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
31static 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
38u16 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
46static 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
68static 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 */
97static 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), addr: &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 */
124static 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(cmd: 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 */
159static 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(portal: mc_io->portal_virt_addr, resp: 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 */
205static 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(portal: mc_io->portal_virt_addr, resp: 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 */
245int 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(portal: 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, mc_status: &status);
269 else
270 error = mc_polling_wait_atomic(mc_io, cmd, mc_status: &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;
289common_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(lock: &mc_io->mutex);
294
295 return error;
296}
297EXPORT_SYMBOL_GPL(mc_send_command);
298

source code of linux/drivers/bus/fsl-mc/mc-sys.c