From: Li Chen <lchen@xxxxxxxxxxxxx> This sample driver shows how to build struct pages support to no-map rmem. Signed-off-by: Li Chen <lchen@xxxxxxxxxxxxx> Change-Id: Ie78494fa86fda40ceb73eab3b8ba505d0ad851a1 --- samples/Kconfig | 7 ++ samples/Makefile | 1 + samples/reserved_mem/Makefile | 2 + samples/reserved_mem/rmem_dio.c | 116 ++++++++++++++++++++++++++++++++ 4 files changed, 126 insertions(+) create mode 100755 samples/reserved_mem/Makefile create mode 100755 samples/reserved_mem/rmem_dio.c diff --git a/samples/Kconfig b/samples/Kconfig index b0503ef058d3..d83ba02ec215 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -6,6 +6,13 @@ menuconfig SAMPLES if SAMPLES +config RESERVED_MEM_DIO + tristate "Build example reserved mem dio support" + depends on OF_RESERVED_MEM_DIO_SUPPORT + help + Build kernel space sample module to show how to add struct + page and dio support to reserved memory. + config SAMPLE_AUXDISPLAY bool "auxdisplay sample" depends on CC_CAN_LINK diff --git a/samples/Makefile b/samples/Makefile index 087e0988ccc5..106a386869eb 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 # Makefile for Linux samples code +obj-$(CONFIG_RESERVED_MEM_DIO) += reserved_mem/ subdir-$(CONFIG_SAMPLE_AUXDISPLAY) += auxdisplay subdir-$(CONFIG_SAMPLE_ANDROID_BINDERFS) += binderfs obj-$(CONFIG_SAMPLE_CONFIGFS) += configfs/ diff --git a/samples/reserved_mem/Makefile b/samples/reserved_mem/Makefile new file mode 100755 index 000000000000..a4f5c8bc08dc --- /dev/null +++ b/samples/reserved_mem/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_RESERVED_MEM_DIO) += rmem_dio.o diff --git a/samples/reserved_mem/rmem_dio.c b/samples/reserved_mem/rmem_dio.c new file mode 100755 index 000000000000..ffb3395de63c --- /dev/null +++ b/samples/reserved_mem/rmem_dio.c @@ -0,0 +1,116 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Sample driver for reserved memory with struct page and dio support. + * + * wsps is abbr for with struct page support + * + * Copyright (C) 2022 Li Chen <lchen@xxxxxxxxxxxxx> + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/cdev.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/miscdevice.h> +#include <linux/of_reserved_mem.h> +#include <linux/platform_device.h> + +/* + * dts example + * rmem: rmem@1 { + * compatible = "shared-dma-pool"; + * no-map; + * size = <0x0 0x20000000>; + * }; + * perf { + * compatible = "example,rmem"; + * memory-region = <&rmem>; + * }; + */ + +static struct reserved_mem *rmem; + +static int rmem_wsps_open(struct inode *inode, struct file *filp) +{ + return 0; +} + +static int rmem_wsps_release(struct inode *inode, + struct file *filp) +{ + return 0; +} + +static int rmem_wsps_mmap(struct file *file, + struct vm_area_struct *vma) +{ + return reserved_mem_dio_mmap(file, vma, rmem); +} + +static const struct file_operations rmem_wsps_remap_ops = { + .owner = THIS_MODULE, + .open = rmem_wsps_open, + .release = rmem_wsps_release, + .mmap = rmem_wsps_mmap, +}; + +static struct miscdevice rmem_wsps_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "rmem_wsps", + .fops = &rmem_wsps_remap_ops, +}; + +static int rmem_wsps_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + void *vaddr; + int ret; + + ret = misc_register(&rmem_wsps_miscdev); + if (ret) { + dev_err(dev, "%s: misc_register failed, %d\n", __func__, ret); + return -ENODEV; + } + + rmem = get_reserved_mem_from_dev(dev); + if (!rmem) { + dev_err(dev, "%s: failed to find reserved\n", __func__); + return -ENODEV; + } + + vaddr = reserved_mem_memremap_pages(dev, rmem); + if (IS_ERR_OR_NULL(vaddr)) + return PTR_ERR(vaddr); + + return 0; +} + +static const struct of_device_id rmem_dio_match[] = { + { + .compatible = "example,rmem", + }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, rmem_dio_match); + +static struct platform_driver rmem_wsps_driver = { + .probe = rmem_wsps_probe, + .driver = { + .name = "rmem_wsps", + .of_match_table = rmem_dio_match, + }, +}; + +static int __init rmem_wsps_init(void) +{ + return platform_driver_register(&rmem_wsps_driver); +} + +module_init(rmem_wsps_init); +MODULE_LICENSE("GPL"); -- 2.25.1