When a device driver is registered, all constructs to handle System MMU
is prepared by bus notifier call.

Signed-off-by: Cho KyongHo <pullip....@samsung.com>
---
 drivers/iommu/exynos-iommu.c |  778 ++++++++++++++++++++++++++++++-----------
 1 files changed, 569 insertions(+), 209 deletions(-)

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index b151e51..51d43bb 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -27,6 +27,9 @@
 #include <linux/memblock.h>
 #include <linux/export.h>
 #include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/pm_domain.h>
+#include <linux/notifier.h>
 
 #include <asm/cacheflush.h>
 #include <asm/pgtable.h>
@@ -80,6 +83,14 @@
 #define CTRL_BLOCK     0x7
 #define CTRL_DISABLE   0x0
 
+#define CFG_LRU                0x1
+#define CFG_QOS(n)     ((n & 0xF) << 7)
+#define CFG_MASK       0x0150FFFF /* Selecting bit 0-15, 20, 22 and 24 */
+#define CFG_ACGEN      (1 << 24) /* System MMU 3.3 only */
+#define CFG_SYSSEL     (1 << 22) /* System MMU 3.2 only */
+#define CFG_FLPDCACHE  (1 << 20) /* System MMU 3.2+ only */
+#define CFG_SHAREABLE  (1 << 12) /* System MMU 3.x only */
+
 #define REG_MMU_CTRL           0x000
 #define REG_MMU_CFG            0x004
 #define REG_MMU_STATUS         0x008
@@ -96,6 +107,9 @@
 
 #define REG_MMU_VERSION                0x034
 
+#define MMU_MAJ_VER(reg)       (reg >> 28)
+#define MMU_MIN_VER(reg)       ((reg >> 21) & 0x7F)
+
 #define REG_PB0_SADDR          0x04C
 #define REG_PB0_EADDR          0x050
 #define REG_PB1_SADDR          0x054
@@ -126,16 +140,6 @@ enum exynos_sysmmu_inttype {
        SYSMMU_FAULTS_NUM
 };
 
-/*
- * @itype: type of fault.
- * @pgtable_base: the physical address of page table base. This is 0 if @itype
- *                is SYSMMU_BUSERROR.
- * @fault_addr: the device (virtual) address that the System MMU tried to
- *             translated. This is 0 if @itype is SYSMMU_BUSERROR.
- */
-typedef int (*sysmmu_fault_handler_t)(enum exynos_sysmmu_inttype itype,
-                       unsigned long pgtable_base, unsigned long fault_addr);
-
 static unsigned short fault_reg_offset[SYSMMU_FAULTS_NUM] = {
        REG_PAGE_FAULT_ADDR,
        REG_AR_FAULT_ADDR,
@@ -159,6 +163,14 @@ static char *sysmmu_fault_name[SYSMMU_FAULTS_NUM] = {
        "UNKNOWN FAULT"
 };
 
+struct exynos_iommu_client {
+       struct list_head node;  /* entry of exynos_iommu_domain.clients */
+       struct device *dev;
+       spinlock_t lock;
+       int num_sysmmu;
+       struct device *sysmmu[0];
+};
+
 struct exynos_iommu_domain {
        struct list_head clients; /* list of sysmmu_drvdata.node */
        unsigned long *pgtable; /* lv1 page table, 16KB */
@@ -170,13 +182,13 @@ struct exynos_iommu_domain {
 struct sysmmu_drvdata {
        struct list_head node; /* entry of exynos_iommu_domain.clients */
        struct device *sysmmu;  /* System MMU's device descriptor */
-       struct device *dev;     /* Owner of system MMU */
+       struct device *master;  /* Owner of system MMU */
        int nsfrs;
        struct clk *clk;
        int activations;
        spinlock_t lock;
        struct iommu_domain *domain;
-       sysmmu_fault_handler_t fault_handler;
+       bool runtime_active;
        unsigned long pgtable;
        void __iomem *sfrbases[0];
 };
@@ -200,6 +212,20 @@ static bool is_sysmmu_active(struct sysmmu_drvdata *data)
        return data->activations > 0;
 }
 
+static unsigned int __sysmmu_version(struct sysmmu_drvdata *data,
+                                       int idx, unsigned int *minor)
+{
+       unsigned int major;
+
+       major = readl(data->sfrbases[idx] + REG_MMU_VERSION);
+
+       if (minor)
+               *minor = MMU_MIN_VER(major);
+       major = MMU_MAJ_VER(major);
+
+       return major;
+}
+
 static void sysmmu_unblock(void __iomem *sfrbase)
 {
        __raw_writel(CTRL_ENABLE, sfrbase + REG_MMU_CTRL);
@@ -235,7 +261,6 @@ static void __sysmmu_tlb_invalidate_entry(void __iomem 
*sfrbase,
 static void __sysmmu_set_ptbase(void __iomem *sfrbase,
                                       unsigned long pgd)
 {
-       __raw_writel(0x1, sfrbase + REG_MMU_CFG); /* 16KB LV1, LRU */
        __raw_writel(pgd, sfrbase + REG_PT_BASE_ADDR);
 
        __sysmmu_tlb_invalidate(sfrbase);
@@ -292,34 +317,17 @@ finish:
        spin_unlock_irqrestore(&data->lock, flags);
 }
 
-static void __set_fault_handler(struct sysmmu_drvdata *data,
-                                       sysmmu_fault_handler_t handler)
-{
-       unsigned long flags;
-
-       spin_lock_irqsave(&data->lock, flags);
-       data->fault_handler = handler;
-       spin_unlock_irqrestore(&data->lock, flags);
-}
-
-void exynos_sysmmu_set_fault_handler(struct device *dev,
-                                       sysmmu_fault_handler_t handler)
-{
-       struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
-
-       __set_fault_handler(data, handler);
-}
-
-static int default_fault_handler(enum exynos_sysmmu_inttype itype,
-                    unsigned long pgtable_base, unsigned long fault_addr)
+static int show_fault_information(const char *name,
+               enum exynos_sysmmu_inttype itype,
+               unsigned long pgtable_base, unsigned long fault_addr)
 {
        unsigned long *ent;
 
        if ((itype >= SYSMMU_FAULTS_NUM) || (itype < SYSMMU_PAGEFAULT))
                itype = SYSMMU_FAULT_UNKNOWN;
 
-       pr_err("%s occurred at 0x%lx(Page table base: 0x%lx)\n",
-                       sysmmu_fault_name[itype], fault_addr, pgtable_base);
+       pr_err("%s occurred at 0x%lx by %s(Page table base: 0x%lx)\n",
+               sysmmu_fault_name[itype], fault_addr, name, pgtable_base);
 
        ent = section_entry(__va(pgtable_base), fault_addr);
        pr_err("\tLv1 entry: 0x%lx\n", *ent);
@@ -340,25 +348,34 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void 
*dev_id)
 {
        /* SYSMMU is in blocked when interrupt occurred. */
        struct sysmmu_drvdata *data = dev_id;
-       struct resource *irqres;
-       struct platform_device *pdev;
+       struct exynos_iommu_client *client = NULL;
+       struct resource *memres;
        enum exynos_sysmmu_inttype itype;
        unsigned long addr = -1;
-
        int i, ret = -ENOSYS;
 
-       spin_lock(&data->lock);
+       if (data->master)
+               client = data->master->archdata.iommu;
 
        WARN_ON(!is_sysmmu_active(data));
 
-       pdev = to_platform_device(data->sysmmu);
-       for (i = 0; i < (pdev->num_resources / 2); i++) {
-               irqres = platform_get_resource(pdev, IORESOURCE_IRQ, i);
-               if (irqres && ((int)irqres->start == irq))
+       for (i = 0; i < data->nsfrs; i++) {
+               struct resource *irqres;
+               irqres = platform_get_resource(to_platform_device(data->sysmmu),
+                                               IORESOURCE_IRQ, i);
+               if (irqres && ((int)irqres->start == irq)) {
+                       memres = platform_get_resource(
+                                       to_platform_device(data->sysmmu),
+                                       IORESOURCE_MEM, i);
                        break;
+               }
        }
 
-       if (i == pdev->num_resources) {
+       if (client)
+               spin_lock(&client->lock);
+       spin_lock(&data->lock);
+
+       if (i == data->nsfrs) {
                itype = SYSMMU_FAULT_UNKNOWN;
        } else {
                itype = (enum exynos_sysmmu_inttype)
@@ -371,197 +388,263 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void 
*dev_id)
        }
 
        if (data->domain)
-               ret = report_iommu_fault(data->domain, data->dev,
+               ret = report_iommu_fault(data->domain, data->master,
                                addr, itype);
 
-       if ((ret == -ENOSYS) && data->fault_handler) {
-               unsigned long base = data->pgtable;
-               if (itype != SYSMMU_FAULT_UNKNOWN)
-                       base = __raw_readl(
-                                       data->sfrbases[i] + REG_PT_BASE_ADDR);
-               ret = data->fault_handler(itype, base, addr);
-       }
-
        if (!ret && (itype != SYSMMU_FAULT_UNKNOWN))
                __raw_writel(1 << itype, data->sfrbases[i] + REG_INT_CLEAR);
-       else
-               dev_dbg(data->sysmmu, "%s is not handled.\n",
-                               sysmmu_fault_name[itype]);
+       else {
+               unsigned long ba = data->pgtable;
+               if (itype != SYSMMU_FAULT_UNKNOWN)
+                       ba = __raw_readl(data->sfrbases[i] + REG_PT_BASE_ADDR);
+               show_fault_information(dev_name(data->sysmmu),
+                                       itype, ba, addr);
+       }
 
        if (itype != SYSMMU_FAULT_UNKNOWN)
                sysmmu_unblock(data->sfrbases[i]);
 
        spin_unlock(&data->lock);
+       if (client)
+               spin_unlock(&client->lock);
 
        return IRQ_HANDLED;
 }
 
-static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data)
+static void __sysmmu_disable_nocount(struct sysmmu_drvdata *data)
 {
+               int i;
+
+               for (i = 0; i < data->nsfrs; i++) {
+                       __raw_writel(CTRL_DISABLE,
+                                    data->sfrbases[i] + REG_MMU_CTRL);
+                       __raw_writel(0, data->sfrbases[i] + REG_MMU_CFG);
+               }
+
+               clk_disable(data->clk);
+}
+
+static bool __sysmmu_disable(struct sysmmu_drvdata *data)
+{
+       bool disabled;
        unsigned long flags;
-       bool disabled = false;
-       int i;
 
        spin_lock_irqsave(&data->lock, flags);
 
-       if (!set_sysmmu_inactive(data))
-               goto finish;
+       disabled = set_sysmmu_inactive(data);
 
-       for (i = 0; i < data->nsfrs; i++)
-               __raw_writel(CTRL_DISABLE, data->sfrbases[i] + REG_MMU_CTRL);
+       if (disabled) {
+               data->pgtable = 0;
+               data->domain = NULL;
 
-       if (data->clk)
-               clk_disable(data->clk);
+               if (data->runtime_active)
+                       __sysmmu_disable_nocount(data);
 
-       disabled = true;
-       data->pgtable = 0;
-       data->domain = NULL;
-finish:
-       spin_unlock_irqrestore(&data->lock, flags);
-
-       if (disabled)
                dev_dbg(data->sysmmu, "Disabled\n");
-       else
-               dev_dbg(data->sysmmu, "%d times left to be disabled\n",
+       } else  {
+               dev_dbg(data->sysmmu, "%d times left to disable\n",
                                        data->activations);
+       }
+
+       spin_unlock_irqrestore(&data->lock, flags);
 
        return disabled;
 }
 
-/* __exynos_sysmmu_enable: Enables System MMU
- *
- * returns -error if an error occurred and System MMU is not enabled,
- * 0 if the System MMU has been just enabled and 1 if System MMU was already
- * enabled before.
- */
-static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
+
+static void __sysmmu_init_config(struct sysmmu_drvdata *data, int idx)
+{
+       unsigned long cfg = CFG_LRU;
+       int maj, min = 0;
+
+       maj = __sysmmu_version(data, idx, &min);
+       if (maj == 3) {
+               cfg |= CFG_SHAREABLE;
+               if (min > 1) {
+                       cfg |= CFG_FLPDCACHE;
+                       cfg |= (min == 2) ? CFG_SYSSEL : CFG_ACGEN;
+               }
+       }
+
+       cfg |= __raw_readl(data->sfrbases[idx] + REG_MMU_CFG) & ~CFG_MASK;
+       __raw_writel(cfg, data->sfrbases[idx] + REG_MMU_CFG);
+}
+
+static void __sysmmu_enable_nocount(struct sysmmu_drvdata *data)
+{
+       int i;
+
+       clk_enable(data->clk);
+
+       for (i = 0; i < data->nsfrs; i++) {
+               BUG_ON(__raw_readl(data->sfrbases[i] + REG_MMU_CTRL)
+                                                               & CTRL_ENABLE);
+
+               __sysmmu_init_config(data, i);
+
+               __sysmmu_set_ptbase(data->sfrbases[i], data->pgtable);
+
+               __raw_writel(CTRL_ENABLE, data->sfrbases[i] + REG_MMU_CTRL);
+       }
+}
+
+static int __sysmmu_enable(struct sysmmu_drvdata *data,
                        unsigned long pgtable, struct iommu_domain *domain)
 {
-       int i, ret = 0;
+       int ret = 0;
        unsigned long flags;
 
        spin_lock_irqsave(&data->lock, flags);
+       if (set_sysmmu_active(data)) {
+               data->pgtable = pgtable;
+               data->domain = domain;
 
-       if (!set_sysmmu_active(data)) {
-               if (WARN_ON(pgtable != data->pgtable)) {
-                       ret = -EBUSY;
-                       set_sysmmu_inactive(data);
-               } else {
-                       ret = 1;
-               }
+               if (data->runtime_active)
+                       __sysmmu_enable_nocount(data);
 
-               dev_dbg(data->sysmmu, "Already enabled\n");
-               goto finish;
+               dev_dbg(data->sysmmu, "Enabled\n");
+       } else {
+               ret = (pgtable == data->pgtable) ? 1 : -EBUSY;
+
+               dev_dbg(data->sysmmu, "already enabled\n");
        }
 
-       if (data->clk)
-               clk_enable(data->clk);
+       if (WARN_ON(ret < 0))
+               set_sysmmu_inactive(data); /* decrement count */
 
-       data->pgtable = pgtable;
+       spin_unlock_irqrestore(&data->lock, flags);
 
-       for (i = 0; i < data->nsfrs; i++) {
-               __sysmmu_set_ptbase(data->sfrbases[i], pgtable);
+       return ret;
+}
 
-               if ((readl(data->sfrbases[i] + REG_MMU_VERSION) >> 28) == 3) {
-                       /* System MMU version is 3.x */
-                       __raw_writel((1 << 12) | (2 << 28),
-                                       data->sfrbases[i] + REG_MMU_CFG);
-                       __sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 0);
-                       __sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 1);
-               }
+/* __exynos_sysmmu_enable: Enables System MMU
+ *
+ * returns -error if an error occurred and System MMU is not enabled,
+ * 0 if the System MMU has been just enabled and 1 if System MMU was already
+ * enabled before.
+ */
+static int __exynos_sysmmu_enable(struct device *dev, unsigned long pgtable,
+                                 struct iommu_domain *domain)
+{
+       int ret = 0;
+       unsigned long flags;
+       struct exynos_iommu_client *client = dev->archdata.iommu;
+       int i;
 
-               __raw_writel(CTRL_ENABLE, data->sfrbases[i] + REG_MMU_CTRL);
-       }
+       if (WARN_ON(!client))
+               return -ENODEV;
 
-       data->domain = domain;
+       spin_lock_irqsave(&client->lock, flags);
 
-       dev_dbg(data->sysmmu, "Enabled\n");
-finish:
-       spin_unlock_irqrestore(&data->lock, flags);
+       for (i = 0; i < client->num_sysmmu; i++) {
+               struct sysmmu_drvdata *data =
+                               dev_get_drvdata(client->sysmmu[i]);
+               ret = __sysmmu_enable(data, pgtable, domain);
+               if (ret < 0) {
+                       int j;
+                       for (j = 0; j < i; j++)
+                               __sysmmu_disable(data);
+                       break;
+               } else {
+                       data->master = dev;
+               }
+       }
+
+       spin_unlock_irqrestore(&client->lock, flags);
 
        return ret;
 }
 
 int exynos_sysmmu_enable(struct device *dev, unsigned long pgtable)
 {
-       struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
        int ret;
 
        BUG_ON(!memblock_is_memory(pgtable));
 
-       ret = pm_runtime_get_sync(data->sysmmu);
-       if (ret < 0) {
-               dev_dbg(data->sysmmu, "Failed to enable\n");
-               return ret;
-       }
-
-       ret = __exynos_sysmmu_enable(data, pgtable, NULL);
-       if (WARN_ON(ret < 0)) {
-               pm_runtime_put(data->sysmmu);
-               dev_err(data->sysmmu,
-                       "Already enabled with page table %#lx\n",
-                       data->pgtable);
-       } else {
-               data->dev = dev;
-       }
+       ret = __exynos_sysmmu_enable(dev, pgtable, NULL);
 
        return ret;
 }
 
 static bool exynos_sysmmu_disable(struct device *dev)
 {
-       struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
-       bool disabled;
+       unsigned long flags;
+       bool disabled = true;
+       struct exynos_iommu_client *client = dev->archdata.iommu;
+       int i;
+
+       if (WARN_ON(!client))
+               return true;
+
+       spin_lock_irqsave(&client->lock, flags);
+
+       /* Every call to __sysmmu_disable() must return same result */
+       for (i = 0; i < client->num_sysmmu; i++) {
+               struct sysmmu_drvdata *data =
+                               dev_get_drvdata(client->sysmmu[i]);
+               disabled = __sysmmu_disable(data);
+               if (disabled)
+                       data->master = NULL;
+       }
 
-       disabled = __exynos_sysmmu_disable(data);
-       pm_runtime_put(data->sysmmu);
+       spin_unlock_irqrestore(&client->lock, flags);
 
        return disabled;
 }
 
 static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova)
 {
-       unsigned long flags;
-       struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+       struct exynos_iommu_client *client = dev->archdata.iommu;
+       int i;
 
-       spin_lock_irqsave(&data->lock, flags);
+       for (i = 0; i < client->num_sysmmu; i++) {
+               unsigned long flags;
+               struct sysmmu_drvdata *data;
 
-       if (is_sysmmu_active(data)) {
-               int i;
-               for (i = 0; i < data->nsfrs; i++) {
-                       if (sysmmu_block(data->sfrbases[i])) {
+               data = dev_get_drvdata(client->sysmmu[i]);
+
+               spin_lock_irqsave(&data->lock, flags);
+               if (is_sysmmu_active(data) && data->runtime_active) {
+                       int i;
+                       for (i = 0; i < data->nsfrs; i++)
                                __sysmmu_tlb_invalidate_entry(
                                                data->sfrbases[i], iova);
-                               sysmmu_unblock(data->sfrbases[i]);
-                       }
+               } else {
+                       dev_dbg(dev,
+                               "disabled. Skipping TLB invalidation @ %#lx\n",
+                               iova);
                }
-       } else {
-               dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n");
+               spin_unlock_irqrestore(&data->lock, flags);
        }
-
-       spin_unlock_irqrestore(&data->lock, flags);
 }
 
 void exynos_sysmmu_tlb_invalidate(struct device *dev)
 {
-       unsigned long flags;
-       struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
-
-       spin_lock_irqsave(&data->lock, flags);
+       struct exynos_iommu_client *client = dev->archdata.iommu;
+       int i;
 
-       if (is_sysmmu_active(data)) {
-               int i;
-               for (i = 0; i < data->nsfrs; i++) {
-                       if (sysmmu_block(data->sfrbases[i])) {
-                               __sysmmu_tlb_invalidate(data->sfrbases[i]);
-                               sysmmu_unblock(data->sfrbases[i]);
+       for (i = 0; i < client->num_sysmmu; i++) {
+               unsigned long flags;
+               struct sysmmu_drvdata *data;
+
+               data = dev_get_drvdata(client->sysmmu[i]);
+
+               spin_lock_irqsave(&data->lock, flags);
+               if (is_sysmmu_active(data) &&
+                               data->runtime_active) {
+                       int i;
+                       for (i = 0; i < data->nsfrs; i++) {
+                               if (sysmmu_block(data->sfrbases[i])) {
+                                       __sysmmu_tlb_invalidate(
+                                                       data->sfrbases[i]);
+                                       sysmmu_unblock(data->sfrbases[i]);
+                               }
                        }
+               } else {
+                       dev_dbg(dev, "disabled. Skipping TLB invalidation\n");
                }
-       } else {
-               dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n");
+               spin_unlock_irqrestore(&data->lock, flags);
        }
-
-       spin_unlock_irqrestore(&data->lock, flags);
 }
 
 static int __init exynos_sysmmu_probe(struct platform_device *pdev)
@@ -622,8 +705,6 @@ static int __init exynos_sysmmu_probe(struct 
platform_device *pdev)
 
        pm_runtime_enable(dev);
 
-       __set_fault_handler(data, &default_fault_handler);
-
        data->sysmmu = dev;
        data->clk = devm_clk_get(dev, "sysmmu");
        if (IS_ERR(data->clk)) {
@@ -647,6 +728,8 @@ static int __init exynos_sysmmu_probe(struct 
platform_device *pdev)
                }
        }
 
+       data->runtime_active = !pm_runtime_enabled(dev);
+
        spin_lock_init(&data->lock);
        INIT_LIST_HEAD(&data->node);
 
@@ -656,6 +739,34 @@ static int __init exynos_sysmmu_probe(struct 
platform_device *pdev)
        return ret;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int sysmmu_suspend(struct device *dev)
+{
+       struct sysmmu_drvdata *data = dev_get_drvdata(dev);
+       unsigned long flags;
+       spin_lock_irqsave(&data->lock, flags);
+       if (is_sysmmu_active(data) &&
+               (!pm_runtime_enabled(dev) || data->runtime_active))
+               __sysmmu_disable_nocount(data);
+       spin_unlock_irqrestore(&data->lock, flags);
+       return 0;
+}
+
+static int sysmmu_resume(struct device *dev)
+{
+       struct sysmmu_drvdata *data = dev_get_drvdata(dev);
+       unsigned long flags;
+       spin_lock_irqsave(&data->lock, flags);
+       if (is_sysmmu_active(data) &&
+               (!pm_runtime_enabled(dev) || data->runtime_active))
+               __sysmmu_enable_nocount(data);
+       spin_unlock_irqrestore(&data->lock, flags);
+       return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(sysmmu_pm_ops, sysmmu_suspend, sysmmu_resume);
+
 #ifdef CONFIG_OF
 static struct of_device_id sysmmu_of_match[] __initconst = {
        { .compatible   = "samsung,exynos4210-sysmmu", },
@@ -668,6 +779,7 @@ static struct platform_driver exynos_sysmmu_driver 
__refdata = {
        .driver = {
                .owner          = THIS_MODULE,
                .name           = "exynos-sysmmu",
+               .pm             = &sysmmu_pm_ops,
                .of_match_table = of_match_ptr(sysmmu_of_match),
        }
 };
@@ -720,7 +832,7 @@ err_pgtable:
 static void exynos_iommu_domain_destroy(struct iommu_domain *domain)
 {
        struct exynos_iommu_domain *priv = domain->priv;
-       struct sysmmu_drvdata *data;
+       struct exynos_iommu_client *client;
        unsigned long flags;
        int i;
 
@@ -728,11 +840,14 @@ static void exynos_iommu_domain_destroy(struct 
iommu_domain *domain)
 
        spin_lock_irqsave(&priv->lock, flags);
 
-       list_for_each_entry(data, &priv->clients, node) {
-               while (!exynos_sysmmu_disable(data->dev))
+       list_for_each_entry(client, &priv->clients, node) {
+               while (!exynos_sysmmu_disable(client->dev))
                        ; /* until System MMU is actually disabled */
        }
 
+       while (!list_empty(&priv->clients))
+               list_del_init(priv->clients.next);
+
        spin_unlock_irqrestore(&priv->lock, flags);
 
        for (i = 0; i < NUM_LV1ENTRIES; i++)
@@ -749,41 +864,26 @@ static void exynos_iommu_domain_destroy(struct 
iommu_domain *domain)
 static int exynos_iommu_attach_device(struct iommu_domain *domain,
                                   struct device *dev)
 {
-       struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+       struct exynos_iommu_client *client = dev->archdata.iommu;
        struct exynos_iommu_domain *priv = domain->priv;
        unsigned long flags;
        int ret;
 
-       ret = pm_runtime_get_sync(data->sysmmu);
-       if (ret < 0)
-               return ret;
-
-       ret = 0;
-
        spin_lock_irqsave(&priv->lock, flags);
 
-       ret = __exynos_sysmmu_enable(data, __pa(priv->pgtable), domain);
-
-       if (ret == 0) {
-               /* 'data->node' must not be appeared in priv->clients */
-               BUG_ON(!list_empty(&data->node));
-               data->dev = dev;
-               list_add_tail(&data->node, &priv->clients);
-       }
+       ret = __exynos_sysmmu_enable(dev, __pa(priv->pgtable), domain);
+       if (ret == 0)
+               list_add_tail(&client->node, &priv->clients);
 
        spin_unlock_irqrestore(&priv->lock, flags);
 
-       if (ret < 0) {
+       if (ret < 0)
                dev_err(dev, "%s: Failed to attach IOMMU with pgtable %#lx\n",
                                __func__, __pa(priv->pgtable));
-               pm_runtime_put(data->sysmmu);
-       } else if (ret > 0) {
-               dev_dbg(dev, "%s: IOMMU with pgtable 0x%lx already attached\n",
-                                       __func__, __pa(priv->pgtable));
-       } else {
-               dev_dbg(dev, "%s: Attached new IOMMU with pgtable 0x%lx\n",
-                                       __func__, __pa(priv->pgtable));
-       }
+       else
+               dev_dbg(dev, "%s: Attached IOMMU with pgtable 0x%lx%s\n",
+                                       __func__, __pa(priv->pgtable),
+                                       (ret == 0) ? "" : ", again");
 
        return ret;
 }
@@ -791,39 +891,27 @@ static int exynos_iommu_attach_device(struct iommu_domain 
*domain,
 static void exynos_iommu_detach_device(struct iommu_domain *domain,
                                    struct device *dev)
 {
-       struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+       struct exynos_iommu_client *client = NULL;
        struct exynos_iommu_domain *priv = domain->priv;
-       struct list_head *pos;
        unsigned long flags;
-       bool found = false;
 
        spin_lock_irqsave(&priv->lock, flags);
 
-       list_for_each(pos, &priv->clients) {
-               if (list_entry(pos, struct sysmmu_drvdata, node) == data) {
-                       found = true;
+       list_for_each_entry(client, &priv->clients, node) {
+               if (client == dev->archdata.iommu) {
+                       if (exynos_sysmmu_disable(dev))
+                               list_del_init(&client->node);
                        break;
                }
        }
 
-       if (!found)
-               goto finish;
+       spin_unlock_irqrestore(&priv->lock, flags);
 
-       if (__exynos_sysmmu_disable(data)) {
+       if (client == dev->archdata.iommu)
                dev_dbg(dev, "%s: Detached IOMMU with pgtable %#lx\n",
                                        __func__, __pa(priv->pgtable));
-               list_del_init(&data->node);
-
-       } else {
-               dev_dbg(dev, "%s: Detaching IOMMU with pgtable %#lx delayed",
-                                       __func__, __pa(priv->pgtable));
-       }
-
-finish:
-       spin_unlock_irqrestore(&priv->lock, flags);
-
-       if (found)
-               pm_runtime_put(data->sysmmu);
+       else
+               dev_dbg(dev, "%s: No IOMMU is attached\n", __func__);
 }
 
 static unsigned long *alloc_lv2entry(unsigned long *sent, unsigned long iova,
@@ -940,7 +1028,7 @@ static size_t exynos_iommu_unmap(struct iommu_domain 
*domain,
                                               unsigned long iova, size_t size)
 {
        struct exynos_iommu_domain *priv = domain->priv;
-       struct sysmmu_drvdata *data;
+       struct exynos_iommu_client *client;
        unsigned long flags;
        unsigned long *ent;
        size_t err_page;
@@ -997,8 +1085,8 @@ done:
        spin_unlock_irqrestore(&priv->pgtablelock, flags);
 
        spin_lock_irqsave(&priv->lock, flags);
-       list_for_each_entry(data, &priv->clients, node)
-               sysmmu_tlb_invalidate_entry(data->dev, iova);
+       list_for_each_entry(client, &priv->clients, node)
+               sysmmu_tlb_invalidate_entry(client->dev, iova);
        spin_unlock_irqrestore(&priv->lock, flags);
 
        return size;
@@ -1082,3 +1170,275 @@ static int __init exynos_iommu_init(void)
        return ret;
 }
 subsys_initcall(exynos_iommu_init);
+
+#ifdef CONFIG_PM_SLEEP
+static int sysmmu_pm_genpd_suspend(struct device *dev)
+{
+       struct exynos_iommu_client *client = dev->archdata.iommu;
+       int ret = 0;
+       int i;
+
+       for (i = 0; i < client->num_sysmmu; i++) {
+               ret = pm_generic_suspend(client->sysmmu[i]);
+               if (ret)
+                       break;
+       }
+
+       if (!ret)
+               ret = pm_generic_suspend(dev);
+
+       if (ret) {
+               int j;
+
+               for (j = 0; j < i; j++)
+                       pm_generic_resume(client->sysmmu[j]);
+       }
+
+       return ret;
+}
+
+static int sysmmu_pm_genpd_resume(struct device *dev)
+{
+       struct exynos_iommu_client *client = dev->archdata.iommu;
+       int ret = 0;
+       int i;
+
+       for (i = 0; i < client->num_sysmmu; i++) {
+               ret = pm_generic_resume(client->sysmmu[i]);
+               if (ret)
+                       break;
+       }
+
+       if (!ret)
+               ret = pm_generic_resume(dev);
+
+       if (ret) {
+               int j;
+
+               for (j = 0; j < i; j++)
+                       pm_generic_suspend(client->sysmmu[j]);
+       }
+
+       return ret;
+}
+#endif
+
+#ifdef CONFIG_PM_RUNTIME
+static void sysmmu_restore_state(struct device *sysmmu)
+{
+       struct sysmmu_drvdata *data = dev_get_drvdata(sysmmu);
+       unsigned long flags;
+
+       spin_lock_irqsave(&data->lock, flags);
+       data->runtime_active = true;
+       if (is_sysmmu_active(data))
+               __sysmmu_enable_nocount(data);
+       spin_unlock_irqrestore(&data->lock, flags);
+}
+
+static void sysmmu_save_state(struct device *sysmmu)
+{
+       struct sysmmu_drvdata *data = dev_get_drvdata(sysmmu);
+       unsigned long flags;
+
+       spin_lock_irqsave(&data->lock, flags);
+       if (is_sysmmu_active(data))
+               __sysmmu_disable_nocount(data);
+       data->runtime_active = false;
+       spin_unlock_irqrestore(&data->lock, flags);
+}
+
+static int sysmmu_pm_genpd_save_state(struct device *dev)
+{
+       struct exynos_iommu_client *client = dev->archdata.iommu;
+       int (*cb)(struct device *__dev);
+       int i;
+
+       if (dev->type && dev->type->pm)
+               cb = dev->type->pm->runtime_suspend;
+       else if (dev->class && dev->class->pm)
+               cb = dev->class->pm->runtime_suspend;
+       else if (dev->bus && dev->bus->pm)
+               cb = dev->bus->pm->runtime_suspend;
+       else
+               cb = NULL;
+
+       if (!cb && dev->driver && dev->driver->pm)
+               cb = dev->driver->pm->runtime_suspend;
+
+       if (cb) {
+               int ret;
+
+               ret = cb(dev);
+               if (ret)
+                       return ret;
+       }
+
+       for (i = 0; i < client->num_sysmmu; i++)
+               sysmmu_save_state(client->sysmmu[i]);
+
+       return 0;
+}
+
+static int sysmmu_pm_genpd_restore_state(struct device *dev)
+{
+       struct exynos_iommu_client *client = dev->archdata.iommu;
+       int (*cb)(struct device *__dev);
+       int i;
+
+       if (dev->type && dev->type->pm)
+               cb = dev->type->pm->runtime_resume;
+       else if (dev->class && dev->class->pm)
+               cb = dev->class->pm->runtime_resume;
+       else if (dev->bus && dev->bus->pm)
+               cb = dev->bus->pm->runtime_resume;
+       else
+               cb = NULL;
+
+       if (!cb && dev->driver && dev->driver->pm)
+               cb = dev->driver->pm->runtime_resume;
+
+       for (i = 0; i < client->num_sysmmu; i++)
+               sysmmu_restore_state(client->sysmmu[i]);
+
+       if (cb) {
+               int ret;
+               ret = cb(dev);
+               if (ret) {
+                       for (i = 0; i < client->num_sysmmu; i++)
+                               sysmmu_save_state(client->sysmmu[i]);
+                       return ret;
+               }
+       }
+
+       return 0;
+}
+#endif
+
+#ifdef CONFIG_PM_GENERIC_DOMAINS
+struct gpd_dev_ops sysmmu_devpm_ops = {
+#ifdef CONFIG_PM_RUNTIME
+       .save_state = &sysmmu_pm_genpd_save_state,
+       .restore_state = &sysmmu_pm_genpd_restore_state,
+#endif
+#ifdef CONFIG_PM_SLEEP
+       .suspend = &sysmmu_pm_genpd_suspend,
+       .resume = &sysmmu_pm_genpd_resume,
+#endif
+};
+#endif /* CONFIG_PM_GENERIC_DOMAINS */
+
+static int sysmmu_hook_driver_register(struct notifier_block *nb,
+                                       unsigned long val,
+                                       void *p)
+{
+       struct device *dev = p;
+
+       switch (val) {
+       case BUS_NOTIFY_BIND_DRIVER:
+       {
+               int i = 0;
+               int size = 0;
+               const __be32 *phandle;
+               struct exynos_iommu_client *client;
+
+               phandle = of_get_property(dev->of_node, "iommu", &size);
+               if (!phandle)
+                       break;
+
+               size = size / sizeof(*phandle); /* number of elements */
+
+               client = devm_kzalloc(dev, sizeof(*client) * size, GFP_KERNEL);
+               if (!client) {
+                       dev_err(dev, "No Memory for exynos_iommu_client\n");
+                       return -ENOMEM;
+               }
+
+               client->num_sysmmu = size;
+               client->dev = dev;
+               INIT_LIST_HEAD(&client->node);
+               spin_lock_init(&client->lock);
+
+               for (i = 0; i < size; i++) {
+                       struct device_node *np;
+                       struct platform_device *sysmmu;
+
+                       /* this always success: see above of_find_property() */
+                       np = of_parse_phandle(dev->of_node, "iommu", i);
+
+                       sysmmu = of_find_device_by_node(np);
+                       if (!sysmmu) {
+                               dev_err(dev,
+                                       "sysmmu node '%s' is not found\n",
+                                       np->name);
+                               break;
+                       }
+
+                       client->sysmmu[i] = &sysmmu->dev;
+               }
+
+               if (i < size) {
+                       while (--i >= 0)
+                               of_node_put(client->sysmmu[i]->of_node);
+                       devm_kfree(dev, client);
+                       return -ENODEV;
+               }
+
+               i = pm_genpd_add_callbacks(dev, &sysmmu_devpm_ops, NULL);
+               if (i && (i != -ENOSYS)) {
+                       dev_err(dev,
+                               "Failed to register 'dev_pm_ops' for iommu\n");
+                       devm_kfree(dev, client);
+                       return i;
+               }
+
+               dev->archdata.iommu = client;
+               break;
+       }
+       case BUS_NOTIFY_BOUND_DRIVER:
+       {
+               struct exynos_iommu_client *client = dev->archdata.iommu;
+               if (dev->archdata.iommu &&
+                               (!pm_runtime_enabled(dev) ||
+                                        IS_ERR(dev_to_genpd(dev)))) {
+                       int i;
+                       for (i = 0; i < client->num_sysmmu; i++) {
+                               struct sysmmu_drvdata *data;
+                               pm_runtime_disable(client->sysmmu[i]);
+                               data = dev_get_drvdata(client->sysmmu[i]);
+                               if (!data)
+                                       continue;
+                               data->runtime_active =
+                                       !pm_runtime_enabled(data->sysmmu);
+                               if (data->runtime_active &&
+                                               is_sysmmu_active(data))
+                                       __sysmmu_enable_nocount(data);
+                       }
+               }
+               break;
+       }
+       case BUS_NOTIFY_UNBOUND_DRIVER:
+       {
+               if (dev->archdata.iommu) {
+                       __pm_genpd_remove_callbacks(dev, false);
+
+                       devm_kfree(dev, dev->archdata.iommu);
+
+                       dev->archdata.iommu = NULL;
+               }
+               break;
+       }
+       } /* switch (val) */
+
+       return 0;
+}
+
+static struct notifier_block sysmmu_notifier = {
+       .notifier_call = &sysmmu_hook_driver_register,
+};
+
+static int __init exynos_iommu_prepare(void)
+{
+       return bus_register_notifier(&platform_bus_type, &sysmmu_notifier);
+}
+arch_initcall(exynos_iommu_prepare);
-- 
1.7.2.5


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