Re: [PATCH v5 2/4] dmaengine: dw-edma: Create a new dw_edma_core_ops structure to abstract controller operation

From: Serge Semin
Date: Fri Mar 03 2023 - 12:15:12 EST


On Fri, Mar 03, 2023 at 08:09:38PM +0300, Serge Semin wrote:
> On Fri, Mar 03, 2023 at 08:46:32PM +0800, Cai Huoqing wrote:
> > From: Cai huoqing <cai.huoqing@xxxxxxxxx>
> >
> > The structure dw_edma_core_ops has a set of the pointers
> > abstracting out the DW eDMA vX and DW HDMA Native controllers.
> > And use dw_edma_v0_core_register to set up operation.
> >
> > Signed-off-by: Cai huoqing <cai.huoqing@xxxxxxxxx>
> > ---
> > v4->v5:
> > 1.Refactor add return irqreturn_t to dw_edma_core_handle_int
> > 2.Define dw_edma_core_handle_int as inline fuction and move to
> > dw-edma-core.h.
> >
> > v4 link:
> > https://lore.kernel.org/lkml/20230221034656.14476-3-cai.huoqing@xxxxxxxxx/
> >
> > drivers/dma/dw-edma/dw-edma-core.c | 83 ++++++++-------------------
> > drivers/dma/dw-edma/dw-edma-core.h | 64 +++++++++++++++++++++
> > drivers/dma/dw-edma/dw-edma-v0-core.c | 75 ++++++++++++++++++++----
> > drivers/dma/dw-edma/dw-edma-v0-core.h | 14 +----
> > 4 files changed, 153 insertions(+), 83 deletions(-)
> >
> > diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
> > index 1906a836f0aa..5cfba5730695 100644
> > --- a/drivers/dma/dw-edma/dw-edma-core.c
> > +++ b/drivers/dma/dw-edma/dw-edma-core.c
> > @@ -183,6 +183,7 @@ static void vchan_free_desc(struct virt_dma_desc *vdesc)
> >
> > static void dw_edma_start_transfer(struct dw_edma_chan *chan)
> > {
> > + struct dw_edma *dw = chan->dw;
> > struct dw_edma_chunk *child;
> > struct dw_edma_desc *desc;
> > struct virt_dma_desc *vd;
> > @@ -200,7 +201,7 @@ static void dw_edma_start_transfer(struct dw_edma_chan *chan)
> > if (!child)
> > return;
> >
> > - dw_edma_v0_core_start(child, !desc->xfer_sz);
> > + dw_edma_core_start(dw, child, !desc->xfer_sz);
> > desc->xfer_sz += child->ll_region.sz;
> > dw_edma_free_burst(child);
> > list_del(&child->list);
> > @@ -285,7 +286,7 @@ static int dw_edma_device_terminate_all(struct dma_chan *dchan)
> > chan->configured = false;
> > } else if (chan->status == EDMA_ST_IDLE) {
> > chan->configured = false;
> > - } else if (dw_edma_v0_core_ch_status(chan) == DMA_COMPLETE) {
> > + } else if (dw_edma_core_ch_status(chan) == DMA_COMPLETE) {
> > /*
> > * The channel is in a false BUSY state, probably didn't
> > * receive or lost an interrupt
> > @@ -588,14 +589,12 @@ dw_edma_device_prep_interleaved_dma(struct dma_chan *dchan,
> > return dw_edma_device_transfer(&xfer);
> > }
> >
> > -static void dw_edma_done_interrupt(struct dw_edma_chan *chan)
> > +void dw_edma_done_interrupt(struct dw_edma_chan *chan)
> > {
> > struct dw_edma_desc *desc;
> > struct virt_dma_desc *vd;
> > unsigned long flags;
> >
> > - dw_edma_v0_core_clear_done_int(chan);
> > -
> > spin_lock_irqsave(&chan->vc.lock, flags);
> > vd = vchan_next_desc(&chan->vc);
> > if (vd) {
> > @@ -631,13 +630,11 @@ static void dw_edma_done_interrupt(struct dw_edma_chan *chan)
> > spin_unlock_irqrestore(&chan->vc.lock, flags);
> > }
> >
> > -static void dw_edma_abort_interrupt(struct dw_edma_chan *chan)
> > +void dw_edma_abort_interrupt(struct dw_edma_chan *chan)
> > {
> > struct virt_dma_desc *vd;
> > unsigned long flags;
> >
> > - dw_edma_v0_core_clear_abort_int(chan);
> > -
> > spin_lock_irqsave(&chan->vc.lock, flags);
> > vd = vchan_next_desc(&chan->vc);
> > if (vd) {
> > @@ -649,63 +646,29 @@ static void dw_edma_abort_interrupt(struct dw_edma_chan *chan)
> > chan->status = EDMA_ST_IDLE;
> > }
> >
> > -static irqreturn_t dw_edma_interrupt(int irq, void *data, bool write)
> > +static inline irqreturn_t dw_edma_interrupt_write(int irq, void *data)
> > {
> > struct dw_edma_irq *dw_irq = data;
> > - struct dw_edma *dw = dw_irq->dw;
> > - unsigned long total, pos, val;
> > - unsigned long off;
> > - u32 mask;
> > -
> > - if (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;
> > - }
> > -
> > - val = dw_edma_v0_core_status_done_int(dw, write ?
> > - EDMA_DIR_WRITE :
> > - EDMA_DIR_READ);
> > - val &= mask;
> > - for_each_set_bit(pos, &val, total) {
> > - struct dw_edma_chan *chan = &dw->chan[pos + off];
> > -
> > - dw_edma_done_interrupt(chan);
> > - }
> > -
> > - val = dw_edma_v0_core_status_abort_int(dw, write ?
> > - EDMA_DIR_WRITE :
> > - EDMA_DIR_READ);
> > - val &= mask;
> > - for_each_set_bit(pos, &val, total) {
> > - struct dw_edma_chan *chan = &dw->chan[pos + off];
> > -
> > - dw_edma_abort_interrupt(chan);
> > - }
> >
> > - return IRQ_HANDLED;
> > -}
> > -
> > -static inline irqreturn_t dw_edma_interrupt_write(int irq, void *data)
> > -{
> > - return dw_edma_interrupt(irq, data, true);
> > + return dw_edma_core_handle_int(dw_irq, EDMA_DIR_WRITE);
> > }
> >
> > static inline irqreturn_t dw_edma_interrupt_read(int irq, void *data)
> > {
> > - return dw_edma_interrupt(irq, data, false);
> > + struct dw_edma_irq *dw_irq = data;
> > +
> > + return dw_edma_core_handle_int(dw_irq, EDMA_DIR_READ);
> > }
> >
> > static irqreturn_t dw_edma_interrupt_common(int irq, void *data)
> > {
> > - dw_edma_interrupt(irq, data, true);
> > - dw_edma_interrupt(irq, data, false);
> > + struct dw_edma_irq *dw_irq = data;
> > + irqreturn_t ret = IRQ_NONE;
> > +
> > + ret |= dw_edma_core_handle_int(dw_irq, EDMA_DIR_WRITE);
> > + ret |= dw_edma_core_handle_int(dw_irq, EDMA_DIR_READ);
> >
> > - return IRQ_HANDLED;
> > + return ret;
> > }
> >
> > static int dw_edma_alloc_chan_resources(struct dma_chan *dchan)
> > @@ -806,7 +769,7 @@ static int dw_edma_channel_setup(struct dw_edma *dw, u32 wr_alloc, u32 rd_alloc)
> >
> > vchan_init(&chan->vc, dma);
> >
> > - dw_edma_v0_core_device_config(chan);
> > + dw_edma_core_ch_config(chan);
> > }
> >
> > /* Set DMA channel capabilities */
> > @@ -951,14 +914,16 @@ int dw_edma_probe(struct dw_edma_chip *chip)
> >
> > dw->chip = chip;
> >
> > + dw_edma_v0_core_register(dw);
> > +
> > raw_spin_lock_init(&dw->lock);
> >
> > dw->wr_ch_cnt = min_t(u16, chip->ll_wr_cnt,
> > - dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE));
> > + dw_edma_core_ch_count(dw, EDMA_DIR_WRITE));
> > dw->wr_ch_cnt = min_t(u16, dw->wr_ch_cnt, EDMA_MAX_WR_CH);
> >
> > dw->rd_ch_cnt = min_t(u16, chip->ll_rd_cnt,
> > - dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ));
> > + dw_edma_core_ch_count(dw, EDMA_DIR_READ));
> > dw->rd_ch_cnt = min_t(u16, dw->rd_ch_cnt, EDMA_MAX_RD_CH);
> >
> > if (!dw->wr_ch_cnt && !dw->rd_ch_cnt)
> > @@ -977,7 +942,7 @@ int dw_edma_probe(struct dw_edma_chip *chip)
> > dev_name(chip->dev));
> >
> > /* Disable eDMA, only to establish the ideal initial conditions */
> > - dw_edma_v0_core_off(dw);
> > + dw_edma_core_off(dw);
> >
> > /* Request IRQs */
> > err = dw_edma_irq_request(dw, &wr_alloc, &rd_alloc);
> > @@ -990,7 +955,7 @@ int dw_edma_probe(struct dw_edma_chip *chip)
> > goto err_irq_free;
> >
> > /* Turn debugfs on */
> > - dw_edma_v0_core_debugfs_on(dw);
> > + dw_edma_core_debugfs_on(dw);
> >
> > chip->dw = dw;
> >
> > @@ -1016,7 +981,7 @@ int dw_edma_remove(struct dw_edma_chip *chip)
> > return -ENODEV;
> >
> > /* Disable eDMA */
> > - dw_edma_v0_core_off(dw);
> > + dw_edma_core_off(dw);
> >
> > /* Free irqs */
> > for (i = (dw->nr_irqs - 1); i >= 0; i--)
> > diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
> > index 0ab2b6dba880..b0c4648cd30c 100644
> > --- a/drivers/dma/dw-edma/dw-edma-core.h
> > +++ b/drivers/dma/dw-edma/dw-edma-core.h
> > @@ -111,6 +111,19 @@ struct dw_edma {
> > raw_spinlock_t lock; /* Only for legacy */
> >
> > struct dw_edma_chip *chip;
> > +
> > + const struct dw_edma_core_ops *core;
> > +};
> > +
> > +struct dw_edma_core_ops {
> > + void (*off)(struct dw_edma *dw);
> > + u16 (*ch_count)(struct dw_edma *dw, enum dw_edma_dir dir);
> > + enum dma_status (*ch_status)(struct dw_edma_chan *chan);
> > + irqreturn_t (*handle_int)(struct dw_edma_irq *dw_irq,
> > + enum dw_edma_dir dir);
> > + void (*start)(struct dw_edma_chunk *chunk, bool first);
> > + void (*ch_config)(struct dw_edma_chan *chan);
> > + void (*debugfs_on)(struct dw_edma *dw);
> > };
> >
> > struct dw_edma_sg {
> > @@ -136,6 +149,9 @@ struct dw_edma_transfer {
> > enum dw_edma_xfer_type type;
> > };
> >
>
> > +void dw_edma_done_interrupt(struct dw_edma_chan *chan);
> > +void dw_edma_abort_interrupt(struct dw_edma_chan *chan);
>
> I'll ask one more time. So you've decided to go with the global
> dw_edma_done_interrupt()/dw_edma_abort_interrupt() methods instead of
> passing them as the function pointers to the handle_int callback.
>
> Are you sure it looks better (simpler, more readable) that way?
>
> > +
> > static inline
> > struct dw_edma_chan *vc2dw_edma_chan(struct virt_dma_chan *vc)
> > {
> > @@ -148,4 +164,52 @@ struct dw_edma_chan *dchan2dw_edma_chan(struct dma_chan *dchan)
> > return vc2dw_edma_chan(to_virt_chan(dchan));
> > }
> >
> > +static inline
> > +void dw_edma_core_off(struct dw_edma *dw)
> > +{
> > + dw->core->off(dw);
> > +}
> > +
> > +static inline
> > +u16 dw_edma_core_ch_count(struct dw_edma *dw, enum dw_edma_dir dir)
> > +{
> > + return dw->core->ch_count(dw, dir);
> > +}
> > +
> > +static inline
> > +enum dma_status dw_edma_core_ch_status(struct dw_edma_chan *chan)
> > +{
> > + struct dw_edma *dw = chan->dw;
> > +
> > + return dw->core->ch_status(chan);
> > +}
> > +
> > +static inline irqreturn_t
> > +dw_edma_core_handle_int(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir)
> > +{
> > + struct dw_edma *dw = dw_irq->dw;
> > +
> > + return dw->core->handle_int(dw_irq, dir);
> > +}
> > +
> > +static inline
> > +void dw_edma_core_start(struct dw_edma *dw, struct dw_edma_chunk *chunk, bool first)
> > +{
> > + dw->core->start(chunk, first);
> > +}
> > +
> > +static inline
> > +void dw_edma_core_ch_config(struct dw_edma_chan *chan)
> > +{
> > + struct dw_edma *dw = chan->dw;
> > +
> > + dw->core->ch_config(chan);
> > +}
> > +
> > +static inline
> > +void dw_edma_core_debugfs_on(struct dw_edma *dw)
> > +{
> > + dw->core->debugfs_on(dw);
> > +}
> > +
> > #endif /* _DW_EDMA_CORE_H */
> > diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
> > index 72e79a0c0a4e..2ebae48531f9 100644
> > --- a/drivers/dma/dw-edma/dw-edma-v0-core.c
> > +++ b/drivers/dma/dw-edma/dw-edma-v0-core.c
> > @@ -216,7 +216,7 @@ static inline u64 readq_ch(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch,
> > readq_ch(dw, dir, ch, &(__dw_ch_regs(dw, dir, ch)->name))
> >
> > /* eDMA management callbacks */
> > -void dw_edma_v0_core_off(struct dw_edma *dw)
> > +static void dw_edma_v0_core_off(struct dw_edma *dw)
> > {
> > SET_BOTH_32(dw, int_mask,
> > EDMA_V0_DONE_INT_MASK | EDMA_V0_ABORT_INT_MASK);
> > @@ -225,7 +225,7 @@ void dw_edma_v0_core_off(struct dw_edma *dw)
> > SET_BOTH_32(dw, engine_en, 0);
> > }
> >
> > -u16 dw_edma_v0_core_ch_count(struct dw_edma *dw, enum dw_edma_dir dir)
> > +static u16 dw_edma_v0_core_ch_count(struct dw_edma *dw, enum dw_edma_dir dir)
> > {
> > u32 num_ch;
> >
> > @@ -242,7 +242,7 @@ u16 dw_edma_v0_core_ch_count(struct dw_edma *dw, enum dw_edma_dir dir)
> > return (u16)num_ch;
> > }
> >
> > -enum dma_status dw_edma_v0_core_ch_status(struct dw_edma_chan *chan)
> > +static enum dma_status dw_edma_v0_core_ch_status(struct dw_edma_chan *chan)
> > {
> > struct dw_edma *dw = chan->dw;
> > u32 tmp;
> > @@ -258,7 +258,7 @@ enum dma_status dw_edma_v0_core_ch_status(struct dw_edma_chan *chan)
> > return DMA_ERROR;
> > }
> >
> > -void dw_edma_v0_core_clear_done_int(struct dw_edma_chan *chan)
> > +static void dw_edma_v0_core_clear_done_int(struct dw_edma_chan *chan)
> > {
> > struct dw_edma *dw = chan->dw;
> >
> > @@ -266,7 +266,7 @@ void dw_edma_v0_core_clear_done_int(struct dw_edma_chan *chan)
> > FIELD_PREP(EDMA_V0_DONE_INT_MASK, BIT(chan->id)));
> > }
> >
> > -void dw_edma_v0_core_clear_abort_int(struct dw_edma_chan *chan)
> > +static void dw_edma_v0_core_clear_abort_int(struct dw_edma_chan *chan)
> > {
> > struct dw_edma *dw = chan->dw;
> >
> > @@ -274,18 +274,56 @@ void dw_edma_v0_core_clear_abort_int(struct dw_edma_chan *chan)
> > FIELD_PREP(EDMA_V0_ABORT_INT_MASK, BIT(chan->id)));
> > }
> >
> > -u32 dw_edma_v0_core_status_done_int(struct dw_edma *dw, enum dw_edma_dir dir)
> > +static u32 dw_edma_v0_core_status_done_int(struct dw_edma *dw, enum dw_edma_dir dir)
> > {
> > return FIELD_GET(EDMA_V0_DONE_INT_MASK,
> > GET_RW_32(dw, dir, int_status));
> > }
> >
> > -u32 dw_edma_v0_core_status_abort_int(struct dw_edma *dw, enum dw_edma_dir dir)
> > +static u32 dw_edma_v0_core_status_abort_int(struct dw_edma *dw, enum dw_edma_dir dir)
> > {
> > return FIELD_GET(EDMA_V0_ABORT_INT_MASK,
> > GET_RW_32(dw, dir, int_status));
> > }
> >
> > +static
> > +irqreturn_t dw_edma_v0_core_handle_int(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir)
> > +{
> > + struct dw_edma *dw = dw_irq->dw;
> > + unsigned long total, pos, val;
> > + struct dw_edma_chan *chan;

> + int ret = IRQ_NONE;

I meant "irqreturn_t" type of course.

-Serge(y)

> > + unsigned long off;
> > + u32 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;
> > + }
> > +
> > + val = dw_edma_v0_core_status_done_int(dw, dir);
> > + val &= mask;
> > + for_each_set_bit(pos, &val, total) {
> > + chan = &dw->chan[pos + off];
> + newline
> > + dw_edma_v0_core_clear_done_int(chan);
> > + dw_edma_done_interrupt(chan);
> + newline
> + ret = IRQ_HANDLED;
> > + }
> > +
> > + val = dw_edma_v0_core_status_abort_int(dw, dir);
> > + val &= mask;
> > + for_each_set_bit(pos, &val, total) {
> > + chan = &dw->chan[pos + off];
> + newline
> > + dw_edma_v0_core_clear_abort_int(chan);
> > + dw_edma_abort_interrupt(chan);
> + newline
> + ret = IRQ_HANDLED;
> > + }
> > +
> > - return IRQ_HANDLED;
> + return ret;
> > +}
>
> Your version of the handler doesn't indicate whether the IRQ was
> actually handled. Instead it misleadingly returns always-handled
> status. What if no IRQ flag was actually set and no for-each
> loop was taken? It's possible for the shared IRQ lines.
>
> Besides of adding the actual IRQ-handling status return please note
> 1. newlines
> 2. include "linux/irqreturn.h" to the head of the file.
>
> -Serge(y)
>
> > +
> > static void dw_edma_v0_write_ll_data(struct dw_edma_chunk *chunk, int i,
> > u32 control, u32 size, u64 sar, u64 dar)
> > {
> > @@ -356,7 +394,7 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
> > dw_edma_v0_write_ll_link(chunk, i, control, chunk->ll_region.paddr);
> > }
> >
> > -void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
> > +static void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
> > {
> > struct dw_edma_chan *chan = chunk->chan;
> > struct dw_edma *dw = chan->dw;
> > @@ -427,7 +465,7 @@ void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
> > FIELD_PREP(EDMA_V0_DOORBELL_CH_MASK, chan->id));
> > }
> >
> > -int dw_edma_v0_core_device_config(struct dw_edma_chan *chan)
> > +static void dw_edma_v0_core_ch_config(struct dw_edma_chan *chan)
> > {
> > struct dw_edma *dw = chan->dw;
> > u32 tmp = 0;
> > @@ -494,12 +532,25 @@ int dw_edma_v0_core_device_config(struct dw_edma_chan *chan)
> > SET_RW_32(dw, chan->dir, ch67_imwr_data, tmp);
> > break;
> > }
> > -
> > - return 0;
> > }
> >
> > /* eDMA debugfs callbacks */
> > -void dw_edma_v0_core_debugfs_on(struct dw_edma *dw)
> > +static void dw_edma_v0_core_debugfs_on(struct dw_edma *dw)
> > {
> > dw_edma_v0_debugfs_on(dw);
> > }
> > +
> > +static const struct dw_edma_core_ops dw_edma_v0_core = {
> > + .off = dw_edma_v0_core_off,
> > + .ch_count = dw_edma_v0_core_ch_count,
> > + .ch_status = dw_edma_v0_core_ch_status,
> > + .handle_int = dw_edma_v0_core_handle_int,
> > + .start = dw_edma_v0_core_start,
> > + .ch_config = dw_edma_v0_core_ch_config,
> > + .debugfs_on = dw_edma_v0_core_debugfs_on,
> > +};
> > +
> > +void dw_edma_v0_core_register(struct dw_edma *dw)
> > +{
> > + dw->core = &dw_edma_v0_core;
> > +}
> > diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.h b/drivers/dma/dw-edma/dw-edma-v0-core.h
> > index ab96a1f48080..04a882222f99 100644
> > --- a/drivers/dma/dw-edma/dw-edma-v0-core.h
> > +++ b/drivers/dma/dw-edma/dw-edma-v0-core.h
> > @@ -11,17 +11,7 @@
> >
> > #include <linux/dma/edma.h>
> >
> > -/* eDMA management callbacks */
> > -void dw_edma_v0_core_off(struct dw_edma *chan);
> > -u16 dw_edma_v0_core_ch_count(struct dw_edma *chan, enum dw_edma_dir dir);
> > -enum dma_status dw_edma_v0_core_ch_status(struct dw_edma_chan *chan);
> > -void dw_edma_v0_core_clear_done_int(struct dw_edma_chan *chan);
> > -void dw_edma_v0_core_clear_abort_int(struct dw_edma_chan *chan);
> > -u32 dw_edma_v0_core_status_done_int(struct dw_edma *chan, enum dw_edma_dir dir);
> > -u32 dw_edma_v0_core_status_abort_int(struct dw_edma *chan, enum dw_edma_dir dir);
> > -void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first);
> > -int dw_edma_v0_core_device_config(struct dw_edma_chan *chan);
> > -/* eDMA debug fs callbacks */
> > -void dw_edma_v0_core_debugfs_on(struct dw_edma *dw);
> > +/* eDMA core register */
> > +void dw_edma_v0_core_register(struct dw_edma *dw);
> >
> > #endif /* _DW_EDMA_V0_CORE_H */
> > --
> > 2.34.1
> >