On 20/05/18 14:49, Nipun Gupta wrote:
Implement bus specific support for the fsl-mc bus including
registering arm_smmu_ops and bus specific device add operations.
Signed-off-by: Nipun Gupta <nipun.gupta@xxxxxxx>
---
drivers/iommu/arm-smmu.c | 7 +++++++
drivers/iommu/iommu.c | 21 +++++++++++++++++++++
include/linux/fsl/mc.h | 8 ++++++++
include/linux/iommu.h | 2 ++
4 files changed, 38 insertions(+)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 69e7c60..e1d5090 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -52,6 +52,7 @@
#include <linux/spinlock.h>
#include <linux/amba/bus.h>
+#include <linux/fsl/mc.h>
#include "io-pgtable.h"
#include "arm-smmu-regs.h"
@@ -1459,6 +1460,8 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
if (dev_is_pci(dev))
group = pci_device_group(dev);
+ else if (dev_is_fsl_mc(dev))
+ group = fsl_mc_device_group(dev);
else
group = generic_device_group(dev);
@@ -2037,6 +2040,10 @@ static void arm_smmu_bus_init(void)
bus_set_iommu(&pci_bus_type, &arm_smmu_ops);
}
#endif
+#ifdef CONFIG_FSL_MC_BUS
+ if (!iommu_present(&fsl_mc_bus_type))
+ bus_set_iommu(&fsl_mc_bus_type, &arm_smmu_ops);
+#endif
}
static int arm_smmu_device_probe(struct platform_device *pdev)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index d2aa2320..6d4ce35 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -32,6 +32,7 @@
#include <linux/pci.h>
#include <linux/bitops.h>
#include <linux/property.h>
+#include <linux/fsl/mc.h>
#include <trace/events/iommu.h>
static struct kset *iommu_group_kset;
@@ -987,6 +988,26 @@ struct iommu_group *pci_device_group(struct device *dev)
return iommu_group_alloc();
}
+/* Get the IOMMU group for device on fsl-mc bus */
+struct iommu_group *fsl_mc_device_group(struct device *dev)
+{
+ struct device *cont_dev = fsl_mc_cont_dev(dev);
+ struct iommu_group *group;
+
+ /* Container device is responsible for creating the iommu group */
+ if (fsl_mc_is_cont_dev(dev)) {
Why duplicate what fsl_mc_cont_dev() has already figured out?
AFAICS the overall operation here boils down to something like:
cont_dev = fsl_mc_cont_dev(dev);
group = iommu_group_get(cont_dev);
if (!group)
group = iommu_group_alloc();
return group;
+ group = iommu_group_alloc();
+ if (IS_ERR(group))
+ return NULL;
iommu_group_get_for_dev() expects a PTR_ERR, so I don't think munging
the return here is the right thing to do.
+ } else {
+ get_device(cont_dev);
If races are a concern, isn't this a bit late? Maybe in that case you
want {get,put}_fsl_mc_cont_dev() routines instead of the simple macro
below. But on the other hand if dev already has cont_dev as its parent,
wouldn't the reference taken in device_add() be sufficient to prevent it
from vanishing unexpectedly in this timescale?
Robin.
+ group = iommu_group_get(cont_dev);
+ put_device(cont_dev);
+ }
+
+ return group;
+}
+
/**
* iommu_group_get_for_dev - Find or create the IOMMU group for a device
* @dev: target device
diff --git a/include/linux/fsl/mc.h b/include/linux/fsl/mc.h
index f27cb14..dddaca1 100644
--- a/include/linux/fsl/mc.h
+++ b/include/linux/fsl/mc.h
@@ -351,6 +351,14 @@ struct fsl_mc_io {
#define dev_is_fsl_mc(_dev) (0)
#endif
+/* Macro to check if a device is a container device */
+#define fsl_mc_is_cont_dev(_dev) (to_fsl_mc_device(_dev)->flags & \
+ FSL_MC_IS_DPRC)
+
+/* Macro to get the container device of a MC device */
+#define fsl_mc_cont_dev(_dev) (fsl_mc_is_cont_dev(_dev) ? \
+ (_dev) : (_dev)->parent)
+
/*
* module_fsl_mc_driver() - Helper macro for drivers that don't do
* anything special in module init/exit. This eliminates a lot of
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 19938ee..2981200 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -389,6 +389,8 @@ static inline size_t iommu_map_sg(struct iommu_domain *domain,
extern struct iommu_group *pci_device_group(struct device *dev);
/* Generic device grouping function */
extern struct iommu_group *generic_device_group(struct device *dev);
+/* FSL-MC device grouping function */
+struct iommu_group *fsl_mc_device_group(struct device *dev);
/**
* struct iommu_fwspec - per-device IOMMU instance data
--
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