Re: [PATCH v7 4/5] dmaengine: dw-edma: Add HDMA DebugFS support

From: Serge Semin
Date: Wed Mar 22 2023 - 01:44:16 EST


On Wed, Mar 22, 2023 at 11:17:55AM +0800, Cai Huoqing wrote:
> On 20 3月 23 14:53:23, Serge Semin wrote:
> > On Wed, Mar 15, 2023 at 09:28:35AM +0800, Cai Huoqing wrote:
> > > From: Cai huoqing <cai.huoqing@xxxxxxxxx>
> > >
> > > Add HDMA DebugFS support to show register information
> > >
> > > Signed-off-by: Cai huoqing <cai.huoqing@xxxxxxxxx>
> > > ---
> > > v6->v7:
> > > 1.Move the change of register file from patch[4/5] to patch[3/5].
> > > v6 link:
> > > https://lore.kernel.org/lkml/20230310032342.17395-5-cai.huoqing@xxxxxxxxx/
> > >
> > > drivers/dma/dw-edma/Makefile | 3 +-
> > > drivers/dma/dw-edma/dw-hdma-v0-core.c | 2 +
> > > drivers/dma/dw-edma/dw-hdma-v0-debugfs.c | 176 +++++++++++++++++++++++
> > > drivers/dma/dw-edma/dw-hdma-v0-debugfs.h | 22 +++
> > > 4 files changed, 202 insertions(+), 1 deletion(-)
> > > create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-debugfs.c
> > > create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-debugfs.h
> > >
> > > diff --git a/drivers/dma/dw-edma/Makefile b/drivers/dma/dw-edma/Makefile
> > > index b1c91ef2c63d..83ab58f87760 100644
> > > --- a/drivers/dma/dw-edma/Makefile
> > > +++ b/drivers/dma/dw-edma/Makefile
> > > @@ -1,7 +1,8 @@
> > > # SPDX-License-Identifier: GPL-2.0
> > >
> > > obj-$(CONFIG_DW_EDMA) += dw-edma.o
> > > -dw-edma-$(CONFIG_DEBUG_FS) := dw-edma-v0-debugfs.o
> > > +dw-edma-$(CONFIG_DEBUG_FS) := dw-edma-v0-debugfs.o \
> > > + dw-hdma-v0-debugfs.o
> > > dw-edma-objs := dw-edma-core.o \
> > > dw-edma-v0-core.o \
> > > dw-hdma-v0-core.o $(dw-edma-y)
> > > diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> > > index cf274231cda9..b540c9ad7dfb 100644
> > > --- a/drivers/dma/dw-edma/dw-hdma-v0-core.c
> > > +++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> > > @@ -11,6 +11,7 @@
> > > #include "dw-edma-core.h"
> > > #include "dw-hdma-v0-core.h"
> > > #include "dw-hdma-v0-regs.h"
> > > +#include "dw-hdma-v0-debugfs.h"
> > >
> > > enum dw_hdma_control {
> > > DW_HDMA_V0_CB = BIT(0),
> > > @@ -257,6 +258,7 @@ static void dw_hdma_v0_core_ch_config(struct dw_edma_chan *chan)
> > > /* HDMA debugfs callbacks */
> > > static void dw_hdma_v0_core_debugfs_on(struct dw_edma *dw)
> > > {
> > > + dw_hdma_v0_debugfs_on(dw);
> > > }
> > >
> > > static const struct dw_edma_core_ops dw_hdma_v0_core = {
> > > diff --git a/drivers/dma/dw-edma/dw-hdma-v0-debugfs.c b/drivers/dma/dw-edma/dw-hdma-v0-debugfs.c
> > > new file mode 100644
> > > index 000000000000..f2082b1bf72a
> > > --- /dev/null
> > > +++ b/drivers/dma/dw-edma/dw-hdma-v0-debugfs.c
> > > @@ -0,0 +1,176 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Copyright (c) 2023 Cai Huoqing
> > > + * Synopsys DesignWare HDMA v0 debugfs
> > > + *
> > > + * Author: Cai Huoqing <cai.huoqing@xxxxxxxxx>
> > > + */
> > > +
> > > +#include <linux/debugfs.h>
> > > +#include <linux/bitfield.h>
> > > +
> > > +#include "dw-hdma-v0-debugfs.h"
> > > +#include "dw-hdma-v0-regs.h"
> > > +#include "dw-edma-core.h"
> > > +
> > > +#define REGS_ADDR(dw, name) \
> > > + ({ \
> > > + struct dw_hdma_v0_regs __iomem *__regs = (dw)->chip->reg_base; \
> > > + \
> > > + (void __iomem *)&__regs->name; \
> > > + })
> > > +
> > > +#define REGS_CH_ADDR(dw, name, _dir, _ch) \
> > > + ({ \
> > > + struct dw_hdma_v0_ch_regs __iomem *__ch_regs; \
> > > + \
> > > + if (_dir == EDMA_DIR_READ) \
> > > + __ch_regs = REGS_ADDR(dw, ch[_ch].rd); \
> > > + else \
> > > + __ch_regs = REGS_ADDR(dw, ch[_ch].wr); \
> > > + \
> > > + (void __iomem *)&__ch_regs->name; \
> > > + })
> > > +
> > > +#define CTX_REGISTER(dw, name, dir, ch) \
> > > + { dw, #name, REGS_CH_ADDR(dw, name, dir, ch), dir, ch }
> > > +
> > > +#define REGISTER(dw, name) \
> > > + { dw, #name, REGS_ADDR(dw, name) }
> > > +
> > > +#define WRITE_STR "write"
> > > +#define READ_STR "read"
> > > +#define CHANNEL_STR "channel"
> > > +#define REGISTERS_STR "registers"
> > > +
> > > +struct dw_hdma_debugfs_entry {
> > > + struct dw_edma *dw;
> > > + const char *name;
> > > + void __iomem *reg;
> >
> > > + enum dw_edma_dir dir;
> > > + u16 ch;
> >
> > Fields above seems like unused. What about dropping them?
> > * Note the CTX_REGISTER() initializer will need to be fixed too.
>

> Do you mean that,
>
> CTX_REGISTER() like this
>
> +#define CTX_REGISTER(dw, name, dir, ch) \
> + {#name, REGS_CH_ADDR(dw, name, dir, ch)}
>
> dw_hdma_debug_debugfs_entry will be changed to
>
> +struct dw_hdma_debugfs_entry {
> + const char *name;
> + void __iomem *reg;
> +};
>
> right?

Yes.

-Serge(y)

>
> Thanks,
> -Cai
> >
> > BTW it doesn't seem like HDMA will ever need the fields above, does it?
> > In case of DW eDMA they were necessary to perform the viewport-based
> > access of the CSR. AFAICS HDMA has always unrolled CSRs mapping.
> > Am I right?
> >
> > Other than that looks good.
> >
> > -Serge(y)
> >
> > > +};
> > > +
> > > +static int dw_hdma_debugfs_u32_get(void *data, u64 *val)
> > > +{
> > > + struct dw_hdma_debugfs_entry *entry = data;
> > > + void __iomem *reg = entry->reg;
> > > +
> > > + *val = readl(reg);
> > > +
> > > + return 0;
> > > +}
> > > +DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, dw_hdma_debugfs_u32_get, NULL, "0x%08llx\n");
> > > +
> > > +static void dw_hdma_debugfs_create_x32(struct dw_edma *dw,
> > > + const struct dw_hdma_debugfs_entry ini[],
> > > + int nr_entries, struct dentry *dent)
> > > +{
> > > + struct dw_hdma_debugfs_entry *entries;
> > > + int i;
> > > +
> > > + entries = devm_kcalloc(dw->chip->dev, nr_entries, sizeof(*entries),
> > > + GFP_KERNEL);
> > > + if (!entries)
> > > + return;
> > > +
> > > + for (i = 0; i < nr_entries; i++) {
> > > + entries[i] = ini[i];
> > > +
> > > + debugfs_create_file_unsafe(entries[i].name, 0444, dent,
> > > + &entries[i], &fops_x32);
> > > + }
> > > +}
> > > +
> > > +static void dw_hdma_debugfs_regs_ch(struct dw_edma *dw, enum dw_edma_dir dir,
> > > + u16 ch, struct dentry *dent)
> > > +{
> > > + const struct dw_hdma_debugfs_entry debugfs_regs[] = {
> > > + CTX_REGISTER(dw, ch_en, dir, ch),
> > > + CTX_REGISTER(dw, doorbell, dir, ch),
> > > + CTX_REGISTER(dw, prefetch, dir, ch),
> > > + CTX_REGISTER(dw, handshake, dir, ch),
> > > + CTX_REGISTER(dw, llp.lsb, dir, ch),
> > > + CTX_REGISTER(dw, llp.msb, dir, ch),
> > > + CTX_REGISTER(dw, cycle_sync, dir, ch),
> > > + CTX_REGISTER(dw, transfer_size, dir, ch),
> > > + CTX_REGISTER(dw, sar.lsb, dir, ch),
> > > + CTX_REGISTER(dw, sar.msb, dir, ch),
> > > + CTX_REGISTER(dw, dar.lsb, dir, ch),
> > > + CTX_REGISTER(dw, dar.msb, dir, ch),
> > > + CTX_REGISTER(dw, watermark_en, dir, ch),
> > > + CTX_REGISTER(dw, control1, dir, ch),
> > > + CTX_REGISTER(dw, func_num, dir, ch),
> > > + CTX_REGISTER(dw, qos, dir, ch),
> > > + CTX_REGISTER(dw, ch_stat, dir, ch),
> > > + CTX_REGISTER(dw, int_stat, dir, ch),
> > > + CTX_REGISTER(dw, int_setup, dir, ch),
> > > + CTX_REGISTER(dw, int_clear, dir, ch),
> > > + CTX_REGISTER(dw, msi_stop.lsb, dir, ch),
> > > + CTX_REGISTER(dw, msi_stop.msb, dir, ch),
> > > + CTX_REGISTER(dw, msi_watermark.lsb, dir, ch),
> > > + CTX_REGISTER(dw, msi_watermark.msb, dir, ch),
> > > + CTX_REGISTER(dw, msi_abort.lsb, dir, ch),
> > > + CTX_REGISTER(dw, msi_abort.msb, dir, ch),
> > > + CTX_REGISTER(dw, msi_msgdata, dir, ch),
> > > + };
> > > + int nr_entries = ARRAY_SIZE(debugfs_regs);
> > > +
> > > + dw_hdma_debugfs_create_x32(dw, debugfs_regs, nr_entries, dent);
> > > +}
> > > +
> > > +static void dw_hdma_debugfs_regs_wr(struct dw_edma *dw, struct dentry *dent)
> > > +{
> > > + struct dentry *regs_dent, *ch_dent;
> > > + char name[16];
> > > + int i;
> > > +
> > > + regs_dent = debugfs_create_dir(WRITE_STR, dent);
> > > +
> > > + for (i = 0; i < dw->wr_ch_cnt; i++) {
> > > + snprintf(name, sizeof(name), "%s:%d", CHANNEL_STR, i);
> > > +
> > > + ch_dent = debugfs_create_dir(name, regs_dent);
> > > +
> > > + dw_hdma_debugfs_regs_ch(dw, EDMA_DIR_WRITE, i, ch_dent);
> > > + }
> > > +}
> > > +
> > > +static void dw_hdma_debugfs_regs_rd(struct dw_edma *dw, struct dentry *dent)
> > > +{
> > > + struct dentry *regs_dent, *ch_dent;
> > > + char name[16];
> > > + int i;
> > > +
> > > + regs_dent = debugfs_create_dir(READ_STR, dent);
> > > +
> > > + for (i = 0; i < dw->rd_ch_cnt; i++) {
> > > + snprintf(name, sizeof(name), "%s:%d", CHANNEL_STR, i);
> > > +
> > > + ch_dent = debugfs_create_dir(name, regs_dent);
> > > +
> > > + dw_hdma_debugfs_regs_ch(dw, EDMA_DIR_READ, i, ch_dent);
> > > + }
> > > +}
> > > +
> > > +static void dw_hdma_debugfs_regs(struct dw_edma *dw)
> > > +{
> > > + struct dentry *regs_dent;
> > > +
> > > + regs_dent = debugfs_create_dir(REGISTERS_STR, dw->dma.dbg_dev_root);
> > > +
> > > + dw_hdma_debugfs_regs_wr(dw, regs_dent);
> > > + dw_hdma_debugfs_regs_rd(dw, regs_dent);
> > > +}
> > > +
> > > +void dw_hdma_v0_debugfs_on(struct dw_edma *dw)
> > > +{
> > > + if (!debugfs_initialized())
> > > + return;
> > > +
> > > + debugfs_create_u32("mf", 0444, dw->dma.dbg_dev_root, &dw->chip->mf);
> > > + debugfs_create_u16("wr_ch_cnt", 0444, dw->dma.dbg_dev_root, &dw->wr_ch_cnt);
> > > + debugfs_create_u16("rd_ch_cnt", 0444, dw->dma.dbg_dev_root, &dw->rd_ch_cnt);
> > > +
> > > + dw_hdma_debugfs_regs(dw);
> > > +}
> > > diff --git a/drivers/dma/dw-edma/dw-hdma-v0-debugfs.h b/drivers/dma/dw-edma/dw-hdma-v0-debugfs.h
> > > new file mode 100644
> > > index 000000000000..e6842c83777d
> > > --- /dev/null
> > > +++ b/drivers/dma/dw-edma/dw-hdma-v0-debugfs.h
> > > @@ -0,0 +1,22 @@
> > > +/* SPDX-License-Identifier: GPL-2.0 */
> > > +/*
> > > + * Copyright (c) 2023 Cai Huoqing
> > > + * Synopsys DesignWare HDMA v0 debugfs
> > > + *
> > > + * Author: Cai Huoqing <cai.huoqing@xxxxxxxxx>
> > > + */
> > > +
> > > +#ifndef _DW_HDMA_V0_DEBUG_FS_H
> > > +#define _DW_HDMA_V0_DEBUG_FS_H
> > > +
> > > +#include <linux/dma/edma.h>
> > > +
> > > +#ifdef CONFIG_DEBUG_FS
> > > +void dw_hdma_v0_debugfs_on(struct dw_edma *dw);
> > > +#else
> > > +static inline void dw_hdma_v0_debugfs_on(struct dw_edma *dw)
> > > +{
> > > +}
> > > +#endif /* CONFIG_DEBUG_FS */
> > > +
> > > +#endif /* _DW_HDMA_V0_DEBUG_FS_H */
> > > --
> > > 2.34.1
> > >