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
