Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754882AbcCWLrU (ORCPT ); Wed, 23 Mar 2016 07:47:20 -0400 Received: from 8bytes.org ([81.169.241.247]:56847 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752116AbcCWLrK (ORCPT ); Wed, 23 Mar 2016 07:47:10 -0400 Date: Wed, 23 Mar 2016 12:47:07 +0100 From: Joerg Roedel To: Rob Herring Cc: Grant Likely , Will Deacon , "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" , Linux IOMMU , "linux-kernel@vger.kernel.org" , Joerg Roedel Subject: [PATCH v2] iommu/arm-smmu: Make use of phandle iterators in device-tree device-tree parsing Message-ID: <20160323114707.GA17838@8bytes.org> References: <1458669509-7178-1-git-send-email-joro@8bytes.org> <1458669509-7178-7-git-send-email-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3610 Lines: 119 On Tue, Mar 22, 2016 at 01:38:06PM -0500, Rob Herring wrote: > > + struct of_phandle_iterator it; > > + struct arm_smmu_phandle_args masterspec; > > Isn't this a bit big to put on the stack being ~512 bytes? Yeah, you might be right. I havn't seen any problems booting with this being allocated on the stack, but to be on the safe side I changed the patch to allocate the masterspec with kmalloc, patch below. Joerg >From 85995d1edea7f61aae3c31e0fbd3258622d0b5ae Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Wed, 16 Mar 2016 17:10:10 +0100 Subject: [PATCH] iommu/arm-smmu: Make use of phandle iterators in device-tree parsing Remove the usage of of_parse_phandle_with_args() and replace it by the phandle-iterator implementation so that we can parse out all of the potentially present 128 stream-ids. Signed-off-by: Joerg Roedel --- drivers/iommu/arm-smmu.c | 41 +++++++++++++++++++++++++++++++++-------- 1 file changed, 33 insertions(+), 8 deletions(-) diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 59ee4b8..fa9b98c 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -48,7 +48,7 @@ #include "io-pgtable.h" /* Maximum number of stream IDs assigned to a single device */ -#define MAX_MASTER_STREAMIDS MAX_PHANDLE_ARGS +#define MAX_MASTER_STREAMIDS 128 /* Maximum number of context banks per SMMU */ #define ARM_SMMU_MAX_CBS 128 @@ -349,6 +349,12 @@ struct arm_smmu_domain { struct iommu_domain domain; }; +struct arm_smmu_phandle_args { + struct device_node *np; + int args_count; + uint32_t args[MAX_MASTER_STREAMIDS]; +}; + static struct iommu_ops arm_smmu_ops; static DEFINE_SPINLOCK(arm_smmu_devices_lock); @@ -458,7 +464,7 @@ static int insert_smmu_master(struct arm_smmu_device *smmu, static int register_smmu_master(struct arm_smmu_device *smmu, struct device *dev, - struct of_phandle_args *masterspec) + struct arm_smmu_phandle_args *masterspec) { int i; struct arm_smmu_master *master; @@ -1716,7 +1722,8 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev) struct arm_smmu_device *smmu; struct device *dev = &pdev->dev; struct rb_node *node; - struct of_phandle_args masterspec; + struct of_phandle_iterator it; + struct arm_smmu_phandle_args *masterspec; int num_irqs, i, err; smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL); @@ -1777,20 +1784,38 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev) i = 0; smmu->masters = RB_ROOT; - while (!of_parse_phandle_with_args(dev->of_node, "mmu-masters", - "#stream-id-cells", i, - &masterspec)) { - err = register_smmu_master(smmu, dev, &masterspec); + + err = -ENOMEM; + /* No need to zero the memory for masterspec */ + masterspec = kmalloc(sizeof(*masterspec), GFP_KERNEL); + if (!masterspec) + goto out_put_masters; + + of_for_each_phandle(&it, err, dev->of_node, + "mmu-masters", "#stream-id-cells", 0) { + int count = of_phandle_iterator_args(&it, masterspec->args, + MAX_MASTER_STREAMIDS); + masterspec->np = of_node_get(it.node); + masterspec->args_count = count; + + err = register_smmu_master(smmu, dev, masterspec); if (err) { dev_err(dev, "failed to add master %s\n", - masterspec.np->name); + masterspec->np->name); + kfree(masterspec); goto out_put_masters; } i++; } + + if (i == 0) + goto out_put_masters; + dev_notice(dev, "registered %d master devices\n", i); + kfree(masterspec); + parse_driver_options(smmu); if (smmu->version > ARM_SMMU_V1 && -- 2.4.3