root/drivers/dma/hisi_dma.c
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2019-2022 HiSilicon Limited. */

#include <linux/bitfield.h>
#include <linux/dmaengine.h>
#include <linux/init.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/spinlock.h>
#include "virt-dma.h"

/* HiSilicon DMA register common field define */
#define HISI_DMA_Q_SQ_BASE_L                    0x0
#define HISI_DMA_Q_SQ_BASE_H                    0x4
#define HISI_DMA_Q_SQ_DEPTH                     0x8
#define HISI_DMA_Q_SQ_TAIL_PTR                  0xc
#define HISI_DMA_Q_CQ_BASE_L                    0x10
#define HISI_DMA_Q_CQ_BASE_H                    0x14
#define HISI_DMA_Q_CQ_DEPTH                     0x18
#define HISI_DMA_Q_CQ_HEAD_PTR                  0x1c
#define HISI_DMA_Q_CTRL0                        0x20
#define HISI_DMA_Q_CTRL0_QUEUE_EN               BIT(0)
#define HISI_DMA_Q_CTRL0_QUEUE_PAUSE            BIT(4)
#define HISI_DMA_Q_CTRL1                        0x24
#define HISI_DMA_Q_CTRL1_QUEUE_RESET            BIT(0)
#define HISI_DMA_Q_FSM_STS                      0x30
#define HISI_DMA_Q_FSM_STS_MASK                 GENMASK(3, 0)
#define HISI_DMA_Q_ERR_INT_NUM0                 0x84
#define HISI_DMA_Q_ERR_INT_NUM1                 0x88
#define HISI_DMA_Q_ERR_INT_NUM2                 0x8c

/* HiSilicon IP08 DMA register and field define */
#define HISI_DMA_HIP08_MODE                     0x217C
#define HISI_DMA_HIP08_Q_BASE                   0x0
#define HISI_DMA_HIP08_Q_CTRL0_ERR_ABORT_EN     BIT(2)
#define HISI_DMA_HIP08_Q_INT_STS                0x40
#define HISI_DMA_HIP08_Q_INT_MSK                0x44
#define HISI_DMA_HIP08_Q_INT_STS_MASK           GENMASK(14, 0)
#define HISI_DMA_HIP08_Q_ERR_INT_NUM3           0x90
#define HISI_DMA_HIP08_Q_ERR_INT_NUM4           0x94
#define HISI_DMA_HIP08_Q_ERR_INT_NUM5           0x98
#define HISI_DMA_HIP08_Q_ERR_INT_NUM6           0x48
#define HISI_DMA_HIP08_Q_CTRL0_SQCQ_DRCT        BIT(24)

/* HiSilicon IP09 DMA register and field define */
#define HISI_DMA_HIP09_DMA_FLR_DISABLE          0xA00
#define HISI_DMA_HIP09_DMA_FLR_DISABLE_B        BIT(0)
#define HISI_DMA_HIP09_Q_BASE                   0x2000
#define HISI_DMA_HIP09_Q_CTRL0_ERR_ABORT_EN     GENMASK(31, 28)
#define HISI_DMA_HIP09_Q_CTRL0_SQ_DRCT          BIT(26)
#define HISI_DMA_HIP09_Q_CTRL0_CQ_DRCT          BIT(27)
#define HISI_DMA_HIP09_Q_CTRL1_VA_ENABLE        BIT(2)
#define HISI_DMA_HIP09_Q_INT_STS                0x40
#define HISI_DMA_HIP09_Q_INT_MSK                0x44
#define HISI_DMA_HIP09_Q_INT_STS_MASK           0x1
#define HISI_DMA_HIP09_Q_ERR_INT_STS            0x48
#define HISI_DMA_HIP09_Q_ERR_INT_MSK            0x4C
#define HISI_DMA_HIP09_Q_ERR_INT_STS_MASK       GENMASK(18, 1)
#define HISI_DMA_HIP09_PORT_CFG_REG(port_id)    (0x800 + \
                                                (port_id) * 0x20)
#define HISI_DMA_HIP09_PORT_CFG_LINK_DOWN_MASK_B        BIT(16)

#define HISI_DMA_HIP09_MAX_PORT_NUM             16

#define HISI_DMA_HIP08_MSI_NUM                  32
#define HISI_DMA_HIP08_CHAN_NUM                 30
#define HISI_DMA_HIP09_MSI_NUM                  4
#define HISI_DMA_HIP09_CHAN_NUM                 4
#define HISI_DMA_REVISION_HIP08B                0x21
#define HISI_DMA_REVISION_HIP09A                0x30

#define HISI_DMA_Q_OFFSET                       0x100
#define HISI_DMA_Q_DEPTH_VAL                    1024

#define PCI_BAR_2                               2

#define HISI_DMA_POLL_Q_STS_DELAY_US            10
#define HISI_DMA_POLL_Q_STS_TIME_OUT_US         1000

#define HISI_DMA_MAX_DIR_NAME_LEN               128

/*
 * The HIP08B(HiSilicon IP08) and HIP09A(HiSilicon IP09) are DMA iEPs, they
 * have the same pci device id but different pci revision.
 * Unfortunately, they have different register layouts, so two layout
 * enumerations are defined.
 */
enum hisi_dma_reg_layout {
        HISI_DMA_REG_LAYOUT_INVALID = 0,
        HISI_DMA_REG_LAYOUT_HIP08,
        HISI_DMA_REG_LAYOUT_HIP09
};

enum hisi_dma_mode {
        EP = 0,
        RC,
};

enum hisi_dma_chan_status {
        DISABLE = -1,
        IDLE = 0,
        RUN,
        CPL,
        PAUSE,
        HALT,
        ABORT,
        WAIT,
        BUFFCLR,
};

struct hisi_dma_sqe {
        __le32 dw0;
#define OPCODE_MASK                     GENMASK(3, 0)
#define OPCODE_SMALL_PACKAGE            0x1
#define OPCODE_M2M                      0x4
#define LOCAL_IRQ_EN                    BIT(8)
#define ATTR_SRC_MASK                   GENMASK(14, 12)
        __le32 dw1;
        __le32 dw2;
#define ATTR_DST_MASK                   GENMASK(26, 24)
        __le32 length;
        __le64 src_addr;
        __le64 dst_addr;
};

struct hisi_dma_cqe {
        __le32 rsv0;
        __le32 rsv1;
        __le16 sq_head;
        __le16 rsv2;
        __le16 rsv3;
        __le16 w0;
#define STATUS_MASK                     GENMASK(15, 1)
#define STATUS_SUCC                     0x0
#define VALID_BIT                       BIT(0)
};

struct hisi_dma_desc {
        struct virt_dma_desc vd;
        struct hisi_dma_sqe sqe;
};

struct hisi_dma_chan {
        struct virt_dma_chan vc;
        struct hisi_dma_dev *hdma_dev;
        struct hisi_dma_sqe *sq;
        struct hisi_dma_cqe *cq;
        dma_addr_t sq_dma;
        dma_addr_t cq_dma;
        u32 sq_tail;
        u32 cq_head;
        u32 qp_num;
        enum hisi_dma_chan_status status;
        struct hisi_dma_desc *desc;
};

struct hisi_dma_dev {
        struct pci_dev *pdev;
        void __iomem *base;
        struct dma_device dma_dev;
        u32 chan_num;
        u32 chan_depth;
        enum hisi_dma_reg_layout reg_layout;
        void __iomem *queue_base; /* queue region start of register */
        struct hisi_dma_chan chan[] __counted_by(chan_num);
};

#ifdef CONFIG_DEBUG_FS

static const struct debugfs_reg32 hisi_dma_comm_chan_regs[] = {
        {"DMA_QUEUE_SQ_DEPTH                ", 0x0008ull},
        {"DMA_QUEUE_SQ_TAIL_PTR             ", 0x000Cull},
        {"DMA_QUEUE_CQ_DEPTH                ", 0x0018ull},
        {"DMA_QUEUE_CQ_HEAD_PTR             ", 0x001Cull},
        {"DMA_QUEUE_CTRL0                   ", 0x0020ull},
        {"DMA_QUEUE_CTRL1                   ", 0x0024ull},
        {"DMA_QUEUE_FSM_STS                 ", 0x0030ull},
        {"DMA_QUEUE_SQ_STS                  ", 0x0034ull},
        {"DMA_QUEUE_CQ_TAIL_PTR             ", 0x003Cull},
        {"DMA_QUEUE_INT_STS                 ", 0x0040ull},
        {"DMA_QUEUE_INT_MSK                 ", 0x0044ull},
        {"DMA_QUEUE_INT_RO                  ", 0x006Cull},
};

static const struct debugfs_reg32 hisi_dma_hip08_chan_regs[] = {
        {"DMA_QUEUE_BYTE_CNT                ", 0x0038ull},
        {"DMA_ERR_INT_NUM6                  ", 0x0048ull},
        {"DMA_QUEUE_DESP0                   ", 0x0050ull},
        {"DMA_QUEUE_DESP1                   ", 0x0054ull},
        {"DMA_QUEUE_DESP2                   ", 0x0058ull},
        {"DMA_QUEUE_DESP3                   ", 0x005Cull},
        {"DMA_QUEUE_DESP4                   ", 0x0074ull},
        {"DMA_QUEUE_DESP5                   ", 0x0078ull},
        {"DMA_QUEUE_DESP6                   ", 0x007Cull},
        {"DMA_QUEUE_DESP7                   ", 0x0080ull},
        {"DMA_ERR_INT_NUM0                  ", 0x0084ull},
        {"DMA_ERR_INT_NUM1                  ", 0x0088ull},
        {"DMA_ERR_INT_NUM2                  ", 0x008Cull},
        {"DMA_ERR_INT_NUM3                  ", 0x0090ull},
        {"DMA_ERR_INT_NUM4                  ", 0x0094ull},
        {"DMA_ERR_INT_NUM5                  ", 0x0098ull},
        {"DMA_QUEUE_SQ_STS2                 ", 0x00A4ull},
};

static const struct debugfs_reg32 hisi_dma_hip09_chan_regs[] = {
        {"DMA_QUEUE_ERR_INT_STS             ", 0x0048ull},
        {"DMA_QUEUE_ERR_INT_MSK             ", 0x004Cull},
        {"DFX_SQ_READ_ERR_PTR               ", 0x0068ull},
        {"DFX_DMA_ERR_INT_NUM0              ", 0x0084ull},
        {"DFX_DMA_ERR_INT_NUM1              ", 0x0088ull},
        {"DFX_DMA_ERR_INT_NUM2              ", 0x008Cull},
        {"DFX_DMA_QUEUE_SQ_STS2             ", 0x00A4ull},
};

static const struct debugfs_reg32 hisi_dma_hip08_comm_regs[] = {
        {"DMA_ECC_ERR_ADDR                  ", 0x2004ull},
        {"DMA_ECC_ECC_CNT                   ", 0x2014ull},
        {"COMMON_AND_CH_ERR_STS             ", 0x2030ull},
        {"LOCAL_CPL_ID_STS_0                ", 0x20E0ull},
        {"LOCAL_CPL_ID_STS_1                ", 0x20E4ull},
        {"LOCAL_CPL_ID_STS_2                ", 0x20E8ull},
        {"LOCAL_CPL_ID_STS_3                ", 0x20ECull},
        {"LOCAL_TLP_NUM                     ", 0x2158ull},
        {"SQCQ_TLP_NUM                      ", 0x2164ull},
        {"CPL_NUM                           ", 0x2168ull},
        {"INF_BACK_PRESS_STS                ", 0x2170ull},
        {"DMA_CH_RAS_LEVEL                  ", 0x2184ull},
        {"DMA_CM_RAS_LEVEL                  ", 0x2188ull},
        {"DMA_CH_ERR_STS                    ", 0x2190ull},
        {"DMA_CH_DONE_STS                   ", 0x2194ull},
        {"DMA_SQ_TAG_STS_0                  ", 0x21A0ull},
        {"DMA_SQ_TAG_STS_1                  ", 0x21A4ull},
        {"DMA_SQ_TAG_STS_2                  ", 0x21A8ull},
        {"DMA_SQ_TAG_STS_3                  ", 0x21ACull},
        {"LOCAL_P_ID_STS_0                  ", 0x21B0ull},
        {"LOCAL_P_ID_STS_1                  ", 0x21B4ull},
        {"LOCAL_P_ID_STS_2                  ", 0x21B8ull},
        {"LOCAL_P_ID_STS_3                  ", 0x21BCull},
        {"DMA_PREBUFF_INFO_0                ", 0x2200ull},
        {"DMA_CM_TABLE_INFO_0               ", 0x2220ull},
        {"DMA_CM_CE_RO                      ", 0x2244ull},
        {"DMA_CM_NFE_RO                     ", 0x2248ull},
        {"DMA_CM_FE_RO                      ", 0x224Cull},
};

static const struct debugfs_reg32 hisi_dma_hip09_comm_regs[] = {
        {"COMMON_AND_CH_ERR_STS             ", 0x0030ull},
        {"DMA_PORT_IDLE_STS                 ", 0x0150ull},
        {"DMA_CH_RAS_LEVEL                  ", 0x0184ull},
        {"DMA_CM_RAS_LEVEL                  ", 0x0188ull},
        {"DMA_CM_CE_RO                      ", 0x0244ull},
        {"DMA_CM_NFE_RO                     ", 0x0248ull},
        {"DMA_CM_FE_RO                      ", 0x024Cull},
        {"DFX_INF_BACK_PRESS_STS0           ", 0x1A40ull},
        {"DFX_INF_BACK_PRESS_STS1           ", 0x1A44ull},
        {"DFX_INF_BACK_PRESS_STS2           ", 0x1A48ull},
        {"DFX_DMA_WRR_DISABLE               ", 0x1A4Cull},
        {"DFX_PA_REQ_TLP_NUM                ", 0x1C00ull},
        {"DFX_PA_BACK_TLP_NUM               ", 0x1C04ull},
        {"DFX_PA_RETRY_TLP_NUM              ", 0x1C08ull},
        {"DFX_LOCAL_NP_TLP_NUM              ", 0x1C0Cull},
        {"DFX_LOCAL_CPL_HEAD_TLP_NUM        ", 0x1C10ull},
        {"DFX_LOCAL_CPL_DATA_TLP_NUM        ", 0x1C14ull},
        {"DFX_LOCAL_CPL_EXT_DATA_TLP_NUM    ", 0x1C18ull},
        {"DFX_LOCAL_P_HEAD_TLP_NUM          ", 0x1C1Cull},
        {"DFX_LOCAL_P_ACK_TLP_NUM           ", 0x1C20ull},
        {"DFX_BUF_ALOC_PORT_REQ_NUM         ", 0x1C24ull},
        {"DFX_BUF_ALOC_PORT_RESULT_NUM      ", 0x1C28ull},
        {"DFX_BUF_FAIL_SIZE_NUM             ", 0x1C2Cull},
        {"DFX_BUF_ALOC_SIZE_NUM             ", 0x1C30ull},
        {"DFX_BUF_NP_RELEASE_SIZE_NUM       ", 0x1C34ull},
        {"DFX_BUF_P_RELEASE_SIZE_NUM        ", 0x1C38ull},
        {"DFX_BUF_PORT_RELEASE_SIZE_NUM     ", 0x1C3Cull},
        {"DFX_DMA_PREBUF_MEM0_ECC_ERR_ADDR  ", 0x1CA8ull},
        {"DFX_DMA_PREBUF_MEM0_ECC_CNT       ", 0x1CACull},
        {"DFX_DMA_LOC_NP_OSTB_ECC_ERR_ADDR  ", 0x1CB0ull},
        {"DFX_DMA_LOC_NP_OSTB_ECC_CNT       ", 0x1CB4ull},
        {"DFX_DMA_PREBUF_MEM1_ECC_ERR_ADDR  ", 0x1CC0ull},
        {"DFX_DMA_PREBUF_MEM1_ECC_CNT       ", 0x1CC4ull},
        {"DMA_CH_DONE_STS                   ", 0x02E0ull},
        {"DMA_CH_ERR_STS                    ", 0x0320ull},
};
#endif /* CONFIG_DEBUG_FS*/

static enum hisi_dma_reg_layout hisi_dma_get_reg_layout(struct pci_dev *pdev)
{
        if (pdev->revision == HISI_DMA_REVISION_HIP08B)
                return HISI_DMA_REG_LAYOUT_HIP08;
        else if (pdev->revision >= HISI_DMA_REVISION_HIP09A)
                return HISI_DMA_REG_LAYOUT_HIP09;

        return HISI_DMA_REG_LAYOUT_INVALID;
}

static u32 hisi_dma_get_chan_num(struct pci_dev *pdev)
{
        if (pdev->revision == HISI_DMA_REVISION_HIP08B)
                return HISI_DMA_HIP08_CHAN_NUM;

        return HISI_DMA_HIP09_CHAN_NUM;
}

static u32 hisi_dma_get_msi_num(struct pci_dev *pdev)
{
        if (pdev->revision == HISI_DMA_REVISION_HIP08B)
                return HISI_DMA_HIP08_MSI_NUM;

        return HISI_DMA_HIP09_MSI_NUM;
}

static u32 hisi_dma_get_queue_base(struct pci_dev *pdev)
{
        if (pdev->revision == HISI_DMA_REVISION_HIP08B)
                return HISI_DMA_HIP08_Q_BASE;

        return HISI_DMA_HIP09_Q_BASE;
}

static inline struct hisi_dma_chan *to_hisi_dma_chan(struct dma_chan *c)
{
        return container_of(c, struct hisi_dma_chan, vc.chan);
}

static inline struct hisi_dma_desc *to_hisi_dma_desc(struct virt_dma_desc *vd)
{
        return container_of(vd, struct hisi_dma_desc, vd);
}

static inline void hisi_dma_chan_write(void __iomem *base, u32 reg, u32 index,
                                       u32 val)
{
        writel_relaxed(val, base + reg + index * HISI_DMA_Q_OFFSET);
}

static inline void hisi_dma_update_bit(void __iomem *addr, u32 pos, bool val)
{
        u32 tmp;

        tmp = readl_relaxed(addr);
        tmp = val ? tmp | pos : tmp & ~pos;
        writel_relaxed(tmp, addr);
}

static void hisi_dma_pause_dma(struct hisi_dma_dev *hdma_dev, u32 index,
                               bool pause)
{
        void __iomem *addr;

        addr = hdma_dev->queue_base + HISI_DMA_Q_CTRL0 +
               index * HISI_DMA_Q_OFFSET;
        hisi_dma_update_bit(addr, HISI_DMA_Q_CTRL0_QUEUE_PAUSE, pause);
}

static void hisi_dma_enable_dma(struct hisi_dma_dev *hdma_dev, u32 index,
                                bool enable)
{
        void __iomem *addr;

        addr = hdma_dev->queue_base + HISI_DMA_Q_CTRL0 +
               index * HISI_DMA_Q_OFFSET;
        hisi_dma_update_bit(addr, HISI_DMA_Q_CTRL0_QUEUE_EN, enable);
}

static void hisi_dma_mask_irq(struct hisi_dma_dev *hdma_dev, u32 qp_index)
{
        void __iomem *q_base = hdma_dev->queue_base;

        if (hdma_dev->reg_layout == HISI_DMA_REG_LAYOUT_HIP08)
                hisi_dma_chan_write(q_base, HISI_DMA_HIP08_Q_INT_MSK,
                                    qp_index, HISI_DMA_HIP08_Q_INT_STS_MASK);
        else {
                hisi_dma_chan_write(q_base, HISI_DMA_HIP09_Q_INT_MSK,
                                    qp_index, HISI_DMA_HIP09_Q_INT_STS_MASK);
                hisi_dma_chan_write(q_base, HISI_DMA_HIP09_Q_ERR_INT_MSK,
                                    qp_index,
                                    HISI_DMA_HIP09_Q_ERR_INT_STS_MASK);
        }
}

static void hisi_dma_unmask_irq(struct hisi_dma_dev *hdma_dev, u32 qp_index)
{
        void __iomem *q_base = hdma_dev->queue_base;

        if (hdma_dev->reg_layout == HISI_DMA_REG_LAYOUT_HIP08) {
                hisi_dma_chan_write(q_base, HISI_DMA_HIP08_Q_INT_STS,
                                    qp_index, HISI_DMA_HIP08_Q_INT_STS_MASK);
                hisi_dma_chan_write(q_base, HISI_DMA_HIP08_Q_INT_MSK,
                                    qp_index, 0);
        } else {
                hisi_dma_chan_write(q_base, HISI_DMA_HIP09_Q_INT_STS,
                                    qp_index, HISI_DMA_HIP09_Q_INT_STS_MASK);
                hisi_dma_chan_write(q_base, HISI_DMA_HIP09_Q_ERR_INT_STS,
                                    qp_index,
                                    HISI_DMA_HIP09_Q_ERR_INT_STS_MASK);
                hisi_dma_chan_write(q_base, HISI_DMA_HIP09_Q_INT_MSK,
                                    qp_index, 0);
                hisi_dma_chan_write(q_base, HISI_DMA_HIP09_Q_ERR_INT_MSK,
                                    qp_index, 0);
        }
}

static void hisi_dma_do_reset(struct hisi_dma_dev *hdma_dev, u32 index)
{
        void __iomem *addr;

        addr = hdma_dev->queue_base +
               HISI_DMA_Q_CTRL1 + index * HISI_DMA_Q_OFFSET;
        hisi_dma_update_bit(addr, HISI_DMA_Q_CTRL1_QUEUE_RESET, 1);
}

static void hisi_dma_reset_qp_point(struct hisi_dma_dev *hdma_dev, u32 index)
{
        void __iomem *q_base = hdma_dev->queue_base;

        hisi_dma_chan_write(q_base, HISI_DMA_Q_SQ_TAIL_PTR, index, 0);
        hisi_dma_chan_write(q_base, HISI_DMA_Q_CQ_HEAD_PTR, index, 0);
}

static void hisi_dma_reset_or_disable_hw_chan(struct hisi_dma_chan *chan,
                                              bool disable)
{
        struct hisi_dma_dev *hdma_dev = chan->hdma_dev;
        u32 index = chan->qp_num, tmp;
        void __iomem *addr;
        int ret;

        hisi_dma_pause_dma(hdma_dev, index, true);
        hisi_dma_enable_dma(hdma_dev, index, false);
        hisi_dma_mask_irq(hdma_dev, index);

        addr = hdma_dev->queue_base +
               HISI_DMA_Q_FSM_STS + index * HISI_DMA_Q_OFFSET;

        ret = readl_relaxed_poll_timeout(addr, tmp,
                FIELD_GET(HISI_DMA_Q_FSM_STS_MASK, tmp) != RUN,
                HISI_DMA_POLL_Q_STS_DELAY_US, HISI_DMA_POLL_Q_STS_TIME_OUT_US);
        if (ret) {
                dev_err(&hdma_dev->pdev->dev, "disable channel timeout!\n");
                WARN_ON(1);
        }

        hisi_dma_do_reset(hdma_dev, index);
        hisi_dma_reset_qp_point(hdma_dev, index);
        hisi_dma_pause_dma(hdma_dev, index, false);

        if (!disable) {
                hisi_dma_enable_dma(hdma_dev, index, true);
                hisi_dma_unmask_irq(hdma_dev, index);
        }

        ret = readl_relaxed_poll_timeout(addr, tmp,
                FIELD_GET(HISI_DMA_Q_FSM_STS_MASK, tmp) == IDLE,
                HISI_DMA_POLL_Q_STS_DELAY_US, HISI_DMA_POLL_Q_STS_TIME_OUT_US);
        if (ret) {
                dev_err(&hdma_dev->pdev->dev, "reset channel timeout!\n");
                WARN_ON(1);
        }
}

static void hisi_dma_free_chan_resources(struct dma_chan *c)
{
        struct hisi_dma_chan *chan = to_hisi_dma_chan(c);
        struct hisi_dma_dev *hdma_dev = chan->hdma_dev;

        hisi_dma_reset_or_disable_hw_chan(chan, false);
        vchan_free_chan_resources(&chan->vc);

        memset(chan->sq, 0, sizeof(struct hisi_dma_sqe) * hdma_dev->chan_depth);
        memset(chan->cq, 0, sizeof(struct hisi_dma_cqe) * hdma_dev->chan_depth);
        chan->sq_tail = 0;
        chan->cq_head = 0;
        chan->status = DISABLE;
}

static void hisi_dma_desc_free(struct virt_dma_desc *vd)
{
        kfree(to_hisi_dma_desc(vd));
}

static struct dma_async_tx_descriptor *
hisi_dma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dst, dma_addr_t src,
                         size_t len, unsigned long flags)
{
        struct hisi_dma_chan *chan = to_hisi_dma_chan(c);
        struct hisi_dma_desc *desc;

        desc = kzalloc_obj(*desc, GFP_NOWAIT);
        if (!desc)
                return NULL;

        desc->sqe.length = cpu_to_le32(len);
        desc->sqe.src_addr = cpu_to_le64(src);
        desc->sqe.dst_addr = cpu_to_le64(dst);

        return vchan_tx_prep(&chan->vc, &desc->vd, flags);
}

static enum dma_status
hisi_dma_tx_status(struct dma_chan *c, dma_cookie_t cookie,
                   struct dma_tx_state *txstate)
{
        return dma_cookie_status(c, cookie, txstate);
}

static void hisi_dma_start_transfer(struct hisi_dma_chan *chan)
{
        struct hisi_dma_sqe *sqe = chan->sq + chan->sq_tail;
        struct hisi_dma_dev *hdma_dev = chan->hdma_dev;
        struct hisi_dma_desc *desc;
        struct virt_dma_desc *vd;

        vd = vchan_next_desc(&chan->vc);
        if (!vd) {
                chan->desc = NULL;
                return;
        }
        list_del(&vd->node);
        desc = to_hisi_dma_desc(vd);
        chan->desc = desc;

        memcpy(sqe, &desc->sqe, sizeof(struct hisi_dma_sqe));

        /* update other field in sqe */
        sqe->dw0 = cpu_to_le32(FIELD_PREP(OPCODE_MASK, OPCODE_M2M));
        sqe->dw0 |= cpu_to_le32(LOCAL_IRQ_EN);

        /* make sure data has been updated in sqe */
        wmb();

        /* update sq tail, point to new sqe position */
        chan->sq_tail = (chan->sq_tail + 1) % hdma_dev->chan_depth;

        /* update sq_tail to trigger a new task */
        hisi_dma_chan_write(hdma_dev->queue_base, HISI_DMA_Q_SQ_TAIL_PTR,
                            chan->qp_num, chan->sq_tail);
}

static void hisi_dma_issue_pending(struct dma_chan *c)
{
        struct hisi_dma_chan *chan = to_hisi_dma_chan(c);
        unsigned long flags;

        spin_lock_irqsave(&chan->vc.lock, flags);

        if (vchan_issue_pending(&chan->vc) && !chan->desc)
                hisi_dma_start_transfer(chan);

        spin_unlock_irqrestore(&chan->vc.lock, flags);
}

static int hisi_dma_terminate_all(struct dma_chan *c)
{
        struct hisi_dma_chan *chan = to_hisi_dma_chan(c);
        unsigned long flags;
        LIST_HEAD(head);

        spin_lock_irqsave(&chan->vc.lock, flags);

        hisi_dma_pause_dma(chan->hdma_dev, chan->qp_num, true);
        if (chan->desc) {
                vchan_terminate_vdesc(&chan->desc->vd);
                chan->desc = NULL;
        }

        vchan_get_all_descriptors(&chan->vc, &head);

        spin_unlock_irqrestore(&chan->vc.lock, flags);

        vchan_dma_desc_free_list(&chan->vc, &head);
        hisi_dma_pause_dma(chan->hdma_dev, chan->qp_num, false);

        return 0;
}

static void hisi_dma_synchronize(struct dma_chan *c)
{
        struct hisi_dma_chan *chan = to_hisi_dma_chan(c);

        vchan_synchronize(&chan->vc);
}

static int hisi_dma_alloc_qps_mem(struct hisi_dma_dev *hdma_dev)
{
        size_t sq_size = sizeof(struct hisi_dma_sqe) * hdma_dev->chan_depth;
        size_t cq_size = sizeof(struct hisi_dma_cqe) * hdma_dev->chan_depth;
        struct device *dev = &hdma_dev->pdev->dev;
        struct hisi_dma_chan *chan;
        int i;

        for (i = 0; i < hdma_dev->chan_num; i++) {
                chan = &hdma_dev->chan[i];
                chan->sq = dmam_alloc_coherent(dev, sq_size, &chan->sq_dma,
                                               GFP_KERNEL);
                if (!chan->sq)
                        return -ENOMEM;

                chan->cq = dmam_alloc_coherent(dev, cq_size, &chan->cq_dma,
                                               GFP_KERNEL);
                if (!chan->cq)
                        return -ENOMEM;
        }

        return 0;
}

static void hisi_dma_init_hw_qp(struct hisi_dma_dev *hdma_dev, u32 index)
{
        struct hisi_dma_chan *chan = &hdma_dev->chan[index];
        void __iomem *q_base = hdma_dev->queue_base;
        u32 hw_depth = hdma_dev->chan_depth - 1;
        void __iomem *addr;
        u32 tmp;

        /* set sq, cq base */
        hisi_dma_chan_write(q_base, HISI_DMA_Q_SQ_BASE_L, index,
                            lower_32_bits(chan->sq_dma));
        hisi_dma_chan_write(q_base, HISI_DMA_Q_SQ_BASE_H, index,
                            upper_32_bits(chan->sq_dma));
        hisi_dma_chan_write(q_base, HISI_DMA_Q_CQ_BASE_L, index,
                            lower_32_bits(chan->cq_dma));
        hisi_dma_chan_write(q_base, HISI_DMA_Q_CQ_BASE_H, index,
                            upper_32_bits(chan->cq_dma));

        /* set sq, cq depth */
        hisi_dma_chan_write(q_base, HISI_DMA_Q_SQ_DEPTH, index, hw_depth);
        hisi_dma_chan_write(q_base, HISI_DMA_Q_CQ_DEPTH, index, hw_depth);

        /* init sq tail and cq head */
        hisi_dma_chan_write(q_base, HISI_DMA_Q_SQ_TAIL_PTR, index, 0);
        hisi_dma_chan_write(q_base, HISI_DMA_Q_CQ_HEAD_PTR, index, 0);

        /* init error interrupt stats */
        hisi_dma_chan_write(q_base, HISI_DMA_Q_ERR_INT_NUM0, index, 0);
        hisi_dma_chan_write(q_base, HISI_DMA_Q_ERR_INT_NUM1, index, 0);
        hisi_dma_chan_write(q_base, HISI_DMA_Q_ERR_INT_NUM2, index, 0);

        if (hdma_dev->reg_layout == HISI_DMA_REG_LAYOUT_HIP08) {
                hisi_dma_chan_write(q_base, HISI_DMA_HIP08_Q_ERR_INT_NUM3,
                                    index, 0);
                hisi_dma_chan_write(q_base, HISI_DMA_HIP08_Q_ERR_INT_NUM4,
                                    index, 0);
                hisi_dma_chan_write(q_base, HISI_DMA_HIP08_Q_ERR_INT_NUM5,
                                    index, 0);
                hisi_dma_chan_write(q_base, HISI_DMA_HIP08_Q_ERR_INT_NUM6,
                                    index, 0);
                /*
                 * init SQ/CQ direction selecting register.
                 * "0" is to local side and "1" is to remote side.
                 */
                addr = q_base + HISI_DMA_Q_CTRL0 + index * HISI_DMA_Q_OFFSET;
                hisi_dma_update_bit(addr, HISI_DMA_HIP08_Q_CTRL0_SQCQ_DRCT, 0);

                /*
                 * 0 - Continue to next descriptor if error occurs.
                 * 1 - Abort the DMA queue if error occurs.
                 */
                hisi_dma_update_bit(addr,
                                    HISI_DMA_HIP08_Q_CTRL0_ERR_ABORT_EN, 0);
        } else {
                addr = q_base + HISI_DMA_Q_CTRL0 + index * HISI_DMA_Q_OFFSET;

                /*
                 * init SQ/CQ direction selecting register.
                 * "0" is to local side and "1" is to remote side.
                 */
                hisi_dma_update_bit(addr, HISI_DMA_HIP09_Q_CTRL0_SQ_DRCT, 0);
                hisi_dma_update_bit(addr, HISI_DMA_HIP09_Q_CTRL0_CQ_DRCT, 0);

                /*
                 * 0 - Continue to next descriptor if error occurs.
                 * 1 - Abort the DMA queue if error occurs.
                 */

                tmp = readl_relaxed(addr);
                tmp &= ~HISI_DMA_HIP09_Q_CTRL0_ERR_ABORT_EN;
                writel_relaxed(tmp, addr);

                /*
                 * 0 - dma should process FLR with CPU.
                 * 1 - dma not process FLR, only cpu process FLR.
                 */
                addr = q_base + HISI_DMA_HIP09_DMA_FLR_DISABLE +
                       index * HISI_DMA_Q_OFFSET;
                hisi_dma_update_bit(addr, HISI_DMA_HIP09_DMA_FLR_DISABLE_B, 0);

                addr = q_base + HISI_DMA_Q_CTRL1 + index * HISI_DMA_Q_OFFSET;
                hisi_dma_update_bit(addr, HISI_DMA_HIP09_Q_CTRL1_VA_ENABLE, 1);
        }
}

static void hisi_dma_enable_qp(struct hisi_dma_dev *hdma_dev, u32 qp_index)
{
        hisi_dma_init_hw_qp(hdma_dev, qp_index);
        hisi_dma_unmask_irq(hdma_dev, qp_index);
        hisi_dma_enable_dma(hdma_dev, qp_index, true);
}

static void hisi_dma_disable_qp(struct hisi_dma_dev *hdma_dev, u32 qp_index)
{
        hisi_dma_reset_or_disable_hw_chan(&hdma_dev->chan[qp_index], true);
}

static void hisi_dma_enable_qps(struct hisi_dma_dev *hdma_dev)
{
        int i;

        for (i = 0; i < hdma_dev->chan_num; i++) {
                hdma_dev->chan[i].qp_num = i;
                hdma_dev->chan[i].hdma_dev = hdma_dev;
                hdma_dev->chan[i].vc.desc_free = hisi_dma_desc_free;
                vchan_init(&hdma_dev->chan[i].vc, &hdma_dev->dma_dev);
                hisi_dma_enable_qp(hdma_dev, i);
        }
}

static void hisi_dma_disable_qps(struct hisi_dma_dev *hdma_dev)
{
        int i;

        for (i = 0; i < hdma_dev->chan_num; i++) {
                hisi_dma_disable_qp(hdma_dev, i);
                tasklet_kill(&hdma_dev->chan[i].vc.task);
        }
}

static irqreturn_t hisi_dma_irq(int irq, void *data)
{
        struct hisi_dma_chan *chan = data;
        struct hisi_dma_dev *hdma_dev = chan->hdma_dev;
        struct hisi_dma_desc *desc;
        struct hisi_dma_cqe *cqe;
        void __iomem *q_base;

        spin_lock(&chan->vc.lock);

        desc = chan->desc;
        cqe = chan->cq + chan->cq_head;
        q_base = hdma_dev->queue_base;
        if (desc) {
                chan->cq_head = (chan->cq_head + 1) % hdma_dev->chan_depth;
                hisi_dma_chan_write(q_base, HISI_DMA_Q_CQ_HEAD_PTR,
                                    chan->qp_num, chan->cq_head);
                if (FIELD_GET(STATUS_MASK, cqe->w0) == STATUS_SUCC) {
                        vchan_cookie_complete(&desc->vd);
                        hisi_dma_start_transfer(chan);
                } else {
                        dev_err(&hdma_dev->pdev->dev, "task error!\n");
                }
        }

        spin_unlock(&chan->vc.lock);

        return IRQ_HANDLED;
}

static int hisi_dma_request_qps_irq(struct hisi_dma_dev *hdma_dev)
{
        struct pci_dev *pdev = hdma_dev->pdev;
        int i, ret;

        for (i = 0; i < hdma_dev->chan_num; i++) {
                ret = devm_request_irq(&pdev->dev, pci_irq_vector(pdev, i),
                                       hisi_dma_irq, IRQF_SHARED, "hisi_dma",
                                       &hdma_dev->chan[i]);
                if (ret)
                        return ret;
        }

        return 0;
}

/* This function enables all hw channels in a device */
static int hisi_dma_enable_hw_channels(struct hisi_dma_dev *hdma_dev)
{
        int ret;

        ret = hisi_dma_alloc_qps_mem(hdma_dev);
        if (ret) {
                dev_err(&hdma_dev->pdev->dev, "fail to allocate qp memory!\n");
                return ret;
        }

        ret = hisi_dma_request_qps_irq(hdma_dev);
        if (ret) {
                dev_err(&hdma_dev->pdev->dev, "fail to request qp irq!\n");
                return ret;
        }

        hisi_dma_enable_qps(hdma_dev);

        return 0;
}

static void hisi_dma_disable_hw_channels(void *data)
{
        hisi_dma_disable_qps(data);
}

static void hisi_dma_set_mode(struct hisi_dma_dev *hdma_dev,
                              enum hisi_dma_mode mode)
{
        if (hdma_dev->reg_layout == HISI_DMA_REG_LAYOUT_HIP08)
                writel_relaxed(mode == RC ? 1 : 0,
                               hdma_dev->base + HISI_DMA_HIP08_MODE);
}

static void hisi_dma_init_hw(struct hisi_dma_dev *hdma_dev)
{
        void __iomem *addr;
        int i;

        if (hdma_dev->reg_layout == HISI_DMA_REG_LAYOUT_HIP09) {
                for (i = 0; i < HISI_DMA_HIP09_MAX_PORT_NUM; i++) {
                        addr = hdma_dev->base + HISI_DMA_HIP09_PORT_CFG_REG(i);
                        hisi_dma_update_bit(addr,
                                HISI_DMA_HIP09_PORT_CFG_LINK_DOWN_MASK_B, 1);
                }
        }
}

static void hisi_dma_init_dma_dev(struct hisi_dma_dev *hdma_dev)
{
        struct dma_device *dma_dev;

        dma_dev = &hdma_dev->dma_dev;
        dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
        dma_dev->device_free_chan_resources = hisi_dma_free_chan_resources;
        dma_dev->device_prep_dma_memcpy = hisi_dma_prep_dma_memcpy;
        dma_dev->device_tx_status = hisi_dma_tx_status;
        dma_dev->device_issue_pending = hisi_dma_issue_pending;
        dma_dev->device_terminate_all = hisi_dma_terminate_all;
        dma_dev->device_synchronize = hisi_dma_synchronize;
        dma_dev->directions = BIT(DMA_MEM_TO_MEM);
        dma_dev->dev = &hdma_dev->pdev->dev;
        INIT_LIST_HEAD(&dma_dev->channels);
}

/* --- debugfs implementation --- */
#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>
static struct debugfs_reg32 *hisi_dma_get_ch_regs(struct hisi_dma_dev *hdma_dev,
                                                  u32 *regs_sz)
{
        struct device *dev = &hdma_dev->pdev->dev;
        struct debugfs_reg32 *regs;
        u32 regs_sz_comm;

        regs_sz_comm = ARRAY_SIZE(hisi_dma_comm_chan_regs);

        if (hdma_dev->reg_layout == HISI_DMA_REG_LAYOUT_HIP08)
                *regs_sz = regs_sz_comm + ARRAY_SIZE(hisi_dma_hip08_chan_regs);
        else
                *regs_sz = regs_sz_comm + ARRAY_SIZE(hisi_dma_hip09_chan_regs);

        regs = devm_kcalloc(dev, *regs_sz, sizeof(struct debugfs_reg32),
                            GFP_KERNEL);
        if (!regs)
                return NULL;
        memcpy(regs, hisi_dma_comm_chan_regs, sizeof(hisi_dma_comm_chan_regs));

        if (hdma_dev->reg_layout == HISI_DMA_REG_LAYOUT_HIP08)
                memcpy(regs + regs_sz_comm, hisi_dma_hip08_chan_regs,
                       sizeof(hisi_dma_hip08_chan_regs));
        else
                memcpy(regs + regs_sz_comm, hisi_dma_hip09_chan_regs,
                       sizeof(hisi_dma_hip09_chan_regs));

        return regs;
}

static int hisi_dma_create_chan_dir(struct hisi_dma_dev *hdma_dev)
{
        char dir_name[HISI_DMA_MAX_DIR_NAME_LEN];
        struct debugfs_regset32 *regsets;
        struct debugfs_reg32 *regs;
        struct dentry *chan_dir;
        struct device *dev;
        u32 regs_sz;
        int ret;
        int i;

        dev = &hdma_dev->pdev->dev;

        regsets = devm_kcalloc(dev, hdma_dev->chan_num,
                               sizeof(*regsets), GFP_KERNEL);
        if (!regsets)
                return -ENOMEM;

        regs = hisi_dma_get_ch_regs(hdma_dev, &regs_sz);
        if (!regs)
                return -ENOMEM;

        for (i = 0; i < hdma_dev->chan_num; i++) {
                regsets[i].regs = regs;
                regsets[i].nregs = regs_sz;
                regsets[i].base = hdma_dev->queue_base + i * HISI_DMA_Q_OFFSET;
                regsets[i].dev = dev;

                memset(dir_name, 0, HISI_DMA_MAX_DIR_NAME_LEN);
                ret = sprintf(dir_name, "channel%d", i);
                if (ret < 0)
                        return ret;

                chan_dir = debugfs_create_dir(dir_name,
                                              hdma_dev->dma_dev.dbg_dev_root);
                debugfs_create_regset32("regs", 0444, chan_dir, &regsets[i]);
        }

        return 0;
}

static void hisi_dma_create_debugfs(struct hisi_dma_dev *hdma_dev)
{
        struct debugfs_regset32 *regset;
        struct device *dev;
        int ret;

        dev = &hdma_dev->pdev->dev;

        if (hdma_dev->dma_dev.dbg_dev_root == NULL)
                return;

        regset = devm_kzalloc(dev, sizeof(*regset), GFP_KERNEL);
        if (!regset)
                return;

        if (hdma_dev->reg_layout == HISI_DMA_REG_LAYOUT_HIP08) {
                regset->regs = hisi_dma_hip08_comm_regs;
                regset->nregs = ARRAY_SIZE(hisi_dma_hip08_comm_regs);
        } else {
                regset->regs = hisi_dma_hip09_comm_regs;
                regset->nregs = ARRAY_SIZE(hisi_dma_hip09_comm_regs);
        }
        regset->base = hdma_dev->base;
        regset->dev = dev;

        debugfs_create_regset32("regs", 0444,
                                hdma_dev->dma_dev.dbg_dev_root, regset);

        ret = hisi_dma_create_chan_dir(hdma_dev);
        if (ret < 0)
                dev_info(&hdma_dev->pdev->dev, "fail to create debugfs for channels!\n");
}
#else
static void hisi_dma_create_debugfs(struct hisi_dma_dev *hdma_dev) { }
#endif /* CONFIG_DEBUG_FS*/
/* --- debugfs implementation --- */

static int hisi_dma_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
        enum hisi_dma_reg_layout reg_layout;
        struct device *dev = &pdev->dev;
        struct hisi_dma_dev *hdma_dev;
        struct dma_device *dma_dev;
        u32 chan_num;
        u32 msi_num;
        int ret;

        reg_layout = hisi_dma_get_reg_layout(pdev);
        if (reg_layout == HISI_DMA_REG_LAYOUT_INVALID) {
                dev_err(dev, "unsupported device!\n");
                return -EINVAL;
        }

        ret = pcim_enable_device(pdev);
        if (ret) {
                dev_err(dev, "failed to enable device mem!\n");
                return ret;
        }

        ret = pcim_iomap_regions(pdev, 1 << PCI_BAR_2, pci_name(pdev));
        if (ret) {
                dev_err(dev, "failed to remap I/O region!\n");
                return ret;
        }

        ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
        if (ret)
                return ret;

        chan_num = hisi_dma_get_chan_num(pdev);
        hdma_dev = devm_kzalloc(dev, struct_size(hdma_dev, chan, chan_num),
                                GFP_KERNEL);
        if (!hdma_dev)
                return -EINVAL;

        hdma_dev->base = pcim_iomap_table(pdev)[PCI_BAR_2];
        hdma_dev->pdev = pdev;
        hdma_dev->chan_depth = HISI_DMA_Q_DEPTH_VAL;
        hdma_dev->chan_num = chan_num;
        hdma_dev->reg_layout = reg_layout;
        hdma_dev->queue_base = hdma_dev->base + hisi_dma_get_queue_base(pdev);

        pci_set_drvdata(pdev, hdma_dev);
        pci_set_master(pdev);

        msi_num = hisi_dma_get_msi_num(pdev);

        /* This will be freed by 'pcim_release()'. See 'pcim_enable_device()' */
        ret = pci_alloc_irq_vectors(pdev, msi_num, msi_num, PCI_IRQ_MSI);
        if (ret < 0) {
                dev_err(dev, "Failed to allocate MSI vectors!\n");
                return ret;
        }

        hisi_dma_init_dma_dev(hdma_dev);

        hisi_dma_set_mode(hdma_dev, RC);

        hisi_dma_init_hw(hdma_dev);

        ret = hisi_dma_enable_hw_channels(hdma_dev);
        if (ret < 0) {
                dev_err(dev, "failed to enable hw channel!\n");
                return ret;
        }

        ret = devm_add_action_or_reset(dev, hisi_dma_disable_hw_channels,
                                       hdma_dev);
        if (ret)
                return ret;

        dma_dev = &hdma_dev->dma_dev;
        ret = dmaenginem_async_device_register(dma_dev);
        if (ret < 0) {
                dev_err(dev, "failed to register device!\n");
                return ret;
        }

        hisi_dma_create_debugfs(hdma_dev);

        return 0;
}

static const struct pci_device_id hisi_dma_pci_tbl[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_HUAWEI, 0xa122) },
        { 0, }
};

static struct pci_driver hisi_dma_pci_driver = {
        .name           = "hisi_dma",
        .id_table       = hisi_dma_pci_tbl,
        .probe          = hisi_dma_probe,
};

module_pci_driver(hisi_dma_pci_driver);

MODULE_AUTHOR("Zhou Wang <wangzhou1@hisilicon.com>");
MODULE_AUTHOR("Zhenfa Qiu <qiuzhenfa@hisilicon.com>");
MODULE_DESCRIPTION("HiSilicon Kunpeng DMA controller driver");
MODULE_LICENSE("GPL v2");
MODULE_DEVICE_TABLE(pci, hisi_dma_pci_tbl);