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 <jroedel@xxxxxxx>
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 <jroedel@xxxxxxx>
---
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
--
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