diff options
| -rw-r--r-- | drivers/iommu/dma-iommu.c | 119 | ||||
| -rw-r--r-- | include/linux/dma-iommu.h | 6 |
2 files changed, 102 insertions, 23 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 2db0d641cf45..de41ead6542a 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -37,15 +37,50 @@ struct iommu_dma_msi_page { phys_addr_t phys; }; +enum iommu_dma_cookie_type { + IOMMU_DMA_IOVA_COOKIE, + IOMMU_DMA_MSI_COOKIE, +}; + struct iommu_dma_cookie { - struct iova_domain iovad; - struct list_head msi_page_list; - spinlock_t msi_lock; + enum iommu_dma_cookie_type type; + union { + /* Full allocator for IOMMU_DMA_IOVA_COOKIE */ + struct iova_domain iovad; + /* Trivial linear page allocator for IOMMU_DMA_MSI_COOKIE */ + dma_addr_t msi_iova; + }; + struct list_head msi_page_list; + spinlock_t msi_lock; }; +static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie) +{ + if (cookie->type == IOMMU_DMA_IOVA_COOKIE) + return cookie->iovad.granule; + return PAGE_SIZE; +} + static inline struct iova_domain *cookie_iovad(struct iommu_domain *domain) { - return &((struct iommu_dma_cookie *)domain->iova_cookie)->iovad; + struct iommu_dma_cookie *cookie = domain->iova_cookie; + + if (cookie->type == IOMMU_DMA_IOVA_COOKIE) + return &cookie->iovad; + return NULL; +} + +static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type) +{ + struct iommu_dma_cookie *cookie; + + cookie = kzalloc(sizeof(*cookie), GFP_KERNEL); + if (cookie) { + spin_lock_init(&cookie->msi_lock); + INIT_LIST_HEAD(&cookie->msi_page_list); + cookie->type = type; + } + return cookie; } int iommu_dma_init(void) @@ -62,25 +97,53 @@ int iommu_dma_init(void) */ int iommu_get_dma_cookie(struct iommu_domain *domain) { + if (domain->iova_cookie) + return -EEXIST; + + domain->iova_cookie = cookie_alloc(IOMMU_DMA_IOVA_COOKIE); + if (!domain->iova_cookie) + return -ENOMEM; + + return 0; +} +EXPORT_SYMBOL(iommu_get_dma_cookie); + +/** + * iommu_get_msi_cookie - Acquire just MSI remapping resources + * @domain: IOMMU domain to prepare + * @base: Start address of IOVA region for MSI mappings + * + * Users who manage their own IOVA allocation and do not want DMA API support, + * but would still like to take advantage of automatic MSI remapping, can use + * this to initialise their own domain appropriately. Users should reserve a + * contiguous IOVA region, starting at @base, large enough to accommodate the + * number of PAGE_SIZE mappings necessary to cover every MSI doorbell address + * used by the devices attached to @domain. + */ +int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base) +{ struct iommu_dma_cookie *cookie; + if (domain->type != IOMMU_DOMAIN_UNMANAGED) + return -EINVAL; + if (domain->iova_cookie) return -EEXIST; - cookie = kzalloc(sizeof(*cookie), GFP_KERNEL); + cookie = cookie_alloc(IOMMU_DMA_MSI_COOKIE); if (!cookie) return -ENOMEM; - spin_lock_init(&cookie->msi_lock); - INIT_LIST_HEAD(&cookie->msi_page_list); + cookie->msi_iova = base; domain->iova_cookie = cookie; return 0; } -EXPORT_SYMBOL(iommu_get_dma_cookie); +EXPORT_SYMBOL(iommu_get_msi_cookie); /** * iommu_put_dma_cookie - Release a domain's DMA mapping resources - * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() + * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() or + * iommu_get_msi_cookie() * * IOMMU drivers should normally call this from their domain_free callback. */ @@ -92,7 +155,7 @@ void iommu_put_dma_cookie(struct iommu_domain *domain) if (!cookie) return; - if (cookie->iovad.granule) + if (cookie->type == IOMMU_DMA_IOVA_COOKIE && cookie->iovad.granule) put_iova_domain(&cookie->iovad); list_for_each_entry_safe(msi, tmp, &cookie->msi_page_list, list) { @@ -137,11 +200,12 @@ static void iova_reserve_pci_windows(struct pci_dev *dev, int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size, struct device *dev) { - struct iova_domain *iovad = cookie_iovad(domain); + struct iommu_dma_cookie *cookie = domain->iova_cookie; + struct iova_domain *iovad = &cookie->iovad; unsigned long order, base_pfn, end_pfn; - if (!iovad) - return -ENODEV; + if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE) + return -EINVAL; /* Use the smallest supported page size for IOVA granularity */ order = __ffs(domain->pgsize_bitmap); @@ -662,11 +726,12 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev, { struct iommu_dma_cookie *cookie = domain->iova_cookie; struct iommu_dma_msi_page *msi_page; - struct iova_domain *iovad = &cookie->iovad; + struct iova_domain *iovad = cookie_iovad(domain); struct iova *iova; int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; + size_t size = cookie_msi_granule(cookie); - msi_addr &= ~(phys_addr_t)iova_mask(iovad); + msi_addr &= ~(phys_addr_t)(size - 1); list_for_each_entry(msi_page, &cookie->msi_page_list, list) if (msi_page->phys == msi_addr) return msi_page; @@ -675,13 +740,18 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev, if (!msi_page) return NULL; - iova = __alloc_iova(domain, iovad->granule, dma_get_mask(dev)); - if (!iova) - goto out_free_page; - msi_page->phys = msi_addr; - msi_page->iova = iova_dma_addr(iovad, iova); - if (iommu_map(domain, msi_page->iova, msi_addr, iovad->granule, prot)) + if (iovad) { + iova = __alloc_iova(domain, size, dma_get_mask(dev)); + if (!iova) + goto out_free_page; + msi_page->iova = iova_dma_addr(iovad, iova); + } else { + msi_page->iova = cookie->msi_iova; + cookie->msi_iova += size; + } + + if (iommu_map(domain, msi_page->iova, msi_addr, size, prot)) goto out_free_iova; INIT_LIST_HEAD(&msi_page->list); @@ -689,7 +759,10 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev, return msi_page; out_free_iova: - __free_iova(iovad, iova); + if (iovad) + __free_iova(iovad, iova); + else + cookie->msi_iova -= size; out_free_page: kfree(msi_page); return NULL; @@ -730,7 +803,7 @@ void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg) msg->data = ~0U; } else { msg->address_hi = upper_32_bits(msi_page->iova); - msg->address_lo &= iova_mask(&cookie->iovad); + msg->address_lo &= cookie_msi_granule(cookie) - 1; msg->address_lo += lower_32_bits(msi_page->iova); } } diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h index 7f7e9a7e3839..28df844a23b6 100644 --- a/include/linux/dma-iommu.h +++ b/include/linux/dma-iommu.h @@ -27,6 +27,7 @@ int iommu_dma_init(void); /* Domain management interface for IOMMU drivers */ int iommu_get_dma_cookie(struct iommu_domain *domain); +int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base); void iommu_put_dma_cookie(struct iommu_domain *domain); /* Setup call for arch DMA mapping code */ @@ -86,6 +87,11 @@ static inline int iommu_get_dma_cookie(struct iommu_domain *domain) return -ENODEV; } +static inline int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base) +{ + return -ENODEV; +} + static inline void iommu_put_dma_cookie(struct iommu_domain *domain) { } |