drivers/iommu/iommu.c - kernel/windcharger - Git at Google

 /*
  * Copyright (C) 2007-2008 Advanced Micro Devices, Inc.
  * Author: Joerg Roedel <joerg.roedel@amd.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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */

 #define pr_fmt(fmt)    "%s: " fmt, __func__

 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/bug.h>
 #include <linux/types.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/errno.h>
 #include <linux/iommu.h>

 static ssize_t show_iommu_group(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	unsigned int groupid;

 	if (iommu_device_group(dev, &groupid))
 		return 0;

 	return sprintf(buf, "%u", groupid);
 }
 static DEVICE_ATTR(iommu_group, S_IRUGO, show_iommu_group, NULL);

 static int add_iommu_group(struct device *dev, void *data)
 {
 	unsigned int groupid;

 	if (iommu_device_group(dev, &groupid) == 0)
 		return device_create_file(dev, &dev_attr_iommu_group);

 	return 0;
 }

 static int remove_iommu_group(struct device *dev)
 {
 	unsigned int groupid;

 	if (iommu_device_group(dev, &groupid) == 0)
 		device_remove_file(dev, &dev_attr_iommu_group);

 	return 0;
 }

 static int iommu_device_notifier(struct notifier_block *nb,
 				 unsigned long action, void *data)
 {
 	struct device *dev = data;

 	if (action == BUS_NOTIFY_ADD_DEVICE)
 		return add_iommu_group(dev, NULL);
 	else if (action == BUS_NOTIFY_DEL_DEVICE)
 		return remove_iommu_group(dev);

 	return 0;
 }

 static struct notifier_block iommu_device_nb = {
 	.notifier_call = iommu_device_notifier,
 };

 static void iommu_bus_init(struct bus_type *bus, struct iommu_ops *ops)
 {
 	bus_register_notifier(bus, &iommu_device_nb);
 	bus_for_each_dev(bus, NULL, NULL, add_iommu_group);
 }

 /**
  * bus_set_iommu - set iommu-callbacks for the bus
  * @bus: bus.
  * @ops: the callbacks provided by the iommu-driver
  *
  * This function is called by an iommu driver to set the iommu methods
  * used for a particular bus. Drivers for devices on that bus can use
  * the iommu-api after these ops are registered.
  * This special function is needed because IOMMUs are usually devices on
  * the bus itself, so the iommu drivers are not initialized when the bus
  * is set up. With this function the iommu-driver can set the iommu-ops
  * afterwards.
  */
 int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops)
 {
 	if (bus->iommu_ops != NULL)
 		return -EBUSY;

 	bus->iommu_ops = ops;

 	/* Do IOMMU specific setup for this bus-type */
 	iommu_bus_init(bus, ops);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(bus_set_iommu);

 bool iommu_present(struct bus_type *bus)
 {
 	return bus->iommu_ops != NULL;
 }
 EXPORT_SYMBOL_GPL(iommu_present);

 /**
  * iommu_set_fault_handler() - set a fault handler for an iommu domain
  * @domain: iommu domain
  * @handler: fault handler
  *
  * This function should be used by IOMMU users which want to be notified
  * whenever an IOMMU fault happens.
  *
  * The fault handler itself should return 0 on success, and an appropriate
  * error code otherwise.
  */
 void iommu_set_fault_handler(struct iommu_domain *domain,
 					iommu_fault_handler_t handler)
 {
 	BUG_ON(!domain);

 	domain->handler = handler;
 }
 EXPORT_SYMBOL_GPL(iommu_set_fault_handler);

 struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
 {
 	struct iommu_domain *domain;
 	int ret;

 	if (bus == NULL || bus->iommu_ops == NULL)
 		return NULL;

 	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 	if (!domain)
 		return NULL;

 	domain->ops = bus->iommu_ops;

 	ret = domain->ops->domain_init(domain);
 	if (ret)
 		goto out_free;

 	return domain;

 out_free:
 	kfree(domain);

 	return NULL;
 }
 EXPORT_SYMBOL_GPL(iommu_domain_alloc);

 void iommu_domain_free(struct iommu_domain *domain)
 {
 	if (likely(domain->ops->domain_destroy != NULL))
 		domain->ops->domain_destroy(domain);

 	kfree(domain);
 }
 EXPORT_SYMBOL_GPL(iommu_domain_free);

 int iommu_attach_device(struct iommu_domain *domain, struct device *dev)
 {
 	if (unlikely(domain->ops->attach_dev == NULL))
 		return -ENODEV;

 	return domain->ops->attach_dev(domain, dev);
 }
 EXPORT_SYMBOL_GPL(iommu_attach_device);

 void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
 {
 	if (unlikely(domain->ops->detach_dev == NULL))
 		return;

 	domain->ops->detach_dev(domain, dev);
 }
 EXPORT_SYMBOL_GPL(iommu_detach_device);

 phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
 			       unsigned long iova)
 {
 	if (unlikely(domain->ops->iova_to_phys == NULL))
 		return 0;

 	return domain->ops->iova_to_phys(domain, iova);
 }
 EXPORT_SYMBOL_GPL(iommu_iova_to_phys);

 int iommu_domain_has_cap(struct iommu_domain *domain,
 			 unsigned long cap)
 {
 	if (unlikely(domain->ops->domain_has_cap == NULL))
 		return 0;

 	return domain->ops->domain_has_cap(domain, cap);
 }
 EXPORT_SYMBOL_GPL(iommu_domain_has_cap);

 int iommu_map(struct iommu_domain *domain, unsigned long iova,
 	      phys_addr_t paddr, size_t size, int prot)
 {
 	unsigned long orig_iova = iova;
 	unsigned int min_pagesz;
 	size_t orig_size = size;
 	int ret = 0;

 	if (unlikely(domain->ops->map == NULL))
 		return -ENODEV;

 	/* find out the minimum page size supported */
 	min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap);

 	/*
 	 * both the virtual address and the physical one, as well as
 	 * the size of the mapping, must be aligned (at least) to the
 	 * size of the smallest page supported by the hardware
 	 */
 	if (!IS_ALIGNED(iova | paddr | size, min_pagesz)) {
 		pr_err("unaligned: iova 0x%lx pa 0x%lx size 0x%lx min_pagesz "
 			"0x%x\n", iova, (unsigned long)paddr,
 			(unsigned long)size, min_pagesz);
 		return -EINVAL;
 	}

 	pr_debug("map: iova 0x%lx pa 0x%lx size 0x%lx\n", iova,
 				(unsigned long)paddr, (unsigned long)size);

 	while (size) {
 		unsigned long pgsize, addr_merge = iova | paddr;
 		unsigned int pgsize_idx;

 		/* Max page size that still fits into 'size' */
 		pgsize_idx = __fls(size);

 		/* need to consider alignment requirements ? */
 		if (likely(addr_merge)) {
 			/* Max page size allowed by both iova and paddr */
 			unsigned int align_pgsize_idx = __ffs(addr_merge);

 			pgsize_idx = min(pgsize_idx, align_pgsize_idx);
 		}

 		/* build a mask of acceptable page sizes */
 		pgsize = (1UL << (pgsize_idx + 1)) - 1;

 		/* throw away page sizes not supported by the hardware */
 		pgsize &= domain->ops->pgsize_bitmap;

 		/* make sure we're still sane */
 		BUG_ON(!pgsize);

 		/* pick the biggest page */
 		pgsize_idx = __fls(pgsize);
 		pgsize = 1UL << pgsize_idx;

 		pr_debug("mapping: iova 0x%lx pa 0x%lx pgsize %lu\n", iova,
 					(unsigned long)paddr, pgsize);

 		ret = domain->ops->map(domain, iova, paddr, pgsize, prot);
 		if (ret)
 			break;

 		iova += pgsize;
 		paddr += pgsize;
 		size -= pgsize;
 	}

 	/* unroll mapping in case something went wrong */
 	if (ret)
 		iommu_unmap(domain, orig_iova, orig_size - size);

 	return ret;
 }
 EXPORT_SYMBOL_GPL(iommu_map);

 size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size)
 {
 	size_t unmapped_page, unmapped = 0;
 	unsigned int min_pagesz;

 	if (unlikely(domain->ops->unmap == NULL))
 		return -ENODEV;

 	/* find out the minimum page size supported */
 	min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap);

 	/*
 	 * The virtual address, as well as the size of the mapping, must be
 	 * aligned (at least) to the size of the smallest page supported
 	 * by the hardware
 	 */
 	if (!IS_ALIGNED(iova | size, min_pagesz)) {
 		pr_err("unaligned: iova 0x%lx size 0x%lx min_pagesz 0x%x\n",
 					iova, (unsigned long)size, min_pagesz);
 		return -EINVAL;
 	}

 	pr_debug("unmap this: iova 0x%lx size 0x%lx\n", iova,
 							(unsigned long)size);

 	/*
 	 * Keep iterating until we either unmap 'size' bytes (or more)
 	 * or we hit an area that isn't mapped.
 	 */
 	while (unmapped < size) {
 		size_t left = size - unmapped;

 		unmapped_page = domain->ops->unmap(domain, iova, left);
 		if (!unmapped_page)
 			break;

 		pr_debug("unmapped: iova 0x%lx size %lx\n", iova,
 					(unsigned long)unmapped_page);

 		iova += unmapped_page;
 		unmapped += unmapped_page;
 	}

 	return unmapped;
 }
 EXPORT_SYMBOL_GPL(iommu_unmap);

 int iommu_device_group(struct device *dev, unsigned int *groupid)
 {
 	if (iommu_present(dev->bus) && dev->bus->iommu_ops->device_group)
 		return dev->bus->iommu_ops->device_group(dev, groupid);

 	return -ENODEV;
 }
 EXPORT_SYMBOL_GPL(iommu_device_group);
	/*
	* Copyright (C) 2007-2008 Advanced Micro Devices, Inc.
	* Author: Joerg Roedel <joerg.roedel@amd.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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#define pr_fmt(fmt) "%s: " fmt, __func__

	#include <linux/device.h>
	#include <linux/kernel.h>
	#include <linux/bug.h>
	#include <linux/types.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/errno.h>
	#include <linux/iommu.h>

	static ssize_t show_iommu_group(struct device *dev,
	struct device_attribute attr, char buf)
	{
	unsigned int groupid;

	if (iommu_device_group(dev, &groupid))
	return 0;

	return sprintf(buf, "%u", groupid);
	}
	static DEVICE_ATTR(iommu_group, S_IRUGO, show_iommu_group, NULL);

	static int add_iommu_group(struct device dev, void data)
	{
	unsigned int groupid;

	if (iommu_device_group(dev, &groupid) == 0)
	return device_create_file(dev, &dev_attr_iommu_group);

	return 0;
	}

	static int remove_iommu_group(struct device *dev)
	{
	unsigned int groupid;

	if (iommu_device_group(dev, &groupid) == 0)
	device_remove_file(dev, &dev_attr_iommu_group);

	return 0;
	}

	static int iommu_device_notifier(struct notifier_block *nb,
	unsigned long action, void *data)
	{
	struct device *dev = data;

	if (action == BUS_NOTIFY_ADD_DEVICE)
	return add_iommu_group(dev, NULL);
	else if (action == BUS_NOTIFY_DEL_DEVICE)
	return remove_iommu_group(dev);

	return 0;
	}

	static struct notifier_block iommu_device_nb = {
	.notifier_call = iommu_device_notifier,
	};

	static void iommu_bus_init(struct bus_type bus, struct iommu_ops ops)
	{
	bus_register_notifier(bus, &iommu_device_nb);
	bus_for_each_dev(bus, NULL, NULL, add_iommu_group);
	}

	/**
	* bus_set_iommu - set iommu-callbacks for the bus
	* @bus: bus.
	* @ops: the callbacks provided by the iommu-driver
	*
	* This function is called by an iommu driver to set the iommu methods
	* used for a particular bus. Drivers for devices on that bus can use
	* the iommu-api after these ops are registered.
	* This special function is needed because IOMMUs are usually devices on
	* the bus itself, so the iommu drivers are not initialized when the bus
	* is set up. With this function the iommu-driver can set the iommu-ops
	* afterwards.
	*/
	int bus_set_iommu(struct bus_type bus, struct iommu_ops ops)
	{
	if (bus->iommu_ops != NULL)
	return -EBUSY;

	bus->iommu_ops = ops;

	/* Do IOMMU specific setup for this bus-type */
	iommu_bus_init(bus, ops);

	return 0;
	}
	EXPORT_SYMBOL_GPL(bus_set_iommu);

	bool iommu_present(struct bus_type *bus)
	{
	return bus->iommu_ops != NULL;
	}
	EXPORT_SYMBOL_GPL(iommu_present);

	/**
	* iommu_set_fault_handler() - set a fault handler for an iommu domain
	* @domain: iommu domain
	* @handler: fault handler
	*
	* This function should be used by IOMMU users which want to be notified
	* whenever an IOMMU fault happens.
	*
	* The fault handler itself should return 0 on success, and an appropriate
	* error code otherwise.
	*/
	void iommu_set_fault_handler(struct iommu_domain *domain,
	iommu_fault_handler_t handler)
	{
	BUG_ON(!domain);

	domain->handler = handler;
	}
	EXPORT_SYMBOL_GPL(iommu_set_fault_handler);

	struct iommu_domain iommu_domain_alloc(struct bus_type bus)
	{
	struct iommu_domain *domain;
	int ret;

	if (bus == NULL \|\| bus->iommu_ops == NULL)
	return NULL;

	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
	if (!domain)
	return NULL;

	domain->ops = bus->iommu_ops;

	ret = domain->ops->domain_init(domain);
	if (ret)
	goto out_free;

	return domain;

	out_free:
	kfree(domain);

	return NULL;
	}
	EXPORT_SYMBOL_GPL(iommu_domain_alloc);

	void iommu_domain_free(struct iommu_domain *domain)
	{
	if (likely(domain->ops->domain_destroy != NULL))
	domain->ops->domain_destroy(domain);

	kfree(domain);
	}
	EXPORT_SYMBOL_GPL(iommu_domain_free);

	int iommu_attach_device(struct iommu_domain domain, struct device dev)
	{
	if (unlikely(domain->ops->attach_dev == NULL))
	return -ENODEV;

	return domain->ops->attach_dev(domain, dev);
	}
	EXPORT_SYMBOL_GPL(iommu_attach_device);

	void iommu_detach_device(struct iommu_domain domain, struct device dev)
	{
	if (unlikely(domain->ops->detach_dev == NULL))
	return;

	domain->ops->detach_dev(domain, dev);
	}
	EXPORT_SYMBOL_GPL(iommu_detach_device);

	phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
	unsigned long iova)
	{
	if (unlikely(domain->ops->iova_to_phys == NULL))
	return 0;

	return domain->ops->iova_to_phys(domain, iova);
	}
	EXPORT_SYMBOL_GPL(iommu_iova_to_phys);

	int iommu_domain_has_cap(struct iommu_domain *domain,
	unsigned long cap)
	{
	if (unlikely(domain->ops->domain_has_cap == NULL))
	return 0;

	return domain->ops->domain_has_cap(domain, cap);
	}
	EXPORT_SYMBOL_GPL(iommu_domain_has_cap);

	int iommu_map(struct iommu_domain *domain, unsigned long iova,
	phys_addr_t paddr, size_t size, int prot)
	{
	unsigned long orig_iova = iova;
	unsigned int min_pagesz;
	size_t orig_size = size;
	int ret = 0;

	if (unlikely(domain->ops->map == NULL))
	return -ENODEV;

	/* find out the minimum page size supported */
	min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap);

	/*
	* both the virtual address and the physical one, as well as
	* the size of the mapping, must be aligned (at least) to the
	* size of the smallest page supported by the hardware
	*/
	if (!IS_ALIGNED(iova \| paddr \| size, min_pagesz)) {
	pr_err("unaligned: iova 0x%lx pa 0x%lx size 0x%lx min_pagesz "
	"0x%x\n", iova, (unsigned long)paddr,
	(unsigned long)size, min_pagesz);
	return -EINVAL;
	}

	pr_debug("map: iova 0x%lx pa 0x%lx size 0x%lx\n", iova,
	(unsigned long)paddr, (unsigned long)size);

	while (size) {
	unsigned long pgsize, addr_merge = iova \| paddr;
	unsigned int pgsize_idx;

	/* Max page size that still fits into 'size' */
	pgsize_idx = __fls(size);

	/* need to consider alignment requirements ? */
	if (likely(addr_merge)) {
	/* Max page size allowed by both iova and paddr */
	unsigned int align_pgsize_idx = __ffs(addr_merge);

	pgsize_idx = min(pgsize_idx, align_pgsize_idx);
	}

	/* build a mask of acceptable page sizes */
	pgsize = (1UL << (pgsize_idx + 1)) - 1;

	/* throw away page sizes not supported by the hardware */
	pgsize &= domain->ops->pgsize_bitmap;

	/* make sure we're still sane */
	BUG_ON(!pgsize);

	/* pick the biggest page */
	pgsize_idx = __fls(pgsize);
	pgsize = 1UL << pgsize_idx;

	pr_debug("mapping: iova 0x%lx pa 0x%lx pgsize %lu\n", iova,
	(unsigned long)paddr, pgsize);

	ret = domain->ops->map(domain, iova, paddr, pgsize, prot);
	if (ret)
	break;

	iova += pgsize;
	paddr += pgsize;
	size -= pgsize;
	}

	/* unroll mapping in case something went wrong */
	if (ret)
	iommu_unmap(domain, orig_iova, orig_size - size);

	return ret;
	}
	EXPORT_SYMBOL_GPL(iommu_map);

	size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size)
	{
	size_t unmapped_page, unmapped = 0;
	unsigned int min_pagesz;

	if (unlikely(domain->ops->unmap == NULL))
	return -ENODEV;

	/* find out the minimum page size supported */
	min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap);

	/*
	* The virtual address, as well as the size of the mapping, must be
	* aligned (at least) to the size of the smallest page supported
	* by the hardware
	*/
	if (!IS_ALIGNED(iova \| size, min_pagesz)) {
	pr_err("unaligned: iova 0x%lx size 0x%lx min_pagesz 0x%x\n",
	iova, (unsigned long)size, min_pagesz);
	return -EINVAL;
	}

	pr_debug("unmap this: iova 0x%lx size 0x%lx\n", iova,
	(unsigned long)size);

	/*
	* Keep iterating until we either unmap 'size' bytes (or more)
	* or we hit an area that isn't mapped.
	*/
	while (unmapped < size) {
	size_t left = size - unmapped;

	unmapped_page = domain->ops->unmap(domain, iova, left);
	if (!unmapped_page)
	break;

	pr_debug("unmapped: iova 0x%lx size %lx\n", iova,
	(unsigned long)unmapped_page);

	iova += unmapped_page;
	unmapped += unmapped_page;
	}

	return unmapped;
	}
	EXPORT_SYMBOL_GPL(iommu_unmap);

	int iommu_device_group(struct device dev, unsigned int groupid)
	{
	if (iommu_present(dev->bus) && dev->bus->iommu_ops->device_group)
	return dev->bus->iommu_ops->device_group(dev, groupid);

	return -ENODEV;
	}
	EXPORT_SYMBOL_GPL(iommu_device_group);