[PATCH v5 2/7] net: macb: Add DMA 64-bit address support for macb
Bin Meng
bmeng.cn at gmail.com
Fri Dec 11 14:26:44 CET 2020
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.
Regards,
Bin
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