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.c...@rock-chips.com>
Reviewed-by: Tomasz Figa <tf...@chromium.org>
Reviewed-by: Robin Murphy <robin.mur...@arm.com>
---

Changes in v8: None
Changes in v7: None
Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2: None

 drivers/iommu/rockchip-iommu.c | 85 ++++++++++++------------------------------
 1 file changed, 24 insertions(+), 61 deletions(-)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 50ab9fd4eeb0..7970d21b9858 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -79,7 +79,6 @@
 
 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 */
@@ -105,12 +104,14 @@ 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)
@@ -625,7 +626,6 @@ 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;
@@ -643,9 +643,9 @@ 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);
        }
@@ -911,29 +911,20 @@ static void rk_iommu_detach_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.
@@ -944,11 +935,10 @@ 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;
        }
 
@@ -969,8 +959,6 @@ 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;
 }
@@ -987,20 +975,18 @@ 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)
@@ -1123,30 +1109,6 @@ 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;
@@ -1220,6 +1182,14 @@ 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;
+
        return 0;
 err_remove_sysfs:
        iommu_device_sysfs_remove(&iommu->iommu);
@@ -1276,14 +1246,7 @@ static int __init rk_iommu_init(void)
        if (ret)
                return 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 platform_driver_register(&rk_iommu_driver);
 }
 subsys_initcall(rk_iommu_init);
 
-- 
2.11.0


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