summaryrefslogtreecommitdiffstats
path: root/drivers/bus/fsl-mc/mc-sys.c
blob: f2052cd0a0517865f73b778ca7b9b395c9886c4c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
/*
 * Copyright 2013-2016 Freescale Semiconductor Inc.
 *
 * I/O services to send MC commands to the MC hardware
 *
 */

#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/io-64-nonatomic-hi-lo.h>
#include <linux/fsl/mc.h>

#include "fsl-mc-private.h"

/*
 * Timeout in milliseconds to wait for the completion of an MC command
 */
#define MC_CMD_COMPLETION_TIMEOUT_MS	500

/*
 * usleep_range() min and max values used to throttle down polling
 * iterations while waiting for MC command completion
 */
#define MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS    10
#define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500

static enum mc_cmd_status mc_cmd_hdr_read_status(struct fsl_mc_command *cmd)
{
	struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;

	return (enum mc_cmd_status)hdr->status;
}

u16 mc_cmd_hdr_read_cmdid(struct fsl_mc_command *cmd)
{
	struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
	u16 cmd_id = le16_to_cpu(hdr->cmd_id);

	return cmd_id;
}

static int mc_status_to_error(enum mc_cmd_status status)
{
	static const int mc_status_to_error_map[] = {
		[MC_CMD_STATUS_OK] = 0,
		[MC_CMD_STATUS_AUTH_ERR] = -EACCES,
		[MC_CMD_STATUS_NO_PRIVILEGE] = -EPERM,
		[MC_CMD_STATUS_DMA_ERR] = -EIO,
		[MC_CMD_STATUS_CONFIG_ERR] = -ENXIO,
		[MC_CMD_STATUS_TIMEOUT] = -ETIMEDOUT,
		[MC_CMD_STATUS_NO_RESOURCE] = -ENAVAIL,
		[MC_CMD_STATUS_NO_MEMORY] = -ENOMEM,
		[MC_CMD_STATUS_BUSY] = -EBUSY,
		[MC_CMD_STATUS_UNSUPPORTED_OP] = -ENOTSUPP,
		[MC_CMD_STATUS_INVALID_STATE] = -ENODEV,
	};

	if ((u32)status >= ARRAY_SIZE(mc_status_to_error_map))
		return -EINVAL;

	return mc_status_to_error_map[status];
}

static const char *mc_status_to_string(enum mc_cmd_status status)
{
	static const char *const status_strings[] = {
		[MC_CMD_STATUS_OK] = "Command completed successfully",
		[MC_CMD_STATUS_READY] = "Command ready to be processed",
		[MC_CMD_STATUS_AUTH_ERR] = "Authentication error",
		[MC_CMD_STATUS_NO_PRIVILEGE] = "No privilege",
		[MC_CMD_STATUS_DMA_ERR] = "DMA or I/O error",
		[MC_CMD_STATUS_CONFIG_ERR] = "Configuration error",
		[MC_CMD_STATUS_TIMEOUT] = "Operation timed out",
		[MC_CMD_STATUS_NO_RESOURCE] = "No resources",
		[MC_CMD_STATUS_NO_MEMORY] = "No memory available",
		[MC_CMD_STATUS_BUSY] = "Device is busy",
		[MC_CMD_STATUS_UNSUPPORTED_OP] = "Unsupported operation",
		[MC_CMD_STATUS_INVALID_STATE] = "Invalid state"
	};

	if ((unsigned int)status >= ARRAY_SIZE(status_strings))
		return "Unknown MC error";

	return status_strings[status];
}

/**
 * mc_write_command - writes a command to a Management Complex (MC) portal
 *
 * @portal: pointer to an MC portal
 * @cmd: pointer to a filled command
 */
static inline void mc_write_command(struct fsl_mc_command __iomem *portal,
				    struct fsl_mc_command *cmd)
{
	int i;

	/* copy command parameters into the portal */
	for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
		/*
		 * Data is already in the expected LE byte-order. Do an
		 * extra LE -> CPU conversion so that the CPU -> LE done in
		 * the device io write api puts it back in the right order.
		 */
		writeq_relaxed(le64_to_cpu(cmd->params[i]), &portal->params[i]);

	/* submit the command by writing the header */
	writeq(le64_to_cpu(cmd->header), &portal->header);
}

/**
 * mc_read_response - reads the response for the last MC command from a
 * Management Complex (MC) portal
 *
 * @portal: pointer to an MC portal
 * @resp: pointer to command response buffer
 *
 * Returns MC_CMD_STATUS_OK on Success; Error code otherwise.
 */
static inline enum mc_cmd_status mc_read_response(struct fsl_mc_command __iomem
						  *portal,
						  struct fsl_mc_command *resp)
{
	int i;
	enum mc_cmd_status status;

	/* Copy command response header from MC portal: */
	resp->header = cpu_to_le64(readq_relaxed(&portal->header));
	status = mc_cmd_hdr_read_status(resp);
	if (status != MC_CMD_STATUS_OK)
		return status;

	/* Copy command response data from MC portal: */
	for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
		/*
		 * Data is expected to be in LE byte-order. Do an
		 * extra CPU -> LE to revert the LE -> CPU done in
		 * the device io read api.
		 */
		resp->params[i] =
			cpu_to_le64(readq_relaxed(&portal->params[i]));

	return status;
}

/**
 * mc_polling_wait_preemptible() - Waits for the completion of an MC
 *                                 command doing preemptible polling.
 *                                 uslepp_range() is called between
 *                                 polling iterations.
 * @mc_io: MC I/O object to be used
 * @cmd: command buffer to receive MC response
 * @mc_status: MC command completion status
 */
static int mc_polling_wait_preemptible(struct fsl_mc_io *mc_io,
				       struct fsl_mc_command *cmd,
				       enum mc_cmd_status *mc_status)
{
	enum mc_cmd_status status;
	unsigned long jiffies_until_timeout =
		jiffies + msecs_to_jiffies(MC_CMD_COMPLETION_TIMEOUT_MS);

	/*
	 * Wait for response from the MC hardware:
	 */
	for (;;) {
		status = mc_read_response(mc_io->portal_virt_addr, cmd);
		if (status != MC_CMD_STATUS_READY)
			break;

		/*
		 * TODO: When MC command completion interrupts are supported
		 * call wait function here instead of usleep_range()
		 */
		usleep_range(MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS,
			     MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);

		if (time_after_eq(jiffies, jiffies_until_timeout)) {
			dev_dbg(mc_io->dev,
				"MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
				 &mc_io->portal_phys_addr,
				 (unsigned int)mc_cmd_hdr_read_token(cmd),
				 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));

			return -ETIMEDOUT;
		}
	}

	*mc_status = status;
	return 0;
}

/**
 * mc_polling_wait_atomic() - Waits for the completion of an MC command
 *                            doing atomic polling. udelay() is called
 *                            between polling iterations.
 * @mc_io: MC I/O object to be used
 * @cmd: command buffer to receive MC response
 * @mc_status: MC command completion status
 */
static int mc_polling_wait_atomic(struct fsl_mc_io *mc_io,
				  struct fsl_mc_command *cmd,
				  enum mc_cmd_status *mc_status)
{
	enum mc_cmd_status status;
	unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;

	BUILD_BUG_ON((MC_CMD_COMPLETION_TIMEOUT_MS * 1000) %
		     MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS != 0);

	for (;;) {
		status = mc_read_response(mc_io->portal_virt_addr, cmd);
		if (status != MC_CMD_STATUS_READY)
			break;

		udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
		timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
		if (timeout_usecs == 0) {
			dev_dbg(mc_io->dev,
				"MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
				 &mc_io->portal_phys_addr,
				 (unsigned int)mc_cmd_hdr_read_token(cmd),
				 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));

			return -ETIMEDOUT;
		}
	}

	*mc_status = status;
	return 0;
}

/**
 * mc_send_command() - Sends a command to the MC device using the given
 *                     MC I/O object
 * @mc_io: MC I/O object to be used
 * @cmd: command to be sent
 *
 * Returns '0' on Success; Error code otherwise.
 */
int mc_send_command(struct fsl_mc_io *mc_io, struct fsl_mc_command *cmd)
{
	int error;
	enum mc_cmd_status status;
	unsigned long irq_flags = 0;

	if (in_irq() && !(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
		return -EINVAL;

	if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
		raw_spin_lock_irqsave(&mc_io->spinlock, irq_flags);
	else
		mutex_lock(&mc_io->mutex);

	/*
	 * Send command to the MC hardware:
	 */
	mc_write_command(mc_io->portal_virt_addr, cmd);

	/*
	 * Wait for response from the MC hardware:
	 */
	if (!(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
		error = mc_polling_wait_preemptible(mc_io, cmd, &status);
	else
		error = mc_polling_wait_atomic(mc_io, cmd, &status);

	if (error < 0)
		goto common_exit;

	if (status != MC_CMD_STATUS_OK) {
		dev_dbg(mc_io->dev,
			"MC command failed: portal: %pa, dprc handle: %#x, command: %#x, status: %s (%#x)\n",
			 &mc_io->portal_phys_addr,
			 (unsigned int)mc_cmd_hdr_read_token(cmd),
			 (unsigned int)mc_cmd_hdr_read_cmdid(cmd),
			 mc_status_to_string(status),
			 (unsigned int)status);

		error = mc_status_to_error(status);
		goto common_exit;
	}

	error = 0;
common_exit:
	if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
		raw_spin_unlock_irqrestore(&mc_io->spinlock, irq_flags);
	else
		mutex_unlock(&mc_io->mutex);

	return error;
}
EXPORT_SYMBOL_GPL(mc_send_command);