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(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(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(&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(udev, &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