Re: [PATCH v3 2/2] drivers: remove force dma flag from buses

From: Bjorn Helgaas
Date: Tue Apr 10 2018 - 15:22:02 EST


On Fri, Mar 30, 2018 at 01:24:45PM +0530, Nipun Gupta wrote:
> With each bus implementing its own DMA configuration callback,
> there is no need for bus to explicitly have force_dma in its
> global structure. This patch modifies of_dma_configure API to
> accept an input parameter which specifies if implicit DMA
> configuration is required even when it is not described by the
> firmware.
>
> Signed-off-by: Nipun Gupta <nipun.gupta@xxxxxxx>

Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> # PCI parts

> ---
> Changes in v2:
> - This is a new change suggested by Robin and Christoph
> and is added to the series.
>
> Changes in v3:
> - Rebase and changes corresponding to the changes in patch 1/2
>
> drivers/amba/bus.c | 1 -
> drivers/base/platform.c | 3 +--
> drivers/bcma/main.c | 2 +-
> drivers/dma/qcom/hidma_mgmt.c | 2 +-
> drivers/gpu/host1x/bus.c | 5 ++---
> drivers/of/device.c | 6 ++++--
> drivers/of/of_reserved_mem.c | 2 +-
> drivers/pci/pci-driver.c | 3 +--
> include/linux/device.h | 4 ----
> include/linux/of_device.h | 8 ++++++--
> 10 files changed, 17 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
> index 867dc2b..abe73c4 100644
> --- a/drivers/amba/bus.c
> +++ b/drivers/amba/bus.c
> @@ -199,7 +199,6 @@ struct bus_type amba_bustype = {
> .uevent = amba_uevent,
> .dma_configure = platform_dma_configure,
> .pm = &amba_pm,
> - .force_dma = true,
> };
>
> static int __init amba_init(void)
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index 72fdbf6..cfbc569 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -1136,7 +1136,7 @@ int platform_dma_configure(struct device *dev)
> int ret = 0;
>
> if (dev->of_node) {
> - ret = of_dma_configure(dev, dev->of_node);
> + ret = of_dma_configure(dev, dev->of_node, true);
> } else if (has_acpi_companion(dev)) {
> attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
> if (attr != DEV_DMA_NOT_SUPPORTED)
> @@ -1159,7 +1159,6 @@ struct bus_type platform_bus_type = {
> .uevent = platform_uevent,
> .dma_configure = platform_dma_configure,
> .pm = &platform_dev_pm_ops,
> - .force_dma = true,
> };
> EXPORT_SYMBOL_GPL(platform_bus_type);
>
> diff --git a/drivers/bcma/main.c b/drivers/bcma/main.c
> index e6986c7..fc1f4ac 100644
> --- a/drivers/bcma/main.c
> +++ b/drivers/bcma/main.c
> @@ -207,7 +207,7 @@ static void bcma_of_fill_device(struct device *parent,
>
> core->irq = bcma_of_get_irq(parent, core, 0);
>
> - of_dma_configure(&core->dev, node);
> + of_dma_configure(&core->dev, node, false);
> }
>
> unsigned int bcma_core_irq(struct bcma_device *core, int num)
> diff --git a/drivers/dma/qcom/hidma_mgmt.c b/drivers/dma/qcom/hidma_mgmt.c
> index 000c7019..d64edeb 100644
> --- a/drivers/dma/qcom/hidma_mgmt.c
> +++ b/drivers/dma/qcom/hidma_mgmt.c
> @@ -398,7 +398,7 @@ static int __init hidma_mgmt_of_populate_channels(struct device_node *np)
> }
> of_node_get(child);
> new_pdev->dev.of_node = child;
> - of_dma_configure(&new_pdev->dev, child);
> + of_dma_configure(&new_pdev->dev, child, true);
> /*
> * It is assumed that calling of_msi_configure is safe on
> * platforms with or without MSI support.
> diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c
> index a9ec99d..b39c1e9 100644
> --- a/drivers/gpu/host1x/bus.c
> +++ b/drivers/gpu/host1x/bus.c
> @@ -317,7 +317,7 @@ static int host1x_device_match(struct device *dev, struct device_driver *drv)
> static int host1x_dma_configure(struct device *dev)
> {
> if (dev->of_node)
> - return of_dma_configure(dev, dev->of_node);
> + return of_dma_configure(dev, dev->of_node, true);
> return 0;
> }
>
> @@ -335,7 +335,6 @@ struct bus_type host1x_bus_type = {
> .match = host1x_device_match,
> .dma_configure = host1x_dma_configure,
> .pm = &host1x_device_pm_ops,
> - .force_dma = true,
> };
>
> static void __host1x_device_del(struct host1x_device *device)
> @@ -424,7 +423,7 @@ static int host1x_device_add(struct host1x *host1x,
> device->dev.bus = &host1x_bus_type;
> device->dev.parent = host1x->dev;
>
> - of_dma_configure(&device->dev, host1x->dev->of_node);
> + of_dma_configure(&device->dev, host1x->dev->of_node, true);
>
> err = host1x_device_parse_dt(device, driver);
> if (err < 0) {
> diff --git a/drivers/of/device.c b/drivers/of/device.c
> index 064c818..33d8551 100644
> --- a/drivers/of/device.c
> +++ b/drivers/of/device.c
> @@ -76,6 +76,8 @@ int of_device_add(struct platform_device *ofdev)
> * of_dma_configure - Setup DMA configuration
> * @dev: Device to apply DMA configuration
> * @np: Pointer to OF node having DMA configuration
> + * @force_dma: Whether device is to be set up by of_dma_configure() even if
> + * DMA capability is not explicitly described by firmware.
> *
> * Try to get devices's DMA configuration from DT and update it
> * accordingly.
> @@ -84,7 +86,7 @@ int of_device_add(struct platform_device *ofdev)
> * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
> * to fix up DMA configuration.
> */
> -int of_dma_configure(struct device *dev, struct device_node *np)
> +int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
> {
> u64 dma_addr, paddr, size = 0;
> int ret;
> @@ -100,7 +102,7 @@ int of_dma_configure(struct device *dev, struct device_node *np)
> * DMA configuration regardless of whether "dma-ranges" is
> * correctly specified or not.
> */
> - if (!dev->bus->force_dma)
> + if (!force_dma)
> return ret == -ENODEV ? 0 : ret;
>
> dma_addr = offset = 0;
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> index 9a4f4246..895c83e 100644
> --- a/drivers/of/of_reserved_mem.c
> +++ b/drivers/of/of_reserved_mem.c
> @@ -353,7 +353,7 @@ int of_reserved_mem_device_init_by_idx(struct device *dev,
> /* ensure that dma_ops is set for virtual devices
> * using reserved memory
> */
> - of_dma_configure(dev, np);
> + of_dma_configure(dev, np, true);
>
> dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
> } else {
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 78e507f..27c832f 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -1540,7 +1540,7 @@ static int pci_dma_configure(struct device *dev)
>
> if (IS_ENABLED(CONFIG_OF) && bridge->parent &&
> bridge->parent->of_node) {
> - ret = of_dma_configure(dev, bridge->parent->of_node);
> + ret = of_dma_configure(dev, bridge->parent->of_node, true);
> } 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);
> @@ -1566,7 +1566,6 @@ struct bus_type pci_bus_type = {
> .pm = PCI_PM_OPS_PTR,
> .num_vf = pci_bus_num_vf,
> .dma_configure = pci_dma_configure,
> - .force_dma = true,
> };
> EXPORT_SYMBOL(pci_bus_type);
>
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 1832d90..92c530e 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -98,8 +98,6 @@ extern int __must_check bus_create_file(struct bus_type *,
> * @p: The private data of the driver core, only the driver core can
> * touch this.
> * @lock_key: Lock class key for use by the lock validator
> - * @force_dma: Assume devices on this bus should be set up by dma_configure()
> - * even if DMA capability is not explicitly described by firmware.
> *
> * A bus is a channel between the processor and one or more devices. For the
> * purposes of the device model, all devices are connected via a bus, even if
> @@ -140,8 +138,6 @@ struct bus_type {
>
> struct subsys_private *p;
> struct lock_class_key lock_key;
> -
> - bool force_dma;
> };
>
> extern int __must_check bus_register(struct bus_type *bus);
> diff --git a/include/linux/of_device.h b/include/linux/of_device.h
> index 8da5a1b..165fd30 100644
> --- a/include/linux/of_device.h
> +++ b/include/linux/of_device.h
> @@ -55,7 +55,9 @@ static inline struct device_node *of_cpu_device_node_get(int cpu)
> return of_node_get(cpu_dev->of_node);
> }
>
> -int of_dma_configure(struct device *dev, struct device_node *np);
> +int of_dma_configure(struct device *dev,
> + struct device_node *np,
> + bool force_dma);
> void of_dma_deconfigure(struct device *dev);
> #else /* CONFIG_OF */
>
> @@ -105,7 +107,9 @@ static inline struct device_node *of_cpu_device_node_get(int cpu)
> return NULL;
> }
>
> -static inline int of_dma_configure(struct device *dev, struct device_node *np)
> +static inline int of_dma_configure(struct device *dev,
> + struct device_node *np,
> + bool force_dma)
> {
> return 0;
> }
> --
> 1.9.1
>