[RFC PATCH 4/6] iommu/arm-smmu: Add support for IOMMU_DOMAIN_DMA in SMMUv1/SMMUv2 driver
From: Anup Patel <hidden>
Date: 2016-01-27 05:21:58
Also in:
linux-devicetree, linux-iommu, lkml
Subsystem:
iommu subsystem, the rest · Maintainers:
Joerg Roedel, Will Deacon, Linus Torvalds
To allow use of large memory (> 4Gb) with 32bit devices we need to use some kind of iommu for such 32bit devices. This patch extends SMMUv1/SMMUv2 driver to support DMA domains which in-turn will allows us to use iommu based DMA mappings for 32bit devices. Signed-off-by: Anup Patel <redacted> Reviewed-by: Ray Jui <rjui@broadcom.com> Reviewed-by: Scott Branden <sbranden@broadcom.com> --- drivers/iommu/arm-smmu.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 9bdf6b2..43424fe 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c@@ -29,6 +29,7 @@ #define pr_fmt(fmt) "arm-smmu: " fmt #include <linux/delay.h> +#include <linux/dma-iommu.h> #include <linux/dma-mapping.h> #include <linux/err.h> #include <linux/interrupt.h>
@@ -967,7 +968,7 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type) { struct arm_smmu_domain *smmu_domain; - if (type != IOMMU_DOMAIN_UNMANAGED) + if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA) return NULL; /* * Allocate the domain and initialise some of its data structures.
@@ -978,6 +979,12 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type) if (!smmu_domain) return NULL; + if (type == IOMMU_DOMAIN_DMA && + iommu_get_dma_cookie(&smmu_domain->domain)) { + kfree(smmu_domain); + return NULL; + } + mutex_init(&smmu_domain->init_mutex); spin_lock_init(&smmu_domain->pgtbl_lock);
@@ -992,6 +999,7 @@ static void arm_smmu_domain_free(struct iommu_domain *domain) * Free the domain resources. We assume that all devices have * already been detached. */ + iommu_put_dma_cookie(domain); arm_smmu_destroy_domain_context(domain); kfree(smmu_domain); }
@@ -1361,6 +1369,16 @@ static int arm_smmu_init_platform_device(struct device *dev, return 0; } +int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args) +{ + /* + * Nothing to do here because SMMU is already aware of all + * MMU masters and their stream IDs using mmu-master attibute + * SMMU DT node. + */ + return 0; +} + static int arm_smmu_add_device(struct device *dev) { struct iommu_group *group;
@@ -1458,6 +1476,7 @@ static struct iommu_ops arm_smmu_ops = { .unmap = arm_smmu_unmap, .map_sg = default_iommu_map_sg, .iova_to_phys = arm_smmu_iova_to_phys, + .of_xlate = arm_smmu_of_xlate, .add_device = arm_smmu_add_device, .remove_device = arm_smmu_remove_device, .device_group = arm_smmu_device_group,
--
1.9.1