diff mbox

[v7,08/10] iommu/dma-reserved_iommu: iommu_msi_mapping_desc_to_domain

Message ID 1461084994-2355-9-git-send-email-eric.auger@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Eric Auger April 19, 2016, 4:56 p.m. UTC
This function checks whether
- the device emitting the MSI belongs to a non default iommu domain
- the iommu domain requires the MSI address to be mapped.

If those conditions are met, the function returns the iommu domain
to be used for mapping the MSI doorbell; else it returns NULL.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
---
 drivers/iommu/dma-reserved-iommu.c | 19 +++++++++++++++++++
 include/linux/dma-reserved-iommu.h | 18 ++++++++++++++++++
 2 files changed, 37 insertions(+)

Comments

Robin Murphy April 20, 2016, 5:19 p.m. UTC | #1
On 19/04/16 17:56, Eric Auger wrote:
> This function checks whether
> - the device emitting the MSI belongs to a non default iommu domain
> - the iommu domain requires the MSI address to be mapped.
>
> If those conditions are met, the function returns the iommu domain
> to be used for mapping the MSI doorbell; else it returns NULL.
>
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> ---
>   drivers/iommu/dma-reserved-iommu.c | 19 +++++++++++++++++++
>   include/linux/dma-reserved-iommu.h | 18 ++++++++++++++++++
>   2 files changed, 37 insertions(+)
>
> diff --git a/drivers/iommu/dma-reserved-iommu.c b/drivers/iommu/dma-reserved-iommu.c
> index 2522235..907a17f 100644
> --- a/drivers/iommu/dma-reserved-iommu.c
> +++ b/drivers/iommu/dma-reserved-iommu.c
> @@ -17,6 +17,7 @@
>
>   #include <linux/iommu.h>
>   #include <linux/iova.h>
> +#include <linux/msi.h>
>
>   struct reserved_iova_domain {
>   	struct iova_domain *iovad;
> @@ -332,3 +333,21 @@ unlock:
>   }
>   EXPORT_SYMBOL_GPL(iommu_put_reserved_iova);
>
> +struct iommu_domain *iommu_msi_mapping_desc_to_domain(struct msi_desc *desc)
> +{
> +	struct device *dev;
> +	struct iommu_domain *d;
> +
> +	dev = msi_desc_to_dev(desc);
> +
> +	d = iommu_get_domain_for_dev(dev);
> +
> +	if (!d || (d->type == IOMMU_DOMAIN_DMA))
> +		return NULL;
> +
> +	if (iommu_domain_get_attr(d, DOMAIN_ATTR_MSI_MAPPING, NULL))
> +		return NULL;

Yeah, I don't see why we couldn't just use

if (domain->ops->capable(IOMMU_CAP_INTR_REMAP))
	return NULL

there instead.

> +
> +	return d;
> +}
> +EXPORT_SYMBOL_GPL(iommu_msi_mapping_desc_to_domain);
> diff --git a/include/linux/dma-reserved-iommu.h b/include/linux/dma-reserved-iommu.h
> index 8722131..8373929 100644
> --- a/include/linux/dma-reserved-iommu.h
> +++ b/include/linux/dma-reserved-iommu.h
> @@ -19,6 +19,7 @@
>   #include <linux/kernel.h>
>
>   struct iommu_domain;
> +struct msi_desc;
>
>   #ifdef CONFIG_IOMMU_DMA_RESERVED
>
> @@ -70,6 +71,17 @@ int iommu_get_reserved_iova(struct iommu_domain *domain,
>    * if the binding ref count is null, destroy the reserved mapping
>    */
>   void iommu_put_reserved_iova(struct iommu_domain *domain, phys_addr_t addr);
> +
> +/**
> + * iommu_msi_mapping_desc_to_domain: in case the MSI originates from a device
> + * upstream to an IOMMU and this IOMMU translates the MSI transaction,
> + * this function returns the iommu domain the MSI doorbell address must be
> + * mapped in. Else it returns NULL.
> + *
> + * @desc: msi desc handle
> + */
> +struct iommu_domain *iommu_msi_mapping_desc_to_domain(struct msi_desc *desc);
> +
>   #else
>
>   static inline int
> @@ -93,5 +105,11 @@ static inline int iommu_get_reserved_iova(struct iommu_domain *domain,
>   static inline void iommu_put_reserved_iova(struct iommu_domain *domain,
>   					   phys_addr_t addr) {}
>
> +static inline struct iommu_domain *
> +iommu_msi_mapping_desc_to_domain(struct msi_desc *desc)
> +{
> +	return NULL;
> +}
> +
>   #endif	/* CONFIG_IOMMU_DMA_RESERVED */
>   #endif	/* __DMA_RESERVED_IOMMU_H */
>
Eric Auger April 21, 2016, 8:40 a.m. UTC | #2
Hi Robin,
On 04/20/2016 07:19 PM, Robin Murphy wrote:
> On 19/04/16 17:56, Eric Auger wrote:
>> This function checks whether
>> - the device emitting the MSI belongs to a non default iommu domain
>> - the iommu domain requires the MSI address to be mapped.
>>
>> If those conditions are met, the function returns the iommu domain
>> to be used for mapping the MSI doorbell; else it returns NULL.
>>
>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>> ---
>>   drivers/iommu/dma-reserved-iommu.c | 19 +++++++++++++++++++
>>   include/linux/dma-reserved-iommu.h | 18 ++++++++++++++++++
>>   2 files changed, 37 insertions(+)
>>
>> diff --git a/drivers/iommu/dma-reserved-iommu.c
>> b/drivers/iommu/dma-reserved-iommu.c
>> index 2522235..907a17f 100644
>> --- a/drivers/iommu/dma-reserved-iommu.c
>> +++ b/drivers/iommu/dma-reserved-iommu.c
>> @@ -17,6 +17,7 @@
>>
>>   #include <linux/iommu.h>
>>   #include <linux/iova.h>
>> +#include <linux/msi.h>
>>
>>   struct reserved_iova_domain {
>>       struct iova_domain *iovad;
>> @@ -332,3 +333,21 @@ unlock:
>>   }
>>   EXPORT_SYMBOL_GPL(iommu_put_reserved_iova);
>>
>> +struct iommu_domain *iommu_msi_mapping_desc_to_domain(struct msi_desc
>> *desc)
>> +{
>> +    struct device *dev;
>> +    struct iommu_domain *d;
>> +
>> +    dev = msi_desc_to_dev(desc);
>> +
>> +    d = iommu_get_domain_for_dev(dev);
>> +
>> +    if (!d || (d->type == IOMMU_DOMAIN_DMA))
>> +        return NULL;
>> +
>> +    if (iommu_domain_get_attr(d, DOMAIN_ATTR_MSI_MAPPING, NULL))
>> +        return NULL;
> 
> Yeah, I don't see why we couldn't just use
> 
> if (domain->ops->capable(IOMMU_CAP_INTR_REMAP))
>     return NULL
I don't think this works. This will lead to MSI iommu mapping on x86
when irq_remapping is disabled. To be further checked though.

Eric
> 
> there instead.
> 
>> +
>> +    return d;
>> +}
>> +EXPORT_SYMBOL_GPL(iommu_msi_mapping_desc_to_domain);
>> diff --git a/include/linux/dma-reserved-iommu.h
>> b/include/linux/dma-reserved-iommu.h
>> index 8722131..8373929 100644
>> --- a/include/linux/dma-reserved-iommu.h
>> +++ b/include/linux/dma-reserved-iommu.h
>> @@ -19,6 +19,7 @@
>>   #include <linux/kernel.h>
>>
>>   struct iommu_domain;
>> +struct msi_desc;
>>
>>   #ifdef CONFIG_IOMMU_DMA_RESERVED
>>
>> @@ -70,6 +71,17 @@ int iommu_get_reserved_iova(struct iommu_domain
>> *domain,
>>    * if the binding ref count is null, destroy the reserved mapping
>>    */
>>   void iommu_put_reserved_iova(struct iommu_domain *domain,
>> phys_addr_t addr);
>> +
>> +/**
>> + * iommu_msi_mapping_desc_to_domain: in case the MSI originates from
>> a device
>> + * upstream to an IOMMU and this IOMMU translates the MSI transaction,
>> + * this function returns the iommu domain the MSI doorbell address
>> must be
>> + * mapped in. Else it returns NULL.
>> + *
>> + * @desc: msi desc handle
>> + */
>> +struct iommu_domain *iommu_msi_mapping_desc_to_domain(struct msi_desc
>> *desc);
>> +
>>   #else
>>
>>   static inline int
>> @@ -93,5 +105,11 @@ static inline int iommu_get_reserved_iova(struct
>> iommu_domain *domain,
>>   static inline void iommu_put_reserved_iova(struct iommu_domain *domain,
>>                          phys_addr_t addr) {}
>>
>> +static inline struct iommu_domain *
>> +iommu_msi_mapping_desc_to_domain(struct msi_desc *desc)
>> +{
>> +    return NULL;
>> +}
>> +
>>   #endif    /* CONFIG_IOMMU_DMA_RESERVED */
>>   #endif    /* __DMA_RESERVED_IOMMU_H */
>>
>
diff mbox

Patch

diff --git a/drivers/iommu/dma-reserved-iommu.c b/drivers/iommu/dma-reserved-iommu.c
index 2522235..907a17f 100644
--- a/drivers/iommu/dma-reserved-iommu.c
+++ b/drivers/iommu/dma-reserved-iommu.c
@@ -17,6 +17,7 @@ 
 
 #include <linux/iommu.h>
 #include <linux/iova.h>
+#include <linux/msi.h>
 
 struct reserved_iova_domain {
 	struct iova_domain *iovad;
@@ -332,3 +333,21 @@  unlock:
 }
 EXPORT_SYMBOL_GPL(iommu_put_reserved_iova);
 
+struct iommu_domain *iommu_msi_mapping_desc_to_domain(struct msi_desc *desc)
+{
+	struct device *dev;
+	struct iommu_domain *d;
+
+	dev = msi_desc_to_dev(desc);
+
+	d = iommu_get_domain_for_dev(dev);
+
+	if (!d || (d->type == IOMMU_DOMAIN_DMA))
+		return NULL;
+
+	if (iommu_domain_get_attr(d, DOMAIN_ATTR_MSI_MAPPING, NULL))
+		return NULL;
+
+	return d;
+}
+EXPORT_SYMBOL_GPL(iommu_msi_mapping_desc_to_domain);
diff --git a/include/linux/dma-reserved-iommu.h b/include/linux/dma-reserved-iommu.h
index 8722131..8373929 100644
--- a/include/linux/dma-reserved-iommu.h
+++ b/include/linux/dma-reserved-iommu.h
@@ -19,6 +19,7 @@ 
 #include <linux/kernel.h>
 
 struct iommu_domain;
+struct msi_desc;
 
 #ifdef CONFIG_IOMMU_DMA_RESERVED
 
@@ -70,6 +71,17 @@  int iommu_get_reserved_iova(struct iommu_domain *domain,
  * if the binding ref count is null, destroy the reserved mapping
  */
 void iommu_put_reserved_iova(struct iommu_domain *domain, phys_addr_t addr);
+
+/**
+ * iommu_msi_mapping_desc_to_domain: in case the MSI originates from a device
+ * upstream to an IOMMU and this IOMMU translates the MSI transaction,
+ * this function returns the iommu domain the MSI doorbell address must be
+ * mapped in. Else it returns NULL.
+ *
+ * @desc: msi desc handle
+ */
+struct iommu_domain *iommu_msi_mapping_desc_to_domain(struct msi_desc *desc);
+
 #else
 
 static inline int
@@ -93,5 +105,11 @@  static inline int iommu_get_reserved_iova(struct iommu_domain *domain,
 static inline void iommu_put_reserved_iova(struct iommu_domain *domain,
 					   phys_addr_t addr) {}
 
+static inline struct iommu_domain *
+iommu_msi_mapping_desc_to_domain(struct msi_desc *desc)
+{
+	return NULL;
+}
+
 #endif	/* CONFIG_IOMMU_DMA_RESERVED */
 #endif	/* __DMA_RESERVED_IOMMU_H */