Revision 87b87a3fc0eec58d95e4216392f889a26439ad22 authored by Daniel Drake on 09 April 2012, 23:14:20 UTC, committed by Chris Ball on 21 April 2012, 00:44:25 UTC
Commit c79396c191bc19 ("mmc: sdhci: prevent card detection activity
for non-removable cards") disables card detection where the cards
are marked as non-removable.

This makes sense, but the implementation detail of calling
mmc_card_is_removable() causes some problems, because
mmc_card_is_removable() is overloaded with CONFIG_MMC_UNSAFE_RESUME
semantics.

In the OLPC XO case, we need CONFIG_MMC_UNSAFE_RESUME because our root
filesystem is stored on SD, but we also have external SD card slots
where we want automatic card detection.

Refine the check to only apply to hosts marked as MMC_CAP_NONREMOVABLE,
which is defined to mean that the card is *really* nonremovable. This
could be revisited in future if we find a way to improve
CONFIG_MMC_UNSAFE_RESUME semantics.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Acked-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
[stable@: please apply to 3.3-stable]
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
1 parent a99aa9b
Raw File
card.c
/*
 * card.c - contains functions for managing groups of PnP devices
 *
 * Copyright 2002 Adam Belay <ambx1@neo.rr.com>
 */

#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/slab.h>
#include <linux/pnp.h>
#include <linux/dma-mapping.h>
#include "base.h"

LIST_HEAD(pnp_cards);
static LIST_HEAD(pnp_card_drivers);

static const struct pnp_card_device_id *match_card(struct pnp_card_driver *drv,
						   struct pnp_card *card)
{
	const struct pnp_card_device_id *drv_id = drv->id_table;

	while (*drv_id->id) {
		if (compare_pnp_id(card->id, drv_id->id)) {
			int i = 0;

			for (;;) {
				int found;
				struct pnp_dev *dev;

				if (i == PNP_MAX_DEVICES ||
				    !*drv_id->devs[i].id)
					return drv_id;
				found = 0;
				card_for_each_dev(card, dev) {
					if (compare_pnp_id(dev->id,
						   drv_id->devs[i].id)) {
						found = 1;
						break;
					}
				}
				if (!found)
					break;
				i++;
			}
		}
		drv_id++;
	}
	return NULL;
}

static void card_remove(struct pnp_dev *dev)
{
	dev->card_link = NULL;
}

static void card_remove_first(struct pnp_dev *dev)
{
	struct pnp_card_driver *drv = to_pnp_card_driver(dev->driver);

	if (!dev->card || !drv)
		return;
	if (drv->remove)
		drv->remove(dev->card_link);
	drv->link.remove = &card_remove;
	kfree(dev->card_link);
	card_remove(dev);
}

static int card_probe(struct pnp_card *card, struct pnp_card_driver *drv)
{
	const struct pnp_card_device_id *id;
	struct pnp_card_link *clink;
	struct pnp_dev *dev;

	if (!drv->probe)
		return 0;
	id = match_card(drv, card);
	if (!id)
		return 0;

	clink = pnp_alloc(sizeof(*clink));
	if (!clink)
		return 0;
	clink->card = card;
	clink->driver = drv;
	clink->pm_state = PMSG_ON;

	if (drv->probe(clink, id) >= 0)
		return 1;

	/* Recovery */
	card_for_each_dev(card, dev) {
		if (dev->card_link == clink)
			pnp_release_card_device(dev);
	}
	kfree(clink);
	return 0;
}

/**
 * pnp_add_card_id - adds an EISA id to the specified card
 * @id: pointer to a pnp_id structure
 * @card: pointer to the desired card
 */
static struct pnp_id *pnp_add_card_id(struct pnp_card *card, char *id)
{
	struct pnp_id *dev_id, *ptr;

	dev_id = kzalloc(sizeof(struct pnp_id), GFP_KERNEL);
	if (!dev_id)
		return NULL;

	dev_id->id[0] = id[0];
	dev_id->id[1] = id[1];
	dev_id->id[2] = id[2];
	dev_id->id[3] = tolower(id[3]);
	dev_id->id[4] = tolower(id[4]);
	dev_id->id[5] = tolower(id[5]);
	dev_id->id[6] = tolower(id[6]);
	dev_id->id[7] = '\0';

	dev_id->next = NULL;
	ptr = card->id;
	while (ptr && ptr->next)
		ptr = ptr->next;
	if (ptr)
		ptr->next = dev_id;
	else
		card->id = dev_id;

	return dev_id;
}

static void pnp_free_card_ids(struct pnp_card *card)
{
	struct pnp_id *id;
	struct pnp_id *next;

	id = card->id;
	while (id) {
		next = id->next;
		kfree(id);
		id = next;
	}
}

static void pnp_release_card(struct device *dmdev)
{
	struct pnp_card *card = to_pnp_card(dmdev);

	pnp_free_card_ids(card);
	kfree(card);
}

struct pnp_card *pnp_alloc_card(struct pnp_protocol *protocol, int id, char *pnpid)
{
	struct pnp_card *card;
	struct pnp_id *dev_id;

	card = kzalloc(sizeof(struct pnp_card), GFP_KERNEL);
	if (!card)
		return NULL;

	card->protocol = protocol;
	card->number = id;

	card->dev.parent = &card->protocol->dev;
	dev_set_name(&card->dev, "%02x:%02x", card->protocol->number, card->number);

	card->dev.coherent_dma_mask = DMA_BIT_MASK(24);
	card->dev.dma_mask = &card->dev.coherent_dma_mask;

	dev_id = pnp_add_card_id(card, pnpid);
	if (!dev_id) {
		kfree(card);
		return NULL;
	}

	return card;
}

static ssize_t pnp_show_card_name(struct device *dmdev,
				  struct device_attribute *attr, char *buf)
{
	char *str = buf;
	struct pnp_card *card = to_pnp_card(dmdev);

	str += sprintf(str, "%s\n", card->name);
	return (str - buf);
}

static DEVICE_ATTR(name, S_IRUGO, pnp_show_card_name, NULL);

static ssize_t pnp_show_card_ids(struct device *dmdev,
				 struct device_attribute *attr, char *buf)
{
	char *str = buf;
	struct pnp_card *card = to_pnp_card(dmdev);
	struct pnp_id *pos = card->id;

	while (pos) {
		str += sprintf(str, "%s\n", pos->id);
		pos = pos->next;
	}
	return (str - buf);
}

static DEVICE_ATTR(card_id, S_IRUGO, pnp_show_card_ids, NULL);

static int pnp_interface_attach_card(struct pnp_card *card)
{
	int rc = device_create_file(&card->dev, &dev_attr_name);

	if (rc)
		return rc;

	rc = device_create_file(&card->dev, &dev_attr_card_id);
	if (rc)
		goto err_name;

	return 0;

err_name:
	device_remove_file(&card->dev, &dev_attr_name);
	return rc;
}

/**
 * pnp_add_card - adds a PnP card to the PnP Layer
 * @card: pointer to the card to add
 */
int pnp_add_card(struct pnp_card *card)
{
	int error;
	struct list_head *pos, *temp;

	card->dev.bus = NULL;
	card->dev.release = &pnp_release_card;
	error = device_register(&card->dev);
	if (error) {
		dev_err(&card->dev, "could not register (err=%d)\n", error);
		return error;
	}

	pnp_interface_attach_card(card);
	spin_lock(&pnp_lock);
	list_add_tail(&card->global_list, &pnp_cards);
	list_add_tail(&card->protocol_list, &card->protocol->cards);
	spin_unlock(&pnp_lock);

	/* we wait until now to add devices in order to ensure the drivers
	 * will be able to use all of the related devices on the card
	 * without waiting an unreasonable length of time */
	list_for_each(pos, &card->devices) {
		struct pnp_dev *dev = card_to_pnp_dev(pos);
		__pnp_add_device(dev);
	}

	/* match with card drivers */
	list_for_each_safe(pos, temp, &pnp_card_drivers) {
		struct pnp_card_driver *drv =
		    list_entry(pos, struct pnp_card_driver,
			       global_list);
		card_probe(card, drv);
	}
	return 0;
}

/**
 * pnp_remove_card - removes a PnP card from the PnP Layer
 * @card: pointer to the card to remove
 */
void pnp_remove_card(struct pnp_card *card)
{
	struct list_head *pos, *temp;

	device_unregister(&card->dev);
	spin_lock(&pnp_lock);
	list_del(&card->global_list);
	list_del(&card->protocol_list);
	spin_unlock(&pnp_lock);
	list_for_each_safe(pos, temp, &card->devices) {
		struct pnp_dev *dev = card_to_pnp_dev(pos);
		pnp_remove_card_device(dev);
	}
}

/**
 * pnp_add_card_device - adds a device to the specified card
 * @card: pointer to the card to add to
 * @dev: pointer to the device to add
 */
int pnp_add_card_device(struct pnp_card *card, struct pnp_dev *dev)
{
	dev->dev.parent = &card->dev;
	dev->card_link = NULL;
	dev_set_name(&dev->dev, "%02x:%02x.%02x",
		     dev->protocol->number, card->number, dev->number);
	spin_lock(&pnp_lock);
	dev->card = card;
	list_add_tail(&dev->card_list, &card->devices);
	spin_unlock(&pnp_lock);
	return 0;
}

/**
 * pnp_remove_card_device- removes a device from the specified card
 * @dev: pointer to the device to remove
 */
void pnp_remove_card_device(struct pnp_dev *dev)
{
	spin_lock(&pnp_lock);
	dev->card = NULL;
	list_del(&dev->card_list);
	spin_unlock(&pnp_lock);
	__pnp_remove_device(dev);
}

/**
 * pnp_request_card_device - Searches for a PnP device under the specified card
 * @clink: pointer to the card link, cannot be NULL
 * @id: pointer to a PnP ID structure that explains the rules for finding the device
 * @from: Starting place to search from. If NULL it will start from the beginning.
 */
struct pnp_dev *pnp_request_card_device(struct pnp_card_link *clink,
					const char *id, struct pnp_dev *from)
{
	struct list_head *pos;
	struct pnp_dev *dev;
	struct pnp_card_driver *drv;
	struct pnp_card *card;

	if (!clink || !id)
		return NULL;

	card = clink->card;
	drv = clink->driver;
	if (!from) {
		pos = card->devices.next;
	} else {
		if (from->card != card)
			return NULL;
		pos = from->card_list.next;
	}
	while (pos != &card->devices) {
		dev = card_to_pnp_dev(pos);
		if ((!dev->card_link) && compare_pnp_id(dev->id, id))
			goto found;
		pos = pos->next;
	}

	return NULL;

found:
	dev->card_link = clink;
	dev->dev.driver = &drv->link.driver;
	if (pnp_bus_type.probe(&dev->dev))
		goto err_out;
	if (device_bind_driver(&dev->dev))
		goto err_out;

	return dev;

err_out:
	dev->dev.driver = NULL;
	dev->card_link = NULL;
	return NULL;
}

/**
 * pnp_release_card_device - call this when the driver no longer needs the device
 * @dev: pointer to the PnP device structure
 */
void pnp_release_card_device(struct pnp_dev *dev)
{
	struct pnp_card_driver *drv = dev->card_link->driver;

	drv->link.remove = &card_remove;
	device_release_driver(&dev->dev);
	drv->link.remove = &card_remove_first;
}

/*
 * suspend/resume callbacks
 */
static int card_suspend(struct pnp_dev *dev, pm_message_t state)
{
	struct pnp_card_link *link = dev->card_link;

	if (link->pm_state.event == state.event)
		return 0;
	link->pm_state = state;
	return link->driver->suspend(link, state);
}

static int card_resume(struct pnp_dev *dev)
{
	struct pnp_card_link *link = dev->card_link;

	if (link->pm_state.event == PM_EVENT_ON)
		return 0;
	link->pm_state = PMSG_ON;
	link->driver->resume(link);
	return 0;
}

/**
 * pnp_register_card_driver - registers a PnP card driver with the PnP Layer
 * @drv: pointer to the driver to register
 */
int pnp_register_card_driver(struct pnp_card_driver *drv)
{
	int error;
	struct list_head *pos, *temp;

	drv->link.name = drv->name;
	drv->link.id_table = NULL;	/* this will disable auto matching */
	drv->link.flags = drv->flags;
	drv->link.probe = NULL;
	drv->link.remove = &card_remove_first;
	drv->link.suspend = drv->suspend ? card_suspend : NULL;
	drv->link.resume = drv->resume ? card_resume : NULL;

	error = pnp_register_driver(&drv->link);
	if (error < 0)
		return error;

	spin_lock(&pnp_lock);
	list_add_tail(&drv->global_list, &pnp_card_drivers);
	spin_unlock(&pnp_lock);

	list_for_each_safe(pos, temp, &pnp_cards) {
		struct pnp_card *card =
		    list_entry(pos, struct pnp_card, global_list);
		card_probe(card, drv);
	}
	return 0;
}

/**
 * pnp_unregister_card_driver - unregisters a PnP card driver from the PnP Layer
 * @drv: pointer to the driver to unregister
 */
void pnp_unregister_card_driver(struct pnp_card_driver *drv)
{
	spin_lock(&pnp_lock);
	list_del(&drv->global_list);
	spin_unlock(&pnp_lock);
	pnp_unregister_driver(&drv->link);
}

EXPORT_SYMBOL(pnp_request_card_device);
EXPORT_SYMBOL(pnp_release_card_device);
EXPORT_SYMBOL(pnp_register_card_driver);
EXPORT_SYMBOL(pnp_unregister_card_driver);
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