[PATCH v2 2/7] net: macb: Add DMA 64-bit address support for macb

[Padmarao Begari]

Hi Anup,

On Sun, Oct 25, 2020 at 11:37 AM Anup Patel <anup at brainfault.org> wrote:

> On Thu, Oct 22, 2020 at 12:52 PM Padmarao Begari
> <padmarao.begari at microchip.com> wrote:
> >
> > Enable 64-bit DMA support in the macb driver when CONFIG_DMA_ADDR_T_64BIT
> > is enabled. 32-bit DMA is enabled by default.
> >
> > Signed-off-by: Padmarao Begari <padmarao.begari at microchip.com>
> > ---
> >  drivers/net/macb.c | 46 ++++++++++++++++++++++++++++++++++++++--------
> >  drivers/net/macb.h |  6 ++++++
> >  2 files changed, 44 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/net/macb.c b/drivers/net/macb.c
> > index b80a259ff7..e0e86a274e 100644
> > --- a/drivers/net/macb.c
> > +++ b/drivers/net/macb.c
> > @@ -81,6 +81,10 @@ DECLARE_GLOBAL_DATA_PTR;
> >  struct macb_dma_desc {
> >         u32     addr;
> >         u32     ctrl;
> > +#ifdef CONFIG_DMA_ADDR_T_64BIT
> > +       u32 addrh;
> > +       u32 unused;
> > +#endif
> >  };
> >
> >  #define DMA_DESC_BYTES(n)      (n * sizeof(struct macb_dma_desc))
> > @@ -326,7 +330,10 @@ static int _macb_send(struct macb_device *macb,
> const char *name, void *packet,
> >         }
> >
> >         macb->tx_ring[tx_head].ctrl = ctrl;
> > -       macb->tx_ring[tx_head].addr = paddr;
> > +       macb->tx_ring[tx_head].addr = lower_32_bits(paddr);
> > +#ifdef CONFIG_DMA_ADDR_T_64BIT
> > +       macb->tx_ring[tx_head].addrh = upper_32_bits(paddr);
> > +#endif
> >         barrier();
> >         macb_flush_ring_desc(macb, TX);
> >         macb_writel(macb, NCR, MACB_BIT(TE) | MACB_BIT(RE) |
> MACB_BIT(TSTART));
> > @@ -732,9 +739,20 @@ static int gmac_init_multi_queues(struct
> macb_device *macb)
> >         flush_dcache_range(macb->dummy_desc_dma, macb->dummy_desc_dma +
> >                         ALIGN(MACB_TX_DUMMY_DMA_DESC_SIZE, PKTALIGN));
> >
> > -       for (i = 1; i < num_queues; i++)
> > -               gem_writel_queue_TBQP(macb, macb->dummy_desc_dma, i - 1);
> > -
> > +       for (i = 1; i < num_queues; i++) {
> > +               gem_writel_queue_TBQP(macb,
> > +                       lower_32_bits(macb->dummy_desc_dma), i - 1);
> > +#ifdef CONFIG_DMA_ADDR_T_64BIT
> > +               gem_writel_queue_TBQPH(macb,
> > +                       upper_32_bits(macb->dummy_desc_dma), i - 1);
> > +#endif
> > +               gem_writel_queue_RBQP(macb,
> > +                       lower_32_bits(macb->dummy_desc_dma), i - 1);
> > +#ifdef CONFIG_DMA_ADDR_T_64BIT
> > +               gem_writel_queue_RBQPH(macb,
> > +                       upper_32_bits(macb->dummy_desc_dma), i - 1);
> > +#endif
> > +       }
> >         return 0;
> >  }
> >
> > @@ -760,6 +778,9 @@ static void gmac_configure_dma(struct macb_device
> *macb)
> >                 dmacfg &= ~GEM_BIT(ENDIA_DESC);
> >
> >         dmacfg &= ~GEM_BIT(ADDR64);
> > +#ifdef CONFIG_DMA_ADDR_T_64BIT
> > +       dmacfg |= GEM_BIT(ADDR64);
> > +#endif
> >         gem_writel(macb, DMACFG, dmacfg);
> >  }
> >
> > @@ -786,8 +807,11 @@ static int _macb_init(struct macb_device *macb,
> const char *name)
> >         for (i = 0; i < MACB_RX_RING_SIZE; i++) {
> >                 if (i == (MACB_RX_RING_SIZE - 1))
> >                         paddr |= MACB_BIT(RX_WRAP);
> > -               macb->rx_ring[i].addr = paddr;
> > +               macb->rx_ring[i].addr = lower_32_bits(paddr);
> >                 macb->rx_ring[i].ctrl = 0;
> > +#ifdef CONFIG_DMA_ADDR_T_64BIT
> > +               macb->rx_ring[i].addrh = upper_32_bits(paddr);
> > +#endif
> >                 paddr += macb->rx_buffer_size;
> >         }
> >         macb_flush_ring_desc(macb, RX);
> > @@ -800,6 +824,9 @@ static int _macb_init(struct macb_device *macb,
> const char *name)
> >                                 MACB_BIT(TX_WRAP);
> >                 else
> >                         macb->tx_ring[i].ctrl = MACB_BIT(TX_USED);
> > +#ifdef CONFIG_DMA_ADDR_T_64BIT
> > +               macb->tx_ring[i].addrh = 0x0;
> > +#endif
> >         }
> >         macb_flush_ring_desc(macb, TX);
> >
> > @@ -812,9 +839,12 @@ static int _macb_init(struct macb_device *macb,
> const char *name)
> >         gem_writel(macb, DMACFG, MACB_ZYNQ_GEM_DMACR_INIT);
> >  #endif
> >
> > -       macb_writel(macb, RBQP, macb->rx_ring_dma);
> > -       macb_writel(macb, TBQP, macb->tx_ring_dma);
> > -
> > +       macb_writel(macb, RBQP, lower_32_bits(macb->rx_ring_dma));
> > +       macb_writel(macb, TBQP, lower_32_bits(macb->tx_ring_dma));
> > +#ifdef CONFIG_DMA_ADDR_T_64BIT
> > +       macb_writel(macb, RBQPH, upper_32_bits(macb->rx_ring_dma));
> > +       macb_writel(macb, TBQPH, upper_32_bits(macb->tx_ring_dma));
> > +#endif
> >         if (macb_is_gem(macb)) {
> >                 /* Initialize DMA properties */
> >                 gmac_configure_dma(macb);
> > diff --git a/drivers/net/macb.h b/drivers/net/macb.h
> > index 9b16383eba..72b84ae96e 100644
> > --- a/drivers/net/macb.h
> > +++ b/drivers/net/macb.h
> > @@ -768,5 +768,11 @@
> >  #define GEM_RX_CSUM_CHECKED_MASK               2
> >  #define gem_writel_queue_TBQP(port, value, queue_num)  \
> >         writel((value), (port)->regs + GEM_TBQP(queue_num))
> > +#define gem_writel_queue_TBQPH(port, value, queue_num) \
> > +       writel((value), (port)->regs + GEM_TBQPH(queue_num))
> > +#define gem_writel_queue_RBQP(port, value, queue_num)  \
> > +       writel((value), (port)->regs + GEM_RBQP(queue_num))
> > +#define gem_writel_queue_RBQPH(port, value, queue_num) \
> > +       writel((value), (port)->regs + GEM_RBQPH(queue_num))
> >
> >  #endif /* __DRIVERS_MACB_H__ */
> > --
> > 2.17.1
> >
>
> Is there a way to know whether MACB hardware support 64bit
> DMA address using some MACB version/capability register ?
> If yes then please use runtime check instead of "#ifdef"
>
> Yes, design config debug6 register available.

Regards
Padmarao

> Regards,
> Anup
>