Re: [PATCH v9 07/16] iommu/exynos: support for device tree
From: Tomasz Figa
Date: Thu Aug 08 2013 - 18:41:40 EST
Hi KyongHo,
On Thursday 08 of August 2013 18:38:49 Cho KyongHo wrote:
> This commit adds device tree support for System MMU.
> This also include the following changes and enhancements:
>
> * use managed device helper functions.
> Simplyfies System MMU device driver.
>
> * use only a single clock descriptor.
> System MMU device descriptor is seperate if it is imposible to make
> a single clock descriptor to make a device descriptor for a group of
> System MMUs.
>
> * removed dbgname member from sysmmu_drvdata structure.
> debugging kernel message for a System MMU is distinguisheable with the
> name of device descroptors.
Please put all these three changes in separate patches. This patch is hard
to review with all the changes mixed together...
In addition, I believe this is the patch that should be adding device tree
binding documentation, not the 6/16 one, as this is where actually support
for this binding gets added to the kernel.
> Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
> ---
> drivers/iommu/Kconfig | 5 +-
> drivers/iommu/exynos-iommu.c | 186
> ++++++++++++++++------------------------- 2 files changed, 75
> insertions(+), 116 deletions(-)
>
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index 820d85c..9ad45f1 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -168,16 +168,15 @@ config TEGRA_IOMMU_SMMU
>
> config EXYNOS_IOMMU
> bool "Exynos IOMMU Support"
> - depends on ARCH_EXYNOS && EXYNOS_DEV_SYSMMU
> + depends on ARCH_EXYNOS
> select IOMMU_API
> + default n
> help
> Support for the IOMMU(System MMU) of Samsung Exynos application
> processor family. This enables H/W multimedia accellerators to
see
> non-linear physical memory chunks as a linear memory in their
> address spaces
>
> - If unsure, say N here.
> -
> config EXYNOS_IOMMU_DEBUG
> bool "Debugging log for Exynos IOMMU"
> depends on EXYNOS_IOMMU
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index a318049..0ee73e8 100644
> --- a/drivers/iommu/exynos-iommu.c
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -26,6 +26,7 @@
> #include <linux/list.h>
> #include <linux/memblock.h>
> #include <linux/export.h>
> +#include <linux/of.h>
>
> #include <asm/cacheflush.h>
> #include <asm/pgtable.h>
> @@ -170,15 +171,14 @@ 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 */
> - char *dbgname;
> int nsfrs;
> - void __iomem **sfrbases;
> - struct clk *clk[2];
> + struct clk *clk;
> int activations;
> rwlock_t lock;
> struct iommu_domain *domain;
> sysmmu_fault_handler_t fault_handler;
> unsigned long pgtable;
> + void __iomem *sfrbases[0];
> };
>
> static bool set_sysmmu_active(struct sysmmu_drvdata *data)
> @@ -385,8 +385,8 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void
> *dev_id) if (!ret && (itype != SYSMMU_FAULT_UNKNOWN))
> __raw_writel(1 << itype, data->sfrbases[i] +
REG_INT_CLEAR);
> else
> - dev_dbg(data->sysmmu, "(%s) %s is not handled.\n",
> - data->dbgname, sysmmu_fault_name[itype]);
> + dev_dbg(data->sysmmu, "%s is not handled.\n",
> + sysmmu_fault_name[itype]);
>
> if (itype != SYSMMU_FAULT_UNKNOWN)
> sysmmu_unblock(data->sfrbases[i]);
> @@ -410,10 +410,8 @@ static bool __exynos_sysmmu_disable(struct
> sysmmu_drvdata *data) for (i = 0; i < data->nsfrs; i++)
> __raw_writel(CTRL_DISABLE, data->sfrbases[i] +
REG_MMU_CTRL);
>
> - if (data->clk[1])
> - clk_disable(data->clk[1]);
> - if (data->clk[0])
> - clk_disable(data->clk[0]);
> + if (data->clk)
> + clk_disable(data->clk);
>
> disabled = true;
> data->pgtable = 0;
> @@ -422,10 +420,10 @@ finish:
> write_unlock_irqrestore(&data->lock, flags);
>
> if (disabled)
> - dev_dbg(data->sysmmu, "(%s) Disabled\n", data->dbgname);
> + dev_dbg(data->sysmmu, "Disabled\n");
> else
> - dev_dbg(data->sysmmu, "(%s) %d times left to be
disabled\n",
> - data->dbgname, data->activations);
> + dev_dbg(data->sysmmu, "%d times left to be disabled\n",
> + data->activations);
>
> return disabled;
> }
> @@ -452,14 +450,12 @@ static int __exynos_sysmmu_enable(struct
> sysmmu_drvdata *data, ret = 1;
> }
>
> - dev_dbg(data->sysmmu, "(%s) Already enabled\n", data-
>dbgname);
> + dev_dbg(data->sysmmu, "Already enabled\n");
> goto finish;
> }
>
> - if (data->clk[0])
> - clk_enable(data->clk[0]);
> - if (data->clk[1])
> - clk_enable(data->clk[1]);
> + if (data->clk)
> + clk_enable(data->clk);
>
> data->pgtable = pgtable;
>
> @@ -479,7 +475,7 @@ static int __exynos_sysmmu_enable(struct
> sysmmu_drvdata *data,
>
> data->domain = domain;
>
> - dev_dbg(data->sysmmu, "(%s) Enabled\n", data->dbgname);
> + dev_dbg(data->sysmmu, "Enabled\n");
> finish:
> write_unlock_irqrestore(&data->lock, flags);
>
> @@ -495,7 +491,7 @@ int exynos_sysmmu_enable(struct device *dev,
> unsigned long pgtable)
>
> ret = pm_runtime_get_sync(data->sysmmu);
> if (ret < 0) {
> - dev_dbg(data->sysmmu, "(%s) Failed to enable\n", data-
>dbgname);
> + dev_dbg(data->sysmmu, "Failed to enable\n");
> return ret;
> }
>
> @@ -503,8 +499,8 @@ int exynos_sysmmu_enable(struct device *dev,
> unsigned long pgtable) if (WARN_ON(ret < 0)) {
> pm_runtime_put(data->sysmmu);
> dev_err(data->sysmmu,
> - "(%s) Already enabled with page table %#lx\n",
> - data->dbgname, data->pgtable);
> + "Already enabled with page table %#lx\n",
> + data->pgtable);
> } else {
> data->dev = dev;
> }
> @@ -540,9 +536,7 @@ static void sysmmu_tlb_invalidate_entry(struct
> device *dev, unsigned long iova) }
> }
> } else {
> - dev_dbg(data->sysmmu,
> - "(%s) Disabled. Skipping invalidating TLB.\n",
> - data->dbgname);
> + dev_dbg(data->sysmmu, "Disabled. Skipping invalidating
TLB.\n");
> }
>
> read_unlock_irqrestore(&data->lock, flags);
> @@ -564,141 +558,107 @@ void exynos_sysmmu_tlb_invalidate(struct device
> *dev) }
> }
> } else {
> - dev_dbg(data->sysmmu,
> - "(%s) Disabled. Skipping invalidating TLB.\n",
> - data->dbgname);
> + dev_dbg(data->sysmmu, "Disabled. Skipping invalidating
TLB.\n");
> }
>
> read_unlock_irqrestore(&data->lock, flags);
> }
>
> -static int exynos_sysmmu_probe(struct platform_device *pdev)
> +static int __init exynos_sysmmu_probe(struct platform_device *pdev)
> {
> int i, ret;
> - struct device *dev;
> + struct device *dev = &pdev->dev;
> struct sysmmu_drvdata *data;
>
> - dev = &pdev->dev;
> -
> - data = kzalloc(sizeof(*data), GFP_KERNEL);
> - if (!data) {
> - dev_dbg(dev, "Not enough memory\n");
> - ret = -ENOMEM;
> - goto err_alloc;
> + if (pdev->num_resources == 0) {
> + dev_err(dev, "No System MMU resource defined\n");
> + return -ENODEV;
> }
>
> - ret = dev_set_drvdata(dev, data);
> - if (ret) {
> - dev_dbg(dev, "Unabled to initialize driver data\n");
> - goto err_init;
> + data = devm_kzalloc(dev,
> + sizeof(*data) +
> + sizeof(*data->sfrbases) * (pdev->num_resources /
2),
> + GFP_KERNEL);
> + if (!data) {
> + dev_err(dev, "Not enough memory for initialization\n");
nit: This message is not necessary, as kmalloc() already prints a message
if allocation error occurs.
> + return -ENOMEM;
> }
>
> data->nsfrs = pdev->num_resources / 2;
As Marek and Bart already mentioned before, please (oh please, really
please) finally remove this brokenness from this driver.
A device driver should not do this kind of abstraction, emulating one
instance of particular IP from multiple instances. This is a task for the
IOMMU core and this is already supported by IOMMU domains, which is the
right way to achieve a single virtual address space for multiple IOMMUs.
> - data->sfrbases = kmalloc(sizeof(*data->sfrbases) * data->nsfrs,
> -
GFP_KERNEL);
> - if (data->sfrbases == NULL) {
> - dev_dbg(dev, "Not enough memory\n");
> - ret = -ENOMEM;
> - goto err_init;
> - }
>
> for (i = 0; i < data->nsfrs; i++) {
> struct resource *res;
> +
> res = platform_get_resource(pdev, IORESOURCE_MEM, i);
> if (!res) {
> - dev_dbg(dev, "Unable to find IOMEM region\n");
> - ret = -ENOENT;
> - goto err_res;
> + dev_err(dev, "Unable to find IOMEM region\n");
> + return -ENOENT;
> }
>
> - data->sfrbases[i] = ioremap(res->start,
resource_size(res));
> + data->sfrbases[i] = devm_request_and_ioremap(dev, res);
devm_request_and_ioremap() is deprecated. Please use
devm_ioremap_resource().
> if (!data->sfrbases[i]) {
In case of devm_ioremap_resource() remember to adjust this check to check
for IS_ERR, not for NULL.
> - dev_dbg(dev, "Unable to map IOMEM @ PA:%#x\n",
> - res->start);
> - ret = -ENOENT;
> - goto err_res;
> + dev_err(dev, "Unable to map IOMEM @ %#x\n", res-
>start);
This message will not be needed with devm_ioremap_resource() as it already
prints a message if an error occurs.
> + return -EBUSY;
> }
> }
>
> for (i = 0; i < data->nsfrs; i++) {
> - ret = platform_get_irq(pdev, i);
> - if (ret <= 0) {
> - dev_dbg(dev, "Unable to find IRQ resource\n");
> - goto err_irq;
> + int irq;
> +
> + irq = platform_get_irq(pdev, i);
> + if (irq <= 0) {
> + dev_err(dev, "Unable to find IRQ resource\n");
> + return -ENOENT;
> }
>
> - ret = request_irq(ret, exynos_sysmmu_irq, 0,
> - dev_name(dev), data);
> + ret = devm_request_irq(dev, irq, exynos_sysmmu_irq,
> + 0, dev_name(dev), data);
> if (ret) {
> - dev_dbg(dev, "Unabled to register interrupt
handler\n");
> - goto err_irq;
> + dev_err(dev, "Unable to register handler to irq
%d\n",
> + irq);
> + return ret;
> }
> }
>
> - if (dev_get_platdata(dev)) {
> - char *deli, *beg;
> - struct sysmmu_platform_data *platdata =
dev_get_platdata(dev);
> -
> - beg = platdata->clockname;
> -
> - for (deli = beg; (*deli != '\0') && (*deli != ',');
deli++)
> - /* NOTHING */;
> + pm_runtime_enable(dev);
>
> - if (*deli == '\0')
> - deli = NULL;
> - else
> - *deli = '\0';
> -
> - data->clk[0] = clk_get(dev, beg);
> - if (IS_ERR(data->clk[0])) {
> - data->clk[0] = NULL;
> - dev_dbg(dev, "No clock descriptor registered\n");
> - }
> + __set_fault_handler(data, &default_fault_handler);
>
> - if (data->clk[0] && deli) {
> - *deli = ',';
> - data->clk[1] = clk_get(dev, deli + 1);
> - if (IS_ERR(data->clk[1]))
> - data->clk[1] = NULL;
> - }
> + 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;
Just a note: In common clock framework NULL is a valid value for a struct
clk *, which should not be interpreted as a pointer, but as an opaque
cookie. This is material for separate patch, but this should be fixed all
around this driver so data->clk is for IS_ERR instead.
Best regards,
Tomasz
> + }
>
> - data->dbgname = platdata->dbgname;
> + ret = clk_prepare(data->clk);
> + if (ret) {
> + dev_err(dev, "Failed to prepare clk\n");
> + return ret;
> }
>
> - data->sysmmu = dev;
> rwlock_init(&data->lock);
> INIT_LIST_HEAD(&data->node);
>
> - __set_fault_handler(data, &default_fault_handler);
> -
> - if (dev->parent)
> - pm_runtime_enable(dev);
> + platform_set_drvdata(pdev, data);
> + dev_dbg(dev, "Probed and initialized\n");
>
> - dev_dbg(dev, "(%s) Initialized\n", data->dbgname);
> - return 0;
> -err_irq:
> - while (i-- > 0) {
> - int irq;
> -
> - irq = platform_get_irq(pdev, i);
> - free_irq(irq, data);
> - }
> -err_res:
> - while (data->nsfrs-- > 0)
> - iounmap(data->sfrbases[data->nsfrs]);
> - kfree(data->sfrbases);
> -err_init:
> - kfree(data);
> -err_alloc:
> - dev_err(dev, "Failed to initialize\n");
> return ret;
> }
>
> -static struct platform_driver exynos_sysmmu_driver = {
> - .probe = exynos_sysmmu_probe,
> - .driver = {
> +#ifdef CONFIG_OF
> +static struct of_device_id sysmmu_of_match[] __initconst = {
> + { .compatible = "samsung,exynos4210-sysmmu", },
> + { },
> +};
> +#endif
> +
> +static struct platform_driver exynos_sysmmu_driver __refdata = {
> + .probe = exynos_sysmmu_probe,
> + .driver = {
> .owner = THIS_MODULE,
> .name = "exynos-sysmmu",
> + .of_match_table = of_match_ptr(sysmmu_of_match),
> }
> };
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