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From: Randy Dunlap <rdunlap@infradead.org>
To: Jianyu Zhan <nasa4836@gmail.com>,
	jiang.liu@linux.intel.com, marc.zyngier@arm.com, corbet@lwn.net,
	grant.likely@secretlab.ca
Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Documentation/IRQ-domain.txt: Document irq_domain_create_{linear, tree}
Date: Sat, 26 Mar 2016 10:04:39 -0700	[thread overview]
Message-ID: <56F6C127.3020405@infradead.org> (raw)
In-Reply-To: <1458997642-4241-1-git-send-email-nasa4836@gmail.com>

On 03/26/16 06:07, Jianyu Zhan wrote:
> They have the same functionalities as irq_domain_add_{linear, tree},
> except fro accepting different first argument.
> 
> Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
> ---
>  Documentation/IRQ-domain.txt | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/Documentation/IRQ-domain.txt b/Documentation/IRQ-domain.txt
> index 8d990bd..89dda22 100644
> --- a/Documentation/IRQ-domain.txt
> +++ b/Documentation/IRQ-domain.txt
> @@ -70,6 +70,7 @@ of the reverse map types are described below:
>  
>  ==== Linear ====
>  irq_domain_add_linear()
> +irq_domain_create_linear()
>  
>  The linear reverse map maintains a fixed size table indexed by the
>  hwirq number.  When a hwirq is mapped, an irq_desc is allocated for
> @@ -81,10 +82,16 @@ map are fixed time lookup for IRQ numbers, and irq_descs are only
>  allocated for in-use IRQs.  The disadvantage is that the table must be
>  as large as the largest possible hwirq number.
>  
> +irq_domain_add_linear() and irq_domain_create_linear() are functionally
> +equivalent, except for the first argument is different - the former
> +accepts an Open Firmware specific 'struct device_node', while the latter
> +accepts a more general abstration 'struct fwnode_handle'.

                          abstraction

> +
>  The majority of drivers should use the linear map.
>  
>  ==== Tree ====
>  irq_domain_add_tree()
> +irq_domain_create_tree()
>  
>  The irq_domain maintains a radix tree map from hwirq numbers to Linux
>  IRQs.  When an hwirq is mapped, an irq_desc is allocated and the
> @@ -95,6 +102,11 @@ since it doesn't need to allocate a table as large as the largest
>  hwirq number.  The disadvantage is that hwirq to IRQ number lookup is
>  dependent on how many entries are in the table.
>  
> +irq_domain_add_tree() and irq_domain_create_tree() are functionally
> +equivalent, except for the first argument is different - the former
> +accepts an Open Firmware specific 'struct device_node', while the latter
> +accepts a more general abstration 'struct fwnode_handle'.

ditto

> +
>  Very few drivers should need this mapping.
>  
>  ==== No Map ===-
> 


-- 
~Randy

  reply	other threads:[~2016-03-26 17:04 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-26 13:07 [PATCH] Documentation/IRQ-domain.txt: Document irq_domain_create_{linear, tree} Jianyu Zhan
2016-03-26 17:04 ` Randy Dunlap [this message]
2016-03-27  3:51   ` Jianyu Zhan
2016-03-29 10:15     ` Marc Zyngier
2016-03-31  6:33     ` Jonathan Corbet

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