drivers/usb/wusbcore/mmc.c - kernel/lockdown - Git at Google

 /*
  * WUSB Wire Adapter: Control/Data Streaming Interface (WUSB[8])
  * MMC (Microscheduled Management Command) handling
  *
  * Copyright (C) 2005-2006 Intel Corporation
  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License version
  * 2 as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  * 02110-1301, USA.
  *
  *
  * WUIEs and MMC IEs...well, they are almost the same at the end. MMC
  * IEs are Wireless USB IEs that go into the MMC period...[what is
  * that? look in Design-overview.txt].
  *
  *
  * This is a simple subsystem to keep track of which IEs are being
  * sent by the host in the MMC period.
  *
  * For each WUIE we ask to send, we keep it in an array, so we can
  * request its removal later, or replace the content. They are tracked
  * by pointer, so be sure to use the same pointer if you want to
  * remove it or update the contents.
  *
  * FIXME:
  *  - add timers that autoremove intervalled IEs?
  */
 #include <linux/usb/wusb.h>
 #include <linux/slab.h>
 #include <linux/export.h>
 #include "wusbhc.h"

 /* Initialize the MMCIEs handling mechanism */
 int wusbhc_mmcie_create(struct wusbhc *wusbhc)
 {
 	u8 mmcies = wusbhc->mmcies_max;
 	wusbhc->mmcie = kcalloc(mmcies, sizeof(wusbhc->mmcie[0]), GFP_KERNEL);
 	if (wusbhc->mmcie == NULL)
 		return -ENOMEM;
 	mutex_init(&wusbhc->mmcie_mutex);
 	return 0;
 }

 /* Release resources used by the MMCIEs handling mechanism */
 void wusbhc_mmcie_destroy(struct wusbhc *wusbhc)
 {
 	kfree(wusbhc->mmcie);
 }

 /*
  * Add or replace an MMC Wireless USB IE.
  *
  * @interval:    See WUSB1.0[8.5.3.1]
  * @repeat_cnt:  See WUSB1.0[8.5.3.1]
  * @handle:      See WUSB1.0[8.5.3.1]
  * @wuie:        Pointer to the header of the WUSB IE data to add.
  *               MUST BE allocated in a kmalloc buffer (no stack or
  *               vmalloc).
  *               THE CALLER ALWAYS OWNS THE POINTER (we don't free it
  *               on remove, we just forget about it).
  * @returns:     0 if ok, < 0 errno code on error.
  *
  * Goes over the *whole* @wusbhc->mmcie array looking for (a) the
  * first free spot and (b) if @wuie is already in the array (aka:
  * transmitted in the MMCs) the spot were it is.
  *
  * If present, we "overwrite it" (update).
  *
  *
  * NOTE: Need special ordering rules -- see below WUSB1.0 Table 7-38.
  *       The host uses the handle as the 'sort' index. We
  *       allocate the last one always for the WUIE_ID_HOST_INFO, and
  *       the rest, first come first serve in inverse order.
  *
  *       Host software must make sure that it adds the other IEs in
  *       the right order... the host hardware is responsible for
  *       placing the WCTA IEs in the right place with the other IEs
  *       set by host software.
  *
  * NOTE: we can access wusbhc->wa_descr without locking because it is
  *       read only.
  */
 int wusbhc_mmcie_set(struct wusbhc *wusbhc, u8 interval, u8 repeat_cnt,
 		     struct wuie_hdr *wuie)
 {
 	int result = -ENOBUFS;
 	unsigned handle, itr;

 	/* Search a handle, taking into account the ordering */
 	mutex_lock(&wusbhc->mmcie_mutex);
 	switch (wuie->bIEIdentifier) {
 	case WUIE_ID_HOST_INFO:
 		/* Always last */
 		handle = wusbhc->mmcies_max - 1;
 		break;
 	case WUIE_ID_ISOCH_DISCARD:
 		dev_err(wusbhc->dev, "Special ordering case for WUIE ID 0x%x "
 			"unimplemented\n", wuie->bIEIdentifier);
 		result = -ENOSYS;
 		goto error_unlock;
 	default:
 		/* search for it or find the last empty slot */
 		handle = ~0;
 		for (itr = 0; itr < wusbhc->mmcies_max - 1; itr++) {
 			if (wusbhc->mmcie[itr] == wuie) {
 				handle = itr;
 				break;
 			}
 			if (wusbhc->mmcie[itr] == NULL)
 				handle = itr;
 		}
 		if (handle == ~0)
 			goto error_unlock;
 	}
 	result = (wusbhc->mmcie_add)(wusbhc, interval, repeat_cnt, handle,
 				     wuie);
 	if (result >= 0)
 		wusbhc->mmcie[handle] = wuie;
 error_unlock:
 	mutex_unlock(&wusbhc->mmcie_mutex);
 	return result;
 }
 EXPORT_SYMBOL_GPL(wusbhc_mmcie_set);

 /*
  * Remove an MMC IE previously added with wusbhc_mmcie_set()
  *
  * @wuie	Pointer used to add the WUIE
  */
 void wusbhc_mmcie_rm(struct wusbhc *wusbhc, struct wuie_hdr *wuie)
 {
 	int result;
 	unsigned handle, itr;

 	mutex_lock(&wusbhc->mmcie_mutex);
 	for (itr = 0; itr < wusbhc->mmcies_max; itr++) {
 		if (wusbhc->mmcie[itr] == wuie) {
 			handle = itr;
 			goto found;
 		}
 	}
 	mutex_unlock(&wusbhc->mmcie_mutex);
 	return;

 found:
 	result = (wusbhc->mmcie_rm)(wusbhc, handle);
 	if (result == 0)
 		wusbhc->mmcie[itr] = NULL;
 	mutex_unlock(&wusbhc->mmcie_mutex);
 }
 EXPORT_SYMBOL_GPL(wusbhc_mmcie_rm);

 static int wusbhc_mmc_start(struct wusbhc *wusbhc)
 {
 	int ret;

 	mutex_lock(&wusbhc->mutex);
 	ret = wusbhc->start(wusbhc);
 	if (ret >= 0)
 		wusbhc->active = 1;
 	mutex_unlock(&wusbhc->mutex);

 	return ret;
 }

 static void wusbhc_mmc_stop(struct wusbhc *wusbhc)
 {
 	mutex_lock(&wusbhc->mutex);
 	wusbhc->active = 0;
 	wusbhc->stop(wusbhc, WUSB_CHANNEL_STOP_DELAY_MS);
 	mutex_unlock(&wusbhc->mutex);
 }

 /*
  * wusbhc_start - start transmitting MMCs and accepting connections
  * @wusbhc: the HC to start
  *
  * Establishes a cluster reservation, enables device connections, and
  * starts MMCs with appropriate DNTS parameters.
  */
 int wusbhc_start(struct wusbhc *wusbhc)
 {
 	int result;
 	struct device *dev = wusbhc->dev;

 	WARN_ON(wusbhc->wuie_host_info != NULL);
 	BUG_ON(wusbhc->uwb_rc == NULL);

 	result = wusbhc_rsv_establish(wusbhc);
 	if (result < 0) {
 		dev_err(dev, "cannot establish cluster reservation: %d\n",
 			result);
 		goto error_rsv_establish;
 	}

 	result = wusbhc_devconnect_start(wusbhc);
 	if (result < 0) {
 		dev_err(dev, "error enabling device connections: %d\n",
 			result);
 		goto error_devconnect_start;
 	}

 	result = wusbhc_sec_start(wusbhc);
 	if (result < 0) {
 		dev_err(dev, "error starting security in the HC: %d\n",
 			result);
 		goto error_sec_start;
 	}

 	result = wusbhc->set_num_dnts(wusbhc, wusbhc->dnts_interval,
 		wusbhc->dnts_num_slots);
 	if (result < 0) {
 		dev_err(dev, "Cannot set DNTS parameters: %d\n", result);
 		goto error_set_num_dnts;
 	}
 	result = wusbhc_mmc_start(wusbhc);
 	if (result < 0) {
 		dev_err(dev, "error starting wusbch: %d\n", result);
 		goto error_wusbhc_start;
 	}

 	return 0;

 error_wusbhc_start:
 	wusbhc_sec_stop(wusbhc);
 error_set_num_dnts:
 error_sec_start:
 	wusbhc_devconnect_stop(wusbhc);
 error_devconnect_start:
 	wusbhc_rsv_terminate(wusbhc);
 error_rsv_establish:
 	return result;
 }

 /*
  * wusbhc_stop - stop transmitting MMCs
  * @wusbhc: the HC to stop
  *
  * Stops the WUSB channel and removes the cluster reservation.
  */
 void wusbhc_stop(struct wusbhc *wusbhc)
 {
 	wusbhc_mmc_stop(wusbhc);
 	wusbhc_sec_stop(wusbhc);
 	wusbhc_devconnect_stop(wusbhc);
 	wusbhc_rsv_terminate(wusbhc);
 }

 /*
  * Set/reset/update a new CHID
  *
  * Depending on the previous state of the MMCs, start, stop or change
  * the sent MMC. This effectively switches the host controller on and
  * off (radio wise).
  */
 int wusbhc_chid_set(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid)
 {
 	int result = 0;

 	if (memcmp(chid, &wusb_ckhdid_zero, sizeof(*chid)) == 0)
 		chid = NULL;

 	mutex_lock(&wusbhc->mutex);
 	if (chid) {
 		if (wusbhc->active) {
 			mutex_unlock(&wusbhc->mutex);
 			return -EBUSY;
 		}
 		wusbhc->chid = *chid;
 	}

 	/* register with UWB if we haven't already since we are about to start
 	    the radio. */
 	if ((chid) && (wusbhc->uwb_rc == NULL)) {
 		wusbhc->uwb_rc = uwb_rc_get_by_grandpa(wusbhc->dev->parent);
 		if (wusbhc->uwb_rc == NULL) {
 			result = -ENODEV;
 			dev_err(wusbhc->dev,
 				"Cannot get associated UWB Host Controller\n");
 			goto error_rc_get;
 		}

 		result = wusbhc_pal_register(wusbhc);
 		if (result < 0) {
 			dev_err(wusbhc->dev, "Cannot register as a UWB PAL\n");
 			goto error_pal_register;
 		}
 	}
 	mutex_unlock(&wusbhc->mutex);

 	if (chid)
 		result = uwb_radio_start(&wusbhc->pal);
 	else
 		uwb_radio_stop(&wusbhc->pal);

 	return result;

 error_pal_register:
 	uwb_rc_put(wusbhc->uwb_rc);
 	wusbhc->uwb_rc = NULL;
 error_rc_get:
 	mutex_unlock(&wusbhc->mutex);

 	return result;
 }
 EXPORT_SYMBOL_GPL(wusbhc_chid_set);
	/*
	* WUSB Wire Adapter: Control/Data Streaming Interface (WUSB[8])
	* MMC (Microscheduled Management Command) handling
	*
	* Copyright (C) 2005-2006 Intel Corporation
	* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License version
	* 2 as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	* 02110-1301, USA.
	*
	*
	* WUIEs and MMC IEs...well, they are almost the same at the end. MMC
	* IEs are Wireless USB IEs that go into the MMC period...[what is
	* that? look in Design-overview.txt].
	*
	*
	* This is a simple subsystem to keep track of which IEs are being
	* sent by the host in the MMC period.
	*
	* For each WUIE we ask to send, we keep it in an array, so we can
	* request its removal later, or replace the content. They are tracked
	* by pointer, so be sure to use the same pointer if you want to
	* remove it or update the contents.
	*
	* FIXME:
	* - add timers that autoremove intervalled IEs?
	*/
	#include <linux/usb/wusb.h>
	#include <linux/slab.h>
	#include <linux/export.h>
	#include "wusbhc.h"

	/* Initialize the MMCIEs handling mechanism */
	int wusbhc_mmcie_create(struct wusbhc *wusbhc)
	{
	u8 mmcies = wusbhc->mmcies_max;
	wusbhc->mmcie = kcalloc(mmcies, sizeof(wusbhc->mmcie[0]), GFP_KERNEL);
	if (wusbhc->mmcie == NULL)
	return -ENOMEM;
	mutex_init(&wusbhc->mmcie_mutex);
	return 0;
	}

	/* Release resources used by the MMCIEs handling mechanism */
	void wusbhc_mmcie_destroy(struct wusbhc *wusbhc)
	{
	kfree(wusbhc->mmcie);
	}

	/*
	* Add or replace an MMC Wireless USB IE.
	*
	* @interval: See WUSB1.0[8.5.3.1]
	* @repeat_cnt: See WUSB1.0[8.5.3.1]
	* @handle: See WUSB1.0[8.5.3.1]
	* @wuie: Pointer to the header of the WUSB IE data to add.
	* MUST BE allocated in a kmalloc buffer (no stack or
	* vmalloc).
	* THE CALLER ALWAYS OWNS THE POINTER (we don't free it
	* on remove, we just forget about it).
	* @returns: 0 if ok, < 0 errno code on error.
	*
	* Goes over the whole @wusbhc->mmcie array looking for (a) the
	* first free spot and (b) if @wuie is already in the array (aka:
	* transmitted in the MMCs) the spot were it is.
	*
	* If present, we "overwrite it" (update).
	*
	*
	* NOTE: Need special ordering rules -- see below WUSB1.0 Table 7-38.
	* The host uses the handle as the 'sort' index. We
	* allocate the last one always for the WUIE_ID_HOST_INFO, and
	* the rest, first come first serve in inverse order.
	*
	* Host software must make sure that it adds the other IEs in
	* the right order... the host hardware is responsible for
	* placing the WCTA IEs in the right place with the other IEs
	* set by host software.
	*
	* NOTE: we can access wusbhc->wa_descr without locking because it is
	* read only.
	*/
	int wusbhc_mmcie_set(struct wusbhc *wusbhc, u8 interval, u8 repeat_cnt,
	struct wuie_hdr *wuie)
	{
	int result = -ENOBUFS;
	unsigned handle, itr;

	/* Search a handle, taking into account the ordering */
	mutex_lock(&wusbhc->mmcie_mutex);
	switch (wuie->bIEIdentifier) {
	case WUIE_ID_HOST_INFO:
	/* Always last */
	handle = wusbhc->mmcies_max - 1;
	break;
	case WUIE_ID_ISOCH_DISCARD:
	dev_err(wusbhc->dev, "Special ordering case for WUIE ID 0x%x "
	"unimplemented\n", wuie->bIEIdentifier);
	result = -ENOSYS;
	goto error_unlock;
	default:
	/* search for it or find the last empty slot */
	handle = ~0;
	for (itr = 0; itr < wusbhc->mmcies_max - 1; itr++) {
	if (wusbhc->mmcie[itr] == wuie) {
	handle = itr;
	break;
	}
	if (wusbhc->mmcie[itr] == NULL)
	handle = itr;
	}
	if (handle == ~0)
	goto error_unlock;
	}
	result = (wusbhc->mmcie_add)(wusbhc, interval, repeat_cnt, handle,
	wuie);
	if (result >= 0)
	wusbhc->mmcie[handle] = wuie;
	error_unlock:
	mutex_unlock(&wusbhc->mmcie_mutex);
	return result;
	}
	EXPORT_SYMBOL_GPL(wusbhc_mmcie_set);

	/*
	* Remove an MMC IE previously added with wusbhc_mmcie_set()
	*
	* @wuie Pointer used to add the WUIE
	*/
	void wusbhc_mmcie_rm(struct wusbhc wusbhc, struct wuie_hdr wuie)
	{
	int result;
	unsigned handle, itr;

	mutex_lock(&wusbhc->mmcie_mutex);
	for (itr = 0; itr < wusbhc->mmcies_max; itr++) {
	if (wusbhc->mmcie[itr] == wuie) {
	handle = itr;
	goto found;
	}
	}
	mutex_unlock(&wusbhc->mmcie_mutex);
	return;

	found:
	result = (wusbhc->mmcie_rm)(wusbhc, handle);
	if (result == 0)
	wusbhc->mmcie[itr] = NULL;
	mutex_unlock(&wusbhc->mmcie_mutex);
	}
	EXPORT_SYMBOL_GPL(wusbhc_mmcie_rm);

	static int wusbhc_mmc_start(struct wusbhc *wusbhc)
	{
	int ret;

	mutex_lock(&wusbhc->mutex);
	ret = wusbhc->start(wusbhc);
	if (ret >= 0)
	wusbhc->active = 1;
	mutex_unlock(&wusbhc->mutex);

	return ret;
	}

	static void wusbhc_mmc_stop(struct wusbhc *wusbhc)
	{
	mutex_lock(&wusbhc->mutex);
	wusbhc->active = 0;
	wusbhc->stop(wusbhc, WUSB_CHANNEL_STOP_DELAY_MS);
	mutex_unlock(&wusbhc->mutex);
	}

	/*
	* wusbhc_start - start transmitting MMCs and accepting connections
	* @wusbhc: the HC to start
	*
	* Establishes a cluster reservation, enables device connections, and
	* starts MMCs with appropriate DNTS parameters.
	*/
	int wusbhc_start(struct wusbhc *wusbhc)
	{
	int result;
	struct device *dev = wusbhc->dev;

	WARN_ON(wusbhc->wuie_host_info != NULL);
	BUG_ON(wusbhc->uwb_rc == NULL);

	result = wusbhc_rsv_establish(wusbhc);
	if (result < 0) {
	dev_err(dev, "cannot establish cluster reservation: %d\n",
	result);
	goto error_rsv_establish;
	}

	result = wusbhc_devconnect_start(wusbhc);
	if (result < 0) {
	dev_err(dev, "error enabling device connections: %d\n",
	result);
	goto error_devconnect_start;
	}

	result = wusbhc_sec_start(wusbhc);
	if (result < 0) {
	dev_err(dev, "error starting security in the HC: %d\n",
	result);
	goto error_sec_start;
	}

	result = wusbhc->set_num_dnts(wusbhc, wusbhc->dnts_interval,
	wusbhc->dnts_num_slots);
	if (result < 0) {
	dev_err(dev, "Cannot set DNTS parameters: %d\n", result);
	goto error_set_num_dnts;
	}
	result = wusbhc_mmc_start(wusbhc);
	if (result < 0) {
	dev_err(dev, "error starting wusbch: %d\n", result);
	goto error_wusbhc_start;
	}

	return 0;

	error_wusbhc_start:
	wusbhc_sec_stop(wusbhc);
	error_set_num_dnts:
	error_sec_start:
	wusbhc_devconnect_stop(wusbhc);
	error_devconnect_start:
	wusbhc_rsv_terminate(wusbhc);
	error_rsv_establish:
	return result;
	}

	/*
	* wusbhc_stop - stop transmitting MMCs
	* @wusbhc: the HC to stop
	*
	* Stops the WUSB channel and removes the cluster reservation.
	*/
	void wusbhc_stop(struct wusbhc *wusbhc)
	{
	wusbhc_mmc_stop(wusbhc);
	wusbhc_sec_stop(wusbhc);
	wusbhc_devconnect_stop(wusbhc);
	wusbhc_rsv_terminate(wusbhc);
	}

	/*
	* Set/reset/update a new CHID
	*
	* Depending on the previous state of the MMCs, start, stop or change
	* the sent MMC. This effectively switches the host controller on and
	* off (radio wise).
	*/
	int wusbhc_chid_set(struct wusbhc wusbhc, const struct wusb_ckhdid chid)
	{
	int result = 0;

	if (memcmp(chid, &wusb_ckhdid_zero, sizeof(*chid)) == 0)
	chid = NULL;

	mutex_lock(&wusbhc->mutex);
	if (chid) {
	if (wusbhc->active) {
	mutex_unlock(&wusbhc->mutex);
	return -EBUSY;
	}
	wusbhc->chid = *chid;
	}

	/* register with UWB if we haven't already since we are about to start
	the radio. */
	if ((chid) && (wusbhc->uwb_rc == NULL)) {
	wusbhc->uwb_rc = uwb_rc_get_by_grandpa(wusbhc->dev->parent);
	if (wusbhc->uwb_rc == NULL) {
	result = -ENODEV;
	dev_err(wusbhc->dev,
	"Cannot get associated UWB Host Controller\n");
	goto error_rc_get;
	}

	result = wusbhc_pal_register(wusbhc);
	if (result < 0) {
	dev_err(wusbhc->dev, "Cannot register as a UWB PAL\n");
	goto error_pal_register;
	}
	}
	mutex_unlock(&wusbhc->mutex);

	if (chid)
	result = uwb_radio_start(&wusbhc->pal);
	else
	uwb_radio_stop(&wusbhc->pal);

	return result;

	error_pal_register:
	uwb_rc_put(wusbhc->uwb_rc);
	wusbhc->uwb_rc = NULL;
	error_rc_get:
	mutex_unlock(&wusbhc->mutex);

	return result;
	}
	EXPORT_SYMBOL_GPL(wusbhc_chid_set);