1/* SPDX-License-Identifier: GPL-2.0 */
2#include <linux/usb.h>
3#include <linux/usb/hcd.h>
4#include "usb.h"
5
6static int uas_is_interface(struct usb_host_interface *intf)
7{
8 return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE &&
9 intf->desc.bInterfaceSubClass == USB_SC_SCSI &&
10 intf->desc.bInterfaceProtocol == USB_PR_UAS);
11}
12
13static struct usb_host_interface *uas_find_uas_alt_setting(
14 struct usb_interface *intf)
15{
16 int i;
17
18 for (i = 0; i < intf->num_altsetting; i++) {
19 struct usb_host_interface *alt = &intf->altsetting[i];
20
21 if (uas_is_interface(intf: alt))
22 return alt;
23 }
24
25 return NULL;
26}
27
28static int uas_find_endpoints(struct usb_host_interface *alt,
29 struct usb_host_endpoint *eps[])
30{
31 struct usb_host_endpoint *endpoint = alt->endpoint;
32 unsigned i, n_endpoints = alt->desc.bNumEndpoints;
33
34 for (i = 0; i < n_endpoints; i++) {
35 unsigned char *extra = endpoint[i].extra;
36 int len = endpoint[i].extralen;
37 while (len >= 3) {
38 if (extra[1] == USB_DT_PIPE_USAGE) {
39 unsigned pipe_id = extra[2];
40 if (pipe_id > 0 && pipe_id < 5)
41 eps[pipe_id - 1] = &endpoint[i];
42 break;
43 }
44 len -= extra[0];
45 extra += extra[0];
46 }
47 }
48
49 if (!eps[0] || !eps[1] || !eps[2] || !eps[3])
50 return -ENODEV;
51
52 return 0;
53}
54
55static int uas_use_uas_driver(struct usb_interface *intf,
56 const struct usb_device_id *id,
57 u64 *flags_ret)
58{
59 struct usb_host_endpoint *eps[4] = { };
60 struct usb_device *udev = interface_to_usbdev(intf);
61 struct usb_hcd *hcd = bus_to_hcd(bus: udev->bus);
62 u64 flags = id->driver_info;
63 struct usb_host_interface *alt;
64 int r;
65
66 alt = uas_find_uas_alt_setting(intf);
67 if (!alt)
68 return 0;
69
70 r = uas_find_endpoints(alt, eps);
71 if (r < 0)
72 return 0;
73
74 /*
75 * ASMedia has a number of usb3 to sata bridge chips, at the time of
76 * this writing the following versions exist:
77 * ASM1051 - no uas support version
78 * ASM1051 - with broken (*) uas support
79 * ASM1053 - with working uas support, but problems with large xfers
80 * ASM1153 - with working uas support
81 *
82 * Devices with these chips re-use a number of device-ids over the
83 * entire line, so the device-id is useless to determine if we're
84 * dealing with an ASM1051 (which we want to avoid).
85 *
86 * The ASM1153 can be identified by config.MaxPower == 0,
87 * where as the ASM105x models have config.MaxPower == 36.
88 *
89 * Differentiating between the ASM1053 and ASM1051 is trickier, when
90 * connected over USB-3 we can look at the number of streams supported,
91 * ASM1051 supports 32 streams, where as early ASM1053 versions support
92 * 16 streams, newer ASM1053-s also support 32 streams, but have a
93 * different prod-id.
94 *
95 * (*) ASM1051 chips do work with UAS with some disks (with the
96 * US_FL_NO_REPORT_OPCODES quirk), but are broken with other disks
97 */
98 if (le16_to_cpu(udev->descriptor.idVendor) == 0x174c &&
99 (le16_to_cpu(udev->descriptor.idProduct) == 0x5106 ||
100 le16_to_cpu(udev->descriptor.idProduct) == 0x55aa)) {
101 if (udev->actconfig->desc.bMaxPower == 0) {
102 /* ASM1153, do nothing */
103 } else if (udev->speed < USB_SPEED_SUPER) {
104 /* No streams info, assume ASM1051 */
105 flags |= US_FL_IGNORE_UAS;
106 } else if (usb_ss_max_streams(comp: &eps[1]->ss_ep_comp) == 32) {
107 /* Possibly an ASM1051, disable uas */
108 flags |= US_FL_IGNORE_UAS;
109 } else {
110 /* ASM1053, these have issues with large transfers */
111 flags |= US_FL_MAX_SECTORS_240;
112 }
113 }
114
115 /* All Seagate disk enclosures have broken ATA pass-through support */
116 if (le16_to_cpu(udev->descriptor.idVendor) == 0x0bc2)
117 flags |= US_FL_NO_ATA_1X;
118
119 /*
120 * RTL9210-based enclosure from HIKSEMI, MD202 reportedly have issues
121 * with UAS. This isn't distinguishable with just idVendor and
122 * idProduct, use manufacturer and product too.
123 *
124 * Reported-by: Hongling Zeng <zenghongling@kylinos.cn>
125 */
126 if (le16_to_cpu(udev->descriptor.idVendor) == 0x0bda &&
127 le16_to_cpu(udev->descriptor.idProduct) == 0x9210 &&
128 (udev->manufacturer && !strcmp(udev->manufacturer, "HIKSEMI")) &&
129 (udev->product && !strcmp(udev->product, "MD202")))
130 flags |= US_FL_IGNORE_UAS;
131
132 usb_stor_adjust_quirks(dev: udev, fflags: &flags);
133
134 if (flags & US_FL_IGNORE_UAS) {
135 dev_warn(&udev->dev,
136 "UAS is ignored for this device, using usb-storage instead\n");
137 return 0;
138 }
139
140 if (udev->bus->sg_tablesize == 0) {
141 dev_warn(&udev->dev,
142 "The driver for the USB controller %s does not support scatter-gather which is\n",
143 hcd->driver->description);
144 dev_warn(&udev->dev,
145 "required by the UAS driver. Please try an other USB controller if you wish to use UAS.\n");
146 return 0;
147 }
148
149 if (udev->speed >= USB_SPEED_SUPER && !hcd->can_do_streams) {
150 dev_warn(&udev->dev,
151 "USB controller %s does not support streams, which are required by the UAS driver.\n",
152 hcd_to_bus(hcd)->bus_name);
153 dev_warn(&udev->dev,
154 "Please try an other USB controller if you wish to use UAS.\n");
155 return 0;
156 }
157
158 if (flags_ret)
159 *flags_ret = flags;
160
161 return 1;
162}
163

source code of linux/drivers/usb/storage/uas-detect.h