Re: [dpdk-dev] [EXT] Re: [PATCH v6 2/5] net/enetfec: add UIO support

[Apeksha Gupta <apeksha.gupta@nxp.com>]

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Wednesday, October 27, 2021 7:52 PM
> To: Apeksha Gupta <apeksha.gupta@nxp.com>;
> david.marchand@redhat.com; andrew.rybchenko@oktetlabs.ru;
> ferruh.yigit@intel.com
> Cc: dev@dpdk.org; Sachin Saxena <sachin.saxena@nxp.com>; Hemant
> Agrawal <hemant.agrawal@nxp.com>
> Subject: [EXT] Re: [dpdk-dev] [PATCH v6 2/5] net/enetfec: add UIO support
> 
> Caution: EXT Email
> 
> On 10/21/2021 5:46 AM, Apeksha Gupta wrote:
> > Implemented the fec-uio driver in kernel. enetfec PMD uses
> > UIO interface to interact with "fec-uio" driver implemented in
> > kernel for PHY initialisation and for mapping the allocated memory
> > of register & BD from kernel to DPDK which gives access to
> > non-cacheable memory for BD.
> >
> > Signed-off-by: Sachin Saxena <sachin.saxena@nxp.com>
> > Signed-off-by: Apeksha Gupta <apeksha.gupta@nxp.com>
> 
> <...>
> 
> > +
> > +#define NUM_OF_QUEUES                        6
> 
> I guess this is number of BD queues, may be good to have it in macro name.
[Apeksha] okay, updated in v7 patch series.

> 
> > +
> > +uint32_t e_cntl;
> > +
> 
> Is this global variable really needed, most of the times what you need is
> per port varible.
> For example I can see this variable is updated based on port start/stop,
> what if you have multiple ports and they are different start/stop state,
> will the value of variable still be correct?
> 
> And if it will be global, can you please make it 'static' and prefix driver
> namespace to it?
[Apeksha] Sure, we will update.

> 
> > +/*
> > + * This function is called to start or restart the ENETFEC during a link
> > + * change, transmit timeout, or to reconfigure the ENETFEC. The network
> > + * packet processing for this device must be stopped before this call.
> > + */
> > +static void
> > +enetfec_restart(struct rte_eth_dev *dev)
> > +{
> > +     struct enetfec_private *fep = dev->data->dev_private;
> > +     uint32_t temp_mac[2];
> > +     uint32_t rcntl = OPT_FRAME_SIZE | 0x04;
> > +     uint32_t ecntl = ENETFEC_ETHEREN;
> > +
> > +     /* default mac address */
> > +     struct rte_ether_addr addr = {
> > +             .addr_bytes = {0x1, 0x2, 0x3, 0x4, 0x5, 0x6} };
> > +     uint32_t val;
> > +
> > +     /*
> > +      * enet-mac reset will reset mac address registers too,
> > +      * so need to reconfigure it.
> > +      */
> > +     memcpy(&temp_mac, addr.addr_bytes, ETH_ALEN);
> > +     rte_write32(rte_cpu_to_be_32(temp_mac[0]),
> > +             (uint8_t *)fep->hw_baseaddr_v + ENETFEC_PALR);
> > +     rte_write32(rte_cpu_to_be_32(temp_mac[1]),
> > +             (uint8_t *)fep->hw_baseaddr_v + ENETFEC_PAUR);
> > +
> 
> Is same MAC address used for all ports?
> 
> Also probe sets a different MAC address, which one is valid?
[Apeksha] we will remove MAC address from here in next version. Also mac address feature is yet to be implemented. At present sets the fixed mac address from probe.

> <...>
> 
> > +
> > +static int
> > +enetfec_eth_start(struct rte_eth_dev *dev)
> > +{
> > +     enetfec_restart(dev);
> > +
> > +     return 0;
> > +}
> 
> Empty line is missing between two functions.
[Apeksha] okay.

> 
> > +/* ENETFEC enable function.
> > + * @param[in] base      ENETFEC base address
> > + */
> > +void
> > +enetfec_enable(void *base)
> > +{
> > +     rte_write32(rte_read32((uint8_t *)base + ENETFEC_ECR) | e_cntl,
> > +                                     (uint8_t *)base + ENETFEC_ECR);
> > +}
> > +
> > +/* ENETFEC disable function.
> > + * @param[in] base      ENETFEC base address
> > + */
> > +void
> > +enetfec_disable(void *base)
> > +{
> > +     rte_write32(rte_read32((uint8_t *)base + ENETFEC_ECR) & ~e_cntl,
> > +                                     (uint8_t *)base + ENETFEC_ECR);
> > +}
> > +
> 
> Are these 'enetfec_enable()'/'enetfec_disable()' functions used out of this
> file,
> if not why not make them static, and remove definition in header file?
[Apeksha] I do agree as these functions not used out of the file. Updated in v7 patch series.

> 
> > +static int
> > +enetfec_eth_stop(__rte_unused struct rte_eth_dev *dev)
> 
> 'dev' is used, so can drop '__rte_unused'.
[Apeksha] okay.

> 
> > +{
> > +     struct enetfec_private *fep = dev->data->dev_private;
> > +
> > +     dev->data->dev_started = 0;
> > +     enetfec_disable(fep->hw_baseaddr_v);
> > +
> > +     return 0;
> > +}
> 
> <...>