Re: [PATCH v8 10/12] iommu/exynos: add bus notifier for registering System MMU

Rahul Sharma
2013-08-02T05:17:37Z

Hi Cho,

On Fri, Jul 26, 2013 at 5:00 PM, Cho KyongHo <pullip.cho@samsung.com> wrote:
> When a device driver is registered, all constructs to handle System MMU
> is prepared by bus notifier call.
>
> Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
> ---
> drivers/iommu/exynos-iommu.c | 708 ++++++++++++++++++++++++++++++++---------
> 1 files changed, 552 insertions(+), 156 deletions(-)
>
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index f9853fe..c62c244 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>
> @@ -80,7 +83,13 @@
> #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
> @@ -154,6 +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];

Shouldn't we keep limit on the max number of iommu's to a single client ? Even
this way, you will hit array overrun with multiple iommu's.

> +};
> +
> struct exynos_iommu_domain {
> struct list_head clients; /* list of sysmmu_drvdata.node */
> unsigned long *pgtable; /* lv1 page table, 16KB */
> @@ -165,12 +182,14 @@ 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;
> + struct clk *clk_master;
> int activations;
> rwlock_t lock;
> struct iommu_domain *domain;
> + bool runtime_active;
> unsigned long pgtable;
> void __iomem *sfrbases[0];
> };
> @@ -245,7 +264,6 @@ 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);
> @@ -273,6 +291,7 @@ void exynos_sysmmu_set_prefbuf(struct device *dev,
> if (!is_sysmmu_active(data))
> goto finish;
>
> + clk_enable(data->clk_master);
> for (i = 0; i < data->nsfrs; i++) {
> if ((readl(data->sfrbases[i] + REG_MMU_VERSION) >> 28) == 3) {
> if (!sysmmu_block(data->sfrbases[i]))
> @@ -298,6 +317,7 @@ void exynos_sysmmu_set_prefbuf(struct device *dev,
> sysmmu_unblock(data->sfrbases[i]);
> }
> }
> + clk_disable(data->clk_master);
> finish:
> read_unlock_irqrestore(&data->lock, flags);
> }
> @@ -331,12 +351,13 @@ 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 exynos_iommu_client *client = NULL;
> enum exynos_sysmmu_inttype itype;
> unsigned long addr = -1;
> -
> int i, ret = -ENOSYS;
>
> - read_lock(&data->lock);
> + if (data->master)
> + client = data->master->archdata.iommu;
>
> WARN_ON(!is_sysmmu_active(data));
>
> @@ -348,6 +369,10 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
> break;
> }
>
> + if (client)
> + spin_lock(&client->lock);
> + read_lock(&data->lock);
> +
> if (i == data->nsfrs) {
> itype = SYSMMU_FAULT_UNKNOWN;
> } else {
> @@ -361,7 +386,7 @@ 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 && (itype != SYSMMU_FAULT_UNKNOWN))
> @@ -378,177 +403,251 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
> sysmmu_unblock(data->sfrbases[i]);
>
> read_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)
> {
> - unsigned long flags;
> - bool disabled = false;
> int i;
>
> - write_lock_irqsave(&data->lock, flags);
> + clk_enable(data->clk_master);
> + 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);
> + }
>
> - if (!set_sysmmu_inactive(data))
> - goto finish;
> + clk_disable(data->clk);
> + clk_disable(data->clk_master);
> +}
>
> - for (i = 0; i < data->nsfrs; i++)
> - __raw_writel(CTRL_DISABLE, data->sfrbases[i] + REG_MMU_CTRL);
> +static bool __sysmmu_disable(struct sysmmu_drvdata *data)
> +{
> + bool disabled;
> + unsigned long flags;
>
> - if (data->clk)
> - clk_disable(data->clk);
> + write_lock_irqsave(&data->lock, flags);
>
> - disabled = true;
> - data->pgtable = 0;
> - data->domain = NULL;
> -finish:
> - write_unlock_irqrestore(&data->lock, flags);
> + disabled = set_sysmmu_inactive(data);
> +
> + if (disabled) {
> + data->pgtable = 0;
> + data->domain = NULL;
> +
> + if (data->runtime_active)
> + __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, int idx)
> +{
> + unsigned long cfg = CFG_LRU | CFG_QOS(15);
> + int maj, min = 0;
> +
> + maj = __sysmmu_version(data, idx, &min);
> + if (maj == 3) {
> + if (min > 1) {
> + cfg |= CFG_FLPDCACHE;
> + cfg |= (min == 2) ? CFG_SYSSEL : CFG_ACGEN;
> + }
> + }
> +
> + __raw_writel(cfg, data->sfrbases[idx] + REG_MMU_CFG);
> +}
> +
> +static void __sysmmu_enable_nocount(struct sysmmu_drvdata *data)
> +{
> + int i;
> +
> + clk_enable(data->clk_master);
> + clk_enable(data->clk);
> +
> + for (i = 0; i < data->nsfrs; i++) {
> + __raw_writel(CTRL_BLOCK, data->sfrbases[i] + REG_MMU_CTRL);
> +
> + __sysmmu_init_config(data, i);
> +
> + __sysmmu_set_ptbase(data->sfrbases[i], data->pgtable);
> +
> + __raw_writel(CTRL_ENABLE, data->sfrbases[i] + REG_MMU_CTRL);
> + }
> + clk_disable(data->clk_master);
> +}
> +
> +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;
>
> 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;
> - }
> + 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;
> + write_unlock_irqrestore(&data->lock, flags);
>
> - for (i = 0; i < data->nsfrs; i++) {
> - unsigned int min;
> + return ret;
> +}
>
> - __sysmmu_set_ptbase(data->sfrbases[i], 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)
> +{
> + int ret = 0;
> + unsigned long flags;
> + struct exynos_iommu_client *client = dev->archdata.iommu;
> + int i;
>
> - if ((__sysmmu_version(data, i, &min) == 3) && (min > 1)) {
> - unsigned long cfg;
> - cfg = __raw_readl(data->sfrbases[i] + REG_MMU_CFG);
> - __raw_writel(cfg | CFG_FLPDCACHE,
> - data->sfrbases[i] + REG_MMU_CFG);
> - }
> + if (WARN_ON(!client))
> + return -ENODEV;
>
> - __raw_writel(CTRL_ENABLE, data->sfrbases[i] + REG_MMU_CTRL);
> - }
> + spin_lock_irqsave(&client->lock, flags);
>
> - data->domain = domain;
> + 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;
> + }
> + }
>
> - dev_dbg(data->sysmmu, "Enabled\n");
> -finish:
> - write_unlock_irqrestore(&data->lock, flags);
> + 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;
>
> - disabled = __exynos_sysmmu_disable(data);
> - pm_runtime_put(data->sysmmu);
> + 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;
> + }
> +
> + 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;
>
> - read_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]);
> +
> + read_lock_irqsave(&data->lock, flags);
> + if (is_sysmmu_active(data) && data->runtime_active) {
> + int i;
> + clk_enable(data->clk_master);
> + for (i = 0; i < data->nsfrs; i++)
> __sysmmu_tlb_invalidate_entry(
> data->sfrbases[i], iova);
> - sysmmu_unblock(data->sfrbases[i]);
> - }
> + clk_disable(data->clk_master);
> + } else {
> + dev_dbg(dev,
> + "disabled. Skipping TLB invalidation @ %#lx\n",
> + iova);
> }
> - } else {
> - dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n");
> + read_unlock_irqrestore(&data->lock, flags);
> }
> -
> - read_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);
> -
> - read_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]);
> +
> + read_lock_irqsave(&data->lock, flags);
> + if (is_sysmmu_active(data) &&
> + data->runtime_active) {
> + int i;
> + for (i = 0; i < data->nsfrs; i++) {
> + clk_enable(data->clk_master);
> + if (sysmmu_block(data->sfrbases[i])) {
> + __sysmmu_tlb_invalidate(
> + data->sfrbases[i]);
> + sysmmu_unblock(data->sfrbases[i]);
> + }
> + clk_disable(data->clk_master);
> }
> + } else {
> + dev_dbg(dev, "disabled. Skipping TLB invalidation\n");
> }
> - } else {
> - dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n");
> + read_unlock_irqrestore(&data->lock, flags);
> }
> -
> - read_unlock_irqrestore(&data->lock, flags);
> }
>
> static int __init exynos_sysmmu_probe(struct platform_device *pdev)
> @@ -610,12 +709,32 @@ static int __init exynos_sysmmu_probe(struct platform_device *pdev)
> pm_runtime_enable(dev);
>
> data->sysmmu = dev;
> +
> data->clk = devm_clk_get(dev, "sysmmu");
> if (IS_ERR(data->clk)) {
> dev_info(dev, "No gate clock found!\n");
> data->clk = NULL;
> }
>
> + ret = clk_prepare(data->clk);
> + if (ret) {
> + dev_err(dev, "Failed to prepare clk\n");
> + return ret;
> + }
> +
> + data->clk_master = devm_clk_get(dev, "master");
> + if (IS_ERR(data->clk_master))
> + data->clk_master = NULL;
> +
> + ret = clk_prepare(data->clk_master);
> + if (ret) {
> + clk_unprepare(data->clk);
> + dev_err(dev, "Failed to prepare master's clk\n");
> + return ret;
> + }
> +
> + data->runtime_active = !pm_runtime_enabled(dev);
> +
> rwlock_init(&data->lock);
> INIT_LIST_HEAD(&data->node);
>
> @@ -625,6 +744,34 @@ 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;
> + read_lock_irqsave(&data->lock, flags);
> + if (is_sysmmu_active(data) &&
> + (!pm_runtime_enabled(dev) || data->runtime_active))
> + __sysmmu_disable_nocount(data);
> + read_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;
> + read_lock_irqsave(&data->lock, flags);
> + if (is_sysmmu_active(data) &&
> + (!pm_runtime_enabled(dev) || data->runtime_active))
> + __sysmmu_enable_nocount(data);
> + read_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", },
> @@ -637,6 +784,7 @@ 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),
> }
> };
> @@ -689,7 +837,7 @@ 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;
>
> @@ -697,11 +845,14 @@ 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++)
> @@ -718,41 +869,26 @@ 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;
> }
> @@ -760,39 +896,27 @@ 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,
> @@ -914,7 +1038,7 @@ 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;
> @@ -975,8 +1099,8 @@ 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;
> @@ -1055,3 +1179,275 @@ 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;

You can drop the initialization here. They are getting initialised
before actual use.

> + 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);

You do not need to allocate memory of size "sizeof(*client) * size" ? It should
always be sizeof(*client).

> + 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;

Your array has space for single 'device *'. You should allocate memory to
client->sysmmu before accessing indexes above 0.

As if now, It is not corrupting other's memory since you have allocated a
much bigger chunk for your client pointer which is wrong IMO.

regards,
Rahul Sharma

> + }
> +
> + 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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