This is sample implementation of a driver that uses "avalon-dma"
driver interface to perform data transfers between on-chip and
system memory in devices using Avalon-MM DMA Interface for PCIe
design.
Companion user-level tool could be found at
g...@github.com:a-gordeev/avalon-drv-tool.git
CC: Michael Chen <micc...@altera.com>
CC: de...@driverdev.osuosl.org
CC: dmaeng...@vger.kernel.org
Signed-off-by: Alexander Gordeev <a.gordeev....@gmail.com>
---
drivers/staging/Kconfig | 2 +
drivers/staging/Makefile | 1 +
drivers/staging/avalon-drv/Kconfig | 34 +
drivers/staging/avalon-drv/Makefile | 14 +
drivers/staging/avalon-drv/avalon-drv-dev.c | 193 ++++++
drivers/staging/avalon-drv/avalon-drv-ioctl.c | 137 ++++
drivers/staging/avalon-drv/avalon-drv-ioctl.h | 12 +
drivers/staging/avalon-drv/avalon-drv-mmap.c | 93 +++
drivers/staging/avalon-drv/avalon-drv-mmap.h | 12 +
.../staging/avalon-drv/avalon-drv-sg-buf.c | 132 ++++
.../staging/avalon-drv/avalon-drv-sg-buf.h | 26 +
drivers/staging/avalon-drv/avalon-drv-util.c | 54 ++
drivers/staging/avalon-drv/avalon-drv-util.h | 12 +
drivers/staging/avalon-drv/avalon-drv-xfer.c | 655 ++++++++++++++++++
drivers/staging/avalon-drv/avalon-drv-xfer.h | 24 +
drivers/staging/avalon-drv/avalon-drv.h | 22 +
include/uapi/linux/avalon-drv-ioctl.h | 30 +
17 files changed, 1453 insertions(+)
create mode 100644 drivers/staging/avalon-drv/Kconfig
create mode 100644 drivers/staging/avalon-drv/Makefile
create mode 100644 drivers/staging/avalon-drv/avalon-drv-dev.c
create mode 100644 drivers/staging/avalon-drv/avalon-drv-ioctl.c
create mode 100644 drivers/staging/avalon-drv/avalon-drv-ioctl.h
create mode 100644 drivers/staging/avalon-drv/avalon-drv-mmap.c
create mode 100644 drivers/staging/avalon-drv/avalon-drv-mmap.h
create mode 100644 drivers/staging/avalon-drv/avalon-drv-sg-buf.c
create mode 100644 drivers/staging/avalon-drv/avalon-drv-sg-buf.h
create mode 100644 drivers/staging/avalon-drv/avalon-drv-util.c
create mode 100644 drivers/staging/avalon-drv/avalon-drv-util.h
create mode 100644 drivers/staging/avalon-drv/avalon-drv-xfer.c
create mode 100644 drivers/staging/avalon-drv/avalon-drv-xfer.h
create mode 100644 drivers/staging/avalon-drv/avalon-drv.h
create mode 100644 include/uapi/linux/avalon-drv-ioctl.h
diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index 31c732ececd1..6a4e9fdae9f6 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -122,4 +122,6 @@ source "drivers/staging/isdn/Kconfig"
source "drivers/staging/avalon-dma/Kconfig"
+source "drivers/staging/avalon-drv/Kconfig"
+
endif # STAGING
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index eb974cac85d3..e09e1aea1506 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -51,3 +51,4 @@ obj-$(CONFIG_FIELDBUS_DEV) += fieldbus/
obj-$(CONFIG_KPC2000) += kpc2000/
obj-$(CONFIG_ISDN_CAPI) += isdn/
obj-$(CONFIG_AVALON_DMA) += avalon-dma/
+obj-$(CONFIG_AVALON_DRV) += avalon-drv/
diff --git a/drivers/staging/avalon-drv/Kconfig
b/drivers/staging/avalon-drv/Kconfig
new file mode 100644
index 000000000000..18c43a65b6f5
--- /dev/null
+++ b/drivers/staging/avalon-drv/Kconfig
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Avalon DMA driver
+#
+# Author: Alexander Gordeev <a.gordeev....@gmail.com>
+#
+config AVALON_DRV
+ depends on AVALON_DMA
+ tristate "Avalon DMA driver"
+ help
+ This selects a driver for Avalon DMA
+
+config AVALON_DRV_PCI_VENDOR_ID
+ hex "PCI vendor ID"
+ default "0x1172"
+
+config AVALON_DRV_PCI_DEVICE_ID
+ hex "PCI device ID"
+ default "0xe003"
+
+config AVALON_DRV_PCI_BAR
+ int "PCI device BAR the Avalon DMA controller is mapped to"
+ range 0 5
+ default 0
+
+config AVALON_DRV_PCI_MSI_COUNT_ORDER
+ int "Count of MSIs the PCI device provides (order)"
+ range 0 5
+ default 5
+
+config AVALON_DRV_PCI_MSI_VECTOR
+ int "MSI vector the Avalon DMA controller uses in multi-MSI mode"
+ range 0 31
+ default 0
diff --git a/drivers/staging/avalon-drv/Makefile
b/drivers/staging/avalon-drv/Makefile
new file mode 100644
index 000000000000..2e0f5f46488e
--- /dev/null
+++ b/drivers/staging/avalon-drv/Makefile
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Avalon DMA driver
+#
+# Author: Alexander Gordeev <a.gordeev....@gmail.com>
+#
+obj-$(CONFIG_AVALON_DRV) += avalon-drv.o
+
+avalon-drv-objs := avalon-drv-dev.o \
+ avalon-drv-ioctl.o \
+ avalon-drv-mmap.o \
+ avalon-drv-sg-buf.o \
+ avalon-drv-xfer.o \
+ avalon-drv-util.o
diff --git a/drivers/staging/avalon-drv/avalon-drv-dev.c
b/drivers/staging/avalon-drv/avalon-drv-dev.c
new file mode 100644
index 000000000000..3c930770552f
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv-dev.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include "avalon-drv.h"
+#include "avalon-drv-ioctl.h"
+#include "avalon-drv-mmap.h"
+
+#define AVALON_DRV_PCI_VENDOR_ID CONFIG_AVALON_DRV_PCI_VENDOR_ID
+#define AVALON_DRV_PCI_DEVICE_ID CONFIG_AVALON_DRV_PCI_DEVICE_ID
+
+#define PCI_BAR CONFIG_AVALON_DRV_PCI_BAR
+#define PCI_MSI_VECTOR CONFIG_AVALON_DRV_PCI_MSI_VECTOR
+#define PCI_MSI_COUNT BIT(CONFIG_AVALON_DRV_PCI_MSI_COUNT_ORDER)
+
+const struct file_operations avalon_dev_fops = {
+ .llseek = generic_file_llseek,
+ .unlocked_ioctl = avalon_dev_ioctl,
+ .mmap = avalon_dev_mmap,
+};
+
+static int init_interrupts(struct pci_dev *pci_dev)
+{
+ int ret;
+
+ ret = pci_alloc_irq_vectors(pci_dev,
+ PCI_MSI_COUNT, PCI_MSI_COUNT,
+ PCI_IRQ_MSI);
+ if (ret < 0) {
+ goto msi_err;
+ } else if (ret != PCI_MSI_COUNT) {
+ ret = -ENOSPC;
+ goto nr_msi_err;
+ }
+
+ ret = pci_irq_vector(pci_dev, PCI_MSI_VECTOR);
+ if (ret < 0)
+ goto vec_err;
+
+ return ret;
+
+vec_err:
+nr_msi_err:
+ pci_disable_msi(pci_dev);
+
+msi_err:
+ return ret;
+}
+
+static void term_interrupts(struct pci_dev *pci_dev)
+{
+ pci_disable_msi(pci_dev);
+}
+
+static int avalon_dev_register(struct avalon_dev *avalon_dev,
+ const struct file_operations *fops)
+{
+ avalon_dev->misc_dev.minor = MISC_DYNAMIC_MINOR;
+ avalon_dev->misc_dev.name = DRIVER_NAME;
+ avalon_dev->misc_dev.nodename = DRIVER_NAME;
+ avalon_dev->misc_dev.fops = fops;
+ avalon_dev->misc_dev.mode = 0644;
+
+ return misc_register(&avalon_dev->misc_dev);
+}
+
+static void avalon_dev_unregister(struct avalon_dev *avalon_dev)
+{
+ misc_deregister(&avalon_dev->misc_dev);
+}
+
+static int __init avalon_pci_probe(struct pci_dev *pci_dev,
+ const struct pci_device_id *id)
+{
+ struct device *dev = &pci_dev->dev;
+ struct avalon_dev *avalon_dev;
+ void __iomem *regs;
+ int ret;
+
+ avalon_dev = kzalloc(sizeof(*avalon_dev), GFP_KERNEL);
+ if (!avalon_dev)
+ return -ENOMEM;
+
+ ret = pci_enable_device(pci_dev);
+ if (ret)
+ goto enable_err;
+
+ ret = pci_request_regions(pci_dev, DRIVER_NAME);
+ if (ret)
+ goto reg_err;
+
+ regs = pci_ioremap_bar(pci_dev, PCI_BAR);
+ if (!regs) {
+ ret = -ENOMEM;
+ goto ioremap_err;
+ }
+
+ ret = init_interrupts(pci_dev);
+ if (ret < 0)
+ goto int_err;
+
+ ret = avalon_dma_init(&avalon_dev->avalon_dma, dev, regs, ret);
+ if (ret)
+ goto dma_err;
+
+ ret = avalon_dev_register(avalon_dev, &avalon_dev_fops);
+ if (ret)
+ goto dev_reg_err;
+
+ pci_set_master(pci_dev);
+ pci_write_config_byte(pci_dev, PCI_INTERRUPT_LINE, pci_dev->irq);
+
+ avalon_dev->pci_dev = pci_dev;
+ pci_set_drvdata(pci_dev, avalon_dev);
+
+ return 0;
+
+ avalon_dev_unregister(avalon_dev);
+
+dev_reg_err:
+ avalon_dma_term(&avalon_dev->avalon_dma);
+
+dma_err:
+ term_interrupts(pci_dev);
+
+int_err:
+ pci_iounmap(pci_dev, regs);
+
+ioremap_err:
+ pci_release_regions(pci_dev);
+
+reg_err:
+ pci_disable_device(pci_dev);
+
+enable_err:
+ kfree(avalon_dev);
+
+ return ret;
+}
+
+static void __exit avalon_pci_remove(struct pci_dev *pci_dev)
+{
+ struct avalon_dev *avalon_dev = pci_get_drvdata(pci_dev);
+
+ pci_set_drvdata(pci_dev, NULL);
+
+ avalon_dev_unregister(avalon_dev);
+
+ avalon_dma_term(&avalon_dev->avalon_dma);
+
+ term_interrupts(pci_dev);
+
+ pci_release_regions(pci_dev);
+ pci_disable_device(pci_dev);
+
+ kfree(avalon_dev);
+}
+
+static struct pci_device_id pci_ids[] = {
+ { PCI_DEVICE(AVALON_DRV_PCI_VENDOR_ID, AVALON_DRV_PCI_DEVICE_ID) },
+ { 0 }
+};
+
+static struct pci_driver dma_driver_ops = {
+ .name = DRIVER_NAME,
+ .id_table = pci_ids,
+ .probe = avalon_pci_probe,
+ .remove = avalon_pci_remove,
+};
+
+static int __init avalon_drv_init(void)
+{
+ return pci_register_driver(&dma_driver_ops);
+}
+
+static void __exit avalon_drv_exit(void)
+{
+ pci_unregister_driver(&dma_driver_ops);
+}
+
+module_init(avalon_drv_init);
+module_exit(avalon_drv_exit);
+
+MODULE_AUTHOR("Alexander Gordeev <a.gordeev....@gmail.com>");
+MODULE_DESCRIPTION("Avalon DMA control driver");
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(pci, pci_ids);
diff --git a/drivers/staging/avalon-drv/avalon-drv-ioctl.c
b/drivers/staging/avalon-drv/avalon-drv-ioctl.c
new file mode 100644
index 000000000000..ca68f3a3c697
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv-ioctl.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/pci.h>
+#include <linux/uio.h>
+
+#include <uapi/linux/avalon-drv-ioctl.h>
+
+#include "avalon-drv.h"
+#include "avalon-drv-xfer.h"
+
+static const gfp_t gfp_flags = GFP_KERNEL;
+
+long avalon_dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct avalon_dev *avalon_dev = container_of(file->private_data,
+ struct avalon_dev, misc_dev);
+ struct device *dev = &avalon_dev->pci_dev->dev;
+ 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 = 0;
+
+ dev_dbg(dev, "%s(%d) { cmd %x", __FUNCTION__, __LINE__, cmd);
+
+ switch (cmd) {
+ case IOCTL_AVALON_GET_INFO: {
+ struct avalon_ioc_info info = {
+ .mem_addr = TARGET_MEM_BASE,
+ .mem_size = TARGET_MEM_SIZE,
+ .dma_size = TARGET_DMA_SIZE,
+ .dma_size_sg = TARGET_DMA_SIZE_SG,
+ };
+
+ if (copy_to_user((void *)arg, &info, sizeof(info))) {
+ ret = -EFAULT;
+ goto done;
+ }
+
+ goto done;
+ }
+ case IOCTL_AVALON_SET_INFO:
+ ret = -EINVAL;
+ goto done;
+
+ 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]))) {
+ ret = -EFAULT;
+ goto done;
+ }
+
+ 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))) {
+ ret = -EFAULT;
+ goto done;
+ }
+
+ 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:
+ ret = -EINVAL;
+ goto done;
+ };
+
+ dev_dbg(dev,
+ "%s(%d) buf %px len %ld\nbuf_rd %px len_rd %ld\nbuf_wr %px
len_wr %ld\n",
+ __FUNCTION__, __LINE__, buf, len, buf_rd, len_rd, buf_wr,
len_wr);
+
+ switch (cmd) {
+ case IOCTL_AVALON_DMA_READ:
+ ret = xfer_rw(&avalon_dev->avalon_dma,
+ DMA_FROM_DEVICE, buf, len);
+ break;
+ case IOCTL_AVALON_DMA_WRITE:
+ ret = xfer_rw(&avalon_dev->avalon_dma,
+ DMA_TO_DEVICE, buf, len);
+ break;
+ case IOCTL_AVALON_DMA_RDWR:
+ ret = xfer_simultaneous(&avalon_dev->avalon_dma,
+ buf_rd, len_rd,
+ buf_wr, len_wr);
+ break;
+
+ case IOCTL_AVALON_DMA_READ_SG:
+ ret = xfer_rw_sg(&avalon_dev->avalon_dma,
+ DMA_FROM_DEVICE, buf, len, false);
+ break;
+ case IOCTL_AVALON_DMA_WRITE_SG:
+ ret = xfer_rw_sg(&avalon_dev->avalon_dma,
+ DMA_TO_DEVICE, buf, len, false);
+ break;
+ case IOCTL_AVALON_DMA_READ_SG_SMP:
+ ret = xfer_rw_sg(&avalon_dev->avalon_dma,
+ DMA_FROM_DEVICE, buf, len, true);
+ break;
+ case IOCTL_AVALON_DMA_WRITE_SG_SMP:
+ ret = xfer_rw_sg(&avalon_dev->avalon_dma,
+ DMA_TO_DEVICE, buf, len, true);
+ break;
+ case IOCTL_AVALON_DMA_RDWR_SG:
+ ret = xfer_simultaneous_sg(&avalon_dev->avalon_dma,
+ buf_rd, len_rd,
+ buf_wr, len_wr);
+ break;
+
+ default:
+ BUG();
+ ret = -EINVAL;
+ };
+
+done:
+ dev_dbg(dev, "%s(%d) } = %d", __FUNCTION__, __LINE__, ret);
+
+ return ret;
+}
diff --git a/drivers/staging/avalon-drv/avalon-drv-ioctl.h
b/drivers/staging/avalon-drv/avalon-drv-ioctl.h
new file mode 100644
index 000000000000..149428c25c2b
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv-ioctl.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#ifndef __AVALON_DRV_IOCTL_H__
+#define __AVALON_DRV_IOCTL_H__
+
+long avalon_dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+
+#endif
diff --git a/drivers/staging/avalon-drv/avalon-drv-mmap.c
b/drivers/staging/avalon-drv/avalon-drv-mmap.c
new file mode 100644
index 000000000000..7af2f70c961e
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv-mmap.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/pci.h>
+
+#include "avalon-drv.h"
+#include "avalon-drv-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;
+ struct device *dev = sg_buf->dev;
+
+ dev_dbg(dev, "%s(%d) vma %px sg_buf %px",
+ __FUNCTION__, __LINE__, vma, sg_buf);
+
+ 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 *avalon_dev = container_of(file->private_data,
+ struct avalon_dev, misc_dev);
+ struct device *dev = &avalon_dev->pci_dev->dev;
+ 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;
+
+ dev_dbg(dev, "%s(%d) { vm_pgoff %08lx vm_flags %08lx, size %lu",
+ __FUNCTION__, __LINE__, vma->vm_pgoff, vma->vm_flags, size);
+
+ if (!(IS_ALIGNED(addr, PAGE_SIZE) && IS_ALIGNED(size, PAGE_SIZE)))
+ return -EINVAL;
+ if ((vma->vm_pgoff * PAGE_SIZE + size) > TARGET_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)) {
+ ret = PTR_ERR(sg_buf);
+ goto sg_buf_alloc_err;
+ }
+
+ for (i = 0; size > 0; i++) {
+ ret = vm_insert_page(vma, addr, sg_buf->pages[i]);
+ if (ret)
+ goto ins_page_err;
+
+ addr += PAGE_SIZE;
+ size -= PAGE_SIZE;
+ };
+
+ vma->vm_private_data = sg_buf;
+
+ dev_dbg(dev, "%s(%d) } vma %px sg_buf %px",
+ __FUNCTION__, __LINE__, vma, sg_buf);
+
+ return 0;
+
+ins_page_err:
+ dma_sg_buf_free(sg_buf);
+
+sg_buf_alloc_err:
+ dev_dbg(dev, "%s(%d) } vma %px err %d",
+ __FUNCTION__, __LINE__, vma, ret);
+
+ return ret;
+}
diff --git a/drivers/staging/avalon-drv/avalon-drv-mmap.h
b/drivers/staging/avalon-drv/avalon-drv-mmap.h
new file mode 100644
index 000000000000..8ec7d9692217
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv-mmap.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#ifndef __AVALON_DRV_MMAP_H__
+#define __AVALON_DRV_MMAP_H__
+
+int avalon_dev_mmap(struct file *file, struct vm_area_struct *vma);
+
+#endif
diff --git a/drivers/staging/avalon-drv/avalon-drv-sg-buf.c
b/drivers/staging/avalon-drv/avalon-drv-sg-buf.c
new file mode 100644
index 000000000000..f8d76a055bba
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv-sg-buf.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#include <linux/kernel.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+
+#include "avalon-drv-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);
+ /* Dont over allocate*/
+ 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;
+ /* size is already page aligned */
+ buf->num_pages = size >> PAGE_SHIFT;
+
+ buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *),
+ GFP_KERNEL | __GFP_ZERO);
+ if (!buf->pages)
+ goto fail_pages_array_alloc;
+
+ ret = dma_sg_alloc_compacted(buf, gfp_flags);
+ if (ret)
+ goto fail_pages_alloc;
+
+ ret = sg_alloc_table_from_pages(&buf->sgt, buf->pages,
+ buf->num_pages, 0, size,
+ GFP_KERNEL);
+ if (ret)
+ goto fail_table_alloc;
+
+ 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 fail_map;
+
+ buf->vaddr = vm_map_ram(buf->pages, buf->num_pages, -1, PAGE_KERNEL);
+ if (!buf->vaddr)
+ goto fail_vm_map;
+
+ return buf;
+
+fail_vm_map:
+ dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
+ buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+fail_map:
+ put_device(buf->dev);
+ sg_free_table(&buf->sgt);
+fail_table_alloc:
+ num_pages = buf->num_pages;
+ while (num_pages--)
+ __free_page(buf->pages[num_pages]);
+fail_pages_alloc:
+ kvfree(buf->pages);
+fail_pages_array_alloc:
+ 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/staging/avalon-drv/avalon-drv-sg-buf.h
b/drivers/staging/avalon-drv/avalon-drv-sg-buf.h
new file mode 100644
index 000000000000..538f9329f8df
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv-sg-buf.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#ifndef __AVALON_DRV_SG_BUF_H__
+#define __AVALON_DRV_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/staging/avalon-drv/avalon-drv-util.c
b/drivers/staging/avalon-drv/avalon-drv-util.c
new file mode 100644
index 000000000000..b7ca5aa495d2
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv-util.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/device.h>
+
+#if defined(CONFIG_DYNAMIC_DEBUG)
+static int print_mem(char *buf, size_t buf_len,
+ const void *mem, size_t mem_len)
+{
+ int ret, i, total = 0;
+
+ if (buf_len < 3)
+ return -EINVAL;
+
+ mem_len = min_t(size_t, mem_len, buf_len / 3);
+ for (i = 0; i < mem_len; i++) {
+ ret = snprintf(buf + total, buf_len - total,
+ "%02X ", ((const unsigned char *)mem)[i]);
+ if (ret < 0) {
+ strcpy(buf, "--");
+ return ret;
+ }
+ total += ret;
+ }
+
+ buf[total] = 0;
+
+ return total;
+}
+
+void dump_mem(struct device *dev, void *data, size_t len)
+{
+ char buf[256];
+ int n;
+
+ n = snprintf(buf, sizeof(buf),
+ "%s(%d): %px [ ",
+ __FUNCTION__, __LINE__, data);
+
+ print_mem(buf + n, sizeof(buf) - n, data, len);
+
+ dev_dbg(dev, "%s(%d): %s]\n", __FUNCTION__, __LINE__, buf);
+}
+#else
+void dump_mem(struct device *dev, void *data, size_t len)
+{
+}
+#endif
diff --git a/drivers/staging/avalon-drv/avalon-drv-util.h
b/drivers/staging/avalon-drv/avalon-drv-util.h
new file mode 100644
index 000000000000..113115b7e59d
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv-util.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#ifndef __AVALON_DRV_UTIL_H__
+#define __AVALON_DRV_UTIL_H__
+
+void dump_mem(struct device *dev, void *data, size_t len);
+
+#endif
diff --git a/drivers/staging/avalon-drv/avalon-drv-xfer.c
b/drivers/staging/avalon-drv/avalon-drv-xfer.c
new file mode 100644
index 000000000000..a4e305708308
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv-xfer.c
@@ -0,0 +1,655 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#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 "avalon-drv.h"
+#include "avalon-drv-sg-buf.h"
+#include "avalon-drv-util.h"
+
+static const gfp_t gfp_flags = GFP_KERNEL;
+static const size_t dma_size = TARGET_DMA_SIZE;
+static const int nr_dma_reps = 2;
+static const int dmas_per_cpu = 8;
+
+char *__dir_str[] = {
+ [DMA_BIDIRECTIONAL] = "DMA_BIDIRECTIONAL",
+ [DMA_TO_DEVICE] = "DMA_TO_DEVICE",
+ [DMA_FROM_DEVICE] = "DMA_FROM_DEVICE",
+ [DMA_NONE] = "DMA_NONE",
+};
+
+struct xfer_callback_info {
+ struct device *dev;
+ struct completion completion;
+ atomic_t counter;
+ ktime_t kt_start;
+};
+
+static void init_callback_info(struct xfer_callback_info *info,
+ struct device *dev,
+ int value)
+{
+ info->dev = dev;
+ init_completion(&info->completion);
+
+ atomic_set(&info->counter, value);
+ smp_wmb();
+
+ info->kt_start = ktime_get();
+}
+
+static int xfer_callback(struct xfer_callback_info *info, const char *pfx)
+{
+ s64 time_us = ktime_us_delta(ktime_get(), info->kt_start);
+ int ret;
+
+ smp_rmb();
+ if (atomic_dec_and_test(&info->counter)) {
+ complete(&info->completion);
+ ret = 0;
+ } else {
+ ret = 1;
+ }
+
+ dev_dbg(info->dev, "%s_%s(%d) done = %d in %lli us",
+ pfx, __FUNCTION__, __LINE__, ret, time_us);
+
+ return ret;
+}
+
+static void rd_xfer_callback(void *dma_async_param)
+{
+ struct xfer_callback_info *info = dma_async_param;
+
+ xfer_callback(info, "rd");
+
+}
+
+static void wr_xfer_callback(void *dma_async_param)
+{
+ struct xfer_callback_info *info = dma_async_param;
+
+ xfer_callback(info, "wr");
+}
+
+int xfer_rw(struct avalon_dma *avalon_dma,
+ enum dma_data_direction dir,
+ void __user *user_buf, size_t user_len)
+{
+ struct device *dev = avalon_dma->dev;
+ dma_addr_t dma_addr;
+ void *buf;
+ struct xfer_callback_info info;
+ void (*xfer_callback)(void *dma_async_param);
+ int ret;
+ int i;
+
+ const size_t size = dma_size;
+ const int nr_reps = nr_dma_reps;
+
+ dev_dbg(dev, "%s(%d) { dir %s",
+ __FUNCTION__, __LINE__, __dir_str[dir]);
+
+ if (user_len < size) {
+ ret = -EINVAL;
+ goto mem_len_err;
+ } else {
+ user_len = size;
+ }
+
+ switch (dir) {
+ case DMA_TO_DEVICE:
+ xfer_callback = wr_xfer_callback;
+ break;
+ case DMA_FROM_DEVICE:
+ xfer_callback = rd_xfer_callback;
+ break;
+ default:
+ BUG();
+ ret = -EINVAL;
+ goto dma_dir_err;
+ }
+
+ buf = kmalloc(size, gfp_flags);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto mem_alloc_err;
+ }
+
+ memset(buf, 0, size);
+
+ if (dir == DMA_TO_DEVICE) {
+ if (copy_from_user(buf, user_buf, user_len)) {
+ ret = -EFAULT;
+ goto cp_from_user_err;
+ }
+ }
+
+ dma_addr = dma_map_single(dev, buf, size, dir);
+ if (dma_mapping_error(dev, dma_addr)) {
+ ret = -ENOMEM;
+ goto dma_alloc_err;
+ }
+
+ init_callback_info(&info, dev, nr_reps);
+
+ dev_dbg(dev, "%s(%d) dma_addr %08llx size %lu dir %d reps = %d",
+ __FUNCTION__, __LINE__, dma_addr, size, dir, nr_reps);
+
+ for (i = 0; i < nr_reps; i++) {
+ ret = avalon_dma_submit_xfer(avalon_dma,
+ dir,
+ TARGET_MEM_BASE,
+ dma_addr, size,
+ xfer_callback, &info);
+ if (ret)
+ goto dma_submit_err;
+ }
+
+ ret = avalon_dma_issue_pending(avalon_dma);
+ if (ret)
+ goto issue_pending_err;
+
+ ret = wait_for_completion_interruptible(&info.completion);
+ if (ret)
+ goto wait_err;
+
+ if (dir == DMA_FROM_DEVICE) {
+ if (copy_to_user(user_buf, buf, user_len))
+ ret = -EFAULT;
+ }
+
+wait_err:
+issue_pending_err:
+dma_submit_err:
+ dma_unmap_single(dev, dma_addr, size, dir);
+
+dma_alloc_err:
+cp_from_user_err:
+ kfree(buf);
+
+mem_alloc_err:
+dma_dir_err:
+mem_len_err:
+ dev_dbg(dev, "%s(%d) } = %d", __FUNCTION__, __LINE__, ret);
+
+ return ret;
+}
+
+int xfer_simultaneous(struct avalon_dma *avalon_dma,
+ void __user *user_buf_rd, size_t user_len_rd,
+ void __user *user_buf_wr, size_t user_len_wr)
+{
+ struct device *dev = avalon_dma->dev;
+ dma_addr_t dma_addr_rd, dma_addr_wr;
+ void *buf_rd, *buf_wr;
+ struct xfer_callback_info info;
+ int ret;
+ int i;
+
+ const size_t size = dma_size;
+ const dma_addr_t target_rd = TARGET_MEM_BASE;
+ const dma_addr_t target_wr = target_rd + size;
+ const int nr_reps = nr_dma_reps;
+
+ dev_dbg(dev, "%s(%d) {", __FUNCTION__, __LINE__);
+
+ if (user_len_rd < size) {
+ ret = -EINVAL;
+ goto mem_len_err;
+ } else {
+ user_len_rd = size;
+ }
+
+ if (user_len_wr < size) {
+ ret = -EINVAL;
+ goto mem_len_err;
+ } else {
+ user_len_wr = size;
+ }
+
+ buf_rd = kmalloc(size, gfp_flags);
+ if (!buf_rd) {
+ ret = -ENOMEM;
+ goto rd_mem_alloc_err;
+ }
+
+ buf_wr = kmalloc(size, gfp_flags);
+ if (!buf_wr) {
+ ret = -ENOMEM;
+ goto wr_mem_alloc_err;
+ }
+
+ memset(buf_rd, 0, size);
+ memset(buf_wr, 0, size);
+
+ if (copy_from_user(buf_wr, user_buf_wr, user_len_wr)) {
+ ret = -EFAULT;
+ goto cp_from_user_err;
+ }
+
+ dma_addr_rd = dma_map_single(dev, buf_rd, size, DMA_FROM_DEVICE);
+ if (dma_mapping_error(dev, dma_addr_rd)) {
+ ret = -ENOMEM;
+ goto rd_dma_map_err;
+ }
+
+ dma_addr_wr = dma_map_single(dev, buf_wr, size, DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, dma_addr_rd)) {
+ ret = -ENOMEM;
+ goto wr_dma_map_err;
+ }
+
+ init_callback_info(&info, dev, 2 * nr_reps);
+
+ for (i = 0; i < nr_reps; i++) {
+ ret = avalon_dma_submit_xfer(avalon_dma,
+ DMA_TO_DEVICE,
+ target_wr, dma_addr_wr, size,
+ wr_xfer_callback, &info);
+ if (ret)
+ goto rd_dma_submit_err;
+
+ ret = avalon_dma_submit_xfer(avalon_dma,
+ DMA_FROM_DEVICE,
+ target_rd, dma_addr_rd, size,
+ rd_xfer_callback, &info);
+ BUG_ON(ret);
+ if (ret)
+ goto wr_dma_submit_err;
+ }
+
+ ret = avalon_dma_issue_pending(avalon_dma);
+ BUG_ON(ret);
+ if (ret)
+ goto issue_pending_err;
+
+ dev_dbg(dev,
+ "%s(%d) dma_addr %08llx/%08llx rd_size %lu wr_size %lu",
+ __FUNCTION__, __LINE__,
+ dma_addr_rd, dma_addr_wr, size, size);
+
+ ret = wait_for_completion_interruptible(&info.completion);
+ if (ret)
+ goto wait_err;
+
+ if (copy_to_user(user_buf_rd, buf_rd, user_len_rd))
+ ret = -EFAULT;
+
+wait_err:
+issue_pending_err:
+wr_dma_submit_err:
+rd_dma_submit_err:
+ dma_unmap_single(dev, dma_addr_wr, size, DMA_TO_DEVICE);
+
+wr_dma_map_err:
+ dma_unmap_single(dev, dma_addr_rd, size, DMA_FROM_DEVICE);
+
+rd_dma_map_err:
+cp_from_user_err:
+ kfree(buf_wr);
+
+wr_mem_alloc_err:
+ kfree(buf_rd);
+
+rd_mem_alloc_err:
+mem_len_err:
+ dev_dbg(dev, "%s(%d) } = %d", __FUNCTION__, __LINE__, ret);
+
+ return ret;
+}
+
+static int kthread_xfer_rw_sg(struct avalon_dma *avalon_dma,
+ enum dma_data_direction dir,
+ dma_addr_t dev_addr, struct sg_table *sgt,
+ void (*xfer_callback)(void *dma_async_param))
+{
+ struct device *dev = avalon_dma->dev;
+ struct xfer_callback_info info;
+ int ret = 0;
+ int i;
+
+ const int nr_reps = nr_dma_reps;
+
+ while (!kthread_should_stop()) {
+ init_callback_info(&info, dev, nr_reps);
+
+ for (i = 0; i < nr_reps; i++) {
+ ret = avalon_dma_submit_xfer_sg(avalon_dma,
+ dir,
+ dev_addr, sgt,
+ xfer_callback, &info);
+ if (ret) {
+ /*
+ * Ideally, kind of avalon_dma_cancel() should
+ * be called here to avoid running out of descs
+ * (ones stuck in "submitted" list since it
+ * never gets processed)
+ *
+ * However, a call to avalon_dma_issue_pending()
+ * would do the job and let all outstanding
+ * descs processed and moved back to "allocated"
+ * queue in the end of the day.
+ *
+ * Leave it as is as a showcase of "allocated"
+ * list empty and "submitted" list full and
+ * unprocessed.
+ */
+ goto err;
+ }
+ }
+
+ ret = avalon_dma_issue_pending(avalon_dma);
+ if (ret)
+ goto err;
+
+ ret = wait_for_completion_interruptible(&info.completion);
+ if (ret)
+ goto err;
+ }
+
+ return 0;
+
+err:
+ dev_dbg(dev, "%s(%d) cpu %d avalon_dma_submit_xfer_sg() %d",
+ __FUNCTION__, __LINE__, smp_processor_id(), ret);
+
+ while (!kthread_should_stop())
+ cond_resched();
+
+ return ret;
+}
+
+struct kthread_xfer_rw_sg_data {
+ struct avalon_dma *avalon_dma;
+ enum dma_data_direction dir;
+ dma_addr_t dev_addr;
+ struct sg_table *sgt;
+ void (*xfer_callback)(void *dma_async_param);
+};
+
+static int __kthread_xfer_rw_sg(void *_data)
+{
+ struct kthread_xfer_rw_sg_data *data = _data;
+
+ return kthread_xfer_rw_sg(data->avalon_dma,
+ data->dir,
+ data->dev_addr, data->sgt,
+ data->xfer_callback);
+}
+
+static int __xfer_rw_sg_smp(struct avalon_dma *avalon_dma,
+ enum dma_data_direction dir,
+ dma_addr_t dev_addr, struct sg_table *sgt,
+ void (*xfer_callback)(void *dma_async_param))
+{
+ struct kthread_xfer_rw_sg_data data = {
+ avalon_dma,
+ dir,
+ dev_addr,
+ sgt,
+ xfer_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(sizeof(tasks[0]) * nr_tasks, 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, "av-dma-sg-%d-%d", cpu, n);
+ if (IS_ERR(task)) {
+ ret = PTR_ERR(task);
+ goto kthread_err;
+ }
+
+ kthread_bind(task, cpu);
+
+ tasks[i] = task;
+ i++;
+ }
+ }
+
+ for (i = 0; i < nr_tasks; i++)
+ wake_up_process(tasks[i]);
+
+ /*
+ * 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:
+ for (i = 0; i < nr_tasks; i++)
+ kthread_stop(tasks[i]);
+
+ kfree(tasks);
+
+ return ret;
+}
+
+static int __xfer_rw_sg(struct avalon_dma *avalon_dma,
+ enum dma_data_direction dir,
+ dma_addr_t dev_addr, struct sg_table *sgt,
+ void (*xfer_callback)(void *dma_async_param))
+{
+ struct device *dev = avalon_dma->dev;
+ struct xfer_callback_info info;
+ int ret = 0;
+ int i;
+
+ const int nr_reps = nr_dma_reps;
+
+ init_callback_info(&info, dev, nr_reps);
+
+ for (i = 0; i < nr_reps; i++) {
+ ret = avalon_dma_submit_xfer_sg(avalon_dma,
+ dir,
+ dev_addr, sgt,
+ xfer_callback, &info);
+ if (ret)
+ return ret;
+ }
+
+ ret = avalon_dma_issue_pending(avalon_dma);
+ if (ret)
+ return ret;
+
+ 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_rw_sg(struct avalon_dma *avalon_dma,
+ enum dma_data_direction dir,
+ void __user *user_buf, size_t user_len,
+ bool is_smp)
+{
+ struct device *dev = avalon_dma->dev;
+ int (*xfer)(struct avalon_dma *avalon_dma,
+ enum dma_data_direction dir,
+ dma_addr_t dev_addr,
+ struct sg_table *sgt,
+ void (*xfer_callback)(void *dma_async_param));
+ void (*xfer_callback)(void *dma_async_param);
+ struct vm_area_struct *vma;
+ struct dma_sg_buf *sg_buf;
+ dma_addr_t dma_addr;
+ int ret;
+
+ dev_dbg(dev, "%s(%d) { dir %s smp %d",
+ __FUNCTION__, __LINE__, __dir_str[dir], is_smp);
+
+ 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_rw_sg_smp;
+ else
+ xfer = __xfer_rw_sg;
+
+ if (dir == DMA_FROM_DEVICE)
+ xfer_callback = rd_xfer_callback;
+ else
+ xfer_callback = wr_xfer_callback;
+
+ dma_addr = TARGET_MEM_BASE + vma->vm_pgoff * PAGE_SIZE;
+
+ if (dir == DMA_TO_DEVICE)
+ dump_mem(dev, sg_buf->vaddr, 16);
+
+ dma_sync_sg_for_device(dev,
+ sg_buf->sgt.sgl, sg_buf->sgt.nents,
+ sg_buf->dma_dir);
+
+ ret = xfer(avalon_dma, dir, dma_addr, &sg_buf->sgt, xfer_callback);
+ if (ret)
+ goto xfer_err;
+
+ dma_sync_sg_for_cpu(dev,
+ sg_buf->sgt.sgl, sg_buf->sgt.nents,
+ sg_buf->dma_dir);
+
+ if (dir == DMA_FROM_DEVICE)
+ dump_mem(dev, sg_buf->vaddr, 16);
+
+xfer_err:
+ dev_dbg(dev, "%s(%d) } = %d", __FUNCTION__, __LINE__, ret);
+
+ return ret;
+}
+
+int xfer_simultaneous_sg(struct avalon_dma *avalon_dma,
+ void __user *user_buf_rd, size_t user_len_rd,
+ void __user *user_buf_wr, size_t user_len_wr)
+{
+ struct device *dev = avalon_dma->dev;
+ dma_addr_t dma_addr_rd, dma_addr_wr;
+ struct xfer_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;
+
+ const int nr_reps = nr_dma_reps;
+
+ dev_dbg(dev, "%s(%d) {", __FUNCTION__, __LINE__);
+
+ 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 = TARGET_MEM_BASE + vma_rd->vm_pgoff * PAGE_SIZE;
+ dma_addr_wr = TARGET_MEM_BASE + vma_wr->vm_pgoff * PAGE_SIZE;
+
+ init_callback_info(&info, dev, 2 * nr_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_reps; i++) {
+ ret = avalon_dma_submit_xfer_sg(avalon_dma,
+ DMA_TO_DEVICE,
+ dma_addr_wr,
+ &sg_buf_wr->sgt,
+ wr_xfer_callback, &info);
+ if (ret)
+ goto dma_submit_rd_err;
+
+ ret = avalon_dma_submit_xfer_sg(avalon_dma,
+ DMA_FROM_DEVICE,
+ dma_addr_rd,
+ &sg_buf_rd->sgt,
+ rd_xfer_callback, &info);
+ if (ret)
+ goto dma_submit_wr_err;
+ }
+
+ ret = avalon_dma_issue_pending(avalon_dma);
+ if (ret)
+ goto issue_pending_err;
+
+ ret = wait_for_completion_interruptible(&info.completion);
+ if (ret)
+ goto wait_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);
+
+wait_err:
+issue_pending_err:
+dma_submit_wr_err:
+dma_submit_rd_err:
+ dev_dbg(dev, "%s(%d) } = %d", __FUNCTION__, __LINE__, ret);
+
+ return ret;
+}
diff --git a/drivers/staging/avalon-drv/avalon-drv-xfer.h
b/drivers/staging/avalon-drv/avalon-drv-xfer.h
new file mode 100644
index 000000000000..5bd76cc393d3
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv-xfer.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#ifndef __AVALON_DRV_XFER_H__
+#define __AVALON_DRV_XFER_H__
+
+int xfer_rw(struct avalon_dma *avalon_dma,
+ enum dma_data_direction dir,
+ void __user *user_buf, size_t user_len);
+int xfer_simultaneous(struct avalon_dma *avalon_dma,
+ void __user *user_buf_rd, size_t user_len_rd,
+ void __user *user_buf_wr, size_t user_len_wr);
+int xfer_rw_sg(struct avalon_dma *avalon_dma,
+ enum dma_data_direction dir,
+ void __user *user_buf, size_t user_len,
+ bool is_smp);
+int xfer_simultaneous_sg(struct avalon_dma *avalon_dma,
+ void __user *user_buf_rd, size_t user_len_rd,
+ void __user *user_buf_wr, size_t user_len_wr);
+
+#endif
diff --git a/drivers/staging/avalon-drv/avalon-drv.h
b/drivers/staging/avalon-drv/avalon-drv.h
new file mode 100644
index 000000000000..290c75ba4c77
--- /dev/null
+++ b/drivers/staging/avalon-drv/avalon-drv.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#ifndef __AVALON_DRV_H__
+#define __AVALON_DRV_H__
+
+#include <linux/miscdevice.h>
+
+#include <linux/avalon-dma.h>
+
+#define DRIVER_NAME "avalon-drv"
+
+struct avalon_dev {
+ struct pci_dev *pci_dev;
+ struct avalon_dma avalon_dma;
+ struct miscdevice misc_dev;
+};
+
+#endif
diff --git a/include/uapi/linux/avalon-drv-ioctl.h
b/include/uapi/linux/avalon-drv-ioctl.h
new file mode 100644
index 000000000000..af676b41a50f
--- /dev/null
+++ b/include/uapi/linux/avalon-drv-ioctl.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Avalon DMA driver
+ *
+ * Author: Alexander Gordeev <a.gordeev....@gmail.com>
+ */
+#ifndef _UAPI_LINUX_AVALON_DRV_IOCTL_H__
+#define _UAPI_LINUX_AVALON_DRV_IOCTL_H__
+
+struct avalon_ioc_info {
+ size_t mem_addr;
+ size_t mem_size;
+ size_t dma_size;
+ size_t dma_size_sg;
+} __attribute((packed));
+
+#define AVALON_IOC 'V'
+
+#define IOCTL_AVALON_GET_INFO _IOR(AVALON_IOC, 0, struct
avalon_ioc_info)
+#define IOCTL_AVALON_SET_INFO _IOR(AVALON_IOC, 1, struct
avalon_ioc_info)
+#define IOCTL_AVALON_DMA_READ _IOR(AVALON_IOC, 2, struct iovec)
+#define IOCTL_AVALON_DMA_WRITE _IOW(AVALON_IOC, 3, struct iovec)
+#define IOCTL_AVALON_DMA_RDWR _IOWR(AVALON_IOC, 4, struct iovec[2])
+#define IOCTL_AVALON_DMA_READ_SG _IOR(AVALON_IOC, 5, struct iovec)
+#define IOCTL_AVALON_DMA_WRITE_SG _IOW(AVALON_IOC, 6, struct iovec)
+#define IOCTL_AVALON_DMA_RDWR_SG _IOWR(AVALON_IOC, 7, struct iovec[2])
+#define IOCTL_AVALON_DMA_READ_SG_SMP _IOR(AVALON_IOC, 8, struct iovec)
+#define IOCTL_AVALON_DMA_WRITE_SG_SMP _IOW(AVALON_IOC, 9, struct iovec)
+
+#endif
--
2.22.0
