diff options
Diffstat (limited to 'drivers/iommu/iommu.c')
-rw-r--r-- | drivers/iommu/iommu.c | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c new file mode 100644 index 0000000..2198b2d --- /dev/null +++ b/drivers/iommu/iommu.c @@ -0,0 +1,343 @@ +/* + * 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); |