1 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
2 /*
3  * Copyright 2013-2016 Freescale Semiconductor Inc.
4  *
5  * I/O services to send MC commands to the MC hardware
6  *
7  */
8 
9 #include <linux/delay.h>
10 #include <linux/slab.h>
11 #include <linux/ioport.h>
12 #include <linux/device.h>
13 #include <linux/io.h>
14 #include <linux/io-64-nonatomic-hi-lo.h>
15 #include <linux/fsl/mc.h>
16 
17 #include "fsl-mc-private.h"
18 
19 /*
20  * Timeout in milliseconds to wait for the completion of an MC command
21  */
22 #define MC_CMD_COMPLETION_TIMEOUT_MS	500
23 
24 /*
25  * usleep_range() min and max values used to throttle down polling
26  * iterations while waiting for MC command completion
27  */
28 #define MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS    10
29 #define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500
30 
mc_cmd_hdr_read_status(struct fsl_mc_command * cmd)31 static enum mc_cmd_status mc_cmd_hdr_read_status(struct fsl_mc_command *cmd)
32 {
33 	struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
34 
35 	return (enum mc_cmd_status)hdr->status;
36 }
37 
mc_cmd_hdr_read_cmdid(struct fsl_mc_command * cmd)38 u16 mc_cmd_hdr_read_cmdid(struct fsl_mc_command *cmd)
39 {
40 	struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
41 	u16 cmd_id = le16_to_cpu(hdr->cmd_id);
42 
43 	return cmd_id;
44 }
45 
mc_status_to_error(enum mc_cmd_status status)46 static int mc_status_to_error(enum mc_cmd_status status)
47 {
48 	static const int mc_status_to_error_map[] = {
49 		[MC_CMD_STATUS_OK] = 0,
50 		[MC_CMD_STATUS_AUTH_ERR] = -EACCES,
51 		[MC_CMD_STATUS_NO_PRIVILEGE] = -EPERM,
52 		[MC_CMD_STATUS_DMA_ERR] = -EIO,
53 		[MC_CMD_STATUS_CONFIG_ERR] = -ENXIO,
54 		[MC_CMD_STATUS_TIMEOUT] = -ETIMEDOUT,
55 		[MC_CMD_STATUS_NO_RESOURCE] = -ENAVAIL,
56 		[MC_CMD_STATUS_NO_MEMORY] = -ENOMEM,
57 		[MC_CMD_STATUS_BUSY] = -EBUSY,
58 		[MC_CMD_STATUS_UNSUPPORTED_OP] = -ENOTSUPP,
59 		[MC_CMD_STATUS_INVALID_STATE] = -ENODEV,
60 	};
61 
62 	if ((u32)status >= ARRAY_SIZE(mc_status_to_error_map))
63 		return -EINVAL;
64 
65 	return mc_status_to_error_map[status];
66 }
67 
mc_status_to_string(enum mc_cmd_status status)68 static const char *mc_status_to_string(enum mc_cmd_status status)
69 {
70 	static const char *const status_strings[] = {
71 		[MC_CMD_STATUS_OK] = "Command completed successfully",
72 		[MC_CMD_STATUS_READY] = "Command ready to be processed",
73 		[MC_CMD_STATUS_AUTH_ERR] = "Authentication error",
74 		[MC_CMD_STATUS_NO_PRIVILEGE] = "No privilege",
75 		[MC_CMD_STATUS_DMA_ERR] = "DMA or I/O error",
76 		[MC_CMD_STATUS_CONFIG_ERR] = "Configuration error",
77 		[MC_CMD_STATUS_TIMEOUT] = "Operation timed out",
78 		[MC_CMD_STATUS_NO_RESOURCE] = "No resources",
79 		[MC_CMD_STATUS_NO_MEMORY] = "No memory available",
80 		[MC_CMD_STATUS_BUSY] = "Device is busy",
81 		[MC_CMD_STATUS_UNSUPPORTED_OP] = "Unsupported operation",
82 		[MC_CMD_STATUS_INVALID_STATE] = "Invalid state"
83 	};
84 
85 	if ((unsigned int)status >= ARRAY_SIZE(status_strings))
86 		return "Unknown MC error";
87 
88 	return status_strings[status];
89 }
90 
91 /**
92  * mc_write_command - writes a command to a Management Complex (MC) portal
93  *
94  * @portal: pointer to an MC portal
95  * @cmd: pointer to a filled command
96  */
mc_write_command(struct fsl_mc_command __iomem * portal,struct fsl_mc_command * cmd)97 static inline void mc_write_command(struct fsl_mc_command __iomem *portal,
98 				    struct fsl_mc_command *cmd)
99 {
100 	int i;
101 
102 	/* copy command parameters into the portal */
103 	for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
104 		/*
105 		 * Data is already in the expected LE byte-order. Do an
106 		 * extra LE -> CPU conversion so that the CPU -> LE done in
107 		 * the device io write api puts it back in the right order.
108 		 */
109 		writeq_relaxed(le64_to_cpu(cmd->params[i]), &portal->params[i]);
110 
111 	/* submit the command by writing the header */
112 	writeq(le64_to_cpu(cmd->header), &portal->header);
113 }
114 
115 /**
116  * mc_read_response - reads the response for the last MC command from a
117  * Management Complex (MC) portal
118  *
119  * @portal: pointer to an MC portal
120  * @resp: pointer to command response buffer
121  *
122  * Returns MC_CMD_STATUS_OK on Success; Error code otherwise.
123  */
mc_read_response(struct fsl_mc_command __iomem * portal,struct fsl_mc_command * resp)124 static inline enum mc_cmd_status mc_read_response(struct fsl_mc_command __iomem
125 						  *portal,
126 						  struct fsl_mc_command *resp)
127 {
128 	int i;
129 	enum mc_cmd_status status;
130 
131 	/* Copy command response header from MC portal: */
132 	resp->header = cpu_to_le64(readq_relaxed(&portal->header));
133 	status = mc_cmd_hdr_read_status(resp);
134 	if (status != MC_CMD_STATUS_OK)
135 		return status;
136 
137 	/* Copy command response data from MC portal: */
138 	for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
139 		/*
140 		 * Data is expected to be in LE byte-order. Do an
141 		 * extra CPU -> LE to revert the LE -> CPU done in
142 		 * the device io read api.
143 		 */
144 		resp->params[i] =
145 			cpu_to_le64(readq_relaxed(&portal->params[i]));
146 
147 	return status;
148 }
149 
150 /**
151  * mc_polling_wait_preemptible() - Waits for the completion of an MC
152  *                                 command doing preemptible polling.
153  *                                 uslepp_range() is called between
154  *                                 polling iterations.
155  * @mc_io: MC I/O object to be used
156  * @cmd: command buffer to receive MC response
157  * @mc_status: MC command completion status
158  */
mc_polling_wait_preemptible(struct fsl_mc_io * mc_io,struct fsl_mc_command * cmd,enum mc_cmd_status * mc_status)159 static int mc_polling_wait_preemptible(struct fsl_mc_io *mc_io,
160 				       struct fsl_mc_command *cmd,
161 				       enum mc_cmd_status *mc_status)
162 {
163 	enum mc_cmd_status status;
164 	unsigned long jiffies_until_timeout =
165 		jiffies + msecs_to_jiffies(MC_CMD_COMPLETION_TIMEOUT_MS);
166 
167 	/*
168 	 * Wait for response from the MC hardware:
169 	 */
170 	for (;;) {
171 		status = mc_read_response(mc_io->portal_virt_addr, cmd);
172 		if (status != MC_CMD_STATUS_READY)
173 			break;
174 
175 		/*
176 		 * TODO: When MC command completion interrupts are supported
177 		 * call wait function here instead of usleep_range()
178 		 */
179 		usleep_range(MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS,
180 			     MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
181 
182 		if (time_after_eq(jiffies, jiffies_until_timeout)) {
183 			dev_dbg(mc_io->dev,
184 				"MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
185 				 &mc_io->portal_phys_addr,
186 				 (unsigned int)mc_cmd_hdr_read_token(cmd),
187 				 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
188 
189 			return -ETIMEDOUT;
190 		}
191 	}
192 
193 	*mc_status = status;
194 	return 0;
195 }
196 
197 /**
198  * mc_polling_wait_atomic() - Waits for the completion of an MC command
199  *                            doing atomic polling. udelay() is called
200  *                            between polling iterations.
201  * @mc_io: MC I/O object to be used
202  * @cmd: command buffer to receive MC response
203  * @mc_status: MC command completion status
204  */
mc_polling_wait_atomic(struct fsl_mc_io * mc_io,struct fsl_mc_command * cmd,enum mc_cmd_status * mc_status)205 static int mc_polling_wait_atomic(struct fsl_mc_io *mc_io,
206 				  struct fsl_mc_command *cmd,
207 				  enum mc_cmd_status *mc_status)
208 {
209 	enum mc_cmd_status status;
210 	unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;
211 
212 	BUILD_BUG_ON((MC_CMD_COMPLETION_TIMEOUT_MS * 1000) %
213 		     MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS != 0);
214 
215 	for (;;) {
216 		status = mc_read_response(mc_io->portal_virt_addr, cmd);
217 		if (status != MC_CMD_STATUS_READY)
218 			break;
219 
220 		udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
221 		timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
222 		if (timeout_usecs == 0) {
223 			dev_dbg(mc_io->dev,
224 				"MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
225 				 &mc_io->portal_phys_addr,
226 				 (unsigned int)mc_cmd_hdr_read_token(cmd),
227 				 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
228 
229 			return -ETIMEDOUT;
230 		}
231 	}
232 
233 	*mc_status = status;
234 	return 0;
235 }
236 
237 /**
238  * mc_send_command() - Sends a command to the MC device using the given
239  *                     MC I/O object
240  * @mc_io: MC I/O object to be used
241  * @cmd: command to be sent
242  *
243  * Returns '0' on Success; Error code otherwise.
244  */
mc_send_command(struct fsl_mc_io * mc_io,struct fsl_mc_command * cmd)245 int mc_send_command(struct fsl_mc_io *mc_io, struct fsl_mc_command *cmd)
246 {
247 	int error;
248 	enum mc_cmd_status status;
249 	unsigned long irq_flags = 0;
250 
251 	if (in_irq() && !(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
252 		return -EINVAL;
253 
254 	if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
255 		raw_spin_lock_irqsave(&mc_io->spinlock, irq_flags);
256 	else
257 		mutex_lock(&mc_io->mutex);
258 
259 	/*
260 	 * Send command to the MC hardware:
261 	 */
262 	mc_write_command(mc_io->portal_virt_addr, cmd);
263 
264 	/*
265 	 * Wait for response from the MC hardware:
266 	 */
267 	if (!(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
268 		error = mc_polling_wait_preemptible(mc_io, cmd, &status);
269 	else
270 		error = mc_polling_wait_atomic(mc_io, cmd, &status);
271 
272 	if (error < 0)
273 		goto common_exit;
274 
275 	if (status != MC_CMD_STATUS_OK) {
276 		dev_dbg(mc_io->dev,
277 			"MC command failed: portal: %pa, dprc handle: %#x, command: %#x, status: %s (%#x)\n",
278 			 &mc_io->portal_phys_addr,
279 			 (unsigned int)mc_cmd_hdr_read_token(cmd),
280 			 (unsigned int)mc_cmd_hdr_read_cmdid(cmd),
281 			 mc_status_to_string(status),
282 			 (unsigned int)status);
283 
284 		error = mc_status_to_error(status);
285 		goto common_exit;
286 	}
287 
288 	error = 0;
289 common_exit:
290 	if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
291 		raw_spin_unlock_irqrestore(&mc_io->spinlock, irq_flags);
292 	else
293 		mutex_unlock(&mc_io->mutex);
294 
295 	return error;
296 }
297 EXPORT_SYMBOL_GPL(mc_send_command);
298