[PATCH v10 15/20] iommu/exynos: remove calls to Runtime PM APIfunctions

From: Cho KyongHo
Date: Sun Oct 06 2013 - 21:59:39 EST

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 | 337 +++++++++++++++++++++++++-----------------
1 files changed, 201 insertions(+), 136 deletions(-)

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 976b88a..d9c5416 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>
@@ -154,6 +156,12 @@ 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;
+ struct device *sysmmu;
+};
+
struct exynos_iommu_domain {
struct list_head clients; /* list of sysmmu_drvdata.node */
unsigned long *pgtable; /* lv1 page table, 16KB */
@@ -163,9 +171,8 @@ 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;
@@ -250,7 +257,6 @@ 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);
@@ -310,7 +316,7 @@ 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 */
@@ -327,125 +333,145 @@ 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;
-
clk_enable(data->clk_master);

__raw_writel(CTRL_DISABLE, data->sfrbase + REG_MMU_CTRL);
+ __raw_writel(0, data->sfrbase + REG_MMU_CFG);

+ clk_disable(data->clk);
clk_disable(data->clk_master);
+}

- clk_disable(data->clk);
+static bool __sysmmu_disable(struct sysmmu_drvdata *data)
+{
+ bool disabled;
+ unsigned long flags;

- disabled = true;
- data->pgtable = 0;
- data->domain = NULL;
-finish:
- write_unlock_irqrestore(&data->lock, 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,
- unsigned long pgtable, struct iommu_domain *domain)
+static void __sysmmu_init_config(struct sysmmu_drvdata *data)
{
- int ret = 0;
- unsigned long flags;
- unsigned int min;
+ unsigned long cfg = 0;
+ int maj, min = 0;

- write_lock_irqsave(&data->lock, flags);
+ maj = __sysmmu_version(data, &min);
+ if ((maj == 3) && (min > 1))
+ cfg |= CFG_FLPDCACHE;

- if (!set_sysmmu_active(data)) {
- if (WARN_ON(pgtable != data->pgtable)) {
- ret = -EBUSY;
- set_sysmmu_inactive(data);
- } else {
- ret = 1;
- }
-
- dev_dbg(data->sysmmu, "Already enabled\n");
- goto finish;
- }
-
-
- data->pgtable = pgtable;
+ __raw_writel(cfg, data->sfrbase + REG_MMU_CFG);
+}

+static void __sysmmu_enable_nocount(struct sysmmu_drvdata *data)
+{
clk_enable(data->clk);
clk_enable(data->clk_master);

- __sysmmu_set_ptbase(data->sfrbase, pgtable);
+ __raw_writel(CTRL_BLOCK, data->sfrbase + REG_MMU_CTRL);

- if ((__sysmmu_version(data, &min) == 3) && (min > 1)) {
- unsigned long cfg;
- cfg = __raw_readl(data->sfrbase + REG_MMU_CFG);
- __raw_writel(cfg | CFG_FLPDCACHE, data->sfrbase + REG_MMU_CFG);
- }
+ __sysmmu_init_config(data);
+
+ __sysmmu_set_ptbase(data->sfrbase, data->pgtable);

__raw_writel(CTRL_ENABLE, data->sfrbase + REG_MMU_CTRL);

clk_disable(data->clk_master);
+}

- data->domain = domain;
+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;
+
+ __sysmmu_enable_nocount(data);
+
+ dev_dbg(data->sysmmu, "Enabled\n");
+ } else {
+ ret = (pgtable == data->pgtable) ? 1 : -EBUSY;
+
+ dev_dbg(data->sysmmu, "already enabled\n");
+ }
+
+ if (WARN_ON(ret < 0))
+ set_sysmmu_inactive(data); /* decrement count */

- dev_dbg(data->sysmmu, "Enabled\n");
-finish:
write_unlock_irqrestore(&data->lock, flags);

return ret;
}

-int exynos_sysmmu_enable(struct device *dev, unsigned long pgtable)
+/* __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)
{
- struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
int ret;
+ struct exynos_iommu_client *client = dev->archdata.iommu;
+ struct sysmmu_drvdata *data;

- BUG_ON(!memblock_is_memory(pgtable));
+ if (WARN_ON(!client))
+ return -ENODEV;

- ret = pm_runtime_get_sync(data->sysmmu);
- if (ret < 0) {
- dev_dbg(data->sysmmu, "Failed to enable\n");
- return ret;
- }
+ data = dev_get_drvdata(client->sysmmu);

- 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 = __sysmmu_enable(data, pgtable, domain);
+ if (ret >= 0)
+ data->master = dev;

return ret;
}

+int exynos_sysmmu_enable(struct device *dev, unsigned long pgtable)
+{
+ BUG_ON(!memblock_is_memory(pgtable));
+
+ 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;
+ struct exynos_iommu_client *client = dev->archdata.iommu;
+ struct sysmmu_drvdata *data;
+
+ if (WARN_ON(!client))
+ return true;

- disabled = __exynos_sysmmu_disable(data);
- pm_runtime_put(data->sysmmu);
+ data = dev_get_drvdata(client->sysmmu);
+
+ disabled = __sysmmu_disable(data);
+ if (disabled)
+ data->master = NULL;

return disabled;
}
@@ -453,11 +479,13 @@ 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_client *client = 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(client->sysmmu);

+ read_lock_irqsave(&data->lock, flags);
if (is_sysmmu_active(data)) {
unsigned int num_inv = 1;
/*
@@ -477,19 +505,21 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova,
}
clk_disable(data->clk_master);
} 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_client *client = 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(client->sysmmu);

+ read_lock_irqsave(&data->lock, flags);
if (is_sysmmu_active(data)) {
clk_enable(data->clk_master);
if (sysmmu_block(data->sfrbase)) {
@@ -498,9 +528,8 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
}
clk_disable(data->clk_master);
} else {
- dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n");
+ dev_dbg(dev, "disabled. Skipping TLB invalidation\n");
}
-
read_unlock_irqrestore(&data->lock, flags);
}

@@ -563,7 +592,6 @@ static int __init exynos_sysmmu_probe(struct platform_device *pdev)

data->sysmmu = dev;
rwlock_init(&data->lock);
- INIT_LIST_HEAD(&data->node);

platform_set_drvdata(pdev, data);

@@ -637,7 +665,7 @@ 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;

@@ -645,11 +673,14 @@ 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++)
@@ -666,41 +697,26 @@ 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;
}
@@ -708,39 +724,27 @@ 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,
@@ -870,7 +874,7 @@ 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_pgsize;
@@ -931,8 +935,8 @@ 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(client, &priv->clients, node)
+ sysmmu_tlb_invalidate_entry(client->dev, iova, size);
spin_unlock_irqrestore(&priv->lock, flags);

return size;
@@ -1017,3 +1021,64 @@ 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_client *client;
+ struct device_node *np;
+ struct platform_device *sysmmu;
+
+ np = of_parse_phandle(dev->of_node, "iommu", 0);
+ if (!np)
+ break;
+
+ client = devm_kzalloc(dev, sizeof(*client), GFP_KERNEL);
+ if (!client) {
+ dev_err(dev, "No Memory for exynos_iommu_client\n");
+ return -ENOMEM;
+ }
+
+ client->dev = dev;
+ INIT_LIST_HEAD(&client->node);
+
+ sysmmu = of_find_device_by_node(np);
+ if (!sysmmu) {
+ dev_err(dev, "sysmmu node '%s' not found\n", np->name);
+ devm_kfree(dev, client);
+ return -ENODEV;
+ }
+
+ client->sysmmu = &sysmmu->dev;
+
+ dev->archdata.iommu = client;
+ break;
+ }
+ case BUS_NOTIFY_UNBOUND_DRIVER:
+ {
+ if (dev->archdata.iommu) {
+ 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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