Runtime power management by exynos-iommu driver independently from
master H/W's runtime pm is not useful for power saving since attaching
master H/W in probing time turns on its local power endlessly.
Thus this removes runtime pm API calls.
Runtime PM support is added in the following commits to exynos-iommu
driver.
Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
---
drivers/iommu/exynos-iommu.c | 369 +++++++++++++++++++++++++++---------------
1 file changed, 238 insertions(+), 131 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 3458349..6834556 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -27,6 +27,8 @@
#include <linux/memblock.h>
#include <linux/export.h>
#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/notifier.h>
#include <asm/cacheflush.h>
#include <asm/pgtable.h>
@@ -111,6 +113,8 @@
#define __master_clk_enable(data) __clk_gate_ctrl(data, clk_master, en)
#define __master_clk_disable(data) __clk_gate_ctrl(data, clk_master, dis)
+#define has_sysmmu(dev) (dev->archdata.iommu != NULL)
+
static struct kmem_cache *lv2table_kmem_cache;
static unsigned long *section_entry(unsigned long *pgtable, unsigned long iova)
@@ -159,6 +163,16 @@ static char *sysmmu_fault_name[SYSMMU_FAULTS_NUM] = {
"UNKNOWN FAULT"
};
+/* attached to dev.archdata.iommu of the master device */
+struct exynos_iommu_owner {
+ struct list_head client; /* entry of exynos_iommu_domain.clients */
+ struct device *dev;
+ struct device *sysmmu;
+ struct iommu_domain *domain;
+ void *vmm_data; /* IO virtual memory manager's data */
+ spinlock_t lock; /* Lock to preserve consistency of System MMU */
+};
+
struct exynos_iommu_domain {
struct list_head clients; /* list of sysmmu_drvdata.node */
unsigned long *pgtable; /* lv1 page table, 16KB */
@@ -168,9 +182,8 @@ 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 */
void __iomem *sfrbase;
struct clk *clk;
struct clk *clk_master;
@@ -239,7 +252,6 @@ 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);
@@ -299,7 +311,7 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
itype, base, addr);
if (data->domain)
ret = report_iommu_fault(data->domain,
- data->dev, addr, itype);
+ data->master, addr, itype);
}
/* fault is not recovered by fault handler */
@@ -316,116 +328,148 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
return IRQ_HANDLED;
}
-static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data)
+static void __sysmmu_disable_nocount(struct sysmmu_drvdata *data)
{
- unsigned long flags;
- bool disabled = false;
-
- write_lock_irqsave(&data->lock, flags);
-
- if (!set_sysmmu_inactive(data))
- goto finish;
-
- __master_clk_enable(data);
+ clk_enable(data->clk_master);
__raw_writel(CTRL_DISABLE, data->sfrbase + REG_MMU_CTRL);
+ __raw_writel(0, data->sfrbase + REG_MMU_CFG);
__sysmmu_clk_disable(data);
__master_clk_disable(data);
+}
- disabled = true;
- data->pgtable = 0;
- data->domain = NULL;
-finish:
- write_unlock_irqrestore(&data->lock, flags);
+static bool __sysmmu_disable(struct sysmmu_drvdata *data)
+{
+ bool disabled;
+ unsigned long flags;
+
+ write_lock_irqsave(&data->lock, flags);
+
+ disabled = set_sysmmu_inactive(data);
+
+ if (disabled) {
+ data->pgtable = 0;
+ data->domain = NULL;
+
+ __sysmmu_disable_nocount(data);
- 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);
+ }
+
+ write_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)
+{
+ unsigned long cfg = 0;
+
+ __raw_writel(cfg, data->sfrbase + REG_MMU_CFG);
+}
+
+static void __sysmmu_enable_nocount(struct sysmmu_drvdata *data)
+{
+ __master_clk_enable(data);
+ __sysmmu_clk_enable(data);
+
+ __raw_writel(CTRL_BLOCK, data->sfrbase + REG_MMU_CTRL);
+
+ __sysmmu_init_config(data);
+
+ __sysmmu_set_ptbase(data->sfrbase, data->pgtable);
+
+ __raw_writel(CTRL_ENABLE, data->sfrbase + REG_MMU_CTRL);
+
+ __master_clk_disable(data);
+}
+
+static int __sysmmu_enable(struct sysmmu_drvdata *data,
unsigned long pgtable, struct iommu_domain *domain)
{
int ret = 0;
unsigned long flags;
write_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;
- }
+ __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");
}
- data->pgtable = pgtable;
+ if (WARN_ON(ret < 0))
+ set_sysmmu_inactive(data); /* decrement count */
- __master_clk_enable(data);
- __sysmmu_clk_enable(data);
+ write_unlock_irqrestore(&data->lock, flags);
- __sysmmu_set_ptbase(data->sfrbase, pgtable);
+ return ret;
+}
- __raw_writel(CTRL_ENABLE, data->sfrbase + REG_MMU_CTRL);
+/* __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_owner *owner = dev->archdata.iommu;
+ struct sysmmu_drvdata *data;
- __master_clk_disable(data);
+ BUG_ON(!has_sysmmu(dev));
- data->domain = domain;
+ spin_lock_irqsave(&owner->lock, flags);
- dev_dbg(data->sysmmu, "Enabled\n");
-finish:
- write_unlock_irqrestore(&data->lock, flags);
+ data = dev_get_drvdata(owner->sysmmu);
+
+ ret = __sysmmu_enable(data, pgtable, domain);
+ if (ret >= 0)
+ data->master = dev;
+
+ spin_unlock_irqrestore(&owner->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;
- }
-
- return ret;
+ return __exynos_sysmmu_enable(dev, pgtable, NULL);
}
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_owner *owner = dev->archdata.iommu;
+ struct sysmmu_drvdata *data;
+
+ BUG_ON(!has_sysmmu(dev));
- disabled = __exynos_sysmmu_disable(data);
- pm_runtime_put(data->sysmmu);
+ spin_lock_irqsave(&owner->lock, flags);
+
+ data = dev_get_drvdata(owner->sysmmu);
+
+ disabled = __sysmmu_disable(data);
+ if (disabled)
+ data->master = NULL;
+
+ spin_unlock_irqrestore(&owner->lock, flags);
return disabled;
}
@@ -433,11 +477,13 @@ static bool exynos_sysmmu_disable(struct device *dev)
static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova,
size_t size)
{
+ struct exynos_iommu_owner *owner = dev->archdata.iommu;
unsigned long flags;
- struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+ struct sysmmu_drvdata *data;
- read_lock_irqsave(&data->lock, flags);
+ data = dev_get_drvdata(owner->sysmmu);
+ read_lock_irqsave(&data->lock, flags);
if (is_sysmmu_active(data)) {
unsigned int maj;
unsigned int num_inv = 1;
@@ -465,19 +511,21 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova,
}
__master_clk_disable(data);
} else {
- dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n");
+ dev_dbg(dev, "disabled. Skipping TLB invalidation @ %#lx\n",
+ iova);
}
-
read_unlock_irqrestore(&data->lock, flags);
}
void exynos_sysmmu_tlb_invalidate(struct device *dev)
{
+ struct exynos_iommu_owner *owner = dev->archdata.iommu;
unsigned long flags;
- struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+ struct sysmmu_drvdata *data;
- read_lock_irqsave(&data->lock, flags);
+ data = dev_get_drvdata(owner->sysmmu);
+ read_lock_irqsave(&data->lock, flags);
if (is_sysmmu_active(data)) {
__master_clk_enable(data);
if (sysmmu_block(data->sfrbase)) {
@@ -486,9 +534,8 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
}
__master_clk_disable(data);
} else {
- dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n");
+ dev_dbg(dev, "disabled. Skipping TLB invalidation\n");
}
-
read_unlock_irqrestore(&data->lock, flags);
}
@@ -498,6 +545,7 @@ static int __init exynos_sysmmu_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct sysmmu_drvdata *data;
struct resource *res;
+ struct device_node *node;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
@@ -549,9 +597,32 @@ static int __init exynos_sysmmu_probe(struct platform_device *pdev)
return ret;
}
+ /* Relation between master and System MMU is 1:1. */
+ node = of_parse_phandle(dev->of_node, "mmu-masters", 0);
+ if (node) {
+ struct platform_device *master = of_find_device_by_node(node);
+
+ if (!master) {
+ dev_err(dev, "%s: mmu-master '%s' not found\n",
+ __func__, node->name);
+ return -EINVAL;
+ }
+
+ if (master->dev.archdata.iommu != NULL) {
+ dev_err(dev, "%s: '%s' is master of other MMU\n",
+ __func__, node->name);
+ return -EINVAL;
+ }
+
+ /*
+ * archdata.iommu will be initialized with exynos_iommu_client
+ * in sysmmu_hook_driver_register().
+ */
+ master->dev.archdata.iommu = dev;
+ }
+
data->sysmmu = dev;
rwlock_init(&data->lock);
- INIT_LIST_HEAD(&data->node);
platform_set_drvdata(pdev, data);
@@ -629,7 +700,7 @@ 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_owner *owner;
unsigned long flags;
int i;
@@ -637,11 +708,14 @@ 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(owner, &priv->clients, client) {
+ while (!exynos_sysmmu_disable(owner->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++)
@@ -658,41 +732,28 @@ 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_owner *owner = 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);
-
+ ret = __exynos_sysmmu_enable(dev, __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);
+ list_add_tail(&owner->client, &priv->clients);
+ owner->domain = domain;
}
spin_unlock_irqrestore(&priv->lock, flags);
- if (ret < 0) {
- dev_err(dev, "%s: Failed to attach IOMMU with pgtable %#lx\n",
+ if (ret < 0)
+ dev_err(dev, "%s: Failed to attach IOMMU with pgtable %#x\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%x%s\n",
+ __func__, __pa(priv->pgtable),
+ (ret == 0) ? "" : ", again");
return ret;
}
@@ -700,39 +761,29 @@ 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_owner *owner;
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(owner, &priv->clients, client) {
+ if (owner == dev->archdata.iommu) {
+ if (exynos_sysmmu_disable(dev)) {
+ list_del_init(&owner->client);
+ owner->domain = NULL;
+ }
break;
}
}
- if (!found)
- goto finish;
-
- if (__exynos_sysmmu_disable(data)) {
- 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);
+ if (owner == dev->archdata.iommu)
+ dev_dbg(dev, "%s: Detached IOMMU with pgtable %#x\n",
+ __func__, __pa(priv->pgtable));
+ else
+ dev_dbg(dev, "%s: No IOMMU is attached\n", __func__);
}
static unsigned long *alloc_lv2entry(unsigned long *sent, unsigned long iova,
@@ -862,7 +913,7 @@ 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_owner *owner;
unsigned long flags;
unsigned long *ent;
size_t err_pgsize;
@@ -923,8 +974,8 @@ 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, size);
+ list_for_each_entry(owner, &priv->clients, client)
+ sysmmu_tlb_invalidate_entry(owner->dev, iova, size);
spin_unlock_irqrestore(&priv->lock, flags);
return size;
@@ -1009,3 +1060,59 @@ err_reg_driver:
return ret;
}
subsys_initcall(exynos_iommu_init);
+
+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:
+ {
+ struct exynos_iommu_owner *owner;
+
+ /* No System MMU assigned. See exynos_sysmmu_probe(). */
+ if (dev->archdata.iommu == NULL)
+ break;
+
+ owner = devm_kzalloc(dev, sizeof(*owner), GFP_KERNEL);
+ if (!owner) {
+ dev_err(dev, "No Memory for exynos_iommu_owner\n");
+ return -ENOMEM;
+ }
+
+ owner->dev = dev;
+ INIT_LIST_HEAD(&owner->client);
+ owner->sysmmu = dev->archdata.iommu;
+
+ dev->archdata.iommu = owner;
+ break;
+ }
+ case BUS_NOTIFY_UNBOUND_DRIVER:
+ {
+ struct exynos_iommu_owner *owner = dev->archdata.iommu;
+ if (owner) {
+ struct device *sysmmu = owner->sysmmu;
+ /* if still attached to an iommu_domain. */
+ if (WARN_ON(!list_empty(&owner->client)))
+ iommu_detach_device(owner->domain, owner->dev);
+ devm_kfree(dev, owner);
+ dev->archdata.iommu = sysmmu;
+ }
+ 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);
--
1.7.9.5
--
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