On 04/04/17 11:18, 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.
>
> This patch changes the dma ops configuration to probe time for
> both OF and ACPI based platform/amba/pci bus devices.
Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
It's possible we could subsume {of,acpi}_dma_deconfigure() into
dma_deconfigure() entirely in future if it becomes clear that neither of
them will ever need to do anything firmware-specific, but I think for
now it's probably safer to keep the current symmetry - calling
arch_teardown_dma_ops() twice is benign (and even if it weren't, I'd say
it really should be!)
Robin.
> Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> (drivers/pci part)
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Signed-off-by: Sricharan R <sricharan@xxxxxxxxxxxxxx>
> ---
>
> [V10] Added dummy dma_(de)configure functions in case
> of !CONFIG_HAS_DMA to avoid build breaks.
>
> drivers/acpi/glue.c | 5 -----
> drivers/base/dd.c | 9 +++++++++
> drivers/base/dma-mapping.c | 40 ++++++++++++++++++++++++++++++++++++++++
> drivers/of/platform.c | 5 +----
> drivers/pci/probe.c | 28 ----------------------------
> include/linux/dma-mapping.h | 12 ++++++++++++
> 6 files changed, 62 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
> index fb19e1c..c05f241 100644
> --- a/drivers/acpi/glue.c
> +++ b/drivers/acpi/glue.c
> @@ -176,7 +176,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
> struct list_head *physnode_list;
> unsigned int node_id;
> int retval = -EINVAL;
> - enum dev_dma_attr attr;
>
> if (has_acpi_companion(dev)) {
> if (acpi_dev) {
> @@ -233,10 +232,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
> if (!has_acpi_companion(dev))
> ACPI_COMPANION_SET(dev, acpi_dev);
>
> - attr = acpi_get_dma_attr(acpi_dev);
> - if (attr != DEV_DMA_NOT_SUPPORTED)
> - acpi_dma_configure(dev, attr);
> -
> acpi_physnode_link_name(physical_node_name, node_id);
> retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
> physical_node_name);
> 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..449b948 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -7,9 +7,11 @@
> * This file is released under the GPLv2.
> */
>
> +#include <linux/acpi.h>
> #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 +343,41 @@ 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 *bridge = NULL, *dma_dev = dev;
> + enum dev_dma_attr attr;
> +
> + if (dev_is_pci(dev)) {
> + bridge = pci_get_host_bridge_device(to_pci_dev(dev));
> + dma_dev = bridge;
> + if (IS_ENABLED(CONFIG_OF) && dma_dev->parent &&
> + dma_dev->parent->of_node)
> + dma_dev = dma_dev->parent;
> + }
> +
> + if (dma_dev->of_node) {
> + of_dma_configure(dev, dma_dev->of_node);
> + } else if (has_acpi_companion(dma_dev)) {
> + attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode));
> + if (attr != DEV_DMA_NOT_SUPPORTED)
> + acpi_dma_configure(dev, attr);
> + }
> +
> + if (bridge)
> + pci_put_host_bridge_device(bridge);
> +
> + return 0;
> +}
> +
> +void dma_deconfigure(struct device *dev)
> +{
> + of_dma_deconfigure(dev);
> + acpi_dma_deconfigure(dev);
> +}
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 5344db5..2aa4ebb 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 dfc9a27..5a8dd43 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1893,33 +1893,6 @@ static void pci_set_msi_domain(struct pci_dev *dev)
> dev_set_msi_domain(&dev->dev, d);
> }
>
> -/**
> - * pci_dma_configure - Setup DMA configuration
> - * @dev: ptr to pci_dev struct of the PCI device
> - *
> - * Function to update PCI devices's DMA configuration using the same
> - * info from the OF node or ACPI node of host bridge's parent (if any).
> - */
> -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)) {
> - struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
> - enum dev_dma_attr attr = acpi_get_dma_attr(adev);
> -
> - if (attr == DEV_DMA_NOT_SUPPORTED)
> - dev_warn(&dev->dev, "DMA not supported.\n");
> - else
> - acpi_dma_configure(&dev->dev, attr);
> - }
> -
> - pci_put_host_bridge_device(bridge);
> -}
> -
> void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
> {
> int ret;
> @@ -1933,7 +1906,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
> dev->dev.dma_mask = &dev->dma_mask;
> dev->dev.dma_parms = &dev->dma_parms;
> dev->dev.coherent_dma_mask = 0xffffffffull;
> - pci_dma_configure(dev);
>
> pci_set_dma_max_seg_size(dev, 65536);
> pci_set_dma_seg_boundary(dev, 0xffffffff);
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index 0977317..4f3eece 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -728,6 +728,18 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
> }
> #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
>
> +#ifdef CONFIG_HAS_DMA
> +int dma_configure(struct device *dev);
> +void dma_deconfigure(struct device *dev);
> +#else
> +static inline int dma_configure(struct device *dev)
> +{
> + return 0;
> +}
> +
> +static inline void dma_deconfigure(struct device *dev) {}
> +#endif
> +
> /*
> * Managed DMA API
> */
>
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