Re: [PATCH v6 3/5] dmaengine: dw-edma: Add support for native HDMA

From: Serge Semin
Date: Sun Mar 12 2023 - 19:11:24 EST

On Fri, Mar 10, 2023 at 11:23:36AM +0800, Cai Huoqing wrote:
> Add support for HDMA NATIVE, as long the IP design has set
> the compatible register map parameter-HDMA_NATIVE,
> which allows compatibility for native HDMA register configuration.
>
> The HDMA Hyper-DMA IP is an enhancement of the eDMA embedded-DMA IP.
> And the native HDMA registers are different from eDMA, so this patch
> add support for HDMA NATIVE mode.
>
> HDMA write and read channels operate independently to maximize
> the performance of the HDMA read and write data transfer over
> the link When you configure the HDMA with multiple read channels,
> then it uses a round robin (RR) arbitration scheme to select
> the next read channel to be serviced.The same applies when you
> have multiple write channels.
>
> The native HDMA driver also supports a maximum of 16 independent
> channels (8 write + 8 read), which can run simultaneously.
> Both SAR (Source Address Register) and DAR (Destination Address Register)
> are aligned to byte.
>
> Signed-off-by: Cai Huoqing <cai.huoqing@xxxxxxxxx>
> ---
> v5->v6:
> 6.Remove some unnecessary wrapper function.
> 7.Using one loop instead two in dw_hdma_v0_core_handle_int.
> 8.Fix the method to returning the actual IRQ-handling status.
>
> v5 link:
> https://lore.kernel.org/lkml/20230303124642.5519-4-cai.huoqing@xxxxxxxxx/
>
> drivers/dma/dw-edma/Makefile | 5 +-
> drivers/dma/dw-edma/dw-edma-core.c | 6 +-
> drivers/dma/dw-edma/dw-hdma-v0-core.c | 275 ++++++++++++++++++++++++++
> drivers/dma/dw-edma/dw-hdma-v0-core.h | 17 ++
> drivers/dma/dw-edma/dw-hdma-v0-regs.h | 129 ++++++++++++
> include/linux/dma/edma.h | 3 +-
> 6 files changed, 431 insertions(+), 4 deletions(-)
> create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-core.c
> create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-core.h
> create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-regs.h
>
> diff --git a/drivers/dma/dw-edma/Makefile b/drivers/dma/dw-edma/Makefile
> index 8d45c0d5689d..b1c91ef2c63d 100644
> --- a/drivers/dma/dw-edma/Makefile
> +++ b/drivers/dma/dw-edma/Makefile
> @@ -2,6 +2,7 @@
>
> obj-$(CONFIG_DW_EDMA) += dw-edma.o
> dw-edma-$(CONFIG_DEBUG_FS) := dw-edma-v0-debugfs.o
> -dw-edma-objs := dw-edma-core.o \
> - dw-edma-v0-core.o $(dw-edma-y)
> +dw-edma-objs := dw-edma-core.o \
> + dw-edma-v0-core.o \
> + dw-hdma-v0-core.o $(dw-edma-y)
> obj-$(CONFIG_DW_EDMA_PCIE) += dw-edma-pcie.o
> diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
> index dc2908b66493..05c98b803a85 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-core.c
> @@ -18,6 +18,7 @@
>
> #include "dw-edma-core.h"
> #include "dw-edma-v0-core.h"
> +#include "dw-hdma-v0-core.h"
> #include "../dmaengine.h"
> #include "../virt-dma.h"
>
> @@ -923,7 +924,10 @@ int dw_edma_probe(struct dw_edma_chip *chip)
>
> dw->chip = chip;
>
> - dw_edma_v0_core_register(dw);
> + if (dw->chip->mf == EDMA_MF_HDMA_NATIVE)
> + dw_hdma_v0_core_register(dw);
> + else
> + dw_edma_v0_core_register(dw);
>
> raw_spin_lock_init(&dw->lock);
>
> diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> new file mode 100644
> index 000000000000..5446e9f38d65
> --- /dev/null
> +++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> @@ -0,0 +1,275 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2023 Cai Huoqing
> + * Synopsys DesignWare HDMA v0 core
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/irqreturn.h>
> +#include <linux/io-64-nonatomic-lo-hi.h>
> +
> +#include "dw-edma-core.h"
> +#include "dw-hdma-v0-core.h"
> +#include "dw-hdma-v0-regs.h"
> +
> +enum dw_hdma_control {
> + DW_HDMA_V0_CB = BIT(0),
> + DW_HDMA_V0_TCB = BIT(1),
> + DW_HDMA_V0_LLP = BIT(2),
> + DW_HDMA_V0_LIE = BIT(3),
> + DW_HDMA_V0_RIE = BIT(4),
> + DW_HDMA_V0_CCS = BIT(8),
> + DW_HDMA_V0_LLE = BIT(9),
> +};
> +
> +static inline struct dw_hdma_v0_regs __iomem *__dw_regs(struct dw_edma *dw)
> +{
> + return dw->chip->reg_base;
> +}
> +
> +static inline struct dw_hdma_v0_ch_regs __iomem *
> +__dw_ch_regs(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch)
> +{
> + if (dir == EDMA_DIR_WRITE)
> + return &(__dw_regs(dw)->ch[ch].wr);
> + else
> + return &(__dw_regs(dw)->ch[ch].rd);
> +}
> +
> +#define SET_CH_32(dw, dir, ch, name, value) \
> + writel(value, &(__dw_ch_regs(dw, dir, ch)->name))
> +
> +#define GET_CH_32(dw, dir, ch, name) \
> + readl(&(__dw_ch_regs(dw, dir, ch)->name))
> +
> +#define SET_BOTH_CH_32(dw, ch, name, value) \
> + do { \
> + writel(value, &(__dw_ch_regs(dw, EDMA_DIR_WRITE, ch)->name)); \
> + writel(value, &(__dw_ch_regs(dw, EDMA_DIR_READ, ch)->name)); \
> + } while (0)
> +
> +/* HDMA management callbacks */
> +static void dw_hdma_v0_core_off(struct dw_edma *dw)
> +{
> + int id;
> +
> + for (id = 0; id < HDMA_V0_MAX_NR_CH; id++) {
> + SET_BOTH_CH_32(dw, id, int_setup,
> + HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK);
> + SET_BOTH_CH_32(dw, id, int_clear,
> + HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK);
> + SET_BOTH_CH_32(dw, id, ch_en, 0);
> + }
> +}
> +
> +static u16 dw_hdma_v0_core_ch_count(struct dw_edma *dw, enum dw_edma_dir dir)
> +{
> + u32 num_ch = 0;
> + int id;
> +
> + for (id = 0; id < HDMA_V0_MAX_NR_CH; id++) {
> + if (GET_CH_32(dw, id, dir, ch_en) & BIT(0))
> + num_ch++;
> + }
> +
> + if (num_ch > HDMA_V0_MAX_NR_CH)
> + num_ch = HDMA_V0_MAX_NR_CH;
> +
> + return (u16)num_ch;
> +}
> +
> +static enum dma_status dw_hdma_v0_core_ch_status(struct dw_edma_chan *chan)
> +{
> + struct dw_edma *dw = chan->dw;
> + u32 tmp;
> +
> + tmp = FIELD_GET(HDMA_V0_CH_STATUS_MASK,
> + GET_CH_32(dw, chan->id, chan->dir, ch_stat));
> +
> + if (tmp == 1)
> + return DMA_IN_PROGRESS;
> + else if (tmp == 3)
> + return DMA_COMPLETE;
> + else
> + return DMA_ERROR;
> +}
> +

> +static
> +irqreturn_t dw_hdma_v0_core_handle_int(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir,
> + dw_edma_handler_t done, dw_edma_handler_t abort)

Please place the return value together with the modifier too:
+static irqreturn_t
+dw_hdma_v0_core_handle_int(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir,
+ dw_edma_handler_t done, dw_edma_handler_t abort)

as it's normally done in the driver for the non-inline methods.

> +{
> + struct dw_edma *dw = dw_irq->dw;
> + unsigned long total, pos, val;
> + irqreturn_t ret = IRQ_NONE;
> + struct dw_edma_chan *chan;
> + unsigned long off, mask;
> +
> + if (dir == EDMA_DIR_WRITE) {
> + total = dw->wr_ch_cnt;
> + off = 0;
> + mask = dw_irq->wr_mask;
> + } else {
> + total = dw->rd_ch_cnt;
> + off = dw->wr_ch_cnt;
> + mask = dw_irq->rd_mask;
> + }
> +
> + for_each_set_bit(pos, &mask, total) {
> + chan = &dw->chan[pos + off];
> +

> + val = GET_CH_32(dw, chan->dir, chan->id, int_stat);
> + if (FIELD_GET(HDMA_V0_STOP_INT_MASK, val)) {
> + SET_CH_32(dw, chan->dir, chan->id,
> + int_clear, HDMA_V0_STOP_INT_MASK);
> + done(chan);
> +
> + ret = IRQ_HANDLED;
> + }
> +
> + if (FIELD_GET(HDMA_V0_ABORT_INT_MASK, val)) {
> + SET_CH_32(dw, chan->dir, chan->id,
> + int_clear, HDMA_V0_ABORT_INT_MASK);

In v5 I was talking about the dw_hdma_v0_core_check_done_int() and
dw_hdma_v0_core_check_abort_int() methods only. They didn't imply any
CSR access but merely returned a field of the passed value. So
creating a separate function just for that seemed redundant. The rest
of the inliners (dw_hdma_v0_core_clear_done_int(),
dw_hdma_v0_core_clear_abort_int() and dw_hdma_v0_core_status_int())
looked ok to me.

> + abort(&dw->chan[pos + off]);

em, why not "abort(chan);" here?

-Serge(y)

> +
> + ret = IRQ_HANDLED;
> + }
> + }
> +
> + return ret;
> +}
> +
> +static void dw_hdma_v0_write_ll_data(struct dw_edma_chunk *chunk, int i,
> + u32 control, u32 size, u64 sar, u64 dar)
> +{
> + ptrdiff_t ofs = i * sizeof(struct dw_hdma_v0_lli);
> +
> + if (chunk->chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL) {
> + struct dw_hdma_v0_lli *lli = chunk->ll_region.vaddr.mem + ofs;
> +
> + lli->control = control;
> + lli->transfer_size = size;
> + lli->sar.reg = sar;
> + lli->dar.reg = dar;
> + } else {
> + struct dw_hdma_v0_lli __iomem *lli = chunk->ll_region.vaddr.io + ofs;
> +
> + writel(control, &lli->control);
> + writel(size, &lli->transfer_size);
> + writeq(sar, &lli->sar.reg);
> + writeq(dar, &lli->dar.reg);
> + }
> +}
> +
> +static void dw_hdma_v0_write_ll_link(struct dw_edma_chunk *chunk,
> + int i, u32 control, u64 pointer)
> +{
> + ptrdiff_t ofs = i * sizeof(struct dw_hdma_v0_lli);
> +
> + if (chunk->chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL) {
> + struct dw_hdma_v0_llp *llp = chunk->ll_region.vaddr.mem + ofs;
> +
> + llp->control = control;
> + llp->llp.reg = pointer;
> + } else {
> + struct dw_hdma_v0_llp __iomem *llp = chunk->ll_region.vaddr.io + ofs;
> +
> + writel(control, &llp->control);
> + writeq(pointer, &llp->llp.reg);
> + }
> +}
> +
> +static void dw_hdma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
> +{
> + struct dw_edma_burst *child;
> + struct dw_edma_chan *chan = chunk->chan;
> + u32 control = 0, i = 0;
> + int j;
> +
> + if (chunk->cb)
> + control = DW_HDMA_V0_CB;
> +
> + j = chunk->bursts_alloc;
> + list_for_each_entry(child, &chunk->burst->list, list) {
> + j--;
> + if (!j) {
> + control |= DW_HDMA_V0_LIE;
> + if (!(chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL))
> + control |= DW_HDMA_V0_RIE;
> + }
> +
> + dw_hdma_v0_write_ll_data(chunk, i++, control, child->sz,
> + child->sar, child->dar);
> + }
> +
> + control = DW_HDMA_V0_LLP | DW_HDMA_V0_TCB;
> + if (!chunk->cb)
> + control |= DW_HDMA_V0_CB;
> +
> + dw_hdma_v0_write_ll_link(chunk, i, control, chunk->ll_region.paddr);
> +}
> +
> +static void dw_hdma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
> +{
> + struct dw_edma_chan *chan = chunk->chan;
> + struct dw_edma *dw = chan->dw;
> + u32 tmp;
> +
> + dw_hdma_v0_core_write_chunk(chunk);
> +
> + if (first) {
> + /* Enable engine */
> + SET_CH_32(dw, chan->dir, chan->id, ch_en, BIT(0));
> + /* Interrupt enable&unmask - done, abort */
> + tmp = GET_CH_32(dw, chan->dir, chan->id, int_setup) |
> + HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK |
> + HDMA_V0_LOCAL_STOP_INT_EN | HDMA_V0_LOCAL_STOP_INT_EN;
> + SET_CH_32(dw, chan->dir, chan->id, int_setup, tmp);
> + /* Channel control */
> + SET_CH_32(dw, chan->dir, chan->id, control1, HDMA_V0_LINKLIST_EN);
> + /* Linked list */
> + /* llp is not aligned on 64bit -> keep 32bit accesses */
> + SET_CH_32(dw, chan->dir, chan->id, llp.lsb,
> + lower_32_bits(chunk->ll_region.paddr));
> + SET_CH_32(dw, chan->dir, chan->id, llp.msb,
> + upper_32_bits(chunk->ll_region.paddr));
> + }
> + /* Set consumer cycle */
> + SET_CH_32(dw, chan->dir, chan->id, cycle_sync,
> + HDMA_V0_CONSUMER_CYCLE_STAT | HDMA_V0_CONSUMER_CYCLE_BIT);
> + /* Doorbell */
> + SET_CH_32(dw, chan->dir, chan->id, doorbell, HDMA_V0_DOORBELL_START);
> +}
> +
> +static void dw_hdma_v0_core_ch_config(struct dw_edma_chan *chan)
> +{
> + struct dw_edma *dw = chan->dw;
> +
> + /* MSI done addr - low, high */
> + SET_CH_32(dw, chan->dir, chan->id, msi_stop.lsb, chan->msi.address_lo);
> + SET_CH_32(dw, chan->dir, chan->id, msi_stop.msb, chan->msi.address_hi);
> + /* MSI abort addr - low, high */
> + SET_CH_32(dw, chan->dir, chan->id, msi_abort.lsb, chan->msi.address_lo);
> + SET_CH_32(dw, chan->dir, chan->id, msi_abort.msb, chan->msi.address_hi);
> + /* config MSI data */
> + SET_CH_32(dw, chan->dir, chan->id, msi_msgdata, chan->msi.data);
> +}
> +
> +/* HDMA debugfs callbacks */
> +static void dw_hdma_v0_core_debugfs_on(struct dw_edma *dw)
> +{
> +}
> +
> +static const struct dw_edma_core_ops dw_hdma_v0_core = {
> + .off = dw_hdma_v0_core_off,
> + .ch_count = dw_hdma_v0_core_ch_count,
> + .ch_status = dw_hdma_v0_core_ch_status,
> + .handle_int = dw_hdma_v0_core_handle_int,
> + .start = dw_hdma_v0_core_start,
> + .ch_config = dw_hdma_v0_core_ch_config,
> + .debugfs_on = dw_hdma_v0_core_debugfs_on,
> +};
> +
> +void dw_hdma_v0_core_register(struct dw_edma *dw)
> +{
> + dw->core = &dw_hdma_v0_core;
> +}
> diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.h b/drivers/dma/dw-edma/dw-hdma-v0-core.h
> new file mode 100644
> index 000000000000..c373b4f0bd8a
> --- /dev/null
> +++ b/drivers/dma/dw-edma/dw-hdma-v0-core.h
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2023 Cai Huoqing
> + * Synopsys DesignWare HDMA v0 core
> + *
> + * Author: Cai Huoqing <cai.huoqing@xxxxxxxxx>
> + */
> +
> +#ifndef _DW_HDMA_V0_CORE_H
> +#define _DW_HDMA_V0_CORE_H
> +
> +#include <linux/dma/edma.h>
> +
> +/* HDMA core register */
> +void dw_hdma_v0_core_register(struct dw_edma *dw);
> +
> +#endif /* _DW_HDMA_V0_CORE_H */
> diff --git a/drivers/dma/dw-edma/dw-hdma-v0-regs.h b/drivers/dma/dw-edma/dw-hdma-v0-regs.h
> new file mode 100644
> index 000000000000..1106f56280c0
> --- /dev/null
> +++ b/drivers/dma/dw-edma/dw-hdma-v0-regs.h
> @@ -0,0 +1,129 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2023 Cai Huoqing
> + * Synopsys DesignWare HDMA v0 reg
> + *
> + * Author: Cai Huoqing <cai.huoqing@xxxxxxxxx>
> + */
> +
> +#ifndef _DW_HDMA_V0_REGS_H
> +#define _DW_HDMA_V0_REGS_H
> +
> +#include <linux/dmaengine.h>
> +
> +#define HDMA_V0_MAX_NR_CH 8
> +#define HDMA_V0_LOCAL_ABORT_INT_EN BIT(6)
> +#define HDMA_V0_REMOTE_ABORT_INT_EN BIT(5)
> +#define HDMA_V0_LOCAL_STOP_INT_EN BIT(4)
> +#define HDMA_V0_REMOTEL_STOP_INT_EN BIT(3)
> +#define HDMA_V0_ABORT_INT_MASK BIT(2)
> +#define HDMA_V0_STOP_INT_MASK BIT(0)
> +#define HDMA_V0_LINKLIST_EN BIT(0)
> +#define HDMA_V0_CONSUMER_CYCLE_STAT BIT(1)
> +#define HDMA_V0_CONSUMER_CYCLE_BIT BIT(0)
> +#define HDMA_V0_DOORBELL_START BIT(0)
> +#define HDMA_V0_CH_STATUS_MASK GENMASK(1, 0)
> +
> +struct dw_hdma_v0_ch_regs {
> + u32 ch_en; /* 0x0000 */
> + u32 doorbell; /* 0x0004 */
> + u32 prefetch; /* 0x0008 */
> + u32 handshake; /* 0x000c */
> + union {
> + u64 reg; /* 0x0010..0x0014 */
> + struct {
> + u32 lsb; /* 0x0010 */
> + u32 msb; /* 0x0014 */
> + };
> + } llp;
> + u32 cycle_sync; /* 0x0018 */
> + u32 transfer_size; /* 0x001c */
> + union {
> + u64 reg; /* 0x0020..0x0024 */
> + struct {
> + u32 lsb; /* 0x0020 */
> + u32 msb; /* 0x0024 */
> + };
> + } sar;
> + union {
> + u64 reg; /* 0x0028..0x002c */
> + struct {
> + u32 lsb; /* 0x0028 */
> + u32 msb; /* 0x002c */
> + };
> + } dar;
> +
> + u32 watermark_en; /* 0x0030 */
> + u32 control1; /* 0x0034 */
> + u32 func_num; /* 0x0038 */
> + u32 qos; /* 0x003c */
> + u64 reserved[8]; /* 0x0040..0x0078 */
> + u32 ch_stat; /* 0x0080 */
> + u32 int_stat; /* 0x0084 */
> + u32 int_setup; /* 0x0088 */
> + u32 int_clear; /* 0x008c */
> + union {
> + u64 reg; /* 0x0090..0x0094 */
> + struct {
> + u32 lsb; /* 0x0090 */
> + u32 msb; /* 0x0094 */
> + };
> + } msi_stop;
> + union {
> + u64 reg; /* 0x0098..0x009c */
> + struct {
> + u32 lsb; /* 0x0098 */
> + u32 msb; /* 0x009c */
> + };
> + } msi_watermark;
> + union {
> + u64 reg; /* 0x00a0..0x00a4 */
> + struct {
> + u32 lsb; /* 0x00a0 */
> + u32 msb; /* 0x00a4 */
> + };
> + } msi_abort;
> + u32 msi_msgdata; /* 0x00a8 */
> +} __packed;
> +
> +struct dw_hdma_v0_ch {
> + struct dw_hdma_v0_ch_regs wr; /* 0x0000 */
> + struct dw_hdma_v0_ch_regs rd; /* 0x0100 */
> +} __packed;
> +
> +struct dw_hdma_v0_regs {
> + struct dw_hdma_v0_ch ch[HDMA_V0_MAX_NR_CH]; /* 0x0000..0x0fa8 */
> +} __packed;
> +
> +struct dw_hdma_v0_lli {
> + u32 control;
> + u32 transfer_size;
> + union {
> + u64 reg;
> + struct {
> + u32 lsb;
> + u32 msb;
> + };
> + } sar;
> + union {
> + u64 reg;
> + struct {
> + u32 lsb;
> + u32 msb;
> + };
> + } dar;
> +} __packed;
> +
> +struct dw_hdma_v0_llp {
> + u32 control;
> + u32 reserved;
> + union {
> + u64 reg;
> + struct {
> + u32 lsb;
> + u32 msb;
> + };
> + } llp;
> +} __packed;
> +
> +#endif /* _DW_HDMA_V0_REGS_H */
> diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
> index ed401c965a87..3080747689f6 100644
> --- a/include/linux/dma/edma.h
> +++ b/include/linux/dma/edma.h
> @@ -48,7 +48,8 @@ struct dw_edma_plat_ops {
> enum dw_edma_map_format {
> EDMA_MF_EDMA_LEGACY = 0x0,
> EDMA_MF_EDMA_UNROLL = 0x1,
> - EDMA_MF_HDMA_COMPAT = 0x5
> + EDMA_MF_HDMA_COMPAT = 0x5,
> + EDMA_MF_HDMA_NATIVE = 0x7,
> };
>
> /**
> --
> 2.34.1
>