Messages in this thread | | | Date | Fri, 26 Apr 2019 11:40:13 -0700 | From | Jakub Kicinski <> | Subject | Re: [PATCH 03/12] net: ll_temac: Fix support for 64-bit platforms |
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On Fri, 26 Apr 2019 09:32:22 +0200, Esben Haabendal wrote: > The use of buffer descriptor APP4 field (32-bit) for storing skb pointer > obviously does not work on 64-bit platforms. > As APP3 is also unused, we can use that to store the other half of 64-bit > pointer values. > > Contrary to what is hinted at in commit message of commit 15bfe05c8d63 > ("net: ethernet: xilinx: Mark XILINX_LL_TEMAC broken on 64-bit") > there are no other pointers stored in cdmac_bd. > > Signed-off-by: Esben Haabendal <esben@geanix.com>
This is a bit strange, the driver stores the host's virtual address into the HW descriptor?
> diff --git a/drivers/net/ethernet/xilinx/Kconfig b/drivers/net/ethernet/xilinx/Kconfig > index da4ec57..6d68c8a 100644 > --- a/drivers/net/ethernet/xilinx/Kconfig > +++ b/drivers/net/ethernet/xilinx/Kconfig > @@ -34,7 +34,6 @@ config XILINX_AXI_EMAC > config XILINX_LL_TEMAC > tristate "Xilinx LL TEMAC (LocalLink Tri-mode Ethernet MAC) driver" > depends on (PPC || MICROBLAZE) > - depends on !64BIT || BROKEN > select PHYLIB > ---help--- > This driver supports the Xilinx 10/100/1000 LocalLink TEMAC > diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c > index 4594fe3..a365bfd 100644 > --- a/drivers/net/ethernet/xilinx/ll_temac_main.c > +++ b/drivers/net/ethernet/xilinx/ll_temac_main.c > @@ -619,11 +619,39 @@ static void temac_adjust_link(struct net_device *ndev) > mutex_unlock(&lp->indirect_mutex); > } > > +#ifdef CONFIG_64BIT > + > +void ptr_to_txbd(void *p, struct cdmac_bd *bd) > +{ > + bd->app3 = (u32)(((u64)p) >> 32); > + bd->app4 = (u32)((u64)p & 0xFFFFFFFF); > +} > + > +void *ptr_from_txbd(struct cdmac_bd *bd) > +{ > + return (void *)(((u64)(bd->app3) << 32) | bd->app4); > +} > + > +#else > + > +void ptr_to_txbd(void *p, struct cmdac_bd *bd) > +{ > + bd->app4 = (u32)p; > +} > + > +void *ptr_from_txbd(struct cdmac_bd *bd) > +{ > + return (void *)(bd->app4); > +} > + > +#endif > + > static void temac_start_xmit_done(struct net_device *ndev) > { > struct temac_local *lp = netdev_priv(ndev); > struct cdmac_bd *cur_p; > unsigned int stat = 0; > + struct sk_buff *skb; > > cur_p = &lp->tx_bd_v[lp->tx_bd_ci]; > stat = cur_p->app0; > @@ -631,8 +659,9 @@ static void temac_start_xmit_done(struct net_device *ndev) > while (stat & STS_CTRL_APP0_CMPLT) { > dma_unmap_single(ndev->dev.parent, cur_p->phys, cur_p->len, > DMA_TO_DEVICE); > - if (cur_p->app4) > - dev_consume_skb_irq((struct sk_buff *)cur_p->app4); > + skb = (struct sk_buff *)ptr_from_txbd(cur_p); > + if (skb) > + dev_consume_skb_irq(skb); > cur_p->app0 = 0; > cur_p->app1 = 0; > cur_p->app2 = 0; > @@ -711,7 +740,7 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev) > cur_p->len = skb_headlen(skb); > cur_p->phys = dma_map_single(ndev->dev.parent, skb->data, > skb_headlen(skb), DMA_TO_DEVICE); > - cur_p->app4 = (unsigned long)skb; > + ptr_to_txbd((void *)skb, cur_p); > > for (ii = 0; ii < num_frag; ii++) { > lp->tx_bd_tail++;
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