diff mbox

[4/7,v5] iommu: arm-smmu: Add support for the fsl-mc bus

Message ID 1526824191-7000-5-git-send-email-nipun.gupta@nxp.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Nipun Gupta May 20, 2018, 1:49 p.m. UTC
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@nxp.com>
---
 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(+)

Comments

Robin Murphy July 3, 2018, 4:01 p.m. UTC | #1
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@nxp.com>
> ---
>   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
>
diff mbox

Patch

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)) {
+		group = iommu_group_alloc();
+		if (IS_ERR(group))
+			return NULL;
+	} else {
+		get_device(cont_dev);
+		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