On Fri, 09 Aug 2013 10:30:11 +0200, Tomasz Figa wrote: > On Friday 09 of August 2013 15:37:30 Cho KyongHo wrote: > > On Fri, 09 Aug 2013 00:41:25 +0200, Tomasz Figa wrote: > > > 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... > > > > Ok. > > > > > 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. > > > > Oh, I didn't know that devicetree binding description and implementation > > need to be in the same patch. > > I will do as you advised. > > Thanks. We are still missing a "best practices" document about device tree > binding development, so it might not be clear. > I saw Rob Herring has different idea about the seperation of patches. Let's talk about it more. > > > > 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. > > > > Ok. > > > > > > + 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. > > Let me show some example. > > FIMD in Exynos5250 has a single System MMU. > > FIMD in Exynos5420 has 2 System MMUs. > > I wanted to show the FIMD driver the same view of System MMU. > > Otherwise, FIMD driver must aware of how the System MMUs are connected > > with FIMD. > > > > If it is responsible for the device drivers of master H/Ws, System MMU > > driver can be much more simpler which I also prefer :) > > Yes, it is responsibility of FIMD driver to add all its IOMMUs into the > same domain or into any other configuration it wants. > > For example by some extension, the driver might want to have separate > address spaces for each IOMMU and this would not be possible with current > configuration of SysMMU driver. > Ok. I will post seperate series of patches for this issue later. I think it is better to discuss because it is change in design. > > > > - 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(). > > > > Oh. Thanks. > > > > > > if (!data->sfrbases[i]) { > > > > > > In case of devm_ioremap_resource() remember to adjust this check to > > > check for IS_ERR, not for NULL. > > > > Ok. Thanks. > > > > > > - 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. > > > > Ok. > > > > > > + 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. > > > > Error returned by devm_clk_get("sysmmu") is not an error actually. > > More specifically, -ENOENT returned by devm_clk_get("sysmmu") is not an > > error. It just means that a System MMU does not have to gating its > > clock. However, it is required to check if the error retruned is > > -ENOENT. > > I agree with this. Since the clock is optional for this driver, the - > ENOENT error case is not an error for it. > > > data->clk must be NULL if 'sysmmu' clock is not specified for a System > > MMU because clk_enable(data->clk) is called regardless of the value in > > data->clk. > > Still, the return value convention for Common Clock Framework is that > clk_get() can return a NULL and the driver must interpret this as a valid > clock handle (for a dummy clock for example) that can be passed to further > clock operations, such as clk_prepare() or clk_enable(). > > This is why the driver should not reserve NULL as its own value meaning > that the clock is not present, but should rather check for IS_ERR > everywhere to find out whether the clock was acquired at probe. > > Separate patch fixing this would be nice. > Ok. I understand that it must not be assumed that NULL as the arguement of clk_enable()/prepare() is ignored. I will change this patch not to call clk_enable/disable if IS_ERR(data->clk) is true. Thank you. > > Thank you for review :) > > You're welcome. Thank you for your work on this series. :) > > Best regards, > Tomasz > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html