fpga: dfl: afu: add DFL_FPGA_PORT_DMA_MAP/UNMAP ioctls support

DMA memory regions are required for Accelerated Function Unit (AFU) usage.
These two ioctls allow user space applications to map user memory regions
for dma, and unmap them after use. Iova is returned from driver to user
space application via DFL_FPGA_PORT_DMA_MAP ioctl. Application needs to
unmap it after use, otherwise, driver will unmap them in device file
release operation.

Each AFU has its own rb tree to keep track of its mapped DMA regions.

Ioctl interfaces:
* DFL_FPGA_PORT_DMA_MAP
  Do the dma mapping per user_addr and length provided by user.
  Return iova in provided struct dfl_fpga_port_dma_map.

* DFL_FPGA_PORT_DMA_UNMAP
  Unmap the dma region per iova provided by user.

Signed-off-by: Tim Whisonant <tim.whisonant@intel.com>
Signed-off-by: Enno Luebbers <enno.luebbers@intel.com>
Signed-off-by: Shiva Rao <shiva.rao@intel.com>
Signed-off-by: Christopher Rauer <christopher.rauer@intel.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 60 insertions, 1 deletions

diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c
index f67a78d7e9ad..02baa6a227c0 100644
--- a/drivers/fpga/dfl-afu-main.c
+++ b/drivers/fpga/dfl-afu-main.c
@@ -293,7 +293,11 @@ static int afu_release(struct inode *inode, struct file *filp)
 
 	pdata = dev_get_platdata(&pdev->dev);
 
-	port_reset(pdev);
+	mutex_lock(&pdata->lock);
+	__port_reset(pdev);
+	afu_dma_region_destroy(pdata);
+	mutex_unlock(&pdata->lock);
+
 	dfl_feature_dev_use_end(pdata);
 
 	return 0;
@@ -364,6 +368,55 @@ static long afu_ioctl_get_region_info(struct dfl_feature_platform_data *pdata,
 	return 0;
 }
 
+static long
+afu_ioctl_dma_map(struct dfl_feature_platform_data *pdata, void __user *arg)
+{
+	struct dfl_fpga_port_dma_map map;
+	unsigned long minsz;
+	long ret;
+
+	minsz = offsetofend(struct dfl_fpga_port_dma_map, iova);
+
+	if (copy_from_user(&map, arg, minsz))
+		return -EFAULT;
+
+	if (map.argsz < minsz || map.flags)
+		return -EINVAL;
+
+	ret = afu_dma_map_region(pdata, map.user_addr, map.length, &map.iova);
+	if (ret)
+		return ret;
+
+	if (copy_to_user(arg, &map, sizeof(map))) {
+		afu_dma_unmap_region(pdata, map.iova);
+		return -EFAULT;
+	}
+
+	dev_dbg(&pdata->dev->dev, "dma map: ua=%llx, len=%llx, iova=%llx\n",
+		(unsigned long long)map.user_addr,
+		(unsigned long long)map.length,
+		(unsigned long long)map.iova);
+
+	return 0;
+}
+
+static long
+afu_ioctl_dma_unmap(struct dfl_feature_platform_data *pdata, void __user *arg)
+{
+	struct dfl_fpga_port_dma_unmap unmap;
+	unsigned long minsz;
+
+	minsz = offsetofend(struct dfl_fpga_port_dma_unmap, iova);
+
+	if (copy_from_user(&unmap, arg, minsz))
+		return -EFAULT;
+
+	if (unmap.argsz < minsz || unmap.flags)
+		return -EINVAL;
+
+	return afu_dma_unmap_region(pdata, unmap.iova);
+}
+
 static long afu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct platform_device *pdev = filp->private_data;
@@ -384,6 +437,10 @@ static long afu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return afu_ioctl_get_info(pdata, (void __user *)arg);
 	case DFL_FPGA_PORT_GET_REGION_INFO:
 		return afu_ioctl_get_region_info(pdata, (void __user *)arg);
+	case DFL_FPGA_PORT_DMA_MAP:
+		return afu_ioctl_dma_map(pdata, (void __user *)arg);
+	case DFL_FPGA_PORT_DMA_UNMAP:
+		return afu_ioctl_dma_unmap(pdata, (void __user *)arg);
 	default:
 		/*
 		 * Let sub-feature's ioctl function to handle the cmd
@@ -460,6 +517,7 @@ static int afu_dev_init(struct platform_device *pdev)
 	mutex_lock(&pdata->lock);
 	dfl_fpga_pdata_set_private(pdata, afu);
 	afu_mmio_region_init(pdata);
+	afu_dma_region_init(pdata);
 	mutex_unlock(&pdata->lock);
 
 	return 0;
@@ -473,6 +531,7 @@ static int afu_dev_destroy(struct platform_device *pdev)
 	mutex_lock(&pdata->lock);
 	afu = dfl_fpga_pdata_get_private(pdata);
 	afu_mmio_region_destroy(pdata);
+	afu_dma_region_destroy(pdata);
 	dfl_fpga_pdata_set_private(pdata, NULL);
 	mutex_unlock(&pdata->lock);