RE: [PATCH 3/5][v2] fsl-rio: Add two ports and rapidio messageunits support

[Liu Gang-B34182]

Hi, Alex,

Thanks for your comments, please find my replies inlines.

-----Original Message-----
From: Bounine, Alexandre [mailto:Alexandre.Bounine@xxxxxxx] 
Sent: Thursday, October 20, 2011 3:54 AM
To: Kumar Gala; linuxppc-dev@xxxxxxxxxx
Cc: Andrew Morton; Liu Gang-B34182; linux-kernel@xxxxxxxxxxxxxxx
Subject: RE: [PATCH 3/5][v2] fsl-rio: Add two ports and rapidio message units support

On Thu, Oct 13, 2011 at 10:09 AM, Kumar Gala wrote:
> 
> From: Liu Gang <Gang.Liu@xxxxxxxxxxxxx>
> 
> Usually, freescale rapidio endpoint can support one 1X or two 4X LP- 
> Serial link interfaces, and rapidio message transactions can be 
> implemented
by
> two

Is the number of 1x ports described correctly?
Can we have two 1x ports as well? 
[Liu Gang-B34182] Yes you are right. endpoint can also have two 1x ports. I'll correct it.

> message units. This patch adds the support of two rapidio ports and 
> initializes message unit 0 and message unit 1. And these ports and 
> message
... skip ...
> +
> +  /* Probe the master port phy type */
> +  ccsr = in_be32(priv->regs_win + RIO_CCSR + i*0x20);
> +  port->phy_type = (ccsr & 1) ? RIO_PHY_SERIAL :
> RIO_PHY_PARALLEL;
> +  dev_info(&dev->dev, "RapidIO PHY type: %s\n",
> +    (port->phy_type == RIO_PHY_PARALLEL) ?
> +    "parallel" :
> +    ((port->phy_type == RIO_PHY_SERIAL) ?
"serial"
> :
> +     "unknown"));
> +  /* Checking the port training status */
> +  if (in_be32((priv->regs_win + RIO_ESCSR + i*0x20)) & 1)
{
> +   dev_err(&dev->dev, "Port %d is not ready. "
> +    "Try to restart connection...\n", i);
> +   switch (port->phy_type) {
> +   case RIO_PHY_SERIAL:
> +    /* Disable ports */
> +    out_be32(priv->regs_win
> +     + RIO_CCSR + i*0x20, 0);
> +    /* Set 1x lane */
> +    setbits32(priv->regs_win
> +     + RIO_CCSR + i*0x20,
0x02000000);
> +    /* Enable ports */
> +    setbits32(priv->regs_win
> +     + RIO_CCSR + i*0x20,
0x00600000);
> +    break;
> +   case RIO_PHY_PARALLEL:
> +    /* Disable ports */
> +    out_be32(priv->regs_win
> +     + RIO_CCSR + i*0x20,
0x22000000);
> +    /* Enable ports */
> +    out_be32(priv->regs_win
> +     + RIO_CCSR + i*0x20,
0x44000000);
> +    break;
> +   }

Probably this may be a good moment to drop the support for parallel link.
Especially after you renamed controller to "srio" in the device tree.
[Liu Gang-B34182] I'm also considering if we should drop the parallel link support and doorbell outbound ATMU configuration.
I found some older powerpc chips support parallel link, like mpc8540 and so on. But DTS files of these chips do not support
Rapidio nodes. For example we can't find rapidio node in arch/powerpc/boot/dts/mpc8540ads.dts file. So can we conclude that
these chips with parallel rapidio link do not need the support for rapidio module and the code for parallel link can be removed? 

> +   msleep(100);
> +   if (in_be32((priv->regs_win
> +     + RIO_ESCSR + i*0x20)) & 1) {
> +    dev_err(&dev->dev,
> +     "Port %d restart failed.\n", i);
> +    release_resource(&port->iores);
> +    kfree(priv);
> +    kfree(port);
> +    continue;
> +   }
> +   dev_info(&dev->dev, "Port %d restart
success!\n", i);
> +  }
> +  fsl_rio_info(&dev->dev, ccsr);
> +
... skip ...
> 
>  struct rio_msg_regs {
> - u32 omr; /* 0xD_3000 - Outbound message 0 mode register
*/
> - u32 osr; /* 0xD_3004 - Outbound message 0 status register
*/
> + u32 omr;
> + u32 osr;
>   u32 pad1;
> - u32 odqdpar; /* 0xD_300C - Outbound message 0 descriptor
> queue
> -      dequeue pointer address register */
> + u32 odqdpar;
>   u32 pad2;
> - u32 osar; /* 0xD_3014 - Outbound message 0 source address
> -      register */
> - u32 odpr; /* 0xD_3018 - Outbound message 0 destination
port
> -      register */
> - u32 odatr; /* 0xD_301C - Outbound message 0 destination
> attributes
> -      Register*/
> - u32 odcr; /* 0xD_3020 - Outbound message 0 double-word
count
> -      register */
> + u32 osar;
> + u32 odpr;
> + u32 odatr;
> + u32 odcr;
>   u32 pad3;
> - u32 odqepar; /* 0xD_3028 - Outbound message 0 descriptor
> queue
> -      enqueue pointer address register */
> + u32 odqepar;
>   u32 pad4[13];
> - u32 imr; /* 0xD_3060 - Inbound message 0 mode register */
> - u32 isr; /* 0xD_3064 - Inbound message 0 status register
*/
> + u32 imr;
> + u32 isr;
>   u32 pad5;
> - u32 ifqdpar; /* 0xD_306C - Inbound message 0 frame queue
> dequeue
> -      pointer address register*/
> + u32 ifqdpar;
>   u32 pad6;
> - u32 ifqepar; /* 0xD_3074 - Inbound message 0 frame queue
> enqueue
> -      pointer address register */
> - u32 pad7[226];
> - u32 odmr; /* 0xD_3400 - Outbound doorbell mode register */
> - u32 odsr; /* 0xD_3404 - Outbound doorbell status register
*/
> + u32 ifqepar;
> + u32 pad7;

Do we need pad7 here?
[Liu Gang-B34182] Yeah, it's not required here. Forgot to remove it when re-wrote this struct.

> +};
> +
> +struct rio_dbell_regs {
> + u32 odmr;
> + u32 odsr;
>   u32 res0[4];
> - u32 oddpr; /* 0xD_3418 - Outbound doorbell destination port
> -      register */

... skip ...

> 
> @@ -340,35 +327,45 @@ fsl_rio_dbell_handler(int irq, void
> *dev_instance)
>     " sid %2.2x tid %2.2x info %4.4x\n",
>     DBELL_SID(dmsg), DBELL_TID(dmsg),
DBELL_INF(dmsg));
> 
> -  list_for_each_entry(dbell, &port->dbells, node) {
> -   if ((dbell->res->start <= DBELL_INF(dmsg)) &&
> -    (dbell->res->end >= DBELL_INF(dmsg))) {
> -    found = 1;
> -    break;
> +  for (i = 0; i < MAX_PORT_NUM; i++) {
> +   if (fsl_dbell->mport[i]) {
> +    list_for_each_entry(dbell,
> +     &fsl_dbell->mport[i]->dbells,
node) {
> +     if ((dbell->res->start
> +      <= DBELL_INF(dmsg))
> +      && (dbell->res->end
> +      >= DBELL_INF(dmsg))) {
> +      found = 1;
> +      break;
> +     }
> +    }
> +    if (found && dbell->dinb) {
> +     dbell->dinb(fsl_dbell->mport[i],
> +      dbell->dev_id,
DBELL_SID(dmsg),
> +      DBELL_TID(dmsg),
> +      DBELL_INF(dmsg));
> +     break;
> +    }
>     }
>    }

Do we need to check for matching DBELL_TID and mport destID here and scan only doorbell list attached to the right port? Otherwise this may call service routine associated with doorbell on a wrong port.
[Liu Gang-B34182] Do you mean to match DBELL_TID and mport DevID? Usually this is a reliable method, but for the rapidio module of powerpc, will encounter some problem. We set the port's DevID by
the register "Base Device ID CSR" defined in Rapidio Specification. The rapidio module of powerpc can support two ports but have only one the Base Device ID CSR. So these two ports will have the same
DevID. Although there are two registers "Alternate Device ID CSR" to separate deviceIDs for each port, they are specific registers of the freescale rapidio and can't be accessed by getting the extended feature
space block offset. For this doobell issue, in order to call a right service routine, perhaps we should ensure that different ports in different "res->start and res->end" configurations.

> -  if (found) {
> -   dbell->dinb(port, dbell->dev_id,
> -     DBELL_SID(dmsg),
> -     DBELL_TID(dmsg),
DBELL_INF(dmsg));
> -  } else {
> +
> +  if (!found) {
>     pr_debug
>      ("RIO: spurious doorbell,"
>      " sid %2.2x tid %2.2x info %4.4x\n",
>      DBELL_SID(dmsg), DBELL_TID(dmsg),
>      DBELL_INF(dmsg));
>    }
> -  setbits32(&rmu->msg_regs->dmr, DOORBELL_DMR_DI);
> -  out_be32(&rmu->msg_regs->dsr, DOORBELL_DSR_DIQI);
> +  setbits32(&fsl_dbell->dbell_regs->dmr, DOORBELL_DMR_DI);
> +  out_be32(&fsl_dbell->dbell_regs->dsr,
DOORBELL_DSR_DIQI);
>   }
> 
>  out:
>   return IRQ_HANDLED;
>  }
> 
... skip ...

> @@ -1114,50 +1104,48 @@ int fsl_rio_setup_rmu(struct rio_mport *mport, 
> struct device_node *node)  {
>   struct rio_priv *priv;
>   struct fsl_rmu *rmu;
> - struct rio_ops *ops;
> + u64 msg_start;
> + const u32 *msg_addr;
> + int mlen;
> + int aw;
> 
> - if (!mport || !mport->priv || !node)
> -  return -1;
> + if (!mport || !mport->priv)
> +  return -EFAULT;
EINVAL may be better here?
[Liu Gang-B34182] Yes EINVAL will be better and I'll correct. Thanks!

> +
> + priv = mport->priv;
> +
> + if (!node) {
> +  dev_warn(priv->dev, "Can't get %s property 'fsl,rmu'\n",
> +   priv->dev->of_node->full_name);
> +  return -EFAULT;
EINVAL as well?
[Liu Gang-B34182] Ditto.

> + }

Regards,

Alex.
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