virtio: Add block driver support

This adds virtio block device driver support.

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Tuomas Tynkkynen 2018-10-15 02:21:11 -07:00 committed by Simon Glass
parent 4ad54ec4d5
commit f4802209e5
4 changed files with 274 additions and 0 deletions

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@ -36,4 +36,11 @@ config VIRTIO_NET
This is the virtual net driver for virtio. It can be used with
QEMU based targets.
config VIRTIO_BLK
bool "virtio block driver"
depends on VIRTIO
help
This is the virtual block driver for virtio. It can be used with
QEMU based targets.
endmenu

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@ -6,3 +6,4 @@
obj-y += virtio-uclass.o virtio_ring.o
obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o

137
drivers/virtio/virtio_blk.c Normal file
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@ -0,0 +1,137 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
* Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
*/
#include <common.h>
#include <blk.h>
#include <dm.h>
#include <virtio_types.h>
#include <virtio.h>
#include <virtio_ring.h>
#include "virtio_blk.h"
struct virtio_blk_priv {
struct virtqueue *vq;
};
static ulong virtio_blk_do_req(struct udevice *dev, u64 sector,
lbaint_t blkcnt, void *buffer, u32 type)
{
struct virtio_blk_priv *priv = dev_get_priv(dev);
unsigned int num_out = 0, num_in = 0;
struct virtio_sg *sgs[3];
u8 status;
int ret;
struct virtio_blk_outhdr out_hdr = {
.type = cpu_to_virtio32(dev, type),
.sector = cpu_to_virtio64(dev, sector),
};
struct virtio_sg hdr_sg = { &out_hdr, sizeof(out_hdr) };
struct virtio_sg data_sg = { buffer, blkcnt * 512 };
struct virtio_sg status_sg = { &status, sizeof(status) };
sgs[num_out++] = &hdr_sg;
if (type & VIRTIO_BLK_T_OUT)
sgs[num_out++] = &data_sg;
else
sgs[num_out + num_in++] = &data_sg;
sgs[num_out + num_in++] = &status_sg;
ret = virtqueue_add(priv->vq, sgs, num_out, num_in);
if (ret)
return ret;
virtqueue_kick(priv->vq);
while (!virtqueue_get_buf(priv->vq, NULL))
;
return status == VIRTIO_BLK_S_OK ? blkcnt : -EIO;
}
static ulong virtio_blk_read(struct udevice *dev, lbaint_t start,
lbaint_t blkcnt, void *buffer)
{
return virtio_blk_do_req(dev, start, blkcnt, buffer,
VIRTIO_BLK_T_IN);
}
static ulong virtio_blk_write(struct udevice *dev, lbaint_t start,
lbaint_t blkcnt, const void *buffer)
{
return virtio_blk_do_req(dev, start, blkcnt, (void *)buffer,
VIRTIO_BLK_T_OUT);
}
static int virtio_blk_bind(struct udevice *dev)
{
struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
struct blk_desc *desc = dev_get_uclass_platdata(dev);
int devnum;
desc->if_type = IF_TYPE_VIRTIO;
/*
* Initialize the devnum to -ENODEV. This is to make sure that
* blk_next_free_devnum() works as expected, since the default
* value 0 is a valid devnum.
*/
desc->devnum = -ENODEV;
devnum = blk_next_free_devnum(IF_TYPE_VIRTIO);
if (devnum < 0)
return devnum;
desc->devnum = devnum;
desc->part_type = PART_TYPE_UNKNOWN;
/*
* virtio mmio transport supplies string identification for us,
* while pci trnasport uses a 2-byte subvendor value.
*/
if (uc_priv->vendor >> 16)
sprintf(desc->vendor, "%s", (char *)&uc_priv->vendor);
else
sprintf(desc->vendor, "%04x", uc_priv->vendor);
desc->bdev = dev;
/* Indicate what driver features we support */
virtio_driver_features_init(uc_priv, NULL, 0, NULL, 0);
return 0;
}
static int virtio_blk_probe(struct udevice *dev)
{
struct virtio_blk_priv *priv = dev_get_priv(dev);
struct blk_desc *desc = dev_get_uclass_platdata(dev);
u64 cap;
int ret;
ret = virtio_find_vqs(dev, 1, &priv->vq);
if (ret)
return ret;
desc->blksz = 512;
virtio_cread(dev, struct virtio_blk_config, capacity, &cap);
desc->lba = cap;
return 0;
}
static const struct blk_ops virtio_blk_ops = {
.read = virtio_blk_read,
.write = virtio_blk_write,
};
U_BOOT_DRIVER(virtio_blk) = {
.name = VIRTIO_BLK_DRV_NAME,
.id = UCLASS_BLK,
.ops = &virtio_blk_ops,
.bind = virtio_blk_bind,
.probe = virtio_blk_probe,
.remove = virtio_reset,
.priv_auto_alloc_size = sizeof(struct virtio_blk_priv),
.flags = DM_FLAG_ACTIVE_DMA,
};

129
drivers/virtio/virtio_blk.h Normal file
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@ -0,0 +1,129 @@
/* SPDX-License-Identifier: BSD-3-Clause */
/*
* Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
* Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
*
* From Linux kernel include/uapi/linux/virtio_blk.h
*/
#ifndef _LINUX_VIRTIO_BLK_H
#define _LINUX_VIRTIO_BLK_H
/* Feature bits */
#define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */
#define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */
#define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */
#define VIRTIO_BLK_F_RO 5 /* Disk is read-only */
#define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available */
#define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */
#define VIRTIO_BLK_F_MQ 12 /* Support more than one vq */
/* Legacy feature bits */
#ifndef VIRTIO_BLK_NO_LEGACY
#define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */
#define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */
#define VIRTIO_BLK_F_FLUSH 9 /* Flush command supported */
#define VIRTIO_BLK_F_CONFIG_WCE 11 /* Writeback mode available in config */
#ifndef __KERNEL__
/* Old (deprecated) name for VIRTIO_BLK_F_FLUSH */
#define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH
#endif
#endif /* !VIRTIO_BLK_NO_LEGACY */
#define VIRTIO_BLK_ID_BYTES 20 /* ID string length */
struct __packed virtio_blk_config {
/* The capacity (in 512-byte sectors) */
__u64 capacity;
/* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
__u32 size_max;
/* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
__u32 seg_max;
/* geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */
struct virtio_blk_geometry {
__u16 cylinders;
__u8 heads;
__u8 sectors;
} geometry;
/* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
__u32 blk_size;
/* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */
/* exponent for physical block per logical block */
__u8 physical_block_exp;
/* alignment offset in logical blocks */
__u8 alignment_offset;
/* minimum I/O size without performance penalty in logical blocks */
__u16 min_io_size;
/* optimal sustained I/O size in logical blocks */
__u32 opt_io_size;
/* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
__u8 wce;
__u8 unused;
/* number of vqs, only available when VIRTIO_BLK_F_MQ is set */
__u16 num_queues;
};
/*
* Command types
*
* Usage is a bit tricky as some bits are used as flags and some are not.
*
* Rules:
* VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
* VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own
* and may not be combined with any of the other flags.
*/
/* These two define direction */
#define VIRTIO_BLK_T_IN 0
#define VIRTIO_BLK_T_OUT 1
#ifndef VIRTIO_BLK_NO_LEGACY
/* This bit says it's a scsi command, not an actual read or write */
#define VIRTIO_BLK_T_SCSI_CMD 2
#endif /* VIRTIO_BLK_NO_LEGACY */
/* Cache flush command */
#define VIRTIO_BLK_T_FLUSH 4
/* Get device ID command */
#define VIRTIO_BLK_T_GET_ID 8
#ifndef VIRTIO_BLK_NO_LEGACY
/* Barrier before this op */
#define VIRTIO_BLK_T_BARRIER 0x80000000
#endif /* !VIRTIO_BLK_NO_LEGACY */
/*
* This comes first in the read scatter-gather list.
* For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated,
* this is the first element of the read scatter-gather list.
*/
struct virtio_blk_outhdr {
/* VIRTIO_BLK_T* */
__virtio32 type;
/* io priority */
__virtio32 ioprio;
/* Sector (ie. 512 byte offset) */
__virtio64 sector;
};
#ifndef VIRTIO_BLK_NO_LEGACY
struct virtio_scsi_inhdr {
__virtio32 errors;
__virtio32 data_len;
__virtio32 sense_len;
__virtio32 residual;
};
#endif /* !VIRTIO_BLK_NO_LEGACY */
/* And this is the final byte of the write scatter-gather list */
#define VIRTIO_BLK_S_OK 0
#define VIRTIO_BLK_S_IOERR 1
#define VIRTIO_BLK_S_UNSUPP 2
#endif /* _LINUX_VIRTIO_BLK_H */