[PATCH v2 10/13] iommu/rockchip: Use IOMMU device for dma mapping operations

Jeffy Chen
2018-01-16T13:25:37Z

Use the first registered IOMMU device for dma mapping operations, and
drop the domain platform device.

This is similar to exynos iommu driver.

Signed-off-by: Jeffy Chen <jeffy.chen-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
---

Changes in v2: None

drivers/iommu/rockchip-iommu.c | 91 +++++++++++-------------------------------
1 file changed, 24 insertions(+), 67 deletions(-)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index ea4df162108b..51e4f982c4a6 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -78,7 +78,6 @@

struct rk_iommu_domain {
struct list_head iommus;
- struct platform_device *pdev;
u32 *dt; /* page directory table */
dma_addr_t dt_dma;
spinlock_t iommus_lock; /* lock for iommus list */
@@ -100,12 +99,14 @@ struct rk_iommu {
struct iommu_domain *domain; /* domain to which iommu is attached */
};

+static struct device *dma_dev;
+
static inline void rk_table_flush(struct rk_iommu_domain *dom, dma_addr_t dma,
unsigned int count)
{
size_t size = count * sizeof(u32); /* count of u32 entry */

- dma_sync_single_for_device(&dom->pdev->dev, dma, size, DMA_TO_DEVICE);
+ dma_sync_single_for_device(dma_dev, dma, size, DMA_TO_DEVICE);
}

static struct rk_iommu_domain *to_rk_domain(struct iommu_domain *dom)
@@ -692,7 +693,6 @@ static void rk_iommu_zap_iova_first_last(struct rk_iommu_domain *rk_domain,
static u32 *rk_dte_get_page_table(struct rk_iommu_domain *rk_domain,
dma_addr_t iova)
{
- struct device *dev = &rk_domain->pdev->dev;
u32 *page_table, *dte_addr;
u32 dte_index, dte;
phys_addr_t pt_phys;
@@ -710,9 +710,9 @@ static u32 *rk_dte_get_page_table(struct rk_iommu_domain *rk_domain,
if (!page_table)
return ERR_PTR(-ENOMEM);

- pt_dma = dma_map_single(dev, page_table, SPAGE_SIZE, DMA_TO_DEVICE);
- if (dma_mapping_error(dev, pt_dma)) {
- dev_err(dev, "DMA mapping error while allocating page table\n");
+ pt_dma = dma_map_single(dma_dev, page_table, SPAGE_SIZE, DMA_TO_DEVICE);
+ if (dma_mapping_error(dma_dev, pt_dma)) {
+ dev_err(dma_dev, "DMA mapping error while allocating page table\n");
free_page((unsigned long)page_table);
return ERR_PTR(-ENOMEM);
}
@@ -987,29 +987,20 @@ static int rk_iommu_attach_device(struct iommu_domain *domain,
static struct iommu_domain *rk_iommu_domain_alloc(unsigned type)
{
struct rk_iommu_domain *rk_domain;
- struct platform_device *pdev;
- struct device *iommu_dev;

if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
return NULL;

- /* Register a pdev per domain, so DMA API can base on this *dev
- * even some virtual master doesn't have an iommu slave
- */
- pdev = platform_device_register_simple("rk_iommu_domain",
- PLATFORM_DEVID_AUTO, NULL, 0);
- if (IS_ERR(pdev))
+ if (!dma_dev)
return NULL;

- rk_domain = devm_kzalloc(&pdev->dev, sizeof(*rk_domain), GFP_KERNEL);
+ rk_domain = devm_kzalloc(dma_dev, sizeof(*rk_domain), GFP_KERNEL);
if (!rk_domain)
- goto err_unreg_pdev;
-
- rk_domain->pdev = pdev;
+ return NULL;

if (type == IOMMU_DOMAIN_DMA &&
iommu_get_dma_cookie(&rk_domain->domain))
- goto err_unreg_pdev;
+ return NULL;

/*
* rk32xx iommus use a 2 level pagetable.
@@ -1020,11 +1011,10 @@ static struct iommu_domain *rk_iommu_domain_alloc(unsigned type)
if (!rk_domain->dt)
goto err_put_cookie;

- iommu_dev = &pdev->dev;
- rk_domain->dt_dma = dma_map_single(iommu_dev, rk_domain->dt,
+ rk_domain->dt_dma = dma_map_single(dma_dev, rk_domain->dt,
SPAGE_SIZE, DMA_TO_DEVICE);
- if (dma_mapping_error(iommu_dev, rk_domain->dt_dma)) {
- dev_err(iommu_dev, "DMA map error for DT\n");
+ if (dma_mapping_error(dma_dev, rk_domain->dt_dma)) {
+ dev_err(dma_dev, "DMA map error for DT\n");
goto err_free_dt;
}

@@ -1045,8 +1035,6 @@ static struct iommu_domain *rk_iommu_domain_alloc(unsigned type)
err_put_cookie:
if (type == IOMMU_DOMAIN_DMA)
iommu_put_dma_cookie(&rk_domain->domain);
-err_unreg_pdev:
- platform_device_unregister(pdev);

return NULL;
}
@@ -1063,20 +1051,18 @@ static void rk_iommu_domain_free(struct iommu_domain *domain)
if (rk_dte_is_pt_valid(dte)) {
phys_addr_t pt_phys = rk_dte_pt_address(dte);
u32 *page_table = phys_to_virt(pt_phys);
- dma_unmap_single(&rk_domain->pdev->dev, pt_phys,
+ dma_unmap_single(dma_dev, pt_phys,
SPAGE_SIZE, DMA_TO_DEVICE);
free_page((unsigned long)page_table);
}
}

- dma_unmap_single(&rk_domain->pdev->dev, rk_domain->dt_dma,
+ dma_unmap_single(dma_dev, rk_domain->dt_dma,
SPAGE_SIZE, DMA_TO_DEVICE);
free_page((unsigned long)rk_domain->dt);

if (domain->type == IOMMU_DOMAIN_DMA)
iommu_put_dma_cookie(&rk_domain->domain);
-
- platform_device_unregister(rk_domain->pdev);
}

static bool rk_iommu_is_dev_iommu_master(struct device *dev)
@@ -1202,30 +1188,6 @@ static const struct iommu_ops rk_iommu_ops = {
.pgsize_bitmap = RK_IOMMU_PGSIZE_BITMAP,
};

-static int rk_iommu_domain_probe(struct platform_device *pdev)
-{
- struct device *dev = &pdev->dev;
-
- dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms), GFP_KERNEL);
- if (!dev->dma_parms)
- return -ENOMEM;
-
- /* Set dma_ops for dev, otherwise it would be dummy_dma_ops */
- arch_setup_dma_ops(dev, 0, DMA_BIT_MASK(32), NULL, false);
-
- dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
- dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
-
- return 0;
-}
-
-static struct platform_driver rk_iommu_domain_driver = {
- .probe = rk_iommu_domain_probe,
- .driver = {
- .name = "rk_iommu_domain",
- },
-};
-
static int rk_iommu_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -1288,6 +1250,14 @@ static int rk_iommu_probe(struct platform_device *pdev)
if (err)
goto err_remove_sysfs;

+ /*
+ * Use the first registered IOMMU device for domain to use with DMA
+ * API, since a domain might not physically correspond to a single
+ * IOMMU device..
+ */
+ if (!dma_dev)
+ dma_dev = &pdev->dev;
+
bus_set_iommu(&platform_bus_type, &rk_iommu_ops);

return 0;
@@ -1327,24 +1297,11 @@ static struct platform_driver rk_iommu_driver = {

static int __init rk_iommu_init(void)
{
- int ret;
-
- ret = platform_driver_register(&rk_iommu_domain_driver);
- if (ret)
- return ret;
-
- ret = platform_driver_register(&rk_iommu_driver);
- if (ret) {
- platform_driver_unregister(&rk_iommu_domain_driver);
- return ret;
- }
-
- return 0;
+ return platform_driver_register(&rk_iommu_driver);
}
static void __exit rk_iommu_exit(void)
{
platform_driver_unregister(&rk_iommu_driver);
- platform_driver_unregister(&rk_iommu_domain_driver);
}

subsys_initcall(rk_iommu_init);
--
2.11.0