exynos allocates a per-device struct in the of_xlate() that can point to multiple instances of the iommu. It looks like each iommu instance can point to only one device however.
Move the allocation of the per-device struct to the top of probe and use iommu_of_xlate() to fill in the linked list. Rely on the core code to locate the iommu. Solve a few issues: - A bus probe was failing by accident because the of_xlate not being called left a NULL owner in the priv, and other code tended to free the dev->iommu. iommu_of_xlate() will fail bus probe directly - Missing validation that the node in the iommus instance is actually pointing at this driver - Don't leak the owner. It is allocated during probe, freed on probe failure, and freed in release_device() on probe success. Previously it would allocate it in of_xlate and leak it in some possible error flows. Signed-off-by: Jason Gunthorpe <[email protected]> --- drivers/iommu/exynos-iommu.c | 79 +++++++++++++++++------------------- 1 file changed, 38 insertions(+), 41 deletions(-) diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c index 2c6e9094f1e979..c301aa87fe0ff0 100644 --- a/drivers/iommu/exynos-iommu.c +++ b/drivers/iommu/exynos-iommu.c @@ -13,6 +13,7 @@ #include <linux/err.h> #include <linux/io.h> #include <linux/iommu.h> +#include <linux/iommu-driver.h> #include <linux/interrupt.h> #include <linux/kmemleak.h> #include <linux/list.h> @@ -26,6 +27,9 @@ typedef u32 sysmmu_iova_t; typedef u32 sysmmu_pte_t; static struct iommu_domain exynos_identity_domain; +static int exynos_iommu_of_xlate(struct iommu_device *iommu, + struct of_phandle_args *args, void *priv); + /* We do not consider super section mapping (16MB) */ #define SECT_ORDER 20 #define LPAGE_ORDER 16 @@ -168,8 +172,6 @@ static u32 lv2ent_offset(sysmmu_iova_t iova) #define REG_V7_CAPA1 0x874 #define REG_V7_CTRL_VM 0x8000 -#define has_sysmmu(dev) (dev_iommu_priv_get(dev) != NULL) - static struct device *dma_dev; static struct kmem_cache *lv2table_kmem_cache; static sysmmu_pte_t *zero_lv2_table; @@ -779,8 +781,6 @@ static int exynos_sysmmu_probe(struct platform_device *pdev) if (ret) return ret; - platform_set_drvdata(pdev, data); - if (PG_ENT_SHIFT < 0) { if (MMU_MAJ_VER(data->version) < 5) { PG_ENT_SHIFT = SYSMMU_PG_ENT_SHIFT; @@ -1393,15 +1393,29 @@ static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *iommu_domain, return phys; } -static struct iommu_device *exynos_iommu_probe_device(struct device *dev) +static struct iommu_device * +exynos_iommu_probe_device(struct iommu_probe_info *pinf) { - struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev); + struct exynos_iommu_owner *owner; + struct device *dev = pinf->dev; struct sysmmu_drvdata *data; + int ret; - if (!has_sysmmu(dev)) - return ERR_PTR(-ENODEV); + owner = kzalloc(sizeof(*owner), GFP_KERNEL); + if (!owner) + return ERR_PTR(-ENOMEM); + + INIT_LIST_HEAD(&owner->controllers); + mutex_init(&owner->rpm_lock); + owner->domain = &exynos_identity_domain; + + ret = iommu_of_xlate(pinf, &exynos_iommu_ops, -1, + &exynos_iommu_of_xlate, owner); + if (ret) + goto err_free; list_for_each_entry(data, &owner->controllers, owner_node) { + data->master = dev; /* * SYSMMU will be runtime activated via device link * (dependency) to its master device, so there are no @@ -1412,11 +1426,17 @@ static struct iommu_device *exynos_iommu_probe_device(struct device *dev) DL_FLAG_PM_RUNTIME); } - /* There is always at least one entry, see exynos_iommu_of_xlate() */ + /* iommu_of_xlate() fails if there are no entries */ data = list_first_entry(&owner->controllers, struct sysmmu_drvdata, owner_node); + dev_iommu_priv_set(dev, owner); + return &data->iommu; + +err_free: + kfree(owner); + return ERR_PTR(ret); } static void exynos_iommu_release_device(struct device *dev) @@ -1430,42 +1450,19 @@ static void exynos_iommu_release_device(struct device *dev) device_link_del(data->link); } -static int exynos_iommu_of_xlate(struct device *dev, - struct of_phandle_args *spec) +static int exynos_iommu_of_xlate(struct iommu_device *iommu, + struct of_phandle_args *args, void *priv) { - struct platform_device *sysmmu = of_find_device_by_node(spec->np); - struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev); - struct sysmmu_drvdata *data, *entry; - - if (!sysmmu) - return -ENODEV; - - data = platform_get_drvdata(sysmmu); - if (!data) { - put_device(&sysmmu->dev); - return -ENODEV; - } - - if (!owner) { - owner = kzalloc(sizeof(*owner), GFP_KERNEL); - if (!owner) { - put_device(&sysmmu->dev); - return -ENOMEM; - } - - INIT_LIST_HEAD(&owner->controllers); - mutex_init(&owner->rpm_lock); - owner->domain = &exynos_identity_domain; - dev_iommu_priv_set(dev, owner); - } + struct sysmmu_drvdata *data = + container_of(iommu, struct sysmmu_drvdata, iommu); + struct exynos_iommu_owner *owner = priv; + struct sysmmu_drvdata *entry; + /* FIXME this relies on iommu_probe_device_lock */ list_for_each_entry(entry, &owner->controllers, owner_node) if (entry == data) return 0; - list_add_tail(&data->owner_node, &owner->controllers); - data->master = dev; - return 0; } @@ -1473,10 +1470,10 @@ static const struct iommu_ops exynos_iommu_ops = { .identity_domain = &exynos_identity_domain, .domain_alloc_paging = exynos_iommu_domain_alloc_paging, .device_group = generic_device_group, - .probe_device = exynos_iommu_probe_device, + .probe_device_pinf = exynos_iommu_probe_device, .release_device = exynos_iommu_release_device, .pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE, - .of_xlate = exynos_iommu_of_xlate, + .of_xlate = iommu_dummy_of_xlate, .default_domain_ops = &(const struct iommu_domain_ops) { .attach_dev = exynos_iommu_attach_device, .map_pages = exynos_iommu_map, -- 2.42.0
