From: Mikko Perttunen mperttunen@nvidia.com
The context bus is a "dummy" bus that contains struct devices that correspond to IOMMU contexts assigned through Host1x to processes.
Even when host1x itself is built as a module, the bus is registered in built-in code so that the built-in ARM SMMU driver is able to reference it.
Signed-off-by: Mikko Perttunen mperttunen@nvidia.com --- v4: * Export bus as GPL --- drivers/gpu/Makefile | 3 +-- drivers/gpu/host1x/Kconfig | 5 +++++ drivers/gpu/host1x/Makefile | 1 + drivers/gpu/host1x/context_bus.c | 31 ++++++++++++++++++++++++++++++ include/linux/host1x_context_bus.h | 15 +++++++++++++++ 5 files changed, 53 insertions(+), 2 deletions(-) create mode 100644 drivers/gpu/host1x/context_bus.c create mode 100644 include/linux/host1x_context_bus.h
diff --git a/drivers/gpu/Makefile b/drivers/gpu/Makefile index 835c88318cec..8997f0096545 100644 --- a/drivers/gpu/Makefile +++ b/drivers/gpu/Makefile @@ -2,7 +2,6 @@ # drm/tegra depends on host1x, so if both drivers are built-in care must be # taken to initialize them in the correct order. Link order is the only way # to ensure this currently. -obj-$(CONFIG_TEGRA_HOST1X) += host1x/ -obj-y += drm/ vga/ +obj-y += host1x/ drm/ vga/ obj-$(CONFIG_IMX_IPUV3_CORE) += ipu-v3/ obj-$(CONFIG_TRACE_GPU_MEM) += trace/ diff --git a/drivers/gpu/host1x/Kconfig b/drivers/gpu/host1x/Kconfig index 6815b4db17c1..1861a8180d3f 100644 --- a/drivers/gpu/host1x/Kconfig +++ b/drivers/gpu/host1x/Kconfig @@ -1,8 +1,13 @@ # SPDX-License-Identifier: GPL-2.0-only + +config TEGRA_HOST1X_CONTEXT_BUS + bool + config TEGRA_HOST1X tristate "NVIDIA Tegra host1x driver" depends on ARCH_TEGRA || (ARM && COMPILE_TEST) select DMA_SHARED_BUFFER + select TEGRA_HOST1X_CONTEXT_BUS select IOMMU_IOVA help Driver for the NVIDIA Tegra host1x hardware. diff --git a/drivers/gpu/host1x/Makefile b/drivers/gpu/host1x/Makefile index d2b6f7de0498..c891a3e33844 100644 --- a/drivers/gpu/host1x/Makefile +++ b/drivers/gpu/host1x/Makefile @@ -18,3 +18,4 @@ host1x-y = \ hw/host1x07.o
obj-$(CONFIG_TEGRA_HOST1X) += host1x.o +obj-$(CONFIG_TEGRA_HOST1X_CONTEXT_BUS) += context_bus.o diff --git a/drivers/gpu/host1x/context_bus.c b/drivers/gpu/host1x/context_bus.c new file mode 100644 index 000000000000..b0d35b2bbe89 --- /dev/null +++ b/drivers/gpu/host1x/context_bus.c @@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2021, NVIDIA Corporation. + */ + +#include <linux/device.h> +#include <linux/of.h> + +struct bus_type host1x_context_device_bus_type = { + .name = "host1x-context", +}; +EXPORT_SYMBOL_GPL(host1x_context_device_bus_type); + +static int __init host1x_context_device_bus_init(void) +{ + int err; + + if (!of_machine_is_compatible("nvidia,tegra186") && + !of_machine_is_compatible("nvidia,tegra194") && + !of_machine_is_compatible("nvidia,tegra234")) + return 0; + + err = bus_register(&host1x_context_device_bus_type); + if (err < 0) { + pr_err("bus type registration failed: %d\n", err); + return err; + } + + return 0; +} +postcore_initcall(host1x_context_device_bus_init); diff --git a/include/linux/host1x_context_bus.h b/include/linux/host1x_context_bus.h new file mode 100644 index 000000000000..72462737a6db --- /dev/null +++ b/include/linux/host1x_context_bus.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (c) 2021, NVIDIA Corporation. All rights reserved. + */ + +#ifndef __LINUX_HOST1X_CONTEXT_BUS_H +#define __LINUX_HOST1X_CONTEXT_BUS_H + +#include <linux/device.h> + +#ifdef CONFIG_TEGRA_HOST1X_CONTEXT_BUS +extern struct bus_type host1x_context_device_bus_type; +#endif + +#endif