On Thu, Jan 19, 2017 at 08:35:49PM +0530, Sricharan R wrote:
> Configuring DMA ops at probe time will allow deferring device probe when
> the IOMMU isn't available yet. The dma_configure for the device is
> now called from the generic device_attach callback just before the
> bus/driver probe is called. This way, configuring the DMA ops for the
> device would be called at the same place for all bus_types, hence the
> deferred probing mechanism should work for all buses as well.
>
> pci_bus_add_devices (platform/amba)(_device_create/driver_register)
> | |
> pci_bus_add_device (device_add/driver_register)
> | |
> device_attach device_initial_probe
> | |
> __device_attach_driver __device_attach_driver
> |
> driver_probe_device
> |
> really_probe
> |
> dma_configure
>
> Similarly on the device/driver_unregister path __device_release_driver is
> called which inturn calls dma_deconfigure.
>
> Signed-off-by: Sricharan R <sricha...@codeaurora.org>
> ---
> * Removed the dma configuration for the pci devices in case of DT
> from pci_dma_configure which was hanging outside separately and
> doing it in dma_configure function itself.
Rename the patch subject then, it is misleading.
Thanks,
Lorenzo
> drivers/base/dd.c | 9 +++++++++
> drivers/base/dma-mapping.c | 32 ++++++++++++++++++++++++++++++++
> drivers/of/platform.c | 5 +----
> drivers/pci/probe.c | 5 +----
> include/linux/dma-mapping.h | 3 +++
> 5 files changed, 46 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index a1fbf55..4882f06 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -19,6 +19,7 @@
>
> #include <linux/device.h>
> #include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> #include <linux/module.h>
> #include <linux/kthread.h>
> #include <linux/wait.h>
> @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct
> device_driver *drv)
> if (ret)
> goto pinctrl_bind_failed;
>
> + ret = dma_configure(dev);
> + if (ret)
> + goto dma_failed;
> +
> if (driver_sysfs_add(dev)) {
> printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
> __func__, dev_name(dev));
> @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct
> device_driver *drv)
> goto done;
>
> probe_failed:
> + dma_deconfigure(dev);
> +dma_failed:
> if (dev->bus)
> blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
> BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
> @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev,
> struct device *parent)
> drv->remove(dev);
>
> device_links_driver_cleanup(dev);
> + dma_deconfigure(dev);
> +
> devres_release_all(dev);
> dev->driver = NULL;
> dev_set_drvdata(dev, NULL);
> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> index efd71cf..dfe6fd7 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -10,6 +10,7 @@
> #include <linux/dma-mapping.h>
> #include <linux/export.h>
> #include <linux/gfp.h>
> +#include <linux/of_device.h>
> #include <linux/slab.h>
> #include <linux/vmalloc.h>
>
> @@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size,
> unsigned long vm_flags)
> vunmap(cpu_addr);
> }
> #endif
> +
> +/*
> + * Common configuration to enable DMA API use for a device
> + */
> +#include <linux/pci.h>
> +
> +int dma_configure(struct device *dev)
> +{
> + struct device *_dev = dev;
> + int is_pci = dev_is_pci(dev);
> +
> + if (is_pci) {
> + _dev = pci_get_host_bridge_device(to_pci_dev(dev));
> + if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
> + _dev->parent->of_node)
> + _dev = _dev->parent;
> + }
> +
> + if (_dev->of_node)
> + of_dma_configure(dev, _dev->of_node);
> +
> + if (is_pci)
> + pci_put_host_bridge_device(_dev);
> +
> + return 0;
> +}
> +
> +void dma_deconfigure(struct device *dev)
> +{
> + of_dma_deconfigure(dev);
> +}
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 57418f7..cf35030 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -22,6 +22,7 @@
> #include <linux/slab.h>
> #include <linux/of_address.h>
> #include <linux/of_device.h>
> +#include <linux/of_iommu.h>
> #include <linux/of_irq.h>
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> @@ -186,11 +187,9 @@ static struct platform_device
> *of_platform_device_create_pdata(
>
> dev->dev.bus = &platform_bus_type;
> dev->dev.platform_data = platform_data;
> - of_dma_configure(&dev->dev, dev->dev.of_node);
> of_msi_configure(&dev->dev, dev->dev.of_node);
>
> if (of_device_add(dev) != 0) {
> - of_dma_deconfigure(&dev->dev);
> platform_device_put(dev);
> goto err_clear_flag;
> }
> @@ -248,7 +247,6 @@ static struct amba_device *of_amba_device_create(struct
> device_node *node,
> dev_set_name(&dev->dev, "%s", bus_id);
> else
> of_device_make_bus_id(&dev->dev);
> - of_dma_configure(&dev->dev, dev->dev.of_node);
>
> /* Allow the HW Peripheral ID to be overridden */
> prop = of_get_property(node, "arm,primecell-periphid", NULL);
> @@ -542,7 +540,6 @@ static int of_platform_device_destroy(struct device *dev,
> void *data)
> amba_device_unregister(to_amba_device(dev));
> #endif
>
> - of_dma_deconfigure(dev);
> of_node_clear_flag(dev->of_node, OF_POPULATED);
> of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
> return 0;
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index e164b5c..634d34e 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1873,10 +1873,7 @@ static void pci_dma_configure(struct pci_dev *dev)
> {
> struct device *bridge = pci_get_host_bridge_device(dev);
>
> - if (IS_ENABLED(CONFIG_OF) &&
> - bridge->parent && bridge->parent->of_node) {
> - of_dma_configure(&dev->dev, bridge->parent->of_node);
> - } else if (has_acpi_companion(bridge)) {
> + if (has_acpi_companion(bridge)) {
> struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
> enum dev_dma_attr attr = acpi_get_dma_attr(adev);
>
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index abf685ed..b56320a 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -718,6 +718,9 @@ void *dma_mark_declared_memory_occupied(struct device
> *dev,
> }
> #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
>
> +int dma_configure(struct device *dev);
> +void dma_deconfigure(struct device *dev);
> +
> /*
> * Managed DMA API
> */
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of
> Code Aurora Forum, hosted by The Linux Foundation
>
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