linux-kernel - Re: [PATCH v9 10/15] ACPI: platform-msi: retrieve dev id from IORT

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Message-ID: <20170307143525.GA26990@red-moon>
Date:   Tue, 7 Mar 2017 14:35:25 +0000
From:   Lorenzo Pieralisi <lorenzo.pieralisi@....com>
To:     Hanjun Guo <guohanjun@...wei.com>
Cc:     Marc Zyngier <marc.zyngier@....com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        linux-acpi@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
        Greg KH <gregkh@...uxfoundation.org>,
        Tomasz Nowicki <tn@...ihalf.com>, Ma Jun <majun258@...wei.com>,
        Kefeng Wang <wangkefeng.wang@...wei.com>,
        Sinan Kaya <okaya@...eaurora.org>, huxinwei@...wei.com,
        yimin@...wei.com, linuxarm@...wei.com,
        Hanjun Guo <hanjun.guo@...aro.org>
Subject: Re: [PATCH v9 10/15] ACPI: platform-msi: retrieve dev id from IORT

On Tue, Mar 07, 2017 at 08:40:05PM +0800, Hanjun Guo wrote:
> From: Hanjun Guo <hanjun.guo@...aro.org>
> 
> For devices connecting to ITS, the devices need to identify themself
> through a dev id; this dev id is represented in the IORT table in named
> component node [1] for platform devices, so this patch adds code that
> scans the IORT table to retrieve the devices' dev id.
> 
> Leveraging the iort_node_map_platform_id() IORT API, add a new function
> call, iort_pmsi_get_dev_id() and use it in its_pmsi_prepare() to allow
> retrieving dev id in ACPI platforms.
> 
> [1]: https://static.docs.arm.com/den0049/b/DEN0049B_IO_Remapping_Table.pdf
> 
> Signed-off-by: Hanjun Guo <hanjun.guo@...aro.org>
> [lorenzo.pieralisi@....com: rewrote commit log]
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@....com>
> Tested-by: Ming Lei <ming.lei@...onical.com>
> Tested-by: Wei Xu <xuwei5@...ilicon.com>
> Tested-by: Sinan Kaya <okaya@...eaurora.org>
> Cc: Marc Zyngier <marc.zyngier@....com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@....com>
> Cc: Tomasz Nowicki <tn@...ihalf.com>
> Cc: Thomas Gleixner <tglx@...utronix.de>
> ---
>  drivers/acpi/arm64/iort.c                     | 24 ++++++++++++++++++++++++
>  drivers/irqchip/irq-gic-v3-its-platform-msi.c |  3 ++-
>  include/linux/acpi_iort.h                     |  5 +++++
>  3 files changed, 31 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 83cd59d..fb95ceb 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -468,6 +468,30 @@ u32 iort_msi_map_rid(struct device *dev, u32 req_id)
>  }
>  
>  /**
> + * iort_pmsi_get_dev_id() - Get the device id for a device
> + * @dev: The device for which the mapping is to be done.
> + * @dev_id: The device ID found.
> + *
> + * Returns: 0 for successful find a dev id, -ENODEV on error
> + */
> +int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
> +{
> +	int i;
> +	struct acpi_iort_node *node;
> +
> +	node = iort_find_dev_node(dev);
> +	if (!node)
> +		return -ENODEV;

I think that when specs are updated so that we can enable SMMU MSIs we
shall have to find a way to get the acpi_iort_node for a device that is
not a named component here (ie SMMU), I reckon we can use the
fwnode_handle but I have to have a deeper look.

This does not affect the patchset in its current form, just scanning
the code to make sure we will be able to support SMMU MSIs too when
time comes.

Thanks,
Lorenzo

> +
> +	for (i = 0; i < node->mapping_count; i++) {
> +		if (iort_node_map_platform_id(node, dev_id, IORT_MSI_TYPE, i))
> +			return 0;
> +	}
> +
> +	return -ENODEV;
> +}
> +
> +/**
>   * iort_dev_find_its_id() - Find the ITS identifier for a device
>   * @dev: The device.
>   * @req_id: Device's requester ID
> diff --git a/drivers/irqchip/irq-gic-v3-its-platform-msi.c b/drivers/irqchip/irq-gic-v3-its-platform-msi.c
> index e4ba9f4..e801fc0 100644
> --- a/drivers/irqchip/irq-gic-v3-its-platform-msi.c
> +++ b/drivers/irqchip/irq-gic-v3-its-platform-msi.c
> @@ -57,7 +57,8 @@ static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
>  
>  	msi_info = msi_get_domain_info(domain->parent);
>  
> -	ret = of_pmsi_get_dev_id(domain, dev, &dev_id);
> +	ret = dev->of_node ? of_pmsi_get_dev_id(domain, dev, &dev_id) :
> +		iort_pmsi_get_dev_id(dev, &dev_id);
>  	if (ret)
>  		return ret;
>  
> diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
> index 77e0809..d074c77 100644
> --- a/include/linux/acpi_iort.h
> +++ b/include/linux/acpi_iort.h
> @@ -34,6 +34,7 @@
>  bool iort_node_match(u8 type);
>  u32 iort_msi_map_rid(struct device *dev, u32 req_id);
>  struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id);
> +int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id);
>  /* IOMMU interface */
>  void iort_set_dma_mask(struct device *dev);
>  const struct iommu_ops *iort_iommu_configure(struct device *dev);
> @@ -45,6 +46,10 @@ static inline u32 iort_msi_map_rid(struct device *dev, u32 req_id)
>  static inline struct irq_domain *iort_get_device_domain(struct device *dev,
>  							u32 req_id)
>  { return NULL; }
> +
> +static inline int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
> +{ return -ENODEV; }
> +
>  /* IOMMU interface */
>  static inline void iort_set_dma_mask(struct device *dev) { }
>  static inline
> -- 
> 1.7.12.4
>