Re: [PATCH v4 7/8] dmaengine: dw-edma: add flags at struct dw_edma_chip

[Zhi Li <lznuaa@gmail.com>]

On Thu, Mar 10, 2022 at 11:47 AM Serge Semin <fancer.lancer@gmail.com> wrote:
>
> On Wed, Mar 09, 2022 at 03:12:03PM -0600, Frank Li wrote:
> > Allow PCI EP probe DMA locally and prevent use of remote MSI
> > to remote PCI host.
> >
> > Add option to force 32bit DBI register access even on
> > 64-bit systems. i.MX8 hardware only allowed 32bit register
> > access.
>
> Could you please split this patch up into two? These flags are
> unrelated thus adding them is two unrelated changes. That can be
> implicitly inferred from your commit log and the patch title.

I don't think it needs to be separated.  It also show why need 32bit mask to
control features and reserved futured extension capability .

The two flags were descriptions for EDMA chip features.

>
> -Sergey
>
> >
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> > Change from v3 to v4
> >  - None
> > Change from v2 to v3
> >  - rework commit message
> >  - Change to DW_EDMA_CHIP_32BIT_DBI
> >  - using DW_EDMA_CHIP_LOCAL control msi
> >  - Apply Bjorn's comments,
> >         if (!j) {
> >                control |= DW_EDMA_V0_LIE;
> >                if (!(chan->chip->flags & DW_EDMA_CHIP_LOCAL))
> >                                control |= DW_EDMA_V0_RIE;
> >         }
> >
> >         if ((chan->chip->flags & DW_EDMA_CHIP_REG32BIT) ||
> >               !IS_ENABLED(CONFIG_64BIT)) {
> >           SET_CH_32(...);
> >           SET_CH_32(...);
> >        } else {
> >           SET_CH_64(...);
> >        }
> >
> >
> > Change from v1 to v2
> > - none
> >  drivers/dma/dw-edma/dw-edma-v0-core.c | 20 ++++++++++++--------
> >  include/linux/dma/edma.h              |  9 +++++++++
> >  2 files changed, 21 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
> > index 35f2adac93e46..00a00d68d44e7 100644
> > --- a/drivers/dma/dw-edma/dw-edma-v0-core.c
> > +++ b/drivers/dma/dw-edma/dw-edma-v0-core.c
> > @@ -301,6 +301,7 @@ u32 dw_edma_v0_core_status_abort_int(struct dw_edma *dw, enum dw_edma_dir dir)
> >  static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
> >  {
> >       struct dw_edma_burst *child;
> > +     struct dw_edma_chan *chan = chunk->chan;
> >       struct dw_edma_v0_lli __iomem *lli;
> >       struct dw_edma_v0_llp __iomem *llp;
> >       u32 control = 0, i = 0;
> > @@ -314,9 +315,11 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
> >       j = chunk->bursts_alloc;
> >       list_for_each_entry(child, &chunk->burst->list, list) {
> >               j--;
> > -             if (!j)
> > -                     control |= (DW_EDMA_V0_LIE | DW_EDMA_V0_RIE);
> > -
> > +             if (!j) {
> > +                     control |= DW_EDMA_V0_LIE;
> > +                     if (!(chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL))
> > +                             control |= DW_EDMA_V0_RIE;
> > +             }
> >               /* Channel control */
> >               SET_LL_32(&lli[i].control, control);
> >               /* Transfer size */
> > @@ -414,15 +417,16 @@ void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
> >               SET_CH_32(dw, chan->dir, chan->id, ch_control1,
> >                         (DW_EDMA_V0_CCS | DW_EDMA_V0_LLE));
> >               /* Linked list */
> > -             #ifdef CONFIG_64BIT
> > -                     SET_CH_64(dw, chan->dir, chan->id, llp.reg,
> > -                               chunk->ll_region.paddr);
> > -             #else /* CONFIG_64BIT */
> > +             if ((chan->dw->chip->flags & DW_EDMA_CHIP_32BIT_DBI) ||
> > +                 !IS_ENABLED(CONFIG_64BIT)) {
> >                       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));
> > -             #endif /* CONFIG_64BIT */
> > +             } else {
> > +                     SET_CH_64(dw, chan->dir, chan->id, llp.reg,
> > +                               chunk->ll_region.paddr);
> > +             }
> >       }
> >       /* Doorbell */
> >       SET_RW_32(dw, chan->dir, doorbell,
> > diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
> > index c2039246fc08c..eea11b1d9e688 100644
> > --- a/include/linux/dma/edma.h
> > +++ b/include/linux/dma/edma.h
> > @@ -33,6 +33,12 @@ enum dw_edma_map_format {
> >       EDMA_MF_HDMA_COMPAT = 0x5
> >  };
> >
> > +/* Probe EDMA engine locally and prevent generate MSI to host side*/
> > +#define DW_EDMA_CHIP_LOCAL   BIT(0)
> > +
> > +/* Only support 32bit DBI register access */
> > +#define DW_EDMA_CHIP_32BIT_DBI       BIT(1)
> > +
> >  /**
> >   * struct dw_edma_chip - representation of DesignWare eDMA controller hardware
> >   * @dev:              struct device of the eDMA controller
> > @@ -40,6 +46,8 @@ enum dw_edma_map_format {
> >   * @nr_irqs:          total dma irq number
> >   * @ops                       DMA channel to IRQ number mapping
> >   * @reg_base          DMA register base address
> > + * @flags               - DW_EDMA_CHIP_LOCAL
> > + *                      - DW_EDMA_CHIP_32BIT_DBI
> >   * @ll_wr_cnt                 DMA write link list number
> >   * @ll_rd_cnt                 DMA read link list number
> >   * @rg_region                 DMA register region
> > @@ -53,6 +61,7 @@ struct dw_edma_chip {
> >       int                     id;
> >       int                     nr_irqs;
> >       const struct dw_edma_core_ops   *ops;
> > +     u32                     flags;
> >
> >       void __iomem            *reg_base;
> >
> > --
> > 2.24.0.rc1
> >