[RFC/PATCH 9/9] iommu/ipmmu-vmsa: Use DT-based instantiation

Laurent Pinchart
2015-05-14T23:00:10Z

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
drivers/iommu/ipmmu-vmsa.c | 189 ++++++++++++++-------------------------------
1 file changed, 60 insertions(+), 129 deletions(-)

diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index 24a950091458..7fa2afb5d7d1 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -18,6 +18,8 @@
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
+#include <linux/of_iommu.h>
+#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/sizes.h>
#include <linux/slab.h>
@@ -30,7 +32,6 @@
struct ipmmu_vmsa_device {
struct device *dev;
void __iomem *base;
- struct list_head list;

unsigned int num_utlbs;

@@ -54,9 +55,6 @@ struct ipmmu_vmsa_archdata {
unsigned int num_utlbs;
};

-static DEFINE_SPINLOCK(ipmmu_devices_lock);
-static LIST_HEAD(ipmmu_devices);
-
static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
{
return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
@@ -578,110 +576,81 @@ static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
return domain->iop->iova_to_phys(domain->iop, iova);
}

-static int ipmmu_find_utlbs(struct ipmmu_vmsa_device *mmu, struct device *dev,
- unsigned int *utlbs, unsigned int num_utlbs)
+static void ipmmu_remove_device(struct device *dev)
{
- unsigned int i;
-
- for (i = 0; i < num_utlbs; ++i) {
- struct of_phandle_args args;
- int ret;
-
- ret = of_parse_phandle_with_args(dev->of_node, "iommus",
- "#iommu-cells", i, &args);
- if (ret < 0)
- return ret;
+ struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;

- of_node_put(args.np);
+ if (!archdata)
+ return;

- if (args.np != mmu->dev->of_node || args.args_count != 1)
- return -EINVAL;
+ arm_iommu_detach_device(dev);
+ iommu_group_remove_device(dev);

- utlbs[i] = args.args[0];
- }
+ kfree(archdata->utlbs);
+ kfree(archdata);

- return 0;
+ dev->archdata.iommu = NULL;
}

-static int ipmmu_add_device(struct device *dev)
+static int ipmmu_of_xlate(struct device *dev, struct of_phandle_args *args)
{
struct ipmmu_vmsa_archdata *archdata;
struct ipmmu_vmsa_device *mmu;
- struct iommu_group *group = NULL;
+ struct platform_device *pdev;
+ unsigned int num_utlbs;
unsigned int *utlbs;
- unsigned int i;
- int num_utlbs;
- int ret = -ENODEV;
-
- if (dev->archdata.iommu) {
- dev_warn(dev, "IOMMU driver already assigned to device %s\n",
- dev_name(dev));
- return -EINVAL;
- }
+ unsigned int utlb;
+ int ret;

/* Find the master corresponding to the device. */
-
- num_utlbs = of_count_phandle_with_args(dev->of_node, "iommus",
- "#iommu-cells");
- if (num_utlbs < 0)
+ pdev = of_find_device_by_node(args->np);
+ if (!pdev) {
+ dev_dbg(dev, "%s: ipmmu pdev not found\n", __func__);
return -ENODEV;
-
- utlbs = kcalloc(num_utlbs, sizeof(*utlbs), GFP_KERNEL);
- if (!utlbs)
- return -ENOMEM;
-
- spin_lock(&ipmmu_devices_lock);
-
- list_for_each_entry(mmu, &ipmmu_devices, list) {
- ret = ipmmu_find_utlbs(mmu, dev, utlbs, num_utlbs);
- if (!ret) {
- /*
- * TODO Take a reference to the MMU to protect
- * against device removal.
- */
- break;
- }
}

- spin_unlock(&ipmmu_devices_lock);
-
- if (ret < 0)
+ mmu = platform_get_drvdata(pdev);
+ if (!mmu) {
+ dev_dbg(dev, "%s: ipmmu not found\n", __func__);
return -ENODEV;
-
- for (i = 0; i < num_utlbs; ++i) {
- if (utlbs[i] >= mmu->num_utlbs) {
- ret = -EINVAL;
- goto error;
- }
}

- /* Create a device group and add the device to it. */
- group = iommu_group_alloc();
- if (IS_ERR(group)) {
- dev_err(dev, "Failed to allocate IOMMU group\n");
- ret = PTR_ERR(group);
- goto error;
+ /* Allocate arch data if not already done. */
+ if (!dev->archdata.iommu) {
+ dev->archdata.iommu = kzalloc(sizeof(*archdata), GFP_KERNEL);
+ if (!dev->archdata.iommu)
+ return -ENOMEM;
}

- ret = iommu_group_add_device(group, dev);
- iommu_group_put(group);
+ archdata = dev->archdata.iommu;
+ archdata->mmu = mmu;

- if (ret < 0) {
- dev_err(dev, "Failed to add device to IPMMU group\n");
- group = NULL;
- goto error;
+ /*
+ * We don't support handling a device through different IOMMU
+ * instances.
+ */
+ if (archdata->mmu && archdata->mmu != mmu) {
+ dev_warn(dev, "IOMMU driver already assigned to device %s\n",
+ dev_name(dev));
+ return -EINVAL;
}

- archdata = kzalloc(sizeof(*archdata), GFP_KERNEL);
- if (!archdata) {
- ret = -ENOMEM;
- goto error;
+ /* Validate and store the microTLB number. */
+ utlb = args->args[0];
+ if (utlb >= mmu->num_utlbs) {
+ dev_dbg(dev, "%s: invalid utlb %u\n", __func__, utlb);
+ return -EINVAL;
}

- archdata->mmu = mmu;
+ num_utlbs = archdata->num_utlbs + 1;
+ utlbs = krealloc(archdata->utlbs, num_utlbs * sizeof(*utlbs),
+ GFP_KERNEL);
+ if (utlbs == NULL)
+ return -ENOMEM;
+ utlbs[archdata->num_utlbs] = utlb;
+
archdata->utlbs = utlbs;
archdata->num_utlbs = num_utlbs;
- dev->archdata.iommu = archdata;

/*
* Create the ARM mapping, used by the ARM DMA mapping core to allocate
@@ -699,50 +668,27 @@ static int ipmmu_add_device(struct device *dev)
SZ_1G, SZ_2G);
if (IS_ERR(mapping)) {
dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
- ret = PTR_ERR(mapping);
- goto error;
+ return PTR_ERR(mapping);
}

mmu->mapping = mapping;
}

- /* Attach the ARM VA mapping to the device. */
+ /*
+ * Detach the device from the default ARM VA mapping and attach it to
+ * our private mapping.
+ */
+ arm_iommu_detach_device(dev);
ret = arm_iommu_attach_device(dev, mmu->mapping);
if (ret < 0) {
dev_err(dev, "Failed to attach device to VA mapping\n");
- goto error;
+ return ret;
}

return 0;
-
-error:
- arm_iommu_release_mapping(mmu->mapping);
-
- kfree(dev->archdata.iommu);
- kfree(utlbs);
-
- dev->archdata.iommu = NULL;
-
- if (!IS_ERR_OR_NULL(group))
- iommu_group_remove_device(dev);
-
- return ret;
}

-static void ipmmu_remove_device(struct device *dev)
-{
- struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
-
- arm_iommu_detach_device(dev);
- iommu_group_remove_device(dev);
-
- kfree(archdata->utlbs);
- kfree(archdata);
-
- dev->archdata.iommu = NULL;
-}
-
-static const struct iommu_ops ipmmu_ops = {
+static struct iommu_ops ipmmu_ops = {
.domain_alloc = ipmmu_domain_alloc,
.domain_free = ipmmu_domain_free,
.attach_dev = ipmmu_attach_device,
@@ -751,8 +697,8 @@ static const struct iommu_ops ipmmu_ops = {
.unmap = ipmmu_unmap,
.map_sg = default_iommu_map_sg,
.iova_to_phys = ipmmu_iova_to_phys,
- .add_device = ipmmu_add_device,
.remove_device = ipmmu_remove_device,
+ .of_xlate = ipmmu_of_xlate,
.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
};

@@ -831,10 +777,7 @@ static int ipmmu_probe(struct platform_device *pdev)
* ipmmu_init() after the probe function returns.
*/

- spin_lock(&ipmmu_devices_lock);
- list_add(&mmu->list, &ipmmu_devices);
- spin_unlock(&ipmmu_devices_lock);
-
+ of_iommu_set_ops(mmu->dev->of_node, &ipmmu_ops);
platform_set_drvdata(pdev, mmu);

return 0;
@@ -844,10 +787,6 @@ static int ipmmu_remove(struct platform_device *pdev)
{
struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);

- spin_lock(&ipmmu_devices_lock);
- list_del(&mmu->list);
- spin_unlock(&ipmmu_devices_lock);
-
arm_iommu_release_mapping(mmu->mapping);

ipmmu_device_reset(mmu);
@@ -883,14 +822,6 @@ static int __init ipmmu_init(void)
return 0;
}

-static void __exit ipmmu_exit(void)
-{
- return platform_driver_unregister(&ipmmu_driver);
-}
-
subsys_initcall(ipmmu_init);
-module_exit(ipmmu_exit);

-MODULE_DESCRIPTION("IOMMU API for Renesas VMSA-compatible IPMMU");
-MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
-MODULE_LICENSE("GPL v2");
+IOMMU_OF_DECLARE(ipmmu_vmsa_of, "renesas,ipmmu-vmsa", NULL);
--
2.3.6