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Date: Fri, 4 Nov 2022 09:57:38 -0700
From: Lizhi Hou <lizhi.hou@....com>
To: Vinod Koul <vkoul@...nel.org>
CC: <dmaengine@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<trix@...hat.com>, <tumic@...see.org>, <max.zhen@....com>,
<sonal.santan@....com>, <larry.liu@....com>, <brian.xu@....com>
Subject: Re: [PATCH V9 XDMA 1/2] dmaengine: xilinx: xdma: Add xilinx xdma
driver
On 11/4/22 07:32, Vinod Koul wrote:
> On 25-10-22, 10:57, 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 | 14 +
>> drivers/dma/xilinx/Makefile | 1 +
>> drivers/dma/xilinx/xdma-regs.h | 171 +++++
>> drivers/dma/xilinx/xdma.c | 954 +++++++++++++++++++++++++
>> include/linux/platform_data/amd_xdma.h | 34 +
>> 6 files changed, 1184 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 e68a0804394d..d598c4e23901 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -22575,6 +22575,16 @@ 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 7524b62a8870..bb5b542c2f9a 100644
>> --- a/drivers/dma/Kconfig
>> +++ b/drivers/dma/Kconfig
>> @@ -753,6 +753,20 @@ 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"
>> + depends on HAS_IOMEM
>> + 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..bb8b38669d8d
>> --- /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.
>> + */
>> +
>> +#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 32
>> +#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))
> We have macros do that, please drop the xxx_SHIFT defines and use
> FIELD_GET/PREP to extract/set bits
Ok, I will use the macros.
>
>> +#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 GENMASK(13, 9)
>> +#define CHAN_CTRL_IE_DESC_ERROR GENMASK(23, 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 GENMASK(13, 9)
>> +#define XDMA_CTRL_IE_DESC_ERROR GENMASK(23, 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..85ba306c457e
>> --- /dev/null
>> +++ b/drivers/dma/xilinx/xdma.c
>> @@ -0,0 +1,954 @@
>> +// 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.
>> + */
>> +
>> +/*
>> + * 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 <linux/pci.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
>> + */
>> +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 xdma_desc - DMA desc structure
>> + * @vdesc: Virtual DMA descriptor
>> + * @chan: DMA channel pointer
>> + * @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)
>> +#define XDMA_CHAN_NUM(_xd) ({ \
>> + typeof(_xd) (xd) = (_xd); \
>> + ((xd)->h2c_chan_num + (xd)->c2h_chan_num); })
>> +
>> +/* 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);
>> +}
> Do you really need one more level indirection?
Do you mean using readl / writel instead of regmap_* here?
>
>> +
>> +/* 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 - 1) & XDMA_DESC_ADJACENT_MASK) + 1;
> single line should do here, can you drop the outer brace
Ok.
>
>
>> + if (((sw_desc->dblk_num - 1) & XDMA_DESC_BLOCK_MASK) > 0) {
>> + 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);
> why not move err into xdma_write_reg(), rather than adding in each
> helper!
Ok.
>
>
>> +
>> + 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);
> who will free sw_desc here?
sw_desc is freed by xdma_free_desc(). xdma_free_desc() is virt-dma
callback it converts struct virt_dma_desc pointer to driver sw_desc
pointer and free the whole thing.
>
>> + 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) {
>> + xdma_err(xdev, "write control failed: %d", ret);
>> + return ret;
>> + }
>> +
>> + desc = to_xdma_desc(vd);
>> + if (desc->dir != xdma_chan->dir) {
>> + xdma_err(xdev, "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) {
>> + xdma_err(xdev, "write hi addr failed: %d", ret);
>> + return ret;
>> + }
>> +
>> + val = FIELD_GET(XDMA_HI_ADDR_MASK, (u64)block->dma_addr);
>> + ret = xdma_write_reg(xdev, XDMA_SGDMA_BASE(xdma_chan->base),
>> + XDMA_SGDMA_DESC_HI, val);
>> + if (ret) {
>> + xdma_err(xdev, "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) {
>> + xdma_err(xdev, "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) {
>> + xdma_err(xdev, "write control failed: %d", ret);
>> + return ret;
>> + }
>> +
>> + xdma_chan->busy = true;
>> + return 0;
>> +}
>> +
>> +/**
>> + * 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)
> pls align to preceeding line open brace... checkpatch --strict would
> warn you about style inconsistencies
This is due to "+ " added in front. The code is aligned after applying
the patch.
checkpatch -strict is passed before I submitted my patches.
>
>> +{
>> + 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 {
>> + xdma_err(xdev, "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) {
>> + xdma_err(xdev, "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) {
>> + xdma_err(xdev, "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) {
>> + xdma_err(xdev, "failed to read channel id: %d", ret);
>> + return ret;
>> + }
>> +
>> + if (!XDMA_CHAN_CHECK_TARGET(identifier, target))
>> + continue;
>> +
>> + if (j == *chan_num) {
>> + xdma_err(xdev, "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_hw_desc *desc;
>> + struct xdma_desc *sw_desc;
>> + u64 dev_addr, *src, *dst;
>> + struct scatterlist *sg;
>> + u64 addr;
>> +
>> + 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;
>> + struct device *dev = xdev->dma_dev.dev;
>> +
>> + while (dev && !dev_is_pci(dev))
>> + dev = dev->parent;
>> + if (!dev) {
>> + xdma_err(xdev, "unable to find pci device");
>> + return -EINVAL;
>> + }
>> +
>> + xdma_chan->desc_pool = dma_pool_create(dma_chan_name(chan),
>> + dev, XDMA_DESC_BLOCK_SIZE,
>> + XDMA_DESC_BLOCK_ALIGN, 0);
>> + if (!xdma_chan->desc_pool) {
>> + xdma_err(xdev, "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 */
>> + xdma_xfer_start(xdma_chan);
>> +
>> +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)
>> + xdma_err(xdev, "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]);
>> +
>> + for (i = 0; i < xdev->c2h_chan_num; i++)
>> + free_irq(xdev->c2h_chans[i].irq, &xdev->c2h_chans[i]);
>> +}
>> +
>> +/**
>> + * 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) {
>> + xdma_err(xdev, "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 < XDMA_CHAN_NUM(xdev)) {
>> + xdma_err(xdev, "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) {
>> + xdma_err(xdev, "H2C channel%d request irq%d failed: %d",
>> + i, irq, ret);
>> + goto failed_init_h2c;
>> + }
>> + xdev->h2c_chans[i].irq = irq;
>> + irq++;
>> + }
>> +
>> + /* setup C2H interrupt handler */
>> + for (j = 0; j < xdev->c2h_chan_num; j++) {
>> + ret = request_irq(irq, xdma_channel_isr, 0,
>> + "xdma-c2h-channel", &xdev->c2h_chans[j]);
>> + if (ret) {
>> + xdma_err(xdev, "H2C channel%d request irq%d failed: %d",
>> + j, irq, ret);
>> + goto failed_init_c2h;
>> + }
>> + xdev->c2h_chans[j].irq = irq;
>> + irq++;
>> + }
>> +
>> + /* config hardware IRQ registers */
>> + ret = xdma_set_vector_reg(xdev, XDMA_IRQ_CHAN_VEC_NUM, 0,
>> + XDMA_CHAN_NUM(xdev));
>> + if (ret) {
>> + xdma_err(xdev, "failed to set channel vectors: %d", ret);
>> + goto failed_init_c2h;
>> + }
>> +
>> + /* enable interrupt */
>> + ret = xdma_enable_intr(xdev);
>> + if (ret) {
>> + xdma_err(xdev, "failed to enable interrupts: %d", ret);
>> + goto failed_init_c2h;
>> + }
>> +
>> + return 0;
>> +
>> +failed_init_c2h:
>> + while (j--)
>> + free_irq(xdev->c2h_chans[j].irq, &xdev->c2h_chans[j]);
>> +failed_init_h2c:
>> + while (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;
>> +
>> + return chan_info->dir == xdma_chan->dir;
>> +}
>> +
>> +/**
>> + * 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) {
>> + xdma_err(xdev, "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) {
>> + xdma_err(xdev, "failed to get io resource");
>> + goto failed;
>> + }
>> +
>> + reg_base = devm_ioremap_resource(&pdev->dev, res);
>> + if (!reg_base) {
>> + xdma_err(xdev, "ioremap failed");
>> + goto failed;
>> + }
>> +
>> + xdev->regmap = devm_regmap_init_mmio(&pdev->dev, reg_base,
>> + &xdma_regmap_config);
>> + if (!xdev->regmap) {
>> + xdma_err(xdev, "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) {
>> + xdma_err(xdev, "config H2C channels failed: %d", ret);
>> + goto failed;
>> + }
>> +
>> + ret = xdma_config_channels(xdev, DMA_DEV_TO_MEM);
>> + if (ret) {
>> + xdma_err(xdev, "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) {
>> + xdma_err(xdev, "failed to register Xilinx XDMA: %d", ret);
>> + goto failed;
>> + }
>> + xdev->status |= XDMA_DEV_STATUS_REG_DMA;
>> +
>> + ret = xdma_irq_init(xdev);
>> + if (ret) {
>> + xdma_err(xdev, "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 <runtimeca39d@....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..b5e23e14bac8
>> --- /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.
>> + */
>> +
>> +#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;
>> +};
> why do you need this plat data
max_dma_channels is used to specify the maximum dma channels will be used.
device_map and device_map_cnt are used to define the dma channel names
which are used by dma_request_chan().
One of the existing example is: include/linux/platform_data/mmp_dma.h
Thanks,
Lizhi
>
>> +
>> +#endif /* _PLATDATA_AMD_XDMA_H */
>> --
>> 2.27.0
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