iommu/arm-smmu: Streamline SMMU data lookups

Simplify things somewhat by stashing our arm_smmu_device instance in
drvdata, so that it's readily available to our driver model callbacks.
Then we can excise the private list entirely, since the driver core
already has a perfectly good list of SMMU devices we can use in the one
instance we actually need to. Finally, make a further modest code saving
with the relatively new of_device_get_match_data() helper.

Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 11 insertions, 33 deletions

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 2023a77015a0..b6e26dba2dec 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -41,6 +41,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_device.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
@@ -370,8 +371,6 @@ struct arm_smmu_device {
         u32                             num_context_irqs;
         unsigned int                    *irqs;
 
-        struct list_head                list;
-
         u32                             cavium_id_base; /* Specific to Cavium */
 };
 
@@ -409,9 +408,6 @@ struct arm_smmu_domain {
         struct iommu_domain             domain;
 };
 
-static DEFINE_SPINLOCK(arm_smmu_devices_lock);
-static LIST_HEAD(arm_smmu_devices);
-
 struct arm_smmu_option_prop {
         u32 opt;
         const char *prop;
@@ -478,6 +474,8 @@ static int __find_legacy_master_phandle(struct device *dev, void *data)
         return err == -ENOENT ? 0 : err;
 }
 
+static struct platform_driver arm_smmu_driver;
+
 static int arm_smmu_register_legacy_master(struct device *dev)
 {
         struct arm_smmu_device *smmu;
@@ -495,19 +493,16 @@ static int arm_smmu_register_legacy_master(struct device *dev)
         }
 
         it.node = np;
-        spin_lock(&arm_smmu_devices_lock);
-        list_for_each_entry(smmu, &arm_smmu_devices, list) {
-                err = __find_legacy_master_phandle(smmu->dev, &data);
-                if (err)
-                        break;
-        }
-        spin_unlock(&arm_smmu_devices_lock);
+        err = driver_for_each_device(&arm_smmu_driver.driver, NULL, &data,
+                                     __find_legacy_master_phandle);
         of_node_put(np);
         if (err == 0)
                 return -ENODEV;
         if (err < 0)
                 return err;
 
+        smmu = dev_get_drvdata(data);
+
         if (it.cur_count > MAX_MASTER_STREAMIDS) {
                 dev_err(smmu->dev,
                         "reached maximum number (%d) of stream IDs for master device %s\n",
@@ -1816,7 +1811,6 @@ MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
 
 static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 {
-        const struct of_device_id *of_id;
         const struct arm_smmu_match_data *data;
         struct resource *res;
         struct arm_smmu_device *smmu;
@@ -1830,8 +1824,7 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
         }
         smmu->dev = dev;
 
-        of_id = of_match_node(arm_smmu_of_match, dev->of_node);
-        data = of_id->data;
+        data = of_device_get_match_data(dev);
         smmu->version = data->version;
         smmu->model = data->model;
 
@@ -1904,35 +1897,20 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
                 }
         }
 
-        INIT_LIST_HEAD(&smmu->list);
-        spin_lock(&arm_smmu_devices_lock);
-        list_add(&smmu->list, &arm_smmu_devices);
-        spin_unlock(&arm_smmu_devices_lock);
-
+        platform_set_drvdata(pdev, smmu);
         arm_smmu_device_reset(smmu);
         return 0;
 }
 
 static int arm_smmu_device_remove(struct platform_device *pdev)
 {
-        struct device *dev = &pdev->dev;
-        struct arm_smmu_device *curr, *smmu = NULL;
-
-        spin_lock(&arm_smmu_devices_lock);
-        list_for_each_entry(curr, &arm_smmu_devices, list) {
-                if (curr->dev == dev) {
-                        smmu = curr;
-                        list_del(&smmu->list);
-                        break;
-                }
-        }
-        spin_unlock(&arm_smmu_devices_lock);
+        struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
 
         if (!smmu)
                 return -ENODEV;
 
         if (!bitmap_empty(smmu->context_map, ARM_SMMU_MAX_CBS))
-                dev_err(dev, "removing device with active domains!\n");
+                dev_err(&pdev->dev, "removing device with active domains!\n");
 
         /* Turn the thing off */
         writel(sCR0_CLIENTPD, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);