[PATCH] [V2] Add non-Virtex5 support for LL TEMAC driver

Michal Simek michal.simek at petalogix.com
Tue Mar 16 01:57:57 EST 2010


John Linn wrote:
>> -----Original Message-----
>> From: Michal Simek [mailto:michal.simek at petalogix.com]
>> Sent: Monday, March 15, 2010 8:40 AM
>> To: John Linn
>> Cc: netdev at vger.kernel.org; linuxppc-dev at ozlabs.org;
> grant.likely at secretlab.ca;
>> jwboyer at linux.vnet.ibm.com; john.williams at petalogix.com; John Tyner
>> Subject: Re: [PATCH] [V2] Add non-Virtex5 support for LL TEMAC driver
>>
>> John Linn wrote:
>>>> -----Original Message-----
>>>> From: Michal Simek [mailto:michal.simek at petalogix.com]
>>>> Sent: Monday, March 15, 2010 2:40 AM
>>>> To: John Linn
>>>> Cc: netdev at vger.kernel.org; linuxppc-dev at ozlabs.org;
>>> grant.likely at secretlab.ca;
>>>> jwboyer at linux.vnet.ibm.com; john.williams at petalogix.com; John Tyner
>>>> Subject: Re: [PATCH] [V2] Add non-Virtex5 support for LL TEMAC
> driver
>>>> John Linn wrote:
>>>>> This patch adds support for using the LL TEMAC Ethernet driver on
>>>>> non-Virtex 5 platforms by adding support for accessing the Soft
> DMA
>>>>> registers as if they were memory mapped instead of solely through
>>> the
>>>>> DCR's (available on the Virtex 5).
>>>>>
>>>>> The patch also updates the driver so that it runs on the
> MicroBlaze.
>>>>> The changes were tested on the PowerPC 440, PowerPC 405, and the
>>>>> MicroBlaze platforms.
>>>> Which git-tree have you tested on? (Of course microblaze)
>>> It was tested on the Xilinx tree for MicroBlaze which is based on
> the
>>> mainline and the Petalogix tree as DMA was needed. I tried to build
>>> against the mainline head but got errors with the DMA routines. I
> guess
>>> it's possible that it was a configuration issue there as I didn't
> dig
>>> real deep.
>> New dma api is in for-linus branch.
>> I tested it on that version and I am seeing some weird things. :-(
>> Access to bad area. I will try your tree.
>>
>> The second thing which I see is in ll_temac_recv function.
>> On the following line is read a packet length which could be 0-16k.
>> 		length = cur_p->app4 & 0x3FFF;
>>
>> But allocated skb has max size XTE_MAX_JUMBO_FRAME_SIZE + XTE_ALIGN.
>>
>> What happen if driver get packet greater than 9kB?
>> I got it (I don't know how) but skb_put has one checking mechanism
> which
>> will cal skb_over_panic which caused panic.
> 
> That's the whole reason for that panic to me and when I got it in the
> past and looked it up it made sense to me.  I personally don't see a
> good reason to check for it in the driver since the kernel catches it,
> but maybe others do.

yes, kernel is checking it but caused panic which ends in fault in 
kernel and caused kernel crash. :-( This could be a good reason to check 
it in driver. I don't want to reset the board when ll_temac gets longer 
packet, do you?

I have seen the second type of fault which caused kernel access to bad 
area (+ kernel panic). Have you done any iperf tests or flood ping?

Thanks,
Michal

> 
> Thanks,
> John
> 
>> That's why I think that will be good always to check that length is
> less
>> than XTE_MAX_JUMBO_FRAME_SIZE + XTE_ALIGN.
>>
>> What do you think?
>>
>> Thanks,
>> Michal
>>
>>> I tested the PowerPC against the head of mainline.
>>>
>>> Thanks,
>>> John
>>>
>>>> Michal
>>>>
>>>>> Signed-off-by: John Tyner <jtyner at cs.ucr.edu>
>>>>> Signed-off-by: John Linn <john.linn at xilinx.com>
>>>>> ---
>>>>>
>>>>> V2 - Incorporated comments from Grant and added more logic to
> allow
>>> the driver
>>>>> to work on MicroBlaze.
>>>>>
>>>>>  drivers/net/Kconfig         |    1 -
>>>>>  drivers/net/ll_temac.h      |   17 +++++-
>>>>>  drivers/net/ll_temac_main.c |  124
>>> ++++++++++++++++++++++++++++++++++---------
>>>>>  3 files changed, 113 insertions(+), 29 deletions(-)
>>>>>
>>>>> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
>>>>> index 9b6efe1..5402105 100644
>>>>> --- a/drivers/net/Kconfig
>>>>> +++ b/drivers/net/Kconfig
>>>>> @@ -2443,7 +2443,6 @@ config MV643XX_ETH
>>>>>  config XILINX_LL_TEMAC
>>>>>  	tristate "Xilinx LL TEMAC (LocalLink Tri-mode Ethernet MAC)
>>> driver"
>>>>>  	select PHYLIB
>>>>> -	depends on PPC_DCR_NATIVE
>>>>>  	help
>>>>>  	  This driver supports the Xilinx 10/100/1000 LocalLink TEMAC
>>>>>  	  core used in Xilinx Spartan and Virtex FPGAs
>>>>> diff --git a/drivers/net/ll_temac.h b/drivers/net/ll_temac.h
>>>>> index 1af66a1..915aa34 100644
>>>>> --- a/drivers/net/ll_temac.h
>>>>> +++ b/drivers/net/ll_temac.h
>>>>> @@ -5,8 +5,11 @@
>>>>>  #include <linux/netdevice.h>
>>>>>  #include <linux/of.h>
>>>>>  #include <linux/spinlock.h>
>>>>> +
>>>>> +#ifdef CONFIG_PPC_DCR
>>>>>  #include <asm/dcr.h>
>>>>>  #include <asm/dcr-regs.h>
>>>>> +#endif
>>>>>
>>>>>  /* packet size info */
>>>>>  #define XTE_HDR_SIZE			14      /* size of
>>> Ethernet header */
>>>>> @@ -290,8 +293,12 @@ This option defaults to enabled (set) */
>>>>>
>>>>>  #define TX_CONTROL_CALC_CSUM_MASK   1
>>>>>
>>>>> +/* Align the IP data in the packet on word boundaries as
> MicroBlaze
>>>>> + * needs it.
>>>>> + */
>>>>> +
>>>>>  #define XTE_ALIGN       32
>>>>> -#define BUFFER_ALIGN(adr) ((XTE_ALIGN - ((u32) adr)) % XTE_ALIGN)
>>>>> +#define BUFFER_ALIGN(adr) ((34 - ((u32) adr)) % XTE_ALIGN)
>>>>>
>>>>>  #define MULTICAST_CAM_TABLE_NUM 4
>>>>>
>>>>> @@ -335,9 +342,15 @@ struct temac_local {
>>>>>  	struct mii_bus *mii_bus;	/* MII bus reference */
>>>>>  	int mdio_irqs[PHY_MAX_ADDR];	/* IRQs table for MDIO bus */
>>>>>
>>>>> -	/* IO registers and IRQs */
>>>>> +	/* IO registers, dma functions and IRQs */
>>>>>  	void __iomem *regs;
>>>>> +	void __iomem *sdma_regs;
>>>>> +#ifdef CONFIG_PPC_DCR
>>>>>  	dcr_host_t sdma_dcrs;
>>>>> +#endif
>>>>> +	u32 (*dma_in)(struct temac_local *, int);
>>>>> +	void (*dma_out)(struct temac_local *, int, u32);
>>>>> +
>>>>>  	int tx_irq;
>>>>>  	int rx_irq;
>>>>>  	int emac_num;
>>>>> diff --git a/drivers/net/ll_temac_main.c
>>> b/drivers/net/ll_temac_main.c
>>>>> index a18e348..9aedf9b 100644
>>>>> --- a/drivers/net/ll_temac_main.c
>>>>> +++ b/drivers/net/ll_temac_main.c
>>>>> @@ -20,9 +20,6 @@
>>>>>   *   or rx, so this should be okay.
>>>>>   *
>>>>>   * TODO:
>>>>> - * - Fix driver to work on more than just Virtex5.  Right now the
>>> driver
>>>>> - *   assumes that the locallink DMA registers are accessed via
> DCR
>>>>> - *   instructions.
>>>>>   * - Factor out locallink DMA code into separate driver
>>>>>   * - Fix multicast assignment.
>>>>>   * - Fix support for hardware checksumming.
>>>>> @@ -115,17 +112,86 @@ void temac_indirect_out32(struct temac_local
>>> *lp, int reg, u32 value)
>>>>>  	temac_iow(lp, XTE_CTL0_OFFSET, CNTLREG_WRITE_ENABLE_MASK | reg);
>>>>>  }
>>>>>
>>>>> +/**
>>>>> + * temac_dma_in32 - Memory mapped DMA read, this function expects
> a
>>>>> + * register input that is based on DCR word addresses which
>>>>> + * are then converted to memory mapped byte addresses
>>>>> + */
>>>>>  static u32 temac_dma_in32(struct temac_local *lp, int reg)
>>>>>  {
>>>>> -	return dcr_read(lp->sdma_dcrs, reg);
>>>>> +	return in_be32((u32 *)(lp->sdma_regs + (reg << 2)));
>>>>>  }
>>>>>
>>>>> +/**
>>>>> + * temac_dma_out32 - Memory mapped DMA read, this function
> expects
>>> a
>>>>> + * register input that is based on DCR word addresses which
>>>>> + * are then converted to memory mapped byte addresses
>>>>> + */
>>>>>  static void temac_dma_out32(struct temac_local *lp, int reg, u32
>>> value)
>>>>>  {
>>>>> +	out_be32((u32 *)(lp->sdma_regs + (reg << 2)), value);
>>>>> +}
>>>>> +
>>>>> +/* DMA register access functions can be DCR based or memory
> mapped.
>>>>> + * The PowerPC 440 is DCR based, the PowerPC 405 and MicroBlaze
> are
>>> both
>>>>> + * memory mapped.
>>>>> + */
>>>>> +#ifdef CONFIG_PPC_DCR
>>>>> +
>>>>> +/**
>>>>> + * temac_dma_dcr_in32 - DCR based DMA read
>>>>> + */
>>>>> +static u32 temac_dma_dcr_in(struct temac_local *lp, int reg)
>>>>> +{
>>>>> +	return dcr_read(lp->sdma_dcrs, reg);
>>>>> +}
>>>>> +
>>>>> +/**
>>>>> + * temac_dma_dcr_out32 - DCR based DMA write
>>>>> + */
>>>>> +static void temac_dma_dcr_out(struct temac_local *lp, int reg,
> u32
>>> value)
>>>>> +{
>>>>>  	dcr_write(lp->sdma_dcrs, reg, value);
>>>>>  }
>>>>>
>>>>>  /**
>>>>> + * temac_dcr_setup - If the DMA is DCR based, then setup the
>>> address and
>>>>> + * I/O  functions
>>>>> + */
>>>>> +static int temac_dcr_setup(struct temac_local *lp, struct
> of_device
>>> *op,
>>>>> +				struct device_node *np)
>>>>> +{
>>>>> +	unsigned int dcrs;
>>>>> +
>>>>> +	/* setup the dcr address mapping if it's in the device tree */
>>>>> +
>>>>> +	dcrs = dcr_resource_start(np, 0);
>>>>> +	if (dcrs != 0) {
>>>>> +		lp->sdma_dcrs = dcr_map(np, dcrs, dcr_resource_len(np,
>>> 0));
>>>>> +		lp->dma_in = temac_dma_dcr_in;
>>>>> +		lp->dma_out = temac_dma_dcr_out;
>>>>> +		dev_dbg(&op->dev, "DCR base: %x\n", dcrs);
>>>>> +		return 0;
>>>>> +	}
>>>>> +	/* no DCR in the device tree, indicate a failure */
>>>>> +	return -1;
>>>>> +}
>>>>> +
>>>>> +#else
>>>>> +
>>>>> +/*
>>>>> + * temac_dcr_setup - This is a stub for when DCR is not
> supported,
>>>>> + * such as with MicroBlaze
>>>>> + */
>>>>> +static int temac_dcr_setup(struct temac_local *lp, struct
> of_device
>>> *op,
>>>>> +				struct device_node *np)
>>>>> +{
>>>>> +	return -1;
>>>>> +}
>>>>> +
>>>>> +#endif
>>>>> +
>>>>> +/**
>>>>>   * temac_dma_bd_init - Setup buffer descriptor rings
>>>>>   */
>>>>>  static int temac_dma_bd_init(struct net_device *ndev)
>>>>> @@ -172,23 +238,23 @@ static int temac_dma_bd_init(struct
> net_device
>>> *ndev)
>>>>>  		lp->rx_bd_v[i].app0 = STS_CTRL_APP0_IRQONEND;
>>>>>  	}
>>>>>
>>>>> -	temac_dma_out32(lp, TX_CHNL_CTRL, 0x10220400 |
>>>>> +	lp->dma_out(lp, TX_CHNL_CTRL, 0x10220400 |
>>>>>  					  CHNL_CTRL_IRQ_EN |
>>>>>  					  CHNL_CTRL_IRQ_DLY_EN |
>>>>>  					  CHNL_CTRL_IRQ_COAL_EN);
>>>>>  	/* 0x10220483 */
>>>>>  	/* 0x00100483 */
>>>>> -	temac_dma_out32(lp, RX_CHNL_CTRL, 0xff010000 |
>>>>> +	lp->dma_out(lp, RX_CHNL_CTRL, 0xff010000 |
>>>>>  					  CHNL_CTRL_IRQ_EN |
>>>>>  					  CHNL_CTRL_IRQ_DLY_EN |
>>>>>  					  CHNL_CTRL_IRQ_COAL_EN |
>>>>>  					  CHNL_CTRL_IRQ_IOE);
>>>>>  	/* 0xff010283 */
>>>>>
>>>>> -	temac_dma_out32(lp, RX_CURDESC_PTR,  lp->rx_bd_p);
>>>>> -	temac_dma_out32(lp, RX_TAILDESC_PTR,
>>>>> +	lp->dma_out(lp, RX_CURDESC_PTR,  lp->rx_bd_p);
>>>>> +	lp->dma_out(lp, RX_TAILDESC_PTR,
>>>>>  		       lp->rx_bd_p + (sizeof(*lp->rx_bd_v) * (RX_BD_NUM
>>> - 1)));
>>>>> -	temac_dma_out32(lp, TX_CURDESC_PTR, lp->tx_bd_p);
>>>>> +	lp->dma_out(lp, TX_CURDESC_PTR, lp->tx_bd_p);
>>>>>
>>>>>  	return 0;
>>>>>  }
>>>>> @@ -426,9 +492,9 @@ static void temac_device_reset(struct
> net_device
>>> *ndev)
>>>>>  	temac_indirect_out32(lp, XTE_RXC1_OFFSET, val &
>>> ~XTE_RXC1_RXEN_MASK);
>>>>>  	/* Reset Local Link (DMA) */
>>>>> -	temac_dma_out32(lp, DMA_CONTROL_REG, DMA_CONTROL_RST);
>>>>> +	lp->dma_out(lp, DMA_CONTROL_REG, DMA_CONTROL_RST);
>>>>>  	timeout = 1000;
>>>>> -	while (temac_dma_in32(lp, DMA_CONTROL_REG) & DMA_CONTROL_RST) {
>>>>> +	while (lp->dma_in(lp, DMA_CONTROL_REG) & DMA_CONTROL_RST) {
>>>>>  		udelay(1);
>>>>>  		if (--timeout == 0) {
>>>>>  			dev_err(&ndev->dev,
>>>>> @@ -436,7 +502,7 @@ static void temac_device_reset(struct
> net_device
>>> *ndev)
>>>>>  			break;
>>>>>  		}
>>>>>  	}
>>>>> -	temac_dma_out32(lp, DMA_CONTROL_REG, DMA_TAIL_ENABLE);
>>>>> +	lp->dma_out(lp, DMA_CONTROL_REG, DMA_TAIL_ENABLE);
>>>>>
>>>>>  	temac_dma_bd_init(ndev);
>>>>>
>>>>> @@ -597,7 +663,7 @@ static int temac_start_xmit(struct sk_buff
> *skb,
>>> struct net_device *ndev)
>>>>>  		lp->tx_bd_tail = 0;
>>>>>
>>>>>  	/* Kick off the transfer */
>>>>> -	temac_dma_out32(lp, TX_TAILDESC_PTR, tail_p); /* DMA start */
>>>>> +	lp->dma_out(lp, TX_TAILDESC_PTR, tail_p); /* DMA start */
>>>>>
>>>>>  	return NETDEV_TX_OK;
>>>>>  }
>>>>> @@ -663,7 +729,7 @@ static void ll_temac_recv(struct net_device
>>> *ndev)
>>>>>  		cur_p = &lp->rx_bd_v[lp->rx_bd_ci];
>>>>>  		bdstat = cur_p->app0;
>>>>>  	}
>>>>> -	temac_dma_out32(lp, RX_TAILDESC_PTR, tail_p);
>>>>> +	lp->dma_out(lp, RX_TAILDESC_PTR, tail_p);
>>>>>
>>>>>  	spin_unlock_irqrestore(&lp->rx_lock, flags);
>>>>>  }
>>>>> @@ -674,8 +740,8 @@ static irqreturn_t ll_temac_tx_irq(int irq,
> void
>>> *_ndev)
>>>>>  	struct temac_local *lp = netdev_priv(ndev);
>>>>>  	unsigned int status;
>>>>>
>>>>> -	status = temac_dma_in32(lp, TX_IRQ_REG);
>>>>> -	temac_dma_out32(lp, TX_IRQ_REG, status);
>>>>> +	status = lp->dma_in(lp, TX_IRQ_REG);
>>>>> +	lp->dma_out(lp, TX_IRQ_REG, status);
>>>>>
>>>>>  	if (status & (IRQ_COAL | IRQ_DLY))
>>>>>  		temac_start_xmit_done(lp->ndev);
>>>>> @@ -692,8 +758,8 @@ static irqreturn_t ll_temac_rx_irq(int irq,
> void
>>> *_ndev)
>>>>>  	unsigned int status;
>>>>>
>>>>>  	/* Read and clear the status registers */
>>>>> -	status = temac_dma_in32(lp, RX_IRQ_REG);
>>>>> -	temac_dma_out32(lp, RX_IRQ_REG, status);
>>>>> +	status = lp->dma_in(lp, RX_IRQ_REG);
>>>>> +	lp->dma_out(lp, RX_IRQ_REG, status);
>>>>>
>>>>>  	if (status & (IRQ_COAL | IRQ_DLY))
>>>>>  		ll_temac_recv(lp->ndev);
>>>>> @@ -794,7 +860,7 @@ static ssize_t temac_show_llink_regs(struct
>>> device *dev,
>>>>>  	int i, len = 0;
>>>>>
>>>>>  	for (i = 0; i < 0x11; i++)
>>>>> -		len += sprintf(buf + len, "%.8x%s", temac_dma_in32(lp,
>>> i),
>>>>> +		len += sprintf(buf + len, "%.8x%s", lp->dma_in(lp, i),
>>>>>  			       (i % 8) == 7 ? "\n" : " ");
>>>>>  	len += sprintf(buf + len, "\n");
>>>>>
>>>>> @@ -820,7 +886,6 @@ temac_of_probe(struct of_device *op, const
>>> struct of_device_id *match)
>>>>>  	struct net_device *ndev;
>>>>>  	const void *addr;
>>>>>  	int size, rc = 0;
>>>>> -	unsigned int dcrs;
>>>>>
>>>>>  	/* Init network device structure */
>>>>>  	ndev = alloc_etherdev(sizeof(*lp));
>>>>> @@ -870,13 +935,20 @@ temac_of_probe(struct of_device *op, const
>>> struct of_device_id *match)
>>>>>  		goto nodev;
>>>>>  	}
>>>>>
>>>>> -	dcrs = dcr_resource_start(np, 0);
>>>>> -	if (dcrs == 0) {
>>>>> -		dev_err(&op->dev, "could not get DMA register
>>> address\n");
>>>>> -		goto nodev;
>>>>> +	/* Setup the DMA register accesses, could be DCR or memory
>>> mapped */
>>>>> +	if (temac_dcr_setup(lp, op, np)) {
>>>>> +
>>>>> +		/* no DCR in the device tree, try non-DCR */
>>>>> +		lp->sdma_regs = of_iomap(np, 0);
>>>>> +		if (lp->sdma_regs) {
>>>>> +			lp->dma_in = temac_dma_in32;
>>>>> +			lp->dma_out = temac_dma_out32;
>>>>> +			dev_dbg(&op->dev, "MEM base: %p\n",
>>> lp->sdma_regs);
>>>>> +		} else {
>>>>> +			dev_err(&op->dev, "unable to map DMA
>>> registers\n");
>>>>> +			goto nodev;
>>>>> +		}
>>>>>  	}
>>>>> -	lp->sdma_dcrs = dcr_map(np, dcrs, dcr_resource_len(np, 0));
>>>>> -	dev_dbg(&op->dev, "DCR base: %x\n", dcrs);
>>>>>
>>>>>  	lp->rx_irq = irq_of_parse_and_map(np, 0);
>>>>>  	lp->tx_irq = irq_of_parse_and_map(np, 1);
>>>> --
>>>> Michal Simek, Ing. (M.Eng)
>>>> PetaLogix - Linux Solutions for a Reconfigurable World
>>>> w: www.petalogix.com p: +61-7-30090663,+42-0-721842854 f:
>>> +61-7-30090663
>>>
>>>
>>> This email and any attachments are intended for the sole use of the
> named recipient(s) and
>> contain(s) confidential information that may be proprietary,
> privileged or copyrighted under
>> applicable law. If you are not the intended recipient, do not read,
> copy, or forward this email
>> message or any attachments. Delete this email message and any
> attachments immediately.
>>>
>>
>> --
>> Michal Simek, Ing. (M.Eng)
>> PetaLogix - Linux Solutions for a Reconfigurable World
>> w: www.petalogix.com p: +61-7-30090663,+42-0-721842854 f:
> +61-7-30090663
> 
> 
> This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately.
> 
> 


-- 
Michal Simek, Ing. (M.Eng)
PetaLogix - Linux Solutions for a Reconfigurable World
w: www.petalogix.com p: +61-7-30090663,+42-0-721842854 f: +61-7-30090663


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