xref: /openbmc/u-boot/drivers/virtio/virtio_blk.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
4  * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
5  */
6 
7 #include <common.h>
8 #include <blk.h>
9 #include <dm.h>
10 #include <virtio_types.h>
11 #include <virtio.h>
12 #include <virtio_ring.h>
13 #include "virtio_blk.h"
14 
15 struct virtio_blk_priv {
16 	struct virtqueue *vq;
17 };
18 
19 static ulong virtio_blk_do_req(struct udevice *dev, u64 sector,
20 			       lbaint_t blkcnt, void *buffer, u32 type)
21 {
22 	struct virtio_blk_priv *priv = dev_get_priv(dev);
23 	unsigned int num_out = 0, num_in = 0;
24 	struct virtio_sg *sgs[3];
25 	u8 status;
26 	int ret;
27 
28 	struct virtio_blk_outhdr out_hdr = {
29 		.type = cpu_to_virtio32(dev, type),
30 		.sector = cpu_to_virtio64(dev, sector),
31 	};
32 	struct virtio_sg hdr_sg = { &out_hdr, sizeof(out_hdr) };
33 	struct virtio_sg data_sg = { buffer, blkcnt * 512 };
34 	struct virtio_sg status_sg = { &status, sizeof(status) };
35 
36 	sgs[num_out++] = &hdr_sg;
37 
38 	if (type & VIRTIO_BLK_T_OUT)
39 		sgs[num_out++] = &data_sg;
40 	else
41 		sgs[num_out + num_in++] = &data_sg;
42 
43 	sgs[num_out + num_in++] = &status_sg;
44 
45 	ret = virtqueue_add(priv->vq, sgs, num_out, num_in);
46 	if (ret)
47 		return ret;
48 
49 	virtqueue_kick(priv->vq);
50 
51 	while (!virtqueue_get_buf(priv->vq, NULL))
52 		;
53 
54 	return status == VIRTIO_BLK_S_OK ? blkcnt : -EIO;
55 }
56 
57 static ulong virtio_blk_read(struct udevice *dev, lbaint_t start,
58 			     lbaint_t blkcnt, void *buffer)
59 {
60 	return virtio_blk_do_req(dev, start, blkcnt, buffer,
61 				 VIRTIO_BLK_T_IN);
62 }
63 
64 static ulong virtio_blk_write(struct udevice *dev, lbaint_t start,
65 			      lbaint_t blkcnt, const void *buffer)
66 {
67 	return virtio_blk_do_req(dev, start, blkcnt, (void *)buffer,
68 				 VIRTIO_BLK_T_OUT);
69 }
70 
71 static int virtio_blk_bind(struct udevice *dev)
72 {
73 	struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
74 	struct blk_desc *desc = dev_get_uclass_platdata(dev);
75 	int devnum;
76 
77 	desc->if_type = IF_TYPE_VIRTIO;
78 	/*
79 	 * Initialize the devnum to -ENODEV. This is to make sure that
80 	 * blk_next_free_devnum() works as expected, since the default
81 	 * value 0 is a valid devnum.
82 	 */
83 	desc->devnum = -ENODEV;
84 	devnum = blk_next_free_devnum(IF_TYPE_VIRTIO);
85 	if (devnum < 0)
86 		return devnum;
87 	desc->devnum = devnum;
88 	desc->part_type = PART_TYPE_UNKNOWN;
89 	/*
90 	 * virtio mmio transport supplies string identification for us,
91 	 * while pci trnasport uses a 2-byte subvendor value.
92 	 */
93 	if (uc_priv->vendor >> 16)
94 		sprintf(desc->vendor, "%s", (char *)&uc_priv->vendor);
95 	else
96 		sprintf(desc->vendor, "%04x", uc_priv->vendor);
97 	desc->bdev = dev;
98 
99 	/* Indicate what driver features we support */
100 	virtio_driver_features_init(uc_priv, NULL, 0, NULL, 0);
101 
102 	return 0;
103 }
104 
105 static int virtio_blk_probe(struct udevice *dev)
106 {
107 	struct virtio_blk_priv *priv = dev_get_priv(dev);
108 	struct blk_desc *desc = dev_get_uclass_platdata(dev);
109 	u64 cap;
110 	int ret;
111 
112 	ret = virtio_find_vqs(dev, 1, &priv->vq);
113 	if (ret)
114 		return ret;
115 
116 	desc->blksz = 512;
117 	virtio_cread(dev, struct virtio_blk_config, capacity, &cap);
118 	desc->lba = cap;
119 
120 	return 0;
121 }
122 
123 static const struct blk_ops virtio_blk_ops = {
124 	.read	= virtio_blk_read,
125 	.write	= virtio_blk_write,
126 };
127 
128 U_BOOT_DRIVER(virtio_blk) = {
129 	.name	= VIRTIO_BLK_DRV_NAME,
130 	.id	= UCLASS_BLK,
131 	.ops	= &virtio_blk_ops,
132 	.bind	= virtio_blk_bind,
133 	.probe	= virtio_blk_probe,
134 	.remove	= virtio_reset,
135 	.priv_auto_alloc_size = sizeof(struct virtio_blk_priv),
136 	.flags	= DM_FLAG_ACTIVE_DMA,
137 };
138