[RFC][PATCH 5/6 v3] dma-buf: Add Dummy Importer Test Device
John Stultz
john.stultz at linaro.org
Fri Mar 29 00:16:01 UTC 2019
From: "Andrew F. Davis" <afd at ti.com>
This dummy test driver lets us do some very basic testing of
importing dma-bufs.
It is based originally on TI's out of tree "DMA-BUF physical
address user-space exporter" originally by
Andrew F. Davis <afd at ti.com>
Cc: Benjamin Gaignard <benjamin.gaignard at linaro.org>
Cc: Sumit Semwal <sumit.semwal at linaro.org>
Cc: Liam Mark <lmark at codeaurora.org>
Cc: Pratik Patel <pratikp at codeaurora.org>
Cc: Brian Starkey <Brian.Starkey at arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort at arm.com>
Cc: Sudipto Paul <Sudipto.Paul at arm.com>
Cc: Andrew F. Davis <afd at ti.com>
Cc: Xu YiPing <xuyiping at hisilicon.com>
Cc: "Chenfeng (puck)" <puck.chen at hisilicon.com>
Cc: butao <butao at hisilicon.com>
Cc: "Xiaqing (A)" <saberlily.xia at hisilicon.com>
Cc: Yudongbin <yudongbin at hisilicon.com>
Cc: Christoph Hellwig <hch at infradead.org>
Cc: Chenbo Feng <fengc at google.com>
Cc: Alistair Strachan <astrachan at google.com>
Cc: dri-devel at lists.freedesktop.org
Signed-off-by: Andrew F. Davis <afd at ti.com>
[Renamed and refactored dma_buf_phys driver, rewote commitlog]
Signed-off-by: John Stultz <john.stultz at linaro.org>
---
drivers/dma-buf/Kconfig | 6 +
drivers/dma-buf/Makefile | 1 +
drivers/dma-buf/dma-buf-testdev.c | 239 +++++++++++++++++++++++++++++++++++
include/uapi/linux/dma-buf-testdev.h | 37 ++++++
4 files changed, 283 insertions(+)
create mode 100644 drivers/dma-buf/dma-buf-testdev.c
create mode 100644 include/uapi/linux/dma-buf-testdev.h
diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig
index 63c139d..3cbcbe0 100644
--- a/drivers/dma-buf/Kconfig
+++ b/drivers/dma-buf/Kconfig
@@ -49,4 +49,10 @@ menuconfig DMABUF_HEAPS
source "drivers/dma-buf/heaps/Kconfig"
+config DMABUF_TESTDEV
+ bool "DMA-BUF Dummy Test Device"
+ depends on DMA_SHARED_BUFFER
+ help
+ This provides a dummy test device that can be used to test
+ importing dma-bufs.
endmenu
diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index 09c2f2d..69bf45d 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_DMABUF_HEAPS) += dma-heap.o
obj-$(CONFIG_SYNC_FILE) += sync_file.o
obj-$(CONFIG_SW_SYNC) += sw_sync.o sync_debug.o
obj-$(CONFIG_UDMABUF) += udmabuf.o
+obj-$(CONFIG_DMABUF_TESTDEV) += dma-buf-testdev.o
diff --git a/drivers/dma-buf/dma-buf-testdev.c b/drivers/dma-buf/dma-buf-testdev.c
new file mode 100644
index 0000000..dc3ed93
--- /dev/null
+++ b/drivers/dma-buf/dma-buf-testdev.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMA-BUF Dummy Importer Test Device
+ *
+ * Originally from TI DMA BUF contiguous buffer physical address
+ * user-space exporter
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ * Andrew F. Davis <afd at ti.com>
+ */
+
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include <uapi/linux/dma-buf-testdev.h>
+
+#define DEVICE_NAME "dma-buf-testdev"
+
+struct dma_buf_testdev_priv {
+ struct miscdevice miscdev;
+};
+
+struct dma_buf_testdev_file {
+ struct device *dev;
+ struct dma_buf *dma_buf;
+ struct dma_buf_attachment *attachment;
+ struct sg_table *sgt;
+};
+
+static int dma_buf_testdev_open(struct inode *inode, struct file *file)
+{
+ struct miscdevice *miscdev = file->private_data;
+ struct device *dev = miscdev->this_device;
+ struct dma_buf_testdev_file *priv;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ priv->dev = dev;
+ file->private_data = (void *)priv;
+
+ return 0;
+}
+
+static int dma_buf_testdev_release(struct inode *inode, struct file *file)
+{
+ struct dma_buf_testdev_file *priv = file->private_data;
+
+ if (priv->attachment && priv->sgt)
+ dma_buf_unmap_attachment(priv->attachment, priv->sgt,
+ DMA_BIDIRECTIONAL);
+ if (priv->dma_buf && priv->attachment)
+ dma_buf_detach(priv->dma_buf, priv->attachment);
+ if (priv->dma_buf)
+ dma_buf_put(priv->dma_buf);
+
+ kfree(priv);
+
+ return 0;
+}
+
+static int dma_buf_testdev_convert(struct dma_buf_testdev_file *priv, int fd,
+ phys_addr_t *phys)
+{
+ struct device *dev = priv->dev;
+ struct dma_buf *dma_buf;
+ struct dma_buf_attachment *attachment;
+ struct sg_table *sgt;
+ dma_addr_t dma_addr;
+ int ret;
+
+ dma_buf = dma_buf_get(fd);
+ if (IS_ERR(dma_buf))
+ return PTR_ERR(dma_buf);
+
+ /* Attach as the parent device as it will have the correct DMA ops */
+ attachment = dma_buf_attach(dma_buf, dev->parent);
+ if (IS_ERR(attachment)) {
+ ret = PTR_ERR(attachment);
+ goto fail_put;
+ }
+
+ sgt = dma_buf_map_attachment(attachment, DMA_BIDIRECTIONAL);
+ if (IS_ERR(sgt)) {
+ ret = PTR_ERR(sgt);
+ goto fail_detach;
+ }
+
+ /* Without PAT only physically contiguous buffers can be supported */
+ if (sgt->orig_nents != 1) {
+ dev_err(dev, "DMA-BUF not contiguous\n");
+ ret = -EINVAL;
+ goto fail_unmap;
+ }
+
+ dma_addr = sg_dma_address(sgt->sgl);
+
+ *phys = dma_addr;
+
+ priv->dma_buf = dma_buf;
+ priv->attachment = attachment;
+ priv->sgt = sgt;
+
+ return 0;
+
+fail_unmap:
+ dma_buf_unmap_attachment(attachment, sgt, DMA_BIDIRECTIONAL);
+fail_detach:
+ dma_buf_detach(dma_buf, attachment);
+fail_put:
+ dma_buf_put(dma_buf);
+
+ return ret;
+}
+
+static long dma_buf_testdev_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct dma_buf_testdev_file *priv = file->private_data;
+
+ switch (cmd) {
+ case DMA_BUF_TESTDEV_IOC_CONVERT:
+ {
+ struct dma_buf_testdev_data data;
+ int ret;
+
+ /*
+ * TODO: this should likely be properly serialized, but I
+ * see no reason this file would ever need to be shared.
+ */
+ /* one attachment per file */
+ if (priv->dma_buf)
+ return -EFAULT;
+
+ if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
+ return -EFAULT;
+
+ ret = dma_buf_testdev_convert(priv, data.fd, &data.phys);
+ if (ret)
+ return ret;
+
+ if (copy_to_user((void __user *)arg, &data, _IOC_SIZE(cmd)))
+ return -EFAULT;
+
+ break;
+ }
+ default:
+ return -ENOTTY;
+ }
+
+ return 0;
+}
+
+static const struct file_operations dma_buf_testdev_fops = {
+ .owner = THIS_MODULE,
+ .open = dma_buf_testdev_open,
+ .release = dma_buf_testdev_release,
+ .unlocked_ioctl = dma_buf_testdev_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = dma_buf_testdev_ioctl,
+#endif
+};
+
+static int dma_buf_testdev_probe(struct platform_device *pdev)
+{
+ struct dma_buf_testdev_priv *priv;
+ struct device *dev = &pdev->dev;
+ int err;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ dev_set_drvdata(dev, priv);
+
+ dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
+
+ if (!dev->dma_parms) {
+ dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
+ GFP_KERNEL);
+ if (!dev->dma_parms)
+ return -ENOMEM;
+ }
+ dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
+
+ priv->miscdev.minor = MISC_DYNAMIC_MINOR;
+ priv->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s",
+ DEVICE_NAME);
+ priv->miscdev.fops = &dma_buf_testdev_fops;
+ priv->miscdev.parent = dev;
+ err = misc_register(&priv->miscdev);
+ if (err) {
+ dev_err(dev,
+ "unable to register DMA-BUF to Phys misc device\n");
+ return err;
+ }
+
+ return 0;
+}
+
+static int dma_buf_testdev_remove(struct platform_device *pdev)
+{
+ struct dma_buf_testdev_priv *priv = dev_get_drvdata(&pdev->dev);
+
+ misc_deregister(&priv->miscdev);
+
+ return 0;
+}
+
+static struct platform_driver dma_buf_testdev_driver = {
+ .probe = dma_buf_testdev_probe,
+ .remove = dma_buf_testdev_remove,
+ .driver = {
+ .name = "dma_buf_testdev",
+ }
+};
+module_platform_driver(dma_buf_testdev_driver);
+
+static int __init dma_buf_testdev_init(void)
+{
+ struct platform_device *pdev;
+
+ pdev = platform_device_register_simple("dma_buf_testdev", -1, NULL, 0);
+
+ return PTR_ERR_OR_ZERO(pdev);
+}
+
+postcore_initcall(dma_buf_testdev_init);
+
+MODULE_AUTHOR("Andrew F. Davis <afd at ti.com>");
+MODULE_DESCRIPTION("DMA-BUF Dummy Importer Test Device");
+MODULE_LICENSE("GPL v2");
diff --git a/include/uapi/linux/dma-buf-testdev.h b/include/uapi/linux/dma-buf-testdev.h
new file mode 100644
index 0000000..b9706b8
--- /dev/null
+++ b/include/uapi/linux/dma-buf-testdev.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * DMA-BUF Dummy Importer Test Device
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ * Andrew F. Davis <afd at ti.com>
+ */
+
+#ifndef DMA_BUF_TESTDEV_H
+#define DMA_BUF_TESTDEV_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/**
+ * struct dma_buf_testdev_data - metadata passed from userspace for conversion
+ * @fd: DMA-BUF fd for conversion
+ * @phys: populated with CPU physical address of DMA-BUF
+ */
+struct dma_buf_testdev_data {
+ __u32 fd;
+ __u64 phys;
+};
+
+#define DMA_BUF_TESTDEV_IOC_MAGIC 'D'
+
+/**
+ * DOC: DMA_BUF_TESTDEV_IOC_CONVERT - Convert DMA-BUF to physical address
+ *
+ * Takes a dma_buf_testdev_data struct containing a fd for a
+ * physicaly contigous buffer. Pins this buffer and populates
+ * phys field with the CPU physical address.
+ */
+#define DMA_BUF_TESTDEV_IOC_CONVERT _IOWR(DMA_BUF_TESTDEV_IOC_MAGIC, 0, \
+ struct dma_buf_testdev_data)
+
+#endif /* DMA_BUF_PHYS_H */
--
2.7.4
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