[PATCH RFC v4 2/2] dmaengine: avalon-test: Intel Avalon-MM DMA Interface for PCIe test
From: Alexander Gordeev
Date: Wed Oct 30 2019 - 09:32:23 EST
This is a sample implementation of a driver using "avalon-dma" to
perform data transfers between target device memory and system memory:
+----------+ +----------+ +----------+
| RAM |<-->| Avalon |<---PCIe--->| Host |
+----------+ +----------+ +----------+
The target device is expected to use only Avalon-MM DMA Interface for
PCIe to initiate DMA transactions - without custom hardware specifics
to make such transfers possible.
Unlike "dmatest" driver, the contents of DMAed data is not manipulated by
"avalon-test" in any way. It is basically pass-through and the the data
are fully dependent on the target device implementation. Thus, it is up
to the users to analyze received or provide meaningful transmitted data.
CC: dmaengine@xxxxxxxxxxxxxxx
Signed-off-by: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
---
drivers/dma/Kconfig | 1 +
drivers/dma/Makefile | 1 +
drivers/dma/avalon-test/Kconfig | 12 +
drivers/dma/avalon-test/Makefile | 14 +
drivers/dma/avalon-test/avalon-dev.c | 108 +++++
drivers/dma/avalon-test/avalon-dev.h | 33 ++
drivers/dma/avalon-test/avalon-ioctl.c | 100 +++++
drivers/dma/avalon-test/avalon-ioctl.h | 13 +
drivers/dma/avalon-test/avalon-mmap.c | 75 ++++
drivers/dma/avalon-test/avalon-mmap.h | 13 +
drivers/dma/avalon-test/avalon-sg-buf.c | 131 ++++++
drivers/dma/avalon-test/avalon-sg-buf.h | 27 ++
drivers/dma/avalon-test/avalon-xfer.c | 559 ++++++++++++++++++++++++
drivers/dma/avalon-test/avalon-xfer.h | 29 ++
include/uapi/linux/avalon-ioctl.h | 32 ++
15 files changed, 1148 insertions(+)
create mode 100644 drivers/dma/avalon-test/Kconfig
create mode 100644 drivers/dma/avalon-test/Makefile
create mode 100644 drivers/dma/avalon-test/avalon-dev.c
create mode 100644 drivers/dma/avalon-test/avalon-dev.h
create mode 100644 drivers/dma/avalon-test/avalon-ioctl.c
create mode 100644 drivers/dma/avalon-test/avalon-ioctl.h
create mode 100644 drivers/dma/avalon-test/avalon-mmap.c
create mode 100644 drivers/dma/avalon-test/avalon-mmap.h
create mode 100644 drivers/dma/avalon-test/avalon-sg-buf.c
create mode 100644 drivers/dma/avalon-test/avalon-sg-buf.h
create mode 100644 drivers/dma/avalon-test/avalon-xfer.c
create mode 100644 drivers/dma/avalon-test/avalon-xfer.h
create mode 100644 include/uapi/linux/avalon-ioctl.h
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index f6f43480a4a4..4b3c6a6baf4c 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -670,6 +670,7 @@ source "drivers/dma/sh/Kconfig"
source "drivers/dma/ti/Kconfig"
source "drivers/dma/avalon/Kconfig"
+source "drivers/dma/avalon-test/Kconfig"
# clients
comment "DMA Clients"
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index fd7e11417b73..eb3ee7f6cac6 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -76,6 +76,7 @@ obj-$(CONFIG_XGENE_DMA) += xgene-dma.o
obj-$(CONFIG_ZX_DMA) += zx_dma.o
obj-$(CONFIG_ST_FDMA) += st_fdma.o
obj-$(CONFIG_AVALON_DMA) += avalon/
+obj-$(CONFIG_AVALON_TEST) += avalon-test/
obj-y += mediatek/
obj-y += qcom/
diff --git a/drivers/dma/avalon-test/Kconfig b/drivers/dma/avalon-test/Kconfig
new file mode 100644
index 000000000000..b4d22720ce23
--- /dev/null
+++ b/drivers/dma/avalon-test/Kconfig
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2019, The Linux Foundation. All rights reserved.
+# Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+#
+# Avalon DMA engine
+#
+config AVALON_TEST
+ select AVALON_DMA
+ tristate "Intel Avalon-MM DMA Interface for PCIe test driver"
+ help
+ This selects a test driver for Avalon-MM DMA Interface for PCI
diff --git a/drivers/dma/avalon-test/Makefile b/drivers/dma/avalon-test/Makefile
new file mode 100644
index 000000000000..2387fc41c3ad
--- /dev/null
+++ b/drivers/dma/avalon-test/Makefile
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2019, The Linux Foundation. All rights reserved.
+# Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+#
+# Avalon DMA driver
+#
+obj-$(CONFIG_AVALON_TEST) += avalon-test.o
+
+avalon-test-objs := avalon-dev.o \
+ avalon-ioctl.o \
+ avalon-mmap.o \
+ avalon-sg-buf.o \
+ avalon-xfer.o
diff --git a/drivers/dma/avalon-test/avalon-dev.c b/drivers/dma/avalon-test/avalon-dev.c
new file mode 100644
index 000000000000..34d950789379
--- /dev/null
+++ b/drivers/dma/avalon-test/avalon-dev.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ * Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+ *
+ * Avalon DMA driver
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/pci.h>
+
+#include "avalon-dev.h"
+#include "avalon-ioctl.h"
+#include "avalon-mmap.h"
+
+unsigned int mem_base = 0x70000000;
+module_param(mem_base, uint, 0644);
+MODULE_PARM_DESC(mem_base, "Device memory base (default: 0x70000000)");
+
+unsigned int mem_size = 0x10000000;
+module_param(mem_size, uint, 0644);
+MODULE_PARM_DESC(mem_size, "Device memory size (default: 0x10000000)");
+
+unsigned int dma_size = 0x200000;
+module_param(dma_size, uint, 0644);
+MODULE_PARM_DESC(dma_size, "DMA buffer transfer size (default: 0x200000)");
+
+unsigned int dma_size_sg = 0x10000000;
+module_param(dma_size_sg, uint, 0644);
+MODULE_PARM_DESC(dma_size_sg,
+ "DMA scatter list transfer size (default: 0x10000000)");
+
+unsigned int nr_dma_reps = 4;
+module_param(nr_dma_reps, uint, 0644);
+MODULE_PARM_DESC(nr_dma_reps, "Device memory size (default: 4)");
+
+unsigned int dmas_per_cpu = 8;
+module_param(dmas_per_cpu, uint, 0644);
+MODULE_PARM_DESC(dmas_per_cpu, "Device memory size (default: 8)");
+
+const struct file_operations avalon_dev_fops = {
+ .llseek = generic_file_llseek,
+ .unlocked_ioctl = avalon_dev_ioctl,
+ .mmap = avalon_dev_mmap,
+};
+
+static struct avalon_dev avalon_dev;
+
+static bool filter(struct dma_chan *chan, void *filter_param)
+{
+ return !strcmp(chan->device->dev->driver->name, "avalon-dma");
+}
+
+static int __init avalon_drv_init(void)
+{
+ struct avalon_dev *adev = &avalon_dev;
+ struct dma_chan *chan;
+ dma_cap_mask_t mask;
+ int ret;
+
+ if (!IS_ALIGNED(mem_base, PAGE_SIZE) ||
+ !IS_ALIGNED(mem_size, PAGE_SIZE) ||
+ !IS_ALIGNED(dma_size, sizeof(u32)) ||
+ !IS_ALIGNED(dma_size_sg, sizeof(u32)))
+ return -EINVAL;
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ chan = dma_request_channel(mask, filter, NULL);
+ if (!chan)
+ return -ENODEV;
+
+ adev->dma_chan = chan;
+
+ adev->misc_dev.minor = MISC_DYNAMIC_MINOR;
+ adev->misc_dev.name = DEVICE_NAME;
+ adev->misc_dev.nodename = DEVICE_NAME;
+ adev->misc_dev.fops = &avalon_dev_fops;
+ adev->misc_dev.mode = 0644;
+
+ ret = misc_register(&adev->misc_dev);
+ if (ret) {
+ dma_release_channel(chan);
+ return ret;
+ }
+
+ dma_size = min(dma_size_sg, mem_size);
+ dma_size_sg = min(dma_size_sg, mem_size);
+
+ return 0;
+}
+
+static void __exit avalon_drv_exit(void)
+{
+ struct avalon_dev *adev = &avalon_dev;
+
+ misc_deregister(&adev->misc_dev);
+ dma_release_channel(adev->dma_chan);
+}
+
+module_init(avalon_drv_init);
+module_exit(avalon_drv_exit);
+
+MODULE_AUTHOR("Alexander Gordeev <a.gordeev.box@xxxxxxxxx>");
+MODULE_DESCRIPTION("Avalon DMA control driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/dma/avalon-test/avalon-dev.h b/drivers/dma/avalon-test/avalon-dev.h
new file mode 100644
index 000000000000..ad8f2f5717fa
--- /dev/null
+++ b/drivers/dma/avalon-test/avalon-dev.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ * Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+ *
+ * Avalon DMA driver
+ */
+#ifndef __AVALON_DEV_H__
+#define __AVALON_DEV_H__
+
+#include <linux/dmaengine.h>
+#include <linux/miscdevice.h>
+
+#define DEVICE_NAME "avalon-dev"
+
+extern unsigned int mem_base;
+extern unsigned int mem_size;
+extern unsigned int dma_size;
+extern unsigned int dma_size_sg;
+extern unsigned int nr_dma_reps;
+extern unsigned int dmas_per_cpu;
+
+struct avalon_dev {
+ struct dma_chan *dma_chan;
+ struct miscdevice misc_dev;
+};
+
+static inline struct device *chan_to_dev(struct dma_chan *chan)
+{
+ return chan->device->dev;
+}
+
+#endif
diff --git a/drivers/dma/avalon-test/avalon-ioctl.c b/drivers/dma/avalon-test/avalon-ioctl.c
new file mode 100644
index 000000000000..8bbea70a58be
--- /dev/null
+++ b/drivers/dma/avalon-test/avalon-ioctl.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ * Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+ *
+ * Avalon DMA driver
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/uio.h>
+
+#include <uapi/linux/avalon-ioctl.h>
+
+#include "avalon-xfer.h"
+
+long avalon_dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct avalon_dev *adev = container_of(file->private_data,
+ struct avalon_dev, misc_dev);
+ struct dma_chan *chan = adev->dma_chan;
+ struct iovec iovec[2];
+ void __user *buf = NULL, __user *buf_rd = NULL, __user *buf_wr = NULL;
+ size_t len = 0, len_rd = 0, len_wr = 0;
+ int ret = -EINVAL;
+
+ switch (cmd) {
+ case IOCTL_AVALON_DMA_GET_INFO: {
+ struct avalon_dma_info info = {
+ .mem_addr = mem_base,
+ .mem_size = mem_size,
+ .dma_size = dma_size,
+ .dma_size_sg = dma_size_sg,
+ };
+
+ if (copy_to_user((void *)arg, &info, sizeof(info)))
+ return -EFAULT;
+
+ return 0;
+ }
+ case IOCTL_AVALON_DMA_SET_INFO:
+ return -EINVAL;
+ case IOCTL_AVALON_DMA_READ:
+ case IOCTL_AVALON_DMA_WRITE:
+ case IOCTL_AVALON_DMA_READ_SG:
+ case IOCTL_AVALON_DMA_WRITE_SG:
+ case IOCTL_AVALON_DMA_READ_SG_SMP:
+ case IOCTL_AVALON_DMA_WRITE_SG_SMP:
+ if (copy_from_user(iovec, (void *)arg, sizeof(iovec[0])))
+ return -EFAULT;
+
+ buf = iovec[0].iov_base;
+ len = iovec[0].iov_len;
+
+ break;
+ case IOCTL_AVALON_DMA_RDWR:
+ case IOCTL_AVALON_DMA_RDWR_SG:
+ if (copy_from_user(iovec, (void *)arg, sizeof(iovec)))
+ return -EFAULT;
+
+ buf_rd = iovec[0].iov_base;
+ len_rd = iovec[0].iov_len;
+
+ buf_wr = iovec[1].iov_base;
+ len_wr = iovec[1].iov_len;
+
+ break;
+ default:
+ return -EINVAL;
+ };
+
+ switch (cmd) {
+ case IOCTL_AVALON_DMA_READ:
+ ret = xfer_single(chan, DMA_FROM_DEVICE, buf, len);
+ break;
+ case IOCTL_AVALON_DMA_WRITE:
+ ret = xfer_single(chan, DMA_TO_DEVICE, buf, len);
+ break;
+ case IOCTL_AVALON_DMA_RDWR:
+ ret = xfer_rw_single(chan, buf_rd, len_rd, buf_wr, len_wr);
+ break;
+ case IOCTL_AVALON_DMA_READ_SG:
+ ret = xfer_sg(chan, DMA_FROM_DEVICE, buf, len, false);
+ break;
+ case IOCTL_AVALON_DMA_WRITE_SG:
+ ret = xfer_sg(chan, DMA_TO_DEVICE, buf, len, false);
+ break;
+ case IOCTL_AVALON_DMA_READ_SG_SMP:
+ ret = xfer_sg(chan, DMA_FROM_DEVICE, buf, len, true);
+ break;
+ case IOCTL_AVALON_DMA_WRITE_SG_SMP:
+ ret = xfer_sg(chan, DMA_TO_DEVICE, buf, len, true);
+ break;
+ case IOCTL_AVALON_DMA_RDWR_SG:
+ ret = xfer_rw_sg(chan, buf_rd, len_rd, buf_wr, len_wr);
+ break;
+ };
+
+ return ret;
+}
diff --git a/drivers/dma/avalon-test/avalon-ioctl.h b/drivers/dma/avalon-test/avalon-ioctl.h
new file mode 100644
index 000000000000..a10ab0b5d67c
--- /dev/null
+++ b/drivers/dma/avalon-test/avalon-ioctl.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ * Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+ *
+ * Avalon DMA driver
+ */
+#ifndef __AVALON_IOCTL_H__
+#define __AVALON_IOCTL_H__
+
+long avalon_dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+
+#endif
diff --git a/drivers/dma/avalon-test/avalon-mmap.c b/drivers/dma/avalon-test/avalon-mmap.c
new file mode 100644
index 000000000000..f7c02e0d2ea1
--- /dev/null
+++ b/drivers/dma/avalon-test/avalon-mmap.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ * Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+ *
+ * Avalon DMA driver
+ */
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/dma-direction.h>
+
+#include "avalon-dev.h"
+#include "avalon-sg-buf.h"
+
+const gfp_t gfp_flags = GFP_KERNEL;
+
+static void avalon_drv_vm_close(struct vm_area_struct *vma)
+{
+ struct dma_sg_buf *sg_buf = vma->vm_private_data;
+
+ dma_sg_buf_free(sg_buf);
+}
+
+static const struct vm_operations_struct avalon_drv_vm_ops = {
+ .close = avalon_drv_vm_close,
+};
+
+int avalon_dev_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct avalon_dev *adev = container_of(file->private_data,
+ struct avalon_dev, misc_dev);
+ struct device *dev = chan_to_dev(adev->dma_chan);
+ unsigned long addr = vma->vm_start;
+ unsigned long size = vma->vm_end - vma->vm_start;
+ enum dma_data_direction dir;
+ struct dma_sg_buf *sg_buf;
+ int ret;
+ int i;
+
+ if (!IS_ALIGNED(addr, PAGE_SIZE) || !IS_ALIGNED(size, PAGE_SIZE))
+ return -EINVAL;
+ if ((vma->vm_pgoff * PAGE_SIZE + size) > mem_size)
+ return -EINVAL;
+ if (!(((vma->vm_flags & (VM_READ | VM_WRITE)) == VM_READ) ||
+ ((vma->vm_flags & (VM_READ | VM_WRITE)) == VM_WRITE)))
+ return -EINVAL;
+ if (!(vma->vm_flags & VM_SHARED))
+ return -EINVAL;
+
+ vma->vm_ops = &avalon_drv_vm_ops;
+
+ if (vma->vm_flags & VM_WRITE)
+ dir = DMA_TO_DEVICE;
+ else
+ dir = DMA_FROM_DEVICE;
+
+ sg_buf = dma_sg_buf_alloc(dev, size, dir, gfp_flags);
+ if (IS_ERR(sg_buf))
+ return PTR_ERR(sg_buf);
+
+ for (i = 0; size > 0; i++) {
+ ret = vm_insert_page(vma, addr, sg_buf->pages[i]);
+ if (ret) {
+ dma_sg_buf_free(sg_buf);
+ return ret;
+ }
+
+ addr += PAGE_SIZE;
+ size -= PAGE_SIZE;
+ };
+
+ vma->vm_private_data = sg_buf;
+
+ return 0;
+}
diff --git a/drivers/dma/avalon-test/avalon-mmap.h b/drivers/dma/avalon-test/avalon-mmap.h
new file mode 100644
index 000000000000..3d3878f236cf
--- /dev/null
+++ b/drivers/dma/avalon-test/avalon-mmap.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ * Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+ *
+ * Avalon DMA driver
+ */
+#ifndef __AVALON_MMAP_H__
+#define __AVALON_MMAP_H__
+
+int avalon_dev_mmap(struct file *file, struct vm_area_struct *vma);
+
+#endif
diff --git a/drivers/dma/avalon-test/avalon-sg-buf.c b/drivers/dma/avalon-test/avalon-sg-buf.c
new file mode 100644
index 000000000000..ac1bb85d2e64
--- /dev/null
+++ b/drivers/dma/avalon-test/avalon-sg-buf.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ * Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+ *
+ * Avalon DMA driver
+ */
+#include <linux/kernel.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+
+#include "avalon-sg-buf.h"
+
+static int dma_sg_alloc_compacted(struct dma_sg_buf *buf, gfp_t gfp_flags)
+{
+ unsigned int last_page = 0;
+ int size = buf->size;
+
+ while (size > 0) {
+ struct page *pages;
+ int order;
+ int i;
+
+ order = get_order(size);
+ if ((PAGE_SIZE << order) > size)
+ order--;
+
+ pages = NULL;
+ while (!pages) {
+ pages = alloc_pages(gfp_flags | __GFP_NOWARN, order);
+ if (pages)
+ break;
+
+ if (order == 0) {
+ while (last_page--)
+ __free_page(buf->pages[last_page]);
+ return -ENOMEM;
+ }
+ order--;
+ }
+
+ split_page(pages, order);
+ for (i = 0; i < (1 << order); i++)
+ buf->pages[last_page++] = &pages[i];
+
+ size -= PAGE_SIZE << order;
+ }
+
+ return 0;
+}
+
+struct dma_sg_buf *dma_sg_buf_alloc(struct device *dev,
+ unsigned long size,
+ enum dma_data_direction dma_dir,
+ gfp_t gfp_flags)
+{
+ struct dma_sg_buf *buf;
+ struct sg_table *sgt;
+ int ret;
+ int num_pages;
+
+ buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ buf->dma_dir = dma_dir;
+ buf->size = size;
+ buf->num_pages = size >> PAGE_SHIFT;
+
+ buf->pages = kvcalloc(buf->num_pages, sizeof(struct page *), GFP_KERNEL);
+ if (!buf->pages)
+ goto free_buf;
+
+ ret = dma_sg_alloc_compacted(buf, gfp_flags);
+ if (ret)
+ goto free_arr;
+
+ ret = sg_alloc_table_from_pages(&buf->sgt, buf->pages,
+ buf->num_pages, 0, size,
+ GFP_KERNEL);
+ if (ret)
+ goto free_pages;
+
+ buf->dev = get_device(dev);
+
+ sgt = &buf->sgt;
+
+ sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
+ buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+ if (!sgt->nents)
+ goto free_sgt;
+
+ buf->vaddr = vm_map_ram(buf->pages, buf->num_pages, -1, PAGE_KERNEL);
+ if (!buf->vaddr)
+ goto unmap_sg;
+
+ return buf;
+
+unmap_sg:
+ dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
+ buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+free_sgt:
+ put_device(buf->dev);
+ sg_free_table(&buf->sgt);
+free_pages:
+ num_pages = buf->num_pages;
+ while (num_pages--)
+ __free_page(buf->pages[num_pages]);
+free_arr:
+ kvfree(buf->pages);
+free_buf:
+ kfree(buf);
+
+ return ERR_PTR(-ENOMEM);
+}
+
+void dma_sg_buf_free(struct dma_sg_buf *buf)
+{
+ struct sg_table *sgt = &buf->sgt;
+ int i = buf->num_pages;
+
+ dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
+ buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+ vm_unmap_ram(buf->vaddr, buf->num_pages);
+ sg_free_table(&buf->sgt);
+ while (--i >= 0)
+ __free_page(buf->pages[i]);
+ kvfree(buf->pages);
+ put_device(buf->dev);
+ kfree(buf);
+}
diff --git a/drivers/dma/avalon-test/avalon-sg-buf.h b/drivers/dma/avalon-test/avalon-sg-buf.h
new file mode 100644
index 000000000000..a5cce1c18714
--- /dev/null
+++ b/drivers/dma/avalon-test/avalon-sg-buf.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ *
+ * Avalon DMA driver
+ */
+#ifndef __AVALON_SG_BUF_H__
+#define __AVALON_SG_BUF_H__
+
+struct dma_sg_buf {
+ struct device *dev;
+ void *vaddr;
+ struct page **pages;
+ enum dma_data_direction dma_dir;
+ struct sg_table sgt;
+ size_t size;
+ unsigned int num_pages;
+};
+
+struct dma_sg_buf *dma_sg_buf_alloc(struct device *dev,
+ unsigned long size,
+ enum dma_data_direction dma_dir,
+ gfp_t gfp_flags);
+void dma_sg_buf_free(struct dma_sg_buf *buf);
+
+#endif
diff --git a/drivers/dma/avalon-test/avalon-xfer.c b/drivers/dma/avalon-test/avalon-xfer.c
new file mode 100644
index 000000000000..ab24e15b1bf1
--- /dev/null
+++ b/drivers/dma/avalon-test/avalon-xfer.c
@@ -0,0 +1,559 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ * Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+ *
+ * Avalon DMA driver
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+#include <linux/uaccess.h>
+#include <linux/kthread.h>
+#include <linux/sched/signal.h>
+#include <linux/dmaengine.h>
+
+#include "avalon-xfer.h"
+#include "avalon-sg-buf.h"
+
+struct callback_info {
+ struct completion completion;
+ atomic_t counter;
+};
+
+static void init_callback_info(struct callback_info *info, int value)
+{
+ init_completion(&info->completion);
+
+ /*
+ * Pairs with smp_rmb() in xfer_callback()
+ */
+ atomic_set(&info->counter, value);
+ smp_wmb();
+}
+
+static void xfer_callback(void *arg)
+{
+ struct callback_info *info = arg;
+
+ /*
+ * Pairs with smp_wmb() in init_callback_info()
+ */
+ smp_rmb();
+ if (atomic_dec_and_test(&info->counter))
+ complete(&info->completion);
+}
+
+static int config_chan(struct dma_chan *chan,
+ enum dma_data_direction dir,
+ dma_addr_t dev_addr)
+{
+ struct dma_slave_config config = {
+ .direction = dir,
+ .src_addr = dev_addr,
+ .dst_addr = dev_addr,
+ };
+
+ return dmaengine_slave_config(chan, &config);
+}
+
+static int submit_tx(struct dma_chan *chan,
+ struct dma_async_tx_descriptor *tx,
+ dma_async_tx_callback callback, void *callback_param)
+{
+ dma_cookie_t cookie;
+
+ tx->callback = callback;
+ tx->callback_param = callback_param;
+
+ cookie = dmaengine_submit(tx);
+ if (cookie < 0) {
+ dmaengine_terminate_sync(chan);
+ return cookie;
+ }
+
+ return 0;
+}
+
+static
+int submit_xfer_single(struct dma_chan *chan,
+ enum dma_data_direction dir,
+ dma_addr_t dev_addr,
+ dma_addr_t host_addr, unsigned int size,
+ dma_async_tx_callback callback, void *callback_param)
+{
+ struct dma_async_tx_descriptor *tx;
+ int ret;
+
+ ret = config_chan(chan, dir, dev_addr);
+ if (ret)
+ return ret;
+
+ tx = dmaengine_prep_slave_single(chan, host_addr, size, dir, 0);
+ if (!tx)
+ return -ENOMEM;
+
+ ret = submit_tx(chan, tx, callback, callback_param);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static
+int submit_xfer_sg(struct dma_chan *chan,
+ enum dma_data_direction dir,
+ dma_addr_t dev_addr,
+ struct scatterlist *sg, unsigned int sg_len,
+ dma_async_tx_callback callback, void *callback_param)
+{
+ struct dma_async_tx_descriptor *tx;
+ int ret;
+
+ ret = config_chan(chan, dir, dev_addr);
+ if (ret)
+ return ret;
+
+ tx = dmaengine_prep_slave_sg(chan, sg, sg_len, dir, 0);
+ if (!tx)
+ return -ENOMEM;
+
+ ret = submit_tx(chan, tx, callback, callback_param);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+int xfer_single(struct dma_chan *chan,
+ enum dma_data_direction dir,
+ void __user *user_buf, size_t user_len)
+{
+ struct device *dev = chan_to_dev(chan);
+ dma_addr_t dma_addr;
+ void *buf;
+ struct callback_info info;
+ int ret;
+ int i;
+
+ if (user_len < dma_size)
+ return -EINVAL;
+ if ((dir != DMA_TO_DEVICE) && (dir != DMA_FROM_DEVICE))
+ return -EINVAL;
+
+ user_len = min_t(size_t, user_len, dma_size);
+
+ buf = kzalloc(dma_size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ if (dir == DMA_TO_DEVICE) {
+ if (copy_from_user(buf, user_buf, user_len)) {
+ ret = -EFAULT;
+ goto free_buf;
+ }
+ }
+
+ dma_addr = dma_map_single(dev, buf, dma_size, dir);
+ if (dma_mapping_error(dev, dma_addr)) {
+ ret = -ENOMEM;
+ goto free_buf;
+ }
+
+ init_callback_info(&info, nr_dma_reps);
+
+ for (i = 0; i < nr_dma_reps; i++) {
+ ret = submit_xfer_single(chan, dir,
+ mem_base, dma_addr, dma_size,
+ xfer_callback, &info);
+ if (ret)
+ goto unmap_buf;
+ }
+
+ dma_async_issue_pending(chan);
+
+ ret = wait_for_completion_interruptible(&info.completion);
+ if (ret)
+ goto unmap_buf;
+
+ if (dir == DMA_FROM_DEVICE) {
+ if (copy_to_user(user_buf, buf, user_len))
+ ret = -EFAULT;
+ }
+
+unmap_buf:
+ dma_unmap_single(dev, dma_addr, dma_size, dir);
+
+free_buf:
+ kfree(buf);
+
+ return ret;
+}
+
+int xfer_rw_single(struct dma_chan *chan,
+ void __user *user_buf_rd, size_t user_len_rd,
+ void __user *user_buf_wr, size_t user_len_wr)
+{
+ struct device *dev = chan_to_dev(chan);
+ dma_addr_t target_rd = mem_base;
+ dma_addr_t target_wr = target_rd + dma_size;
+ dma_addr_t dma_addr_rd, dma_addr_wr;
+ void *buf_rd, *buf_wr;
+ struct callback_info info;
+ int ret;
+ int i;
+
+ if ((user_len_rd < dma_size) || (user_len_wr < dma_size))
+ return -EINVAL;
+
+ user_len_rd = min_t(size_t, user_len_rd, dma_size);
+ user_len_wr = min_t(size_t, user_len_wr, dma_size);
+
+ buf_rd = kzalloc(dma_size, GFP_KERNEL);
+ if (!buf_rd) {
+ ret = -ENOMEM;
+ goto alloc_err;
+ }
+
+ buf_wr = kzalloc(dma_size, GFP_KERNEL);
+ if (!buf_wr) {
+ ret = -ENOMEM;
+ goto free_buf_rd;
+ }
+
+ if (copy_from_user(buf_wr, user_buf_wr, user_len_wr)) {
+ ret = -EFAULT;
+ goto free_buf_wr;
+ }
+
+ dma_addr_rd = dma_map_single(dev, buf_rd, dma_size, DMA_FROM_DEVICE);
+ if (dma_mapping_error(dev, dma_addr_rd)) {
+ ret = -ENOMEM;
+ goto free_buf_wr;
+ }
+
+ dma_addr_wr = dma_map_single(dev, buf_wr, dma_size, DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, dma_addr_rd)) {
+ ret = -ENOMEM;
+ goto unmap_buf_rd;
+ }
+
+ init_callback_info(&info, 2 * nr_dma_reps);
+
+ for (i = 0; i < nr_dma_reps; i++) {
+ ret = submit_xfer_single(chan, DMA_TO_DEVICE,
+ target_wr, dma_addr_wr, dma_size,
+ xfer_callback, &info);
+ if (ret)
+ goto unmap_buf_wr;
+
+ ret = submit_xfer_single(chan, DMA_FROM_DEVICE,
+ target_rd, dma_addr_rd, dma_size,
+ xfer_callback, &info);
+ if (ret)
+ goto unmap_buf_wr;
+ }
+
+ dma_async_issue_pending(chan);
+
+ ret = wait_for_completion_interruptible(&info.completion);
+ if (ret)
+ goto unmap_buf_wr;
+
+ if (copy_to_user(user_buf_rd, buf_rd, user_len_rd))
+ ret = -EFAULT;
+
+unmap_buf_wr:
+ dma_unmap_single(dev, dma_addr_wr, dma_size, DMA_TO_DEVICE);
+
+unmap_buf_rd:
+ dma_unmap_single(dev, dma_addr_rd, dma_size, DMA_FROM_DEVICE);
+
+free_buf_wr:
+ kfree(buf_wr);
+
+free_buf_rd:
+ kfree(buf_rd);
+
+alloc_err:
+ return ret;
+}
+
+static int kthread_xfer_rw_sg(struct dma_chan *chan,
+ enum dma_data_direction dir,
+ dma_addr_t dev_addr,
+ struct scatterlist *sg, unsigned int sg_len,
+ dma_async_tx_callback callback)
+{
+ struct callback_info info;
+ int ret;
+ int i;
+
+ while (!kthread_should_stop()) {
+ init_callback_info(&info, nr_dma_reps);
+
+ for (i = 0; i < nr_dma_reps; i++) {
+ ret = submit_xfer_sg(chan, dir,
+ dev_addr, sg, sg_len,
+ callback, &info);
+ if (ret)
+ return ret;
+ }
+
+ dma_async_issue_pending(chan);
+
+ ret = wait_for_completion_interruptible(&info.completion);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+struct kthread_xfer_rw_sg_data {
+ struct dma_chan *chan;
+ enum dma_data_direction direction;
+ dma_addr_t dev_addr;
+ struct scatterlist *sg;
+ unsigned int sg_len;
+ dma_async_tx_callback callback;
+};
+
+static int __kthread_xfer_rw_sg(void *__data)
+{
+ struct kthread_xfer_rw_sg_data *data = __data;
+
+ return kthread_xfer_rw_sg(data->chan, data->direction,
+ data->dev_addr, data->sg, data->sg_len,
+ data->callback);
+}
+
+static int __xfer_sg_smp(struct dma_chan *chan,
+ enum dma_data_direction dir,
+ dma_addr_t dev_addr,
+ struct scatterlist *sg, unsigned int sg_len,
+ dma_async_tx_callback callback)
+{
+ struct kthread_xfer_rw_sg_data data = {
+ chan, dir,
+ dev_addr, sg, sg_len,
+ callback
+ };
+ struct task_struct *task;
+ struct task_struct **tasks;
+ int nr_tasks = dmas_per_cpu * num_online_cpus();
+ int n, cpu;
+ int ret = 0;
+ int i = 0;
+
+ tasks = kmalloc_array(nr_tasks, sizeof(tasks[0]), GFP_KERNEL);
+ if (!tasks)
+ return -ENOMEM;
+
+ for (n = 0; n < dmas_per_cpu; n++) {
+ for_each_online_cpu(cpu) {
+ if (i >= nr_tasks) {
+ ret = -ENOMEM;
+ goto kthread_err;
+ }
+
+ task = kthread_create(__kthread_xfer_rw_sg,
+ &data, "avalon-dma-%d-%d",
+ cpu, n);
+ if (IS_ERR(task)) {
+ ret = PTR_ERR(task);
+ goto kthread_err;
+ }
+
+ kthread_bind(task, cpu);
+
+ tasks[i] = task;
+ i++;
+ }
+ }
+
+ for (n = 0; n < i; n++)
+ wake_up_process(tasks[n]);
+
+ /*
+ * Run child kthreads until user sent a signal (i.e Ctrl+C)
+ * and clear the signal to avid user program from being killed.
+ */
+ schedule_timeout_interruptible(MAX_SCHEDULE_TIMEOUT);
+ flush_signals(current);
+
+kthread_err:
+ while (--i >= 0)
+ kthread_stop(tasks[i]);
+
+ kfree(tasks);
+
+ return ret;
+}
+
+static int __xfer_sg(struct dma_chan *chan,
+ enum dma_data_direction dir,
+ dma_addr_t dev_addr,
+ struct scatterlist *sg, unsigned int sg_len,
+ dma_async_tx_callback callback)
+{
+ struct callback_info info;
+ int ret;
+ int i;
+
+ init_callback_info(&info, nr_dma_reps);
+
+ for (i = 0; i < nr_dma_reps; i++) {
+ ret = submit_xfer_sg(chan, dir, dev_addr, sg, sg_len,
+ callback, &info);
+ if (ret)
+ return ret;
+ }
+
+ dma_async_issue_pending(chan);
+
+ ret = wait_for_completion_interruptible(&info.completion);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static struct vm_area_struct *get_vma(unsigned long addr,
+ unsigned long size)
+{
+ struct vm_area_struct *vma;
+ unsigned long vm_size;
+
+ vma = find_vma(current->mm, addr);
+ if (!vma || (vma->vm_start != addr))
+ return ERR_PTR(-ENXIO);
+
+ vm_size = vma->vm_end - vma->vm_start;
+ if (size > vm_size)
+ return ERR_PTR(-EINVAL);
+
+ return vma;
+}
+
+int xfer_sg(struct dma_chan *chan,
+ enum dma_data_direction dir,
+ void __user *user_buf, size_t user_len,
+ bool is_smp)
+{
+ struct device *dev = chan_to_dev(chan);
+ int (*xfer)(struct dma_chan *chan,
+ enum dma_data_direction dir,
+ dma_addr_t dev_addr,
+ struct scatterlist *sg, unsigned int sg_len,
+ dma_async_tx_callback callback);
+ struct vm_area_struct *vma;
+ struct dma_sg_buf *sg_buf;
+ dma_addr_t dma_addr;
+ int ret;
+
+ vma = get_vma((unsigned long)user_buf, user_len);
+ if (IS_ERR(vma))
+ return PTR_ERR(vma);
+
+ sg_buf = vma->vm_private_data;
+ if (dir != sg_buf->dma_dir)
+ return -EINVAL;
+
+ if (is_smp)
+ xfer = __xfer_sg_smp;
+ else
+ xfer = __xfer_sg;
+
+ dma_addr = mem_base + vma->vm_pgoff * PAGE_SIZE;
+
+ dma_sync_sg_for_device(dev,
+ sg_buf->sgt.sgl, sg_buf->sgt.nents,
+ sg_buf->dma_dir);
+
+ ret = xfer(chan, dir,
+ dma_addr, sg_buf->sgt.sgl, sg_buf->sgt.nents,
+ xfer_callback);
+
+ dma_sync_sg_for_cpu(dev,
+ sg_buf->sgt.sgl, sg_buf->sgt.nents,
+ sg_buf->dma_dir);
+
+ return ret;
+}
+
+int xfer_rw_sg(struct dma_chan *chan,
+ void __user *user_buf_rd, size_t user_len_rd,
+ void __user *user_buf_wr, size_t user_len_wr)
+{
+ struct device *dev = chan_to_dev(chan);
+ dma_addr_t dma_addr_rd, dma_addr_wr;
+ struct callback_info info;
+ struct vm_area_struct *vma_rd, *vma_wr;
+ struct dma_sg_buf *sg_buf_rd, *sg_buf_wr;
+ int ret;
+ int i;
+
+ vma_rd = get_vma((unsigned long)user_buf_rd, user_len_rd);
+ if (IS_ERR(vma_rd))
+ return PTR_ERR(vma_rd);
+
+ vma_wr = get_vma((unsigned long)user_buf_wr, user_len_wr);
+ if (IS_ERR(vma_wr))
+ return PTR_ERR(vma_wr);
+
+ sg_buf_rd = vma_rd->vm_private_data;
+ sg_buf_wr = vma_wr->vm_private_data;
+
+ if ((sg_buf_rd->dma_dir != DMA_FROM_DEVICE) ||
+ (sg_buf_wr->dma_dir != DMA_TO_DEVICE))
+ return -EINVAL;
+
+ dma_addr_rd = mem_base + vma_rd->vm_pgoff * PAGE_SIZE;
+ dma_addr_wr = mem_base + vma_wr->vm_pgoff * PAGE_SIZE;
+
+ init_callback_info(&info, 2 * nr_dma_reps);
+
+ dma_sync_sg_for_device(dev,
+ sg_buf_rd->sgt.sgl,
+ sg_buf_rd->sgt.nents,
+ DMA_FROM_DEVICE);
+ dma_sync_sg_for_device(dev,
+ sg_buf_wr->sgt.sgl,
+ sg_buf_wr->sgt.nents,
+ DMA_TO_DEVICE);
+
+ for (i = 0; i < nr_dma_reps; i++) {
+ ret = submit_xfer_sg(chan, DMA_TO_DEVICE,
+ dma_addr_wr,
+ sg_buf_wr->sgt.sgl,
+ sg_buf_wr->sgt.nents,
+ xfer_callback, &info);
+ if (ret)
+ goto submit_err;
+
+ ret = submit_xfer_sg(chan, DMA_FROM_DEVICE,
+ dma_addr_rd,
+ sg_buf_rd->sgt.sgl,
+ sg_buf_rd->sgt.nents,
+ xfer_callback, &info);
+ if (ret)
+ goto submit_err;
+ }
+
+ dma_async_issue_pending(chan);
+
+ ret = wait_for_completion_interruptible(&info.completion);
+
+submit_err:
+ dma_sync_sg_for_cpu(dev,
+ sg_buf_rd->sgt.sgl,
+ sg_buf_rd->sgt.nents,
+ DMA_FROM_DEVICE);
+ dma_sync_sg_for_cpu(dev,
+ sg_buf_wr->sgt.sgl,
+ sg_buf_wr->sgt.nents,
+ DMA_TO_DEVICE);
+
+ return ret;
+}
diff --git a/drivers/dma/avalon-test/avalon-xfer.h b/drivers/dma/avalon-test/avalon-xfer.h
new file mode 100644
index 000000000000..3c1a096713d5
--- /dev/null
+++ b/drivers/dma/avalon-test/avalon-xfer.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ * Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+ *
+ * Avalon DMA driver
+ */
+#ifndef __AVALON_XFER_H__
+#define __AVALON_XFER_H__
+
+#include <linux/dma-direction.h>
+
+#include "avalon-dev.h"
+
+int xfer_single(struct dma_chan *chan,
+ enum dma_data_direction direction,
+ void __user *user_buf, size_t user_len);
+int xfer_rw_single(struct dma_chan *chan,
+ void __user *user_buf_rd, size_t user_len_rd,
+ void __user *user_buf_wr, size_t user_len_wr);
+int xfer_sg(struct dma_chan *chan,
+ enum dma_data_direction direction,
+ void __user *user_buf, size_t user_len,
+ bool is_smp);
+int xfer_rw_sg(struct dma_chan *chan,
+ void __user *user_buf_rd, size_t user_len_rd,
+ void __user *user_buf_wr, size_t user_len_wr);
+
+#endif
diff --git a/include/uapi/linux/avalon-ioctl.h b/include/uapi/linux/avalon-ioctl.h
new file mode 100644
index 000000000000..b929c2dd46ea
--- /dev/null
+++ b/include/uapi/linux/avalon-ioctl.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev.box@xxxxxxxxx>
+ */
+#ifndef _UAPI_LINUX_AVALON_IOCTL_H__
+#define _UAPI_LINUX_AVALON_IOCTL_H__
+
+#define AVALON_DEVICE_NAME "avalon-dev"
+
+struct avalon_dma_info {
+ size_t mem_addr;
+ size_t mem_size;
+ size_t dma_size;
+ size_t dma_size_sg;
+} __attribute((packed));
+
+#define AVALON_SIG 'V'
+
+#define IOCTL_AVALON_DMA_GET_INFO _IOR(AVALON_SIG, 0, struct avalon_dma_info)
+#define IOCTL_AVALON_DMA_SET_INFO _IOW(AVALON_SIG, 1, struct avalon_dma_info)
+#define IOCTL_AVALON_DMA_READ _IOR(AVALON_SIG, 2, struct iovec)
+#define IOCTL_AVALON_DMA_WRITE _IOW(AVALON_SIG, 3, struct iovec)
+#define IOCTL_AVALON_DMA_RDWR _IOWR(AVALON_SIG, 4, struct iovec[2])
+#define IOCTL_AVALON_DMA_READ_SG _IOR(AVALON_SIG, 5, struct iovec)
+#define IOCTL_AVALON_DMA_WRITE_SG _IOW(AVALON_SIG, 6, struct iovec)
+#define IOCTL_AVALON_DMA_RDWR_SG _IOWR(AVALON_SIG, 7, struct iovec[2])
+#define IOCTL_AVALON_DMA_READ_SG_SMP _IOR(AVALON_SIG, 8, struct iovec)
+#define IOCTL_AVALON_DMA_WRITE_SG_SMP _IOW(AVALON_SIG, 9, struct iovec)
+
+#endif
--
2.23.0