[PATCH 6/6] iommu/arm-smmu: Introduce iommu_group notifier block
From: Andreas Herrmann <hidden>
Date: 2014-01-30 18:18:09
Also in:
linux-iommu
Subsystem:
iommu subsystem, the rest · Maintainers:
Joerg Roedel, Will Deacon, Linus Torvalds
At the moment just handle IOMMU_GROUP_NOTIFY_BIND_DRIVER to conditionally isolate all master devices for an SMMU. Depending on DT information each device is put into its own protection domain (if possible). For configuration with one or just a few masters per SMMU that is easy to achieve. In case of many devices per SMMU (e.g. MMU-500 with it's distributed translation support) isolation of each device might not be possible -- depending on number of available SMR groups and/or context banks. Default is that device isolation is contolled per SMMU with SMMU node property "arm,smmu-isolate-devices" in a DT. If this property is set for an SMMU node, device isolation is performed. W/o device isolation the driver detects SMMUs but no translation is configured (transactions just bypass translation process). Note that for device isolation dma_base and size are fixed as 0 and SZ_128M at the moment. Additional patches will address this restriction and allow automatic growth of mapping size. Cc: Varun Sethi <redacted> Cc: Andreas Herrmann <redacted> Signed-off-by: Andreas Herrmann <redacted> --- drivers/iommu/arm-smmu.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index d1f166f..bee88c8 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c@@ -47,6 +47,7 @@ #include <linux/amba/bus.h> #include <asm/pgalloc.h> +#include <asm/dma-iommu.h> /* Maximum number of stream IDs assigned to a single device */ #define MAX_MASTER_STREAMIDS MAX_PHANDLE_ARGS
@@ -1677,6 +1678,47 @@ static int arm_smmu_domain_has_cap(struct iommu_domain *domain, return !!(cap & caps); } +static int arm_smmu_group_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = data; + struct dma_iommu_mapping *mapping; + struct arm_smmu_device *smmu; + int ret; + + switch (action) { + case IOMMU_GROUP_NOTIFY_BIND_DRIVER: + + smmu = dev->archdata.iommu; + if (!smmu || !(smmu->options & ARM_SMMU_OPT_ISOLATE_DEVICES)) + break; + + mapping = arm_iommu_create_mapping(&platform_bus_type, + 0, SZ_128M, 0); + if (IS_ERR(mapping)) { + ret = PTR_ERR(mapping); + dev_info(dev, "arm_iommu_create_mapping failed\n"); + break; + } + + ret = arm_iommu_attach_device(dev, mapping); + if (ret < 0) { + dev_info(dev, "arm_iommu_attach_device failed\n"); + arm_iommu_release_mapping(mapping); + } + + break; + default: + break; + } + + return 0; +} + +static struct notifier_block group_nb = { + .notifier_call = arm_smmu_group_notifier, +}; + static int arm_smmu_add_device(struct device *dev) { struct arm_smmu_device *child, *parent, *smmu;
@@ -1726,6 +1768,8 @@ static int arm_smmu_add_device(struct device *dev) return PTR_ERR(group); } + iommu_group_register_notifier(group, &group_nb); + ret = iommu_group_add_device(group, dev); iommu_group_put(group); dev->archdata.iommu = smmu;
--
1.7.9.5