1 files changed, 309 insertions, 0 deletions
diff --git a/kernel/ethosu_buffer.c b/kernel/ethosu_buffer.c
new file mode 100644
index 0000000..bcc7242
--- /dev/null
+++ b/kernel/ethosu_buffer.c
@@ -0,0 +1,309 @@
+/*
+ * (C) COPYRIGHT 2020 ARM Limited. All rights reserved.
+ *
+ * This program is free software and is provided to you under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation, and any use by you of this program is subject to the terms
+ * of such GNU licence.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ */
+
+/****************************************************************************
+ * Includes
+ ****************************************************************************/
+
+#include "ethosu_buffer.h"
+
+#include "ethosu_device.h"
+#include "uapi/ethosu.h"
+
+#include <linux/anon_inodes.h>
+#include <linux/dma-mapping.h>
+#include <linux/of_address.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+
+/****************************************************************************
+ * Variables
+ ****************************************************************************/
+
+static int ethosu_buffer_release(struct inode *inode,
+				 struct file *file);
+
+static int ethosu_buffer_mmap(struct file *file,
+			      struct vm_area_struct *vma);
+
+static long ethosu_buffer_ioctl(struct file *file,
+				unsigned int cmd,
+				unsigned long arg);
+
+static const struct file_operations ethosu_buffer_fops = {
+	.release        = &ethosu_buffer_release,
+	.mmap           = &ethosu_buffer_mmap,
+	.unlocked_ioctl = &ethosu_buffer_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = &ethosu_buffer_ioctl,
+#endif
+};
+
+/****************************************************************************
+ * Functions
+ ****************************************************************************/
+
+/*
+ * The 'dma-ranges' device tree property for shared dma memory does not seem
+ * to be fully supported for coherent memory. Therefor we apply the DMA range
+ * offset ourselves.
+ */
+static dma_addr_t ethosu_buffer_dma_ranges(struct device *dev,
+					   dma_addr_t dma_addr)
+{
+	struct device_node *node = dev->of_node;
+	const __be32 *ranges;
+	int len;
+	int naddr;
+	int nsize;
+	int inc;
+	int i;
+
+	if (!node)
+		return dma_addr;
+
+	/* Get the #address-cells and #size-cells properties */
+	naddr = of_n_addr_cells(node);
+	nsize = of_n_size_cells(node);
+
+	/* Read the 'dma-ranges' property */
+	ranges = of_get_property(node, "dma-ranges", &len);
+	if (!ranges || len <= 0)
+		return dma_addr;
+
+	dev_dbg(dev, "ranges=%p, len=%d, naddr=%d, nsize=%d\n",
+		ranges, len, naddr, nsize);
+
+	len /= sizeof(*ranges);
+	inc = naddr + naddr + nsize;
+
+	for (i = 0; (i + inc) <= len; i += inc) {
+		dma_addr_t daddr;
+		dma_addr_t paddr;
+		dma_addr_t size;
+
+		daddr = of_read_number(&ranges[i], naddr);
+		paddr = of_read_number(&ranges[i + naddr], naddr);
+		size = of_read_number(&ranges[i + naddr + naddr], nsize);
+
+		dev_dbg(dev, "daddr=0x%llx, paddr=0x%llx, size=0x%llx\n",
+			daddr, paddr, size);
+
+		if (dma_addr >= paddr && dma_addr < (paddr + size))
+			return dma_addr + daddr - paddr;
+	}
+
+	return dma_addr;
+}
+
+static bool ethosu_buffer_verify(struct file *file)
+{
+	return file->f_op == &ethosu_buffer_fops;
+}
+
+static void ethosu_buffer_destroy(struct kref *kref)
+{
+	struct ethosu_buffer *buf =
+		container_of(kref, struct ethosu_buffer, kref);
+
+	dev_info(buf->edev->dev, "Buffer destroy. handle=0x%pK\n", buf);
+
+	dma_free_coherent(buf->edev->dev, buf->capacity, buf->cpu_addr,
+			  buf->dma_addr_orig);
+	devm_kfree(buf->edev->dev, buf);
+}
+
+static int ethosu_buffer_release(struct inode *inode,
+				 struct file *file)
+{
+	struct ethosu_buffer *buf = file->private_data;
+
+	dev_info(buf->edev->dev, "Buffer release. handle=0x%pK\n", buf);
+
+	ethosu_buffer_put(buf);
+
+	return 0;
+}
+
+static int ethosu_buffer_mmap(struct file *file,
+			      struct vm_area_struct *vma)
+{
+	struct ethosu_buffer *buf = file->private_data;
+	int ret;
+
+	dev_info(buf->edev->dev, "Buffer mmap. handle=0x%pK\n", buf);
+
+	ret = dma_mmap_coherent(buf->edev->dev, vma, buf->cpu_addr,
+				buf->dma_addr_orig,
+				buf->capacity);
+
+	return ret;
+}
+
+static long ethosu_buffer_ioctl(struct file *file,
+				unsigned int cmd,
+				unsigned long arg)
+{
+	struct ethosu_buffer *buf = file->private_data;
+	void __user *udata = (void __user *)arg;
+	int ret = -EINVAL;
+
+	ret = mutex_lock_interruptible(&buf->edev->mutex);
+	if (ret)
+		return ret;
+
+	dev_info(buf->edev->dev, "Ioctl. cmd=%u, arg=%lu\n", cmd, arg);
+
+	switch (cmd) {
+	case ETHOSU_IOCTL_BUFFER_SET: {
+		struct ethosu_uapi_buffer uapi;
+
+		if (copy_from_user(&uapi, udata, sizeof(uapi)))
+			break;
+
+		dev_info(buf->edev->dev,
+			 "Ioctl: Buffer set. size=%u, offset=%u\n",
+			 uapi.size, uapi.offset);
+
+		ret = ethosu_buffer_resize(buf, uapi.size, uapi.offset);
+		break;
+	}
+	case ETHOSU_IOCTL_BUFFER_GET: {
+		struct ethosu_uapi_buffer uapi;
+
+		uapi.size = buf->size;
+		uapi.offset = buf->offset;
+
+		dev_info(buf->edev->dev,
+			 "Ioctl: Buffer get. size=%u, offset=%u\n",
+			 uapi.size, uapi.offset);
+
+		if (copy_to_user(udata, &uapi, sizeof(uapi)))
+			break;
+
+		ret = 0;
+		break;
+	}
+	default: {
+		dev_err(buf->edev->dev, "Invalid ioctl. cmd=%u, arg=%lu",
+			cmd, arg);
+		break;
+	}
+	}
+
+	mutex_unlock(&buf->edev->mutex);
+
+	return ret;
+}
+
+int ethosu_buffer_create(struct ethosu_device *edev,
+			 size_t capacity)
+{
+	struct ethosu_buffer *buf;
+	int ret = -ENOMEM;
+
+	buf = devm_kzalloc(edev->dev, sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	buf->edev = edev;
+	buf->capacity = capacity;
+	buf->offset = 0;
+	buf->size = 0;
+	kref_init(&buf->kref);
+
+	buf->cpu_addr = dma_alloc_coherent(buf->edev->dev, capacity,
+					   &buf->dma_addr_orig, GFP_KERNEL);
+	if (!buf->cpu_addr)
+		goto free_buf;
+
+	buf->dma_addr = ethosu_buffer_dma_ranges(buf->edev->dev,
+						 buf->dma_addr_orig);
+
+	ret = anon_inode_getfd("ethosu-buffer", &ethosu_buffer_fops, buf,
+			       O_RDWR | O_CLOEXEC);
+	if (ret < 0)
+		goto free_dma;
+
+	buf->file = fget(ret);
+	fput(buf->file);
+
+	dev_info(buf->edev->dev,
+		 "Buffer create. handle=0x%pK, capacity=%zu, cpu_addr=0x%pK, dma_addr=0x%llx, dma_addr_orig=0x%llx, phys_addr=0x%llx\n",
+		 buf, capacity, buf->cpu_addr, buf->dma_addr,
+		 buf->dma_addr_orig, virt_to_phys(buf->cpu_addr));
+
+	return ret;
+
+free_dma:
+	dma_free_coherent(buf->edev->dev, buf->capacity, buf->cpu_addr,
+			  buf->dma_addr_orig);
+
+free_buf:
+	devm_kfree(buf->edev->dev, buf);
+
+	return ret;
+}
+
+struct ethosu_buffer *ethosu_buffer_get_from_fd(int fd)
+{
+	struct ethosu_buffer *buf;
+	struct file *file;
+
+	file = fget(fd);
+	if (!file)
+		return ERR_PTR(-EINVAL);
+
+	if (!ethosu_buffer_verify(file)) {
+		fput(file);
+
+		return ERR_PTR(-EINVAL);
+	}
+
+	buf = file->private_data;
+	ethosu_buffer_get(buf);
+	fput(file);
+
+	return buf;
+}
+
+void ethosu_buffer_get(struct ethosu_buffer *buf)
+{
+	kref_get(&buf->kref);
+}
+
+void ethosu_buffer_put(struct ethosu_buffer *buf)
+{
+	kref_put(&buf->kref, ethosu_buffer_destroy);
+}
+
+int ethosu_buffer_resize(struct ethosu_buffer *buf,
+			 size_t size,
+			 size_t offset)
+{
+	if ((size + offset) > buf->capacity)
+		return -EINVAL;
+
+	buf->size = size;
+	buf->offset = offset;
+
+	return 0;
+}