On Wed, Nov 28, 2012 at 02:48:32PM +0100, Hiroshi Doyu wrote:
[...]
> From: Hiroshi Doyu <hdoyu@xxxxxxxxxx>
> Date: Wed, 28 Nov 2012 14:47:04 +0200
> Subject: [PATCH 1/1] ARM: tegra: bus_notifier registers IOMMU devices
>
> platform_bus notifier registers IOMMU devices if dma-window is
> specified.
>
> Its format is:
> dma-window = <"start" "size">;
> ex)
> dma-window = <0x12345000 0x8000>;
>
> Signed-off-by: Hiroshi Doyu <hdoyu@xxxxxxxxxx>
> ---
> arch/arm/mach-tegra/board-dt-tegra30.c | 40 ++++++++++++++++++++++++++++++++
> 1 file changed, 40 insertions(+)
>
> diff --git a/arch/arm/mach-tegra/board-dt-tegra30.c b/arch/arm/mach-tegra/board-dt-tegra30.c
> index a2b6cf1..570d718 100644
> --- a/arch/arm/mach-tegra/board-dt-tegra30.c
> +++ b/arch/arm/mach-tegra/board-dt-tegra30.c
> @@ -30,9 +30,11 @@
> #include <linux/of_fdt.h>
> #include <linux/of_irq.h>
> #include <linux/of_platform.h>
> +#include <linux/of_iommu.h>
>
> #include <asm/mach/arch.h>
> #include <asm/hardware/gic.h>
> +#include <asm/dma-iommu.h>
>
> #include "board.h"
> #include "clock.h"
> @@ -86,10 +88,48 @@ static __initdata struct tegra_clk_init_table tegra_dt_clk_init_table[] = {
> { NULL, NULL, 0, 0},
> };
>
> +#ifdef CONFIG_ARM_DMA_USE_IOMMU
> +static int tegra_iommu_device_notifier(struct notifier_block *nb,
> + unsigned long event, void *_dev)
> +{
> + struct dma_iommu_mapping *map = NULL;
> + struct device *dev = _dev;
> + dma_addr_t base;
> + size_t size;
> + int err;
> +
> + switch (event) {
> + case BUS_NOTIFY_ADD_DEVICE:
> + err = of_get_dma_window(dev->of_node, NULL, 0, NULL, &base,
> + &size);
> + if (!err)
> + map = arm_iommu_create_mapping(&platform_bus_type,
> + base, size, 0);
> + if (IS_ERR_OR_NULL(map))
> + break;
> + if (arm_iommu_attach_device(dev, map))
> + dev_err(dev, "Failed to attach %s\n", dev_name(dev));
> + dev_dbg(dev, "Attached %s to map %p\n", dev_name(dev), map);
> + break;
> + }
> + return NOTIFY_DONE;
> +}
> +#else
> +#define tegra_iommu_device_notifier NULL
> +#endif
> +
> +static struct notifier_block tegra_iommu_device_nb = {
> + .notifier_call = tegra_iommu_device_notifier,
> +};
You don't need this extra protection since you use IS_ENABLED below and
these are all static variables. The whole point of IS_ENABLED is to
allow full compile coverage while leaving it up to the compiler to
eliminate dead code.
Thierry
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