio pci device, note that the
* caller is required to enable PCI device before calling this function.
* @mdev: the modern virtio-pci device
*
* Return 0 on succeed otherwise fail
*/
int vp_modern_probe(struct virtio_pci_modern_device *mdev)
{
struct pci_dev *pci_dev = mdev->pci_dev;
int err, common, isr, notify, device;
u32 notify_length;
u32 notify_offset;
int devid;
check_offsets();
if (mdev->device_id_check) {
devid = mdev->device_id_check(pci_dev);
if (devid < 0)
return devid;
mdev->id.device = devid;
} else {
/* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
return -ENODEV;
if (pci_dev->device < 0x1040) {
/* Transitional devices: use the PCI subsystem device id as
* virtio device id, same as legacy driver always did.
*/
mdev->id.device = pci_dev->subsystem_device;
} else {
/* Modern devices: simply use PCI device id, but start from 0x1040. */
mdev->id.device = pci_dev->device - 0x1040;
}
}
mdev->id.vendor = pci_dev->subsystem_vendor;
/* check for a common config: if not, use legacy mode (bar 0). */
common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
IORESOURCE_IO | IORESOURCE_MEM,
&mdev->modern_bars);
if (!common) {
dev_info(&pci_dev->dev,
"virtio_pci: leaving for legacy driver\n");
return -ENODEV;
}
/* If common is there, these should be too... */
isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
IORESOURCE_IO | IORESOURCE_MEM,
&mdev->modern_bars);
notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
IORESOURCE_IO | IORESOURCE_MEM,
&mdev->modern_bars);
if (!isr || !notify) {
dev_err(&pci_dev->dev,
"virtio_pci: missing capabilities %i/%i/%i\n",
common, isr, notify);
return -EINVAL;
}
err = dma_set_mask_and_coherent(&pci_dev->dev,
mdev->dma_mask ? : DMA_BIT_MASK(64));
if (err)
err = dma_set_mask_and_coherent(&pci_dev->dev,
DMA_BIT_MASK(32));
if (err)
dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
/* Device capability is only mandatory for devices that have
* device-specific configuration.
*/
device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
IORESOURCE_IO | IORESOURCE_MEM,
&mdev->modern_bars);
err = pci_request_selected_regions(pci_dev, mdev->modern_bars,
"virtio-pci-modern");
if (err)
return err;
err = -EINVAL;
mdev->common = vp_modern_map_capability(mdev, common,
sizeof(struct virtio_pci_common_cfg), 4, 0,
offsetofend(struct virtio_pci_modern_common_cfg,
queue_reset),
&mdev->common_len, NULL);
if (!mdev->common)
goto err_map_common;
mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1,
0, 1,
NULL, NULL);
if (!mdev->isr)
goto err_map_isr;
/* Read notify_off_multiplier from config space. */
pci_read_config_dword(pci_dev,
notify + offsetof(struct virtio_pci_notify_cap,
notify_off_multiplier),
&mdev->notify_offset_multiplier);
/* Read notify length and offset from config space. */
pci_read_config_dword(pci_dev,
notify + offsetof(struct virtio_pci_notify_cap,
cap.length),
&notify_length);
pci_read_config_dword(pci_dev,
notify + offsetof(struct virtio_pci_notify_cap,
cap.offset),
&notify_offset);
/* We don't know how many VQs we'll map, ahead of the time.
* If notify length is small, map it all now.
* Otherwise, map each VQ individually later.
*/
if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
mdev->notify_base = vp_modern_map_capability(mdev, notify,
2, 2,
0, notify_length,
&mdev->notify_len,
&mdev->notify_pa);
if (!mdev->notify_base)
goto err_map_notify;
} else {
mdev->notify_map_cap = notify;
}
/* Again, we don't know how much we should map, but PAGE_SIZE
* is more than enough for all existing devices.
*/
if (device) {
mdev->device = vp_modern_map_capability(mdev, device, 0, 4,
0, PAGE_SIZE,
&mdev->device_len,
NULL);
if (!mdev->device)
goto err_map_device;
}
return 0;
err_map_device:
if (mdev->notify_base)
pci_iounmap(pci_dev, mdev->notify_base);
err_map_notify:
pci_iounmap(pci_dev, mdev->isr);
err_map_isr:
pci_iounmap(pci_dev, mdev->common);
err_map_common:
pci_release_selected_regions(pci_dev, mdev->modern_bars);
return err;
}
EXPORT_SYMBOL_GPL(vp_modern_probe);
/*
* vp_modern_remove: remove and cleanup the modern virtio pci device
* @mdev: the modern virtio-pci device
*/
void vp_modern_remove(struct virtio_pci_modern_device *mdev)
{
struct pci_dev *pci_dev = mdev->pci_dev;
if (mdev->device)
pci_iounmap(pci_dev, mdev->device);
if (mdev->notify_base)
pci_iounmap(pci_dev, mdev->notify_base);
pci_iounmap(pci_dev, mdev->isr);
pci_iounmap(pci_dev, mdev->common);
pci_release_selected_regions(pci_dev, mdev->modern_bars);
}
EXPORT_SYMBOL_GPL(vp_modern_remove);
/*
* vp_modern_get_features - get features from device
* @mdev: the modern virtio-pci device
*
* Returns the features read from the device
*/
u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
u64 features;
vp_iowrite32(0, &cfg->device_feature_select);
features = vp_ioread32(&cfg->device_feature);
vp_iowrite32(1, &cfg->device_feature_select);
features |= ((u64)vp_ioread32(&cfg->device_feature) << 32);
return features;
}
EXPORT_SYMBOL_GPL(vp_modern_get_features);
/*
* vp_modern_get_driver_features - get driver features from device
* @mdev: the modern virtio-pci device
*
* Returns the driver features read from the device
*/
u64 vp_modern_get_driver_features(struct virtio_pci_modern_device *mdev)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
u64 features;
vp_iowrite32(0, &cfg->guest_feature_select);
features = vp_ioread32(&cfg->guest_feature);
vp_iowrite32(1, &cfg->guest_feature_select);
features |= ((u64)vp_ioread32(&cfg->guest_feature) << 32);
return features;
}
EXPORT_SYMBOL_GPL(vp_modern_get_driver_features);
/*
* vp_modern_set_features - set features to device
* @mdev: the modern virtio-pci device
* @features: the features set to device
*/
void vp_modern_set_features(struct virtio_pci_modern_device *mdev,
u64 features)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
vp_iowrite32(0, &cfg->guest_feature_select);
vp_iowrite32((u32)features, &cfg->guest_feature);
vp_iowrite32(1, &cfg->guest_feature_select);
vp_iowrite32(features >> 32, &cfg->guest_feature);
}
EXPORT_SYMBOL_GPL(vp_modern_set_features);
/*
* vp_modern_generation - get the device genreation
* @mdev: the modern virtio-pci device
*
* Returns the genreation read from device
*/
u32 vp_modern_generation(struct virtio_pci_modern_device *mdev)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
return vp_ioread8(&cfg->config_generation);
}
EXPORT_SYMBOL_GPL(vp_modern_generation);
/*
* vp_modern_get_status - get the device status
* @mdev: the modern virtio-pci device
*
* Returns the status read from device
*/
u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
return vp_ioread8(&cfg->device_status);
}
EXPORT_SYMBOL_GPL(vp_modern_get_status);
/*
* vp_modern_set_status - set status to device
* @mdev: the modern virtio-pci device
* @status: the status set to device
*/
void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
u8 status)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
/*
* Per memory-barriers.txt, wmb() is not needed to guarantee
* that the cache coherent memory writes have completed
* before writing to the MMIO region.
*/
vp_iowrite8(status, &cfg->device_status);
}
EXPORT_SYMBOL_GPL(vp_modern_set_status);
/*
* vp_modern_get_queue_reset - get the queue reset status
* @mdev: the modern virtio-pci device
* @index: queue index
*/
int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
{
struct virtio_pci_modern_common_cfg __iomem *cfg;
cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
vp_iowrite16(index, &cfg->cfg.queue_select);
return vp_ioread16(&cfg->queue_reset);
}
EXPORT_SYMBOL_GPL(vp_modern_get_queue_reset);
/*
* vp_modern_set_queue_reset - reset the queue
* @mdev: the modern virtio-pci device
* @index: queue index
*/
void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
{
struct virtio_pci_modern_common_cfg __iomem *cfg;
cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
vp_iowrite16(index, &cfg->cfg.queue_select);
vp_iowrite16(1, &cfg->queue_reset);
while (vp_ioread16(&cfg->queue_reset))
msleep(1);
while (vp_ioread16(&cfg->cfg.queue_enable))
msleep(1);
}
EXPORT_SYMBOL_GPL(vp_modern_set_queue_reset);
/*
* vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
* @mdev: the modern virtio-pci device
* @index: queue index
* @vector: the config vector
*
* Returns the config vector read from the device
*/
u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
u16 index, u16 vector)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
vp_iowrite16(index, &cfg->queue_select);
vp_iowrite16(vector, &cfg->queue_msix_vector);
/* Flush the write out to device */
return vp_ioread16(&cfg->queue_msix_vector);
}
EXPORT_SYMBOL_GPL(vp_modern_queue_vector);
/*
* vp_modern_config_vector - set the vector for config interrupt
* @mdev: the modern virtio-pci device
* @vector: the config vector
*
* Returns the config vector read from the device
*/
u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev,
u16 vector)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
/* Setup the vector used for configuration events */
vp_iowrite16(vector, &cfg->msix_config);
/* Verify we had enough resources to assign the vector */
/* Will also flush the write out to device */
return vp_ioread16(&cfg->msix_config);
}
EXPORT_SYMBOL_GPL(vp_modern_config_vector);
/*
* vp_modern_queue_address - set the virtqueue address
* @mdev: the modern virtio-pci device
* @index: the queue index
* @desc_addr: address of the descriptor area
* @driver_addr: address of the driver area
* @device_addr: address of the device area
*/
void vp_modern_queue_address(struct virtio_pci_modern_device *mdev,
u16 index, u64 desc_addr, u64 driver_addr,
u64 device_addr)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
vp_iowrite16(index, &cfg->queue_select);
vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo,
&cfg->queue_desc_hi);
vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo,
&cfg->queue_avail_hi);
vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo,
&cfg->queue_used_hi);
}
EXPORT_SYMBOL_GPL(vp_modern_queue_address);
/*
* vp_modern_set_queue_enable - enable a virtqueue
* @mdev: the modern virtio-pci device
* @index: the queue index
* @enable: whether the virtqueue is enable or not
*/
void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev,
u16 index, bool enable)
{
vp_iowrite16(index, &mdev->common->queue_select);
vp_iowrite16(enable, &mdev->common->queue_enable);
}
EXPORT_SYMBOL_GPL(vp_modern_set_queue_enable);
/*
* vp_modern_get_queue_enable - enable a virtqueue
* @mdev: the modern virtio-pci device
* @index: the queue index
*
* Returns whether a virtqueue is enabled or not
*/
bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev,
u16 index)
{
vp_iowrite16(index, &mdev->common->queue_select);
return vp_ioread16(&mdev->common->queue_enable);
}
EXPORT_SYMBOL_GPL(vp_modern_get_queue_enable);
/*
* vp_modern_set_queue_size - set size for a virtqueue
* @mdev: the modern virtio-pci device
* @index: the queue index
* @size: the size of the virtqueue
*/
void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev,
u16 index, u16 size)
{
vp_iowrite16(index, &mdev->common->queue_select);
vp_iowrite16(size, &mdev->common->queue_size);
}
EXPORT_SYMBOL_GPL(vp_modern_set_queue_size);
/*
* vp_modern_get_queue_size - get size for a virtqueue
* @mdev: the modern virtio-pci device
* @index: the queue index
*
* Returns the size of the virtqueue
*/
u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
u16 index)
{
vp_iowrite16(index, &mdev->common->queue_select);
return vp_ioread16(&mdev->common->queue_size);
}
EXPORT_SYMBOL_GPL(vp_modern_get_queue_size);
/*
* vp_modern_get_num_queues - get the number of virtqueues
* @mdev: the modern virtio-pci device
*
* Returns the number of virtqueues
*/
u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev)
{
return vp_ioread16(&mdev->common->num_queues);
}
EXPORT_SYMBOL_GPL(vp_modern_get_num_queues);
/*
* vp_modern_get_queue_notify_off - get notification offset for a virtqueue
* @mdev: the modern virtio-pci device
* @index: the queue index
*
* Returns the notification offset for a virtqueue
*/
static u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev,
u16 index)
{
vp_iowrite16(index, &mdev->common->queue_select);
return vp_ioread16(&mdev->common->queue_notify_off);
}
/*
* vp_modern_map_vq_notify - map notification area for a
* specific virtqueue
* @mdev: the modern virtio-pci device
* @index: the queue index
* @pa: the pointer to the physical address of the nofity area
*
* Returns the address of the notification area
*/
void __iomem *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
u16 index, resource_size_t *pa)
{
u16 off = vp_modern_get_queue_notify_off(mdev, index);
if (mdev->notify_base) {
/* offset should not wrap */
if ((u64)off * mdev->notify_offset_multiplier + 2
> mdev->notify_len) {
dev_warn(&mdev->pci_dev->dev,
"bad notification offset %u (x %u) "
"for queue %u > %zd",
off, mdev->notify_offset_multiplier,
index, mdev->notify_len);
return NULL;
}
if (pa)
*pa = mdev->notify_pa +
off * mdev->notify_offset_multiplier;
return mdev->notify_base + off * mdev->notify_offset_multiplier;
} else {
return vp_modern_map_capability(mdev,
mdev->notify_map_cap, 2, 2,
off * mdev->notify_offset_multiplier, 2,
NULL, pa);
}
}
EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify);
MODULE_VERSION("0.1");
MODULE_DESCRIPTION("Modern Virtio PCI Device");
MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
MODULE_LICENSE("GPL");
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