iommu/mediatek: Merge 2 M4U HWs into one iommu domain

In theory, If there are 2 M4U HWs, there should be 2 IOMMU domains.
But one IOMMU domain(4GB iova range) is enough for us currently,
It's unnecessary to maintain 2 pagetables.

Besides, This patch can simplify our consumer code largely. They don't
need map a iova range from one domain into another, They can share the
iova address easily.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index df23e020133645469d5774812c7d16b3c15549d3..1503dfaa0a6980e92e3f9fda47ee328c3cf01cc2 100644 (file)
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -114,6 +114,27 @@ struct mtk_iommu_domain {
 
 static struct iommu_ops mtk_iommu_ops;
 
+static LIST_HEAD(m4ulist);     /* List all the M4U HWs */
+
+#define for_each_m4u(data)     list_for_each_entry(data, &m4ulist, list)
+
+/*
+ * There may be 1 or 2 M4U HWs, But we always expect they are in the same domain
+ * for the performance.
+ *
+ * Here always return the mtk_iommu_data of the first probed M4U where the
+ * iommu domain information is recorded.
+ */
+static struct mtk_iommu_data *mtk_iommu_get_m4u_data(void)
+{
+       struct mtk_iommu_data *data;
+
+       for_each_m4u(data)
+               return data;
+
+       return NULL;
+}
+
 static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
 {
        return container_of(dom, struct mtk_iommu_domain, domain);
@@ -123,9 +144,12 @@ static void mtk_iommu_tlb_flush_all(void *cookie)
 {
        struct mtk_iommu_data *data = cookie;
 
-       writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, data->base + REG_MMU_INV_SEL);
-       writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE);
-       wmb(); /* Make sure the tlb flush all done */
+       for_each_m4u(data) {
+               writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
+                              data->base + REG_MMU_INV_SEL);
+               writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE);
+               wmb(); /* Make sure the tlb flush all done */
+       }
 }
 
 static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size,
@@ -134,12 +158,17 @@ static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size,
 {
        struct mtk_iommu_data *data = cookie;
 
-       writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, data->base + REG_MMU_INV_SEL);
+       for_each_m4u(data) {
+               writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
+                              data->base + REG_MMU_INV_SEL);
 
-       writel_relaxed(iova, data->base + REG_MMU_INVLD_START_A);
-       writel_relaxed(iova + size - 1, data->base + REG_MMU_INVLD_END_A);
-       writel_relaxed(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
-       data->tlb_flush_active = true;
+               writel_relaxed(iova, data->base + REG_MMU_INVLD_START_A);
+               writel_relaxed(iova + size - 1,
+                              data->base + REG_MMU_INVLD_END_A);
+               writel_relaxed(F_MMU_INV_RANGE,
+                              data->base + REG_MMU_INVALIDATE);
+               data->tlb_flush_active = true;
+       }
 }
 
 static void mtk_iommu_tlb_sync(void *cookie)
@@ -148,20 +177,22 @@ static void mtk_iommu_tlb_sync(void *cookie)
        int ret;
        u32 tmp;
 
-       /* Avoid timing out if there's nothing to wait for */
-       if (!data->tlb_flush_active)
-               return;
+       for_each_m4u(data) {
+               /* Avoid timing out if there's nothing to wait for */
+               if (!data->tlb_flush_active)
+                       return;
 
-       ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE, tmp,
-                                       tmp != 0, 10, 100000);
-       if (ret) {
-               dev_warn(data->dev,
-                        "Partial TLB flush timed out, falling back to full flush\n");
-               mtk_iommu_tlb_flush_all(cookie);
+               ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
+                                               tmp, tmp != 0, 10, 100000);
+               if (ret) {
+                       dev_warn(data->dev,
+                                "Partial TLB flush timed out, falling back to full flush\n");
+                       mtk_iommu_tlb_flush_all(cookie);
+               }
+               /* Clear the CPE status */
+               writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
+               data->tlb_flush_active = false;
        }
-       /* Clear the CPE status */
-       writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
-       data->tlb_flush_active = false;
 }
 
 static const struct iommu_gather_ops mtk_iommu_gather_ops = {
@@ -298,10 +329,11 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
                                   struct device *dev)
 {
        struct mtk_iommu_domain *dom = to_mtk_domain(domain);
-       struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
+       struct mtk_iommu_data *curdata = dev->iommu_fwspec->iommu_priv;
+       struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
        int ret;
 
-       if (!data)
+       if (!data || !curdata)
                return -ENODEV;
 
        if (!data->m4u_dom) {
@@ -313,7 +345,17 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
                }
        }
 
-       mtk_iommu_config(data, dev, true);
+       /*
+        * Update the pgtable base address register of another M4U HW with the
+        * existed pgtable if there are more than one M4U HW.
+        */
+       if (!curdata->m4u_dom) {
+               curdata->m4u_dom = data->m4u_dom;
+               writel(data->m4u_dom->cfg.arm_v7s_cfg.ttbr[0],
+                      curdata->base + REG_MMU_PT_BASE_ADDR);
+       }
+
+       mtk_iommu_config(curdata, dev, true);
        return 0;
 }
 
@@ -405,7 +447,7 @@ static void mtk_iommu_remove_device(struct device *dev)
 
 static struct iommu_group *mtk_iommu_device_group(struct device *dev)
 {
-       struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
+       struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
 
        if (!data)
                return ERR_PTR(-ENODEV);
@@ -604,6 +646,8 @@ static int mtk_iommu_probe(struct platform_device *pdev)
        if (ret)
                return ret;
 
+       list_add_tail(&data->list, &m4ulist);
+
        if (!iommu_present(&platform_bus_type))
                bus_set_iommu(&platform_bus_type, &mtk_iommu_ops);
 

diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
index 462e593b7d713128259872609fede13f7370c551..b4451a1c7c2f167060edac5dbe5ce53a99b21144 100644 (file)
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -57,6 +57,8 @@ struct mtk_iommu_data {
 
        struct iommu_device             iommu;
        enum mtk_iommu_plat             m4u_plat;
+
+       struct list_head                list;
 };
 
 static inline int compare_of(struct device *dev, void *data)