xref: /openbmc/linux/drivers/mmc/core/host.c (revision 79e790ff)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/drivers/mmc/core/host.c
4  *
5  *  Copyright (C) 2003 Russell King, All Rights Reserved.
6  *  Copyright (C) 2007-2008 Pierre Ossman
7  *  Copyright (C) 2010 Linus Walleij
8  *
9  *  MMC host class device management
10  */
11 
12 #include <linux/device.h>
13 #include <linux/err.h>
14 #include <linux/idr.h>
15 #include <linux/of.h>
16 #include <linux/of_gpio.h>
17 #include <linux/pagemap.h>
18 #include <linux/pm_wakeup.h>
19 #include <linux/export.h>
20 #include <linux/leds.h>
21 #include <linux/slab.h>
22 
23 #include <linux/mmc/host.h>
24 #include <linux/mmc/card.h>
25 #include <linux/mmc/slot-gpio.h>
26 
27 #include "core.h"
28 #include "crypto.h"
29 #include "host.h"
30 #include "slot-gpio.h"
31 #include "pwrseq.h"
32 #include "sdio_ops.h"
33 
34 #define cls_dev_to_mmc_host(d)	container_of(d, struct mmc_host, class_dev)
35 
36 static DEFINE_IDA(mmc_host_ida);
37 
38 #ifdef CONFIG_PM_SLEEP
39 static int mmc_host_class_prepare(struct device *dev)
40 {
41 	struct mmc_host *host = cls_dev_to_mmc_host(dev);
42 
43 	/*
44 	 * It's safe to access the bus_ops pointer, as both userspace and the
45 	 * workqueue for detecting cards are frozen at this point.
46 	 */
47 	if (!host->bus_ops)
48 		return 0;
49 
50 	/* Validate conditions for system suspend. */
51 	if (host->bus_ops->pre_suspend)
52 		return host->bus_ops->pre_suspend(host);
53 
54 	return 0;
55 }
56 
57 static void mmc_host_class_complete(struct device *dev)
58 {
59 	struct mmc_host *host = cls_dev_to_mmc_host(dev);
60 
61 	_mmc_detect_change(host, 0, false);
62 }
63 
64 static const struct dev_pm_ops mmc_host_class_dev_pm_ops = {
65 	.prepare = mmc_host_class_prepare,
66 	.complete = mmc_host_class_complete,
67 };
68 
69 #define MMC_HOST_CLASS_DEV_PM_OPS (&mmc_host_class_dev_pm_ops)
70 #else
71 #define MMC_HOST_CLASS_DEV_PM_OPS NULL
72 #endif
73 
74 static void mmc_host_classdev_release(struct device *dev)
75 {
76 	struct mmc_host *host = cls_dev_to_mmc_host(dev);
77 	wakeup_source_unregister(host->ws);
78 	ida_simple_remove(&mmc_host_ida, host->index);
79 	kfree(host);
80 }
81 
82 static struct class mmc_host_class = {
83 	.name		= "mmc_host",
84 	.dev_release	= mmc_host_classdev_release,
85 	.pm		= MMC_HOST_CLASS_DEV_PM_OPS,
86 };
87 
88 int mmc_register_host_class(void)
89 {
90 	return class_register(&mmc_host_class);
91 }
92 
93 void mmc_unregister_host_class(void)
94 {
95 	class_unregister(&mmc_host_class);
96 }
97 
98 void mmc_retune_enable(struct mmc_host *host)
99 {
100 	host->can_retune = 1;
101 	if (host->retune_period)
102 		mod_timer(&host->retune_timer,
103 			  jiffies + host->retune_period * HZ);
104 }
105 
106 /*
107  * Pause re-tuning for a small set of operations.  The pause begins after the
108  * next command and after first doing re-tuning.
109  */
110 void mmc_retune_pause(struct mmc_host *host)
111 {
112 	if (!host->retune_paused) {
113 		host->retune_paused = 1;
114 		mmc_retune_needed(host);
115 		mmc_retune_hold(host);
116 	}
117 }
118 EXPORT_SYMBOL(mmc_retune_pause);
119 
120 void mmc_retune_unpause(struct mmc_host *host)
121 {
122 	if (host->retune_paused) {
123 		host->retune_paused = 0;
124 		mmc_retune_release(host);
125 	}
126 }
127 EXPORT_SYMBOL(mmc_retune_unpause);
128 
129 void mmc_retune_disable(struct mmc_host *host)
130 {
131 	mmc_retune_unpause(host);
132 	host->can_retune = 0;
133 	del_timer_sync(&host->retune_timer);
134 	host->retune_now = 0;
135 	host->need_retune = 0;
136 }
137 
138 void mmc_retune_timer_stop(struct mmc_host *host)
139 {
140 	del_timer_sync(&host->retune_timer);
141 }
142 EXPORT_SYMBOL(mmc_retune_timer_stop);
143 
144 void mmc_retune_hold(struct mmc_host *host)
145 {
146 	if (!host->hold_retune)
147 		host->retune_now = 1;
148 	host->hold_retune += 1;
149 }
150 
151 void mmc_retune_release(struct mmc_host *host)
152 {
153 	if (host->hold_retune)
154 		host->hold_retune -= 1;
155 	else
156 		WARN_ON(1);
157 }
158 EXPORT_SYMBOL(mmc_retune_release);
159 
160 int mmc_retune(struct mmc_host *host)
161 {
162 	bool return_to_hs400 = false;
163 	int err;
164 
165 	if (host->retune_now)
166 		host->retune_now = 0;
167 	else
168 		return 0;
169 
170 	if (!host->need_retune || host->doing_retune || !host->card)
171 		return 0;
172 
173 	host->need_retune = 0;
174 
175 	host->doing_retune = 1;
176 
177 	if (host->ios.timing == MMC_TIMING_MMC_HS400) {
178 		err = mmc_hs400_to_hs200(host->card);
179 		if (err)
180 			goto out;
181 
182 		return_to_hs400 = true;
183 	}
184 
185 	err = mmc_execute_tuning(host->card);
186 	if (err)
187 		goto out;
188 
189 	if (return_to_hs400)
190 		err = mmc_hs200_to_hs400(host->card);
191 out:
192 	host->doing_retune = 0;
193 
194 	return err;
195 }
196 
197 static void mmc_retune_timer(struct timer_list *t)
198 {
199 	struct mmc_host *host = from_timer(host, t, retune_timer);
200 
201 	mmc_retune_needed(host);
202 }
203 
204 static void mmc_of_parse_timing_phase(struct device *dev, const char *prop,
205 				      struct mmc_clk_phase *phase)
206 {
207 	int degrees[2] = {0};
208 	int rc;
209 
210 	rc = device_property_read_u32_array(dev, prop, degrees, 2);
211 	phase->valid = !rc;
212 	if (phase->valid) {
213 		phase->in_deg = degrees[0];
214 		phase->out_deg = degrees[1];
215 	}
216 }
217 
218 void
219 mmc_of_parse_clk_phase(struct mmc_host *host, struct mmc_clk_phase_map *map)
220 {
221 	struct device *dev = host->parent;
222 
223 	mmc_of_parse_timing_phase(dev, "clk-phase-legacy",
224 				  &map->phase[MMC_TIMING_LEGACY]);
225 	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs",
226 				  &map->phase[MMC_TIMING_MMC_HS]);
227 	mmc_of_parse_timing_phase(dev, "clk-phase-sd-hs",
228 				  &map->phase[MMC_TIMING_SD_HS]);
229 	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr12",
230 				  &map->phase[MMC_TIMING_UHS_SDR12]);
231 	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr25",
232 				  &map->phase[MMC_TIMING_UHS_SDR25]);
233 	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr50",
234 				  &map->phase[MMC_TIMING_UHS_SDR50]);
235 	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr104",
236 				  &map->phase[MMC_TIMING_UHS_SDR104]);
237 	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-ddr50",
238 				  &map->phase[MMC_TIMING_UHS_DDR50]);
239 	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-ddr52",
240 				  &map->phase[MMC_TIMING_MMC_DDR52]);
241 	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs200",
242 				  &map->phase[MMC_TIMING_MMC_HS200]);
243 	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs400",
244 				  &map->phase[MMC_TIMING_MMC_HS400]);
245 }
246 EXPORT_SYMBOL(mmc_of_parse_clk_phase);
247 
248 /**
249  * mmc_of_parse() - parse host's device properties
250  * @host: host whose properties should be parsed.
251  *
252  * To keep the rest of the MMC subsystem unaware of whether DT has been
253  * used to to instantiate and configure this host instance or not, we
254  * parse the properties and set respective generic mmc-host flags and
255  * parameters.
256  */
257 int mmc_of_parse(struct mmc_host *host)
258 {
259 	struct device *dev = host->parent;
260 	u32 bus_width, drv_type, cd_debounce_delay_ms;
261 	int ret;
262 
263 	if (!dev || !dev_fwnode(dev))
264 		return 0;
265 
266 	/* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
267 	if (device_property_read_u32(dev, "bus-width", &bus_width) < 0) {
268 		dev_dbg(host->parent,
269 			"\"bus-width\" property is missing, assuming 1 bit.\n");
270 		bus_width = 1;
271 	}
272 
273 	switch (bus_width) {
274 	case 8:
275 		host->caps |= MMC_CAP_8_BIT_DATA;
276 		fallthrough;	/* Hosts capable of 8-bit can also do 4 bits */
277 	case 4:
278 		host->caps |= MMC_CAP_4_BIT_DATA;
279 		break;
280 	case 1:
281 		break;
282 	default:
283 		dev_err(host->parent,
284 			"Invalid \"bus-width\" value %u!\n", bus_width);
285 		return -EINVAL;
286 	}
287 
288 	/* f_max is obtained from the optional "max-frequency" property */
289 	device_property_read_u32(dev, "max-frequency", &host->f_max);
290 
291 	/*
292 	 * Configure CD and WP pins. They are both by default active low to
293 	 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
294 	 * mmc-gpio helpers are used to attach, configure and use them. If
295 	 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
296 	 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
297 	 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
298 	 * is set. If the "non-removable" property is found, the
299 	 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
300 	 * configuration is performed.
301 	 */
302 
303 	/* Parse Card Detection */
304 
305 	if (device_property_read_bool(dev, "non-removable")) {
306 		host->caps |= MMC_CAP_NONREMOVABLE;
307 	} else {
308 		if (device_property_read_bool(dev, "cd-inverted"))
309 			host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
310 
311 		if (device_property_read_u32(dev, "cd-debounce-delay-ms",
312 					     &cd_debounce_delay_ms))
313 			cd_debounce_delay_ms = 200;
314 
315 		if (device_property_read_bool(dev, "broken-cd"))
316 			host->caps |= MMC_CAP_NEEDS_POLL;
317 
318 		ret = mmc_gpiod_request_cd(host, "cd", 0, false,
319 					   cd_debounce_delay_ms * 1000);
320 		if (!ret)
321 			dev_info(host->parent, "Got CD GPIO\n");
322 		else if (ret != -ENOENT && ret != -ENOSYS)
323 			return ret;
324 	}
325 
326 	/* Parse Write Protection */
327 
328 	if (device_property_read_bool(dev, "wp-inverted"))
329 		host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
330 
331 	ret = mmc_gpiod_request_ro(host, "wp", 0, 0);
332 	if (!ret)
333 		dev_info(host->parent, "Got WP GPIO\n");
334 	else if (ret != -ENOENT && ret != -ENOSYS)
335 		return ret;
336 
337 	if (device_property_read_bool(dev, "disable-wp"))
338 		host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
339 
340 	if (device_property_read_bool(dev, "cap-sd-highspeed"))
341 		host->caps |= MMC_CAP_SD_HIGHSPEED;
342 	if (device_property_read_bool(dev, "cap-mmc-highspeed"))
343 		host->caps |= MMC_CAP_MMC_HIGHSPEED;
344 	if (device_property_read_bool(dev, "sd-uhs-sdr12"))
345 		host->caps |= MMC_CAP_UHS_SDR12;
346 	if (device_property_read_bool(dev, "sd-uhs-sdr25"))
347 		host->caps |= MMC_CAP_UHS_SDR25;
348 	if (device_property_read_bool(dev, "sd-uhs-sdr50"))
349 		host->caps |= MMC_CAP_UHS_SDR50;
350 	if (device_property_read_bool(dev, "sd-uhs-sdr104"))
351 		host->caps |= MMC_CAP_UHS_SDR104;
352 	if (device_property_read_bool(dev, "sd-uhs-ddr50"))
353 		host->caps |= MMC_CAP_UHS_DDR50;
354 	if (device_property_read_bool(dev, "cap-power-off-card"))
355 		host->caps |= MMC_CAP_POWER_OFF_CARD;
356 	if (device_property_read_bool(dev, "cap-mmc-hw-reset"))
357 		host->caps |= MMC_CAP_HW_RESET;
358 	if (device_property_read_bool(dev, "cap-sdio-irq"))
359 		host->caps |= MMC_CAP_SDIO_IRQ;
360 	if (device_property_read_bool(dev, "full-pwr-cycle"))
361 		host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
362 	if (device_property_read_bool(dev, "full-pwr-cycle-in-suspend"))
363 		host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND;
364 	if (device_property_read_bool(dev, "keep-power-in-suspend"))
365 		host->pm_caps |= MMC_PM_KEEP_POWER;
366 	if (device_property_read_bool(dev, "wakeup-source") ||
367 	    device_property_read_bool(dev, "enable-sdio-wakeup")) /* legacy */
368 		host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
369 	if (device_property_read_bool(dev, "mmc-ddr-3_3v"))
370 		host->caps |= MMC_CAP_3_3V_DDR;
371 	if (device_property_read_bool(dev, "mmc-ddr-1_8v"))
372 		host->caps |= MMC_CAP_1_8V_DDR;
373 	if (device_property_read_bool(dev, "mmc-ddr-1_2v"))
374 		host->caps |= MMC_CAP_1_2V_DDR;
375 	if (device_property_read_bool(dev, "mmc-hs200-1_8v"))
376 		host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
377 	if (device_property_read_bool(dev, "mmc-hs200-1_2v"))
378 		host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
379 	if (device_property_read_bool(dev, "mmc-hs400-1_8v"))
380 		host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
381 	if (device_property_read_bool(dev, "mmc-hs400-1_2v"))
382 		host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
383 	if (device_property_read_bool(dev, "mmc-hs400-enhanced-strobe"))
384 		host->caps2 |= MMC_CAP2_HS400_ES;
385 	if (device_property_read_bool(dev, "no-sdio"))
386 		host->caps2 |= MMC_CAP2_NO_SDIO;
387 	if (device_property_read_bool(dev, "no-sd"))
388 		host->caps2 |= MMC_CAP2_NO_SD;
389 	if (device_property_read_bool(dev, "no-mmc"))
390 		host->caps2 |= MMC_CAP2_NO_MMC;
391 
392 	/* Must be after "non-removable" check */
393 	if (device_property_read_u32(dev, "fixed-emmc-driver-type", &drv_type) == 0) {
394 		if (host->caps & MMC_CAP_NONREMOVABLE)
395 			host->fixed_drv_type = drv_type;
396 		else
397 			dev_err(host->parent,
398 				"can't use fixed driver type, media is removable\n");
399 	}
400 
401 	host->dsr_req = !device_property_read_u32(dev, "dsr", &host->dsr);
402 	if (host->dsr_req && (host->dsr & ~0xffff)) {
403 		dev_err(host->parent,
404 			"device tree specified broken value for DSR: 0x%x, ignoring\n",
405 			host->dsr);
406 		host->dsr_req = 0;
407 	}
408 
409 	device_property_read_u32(dev, "post-power-on-delay-ms",
410 				 &host->ios.power_delay_ms);
411 
412 	return mmc_pwrseq_alloc(host);
413 }
414 
415 EXPORT_SYMBOL(mmc_of_parse);
416 
417 /**
418  * mmc_of_parse_voltage - return mask of supported voltages
419  * @host: host whose properties should be parsed.
420  * @mask: mask of voltages available for MMC/SD/SDIO
421  *
422  * Parse the "voltage-ranges" property, returning zero if it is not
423  * found, negative errno if the voltage-range specification is invalid,
424  * or one if the voltage-range is specified and successfully parsed.
425  */
426 int mmc_of_parse_voltage(struct mmc_host *host, u32 *mask)
427 {
428 	const char *prop = "voltage-ranges";
429 	struct device *dev = host->parent;
430 	u32 *voltage_ranges;
431 	int num_ranges, i;
432 	int ret;
433 
434 	if (!device_property_present(dev, prop)) {
435 		dev_dbg(dev, "%s unspecified\n", prop);
436 		return 0;
437 	}
438 
439 	ret = device_property_count_u32(dev, prop);
440 	if (ret < 0)
441 		return ret;
442 
443 	num_ranges = ret / 2;
444 	if (!num_ranges) {
445 		dev_err(dev, "%s empty\n", prop);
446 		return -EINVAL;
447 	}
448 
449 	voltage_ranges = kcalloc(2 * num_ranges, sizeof(*voltage_ranges), GFP_KERNEL);
450 	if (!voltage_ranges)
451 		return -ENOMEM;
452 
453 	ret = device_property_read_u32_array(dev, prop, voltage_ranges, 2 * num_ranges);
454 	if (ret) {
455 		kfree(voltage_ranges);
456 		return ret;
457 	}
458 
459 	for (i = 0; i < num_ranges; i++) {
460 		const int j = i * 2;
461 		u32 ocr_mask;
462 
463 		ocr_mask = mmc_vddrange_to_ocrmask(voltage_ranges[j + 0],
464 						   voltage_ranges[j + 1]);
465 		if (!ocr_mask) {
466 			dev_err(dev, "range #%d in %s is invalid\n", i, prop);
467 			kfree(voltage_ranges);
468 			return -EINVAL;
469 		}
470 		*mask |= ocr_mask;
471 	}
472 
473 	kfree(voltage_ranges);
474 
475 	return 1;
476 }
477 EXPORT_SYMBOL(mmc_of_parse_voltage);
478 
479 /**
480  * mmc_first_nonreserved_index() - get the first index that is not reserved
481  */
482 static int mmc_first_nonreserved_index(void)
483 {
484 	int max;
485 
486 	max = of_alias_get_highest_id("mmc");
487 	if (max < 0)
488 		return 0;
489 
490 	return max + 1;
491 }
492 
493 /**
494  *	mmc_alloc_host - initialise the per-host structure.
495  *	@extra: sizeof private data structure
496  *	@dev: pointer to host device model structure
497  *
498  *	Initialise the per-host structure.
499  */
500 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
501 {
502 	int err;
503 	struct mmc_host *host;
504 	int alias_id, min_idx, max_idx;
505 
506 	host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
507 	if (!host)
508 		return NULL;
509 
510 	/* scanning will be enabled when we're ready */
511 	host->rescan_disable = 1;
512 
513 	alias_id = of_alias_get_id(dev->of_node, "mmc");
514 	if (alias_id >= 0) {
515 		min_idx = alias_id;
516 		max_idx = alias_id + 1;
517 	} else {
518 		min_idx = mmc_first_nonreserved_index();
519 		max_idx = 0;
520 	}
521 
522 	err = ida_simple_get(&mmc_host_ida, min_idx, max_idx, GFP_KERNEL);
523 	if (err < 0) {
524 		kfree(host);
525 		return NULL;
526 	}
527 
528 	host->index = err;
529 
530 	dev_set_name(&host->class_dev, "mmc%d", host->index);
531 	host->ws = wakeup_source_register(NULL, dev_name(&host->class_dev));
532 
533 	host->parent = dev;
534 	host->class_dev.parent = dev;
535 	host->class_dev.class = &mmc_host_class;
536 	device_initialize(&host->class_dev);
537 	device_enable_async_suspend(&host->class_dev);
538 
539 	if (mmc_gpio_alloc(host)) {
540 		put_device(&host->class_dev);
541 		return NULL;
542 	}
543 
544 	spin_lock_init(&host->lock);
545 	init_waitqueue_head(&host->wq);
546 	INIT_DELAYED_WORK(&host->detect, mmc_rescan);
547 	INIT_DELAYED_WORK(&host->sdio_irq_work, sdio_irq_work);
548 	timer_setup(&host->retune_timer, mmc_retune_timer, 0);
549 
550 	/*
551 	 * By default, hosts do not support SGIO or large requests.
552 	 * They have to set these according to their abilities.
553 	 */
554 	host->max_segs = 1;
555 	host->max_seg_size = PAGE_SIZE;
556 
557 	host->max_req_size = PAGE_SIZE;
558 	host->max_blk_size = 512;
559 	host->max_blk_count = PAGE_SIZE / 512;
560 
561 	host->fixed_drv_type = -EINVAL;
562 	host->ios.power_delay_ms = 10;
563 	host->ios.power_mode = MMC_POWER_UNDEFINED;
564 
565 	return host;
566 }
567 
568 EXPORT_SYMBOL(mmc_alloc_host);
569 
570 /**
571  *	mmc_add_host - initialise host hardware
572  *	@host: mmc host
573  *
574  *	Register the host with the driver model. The host must be
575  *	prepared to start servicing requests before this function
576  *	completes.
577  */
578 int mmc_add_host(struct mmc_host *host)
579 {
580 	int err;
581 
582 	WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
583 		!host->ops->enable_sdio_irq);
584 
585 	err = device_add(&host->class_dev);
586 	if (err)
587 		return err;
588 
589 	led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
590 
591 #ifdef CONFIG_DEBUG_FS
592 	mmc_add_host_debugfs(host);
593 #endif
594 
595 	mmc_start_host(host);
596 	return 0;
597 }
598 
599 EXPORT_SYMBOL(mmc_add_host);
600 
601 /**
602  *	mmc_remove_host - remove host hardware
603  *	@host: mmc host
604  *
605  *	Unregister and remove all cards associated with this host,
606  *	and power down the MMC bus. No new requests will be issued
607  *	after this function has returned.
608  */
609 void mmc_remove_host(struct mmc_host *host)
610 {
611 	mmc_stop_host(host);
612 
613 #ifdef CONFIG_DEBUG_FS
614 	mmc_remove_host_debugfs(host);
615 #endif
616 
617 	device_del(&host->class_dev);
618 
619 	led_trigger_unregister_simple(host->led);
620 }
621 
622 EXPORT_SYMBOL(mmc_remove_host);
623 
624 /**
625  *	mmc_free_host - free the host structure
626  *	@host: mmc host
627  *
628  *	Free the host once all references to it have been dropped.
629  */
630 void mmc_free_host(struct mmc_host *host)
631 {
632 	mmc_pwrseq_free(host);
633 	put_device(&host->class_dev);
634 }
635 
636 EXPORT_SYMBOL(mmc_free_host);
637