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Message-ID: <4185a20a-1f33-dbf7-0b19-979c8cf54cce@intel.com>
Date: Fri, 16 Sep 2022 13:52:14 -0700
From: Dave Jiang <dave.jiang@...el.com>
To: Lizhi Hou <lizhi.hou@....com>, vkoul@...nel.org,
dmaengine@...r.kernel.org, linux-kernel@...r.kernel.org,
trix@...hat.com
Cc: max.zhen@....com, sonal.santan@....com, larry.liu@....com,
brian.xu@....com
Subject: Re: [PATCH V2 XDMA 1/1] dmaengine: xilinx: xdma: add xilinx xdma
driver
On 9/16/2022 1:10 PM, Lizhi Hou wrote:
>
> On 9/16/22 08:39, Dave Jiang wrote:
>>
>> On 9/16/2022 8:26 AM, Lizhi Hou wrote:
>>> Add driver to enable PCIe board which uses XDMA (the DMA/Bridge
>>> Subsystem
>>> for PCI Express). For example, Xilinx Alveo PCIe devices.
>>> https://www.xilinx.com/products/boards-and-kits/alveo.html
>>>
>>> The XDMA engine support up to 4 Host to Card (H2C) and 4 Card to
>>> Host (C2H)
>>> channels. Memory transfers are specified on a per-channel basis in
>>> descriptor linked lists, which the DMA fetches from host memory and
>>> processes. Events such as descriptor completion and errors are signaled
>>> using interrupts. The hardware detail is provided by
>>> https://docs.xilinx.com/r/en-US/pg195-pcie-dma/Introduction
>>>
>>> This driver implements dmaengine APIs.
>>> - probe the available DMA channels
>>> - use dma_slave_map for channel lookup
>>> - use virtual channel to manage dmaengine tx descriptors
>>> - implement device_prep_slave_sg callback to handle host
>>> scatter gather
>>> list
>>> - implement device_config to config device address for DMA
>>> transfer
>>>
>>> Signed-off-by: Lizhi Hou <lizhi.hou@....com>
>>> Signed-off-by: Sonal Santan <sonal.santan@....com>
>>> Signed-off-by: Max Zhen <max.zhen@....com>
>>> Signed-off-by: Brian Xu <brian.xu@....com>
>>> ---
>>> MAINTAINERS | 10 +
>>> drivers/dma/Kconfig | 13 +
>>> drivers/dma/xilinx/Makefile | 1 +
>>> drivers/dma/xilinx/xdma-regs.h | 171 +++++
>>> drivers/dma/xilinx/xdma.c | 982
>>> +++++++++++++++++++++++++
>>> include/linux/platform_data/amd_xdma.h | 34 +
>>> 6 files changed, 1211 insertions(+)
>>> create mode 100644 drivers/dma/xilinx/xdma-regs.h
>>> create mode 100644 drivers/dma/xilinx/xdma.c
>>> create mode 100644 include/linux/platform_data/amd_xdma.h
>>>
>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>> index e8c52d0192a6..c1be0b2e378a 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -21683,6 +21683,16 @@ F:
>>> Documentation/devicetree/bindings/media/xilinx/
>>> F: drivers/media/platform/xilinx/
>>> F: include/uapi/linux/xilinx-v4l2-controls.h
>>> +XILINX XDMA DRIVER
>>> +M: Lizhi Hou <lizhi.hou@....com>
>>> +M: Brian Xu <brian.xu@....com>
>>> +M: Raj Kumar Rampelli <raj.kumar.rampelli@....com>
>>> +L: dmaengine@...r.kernel.org
>>> +S: Supported
>>> +F: drivers/dma/xilinx/xdma-regs.h
>>> +F: drivers/dma/xilinx/xdma.c
>>> +F: include/linux/platform_data/amd_xdma.h
>>> +
>>> XILINX ZYNQMP DPDMA DRIVER
>>> M: Hyun Kwon <hyun.kwon@...inx.com>
>>> M: Laurent Pinchart <laurent.pinchart@...asonboard.com>
>>> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
>>> index d5de3f77d3aa..4d90f2f51655 100644
>>> --- a/drivers/dma/Kconfig
>>> +++ b/drivers/dma/Kconfig
>>> @@ -733,6 +733,19 @@ config XILINX_ZYNQMP_DPDMA
>>> driver provides the dmaengine required by the DisplayPort
>>> subsystem
>>> display driver.
>>> +config XILINX_XDMA
>>> + tristate "Xilinx DMA/Bridge Subsystem DMA Engine"
>>> + select DMA_ENGINE
>>> + select DMA_VIRTUAL_CHANNELS
>>> + select REGMAP_MMIO
>>> + help
>>> + Enable support for Xilinx DMA/Bridge Subsystem DMA engine.
>>> The DMA
>>> + provides high performance block data movement between Host
>>> memory
>>> + and the DMA subsystem. These direct memory transfers can be
>>> both in
>>> + the Host to Card (H2C) and Card to Host (C2H) transfers.
>>> + The core also provides up to 16 user interrupt wires that
>>> generate
>>> + interrupts to the host.
>>> +
>>> # driver files
>>> source "drivers/dma/bestcomm/Kconfig"
>>> diff --git a/drivers/dma/xilinx/Makefile
>>> b/drivers/dma/xilinx/Makefile
>>> index 767bb45f641f..c7a538a56643 100644
>>> --- a/drivers/dma/xilinx/Makefile
>>> +++ b/drivers/dma/xilinx/Makefile
>>> @@ -2,3 +2,4 @@
>>> obj-$(CONFIG_XILINX_DMA) += xilinx_dma.o
>>> obj-$(CONFIG_XILINX_ZYNQMP_DMA) += zynqmp_dma.o
>>> obj-$(CONFIG_XILINX_ZYNQMP_DPDMA) += xilinx_dpdma.o
>>> +obj-$(CONFIG_XILINX_XDMA) += xdma.o
>>> diff --git a/drivers/dma/xilinx/xdma-regs.h
>>> b/drivers/dma/xilinx/xdma-regs.h
>>> new file mode 100644
>>> index 000000000000..c42df0ed4aca
>>> --- /dev/null
>>> +++ b/drivers/dma/xilinx/xdma-regs.h
>>> @@ -0,0 +1,171 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-or-later */
>>> +/*
>>> + * Copyright (C) 2017-2020 Xilinx, Inc. All rights reserved.
>>> + * Copyright (C) 2022 Advanced Micro Devices, Inc. All rights
>>> reserved.
>>> + */
>>> +
>>> +#ifndef __DMA_XDMA_REGS_H
>>> +#define __DMA_XDMA_REGS_H
>>> +
>>> +/* The length of register space exposed to host */
>>> +#define XDMA_REG_SPACE_LEN 65536
>>> +
>>> +/*
>>> + * maximum number of DMA channels for each direction:
>>> + * Host to Card (H2C) or Card to Host (C2H)
>>> + */
>>> +#define XDMA_MAX_CHANNELS 4
>>> +
>>> +/* macros to get higher and lower 32-bit address */
>>> +#define XDMA_HI_ADDR_MASK GENMASK_ULL(63, 32)
>>> +#define XDMA_LO_ADDR_MASK GENMASK_ULL(31, 0)
>>> +
>>> +/*
>>> + * macros to define the number of descriptor blocks can be used in one
>>> + * DMA transfer request.
>>> + * the DMA engine uses a linked list of descriptor blocks that
>>> specify the
>>> + * source, destination, and length of the DMA transfers.
>>> + */
>>> +#define XDMA_DESC_BLOCK_NUM BIT(7)
>>> +#define XDMA_DESC_BLOCK_MASK (XDMA_DESC_BLOCK_NUM - 1)
>>> +
>>> +/* descriptor definitions */
>>> +#define XDMA_DESC_ADJACENT BIT(5)
>>> +#define XDMA_DESC_ADJACENT_MASK (XDMA_DESC_ADJACENT - 1)
>>> +#define XDMA_DESC_MAGIC 0xad4bUL
>>> +#define XDMA_DESC_MAGIC_SHIFT 16
>>> +#define XDMA_DESC_ADJACENT_SHIFT 8
>>> +#define XDMA_DESC_STOPPED BIT(0)
>>> +#define XDMA_DESC_COMPLETED BIT(1)
>>> +#define XDMA_DESC_BLEN_BITS 28
>>> +#define XDMA_DESC_BLEN_MAX (BIT(XDMA_DESC_BLEN_BITS) -
>>> PAGE_SIZE)
>>> +
>>> +/* macros to construct the descriptor control word */
>>> +#define XDMA_DESC_CONTROL(adjacent, flag) \
>>> + ((XDMA_DESC_MAGIC << XDMA_DESC_MAGIC_SHIFT) | \
>>> + (((adjacent) - 1) << XDMA_DESC_ADJACENT_SHIFT) | (flag))
>>> +#define XDMA_DESC_CONTROL_LAST \
>>> + XDMA_DESC_CONTROL(1, XDMA_DESC_STOPPED | XDMA_DESC_COMPLETED)
>>> +
>>> +/*
>>> + * Descriptor for a single contiguous memory block transfer.
>>> + *
>>> + * Multiple descriptors are linked by means of the next pointer. An
>>> additional
>>> + * extra adjacent number gives the amount of extra contiguous
>>> descriptors.
>>> + *
>>> + * The descriptors are in root complex memory, and the bytes in the
>>> 32-bit
>>> + * words must be in little-endian byte ordering.
>>> + */
>>> +struct xdma_hw_desc {
>>> + __le32 control;
>>> + __le32 bytes;
>>> + __le64 src_addr;
>>> + __le64 dst_addr;
>>> + __le64 next_desc;
>>> +};
>>> +
>>> +#define XDMA_DESC_SIZE sizeof(struct xdma_hw_desc)
>>> +#define XDMA_DESC_BLOCK_SIZE (XDMA_DESC_SIZE * XDMA_DESC_ADJACENT)
>>> +#define XDMA_DESC_BLOCK_ALIGN 4096
>>> +
>>> +/*
>>> + * Channel registers
>>> + */
>>> +#define XDMA_CHAN_IDENTIFIER 0x0
>>> +#define XDMA_CHAN_CONTROL 0x4
>>> +#define XDMA_CHAN_CONTROL_W1S 0x8
>>> +#define XDMA_CHAN_CONTROL_W1C 0xc
>>> +#define XDMA_CHAN_STATUS 0x40
>>> +#define XDMA_CHAN_COMPLETED_DESC 0x48
>>> +#define XDMA_CHAN_ALIGNMENTS 0x4c
>>> +#define XDMA_CHAN_INTR_ENABLE 0x90
>>> +#define XDMA_CHAN_INTR_ENABLE_W1S 0x94
>>> +#define XDMA_CHAN_INTR_ENABLE_W1C 0x9c
>>> +
>>> +#define XDMA_CHAN_STRIDE 0x100
>>> +#define XDMA_CHAN_H2C_OFFSET 0x0
>>> +#define XDMA_CHAN_C2H_OFFSET 0x1000
>>> +#define XDMA_CHAN_H2C_TARGET 0x0
>>> +#define XDMA_CHAN_C2H_TARGET 0x1
>>> +
>>> +/* macro to check if channel is available */
>>> +#define XDMA_CHAN_MAGIC 0x1fc0
>>> +#define XDMA_CHAN_CHECK_TARGET(id, target) \
>>> + (((u32)(id) >> 16) == XDMA_CHAN_MAGIC + (target))
>>> +
>>> +/* bits of the channel control register */
>>> +#define CHAN_CTRL_RUN_STOP BIT(0)
>>> +#define CHAN_CTRL_IE_DESC_STOPPED BIT(1)
>>> +#define CHAN_CTRL_IE_DESC_COMPLETED BIT(2)
>>> +#define CHAN_CTRL_IE_DESC_ALIGN_MISMATCH BIT(3)
>>> +#define CHAN_CTRL_IE_MAGIC_STOPPED BIT(4)
>>> +#define CHAN_CTRL_IE_IDLE_STOPPED BIT(6)
>>> +#define CHAN_CTRL_IE_READ_ERROR (0x1FUL << 9)
>>> +#define CHAN_CTRL_IE_DESC_ERROR (0x1FUL << 19)
>>> +#define CHAN_CTRL_NON_INCR_ADDR BIT(25)
>>> +#define CHAN_CTRL_POLL_MODE_WB BIT(26)
>>> +
>>> +#define CHAN_CTRL_START (CHAN_CTRL_RUN_STOP | \
>>> + CHAN_CTRL_IE_DESC_STOPPED | \
>>> + CHAN_CTRL_IE_DESC_COMPLETED | \
>>> + CHAN_CTRL_IE_DESC_ALIGN_MISMATCH | \
>>> + CHAN_CTRL_IE_MAGIC_STOPPED | \
>>> + CHAN_CTRL_IE_READ_ERROR | \
>>> + CHAN_CTRL_IE_DESC_ERROR)
>>> +
>>> +/* bits of the channel interrupt enable mask */
>>> +#define CHAN_IM_DESC_ERROR BIT(19)
>>> +#define CHAN_IM_READ_ERROR BIT(9)
>>> +#define CHAN_IM_IDLE_STOPPED BIT(6)
>>> +#define CHAN_IM_MAGIC_STOPPED BIT(4)
>>> +#define CHAN_IM_DESC_COMPLETED BIT(2)
>>> +#define CHAN_IM_DESC_STOPPED BIT(1)
>>> +
>>> +#define CHAN_IM_ALL (CHAN_IM_DESC_ERROR | CHAN_IM_READ_ERROR | \
>>> + CHAN_IM_IDLE_STOPPED | CHAN_IM_MAGIC_STOPPED | \
>>> + CHAN_IM_DESC_COMPLETED | CHAN_IM_DESC_STOPPED)
>>> +
>>> +/*
>>> + * Channel SGDMA registers
>>> + */
>>> +#define XDMA_SGDMA_IDENTIFIER 0x0
>>> +#define XDMA_SGDMA_DESC_LO 0x80
>>> +#define XDMA_SGDMA_DESC_HI 0x84
>>> +#define XDMA_SGDMA_DESC_ADJ 0x88
>>> +#define XDMA_SGDMA_DESC_CREDIT 0x8c
>>> +
>>> +#define XDMA_SGDMA_BASE(chan_base) ((chan_base) + 0x4000)
>>> +
>>> +/* bits of the SG DMA control register */
>>> +#define XDMA_CTRL_RUN_STOP BIT(0)
>>> +#define XDMA_CTRL_IE_DESC_STOPPED BIT(1)
>>> +#define XDMA_CTRL_IE_DESC_COMPLETED BIT(2)
>>> +#define XDMA_CTRL_IE_DESC_ALIGN_MISMATCH BIT(3)
>>> +#define XDMA_CTRL_IE_MAGIC_STOPPED BIT(4)
>>> +#define XDMA_CTRL_IE_IDLE_STOPPED BIT(6)
>>> +#define XDMA_CTRL_IE_READ_ERROR (0x1FUL << 9)
>>> +#define XDMA_CTRL_IE_DESC_ERROR (0x1FUL << 19)
>>> +#define XDMA_CTRL_NON_INCR_ADDR BIT(25)
>>> +#define XDMA_CTRL_POLL_MODE_WB BIT(26)
>>> +
>>> +/*
>>> + * interrupt registers
>>> + */
>>> +#define XDMA_IRQ_IDENTIFIER 0x0
>>> +#define XDMA_IRQ_USER_INT_EN 0x04
>>> +#define XDMA_IRQ_USER_INT_EN_W1S 0x08
>>> +#define XDMA_IRQ_USER_INT_EN_W1C 0x0c
>>> +#define XDMA_IRQ_CHAN_INT_EN 0x10
>>> +#define XDMA_IRQ_CHAN_INT_EN_W1S 0x14
>>> +#define XDMA_IRQ_CHAN_INT_EN_W1C 0x18
>>> +#define XDMA_IRQ_USER_INT_REQ 0x40
>>> +#define XDMA_IRQ_CHAN_INT_REQ 0x44
>>> +#define XDMA_IRQ_USER_INT_PEND 0x48
>>> +#define XDMA_IRQ_CHAN_INT_PEND 0x4c
>>> +#define XDMA_IRQ_USER_VEC_NUM 0x80
>>> +#define XDMA_IRQ_CHAN_VEC_NUM 0xa0
>>> +
>>> +#define XDMA_IRQ_BASE 0x2000
>>> +#define XDMA_IRQ_VEC_SHIFT 8
>>> +
>>> +#endif /* __DMA_XDMA_REGS_H */
>>> diff --git a/drivers/dma/xilinx/xdma.c b/drivers/dma/xilinx/xdma.c
>>> new file mode 100644
>>> index 000000000000..59797ae5251c
>>> --- /dev/null
>>> +++ b/drivers/dma/xilinx/xdma.c
>>> @@ -0,0 +1,982 @@
>>> +// SPDX-License-Identifier: GPL-2.0-or-later
>>> +/*
>>> + * DMA driver for Xilinx DMA/Bridge Subsystem
>>> + *
>>> + * Copyright (C) 2017-2020 Xilinx, Inc. All rights reserved.
>>> + * Copyright (C) 2022 Advanced Micro Devices, Inc. All rights
>>> reserved.
>>> + */
>>> +
>>> +/*
>>> + * The DMA/Bridge Subsystem for PCI Express allows for the movement
>>> of data
>>> + * between Host memory and the DMA subsystem. It does this by
>>> operating on
>>> + * 'descriptors' that contain information about the source,
>>> destination and
>>> + * amount of data to transfer. These direct memory transfers can be
>>> both in
>>> + * the Host to Card (H2C) and Card to Host (C2H) transfers. The DMA
>>> can be
>>> + * configured to have a single AXI4 Master interface shared by all
>>> channels
>>> + * or one AXI4-Stream interface for each channel enabled. Memory
>>> transfers are
>>> + * specified on a per-channel basis in descriptor linked lists,
>>> which the DMA
>>> + * fetches from host memory and processes. Events such as
>>> descriptor completion
>>> + * and errors are signaled using interrupts. The core also provides
>>> up to 16
>>> + * user interrupt wires that generate interrupts to the host.
>>> + */
>>> +
>>> +#include <linux/mod_devicetable.h>
>>> +#include <linux/bitfield.h>
>>> +#include <linux/dmapool.h>
>>> +#include <linux/regmap.h>
>>> +#include <linux/dmaengine.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/platform_data/amd_xdma.h>
>>> +#include <linux/dma-mapping.h>
>>> +#include "../virt-dma.h"
>>> +#include "xdma-regs.h"
>>> +
>>> +/* mmio regmap config for all XDMA registers */
>>> +static const struct regmap_config xdma_regmap_config = {
>>> + .reg_bits = 32,
>>> + .val_bits = 32,
>>> + .reg_stride = 4,
>>> + .max_register = XDMA_REG_SPACE_LEN,
>>> +};
>>> +
>>> +/**
>>> + * struct xdma_desc_block - Descriptor block
>>> + * @virt_addr: Virtual address of block start
>>> + * @dma_addr: DMA address of block start
>>> + */
>>> +struct xdma_desc_block {
>>> + void *virt_addr;
>>> + dma_addr_t dma_addr;
>>> +};
>>> +
>>> +/**
>>> + * struct xdma_chan - Driver specific DMA channel structure
>>> + * @vchan: Virtual channel
>>> + * @xdev_hdl: Pointer to DMA device structure
>>> + * @base: Offset of channel registers
>>> + * @desc_pool: Descriptor pool
>>> + * @busy: Busy flag of the channel
>>> + * @dir: Transferring direction of the channel
>>> + * @cfg: Transferring config of the channel
>>> + * @irq: IRQ assigned to the channel
>>> + * @tasklet: Channel tasklet
>>> + */
>>> +struct xdma_chan {
>>> + struct virt_dma_chan vchan;
>>> + void *xdev_hdl;
>>> + u32 base;
>>> + struct dma_pool *desc_pool;
>>> + bool busy;
>>> + enum dma_transfer_direction dir;
>>> + struct dma_slave_config cfg;
>>> + u32 irq;
>>> + struct tasklet_struct tasklet;
>>> +};
>>> +
>>> +/**
>>> + * struct xdma_desc - DMA desc structure
>>> + * @vdesc: Virtual DMA descriptor
>>> + * @dir: Transferring direction of the request
>>> + * @dev_addr: Physical address on DMA device side
>>> + * @desc_blocks: Hardware descriptor blocks
>>> + * @dblk_num: Number of hardware descriptor blocks
>>> + * @desc_num: Number of hardware descriptors
>>> + * @completed_desc_num: Completed hardware descriptors
>>> + */
>>> +struct xdma_desc {
>>> + struct virt_dma_desc vdesc;
>>> + struct xdma_chan *chan;
>>> + enum dma_transfer_direction dir;
>>> + u64 dev_addr;
>>> + struct xdma_desc_block *desc_blocks;
>>> + u32 dblk_num;
>>> + u32 desc_num;
>>> + u32 completed_desc_num;
>>> +};
>>> +
>>> +#define XDMA_DEV_STATUS_REG_DMA BIT(0)
>>> +#define XDMA_DEV_STATUS_INIT_MSIX BIT(1)
>>> +
>>> +/**
>>> + * struct xdma_device - DMA device structure
>>> + * @pdev: Platform device pointer
>>> + * @dma_dev: DMA device structure
>>> + * @regmap: MMIO regmap for DMA registers
>>> + * @h2c_chans: Host to Card channels
>>> + * @c2h_chans: Card to Host channels
>>> + * @h2c_chan_num: Number of H2C channels
>>> + * @c2h_chan_num: Number of C2H channels
>>> + * @irq_start: Start IRQ assigned to device
>>> + * @irq_num: Number of IRQ assigned to device
>>> + * @status: Initialization status
>>> + */
>>> +struct xdma_device {
>>> + struct platform_device *pdev;
>>> + struct dma_device dma_dev;
>>> + struct regmap *regmap;
>>> + struct xdma_chan *h2c_chans;
>>> + struct xdma_chan *c2h_chans;
>>> + u32 h2c_chan_num;
>>> + u32 c2h_chan_num;
>>> + u32 irq_start;
>>> + u32 irq_num;
>>> + u32 status;
>>> +};
>>> +
>>> +#define xdma_err(xdev, fmt, args...) \
>>> + dev_err(&(xdev)->pdev->dev, fmt, ##args)
>>> +
>>> +/* Read and Write DMA registers */
>>> +static inline int xdma_read_reg(struct xdma_device *xdev, u32 base,
>>> u32 reg,
>>> + u32 *val)
>>> +{
>>> + return regmap_read(xdev->regmap, base + reg, val);
>>> +}
>>> +
>>> +static inline int xdma_write_reg(struct xdma_device *xdev, u32
>>> base, u32 reg,
>>> + u32 val)
>>> +{
>>> + return regmap_write(xdev->regmap, base + reg, val);
>>> +}
>>> +
>>> +/* Get the last desc in a desc block */
>>> +static inline void *xdma_blk_last_desc(struct xdma_desc_block *block)
>>> +{
>>> + return block->virt_addr + (XDMA_DESC_ADJACENT - 1) *
>>> XDMA_DESC_SIZE;
>>> +}
>>> +
>>> +/**
>>> + * xdma_link_desc_blocks - Link descriptor blocks for DMA transfer
>>> + * @sw_desc: Tx descriptor pointer
>>> + */
>>> +static void xdma_link_desc_blocks(struct xdma_desc *sw_desc)
>>> +{
>>> + struct xdma_desc_block *block;
>>> + u32 last_blk_desc_num, desc_control;
>>> + struct xdma_hw_desc *desc;
>>> + int i;
>>> +
>>> + desc_control = XDMA_DESC_CONTROL(XDMA_DESC_ADJACENT, 0);
>>> + for (i = 1; i < sw_desc->dblk_num; i++) {
>>> + block = &sw_desc->desc_blocks[i - 1];
>>> + desc = xdma_blk_last_desc(block);
>>> +
>>> + if (!(i & XDMA_DESC_BLOCK_MASK)) {
>>> + desc->control = cpu_to_le32(XDMA_DESC_CONTROL_LAST);
>>> + continue;
>>> + }
>>> + desc->control = cpu_to_le32(desc_control);
>>> + desc->next_desc = cpu_to_le64(block[1].dma_addr);
>>> + }
>>> +
>>> + /* update the last block */
>>> + last_blk_desc_num = sw_desc->desc_num & XDMA_DESC_ADJACENT_MASK;
>>> + if ((sw_desc->dblk_num & XDMA_DESC_BLOCK_MASK) > 1 &&
>>> + last_blk_desc_num) {
>>> + block = &sw_desc->desc_blocks[sw_desc->dblk_num - 2];
>>> + desc = xdma_blk_last_desc(block);
>>> + desc_control = XDMA_DESC_CONTROL(last_blk_desc_num, 0);
>>> + desc->control = cpu_to_le32(desc_control);
>>> + }
>>> +
>>> + block = &sw_desc->desc_blocks[sw_desc->dblk_num - 1];
>>> + desc = block->virt_addr + (last_blk_desc_num - 1) *
>>> XDMA_DESC_SIZE;
>>> + desc->control = cpu_to_le32(XDMA_DESC_CONTROL_LAST);
>>> +}
>>> +
>>> +static inline struct xdma_chan *to_xdma_chan(struct dma_chan *chan)
>>> +{
>>> + return container_of(chan, struct xdma_chan, vchan.chan);
>>> +}
>>> +
>>> +static inline struct xdma_desc *to_xdma_desc(struct virt_dma_desc
>>> *vdesc)
>>> +{
>>> + return container_of(vdesc, struct xdma_desc, vdesc);
>>> +}
>>> +
>>> +static int xdma_enable_intr(struct xdma_device *xdev)
>>> +{
>>> + int ret;
>>> +
>>> + ret = xdma_write_reg(xdev, XDMA_IRQ_BASE,
>>> XDMA_IRQ_CHAN_INT_EN_W1S, ~0);
>>> + if (ret)
>>> + xdma_err(xdev, "enable channel intr failed: %d", ret);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int xdma_disable_intr(struct xdma_device *xdev)
>>> +{
>>> + int ret;
>>> +
>>> + ret = xdma_write_reg(xdev, XDMA_IRQ_BASE,
>>> XDMA_IRQ_CHAN_INT_EN_W1C, ~0);
>>> + if (ret)
>>> + xdma_err(xdev, "disable channel intr failed: %d", ret);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +/**
>>> + * xdma_channel_init - Initialize DMA channel registers
>>> + * @chan: DMA channel pointer
>>> + */
>>> +static int xdma_channel_init(struct xdma_chan *chan)
>>> +{
>>> + struct xdma_device *xdev = chan->xdev_hdl;
>>> + int ret;
>>> +
>>> + ret = xdma_write_reg(xdev, chan->base, XDMA_CHAN_CONTROL_W1C,
>>> + CHAN_CTRL_NON_INCR_ADDR);
>>> + if (ret) {
>>> + xdma_err(xdev, "clear non incr addr failed: %d", ret);
>>> + return ret;
>>> + }
>>> +
>>> + ret = xdma_write_reg(xdev, chan->base, XDMA_CHAN_INTR_ENABLE,
>>> + CHAN_IM_ALL);
>>> + if (ret) {
>>> + xdma_err(xdev, "failed to set interrupt mask: %d", ret);
>>> + return ret;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * xdma_free_desc - Free descriptor
>>> + * @vdesc: Virtual DMA descriptor
>>> + */
>>> +static void xdma_free_desc(struct virt_dma_desc *vdesc)
>>> +{
>>> + struct xdma_desc *sw_desc;
>>> + int i;
>>> +
>>> + sw_desc = to_xdma_desc(vdesc);
>>> + for (i = 0; i < sw_desc->dblk_num; i++) {
>>> + if (!sw_desc->desc_blocks[i].virt_addr)
>>> + break;
>>> + dma_pool_free(sw_desc->chan->desc_pool,
>>> + sw_desc->desc_blocks[i].virt_addr,
>>> + sw_desc->desc_blocks[i].dma_addr);
>>> + }
>>> + kfree(sw_desc->desc_blocks);
>>> + kfree(sw_desc);
>>> +}
>>> +
>>> +/**
>>> + * xdma_alloc_desc - Allocate descriptor
>>> + * @chan: DMA channel pointer
>>> + * @desc_num: Number of hardware descriptors
>>> + */
>>> +static struct xdma_desc *
>>> +xdma_alloc_desc(struct xdma_chan *chan, u32 desc_num)
>>> +{
>>> + struct xdma_desc *sw_desc;
>>> + struct xdma_hw_desc *desc;
>>> + dma_addr_t dma_addr;
>>> + u32 dblk_num;
>>> + void *addr;
>>> + int i, j;
>>> +
>>> + sw_desc = kzalloc(sizeof(*sw_desc), GFP_NOWAIT);
>>> + if (!sw_desc)
>>> + return NULL;
>>> +
>>> + sw_desc->chan = chan;
>>> + sw_desc->desc_num = desc_num;
>>> + dblk_num = DIV_ROUND_UP(desc_num, XDMA_DESC_ADJACENT);
>>> + sw_desc->desc_blocks = kcalloc(dblk_num,
>>> sizeof(*sw_desc->desc_blocks),
>>> + GFP_NOWAIT);
>>> + if (!sw_desc->desc_blocks)
>>> + goto failed;
>>> +
>>> + sw_desc->dblk_num = dblk_num;
>>> + for (i = 0; i < sw_desc->dblk_num; i++) {
>>> + addr = dma_pool_alloc(chan->desc_pool, GFP_NOWAIT, &dma_addr);
>>> + if (!addr)
>>> + goto failed;
>>> +
>>> + sw_desc->desc_blocks[i].virt_addr = addr;
>>> + sw_desc->desc_blocks[i].dma_addr = dma_addr;
>>> + for (j = 0, desc = addr; j < XDMA_DESC_ADJACENT; j++)
>>> + desc[j].control = cpu_to_le32(XDMA_DESC_CONTROL(1, 0));
>>> + }
>>> +
>>> + xdma_link_desc_blocks(sw_desc);
>>> +
>>> + return sw_desc;
>>> +
>>> +failed:
>>> + xdma_free_desc(&sw_desc->vdesc);
>>> + return NULL;
>>> +}
>>> +
>>> +/**
>>> + * xdma_xfer_start - Start DMA transfer
>>> + * @xdma_chan: DMA channel pointer
>>> + */
>>> +static int xdma_xfer_start(struct xdma_chan *xdma_chan)
>>> +{
>>> + struct virt_dma_desc *vd = vchan_next_desc(&xdma_chan->vchan);
>>> + struct xdma_device *xdev = xdma_chan->xdev_hdl;
>>> + struct xdma_desc_block *block;
>>> + u32 val, completed_blocks;
>>> + struct xdma_desc *desc;
>>> + int ret;
>>> +
>>> + /*
>>> + * check if there is not any submitted descriptor or channel is
>>> busy.
>>> + * vchan lock should be held where this function is called.
>>> + */
>>> + if (!vd || xdma_chan->busy)
>>> + return -EINVAL;
>>> +
>>> + /* clear run stop bit to get ready for transfer */
>>> + ret = xdma_write_reg(xdev, xdma_chan->base, XDMA_CHAN_CONTROL_W1C,
>>> + CHAN_CTRL_RUN_STOP);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev, "write control failed: %d", ret);
>>> + return ret;
>>> + }
>>> +
>>> + desc = to_xdma_desc(vd);
>>> + if (desc->dir != xdma_chan->dir) {
>>> + dev_err(&xdev->pdev->dev, "incorrect request direction");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + /* set DMA engine to the first descriptor block */
>>> + completed_blocks = desc->completed_desc_num / XDMA_DESC_ADJACENT;
>>> + block = &desc->desc_blocks[completed_blocks];
>>> + val = FIELD_GET(XDMA_LO_ADDR_MASK, block->dma_addr);
>>> + ret = xdma_write_reg(xdev, XDMA_SGDMA_BASE(xdma_chan->base),
>>> + XDMA_SGDMA_DESC_LO, val);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev, "write hi addr failed: %d", ret);
>>> + return ret;
>>> + }
>>> +
>>> + val = FIELD_GET(XDMA_HI_ADDR_MASK, block->dma_addr);
>>> + ret = xdma_write_reg(xdev, XDMA_SGDMA_BASE(xdma_chan->base),
>>> + XDMA_SGDMA_DESC_HI, val);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev, "write lo addr failed: %d", ret);
>>> + return ret;
>>> + }
>>> +
>>> + if (completed_blocks + 1 == desc->dblk_num)
>>> + val = (desc->desc_num - 1) & XDMA_DESC_ADJACENT_MASK;
>>> + else
>>> + val = XDMA_DESC_ADJACENT - 1;
>>> + ret = xdma_write_reg(xdev, XDMA_SGDMA_BASE(xdma_chan->base),
>>> + XDMA_SGDMA_DESC_ADJ, val);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev, "write adjacent failed: %d", ret);
>>> + return ret;
>>> + }
>>> +
>>> + /* kick off DMA transfer */
>>> + ret = xdma_write_reg(xdev, xdma_chan->base, XDMA_CHAN_CONTROL,
>>> + CHAN_CTRL_START);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev, "write control failed: %d", ret);
>>> + return ret;
>>> + }
>>> +
>>> + xdma_chan->busy = true;
>>> + return 0;
>>> +}
>>> +
>>> +static void xdma_channel_tasklet(struct tasklet_struct *t)
>>> +{
>>> + struct xdma_chan *xdma_chan = from_tasklet(xdma_chan, t, tasklet);
>>> +
>>> + spin_lock(&xdma_chan->vchan.lock);
>>> + xdma_xfer_start(xdma_chan);
>>> + spin_unlock(&xdma_chan->vchan.lock);
>>> +}
>>> +
>>> +/**
>>> + * xdma_config_channels - Detect and config DMA channels
>>> + * @xdev: DMA device pointer
>>> + * @dir: Channel direction
>>> + */
>>> +static int xdma_config_channels(struct xdma_device *xdev,
>>> + enum dma_transfer_direction dir)
>>> +{
>>> + struct xdma_platdata *pdata = dev_get_platdata(&xdev->pdev->dev);
>>> + u32 base, identifier, target;
>>> + struct xdma_chan **chans;
>>> + u32 *chan_num;
>>> + int i, j, ret;
>>> +
>>> + if (dir == DMA_MEM_TO_DEV) {
>>> + base = XDMA_CHAN_H2C_OFFSET;
>>> + target = XDMA_CHAN_H2C_TARGET;
>>> + chans = &xdev->h2c_chans;
>>> + chan_num = &xdev->h2c_chan_num;
>>> + } else if (dir == DMA_DEV_TO_MEM) {
>>> + base = XDMA_CHAN_C2H_OFFSET;
>>> + target = XDMA_CHAN_C2H_TARGET;
>>> + chans = &xdev->c2h_chans;
>>> + chan_num = &xdev->c2h_chan_num;
>>> + } else {
>>> + dev_err(&xdev->pdev->dev, "invalid direction specified");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + /* detect number of available DMA channels */
>>> + for (i = 0, *chan_num = 0; i < pdata->max_dma_channels; i++) {
>>> + ret = xdma_read_reg(xdev, base + i * XDMA_CHAN_STRIDE,
>>> + XDMA_CHAN_IDENTIFIER, &identifier);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev,
>>> + "failed to read channel id: %d", ret);
>>> + return ret;
>>> + }
>>> +
>>> + /* check if it is available DMA channel */
>>> + if (XDMA_CHAN_CHECK_TARGET(identifier, target))
>>> + (*chan_num)++;
>>> + }
>>> +
>>> + if (!*chan_num) {
>>> + dev_err(&xdev->pdev->dev, "does not probe any channel");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + *chans = devm_kzalloc(&xdev->pdev->dev, sizeof(**chans) *
>>> (*chan_num),
>>> + GFP_KERNEL);
>>> + if (!*chans)
>>> + return -ENOMEM;
>>> +
>>> + for (i = 0, j = 0; i < pdata->max_dma_channels; i++) {
>>> + ret = xdma_read_reg(xdev, base + i * XDMA_CHAN_STRIDE,
>>> + XDMA_CHAN_IDENTIFIER, &identifier);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev,
>>> + "failed to read channel id: %d", ret);
>>> + return ret;
>>> + }
>>> +
>>> + if (!XDMA_CHAN_CHECK_TARGET(identifier, target))
>>> + continue;
>>> +
>>> + if (j == *chan_num) {
>>> + dev_err(&xdev->pdev->dev, "invalid channel number");
>>> + return -EIO;
>>> + }
>>> +
>>> + /* init channel structure and hardware */
>>> + (*chans)[j].xdev_hdl = xdev;
>>> + (*chans)[j].base = base + i * XDMA_CHAN_STRIDE;
>>> + (*chans)[j].dir = dir;
>>> +
>>> + ret = xdma_channel_init(&(*chans)[j]);
>>> + if (ret)
>>> + return ret;
>>> + (*chans)[j].vchan.desc_free = xdma_free_desc;
>>> + vchan_init(&(*chans)[j].vchan, &xdev->dma_dev);
>>> +
>>> + j++;
>>> + }
>>> +
>>> + dev_info(&xdev->pdev->dev, "configured %d %s channels", j,
>>> + (dir == DMA_MEM_TO_DEV) ? "H2C" : "C2H");
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * xdma_issue_pending - Issue pending transactions
>>> + * @chan: DMA channel pointer
>>> + */
>>> +static void xdma_issue_pending(struct dma_chan *chan)
>>> +{
>>> + struct xdma_chan *xdma_chan = to_xdma_chan(chan);
>>> + unsigned long flags;
>>> +
>>> + spin_lock_irqsave(&xdma_chan->vchan.lock, flags);
>>> + if (vchan_issue_pending(&xdma_chan->vchan))
>>> + xdma_xfer_start(xdma_chan);
>>> + spin_unlock_irqrestore(&xdma_chan->vchan.lock, flags);
>>> +}
>>> +
>>> +/**
>>> + * xdma_prep_device_sg - prepare a descriptor for a
>>> + * DMA transaction
>>> + * @chan: DMA channel pointer
>>> + * @sgl: Transfer scatter gather list
>>> + * @sg_len: Length of scatter gather list
>>> + * @dir: Transfer direction
>>> + * @flags: transfer ack flags
>>> + * @context: APP words of the descriptor
>>> + */
>>> +static struct dma_async_tx_descriptor *
>>> +xdma_prep_device_sg(struct dma_chan *chan, struct scatterlist *sgl,
>>> + unsigned int sg_len, enum dma_transfer_direction dir,
>>> + unsigned long flags, void *context)
>>> +{
>>> + struct xdma_chan *xdma_chan = to_xdma_chan(chan);
>>> + struct dma_async_tx_descriptor *tx_desc;
>>> + u32 desc_num = 0, i, len, rest;
>>> + struct xdma_desc_block *dblk;
>>> + struct xdma_desc *sw_desc;
>>> + struct scatterlist *sg;
>>> + dma_addr_t addr;
>>> + u64 dev_addr, *src, *dst;
>>> + struct xdma_hw_desc *desc;
>>> +
>>> + for_each_sg(sgl, sg, sg_len, i)
>>> + desc_num += DIV_ROUND_UP(sg_dma_len(sg), XDMA_DESC_BLEN_MAX);
>>> +
>>> + sw_desc = xdma_alloc_desc(xdma_chan, desc_num);
>>> + if (!sw_desc)
>>> + return NULL;
>>> + sw_desc->dir = dir;
>>> +
>>> + if (dir == DMA_MEM_TO_DEV) {
>>> + dev_addr = xdma_chan->cfg.dst_addr;
>>> + src = &addr;
>>> + dst = &dev_addr;
>>> + } else {
>>> + dev_addr = xdma_chan->cfg.src_addr;
>>> + src = &dev_addr;
>>> + dst = &addr;
>>> + }
>>> +
>>> + dblk = sw_desc->desc_blocks;
>>> + desc = dblk->virt_addr;
>>> + desc_num = 1;
>>> + for_each_sg(sgl, sg, sg_len, i) {
>>> + addr = sg_dma_address(sg);
>>> + rest = sg_dma_len(sg);
>>> +
>>> + do {
>>> + len = min_t(u32, rest, XDMA_DESC_BLEN_MAX);
>>> + /* set hardware descriptor */
>>> + desc->bytes = cpu_to_le32(len);
>>> + desc->src_addr = cpu_to_le64(*src);
>>> + desc->dst_addr = cpu_to_le64(*dst);
>>> +
>>> + if (!(desc_num & XDMA_DESC_ADJACENT_MASK)) {
>>> + dblk++;
>>> + desc = dblk->virt_addr;
>>> + } else {
>>> + desc++;
>>> + }
>>> +
>>> + desc_num++;
>>> + dev_addr += len;
>>> + addr += len;
>>> + rest -= len;
>>> + } while (rest);
>>> + }
>>> +
>>> + tx_desc = vchan_tx_prep(&xdma_chan->vchan, &sw_desc->vdesc,
>>> flags);
>>> + if (!tx_desc)
>>> + goto failed;
>>> +
>>> + return tx_desc;
>>> +
>>> +failed:
>>> + xdma_free_desc(&sw_desc->vdesc);
>>> +
>>> + return NULL;
>>> +}
>>> +
>>> +/**
>>> + * xdma_device_config - Configure the DMA channel
>>> + * @chan: DMA channel
>>> + * @cfg: channel configuration
>>> + */
>>> +static int xdma_device_config(struct dma_chan *chan,
>>> + struct dma_slave_config *cfg)
>>> +{
>>> + struct xdma_chan *xdma_chan = to_xdma_chan(chan);
>>> +
>>> + memcpy(&xdma_chan->cfg, cfg, sizeof(*cfg));
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * xdma_free_chan_resources - Free channel resources
>>> + * @chan: DMA channel
>>> + */
>>> +static void xdma_free_chan_resources(struct dma_chan *chan)
>>> +{
>>> + struct xdma_chan *xdma_chan = to_xdma_chan(chan);
>>> +
>>> + vchan_free_chan_resources(&xdma_chan->vchan);
>>> + dma_pool_destroy(xdma_chan->desc_pool);
>>> + xdma_chan->desc_pool = NULL;
>>> +}
>>> +
>>> +/**
>>> + * xdma_alloc_chan_resources - Allocate channel resources
>>> + * @chan: DMA channel
>>> + */
>>> +static int xdma_alloc_chan_resources(struct dma_chan *chan)
>>> +{
>>> + struct xdma_chan *xdma_chan = to_xdma_chan(chan);
>>> + struct xdma_device *xdev = xdma_chan->xdev_hdl;
>>> +
>>> + xdma_chan->desc_pool = dma_pool_create(dma_chan_name(chan),
>>> + xdev->dma_dev.dev,
>>> + XDMA_DESC_BLOCK_SIZE,
>>> + XDMA_DESC_BLOCK_ALIGN,
>>> + 0);
>>> + if (!xdma_chan->desc_pool) {
>>> + dev_err(&chan->dev->device,
>>> + "unable to allocate descriptor pool");
>>> + return -ENOMEM;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * xdma_channel_isr - XDMA channel interrupt handler
>>> + * @irq: IRQ number
>>> + * @dev_id: Pointer to the DMA channel structure
>>> + */
>>> +static irqreturn_t xdma_channel_isr(int irq, void *dev_id)
>>> +{
>>> + struct xdma_chan *xdma_chan = dev_id;
>>> + u32 complete_desc_num = 0;
>>> + struct virt_dma_desc *vd;
>>> + struct xdma_desc *desc;
>>> + int ret;
>>> +
>>> + spin_lock(&xdma_chan->vchan.lock);
>>> +
>>> + /* get submitted request */
>>> + vd = vchan_next_desc(&xdma_chan->vchan);
>>> + if (!vd)
>>> + goto out;
>>> +
>>> + xdma_chan->busy = false;
>>> + desc = to_xdma_desc(vd);
>>> +
>>> + ret = xdma_read_reg(xdma_chan->xdev_hdl, xdma_chan->base,
>>> + XDMA_CHAN_COMPLETED_DESC, &complete_desc_num);
>>> + if (ret)
>>> + goto out;
>>> +
>>> + desc->completed_desc_num += complete_desc_num;
>>> + /*
>>> + * if all data blocks are transferred, remove and complete the
>>> request
>>> + */
>>> + if (desc->completed_desc_num == desc->desc_num) {
>>> + list_del(&vd->node);
>>> + vchan_cookie_complete(vd);
>>> + goto out;
>>> + }
>>> +
>>> + if (desc->completed_desc_num > desc->desc_num ||
>>> + complete_desc_num != XDMA_DESC_BLOCK_NUM * XDMA_DESC_ADJACENT)
>>> + goto out;
>>> +
>>> + /* transfer the rest of data */
>>> + tasklet_schedule(&xdma_chan->tasklet);
>>
>> There's an effort upstream to deprecate the usage tasklets [1]. Any
>> thought on using threaded irq instead especially with a new driver?
>>
>> [1]: https://lwn.net/Articles/830964/
>>
>> DJ
>
> Thanks a lot for pointing this out. In this V2 patch series, we have
> moved most of code from tasklet handler to prep_* (only few register
> accesses left). Because the handler is pretty short and quick now, I
> will remove the tasklet and call xdma_xfer_start() from interrupt
> handler directly.
That works too.
>
>
> Thanks,
>
> Lizhi
>
>>
>>> +
>>> +out:
>>> + spin_unlock(&xdma_chan->vchan.lock);
>>> + return IRQ_HANDLED;
>>> +}
>>> +
>>> +/**
>>> + * xdma_irq_fini - Uninitialize IRQ
>>> + * @xdev: DMA device pointer
>>> + */
>>> +static void xdma_irq_fini(struct xdma_device *xdev)
>>> +{
>>> + int ret, i;
>>> +
>>> + /* disable interrupt */
>>> + ret = xdma_disable_intr(xdev);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev, "failed to disable interrupts: %d",
>>> + ret);
>>> + }
>>> +
>>> + /* free irq handler */
>>> + for (i = 0; i < xdev->h2c_chan_num; i++) {
>>> + free_irq(xdev->h2c_chans[i].irq, &xdev->h2c_chans[i]);
>>> + tasklet_kill(&xdev->h2c_chans[i].tasklet);
>>> + }
>>> + for (i = 0; i < xdev->c2h_chan_num; i++) {
>>> + free_irq(xdev->c2h_chans[i].irq, &xdev->c2h_chans[i]);
>>> + tasklet_kill(&xdev->c2h_chans[i].tasklet);
>>> + }
>>> +}
>>> +
>>> +/**
>>> + * xdma_set_vector_reg - configure hardware IRQ registers
>>> + * @xdev: DMA device pointer
>>> + * @vec_tbl_start: Start of IRQ registers
>>> + * @irq_start: Start of IRQ
>>> + * @irq_num: Number of IRQ
>>> + */
>>> +static int xdma_set_vector_reg(struct xdma_device *xdev, u32
>>> vec_tbl_start,
>>> + u32 irq_start, u32 irq_num)
>>> +{
>>> + u32 shift, i, val = 0;
>>> + int ret;
>>> +
>>> + /* Each IRQ register is 32 bit and contains 4 IRQs */
>>> + while (irq_num > 0) {
>>> + for (i = 0; i < 4; i++) {
>>> + shift = XDMA_IRQ_VEC_SHIFT * i;
>>> + val |= irq_start << shift;
>>> + irq_start++;
>>> + irq_num--;
>>> + }
>>> +
>>> + /* write IRQ register */
>>> + ret = xdma_write_reg(xdev, XDMA_IRQ_BASE, vec_tbl_start, val);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev, "failed to set vector: %d",
>>> + ret);
>>> + return ret;
>>> + }
>>> + vec_tbl_start += sizeof(u32);
>>> + val = 0;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * xdma_irq_init - initialize IRQs
>>> + * @xdev: DMA device pointer
>>> + */
>>> +static int xdma_irq_init(struct xdma_device *xdev)
>>> +{
>>> + u32 irq = xdev->irq_start;
>>> + int i, j, ret;
>>> +
>>> + /* return failure if there are not enough IRQs */
>>> + if (xdev->irq_num < xdev->h2c_chan_num + xdev->c2h_chan_num) {
>>> + dev_err(&xdev->pdev->dev, "not enough irq");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + /* setup H2C interrupt handler */
>>> + for (i = 0; i < xdev->h2c_chan_num; i++) {
>>> + ret = request_irq(irq, xdma_channel_isr, 0,
>>> + "xdma-h2c-channel", &xdev->h2c_chans[i]);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev,
>>> + "H2C channel%d request irq%d failed: %d",
>>> + i, irq, ret);
>>> + for (j = 0; j < i; j++) {
>>> + free_irq(xdev->h2c_chans[j].irq,
>>> + &xdev->h2c_chans[j]);
>>> + }
>>> + return ret;
>>> + }
>>> + xdev->h2c_chans[i].irq = irq;
>>> + tasklet_setup(&xdev->h2c_chans[i].tasklet,
>>> + xdma_channel_tasklet);
>>> + irq++;
>>> + }
>>> +
>>> + /* setup C2H interrupt handler */
>>> + for (i = 0; i < xdev->c2h_chan_num; i++) {
>>> + ret = request_irq(irq, xdma_channel_isr, 0,
>>> + "xdma-c2h-channel", &xdev->c2h_chans[i]);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev,
>>> + "H2C channel%d request irq%d failed: %d",
>>> + i, irq, ret);
>>> + for (j = 0; j < i; j++) {
>>> + free_irq(xdev->c2h_chans[j].irq,
>>> + &xdev->c2h_chans[j]);
>>> + }
>>> + goto failed_init_c2h;
>>> + }
>>> + xdev->c2h_chans[i].irq = irq;
>>> + tasklet_setup(&xdev->c2h_chans[i].tasklet,
>>> + xdma_channel_tasklet);
>>> + irq++;
>>> + }
>>> +
>>> + /* config hardware IRQ registers */
>>> + ret = xdma_set_vector_reg(xdev, XDMA_IRQ_CHAN_VEC_NUM, 0,
>>> + xdev->h2c_chan_num + xdev->c2h_chan_num);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev, "failed to set channel vectors: %d",
>>> + ret);
>>> + goto failed;
>>> + }
>>> +
>>> + /* enable interrupt */
>>> + ret = xdma_enable_intr(xdev);
>>> + if (ret) {
>>> + dev_err(&xdev->pdev->dev, "failed to enable interrupts: %d",
>>> + ret);
>>> + goto failed;
>>> + }
>>> +
>>> + return 0;
>>> +
>>> +failed:
>>> + for (i = 0; i < xdev->c2h_chan_num; i++)
>>> + free_irq(xdev->c2h_chans[i].irq, &xdev->c2h_chans[i]);
>>> +failed_init_c2h:
>>> + for (i = 0; i < xdev->h2c_chan_num; i++)
>>> + free_irq(xdev->h2c_chans[i].irq, &xdev->h2c_chans[i]);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static bool xdma_filter_fn(struct dma_chan *chan, void *param)
>>> +{
>>> + struct xdma_chan *xdma_chan = to_xdma_chan(chan);
>>> + struct xdma_chan_info *chan_info = param;
>>> +
>>> + if (chan_info->dir != xdma_chan->dir)
>>> + return false;
>>> +
>>> + return true;
>>> +}
>>> +
>>> +/**
>>> + * xdma_remove - Driver remove function
>>> + * @pdev: Pointer to the platform_device structure
>>> + */
>>> +static int xdma_remove(struct platform_device *pdev)
>>> +{
>>> + struct xdma_device *xdev = platform_get_drvdata(pdev);
>>> +
>>> + if (xdev->status & XDMA_DEV_STATUS_INIT_MSIX)
>>> + xdma_irq_fini(xdev);
>>> +
>>> + if (xdev->status & XDMA_DEV_STATUS_REG_DMA)
>>> + dma_async_device_unregister(&xdev->dma_dev);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * xdma_probe - Driver probe function
>>> + * @pdev: Pointer to the platform_device structure
>>> + */
>>> +static int xdma_probe(struct platform_device *pdev)
>>> +{
>>> + struct xdma_platdata *pdata = dev_get_platdata(&pdev->dev);
>>> + struct xdma_device *xdev;
>>> + void __iomem *reg_base;
>>> + struct resource *res;
>>> + int ret = -ENODEV;
>>> +
>>> + if (pdata->max_dma_channels > XDMA_MAX_CHANNELS) {
>>> + dev_err(&pdev->dev, "invalid max dma channels %d",
>>> + pdata->max_dma_channels);
>>> + return -EINVAL;
>>> + }
>>> +
>>> + xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL);
>>> + if (!xdev)
>>> + return -ENOMEM;
>>> +
>>> + platform_set_drvdata(pdev, xdev);
>>> + xdev->pdev = pdev;
>>> +
>>> + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
>>> + if (!res) {
>>> + dev_err(&pdev->dev, "failed to get irq resource");
>>> + goto failed;
>>> + }
>>> + xdev->irq_start = res->start;
>>> + xdev->irq_num = res->end - res->start + 1;
>>> +
>>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> + if (!res) {
>>> + dev_err(&pdev->dev, "failed to get io resource");
>>> + goto failed;
>>> + }
>>> +
>>> + reg_base = devm_ioremap_resource(&pdev->dev, res);
>>> + if (!reg_base) {
>>> + dev_err(&pdev->dev, "ioremap failed");
>>> + goto failed;
>>> + }
>>> +
>>> + xdev->regmap = devm_regmap_init_mmio(&pdev->dev, reg_base,
>>> + &xdma_regmap_config);
>>> + if (!xdev->regmap) {
>>> + dev_err(&pdev->dev, "config regmap failed: %d", ret);
>>> + goto failed;
>>> + }
>>> + INIT_LIST_HEAD(&xdev->dma_dev.channels);
>>> +
>>> + ret = xdma_config_channels(xdev, DMA_MEM_TO_DEV);
>>> + if (ret) {
>>> + dev_err(&pdev->dev, "config H2C channels failed: %d", ret);
>>> + goto failed;
>>> + }
>>> +
>>> + ret = xdma_config_channels(xdev, DMA_DEV_TO_MEM);
>>> + if (ret) {
>>> + dev_err(&pdev->dev, "config C2H channels failed: %d", ret);
>>> + goto failed;
>>> + }
>>> +
>>> + dma_cap_set(DMA_SLAVE, xdev->dma_dev.cap_mask);
>>> + dma_cap_set(DMA_PRIVATE, xdev->dma_dev.cap_mask);
>>> +
>>> + xdev->dma_dev.dev = &pdev->dev;
>>> + xdev->dma_dev.device_free_chan_resources =
>>> xdma_free_chan_resources;
>>> + xdev->dma_dev.device_alloc_chan_resources =
>>> xdma_alloc_chan_resources;
>>> + xdev->dma_dev.device_tx_status = dma_cookie_status;
>>> + xdev->dma_dev.device_prep_slave_sg = xdma_prep_device_sg;
>>> + xdev->dma_dev.device_config = xdma_device_config;
>>> + xdev->dma_dev.device_issue_pending = xdma_issue_pending;
>>> + xdev->dma_dev.filter.map = pdata->device_map;
>>> + xdev->dma_dev.filter.mapcnt = pdata->device_map_cnt;
>>> + xdev->dma_dev.filter.fn = xdma_filter_fn;
>>> +
>>> + ret = dma_async_device_register(&xdev->dma_dev);
>>> + if (ret) {
>>> + dev_err(&pdev->dev, "failed to register Xilinx XDMA: %d",
>>> ret);
>>> + goto failed;
>>> + }
>>> + xdev->status |= XDMA_DEV_STATUS_REG_DMA;
>>> +
>>> + ret = xdma_irq_init(xdev);
>>> + if (ret) {
>>> + dev_err(&pdev->dev, "failed to init msix: %d", ret);
>>> + goto failed;
>>> + }
>>> + xdev->status |= XDMA_DEV_STATUS_INIT_MSIX;
>>> +
>>> + return 0;
>>> +
>>> +failed:
>>> + xdma_remove(pdev);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static const struct platform_device_id xdma_id_table[] = {
>>> + { "xdma", 0},
>>> + { },
>>> +};
>>> +
>>> +static struct platform_driver xdma_driver = {
>>> + .driver = {
>>> + .name = "xdma",
>>> + },
>>> + .id_table = xdma_id_table,
>>> + .probe = xdma_probe,
>>> + .remove = xdma_remove,
>>> +};
>>> +
>>> +module_platform_driver(xdma_driver);
>>> +
>>> +MODULE_DESCRIPTION("AMD XDMA driver");
>>> +MODULE_AUTHOR("XRT Team <runtime@...inx.com>");
>>> +MODULE_LICENSE("GPL");
>>> diff --git a/include/linux/platform_data/amd_xdma.h
>>> b/include/linux/platform_data/amd_xdma.h
>>> new file mode 100644
>>> index 000000000000..04bcfc74ab36
>>> --- /dev/null
>>> +++ b/include/linux/platform_data/amd_xdma.h
>>> @@ -0,0 +1,34 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-or-later */
>>> +/*
>>> + * Copyright (C) 2022 Advanced Micro Devices, Inc. All rights
>>> reserved.
>>> + */
>>> +
>>> +#ifndef _PLATDATA_AMD_XDMA_H
>>> +#define _PLATDATA_AMD_XDMA_H
>>> +
>>> +#include <linux/dmaengine.h>
>>> +
>>> +/**
>>> + * struct xdma_chan_info - DMA channel information
>>> + * This information is used to match channel when request dma
>>> channel
>>> + * @dir: Channel transfer direction
>>> + */
>>> +struct xdma_chan_info {
>>> + enum dma_transfer_direction dir;
>>> +};
>>> +
>>> +#define XDMA_FILTER_PARAM(chan_info) ((void *)(chan_info))
>>> +
>>> +struct dma_slave_map;
>>> +
>>> +/**
>>> + * struct xdma_platdata - platform specific data for XDMA engine
>>> + * @max_dma_channels: Maximum dma channels in each direction
>>> + */
>>> +struct xdma_platdata {
>>> + u32 max_dma_channels;
>>> + u32 device_map_cnt;
>>> + struct dma_slave_map *device_map;
>>> +};
>>> +
>>> +#endif /* _PLATDATA_AMD_XDMA_H */
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