Date:   Thu, 16 Feb 2023 19:38:31 +0300
From:   Serge Semin <fancer.lancer@gmail.com>
To:     Cai Huoqing <cai.huoqing@linux.dev>
Cc:     Sergey.Semin@baikalelectronics.ru,
        Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
        Vinod Koul <vkoul@kernel.org>,
        Jingoo Han <jingoohan1@gmail.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>,
        Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org,
        linux-pci@vger.kernel.org
Subject: Re: [PATCH v3 3/4] dmaengine: dw-edma: Add support for native HDMA
Message-ID: <20230216163831.6lp3ywnz6pacncgg@mobilestation>
References: <20230213132411.65524-1-cai.huoqing@linux.dev>
 <20230213132411.65524-4-cai.huoqing@linux.dev>
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In-Reply-To: <20230213132411.65524-4-cai.huoqing@linux.dev>
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On Mon, Feb 13, 2023 at 09:24:08PM +0800, Cai Huoqing wrote:
> From: Cai huoqing <cai.huoqing@linux.dev>
> 
> 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 alignmented to byte.
> 
> Signed-off-by: Cai huoqing <cai.huoqing@linux.dev>
> ---
>  drivers/dma/dw-edma/Makefile          |   5 +-
>  drivers/dma/dw-edma/dw-hdma-v0-core.c | 315 ++++++++++++++++++++++++++
>  drivers/dma/dw-edma/dw-hdma-v0-core.h |  17 ++
>  drivers/dma/dw-edma/dw-hdma-v0-regs.h | 129 +++++++++++
>  4 files changed, 464 insertions(+), 2 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-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> new file mode 100644
> index 000000000000..7e4f98987e29
> --- /dev/null
> +++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> @@ -0,0 +1,315 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2023 Cai Huoqing
> + * Synopsys DesignWare HDMA v0 core
> + */
> +
> +#include <linux/bitfield.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 void dw_hdma_v0_core_clear_done_int(struct dw_edma_chan *chan)
> +{
> +	struct dw_edma *dw = chan->dw;
> +
> +	SET_CH_32(dw, chan->dir, chan->id, int_clear, HDMA_V0_STOP_INT_MASK);
> +}
> +
> +static void dw_hdma_v0_core_clear_abort_int(struct dw_edma_chan *chan)
> +{
> +	struct dw_edma *dw = chan->dw;
> +
> +	SET_CH_32(dw, chan->dir, chan->id, int_clear, HDMA_V0_ABORT_INT_MASK);
> +}
> +
> +static u32 dw_hdma_v0_core_status_int(struct dw_edma_chan *chan)
> +{
> +	struct dw_edma *dw = chan->dw;
> +
> +	return GET_CH_32(dw, chan->dir, chan->id, int_stat);
> +}
> +
> +static u32 dw_hdma_v0_core_check_done_int(u32 val)
> +{
> +	return FIELD_GET(HDMA_V0_STOP_INT_MASK, val);
> +}
> +
> +static u32 dw_hdma_v0_core_check_abort_int(u32 val)
> +{
> +	return FIELD_GET(HDMA_V0_ABORT_INT_MASK, val);
> +}
> +

> +static
> +void dw_hdma_v0_core_done_handle(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir)
> +{
> +	struct dw_edma *dw = dw_irq->dw;
> +	unsigned long total, pos, val;
> +	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) {
> +		struct dw_edma_chan *chan = &dw->chan[pos + off];
> +
> +		val = dw_hdma_v0_core_status_int(chan);
> +		if (dw_hdma_v0_core_check_done_int(val))
> +			dw_edma_done_interrupt(chan);
> +	}
> +}
> +
> +static
> +void dw_hdma_v0_core_abort_handle(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir)
> +{
> +	struct dw_edma *dw = dw_irq->dw;
> +	unsigned long total, pos, val;
> +	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) {
> +		struct dw_edma_chan *chan = &dw->chan[pos + off];
> +
> +		val = dw_hdma_v0_core_status_int(chan);
> +		if (dw_hdma_v0_core_check_abort_int(val))
> +			dw_edma_abort_interrupt(&dw->chan[pos + off]);
> +	}
> +}

Please see my comments to the previous patch in the series regarding
the done/abort IRQ-handlers and the core_clear_{done,abort}_int
callbacks usage.

> +
> +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 hdma_core = {
> +	.off = dw_hdma_v0_core_off,
> +	.ch_count = dw_hdma_v0_core_ch_count,
> +	.ch_status = dw_hdma_v0_core_ch_status,
> +	.clear_done_int = dw_hdma_v0_core_clear_done_int,
> +	.clear_abort_int = dw_hdma_v0_core_clear_abort_int,
> +	.done_handle = dw_hdma_v0_core_done_handle,
> +	.abort_handle = dw_hdma_v0_core_abort_handle,
> +	.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 = &hdma_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@linux.dev>
> + */
> +
> +#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..f6b2bd03060c
> --- /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@linux.dev>
> + */
> +
> +#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 */
> +	u32	reserved;			/* 0x0040..0x007c */

As Bjorn correctly noted, please fix the indentation.

> +	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 */

ditto

-Serge(y)

> +} __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 */
> -- 
> 2.34.1
>