dma-buf is designed to share buffers. Sharing means that there needs to
be another subsystem to accept those buffers. Introduce a simple test
module to act as a dummy system to accept dma_bufs from elsewhere. The
goal is to provide a very simple interface to validate exported buffers
do something reasonable. This is based on ion_test.c that existed for
the Ion framework.
Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx>
---
This is basically a drop in of what was available as
drivers/staging/android/ion/ion_test.c. Given it has no Ion specific
parts it might be useful as a more general test module. RFC mostly
to see if this is generally useful or not.
---
drivers/dma-buf/Kconfig | 9 ++
drivers/dma-buf/Makefile | 1 +
drivers/dma-buf/dma-buf-test.c | 309 ++++++++++++++++++++++++++++++++++++++
include/uapi/linux/dma_buf_test.h | 67 +++++++++
4 files changed, 386 insertions(+)
create mode 100644 drivers/dma-buf/dma-buf-test.c
create mode 100644 include/uapi/linux/dma_buf_test.h
diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig
index ed3b785..8b3fdb1 100644
--- a/drivers/dma-buf/Kconfig
+++ b/drivers/dma-buf/Kconfig
@@ -30,4 +30,13 @@ config SW_SYNC
WARNING: improper use of this can result in deadlocking kernel
drivers from userspace. Intended for test and debug only.
+config DMA_BUF_TEST
+ bool "Test module for dma-buf"
+ default n
+ ---help---
+ A test module to validate dma_buf APIs. This should not be
+ enabled for general use.
+
+ Say N here unless you know you want this.
+
endmenu
diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index c33bf88..5029608 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -1,3 +1,4 @@
obj-y := dma-buf.o dma-fence.o dma-fence-array.o reservation.o seqno-fence.o
obj-$(CONFIG_SYNC_FILE) += sync_file.o
obj-$(CONFIG_SW_SYNC) += sw_sync.o sync_debug.o
+obj-$(CONFIG_DMA_BUF_TEST) += dma-buf-test.o
diff --git a/drivers/dma-buf/dma-buf-test.c b/drivers/dma-buf/dma-buf-test.c
new file mode 100644
index 0000000..3af131c
--- /dev/null
+++ b/drivers/dma-buf/dma-buf-test.c
@@ -0,0 +1,309 @@
+/*
+ * Copyright (C) 2013 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License versdma_buf 2, as published by the Free Software Foundatdma_buf, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#define pr_fmt(fmt) "dma-buf-test: " fmt
+
+#include <linux/dma-buf.h>
+#include <linux/dma-direction.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+
+#include <uapi/linux/dma_buf_test.h>
+
+struct dma_buf_test_device {
+ struct miscdevice misc;
+};
+
+struct dma_buf_test_data {
+ struct dma_buf *dma_buf;
+ struct device *dev;
+};
+
+static int dma_buf_handle_test_dma(struct device *dev, struct dma_buf *dma_buf,
+ void __user *ptr, size_t offset, size_t size,
+ bool write)
+{
+ int ret = 0;
+ struct dma_buf_attachment *attach;
+ struct sg_table *table;
+ pgprot_t pgprot = pgprot_writecombine(PAGE_KERNEL);
+ enum dma_data_direction dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+ struct sg_page_iter sg_iter;
+ unsigned long offset_page;
+
+ attach = dma_buf_attach(dma_buf, dev);
+ if (IS_ERR(attach))
+ return PTR_ERR(attach);
+
+ table = dma_buf_map_attachment(attach, dir);
+ if (IS_ERR(table))
+ return PTR_ERR(table);
+
+ offset_page = offset >> PAGE_SHIFT;
+ offset %= PAGE_SIZE;
+
+ for_each_sg_page(table->sgl, &sg_iter, table->nents, offset_page) {
+ struct page *page = sg_page_iter_page(&sg_iter);
+ void *vaddr = vmap(&page, 1, VM_MAP, pgprot);
+ size_t to_copy = PAGE_SIZE - offset;
+
+ to_copy = min(to_copy, size);
+ if (!vaddr) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ if (write)
+ ret = copy_from_user(vaddr + offset, ptr, to_copy);
+ else
+ ret = copy_to_user(ptr, vaddr + offset, to_copy);
+
+ vunmap(vaddr);
+ if (ret) {
+ ret = -EFAULT;
+ goto err;
+ }
+ size -= to_copy;
+ if (!size)
+ break;
+ ptr += to_copy;
+ offset = 0;
+ }
+
+err:
+ dma_buf_unmap_attachment(attach, table, dir);
+ dma_buf_detach(dma_buf, attach);
+ return ret;
+}
+
+static int dma_buf_handle_test_kernel(struct dma_buf *dma_buf, void __user *ptr,
+ size_t offset, size_t size, bool write)
+{
+ int ret;
+ unsigned long page_offset = offset >> PAGE_SHIFT;
+ size_t copy_offset = offset % PAGE_SIZE;
+ size_t copy_size = size;
+ enum dma_data_direction dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+ if (offset > dma_buf->size || size > dma_buf->size - offset)
+ return -EINVAL;
+
+ ret = dma_buf_begin_cpu_access(dma_buf, dir);
+ if (ret)
+ return ret;
+
+ while (copy_size > 0) {
+ size_t to_copy;
+ void *vaddr = dma_buf_kmap(dma_buf, page_offset);
+
+ if (!vaddr)
+ goto err;
+
+ to_copy = min_t(size_t, PAGE_SIZE - copy_offset, copy_size);
+
+ if (write)
+ ret = copy_from_user(vaddr + copy_offset, ptr, to_copy);
+ else
+ ret = copy_to_user(ptr, vaddr + copy_offset, to_copy);
+
+ dma_buf_kunmap(dma_buf, page_offset, vaddr);
+ if (ret) {
+ ret = -EFAULT;
+ goto err;
+ }
+
+ copy_size -= to_copy;
+ ptr += to_copy;
+ page_offset++;
+ copy_offset = 0;
+ }
+err:
+ dma_buf_end_cpu_access(dma_buf, dir);
+ return ret;
+}
+
+static long dma_buf_test_ioctl(struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ struct dma_buf_test_data *test_data = filp->private_data;
+ int ret = 0;
+
+ union {
+ struct dma_buf_test_rw_data test_rw;
+ } data;
+
+ if (_IOC_SIZE(cmd) > sizeof(data))
+ return -EINVAL;
+
+ if (_IOC_DIR(cmd) & _IOC_WRITE)
+ if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
+ return -EFAULT;
+
+ switch (cmd) {
+ case DMA_BUF_IOC_TEST_SET_FD:
+ {
+ struct dma_buf *dma_buf = NULL;
+ int fd = arg;
+
+ if (fd >= 0) {
+ dma_buf = dma_buf_get((int)arg);
+ if (IS_ERR(dma_buf))
+ return PTR_ERR(dma_buf);
+ }
+ if (test_data->dma_buf)
+ dma_buf_put(test_data->dma_buf);
+ test_data->dma_buf = dma_buf;
+ break;
+ }
+ case DMA_BUF_IOC_TEST_DMA_MAPPING:
+ {
+ ret = dma_buf_handle_test_dma(test_data->dev,
+ test_data->dma_buf,
+ u64_to_user_ptr(data.test_rw.ptr),
+ data.test_rw.offset,
+ data.test_rw.size,
+ data.test_rw.write);
+ break;
+ }
+ case DMA_BUF_IOC_TEST_KERNEL_MAPPING:
+ {
+ ret = dma_buf_handle_test_kernel(test_data->dma_buf,
+ u64_to_user_ptr(data.test_rw.ptr),
+ data.test_rw.offset,
+ data.test_rw.size,
+ data.test_rw.write);
+ break;
+ }
+ default:
+ return -ENOTTY;
+ }
+
+ if (_IOC_DIR(cmd) & _IOC_READ) {
+ if (copy_to_user((void __user *)arg, &data, sizeof(data)))
+ return -EFAULT;
+ }
+ return ret;
+}
+
+static int dma_buf_test_open(struct inode *inode, struct file *file)
+{
+ struct dma_buf_test_data *data;
+ struct miscdevice *miscdev = file->private_data;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->dev = miscdev->parent;
+
+ file->private_data = data;
+
+ return 0;
+}
+
+static int dma_buf_test_release(struct inode *inode, struct file *file)
+{
+ struct dma_buf_test_data *data = file->private_data;
+
+ kfree(data);
+
+ return 0;
+}
+
+static const struct file_operations dma_buf_test_fops = {
+ .owner = THIS_MODULE,
+ .unlocked_ioctl = dma_buf_test_ioctl,
+ .compat_ioctl = dma_buf_test_ioctl,
+ .open = dma_buf_test_open,
+ .release = dma_buf_test_release,
+};
+
+static int __init dma_buf_test_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct dma_buf_test_device *testdev;
+
+ testdev = devm_kzalloc(&pdev->dev, sizeof(struct dma_buf_test_device),
+ GFP_KERNEL);
+ if (!testdev)
+ return -ENOMEM;
+
+ testdev->misc.minor = MISC_DYNAMIC_MINOR;
+ testdev->misc.name = "dma_buf-test";
+ testdev->misc.fops = &dma_buf_test_fops;
+ testdev->misc.parent = &pdev->dev;
+ /*
+ * We need to force 'something' for a DMA mask. This isn't an actual
+ * device and won't be doing actual DMA so pick 'something' that
+ * probably won't blow up. Probably.
+ */
+ dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+ ret = misc_register(&testdev->misc);
+ if (ret) {
+ pr_err("failed to register misc device.\n");
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, testdev);
+
+ return 0;
+}
+
+static int dma_buf_test_remove(struct platform_device *pdev)
+{
+ struct dma_buf_test_device *testdev;
+
+ testdev = platform_get_drvdata(pdev);
+ if (!testdev)
+ return -ENODATA;
+
+ misc_deregister(&testdev->misc);
+ return 0;
+}
+
+static struct platform_device *dma_buf_test_pdev;
+static struct platform_driver dma_buf_test_platform_driver = {
+ .remove = dma_buf_test_remove,
+ .driver = {
+ .name = "dma_buf-test",
+ },
+};
+
+static int __init dma_buf_test_init(void)
+{
+ dma_buf_test_pdev = platform_device_register_simple("dma-buf-test",
+ -1, NULL, 0);
+ if (IS_ERR(dma_buf_test_pdev))
+ return PTR_ERR(dma_buf_test_pdev);
+
+ return platform_driver_probe(&dma_buf_test_platform_driver,
+ dma_buf_test_probe);
+}
+
+static void __exit dma_buf_test_exit(void)
+{
+ platform_driver_unregister(&dma_buf_test_platform_driver);
+ platform_device_unregister(dma_buf_test_pdev);
+}
+
+module_init(dma_buf_test_init);
+module_exit(dma_buf_test_exit);
+MODULE_LICENSE("GPL v2");
diff --git a/include/uapi/linux/dma_buf_test.h b/include/uapi/linux/dma_buf_test.h
new file mode 100644
index 0000000..af2d521
--- /dev/null
+++ b/include/uapi/linux/dma_buf_test.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License versdma_buf 2, as published by the Free Software Foundatdma_buf, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _UAPI_LINUX_DMA_BUF_TEST_H
+#define _UAPI_LINUX_DMA_BUF_TEST_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/**
+ * struct dma_buf_test_rw_data - metadata passed to the kernel to read handle
+ * @ptr: a pointer to an area at least as large as size
+ * @offset: offset into the dma_buf buffer to start reading
+ * @size: size to read or write
+ * @write: 1 to write, 0 to read
+ */
+struct dma_buf_test_rw_data {
+ __u64 ptr;
+ __u64 offset;
+ __u64 size;
+ int write;
+ int __padding;
+};
+
+#define DMA_BUF_IOC_MAGIC 'I'
+
+/**
+ * DOC: DMA_BUF_IOC_TEST_SET_DMA_BUF - attach a dma buf to the test driver
+ *
+ * Attaches a dma buf fd to the test driver. Passing a second fd or -1 will
+ * release the first fd.
+ */
+#define DMA_BUF_IOC_TEST_SET_FD \
+ _IO(DMA_BUF_IOC_MAGIC, 0xf0)
+
+/**
+ * DOC: DMA_BUF_IOC_TEST_DMA_MAPPING - read or write memory from a handle as DMA
+ *
+ * Reads or writes the memory from a handle using an uncached mapping. Can be
+ * used by unit tests to emulate a DMA engine as close as possible. Only
+ * expected to be used for debugging and testing, may not always be available.
+ */
+#define DMA_BUF_IOC_TEST_DMA_MAPPING \
+ _IOW(DMA_BUF_IOC_MAGIC, 0xf1, struct dma_buf_test_rw_data)
+
+/**
+ * DOC: DMA_BUF_IOC_TEST_KERNEL_MAPPING - read or write memory from a handle
+ *
+ * Reads or writes the memory from a handle using a kernel mapping. Can be
+ * used by unit tests to test heap map_kernel functdma_bufs. Only expected to be
+ * used for debugging and testing, may not always be available.
+ */
+#define DMA_BUF_IOC_TEST_KERNEL_MAPPING \
+ _IOW(DMA_BUF_IOC_MAGIC, 0xf2, struct dma_buf_test_rw_data)
+
+#endif /* _UAPI_LINUX_DMA_BUF_TEST_H */
--
2.7.4
