Re: [PATCH v6 05/14] ACPI: platform-msi: retrieve dev id from IORT

From: Tomasz Nowicki <tn@semihalf.com>
To: Hanjun Guo <hanjun.guo@linaro.org>,
	Marc Zyngier <marc.zyngier@arm.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linuxarm@huawei.com,
	Thomas Gleixner <tglx@linutronix.de>,
	Greg KH <gregkh@linuxfoundation.org>,
	Ma Jun <majun258@huawei.com>,
	Kefeng Wang <wangkefeng.wang@huawei.com>,
	Agustin Vega-Frias <agustinv@codeaurora.org>,
	Sinan Kaya <okaya@codeaurora.org>,
	charles.garcia-tobin@arm.com, huxinwei@huawei.com,
	yimin@huawei.com, Jon Masters <jcm@redhat.com>
Subject: Re: [PATCH v6 05/14] ACPI: platform-msi: retrieve dev id from IORT
Date: Tue, 3 Jan 2017 10:37:46 +0100	[thread overview]
Message-ID: <4ab6a7e3-7aa3-367d-a333-effb24399fd5@semihalf.com> (raw)
In-Reply-To: <13cb0c87-e1c0-c4d6-4793-a3edd20944dc@semihalf.com>

On 03.01.2017 09:43, Tomasz Nowicki wrote:
> On 02.01.2017 14:31, Hanjun Guo wrote:
>> For devices connecting to ITS, it needs dev id to identify
>> itself, and this dev id is represented in the IORT table in
>> named componant node [1] for platform devices, so in this
>> patch we will scan the IORT to retrieve device's dev id.
>>
>> Introduce iort_pmsi_get_dev_id() with pointer dev passed
>> in for that purpose.
>>
>> [1]:
>> https://static.docs.arm.com/den0049/b/DEN0049B_IO_Remapping_Table.pdf
>>
>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
>> Tested-by: Sinan Kaya <okaya@codeaurora.org>
>> Tested-by: Majun <majun258@huawei.com>
>> Tested-by: Xinwei Kong <kong.kongxinwei@hisilicon.com>
>> Cc: Marc Zyngier <marc.zyngier@arm.com>
>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> Cc: Tomasz Nowicki <tn@semihalf.com>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> ---
>>  drivers/acpi/arm64/iort.c                     | 26
>> ++++++++++++++++++++++++++
>>  drivers/irqchip/irq-gic-v3-its-platform-msi.c |  4 +++-
>>  include/linux/acpi_iort.h                     |  8 ++++++++
>>  3 files changed, 37 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
>> index 174e983..ab7bae7 100644
>> --- a/drivers/acpi/arm64/iort.c
>> +++ b/drivers/acpi/arm64/iort.c
>> @@ -444,6 +444,32 @@ 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, errors otherwise
>> + */
>> +int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
>> +{
>> +    struct acpi_iort_node *node;
>> +
>> +    if (!iort_table)
>> +        return -ENODEV;
>> +
>> +    node = iort_find_dev_node(dev);
>> +    if (!node) {
>> +        dev_err(dev, "can't find related IORT node\n");
>> +        return -ENODEV;
>> +    }
>> +
>> +    if(!iort_node_get_id(node, dev_id, IORT_MSI_TYPE, 0))
>> +        return -ENODEV;
>> +
>> +    return 0;
>> +}
>> +
>> +/**
> Giving that you are extending this to NC->
> SMMU->ITS case in later patch, we can use existing helpers from iort.c,
> like that:
>
> +/**
> + * 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, errors otherwise
> + */
> +int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
> +{
> +    struct acpi_iort_node *node;
> +
> +    node = iort_find_dev_node(dev);
> +    if (!node)
> +        return -ENODEV;
> +
> +    if (!iort_node_map_rid(node, 0, dev_id, IORT_MSI_TYPE))
> +        return -ENODEV;
> +
> +    return 0;
> +}
>
> Correct me if I am wrong.
>

"0" as rid_in for iort_node_map_rid() isn't good idea, sorry...

Tomasz