xref: /openbmc/linux/drivers/hwtracing/intel_th/sth.c (revision ba61bb17)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Intel(R) Trace Hub Software Trace Hub support
4  *
5  * Copyright (C) 2014-2015 Intel Corporation.
6  */
7 
8 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
9 
10 #include <linux/types.h>
11 #include <linux/module.h>
12 #include <linux/device.h>
13 #include <linux/io.h>
14 #include <linux/mm.h>
15 #include <linux/slab.h>
16 #include <linux/stm.h>
17 
18 #include "intel_th.h"
19 #include "sth.h"
20 
21 struct sth_device {
22 	void __iomem	*base;
23 	void __iomem	*channels;
24 	phys_addr_t	channels_phys;
25 	struct device	*dev;
26 	struct stm_data	stm;
27 	unsigned int	sw_nmasters;
28 };
29 
30 static struct intel_th_channel __iomem *
31 sth_channel(struct sth_device *sth, unsigned int master, unsigned int channel)
32 {
33 	struct intel_th_channel __iomem *sw_map = sth->channels;
34 
35 	return &sw_map[(master - sth->stm.sw_start) * sth->stm.sw_nchannels +
36 		       channel];
37 }
38 
39 static void sth_iowrite(void __iomem *dest, const unsigned char *payload,
40 			unsigned int size)
41 {
42 	switch (size) {
43 #ifdef CONFIG_64BIT
44 	case 8:
45 		writeq_relaxed(*(u64 *)payload, dest);
46 		break;
47 #endif
48 	case 4:
49 		writel_relaxed(*(u32 *)payload, dest);
50 		break;
51 	case 2:
52 		writew_relaxed(*(u16 *)payload, dest);
53 		break;
54 	case 1:
55 		writeb_relaxed(*(u8 *)payload, dest);
56 		break;
57 	default:
58 		break;
59 	}
60 }
61 
62 static ssize_t notrace sth_stm_packet(struct stm_data *stm_data,
63 				      unsigned int master,
64 				      unsigned int channel,
65 				      unsigned int packet,
66 				      unsigned int flags,
67 				      unsigned int size,
68 				      const unsigned char *payload)
69 {
70 	struct sth_device *sth = container_of(stm_data, struct sth_device, stm);
71 	struct intel_th_channel __iomem *out =
72 		sth_channel(sth, master, channel);
73 	u64 __iomem *outp = &out->Dn;
74 	unsigned long reg = REG_STH_TRIG;
75 
76 #ifndef CONFIG_64BIT
77 	if (size > 4)
78 		size = 4;
79 #endif
80 
81 	size = rounddown_pow_of_two(size);
82 
83 	switch (packet) {
84 	/* Global packets (GERR, XSYNC, TRIG) are sent with register writes */
85 	case STP_PACKET_GERR:
86 		reg += 4;
87 	case STP_PACKET_XSYNC:
88 		reg += 8;
89 	case STP_PACKET_TRIG:
90 		if (flags & STP_PACKET_TIMESTAMPED)
91 			reg += 4;
92 		writeb_relaxed(*payload, sth->base + reg);
93 		break;
94 
95 	case STP_PACKET_MERR:
96 		if (size > 4)
97 			size = 4;
98 
99 		sth_iowrite(&out->MERR, payload, size);
100 		break;
101 
102 	case STP_PACKET_FLAG:
103 		if (flags & STP_PACKET_TIMESTAMPED)
104 			outp = (u64 __iomem *)&out->FLAG_TS;
105 		else
106 			outp = (u64 __iomem *)&out->FLAG;
107 
108 		size = 0;
109 		writeb_relaxed(0, outp);
110 		break;
111 
112 	case STP_PACKET_USER:
113 		if (flags & STP_PACKET_TIMESTAMPED)
114 			outp = &out->USER_TS;
115 		else
116 			outp = &out->USER;
117 		sth_iowrite(outp, payload, size);
118 		break;
119 
120 	case STP_PACKET_DATA:
121 		outp = &out->Dn;
122 
123 		if (flags & STP_PACKET_TIMESTAMPED)
124 			outp += 2;
125 		if (flags & STP_PACKET_MARKED)
126 			outp++;
127 
128 		sth_iowrite(outp, payload, size);
129 		break;
130 	default:
131 		return -ENOTSUPP;
132 	}
133 
134 	return size;
135 }
136 
137 static phys_addr_t
138 sth_stm_mmio_addr(struct stm_data *stm_data, unsigned int master,
139 		  unsigned int channel, unsigned int nr_chans)
140 {
141 	struct sth_device *sth = container_of(stm_data, struct sth_device, stm);
142 	phys_addr_t addr;
143 
144 	master -= sth->stm.sw_start;
145 	addr = sth->channels_phys + (master * sth->stm.sw_nchannels + channel) *
146 		sizeof(struct intel_th_channel);
147 
148 	if (offset_in_page(addr) ||
149 	    offset_in_page(nr_chans * sizeof(struct intel_th_channel)))
150 		return 0;
151 
152 	return addr;
153 }
154 
155 static int sth_stm_link(struct stm_data *stm_data, unsigned int master,
156 			 unsigned int channel)
157 {
158 	struct sth_device *sth = container_of(stm_data, struct sth_device, stm);
159 
160 	intel_th_set_output(to_intel_th_device(sth->dev), master);
161 
162 	return 0;
163 }
164 
165 static int intel_th_sw_init(struct sth_device *sth)
166 {
167 	u32 reg;
168 
169 	reg = ioread32(sth->base + REG_STH_STHCAP1);
170 	sth->stm.sw_nchannels = reg & 0xff;
171 
172 	reg = ioread32(sth->base + REG_STH_STHCAP0);
173 	sth->stm.sw_start = reg & 0xffff;
174 	sth->stm.sw_end = reg >> 16;
175 
176 	sth->sw_nmasters = sth->stm.sw_end - sth->stm.sw_start;
177 	dev_dbg(sth->dev, "sw_start: %x sw_end: %x masters: %x nchannels: %x\n",
178 		sth->stm.sw_start, sth->stm.sw_end, sth->sw_nmasters,
179 		sth->stm.sw_nchannels);
180 
181 	return 0;
182 }
183 
184 static int intel_th_sth_probe(struct intel_th_device *thdev)
185 {
186 	struct device *dev = &thdev->dev;
187 	struct sth_device *sth;
188 	struct resource *res;
189 	void __iomem *base, *channels;
190 	int err;
191 
192 	res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 0);
193 	if (!res)
194 		return -ENODEV;
195 
196 	base = devm_ioremap(dev, res->start, resource_size(res));
197 	if (!base)
198 		return -ENOMEM;
199 
200 	res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 1);
201 	if (!res)
202 		return -ENODEV;
203 
204 	channels = devm_ioremap(dev, res->start, resource_size(res));
205 	if (!channels)
206 		return -ENOMEM;
207 
208 	sth = devm_kzalloc(dev, sizeof(*sth), GFP_KERNEL);
209 	if (!sth)
210 		return -ENOMEM;
211 
212 	sth->dev = dev;
213 	sth->base = base;
214 	sth->channels = channels;
215 	sth->channels_phys = res->start;
216 	sth->stm.name = dev_name(dev);
217 	sth->stm.packet = sth_stm_packet;
218 	sth->stm.mmio_addr = sth_stm_mmio_addr;
219 	sth->stm.sw_mmiosz = sizeof(struct intel_th_channel);
220 	sth->stm.link = sth_stm_link;
221 
222 	err = intel_th_sw_init(sth);
223 	if (err)
224 		return err;
225 
226 	err = stm_register_device(dev, &sth->stm, THIS_MODULE);
227 	if (err) {
228 		dev_err(dev, "stm_register_device failed\n");
229 		return err;
230 	}
231 
232 	dev_set_drvdata(dev, sth);
233 
234 	return 0;
235 }
236 
237 static void intel_th_sth_remove(struct intel_th_device *thdev)
238 {
239 	struct sth_device *sth = dev_get_drvdata(&thdev->dev);
240 
241 	stm_unregister_device(&sth->stm);
242 }
243 
244 static struct intel_th_driver intel_th_sth_driver = {
245 	.probe	= intel_th_sth_probe,
246 	.remove	= intel_th_sth_remove,
247 	.driver	= {
248 		.name	= "sth",
249 		.owner	= THIS_MODULE,
250 	},
251 };
252 
253 module_driver(intel_th_sth_driver,
254 	      intel_th_driver_register,
255 	      intel_th_driver_unregister);
256 
257 MODULE_LICENSE("GPL v2");
258 MODULE_DESCRIPTION("Intel(R) Trace Hub Software Trace Hub driver");
259 MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@intel.com>");
260