[PATCH v5 2/7] net: macb: Add DMA 64-bit address support for macb
Ramon Fried
rfried.dev at gmail.com
Mon Dec 14 22:33:56 CET 2020
On Fri, Dec 11, 2020 at 3:27 PM Bin Meng <bmeng.cn at gmail.com> wrote:
>
> Hi Padmarao,
>
> On Fri, Dec 11, 2020 at 8:07 PM Padmarao Begari <padmarao.b at gmail.com> wrote:
> >
> > Hi Bin,
> >
> > On Fri, Dec 11, 2020 at 2:59 PM Bin Meng <bmeng.cn at gmail.com> wrote:
> >>
> >> Hi Padmarao,
> >>
> >> On Fri, Dec 11, 2020 at 4:49 PM Padmarao Begari <padmarao.b at gmail.com> wrote:
> >> >
> >> > Hi Bin,
> >> >
> >> > On Thu, Dec 10, 2020 at 4:08 PM Bin Meng <bmeng.cn at gmail.com> wrote:
> >> >>
> >> >> Hi Padmarao,
> >> >>
> >> >> On Thu, Dec 10, 2020 at 6:33 PM Bin Meng <bmeng.cn at gmail.com> wrote:
> >> >> >
> >> >> > Hi Padmarao,
> >> >> >
> >> >> > On Thu, Dec 3, 2020 at 4:44 AM Padmarao Begari
> >> >> > <padmarao.begari at microchip.com> wrote:
> >> >> > >
> >> >> > > Enable 32-bit or 64-bit DMA in the macb driver based on the macb
> >> >> > > compatible string of the device tree node.
> >> >> > >
> >> >> > > Signed-off-by: Padmarao Begari <padmarao.begari at microchip.com>
> >> >> > > Reviewed-by: Anup Patel <anup.patel at wdc.com>
> >> >> > > ---
> >> >> > > drivers/net/macb.c | 131 +++++++++++++++++++++++++++++++++++++++------
> >> >> > > drivers/net/macb.h | 6 +++
> >> >> > > 2 files changed, 120 insertions(+), 17 deletions(-)
> >> >> > >
> >> >> > > diff --git a/drivers/net/macb.c b/drivers/net/macb.c
> >> >> > > index b80a259ff7..e7c93d4747 100644
> >> >> > > --- a/drivers/net/macb.c
> >> >> > > +++ b/drivers/net/macb.c
> >> >> > > @@ -83,7 +83,16 @@ struct macb_dma_desc {
> >> >> > > u32 ctrl;
> >> >> > > };
> >> >> > >
> >> >> > > -#define DMA_DESC_BYTES(n) (n * sizeof(struct macb_dma_desc))
> >> >> > > +struct macb_dma_desc_64 {
> >> >> > > + u32 addrh;
> >> >> > > + u32 unused;
> >> >> > > +};
> >> >> > > +
> >> >> > > +#define HW_DMA_CAP_32B 0
> >> >> > > +#define HW_DMA_CAP_64B 1
> >> >> > > +
> >> >> > > +#define DMA_DESC_SIZE 16
> >> >> > > +#define DMA_DESC_BYTES(n) ((n) * DMA_DESC_SIZE)
> >> >> > > #define MACB_TX_DMA_DESC_SIZE (DMA_DESC_BYTES(MACB_TX_RING_SIZE))
> >> >> > > #define MACB_RX_DMA_DESC_SIZE (DMA_DESC_BYTES(MACB_RX_RING_SIZE))
> >> >> > > #define MACB_TX_DUMMY_DMA_DESC_SIZE (DMA_DESC_BYTES(1))
> >> >> > > @@ -133,6 +142,7 @@ struct macb_device {
> >> >> > > #endif
> >> >> > > phy_interface_t phy_interface;
> >> >> > > #endif
> >> >> > > + unsigned short hw_dma_cap;
> >> >> > > };
> >> >> > >
> >> >> > > struct macb_config {
> >> >> > > @@ -307,6 +317,24 @@ static inline void macb_invalidate_rx_buffer(struct macb_device *macb)
> >> >> > >
> >> >> > > #if defined(CONFIG_CMD_NET)
> >> >> > >
> >> >> > > +static struct macb_dma_desc_64 *macb_64b_desc(struct macb_dma_desc *desc)
> >> >> > > +{
> >> >> > > + return (struct macb_dma_desc_64 *)((void *)desc
> >> >> > > + + sizeof(struct macb_dma_desc));
> >> >> > > +}
> >> >> > > +
> >> >> > > +static void macb_set_addr(struct macb_device *macb, struct macb_dma_desc *desc,
> >> >> > > + ulong addr)
> >> >> > > +{
> >> >> > > + struct macb_dma_desc_64 *desc_64;
> >> >> > > +
> >> >> > > + if (macb->hw_dma_cap & HW_DMA_CAP_64B) {
> >> >> > > + desc_64 = macb_64b_desc(desc);
> >> >> > > + desc_64->addrh = upper_32_bits(addr);
> >> >> > > + }
> >> >> > > + desc->addr = lower_32_bits(addr);
> >> >> > > +}
> >> >> > > +
> >> >> > > static int _macb_send(struct macb_device *macb, const char *name, void *packet,
> >> >> > > int length)
> >> >> > > {
> >> >> > > @@ -325,8 +353,12 @@ static int _macb_send(struct macb_device *macb, const char *name, void *packet,
> >> >> > > macb->tx_head++;
> >> >> > > }
> >> >> > >
> >> >> > > + if (macb->hw_dma_cap & HW_DMA_CAP_64B)
> >> >> > > + tx_head = tx_head * 2;
> >> >> > > +
> >> >> > > macb->tx_ring[tx_head].ctrl = ctrl;
> >> >> > > - macb->tx_ring[tx_head].addr = paddr;
> >> >> > > + macb_set_addr(macb, &macb->tx_ring[tx_head], paddr);
> >> >> > > +
> >> >> > > barrier();
> >> >> > > macb_flush_ring_desc(macb, TX);
> >> >> > > macb_writel(macb, NCR, MACB_BIT(TE) | MACB_BIT(RE) | MACB_BIT(TSTART));
> >> >> > > @@ -363,19 +395,28 @@ static void reclaim_rx_buffers(struct macb_device *macb,
> >> >> > > unsigned int new_tail)
> >> >> > > {
> >> >> > > unsigned int i;
> >> >> > > + unsigned int count;
> >> >> > >
> >> >> > > i = macb->rx_tail;
> >> >> > >
> >> >> > > macb_invalidate_ring_desc(macb, RX);
> >> >> > > while (i > new_tail) {
> >> >> > > - macb->rx_ring[i].addr &= ~MACB_BIT(RX_USED);
> >> >> > > + if (macb->hw_dma_cap & HW_DMA_CAP_64B)
> >> >> > > + count = i * 2;
> >> >> > > + else
> >> >> > > + count = i;
> >> >> > > + macb->rx_ring[count].addr &= ~MACB_BIT(RX_USED);
> >> >> > > i++;
> >> >> > > if (i > MACB_RX_RING_SIZE)
> >> >> > > i = 0;
> >> >> > > }
> >> >> > >
> >> >> > > while (i < new_tail) {
> >> >> > > - macb->rx_ring[i].addr &= ~MACB_BIT(RX_USED);
> >> >> > > + if (macb->hw_dma_cap & HW_DMA_CAP_64B)
> >> >> > > + count = i * 2;
> >> >> > > + else
> >> >> > > + count = i;
> >> >> > > + macb->rx_ring[count].addr &= ~MACB_BIT(RX_USED);
> >> >> > > i++;
> >> >> > > }
> >> >> > >
> >> >> > > @@ -390,16 +431,25 @@ static int _macb_recv(struct macb_device *macb, uchar **packetp)
> >> >> > > void *buffer;
> >> >> > > int length;
> >> >> > > u32 status;
> >> >> > > + u8 flag = false;
> >> >> > >
> >> >> > > macb->wrapped = false;
> >> >> > > for (;;) {
> >> >> > > macb_invalidate_ring_desc(macb, RX);
> >> >> > >
> >> >> > > + if (macb->hw_dma_cap & HW_DMA_CAP_64B)
> >> >> > > + next_rx_tail = next_rx_tail * 2;
> >> >> > > +
> >> >> > > if (!(macb->rx_ring[next_rx_tail].addr & MACB_BIT(RX_USED)))
> >> >> > > return -EAGAIN;
> >> >> > >
> >> >> > > status = macb->rx_ring[next_rx_tail].ctrl;
> >> >> > > if (status & MACB_BIT(RX_SOF)) {
> >> >> > > + if (macb->hw_dma_cap & HW_DMA_CAP_64B) {
> >> >> > > + next_rx_tail = next_rx_tail / 2;
> >> >> > > + flag = true;
> >> >> > > + }
> >> >> > > +
> >> >> > > if (next_rx_tail != macb->rx_tail)
> >> >> > > reclaim_rx_buffers(macb, next_rx_tail);
> >> >> > > macb->wrapped = false;
> >> >> > > @@ -426,11 +476,22 @@ static int _macb_recv(struct macb_device *macb, uchar **packetp)
> >> >> > > *packetp = buffer;
> >> >> > > }
> >> >> > >
> >> >> > > + if (macb->hw_dma_cap & HW_DMA_CAP_64B) {
> >> >> > > + if (!flag)
> >> >> > > + next_rx_tail = next_rx_tail / 2;
> >> >> > > + }
> >> >> > > +
> >> >> > > if (++next_rx_tail >= MACB_RX_RING_SIZE)
> >> >> > > next_rx_tail = 0;
> >> >> > > macb->next_rx_tail = next_rx_tail;
> >> >> > > return length;
> >> >> > > } else {
> >> >> > > + if (macb->hw_dma_cap & HW_DMA_CAP_64B) {
> >> >> > > + if (!flag)
> >> >> > > + next_rx_tail = next_rx_tail / 2;
> >> >> > > + flag = false;
> >> >> > > + }
> >> >> > > +
> >> >> > > if (++next_rx_tail >= MACB_RX_RING_SIZE) {
> >> >> > > macb->wrapped = true;
> >> >> > > next_rx_tail = 0;
> >> >> > > @@ -718,6 +779,7 @@ static int gmac_init_multi_queues(struct macb_device *macb)
> >> >> > > {
> >> >> > > int i, num_queues = 1;
> >> >> > > u32 queue_mask;
> >> >> > > + unsigned long paddr;
> >> >> > >
> >> >> > > /* bit 0 is never set but queue 0 always exists */
> >> >> > > queue_mask = gem_readl(macb, DCFG6) & 0xff;
> >> >> > > @@ -731,10 +793,18 @@ static int gmac_init_multi_queues(struct macb_device *macb)
> >> >> > > macb->dummy_desc->addr = 0;
> >> >> > > 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);
> >> >> > > -
> >> >> > > + paddr = macb->dummy_desc_dma;
> >> >> > > +
> >> >> > > + for (i = 1; i < num_queues; i++) {
> >> >> > > + gem_writel_queue_TBQP(macb, lower_32_bits(paddr), i - 1);
> >> >> > > + gem_writel_queue_RBQP(macb, lower_32_bits(paddr), i - 1);
> >> >> > > + if (macb->hw_dma_cap & HW_DMA_CAP_64B) {
> >> >> > > + gem_writel_queue_TBQPH(macb, upper_32_bits(paddr),
> >> >> > > + i - 1);
> >> >> > > + gem_writel_queue_RBQPH(macb, upper_32_bits(paddr),
> >> >> > > + i - 1);
> >> >> > > + }
> >> >> > > + }
> >> >> > > return 0;
> >> >> > > }
> >> >> > >
> >> >> > > @@ -760,6 +830,9 @@ static void gmac_configure_dma(struct macb_device *macb)
> >> >> > > dmacfg &= ~GEM_BIT(ENDIA_DESC);
> >> >> > >
> >> >> > > dmacfg &= ~GEM_BIT(ADDR64);
> >> >> > > + if (macb->hw_dma_cap & HW_DMA_CAP_64B)
> >> >> > > + dmacfg |= GEM_BIT(ADDR64);
> >> >>
> >> >> Does GEM on PolarFire not support 32-bit DMA address? I believe in
> >> >> U-Boot we can only get 32-bit address.
> >> >>
> >> >
> >> > Yes, it's not work when I tested with 32-bit DMA.
> >>
> >> Okay, then this explains why 64-bit DMA patch is needed. Is this a bug
> >> of the GEM IP integrated in the PolarFire?
> >> Could you please write something in the commit message to clarify?
> >> That would be helpful. Thanks!
> >
> >
> > No, it's not a bug, The PolarFire SoC Memory Protection Unit(MPU) gives the 64-bit DMA access with GEM, the MPU transactions on the AXI bus is 64-bit not 32-bit.
>
> This sounds like a GEM IP integration configuration issue on PolarFire.
Actually, I also stumbled upon a situation where I needed to use 64bit
addressing on MACB because IOMMU bits I had to add to the address.
It didn't end up as a patch, but it make sense to support it although
U-boot wil provide lower addresses.
>
> Regards,
> Bin
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