public inbox for linux-arm-kernel@lists.infradead.org 
 help / color / mirror / Atom feed
From: will.deacon@arm•com (Will Deacon)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 4/6] iommu/arm-smmu: implement generic DT bindings
Date: Tue, 19 Aug 2014 13:54:49 +0100	[thread overview]
Message-ID: <20140819125449.GN23128@arm.com> (raw)
In-Reply-To: <1407891099-24641-5-git-send-email-mitchelh@codeaurora.org>

[adding Rob, Mark, Arnd, Thierry and Hiroshi]

On Wed, Aug 13, 2014 at 01:51:37AM +0100, Mitchel Humpherys wrote:
> Generic IOMMU device tree bindings were recently added in
> ["devicetree: Add generic IOMMU device tree bindings"]. Implement the
> bindings in the ARM SMMU driver.
> 
> See Documentation/devicetree/bindings/iommu/iommu.txt for the bindings
> themselves.

Could you look at moving the parsing code into a separate file please (maybe
under lib/ ?). That way, other IOMMUs can use the same binding without the
boilerplate having to be rewritten each time.

> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 63c6707fad..22e25f3172 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -538,25 +538,32 @@ static int insert_smmu_master(struct arm_smmu_device *smmu,
>  	return 0;
>  }
>  
> +struct iommus_entry {
> +	struct list_head list;
> +	struct device_node *node;
> +	u16 streamids[MAX_MASTER_STREAMIDS];
> +	int num_sids;
> +};
> +
>  static int register_smmu_master(struct arm_smmu_device *smmu,
> -				struct device *dev,
> -				struct of_phandle_args *masterspec)
> +				struct iommus_entry *entry)
>  {
>  	int i;
>  	struct arm_smmu_master *master;
> +	struct device *dev = smmu->dev;
>  
> -	master = find_smmu_master(smmu, masterspec->np);
> +	master = find_smmu_master(smmu, entry->node);
>  	if (master) {
>  		dev_err(dev,
>  			"rejecting multiple registrations for master device %s\n",
> -			masterspec->np->name);
> +			entry->node->name);
>  		return -EBUSY;
>  	}
>  
> -	if (masterspec->args_count > MAX_MASTER_STREAMIDS) {
> +	if (entry->num_sids > MAX_MASTER_STREAMIDS) {
>  		dev_err(dev,
>  			"reached maximum number (%d) of stream IDs for master device %s\n",
> -			MAX_MASTER_STREAMIDS, masterspec->np->name);
> +			MAX_MASTER_STREAMIDS, entry->node->name);
>  		return -ENOSPC;
>  	}
>  
> @@ -564,15 +571,58 @@ static int register_smmu_master(struct arm_smmu_device *smmu,
>  	if (!master)
>  		return -ENOMEM;
>  
> -	master->of_node			= masterspec->np;
> -	master->cfg.num_streamids	= masterspec->args_count;
> +	master->of_node			= entry->node;
> +	master->cfg.num_streamids	= entry->num_sids;
>  
>  	for (i = 0; i < master->cfg.num_streamids; ++i)
> -		master->cfg.streamids[i] = masterspec->args[i];
> +		master->cfg.streamids[i] = entry->streamids[i];
>  
>  	return insert_smmu_master(smmu, master);
>  }
>  
> +static int arm_smmu_parse_iommus_properties(struct arm_smmu_device *smmu,
> +					int *num_masters)
> +{
> +	struct of_phandle_args iommuspec;
> +	struct device_node *dn;
> +
> +	for_each_node_with_property(dn, "iommus") {
> +		int arg_ind = 0;
> +		struct iommus_entry *entry, *n;
> +		LIST_HEAD(iommus);
> +
> +		while (!of_parse_phandle_with_args(dn, "iommus", "#iommu-cells",
> +							arg_ind, &iommuspec)) {

We need to check that the phandle does indeed point at one of our SMMUs
here, in case we have a system with multiple IOMMU types, all using the
generic binding.

> +			int i;
> +
> +			list_for_each_entry(entry, &iommus, list)
> +				if (entry->node == dn)
> +					break;

Oh, yuck, this is really nasty to parse...

> +			if (&entry->list == &iommus) {

Where is entry initialised the first time around?

> +				entry = devm_kzalloc(smmu->dev, sizeof(*entry),
> +						GFP_KERNEL);
> +				if (!entry)
> +					return -ENOMEM;

You need to of_node_put the guys you've got back from the phandle parsing
code.

> +				entry->node = dn;
> +				list_add(&entry->list, &iommus);
> +			}
> +			entry->num_sids = iommuspec.args_count;
> +			for (i = 0; i < entry->num_sids; ++i)
> +				entry->streamids[i] = iommuspec.args[i];
> +			arg_ind++;

Isn't this defined by #iommu-cells?

> +		}
> +
> +		list_for_each_entry_safe(entry, n, &iommus, list) {

Why the _safe variant? This is a local list, right?

Will

  parent reply	other threads:[~2014-08-19 12:54 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-13  0:51 [PATCH 0/6] iommu/arm-smmu: misc features, new DT bindings Mitchel Humpherys
2014-08-13  0:51 ` [PATCH 1/6] iommu/arm-smmu: add support for specifying clocks Mitchel Humpherys
2014-08-13 21:07   ` Mitchel Humpherys
2014-08-19 12:58   ` Will Deacon
2014-08-19 19:03     ` Olav Haugan
2014-08-26 14:27       ` Will Deacon
2014-09-10  1:29         ` Mitchel Humpherys
2014-09-10 18:27           ` Will Deacon
2014-09-10 19:09             ` Mitchel Humpherys
2014-09-15 18:38               ` Mitchel Humpherys
2014-08-19 19:28     ` Mitchel Humpherys
2014-08-13  0:51 ` [PATCH 2/6] iommu/arm-smmu: add support for specifying regulators Mitchel Humpherys
2014-08-13 21:17   ` Mitchel Humpherys
2014-08-19 13:00   ` Will Deacon
2014-08-13  0:51 ` [PATCH 3/6] iommu/arm-smmu: add support for iova_to_phys through ATS1PR Mitchel Humpherys
2014-08-19 12:44   ` Will Deacon
2014-08-19 18:12     ` Mitchel Humpherys
2014-08-26 13:54       ` Will Deacon
2014-09-01 16:15         ` Will Deacon
2014-08-13  0:51 ` [PATCH 4/6] iommu/arm-smmu: implement generic DT bindings Mitchel Humpherys
2014-08-13 16:53   ` Mitchel Humpherys
2014-08-19 12:54   ` Will Deacon [this message]
2014-08-19 15:54     ` Hiroshi Doyu
2014-08-20  3:18     ` Arnd Bergmann
2014-08-13  0:51 ` [PATCH 5/6] iommu/arm-smmu: support buggy implementations with invalidate-on-map Mitchel Humpherys
2014-11-12 18:26   ` Will Deacon
2014-11-12 18:58     ` Mitchel Humpherys
2014-11-13  9:48       ` Will Deacon
2014-11-14 23:08         ` Mitchel Humpherys
2014-08-13  0:51 ` [PATCH 6/6] iommu/arm-smmu: add .domain_{set, get}_attr for coherent walk control Mitchel Humpherys
2014-08-19 12:48   ` [PATCH 6/6] iommu/arm-smmu: add .domain_{set,get}_attr " Will Deacon
2014-08-19 19:19     ` [PATCH 6/6] iommu/arm-smmu: add .domain_{set, get}_attr " Mitchel Humpherys
2014-08-13 17:22 ` [PATCH 0/6] iommu/arm-smmu: misc features, new DT bindings Mitchel Humpherys
2014-08-15 17:25   ` Will Deacon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20140819125449.GN23128@arm.com \
    --to=will.deacon@arm$(echo .)com \
    --cc=linux-arm-kernel@lists$(echo .)infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox