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linux-next/drivers/virtio/virtio_ring.c
Kees Cook 6da2ec5605 treewide: kmalloc() -> kmalloc_array() 
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

        kmalloc(a * b, gfp)

with:
        kmalloc_array(a * b, gfp)

as well as handling cases of:

        kmalloc(a * b * c, gfp)

with:

        kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kmalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kmalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kmalloc(sizeof(THING) * C2, ...)
|
  kmalloc(sizeof(TYPE) * C2, ...)
|
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00

1253 lines
34 KiB
C
Raw Blame History

/* Virtio ring implementation.
*
* Copyright 2007 Rusty Russell IBM Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/virtio.h>
#include <linux/virtio_ring.h>
#include <linux/virtio_config.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/hrtimer.h>
#include <linux/dma-mapping.h>
#include <xen/xen.h>
#ifdef DEBUG
/* For development, we want to crash whenever the ring is screwed. */
#define BAD_RING(_vq, fmt, args...) \
do { \
dev_err(&(_vq)->vq.vdev->dev, \
"%s:"fmt, (_vq)->vq.name, ##args); \
BUG(); \
} while (0)
/* Caller is supposed to guarantee no reentry. */
#define START_USE(_vq) \
do { \
if ((_vq)->in_use) \
panic("%s:in_use = %i\n", \
(_vq)->vq.name, (_vq)->in_use); \
(_vq)->in_use = __LINE__; \
} while (0)
#define END_USE(_vq) \
do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0)
#else
#define BAD_RING(_vq, fmt, args...) \
do { \
dev_err(&_vq->vq.vdev->dev, \
"%s:"fmt, (_vq)->vq.name, ##args); \
(_vq)->broken = true; \
} while (0)
#define START_USE(vq)
#define END_USE(vq)
#endif
struct vring_desc_state {
void *data; /* Data for callback. */
struct vring_desc *indir_desc; /* Indirect descriptor, if any. */
};
struct vring_virtqueue {
struct virtqueue vq;
/* Actual memory layout for this queue */
struct vring vring;
/* Can we use weak barriers? */
bool weak_barriers;
/* Other side has made a mess, don't try any more. */
bool broken;
/* Host supports indirect buffers */
bool indirect;
/* Host publishes avail event idx */
bool event;
/* Head of free buffer list. */
unsigned int free_head;
/* Number we've added since last sync. */
unsigned int num_added;
/* Last used index we've seen. */
u16 last_used_idx;
/* Last written value to avail->flags */
u16 avail_flags_shadow;
/* Last written value to avail->idx in guest byte order */
u16 avail_idx_shadow;
/* How to notify other side. FIXME: commonalize hcalls! */
bool (*notify)(struct virtqueue *vq);
/* DMA, allocation, and size information */
bool we_own_ring;
size_t queue_size_in_bytes;
dma_addr_t queue_dma_addr;
#ifdef DEBUG
/* They're supposed to lock for us. */
unsigned int in_use;
/* Figure out if their kicks are too delayed. */
bool last_add_time_valid;
ktime_t last_add_time;
#endif
/* Per-descriptor state. */
struct vring_desc_state desc_state[];
};
#define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq)
/*
* Modern virtio devices have feature bits to specify whether they need a
* quirk and bypass the IOMMU. If not there, just use the DMA API.
*
* If there, the interaction between virtio and DMA API is messy.
*
* On most systems with virtio, physical addresses match bus addresses,
* and it doesn't particularly matter whether we use the DMA API.
*
* On some systems, including Xen and any system with a physical device
* that speaks virtio behind a physical IOMMU, we must use the DMA API
* for virtio DMA to work at all.
*
* On other systems, including SPARC and PPC64, virtio-pci devices are
* enumerated as though they are behind an IOMMU, but the virtio host
* ignores the IOMMU, so we must either pretend that the IOMMU isn't
* there or somehow map everything as the identity.
*
* For the time being, we preserve historic behavior and bypass the DMA
* API.
*
* TODO: install a per-device DMA ops structure that does the right thing
* taking into account all the above quirks, and use the DMA API
* unconditionally on data path.
*/
static bool vring_use_dma_api(struct virtio_device *vdev)
{
if (!virtio_has_iommu_quirk(vdev))
return true;
/* Otherwise, we are left to guess. */
/*
* In theory, it's possible to have a buggy QEMU-supposed
* emulated Q35 IOMMU and Xen enabled at the same time. On
* such a configuration, virtio has never worked and will
* not work without an even larger kludge. Instead, enable
* the DMA API if we're a Xen guest, which at least allows
* all of the sensible Xen configurations to work correctly.
*/
if (xen_domain())
return true;
return false;
}
/*
* The DMA ops on various arches are rather gnarly right now, and
* making all of the arch DMA ops work on the vring device itself
* is a mess. For now, we use the parent device for DMA ops.
*/
static inline struct device *vring_dma_dev(const struct vring_virtqueue *vq)
{
return vq->vq.vdev->dev.parent;
}
/* Map one sg entry. */
static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq,
struct scatterlist *sg,
enum dma_data_direction direction)
{
if (!vring_use_dma_api(vq->vq.vdev))
return (dma_addr_t)sg_phys(sg);
/*
* We can't use dma_map_sg, because we don't use scatterlists in
* the way it expects (we don't guarantee that the scatterlist
* will exist for the lifetime of the mapping).
*/
return dma_map_page(vring_dma_dev(vq),
sg_page(sg), sg->offset, sg->length,
direction);
}
static dma_addr_t vring_map_single(const struct vring_virtqueue *vq,
void *cpu_addr, size_t size,
enum dma_data_direction direction)
{
if (!vring_use_dma_api(vq->vq.vdev))
return (dma_addr_t)virt_to_phys(cpu_addr);
return dma_map_single(vring_dma_dev(vq),
cpu_addr, size, direction);
}
static void vring_unmap_one(const struct vring_virtqueue *vq,
struct vring_desc *desc)
{
u16 flags;
if (!vring_use_dma_api(vq->vq.vdev))
return;
flags = virtio16_to_cpu(vq->vq.vdev, desc->flags);
if (flags & VRING_DESC_F_INDIRECT) {
dma_unmap_single(vring_dma_dev(vq),
virtio64_to_cpu(vq->vq.vdev, desc->addr),
virtio32_to_cpu(vq->vq.vdev, desc->len),
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
} else {
dma_unmap_page(vring_dma_dev(vq),
virtio64_to_cpu(vq->vq.vdev, desc->addr),
virtio32_to_cpu(vq->vq.vdev, desc->len),
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
}
static int vring_mapping_error(const struct vring_virtqueue *vq,
dma_addr_t addr)
{
if (!vring_use_dma_api(vq->vq.vdev))
return 0;
return dma_mapping_error(vring_dma_dev(vq), addr);
}
static struct vring_desc *alloc_indirect(struct virtqueue *_vq,
unsigned int total_sg, gfp_t gfp)
{
struct vring_desc *desc;
unsigned int i;
/*
* We require lowmem mappings for the descriptors because
* otherwise virt_to_phys will give us bogus addresses in the
* virtqueue.
*/
gfp &= ~__GFP_HIGHMEM;
desc = kmalloc_array(total_sg, sizeof(struct vring_desc), gfp);
if (!desc)
return NULL;
for (i = 0; i < total_sg; i++)
desc[i].next = cpu_to_virtio16(_vq->vdev, i + 1);
return desc;
}
static inline int virtqueue_add(struct virtqueue *_vq,
struct scatterlist *sgs[],
unsigned int total_sg,
unsigned int out_sgs,
unsigned int in_sgs,
void *data,
void *ctx,
gfp_t gfp)
{
struct vring_virtqueue *vq = to_vvq(_vq);
struct scatterlist *sg;
struct vring_desc *desc;
unsigned int i, n, avail, descs_used, uninitialized_var(prev), err_idx;
int head;
bool indirect;
START_USE(vq);
BUG_ON(data == NULL);
BUG_ON(ctx && vq->indirect);
if (unlikely(vq->broken)) {
END_USE(vq);
return -EIO;
}
#ifdef DEBUG
{
ktime_t now = ktime_get();
/* No kick or get, with .1 second between? Warn. */
if (vq->last_add_time_valid)
WARN_ON(ktime_to_ms(ktime_sub(now, vq->last_add_time))
> 100);
vq->last_add_time = now;
vq->last_add_time_valid = true;
}
#endif
BUG_ON(total_sg == 0);
head = vq->free_head;
/* If the host supports indirect descriptor tables, and we have multiple
* buffers, then go indirect. FIXME: tune this threshold */
if (vq->indirect && total_sg > 1 && vq->vq.num_free)
desc = alloc_indirect(_vq, total_sg, gfp);
else {
desc = NULL;
WARN_ON_ONCE(total_sg > vq->vring.num && !vq->indirect);
}
if (desc) {
/* Use a single buffer which doesn't continue */
indirect = true;
/* Set up rest to use this indirect table. */
i = 0;
descs_used = 1;
} else {
indirect = false;
desc = vq->vring.desc;
i = head;
descs_used = total_sg;
}
if (vq->vq.num_free < descs_used) {
pr_debug("Can't add buf len %i - avail = %i\n",
descs_used, vq->vq.num_free);
/* FIXME: for historical reasons, we force a notify here if
* there are outgoing parts to the buffer. Presumably the
* host should service the ring ASAP. */
if (out_sgs)
vq->notify(&vq->vq);
if (indirect)
kfree(desc);
END_USE(vq);
return -ENOSPC;
}
for (n = 0; n < out_sgs; n++) {
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_TO_DEVICE);
if (vring_mapping_error(vq, addr))
goto unmap_release;
desc[i].flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_NEXT);
desc[i].addr = cpu_to_virtio64(_vq->vdev, addr);
desc[i].len = cpu_to_virtio32(_vq->vdev, sg->length);
prev = i;
i = virtio16_to_cpu(_vq->vdev, desc[i].next);
}
}
for (; n < (out_sgs + in_sgs); n++) {
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_FROM_DEVICE);
if (vring_mapping_error(vq, addr))
goto unmap_release;
desc[i].flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_NEXT | VRING_DESC_F_WRITE);
desc[i].addr = cpu_to_virtio64(_vq->vdev, addr);
desc[i].len = cpu_to_virtio32(_vq->vdev, sg->length);
prev = i;
i = virtio16_to_cpu(_vq->vdev, desc[i].next);
}
}
/* Last one doesn't continue. */
desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT);
if (indirect) {
/* Now that the indirect table is filled in, map it. */
dma_addr_t addr = vring_map_single(
vq, desc, total_sg * sizeof(struct vring_desc),
DMA_TO_DEVICE);
if (vring_mapping_error(vq, addr))
goto unmap_release;
vq->vring.desc[head].flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_INDIRECT);
vq->vring.desc[head].addr = cpu_to_virtio64(_vq->vdev, addr);
vq->vring.desc[head].len = cpu_to_virtio32(_vq->vdev, total_sg * sizeof(struct vring_desc));
}
/* We're using some buffers from the free list. */
vq->vq.num_free -= descs_used;
/* Update free pointer */
if (indirect)
vq->free_head = virtio16_to_cpu(_vq->vdev, vq->vring.desc[head].next);
else
vq->free_head = i;
/* Store token and indirect buffer state. */
vq->desc_state[head].data = data;
if (indirect)
vq->desc_state[head].indir_desc = desc;
else
vq->desc_state[head].indir_desc = ctx;
/* Put entry in available array (but don't update avail->idx until they
* do sync). */
avail = vq->avail_idx_shadow & (vq->vring.num - 1);
vq->vring.avail->ring[avail] = cpu_to_virtio16(_vq->vdev, head);
/* Descriptors and available array need to be set before we expose the
* new available array entries. */
virtio_wmb(vq->weak_barriers);
vq->avail_idx_shadow++;
vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, vq->avail_idx_shadow);
vq->num_added++;
pr_debug("Added buffer head %i to %p\n", head, vq);
END_USE(vq);
/* This is very unlikely, but theoretically possible. Kick
* just in case. */
if (unlikely(vq->num_added == (1 << 16) - 1))
virtqueue_kick(_vq);
return 0;
unmap_release:
err_idx = i;
i = head;
for (n = 0; n < total_sg; n++) {
if (i == err_idx)
break;
vring_unmap_one(vq, &desc[i]);
i = virtio16_to_cpu(_vq->vdev, vq->vring.desc[i].next);
}
if (indirect)
kfree(desc);
END_USE(vq);
return -EIO;
}
/**
* virtqueue_add_sgs - expose buffers to other end
* @vq: the struct virtqueue we're talking about.
* @sgs: array of terminated scatterlists.
* @out_num: the number of scatterlists readable by other side
* @in_num: the number of scatterlists which are writable (after readable ones)
* @data: the token identifying the buffer.
* @gfp: how to do memory allocations (if necessary).
*
* Caller must ensure we don't call this with other virtqueue operations
* at the same time (except where noted).
*
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
*/
int virtqueue_add_sgs(struct virtqueue *_vq,
struct scatterlist *sgs[],
unsigned int out_sgs,
unsigned int in_sgs,
void *data,
gfp_t gfp)
{
unsigned int i, total_sg = 0;
/* Count them first. */
for (i = 0; i < out_sgs + in_sgs; i++) {
struct scatterlist *sg;
for (sg = sgs[i]; sg; sg = sg_next(sg))
total_sg++;
}
return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs,
data, NULL, gfp);
}
EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
/**
* virtqueue_add_outbuf - expose output buffers to other end
* @vq: the struct virtqueue we're talking about.
* @sg: scatterlist (must be well-formed and terminated!)
* @num: the number of entries in @sg readable by other side
* @data: the token identifying the buffer.
* @gfp: how to do memory allocations (if necessary).
*
* Caller must ensure we don't call this with other virtqueue operations
* at the same time (except where noted).
*
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
*/
int virtqueue_add_outbuf(struct virtqueue *vq,
struct scatterlist *sg, unsigned int num,
void *data,
gfp_t gfp)
{
return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp);
}
EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
/**
* virtqueue_add_inbuf - expose input buffers to other end
* @vq: the struct virtqueue we're talking about.
* @sg: scatterlist (must be well-formed and terminated!)
* @num: the number of entries in @sg writable by other side
* @data: the token identifying the buffer.
* @gfp: how to do memory allocations (if necessary).
*
* Caller must ensure we don't call this with other virtqueue operations
* at the same time (except where noted).
*
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
*/
int virtqueue_add_inbuf(struct virtqueue *vq,
struct scatterlist *sg, unsigned int num,
void *data,
gfp_t gfp)
{
return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp);
}
EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
/**
* virtqueue_add_inbuf_ctx - expose input buffers to other end
* @vq: the struct virtqueue we're talking about.
* @sg: scatterlist (must be well-formed and terminated!)
* @num: the number of entries in @sg writable by other side
* @data: the token identifying the buffer.
* @ctx: extra context for the token
* @gfp: how to do memory allocations (if necessary).
*
* Caller must ensure we don't call this with other virtqueue operations
* at the same time (except where noted).
*
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
*/
int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
struct scatterlist *sg, unsigned int num,
void *data,
void *ctx,
gfp_t gfp)
{
return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp);
}
EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
/**
* virtqueue_kick_prepare - first half of split virtqueue_kick call.
* @vq: the struct virtqueue
*
* Instead of virtqueue_kick(), you can do:
* if (virtqueue_kick_prepare(vq))
* virtqueue_notify(vq);
*
* This is sometimes useful because the virtqueue_kick_prepare() needs
* to be serialized, but the actual virtqueue_notify() call does not.
*/
bool virtqueue_kick_prepare(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
u16 new, old;
bool needs_kick;
START_USE(vq);
/* We need to expose available array entries before checking avail
* event. */
virtio_mb(vq->weak_barriers);
old = vq->avail_idx_shadow - vq->num_added;
new = vq->avail_idx_shadow;
vq->num_added = 0;
#ifdef DEBUG
if (vq->last_add_time_valid) {
WARN_ON(ktime_to_ms(ktime_sub(ktime_get(),
vq->last_add_time)) > 100);
}
vq->last_add_time_valid = false;
#endif
if (vq->event) {
needs_kick = vring_need_event(virtio16_to_cpu(_vq->vdev, vring_avail_event(&vq->vring)),
new, old);
} else {
needs_kick = !(vq->vring.used->flags & cpu_to_virtio16(_vq->vdev, VRING_USED_F_NO_NOTIFY));
}
END_USE(vq);
return needs_kick;
}
EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
/**
* virtqueue_notify - second half of split virtqueue_kick call.
* @vq: the struct virtqueue
*
* This does not need to be serialized.
*
* Returns false if host notify failed or queue is broken, otherwise true.
*/
bool virtqueue_notify(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
if (unlikely(vq->broken))
return false;
/* Prod other side to tell it about changes. */
if (!vq->notify(_vq)) {
vq->broken = true;
return false;
}
return true;
}
EXPORT_SYMBOL_GPL(virtqueue_notify);
/**
* virtqueue_kick - update after add_buf
* @vq: the struct virtqueue
*
* After one or more virtqueue_add_* calls, invoke this to kick
* the other side.
*
* Caller must ensure we don't call this with other virtqueue
* operations at the same time (except where noted).
*
* Returns false if kick failed, otherwise true.
*/
bool virtqueue_kick(struct virtqueue *vq)
{
if (virtqueue_kick_prepare(vq))
return virtqueue_notify(vq);
return true;
}
EXPORT_SYMBOL_GPL(virtqueue_kick);
static void detach_buf(struct vring_virtqueue *vq, unsigned int head,
void **ctx)
{
unsigned int i, j;
__virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT);
/* Clear data ptr. */
vq->desc_state[head].data = NULL;
/* Put back on free list: unmap first-level descriptors and find end */
i = head;
while (vq->vring.desc[i].flags & nextflag) {
vring_unmap_one(vq, &vq->vring.desc[i]);
i = virtio16_to_cpu(vq->vq.vdev, vq->vring.desc[i].next);
vq->vq.num_free++;
}
vring_unmap_one(vq, &vq->vring.desc[i]);
vq->vring.desc[i].next = cpu_to_virtio16(vq->vq.vdev, vq->free_head);
vq->free_head = head;
/* Plus final descriptor */
vq->vq.num_free++;
if (vq->indirect) {
struct vring_desc *indir_desc = vq->desc_state[head].indir_desc;
u32 len;
/* Free the indirect table, if any, now that it's unmapped. */
if (!indir_desc)
return;
len = virtio32_to_cpu(vq->vq.vdev, vq->vring.desc[head].len);
BUG_ON(!(vq->vring.desc[head].flags &
cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_INDIRECT)));
BUG_ON(len == 0 || len % sizeof(struct vring_desc));
for (j = 0; j < len / sizeof(struct vring_desc); j++)
vring_unmap_one(vq, &indir_desc[j]);
kfree(indir_desc);
vq->desc_state[head].indir_desc = NULL;
} else if (ctx) {
*ctx = vq->desc_state[head].indir_desc;
}
}
static inline bool more_used(const struct vring_virtqueue *vq)
{
return vq->last_used_idx != virtio16_to_cpu(vq->vq.vdev, vq->vring.used->idx);
}
/**
* virtqueue_get_buf - get the next used buffer
* @vq: the struct virtqueue we're talking about.
* @len: the length written into the buffer
*
* If the device wrote data into the buffer, @len will be set to the
* amount written. This means you don't need to clear the buffer
* beforehand to ensure there's no data leakage in the case of short
* writes.
*
* Caller must ensure we don't call this with other virtqueue
* operations at the same time (except where noted).
*
* Returns NULL if there are no used buffers, or the "data" token
* handed to virtqueue_add_*().
*/
void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
void **ctx)
{
struct vring_virtqueue *vq = to_vvq(_vq);
void *ret;
unsigned int i;
u16 last_used;
START_USE(vq);
if (unlikely(vq->broken)) {
END_USE(vq);
return NULL;
}
if (!more_used(vq)) {
pr_debug("No more buffers in queue\n");
END_USE(vq);
return NULL;
}
/* Only get used array entries after they have been exposed by host. */
virtio_rmb(vq->weak_barriers);
last_used = (vq->last_used_idx & (vq->vring.num - 1));
i = virtio32_to_cpu(_vq->vdev, vq->vring.used->ring[last_used].id);
*len = virtio32_to_cpu(_vq->vdev, vq->vring.used->ring[last_used].len);
if (unlikely(i >= vq->vring.num)) {
BAD_RING(vq, "id %u out of range\n", i);
return NULL;
}
if (unlikely(!vq->desc_state[i].data)) {
BAD_RING(vq, "id %u is not a head!\n", i);
return NULL;
}
/* detach_buf clears data, so grab it now. */
ret = vq->desc_state[i].data;
detach_buf(vq, i, ctx);
vq->last_used_idx++;
/* If we expect an interrupt for the next entry, tell host
* by writing event index and flush out the write before
* the read in the next get_buf call. */
if (!(vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT))
virtio_store_mb(vq->weak_barriers,
&vring_used_event(&vq->vring),
cpu_to_virtio16(_vq->vdev, vq->last_used_idx));
#ifdef DEBUG
vq->last_add_time_valid = false;
#endif
END_USE(vq);
return ret;
}
EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
{
return virtqueue_get_buf_ctx(_vq, len, NULL);
}
EXPORT_SYMBOL_GPL(virtqueue_get_buf);
/**
* virtqueue_disable_cb - disable callbacks
* @vq: the struct virtqueue we're talking about.
*
* Note that this is not necessarily synchronous, hence unreliable and only
* useful as an optimization.
*
* Unlike other operations, this need not be serialized.
*/
void virtqueue_disable_cb(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
if (!(vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) {
vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
if (!vq->event)
vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
}
}
EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
/**
* virtqueue_enable_cb_prepare - restart callbacks after disable_cb
* @vq: the struct virtqueue we're talking about.
*
* This re-enables callbacks; it returns current queue state
* in an opaque unsigned value. This value should be later tested by
* virtqueue_poll, to detect a possible race between the driver checking for
* more work, and enabling callbacks.
*
* Caller must ensure we don't call this with other virtqueue
* operations at the same time (except where noted).
*/
unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
u16 last_used_idx;
START_USE(vq);
/* We optimistically turn back on interrupts, then check if there was
* more to do. */
/* Depending on the VIRTIO_RING_F_EVENT_IDX feature, we need to
* either clear the flags bit or point the event index at the next
* entry. Always do both to keep code simple. */
if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
if (!vq->event)
vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
}
vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, last_used_idx = vq->last_used_idx);
END_USE(vq);
return last_used_idx;
}
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
/**
* virtqueue_poll - query pending used buffers
* @vq: the struct virtqueue we're talking about.
* @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare).
*
* Returns "true" if there are pending used buffers in the queue.
*
* This does not need to be serialized.
*/
bool virtqueue_poll(struct virtqueue *_vq, unsigned last_used_idx)
{
struct vring_virtqueue *vq = to_vvq(_vq);
virtio_mb(vq->weak_barriers);
return (u16)last_used_idx != virtio16_to_cpu(_vq->vdev, vq->vring.used->idx);
}
EXPORT_SYMBOL_GPL(virtqueue_poll);
/**
* virtqueue_enable_cb - restart callbacks after disable_cb.
* @vq: the struct virtqueue we're talking about.
*
* This re-enables callbacks; it returns "false" if there are pending
* buffers in the queue, to detect a possible race between the driver
* checking for more work, and enabling callbacks.
*
* Caller must ensure we don't call this with other virtqueue
* operations at the same time (except where noted).
*/
bool virtqueue_enable_cb(struct virtqueue *_vq)
{
unsigned last_used_idx = virtqueue_enable_cb_prepare(_vq);
return !virtqueue_poll(_vq, last_used_idx);
}
EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
/**
* virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
* @vq: the struct virtqueue we're talking about.
*
* This re-enables callbacks but hints to the other side to delay
* interrupts until most of the available buffers have been processed;
* it returns "false" if there are many pending buffers in the queue,
* to detect a possible race between the driver checking for more work,
* and enabling callbacks.
*
* Caller must ensure we don't call this with other virtqueue
* operations at the same time (except where noted).
*/
bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
u16 bufs;
START_USE(vq);
/* We optimistically turn back on interrupts, then check if there was
* more to do. */
/* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to
* either clear the flags bit or point the event index at the next
* entry. Always update the event index to keep code simple. */
if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
if (!vq->event)
vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
}
/* TODO: tune this threshold */
bufs = (u16)(vq->avail_idx_shadow - vq->last_used_idx) * 3 / 4;
virtio_store_mb(vq->weak_barriers,
&vring_used_event(&vq->vring),
cpu_to_virtio16(_vq->vdev, vq->last_used_idx + bufs));
if (unlikely((u16)(virtio16_to_cpu(_vq->vdev, vq->vring.used->idx) - vq->last_used_idx) > bufs)) {
END_USE(vq);
return false;
}
END_USE(vq);
return true;
}
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
/**
* virtqueue_detach_unused_buf - detach first unused buffer
* @vq: the struct virtqueue we're talking about.
*
* Returns NULL or the "data" token handed to virtqueue_add_*().
* This is not valid on an active queue; it is useful only for device
* shutdown.
*/
void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
unsigned int i;
void *buf;
START_USE(vq);
for (i = 0; i < vq->vring.num; i++) {
if (!vq->desc_state[i].data)
continue;
/* detach_buf clears data, so grab it now. */
buf = vq->desc_state[i].data;
detach_buf(vq, i, NULL);
vq->avail_idx_shadow--;
vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, vq->avail_idx_shadow);
END_USE(vq);
return buf;
}
/* That should have freed everything. */
BUG_ON(vq->vq.num_free != vq->vring.num);
END_USE(vq);
return NULL;
}
EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);
irqreturn_t vring_interrupt(int irq, void *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
if (!more_used(vq)) {
pr_debug("virtqueue interrupt with no work for %p\n", vq);
return IRQ_NONE;
}
if (unlikely(vq->broken))
return IRQ_HANDLED;
pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback);
if (vq->vq.callback)
vq->vq.callback(&vq->vq);
return IRQ_HANDLED;
}
EXPORT_SYMBOL_GPL(vring_interrupt);
struct virtqueue *__vring_new_virtqueue(unsigned int index,
struct vring vring,
struct virtio_device *vdev,
bool weak_barriers,
bool context,
bool (*notify)(struct virtqueue *),
void (*callback)(struct virtqueue *),
const char *name)
{
unsigned int i;
struct vring_virtqueue *vq;
vq = kmalloc(sizeof(*vq) + vring.num * sizeof(struct vring_desc_state),
GFP_KERNEL);
if (!vq)
return NULL;
vq->vring = vring;
vq->vq.callback = callback;
vq->vq.vdev = vdev;
vq->vq.name = name;
vq->vq.num_free = vring.num;
vq->vq.index = index;
vq->we_own_ring = false;
vq->queue_dma_addr = 0;
vq->queue_size_in_bytes = 0;
vq->notify = notify;
vq->weak_barriers = weak_barriers;
vq->broken = false;
vq->last_used_idx = 0;
vq->avail_flags_shadow = 0;
vq->avail_idx_shadow = 0;
vq->num_added = 0;
list_add_tail(&vq->vq.list, &vdev->vqs);
#ifdef DEBUG
vq->in_use = false;
vq->last_add_time_valid = false;
#endif
vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
!context;
vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
/* No callback? Tell other side not to bother us. */
if (!callback) {
vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
if (!vq->event)
vq->vring.avail->flags = cpu_to_virtio16(vdev, vq->avail_flags_shadow);
}
/* Put everything in free lists. */
vq->free_head = 0;
for (i = 0; i < vring.num-1; i++)
vq->vring.desc[i].next = cpu_to_virtio16(vdev, i + 1);
memset(vq->desc_state, 0, vring.num * sizeof(struct vring_desc_state));
return &vq->vq;
}
EXPORT_SYMBOL_GPL(__vring_new_virtqueue);
static void *vring_alloc_queue(struct virtio_device *vdev, size_t size,
dma_addr_t *dma_handle, gfp_t flag)
{
if (vring_use_dma_api(vdev)) {
return dma_alloc_coherent(vdev->dev.parent, size,
dma_handle, flag);
} else {
void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag);
if (queue) {
phys_addr_t phys_addr = virt_to_phys(queue);
*dma_handle = (dma_addr_t)phys_addr;
/*
* Sanity check: make sure we dind't truncate
* the address. The only arches I can find that
* have 64-bit phys_addr_t but 32-bit dma_addr_t
* are certain non-highmem MIPS and x86
* configurations, but these configurations
* should never allocate physical pages above 32
* bits, so this is fine. Just in case, throw a
* warning and abort if we end up with an
* unrepresentable address.
*/
if (WARN_ON_ONCE(*dma_handle != phys_addr)) {
free_pages_exact(queue, PAGE_ALIGN(size));
return NULL;
}
}
return queue;
}
}
static void vring_free_queue(struct virtio_device *vdev, size_t size,
void *queue, dma_addr_t dma_handle)
{
if (vring_use_dma_api(vdev)) {
dma_free_coherent(vdev->dev.parent, size, queue, dma_handle);
} else {
free_pages_exact(queue, PAGE_ALIGN(size));
}
}
struct virtqueue *vring_create_virtqueue(
unsigned int index,
unsigned int num,
unsigned int vring_align,
struct virtio_device *vdev,
bool weak_barriers,
bool may_reduce_num,
bool context,
bool (*notify)(struct virtqueue *),
void (*callback)(struct virtqueue *),
const char *name)
{
struct virtqueue *vq;
void *queue = NULL;
dma_addr_t dma_addr;
size_t queue_size_in_bytes;
struct vring vring;
/* We assume num is a power of 2. */
if (num & (num - 1)) {
dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num);
return NULL;
}
/* TODO: allocate each queue chunk individually */
for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) {
queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
&dma_addr,
GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
if (queue)
break;
}
if (!num)
return NULL;
if (!queue) {
/* Try to get a single page. You are my only hope! */
queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
&dma_addr, GFP_KERNEL|__GFP_ZERO);
}
if (!queue)
return NULL;
queue_size_in_bytes = vring_size(num, vring_align);
vring_init(&vring, num, queue, vring_align);
vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
notify, callback, name);
if (!vq) {
vring_free_queue(vdev, queue_size_in_bytes, queue,
dma_addr);
return NULL;
}
to_vvq(vq)->queue_dma_addr = dma_addr;
to_vvq(vq)->queue_size_in_bytes = queue_size_in_bytes;
to_vvq(vq)->we_own_ring = true;
return vq;
}
EXPORT_SYMBOL_GPL(vring_create_virtqueue);
struct virtqueue *vring_new_virtqueue(unsigned int index,
unsigned int num,
unsigned int vring_align,
struct virtio_device *vdev,
bool weak_barriers,
bool context,
void *pages,
bool (*notify)(struct virtqueue *vq),
void (*callback)(struct virtqueue *vq),
const char *name)
{
struct vring vring;
vring_init(&vring, num, pages, vring_align);
return __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
notify, callback, name);
}
EXPORT_SYMBOL_GPL(vring_new_virtqueue);
void vring_del_virtqueue(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
if (vq->we_own_ring) {
vring_free_queue(vq->vq.vdev, vq->queue_size_in_bytes,
vq->vring.desc, vq->queue_dma_addr);
}
list_del(&_vq->list);
kfree(vq);
}
EXPORT_SYMBOL_GPL(vring_del_virtqueue);
/* Manipulates transport-specific feature bits. */
void vring_transport_features(struct virtio_device *vdev)
{
unsigned int i;
for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) {
switch (i) {
case VIRTIO_RING_F_INDIRECT_DESC:
break;
case VIRTIO_RING_F_EVENT_IDX:
break;
case VIRTIO_F_VERSION_1:
break;
case VIRTIO_F_IOMMU_PLATFORM:
break;
default:
/* We don't understand this bit. */
__virtio_clear_bit(vdev, i);
}
}
}
EXPORT_SYMBOL_GPL(vring_transport_features);
/**
* virtqueue_get_vring_size - return the size of the virtqueue's vring
* @vq: the struct virtqueue containing the vring of interest.
*
* Returns the size of the vring. This is mainly used for boasting to
* userspace. Unlike other operations, this need not be serialized.
*/
unsigned int virtqueue_get_vring_size(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
return vq->vring.num;
}
EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
bool virtqueue_is_broken(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
return vq->broken;
}
EXPORT_SYMBOL_GPL(virtqueue_is_broken);
/*
* This should prevent the device from being used, allowing drivers to
* recover. You may need to grab appropriate locks to flush.
*/
void virtio_break_device(struct virtio_device *dev)
{
struct virtqueue *_vq;
list_for_each_entry(_vq, &dev->vqs, list) {
struct vring_virtqueue *vq = to_vvq(_vq);
vq->broken = true;
}
}
EXPORT_SYMBOL_GPL(virtio_break_device);
dma_addr_t virtqueue_get_desc_addr(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
BUG_ON(!vq->we_own_ring);
return vq->queue_dma_addr;
}
EXPORT_SYMBOL_GPL(virtqueue_get_desc_addr);
dma_addr_t virtqueue_get_avail_addr(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
BUG_ON(!vq->we_own_ring);
return vq->queue_dma_addr +
((char *)vq->vring.avail - (char *)vq->vring.desc);
}
EXPORT_SYMBOL_GPL(virtqueue_get_avail_addr);
dma_addr_t virtqueue_get_used_addr(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
BUG_ON(!vq->we_own_ring);
return vq->queue_dma_addr +
((char *)vq->vring.used - (char *)vq->vring.desc);
}
EXPORT_SYMBOL_GPL(virtqueue_get_used_addr);
const struct vring *virtqueue_get_vring(struct virtqueue *vq)
{
return &to_vvq(vq)->vring;
}
EXPORT_SYMBOL_GPL(virtqueue_get_vring);
MODULE_LICENSE("GPL");
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