Re: [PATCH v2 05/12] ACPI/IORT: Add an input ID to acpi_dma_configure()

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Fri, Jun 19, 2020 at 09:20:06AM +0100, Lorenzo Pieralisi wrote:
> Some HW devices are created as child devices of proprietary busses,
> that have a bus specific policy defining how the child devices
> wires representing the devices ID are translated into IOMMU and
> IRQ controllers device IDs.
> 
> Current IORT code provides translations for:
> 
> - PCI devices, where the device ID is well identified at bus level
>   as the requester ID (RID)
> - Platform devices that are endpoint devices where the device ID is
>   retrieved from the ACPI object IORT mappings (Named components single
>   mappings). A platform device is represented in IORT as a named
>   component node
> 
> For devices that are child devices of proprietary busses the IORT
> firmware represents the bus node as a named component node in IORT
> and it is up to that named component node to define in/out bus
> specific ID translations for the bus child devices that are
> allocated and created in a bus specific manner.
> 
> In order to make IORT ID translations available for proprietary
> bus child devices, the current ACPI (and IORT) code must be
> augmented to provide an additional ID parameter to acpi_dma_configure()
> representing the child devices input ID. This ID is bus specific
> and it is retrieved in bus specific code.
> 
> By adding an ID parameter to acpi_dma_configure(), the IORT
> code can map the child device ID to an IOMMU stream ID through
> the IORT named component representing the bus in/out ID mappings.
> 
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Hanjun Guo <guohanjun@huawei.com>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> ---
>  drivers/acpi/arm64/iort.c | 59 +++++++++++++++++++++++++++++----------
>  drivers/acpi/scan.c       |  8 ++++--
>  include/acpi/acpi_bus.h   |  9 ++++--
>  include/linux/acpi.h      |  7 +++++
>  include/linux/acpi_iort.h |  7 +++--
>  5 files changed, 67 insertions(+), 23 deletions(-)

Hi Rafael,

just to ask if the ACPI core changes in this patch are OK with you,
thank you very much.

Lorenzo

> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 421c6976ab81..ec782e4a0fe4 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -978,19 +978,54 @@ static void iort_named_component_init(struct device *dev,
>  					   nc->node_flags);
>  }
>  
> +static int iort_nc_iommu_map(struct device *dev, struct acpi_iort_node *node)
> +{
> +	struct acpi_iort_node *parent;
> +	int err = -ENODEV, i = 0;
> +	u32 streamid = 0;
> +
> +	do {
> +
> +		parent = iort_node_map_platform_id(node, &streamid,
> +						   IORT_IOMMU_TYPE,
> +						   i++);
> +
> +		if (parent)
> +			err = iort_iommu_xlate(dev, parent, streamid);
> +	} while (parent && !err);
> +
> +	return err;
> +}
> +
> +static int iort_nc_iommu_map_id(struct device *dev,
> +				struct acpi_iort_node *node,
> +				const u32 *in_id)
> +{
> +	struct acpi_iort_node *parent;
> +	u32 streamid;
> +
> +	parent = iort_node_map_id(node, *in_id, &streamid, IORT_IOMMU_TYPE);
> +	if (parent)
> +		return iort_iommu_xlate(dev, parent, streamid);
> +
> +	return -ENODEV;
> +}
> +
> +
>  /**
> - * iort_iommu_configure - Set-up IOMMU configuration for a device.
> + * iort_iommu_configure_id - Set-up IOMMU configuration for a device.
>   *
>   * @dev: device to configure
> + * @id_in: optional input id const value pointer
>   *
>   * Returns: iommu_ops pointer on configuration success
>   *          NULL on configuration failure
>   */
> -const struct iommu_ops *iort_iommu_configure(struct device *dev)
> +const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
> +						const u32 *id_in)
>  {
> -	struct acpi_iort_node *node, *parent;
> +	struct acpi_iort_node *node;
>  	const struct iommu_ops *ops;
> -	u32 streamid = 0;
>  	int err = -ENODEV;
>  
>  	/*
> @@ -1019,21 +1054,13 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
>  		if (fwspec && iort_pci_rc_supports_ats(node))
>  			fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;
>  	} else {
> -		int i = 0;
> -
>  		node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
>  				      iort_match_node_callback, dev);
>  		if (!node)
>  			return NULL;
>  
> -		do {
> -			parent = iort_node_map_platform_id(node, &streamid,
> -							   IORT_IOMMU_TYPE,
> -							   i++);
> -
> -			if (parent)
> -				err = iort_iommu_xlate(dev, parent, streamid);
> -		} while (parent && !err);
> +		err = id_in ? iort_nc_iommu_map_id(dev, node, id_in) :
> +			      iort_nc_iommu_map(dev, node);
>  
>  		if (!err)
>  			iort_named_component_init(dev, node);
> @@ -1058,6 +1085,7 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
>  
>  	return ops;
>  }
> +
>  #else
>  static inline const struct iommu_ops *iort_fwspec_iommu_ops(struct device *dev)
>  { return NULL; }
> @@ -1066,7 +1094,8 @@ static inline int iort_add_device_replay(const struct iommu_ops *ops,
>  { return 0; }
>  int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
>  { return 0; }
> -const struct iommu_ops *iort_iommu_configure(struct device *dev)
> +const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
> +						const u32 *input_id)
>  { return NULL; }
>  #endif
>  
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 8777faced51a..2142f1554761 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1457,8 +1457,10 @@ int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
>   * acpi_dma_configure - Set-up DMA configuration for the device.
>   * @dev: The pointer to the device
>   * @attr: device dma attributes
> + * @input_id: input device id const value pointer
>   */
> -int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
> +int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
> +			  const u32 *input_id)
>  {
>  	const struct iommu_ops *iommu;
>  	u64 dma_addr = 0, size = 0;
> @@ -1470,7 +1472,7 @@ int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
>  
>  	iort_dma_setup(dev, &dma_addr, &size);
>  
> -	iommu = iort_iommu_configure(dev);
> +	iommu = iort_iommu_configure_id(dev, input_id);
>  	if (PTR_ERR(iommu) == -EPROBE_DEFER)
>  		return -EPROBE_DEFER;
>  
> @@ -1479,7 +1481,7 @@ int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
>  
>  	return 0;
>  }
> -EXPORT_SYMBOL_GPL(acpi_dma_configure);
> +EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
>  
>  static void acpi_init_coherency(struct acpi_device *adev)
>  {
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 5afb6ceb284f..a3abcc4b7d9f 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -588,8 +588,13 @@ bool acpi_dma_supported(struct acpi_device *adev);
>  enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev);
>  int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
>  		       u64 *size);
> -int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr);
> -
> +int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
> +			   const u32 *input_id);
> +static inline int acpi_dma_configure(struct device *dev,
> +				     enum dev_dma_attr attr)
> +{
> +	return acpi_dma_configure_id(dev, attr, NULL);
> +}
>  struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
>  					   u64 address, bool check_children);
>  int acpi_is_root_bridge(acpi_handle);
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index d661cd0ee64d..6d2c47489d90 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -905,6 +905,13 @@ static inline int acpi_dma_configure(struct device *dev,
>  	return 0;
>  }
>  
> +static inline int acpi_dma_configure_id(struct device *dev,
> +					enum dev_dma_attr attr,
> +					const u32 *input_id)
> +{
> +	return 0;
> +}
> +
>  #define ACPI_PTR(_ptr)	(NULL)
>  
>  static inline void acpi_device_set_enumerated(struct acpi_device *adev)
> diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
> index e51425e083da..20a32120bb88 100644
> --- a/include/linux/acpi_iort.h
> +++ b/include/linux/acpi_iort.h
> @@ -35,7 +35,8 @@ void acpi_configure_pmsi_domain(struct device *dev);
>  int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id);
>  /* IOMMU interface */
>  void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *size);
> -const struct iommu_ops *iort_iommu_configure(struct device *dev);
> +const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
> +						const u32 *id_in);
>  int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head);
>  #else
>  static inline void acpi_iort_init(void) { }
> @@ -48,8 +49,8 @@ static inline void acpi_configure_pmsi_domain(struct device *dev) { }
>  /* IOMMU interface */
>  static inline void iort_dma_setup(struct device *dev, u64 *dma_addr,
>  				  u64 *size) { }
> -static inline const struct iommu_ops *iort_iommu_configure(
> -				      struct device *dev)
> +static inline const struct iommu_ops *iort_iommu_configure_id(
> +				      struct device *dev, const u32 *id_in)
>  { return NULL; }
>  static inline
>  int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
> -- 
> 2.26.1
>