Re: [dpdk-dev] [PATCH v2] i40e: workaround for X710 performance issues

["Chen, Jing D" <jing.d.chen@intel.com>]

Hi Helin,

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Helin Zhang
> Sent: Monday, December 15, 2014 3:56 PM
> To: dev@dpdk.org
> Cc: Rowden, Aaron F
> Subject: [dpdk-dev] [PATCH v2] i40e: workaround for X710 performance
> issues
> 
> As the fixes of below performance issues on X710 may not be integrated
> in latest version of firmware, a workaround in software PMD is needed.
> It is to re-configure 3 specific registers after being initialized.
> - Cannot achieve line rate on X710.

packet size? 

> - Performance reduction when promiscuous mode is disabled.

You'd better add above descriptions in line with the code.

> Note that this workaround can be removed if the fixes are integrated
> in the firmware in future.
> 

I saw below code applied register setting in case it's 40G device. Can you give
more description on what device this patch would boost performance?
Will 10G fiber interface benefit from the change?

> Signed-off-by: Helin Zhang <helin.zhang@intel.com>
> ---
>  lib/librte_pmd_i40e/i40e_ethdev.c | 87
> +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 87 insertions(+)
> 
> v2 changes:
> * Added a compile error fix.
> 
> diff --git a/lib/librte_pmd_i40e/i40e_ethdev.c
> b/lib/librte_pmd_i40e/i40e_ethdev.c
> index 008d62c..82c072b 100644
> --- a/lib/librte_pmd_i40e/i40e_ethdev.c
> +++ b/lib/librte_pmd_i40e/i40e_ethdev.c
> @@ -198,6 +198,7 @@ static int i40e_dev_filter_ctrl(struct rte_eth_dev *dev,
>  				enum rte_filter_type filter_type,
>  				enum rte_filter_op filter_op,
>  				void *arg);
> +static void i40e_configure_registers(struct i40e_hw *hw);
> 
>  /* Default hash key buffer for RSS */
>  static uint32_t rss_key_default[I40E_PFQF_HKEY_MAX_INDEX + 1];
> @@ -443,6 +444,15 @@ eth_i40e_dev_init(__rte_unused struct eth_driver
> *eth_drv,
>  	/* Clear PXE mode */
>  	i40e_clear_pxe_mode(hw);
> 
> +	/*
> +	 * On X710, as old version of firmwares may have performance issues,
> +	 * 3 registers need to be re-configured with new values. And the
> latest
> +	 * version of firmware may not contain the fixes, workaround in SW
> +	 * driver is needed. This workaround can be removed when the fixes
> are
> +	 * integrated in firmware in future.
> +	 */
> +	i40e_configure_registers(hw);
> +
>  	/* Get hw capabilities */
>  	ret = i40e_get_cap(hw);
>  	if (ret != I40E_SUCCESS) {
> @@ -5294,3 +5304,80 @@ i40e_pctype_to_flowtype(enum
> i40e_filter_pctype pctype)
> 
>  	return flowtype_table[pctype];
>  }
> +
> +static int
> +i40e_debug_read_register(struct i40e_hw *hw, uint32_t addr, uint64_t
> *val)
> +{
> +	struct i40e_aq_desc desc;
> +	struct i40e_aqc_debug_reg_read_write *cmd =
> +		(struct i40e_aqc_debug_reg_read_write
> *)&desc.params.raw;
> +	enum i40e_status_code status;
> +
> +	i40e_fill_default_direct_cmd_desc(&desc,
> i40e_aqc_opc_debug_read_reg);
> +	cmd->address = rte_cpu_to_le_32(addr);
> +	status = i40e_asq_send_command(hw, &desc, NULL, 0, NULL);
> +	if (status < 0)
> +		return status;
> +
> +	*val = ((uint64_t)(rte_le_to_cpu_32(cmd->value_high)) <<
> (CHAR_BIT *
> +			sizeof(uint32_t))) + rte_le_to_cpu_32(cmd-
> >value_low);
> +
> +	return status;
> +}
> +
> +/*
> + * On X710, as old version of firmwares may have performance issues,
> + * 3 registers need to be re-configured with new values. And the latest
> version
> + * of firmware may not contain the fixes, workaround in SW driver is
> needed.
> + * This workaround can be removed when the fixes are integrated in
> firmware in
> + * future.
> + */
> +static void
> +i40e_configure_registers(struct i40e_hw *hw)
> +{
> +#define I40E_GL_SWR_PRI_JOIN_MAP_0       0x26CE00
> +#define I40E_GL_SWR_PRI_JOIN_MAP_2       0x26CE08
> +#define I40E_GL_SWR_PM_UP_THR            0x269FBC
> +#define I40E_GL_SWR_PRI_JOIN_MAP_0_VALUE 0x10000200
> +#define I40E_GL_SWR_PRI_JOIN_MAP_2_VALUE 0x011f0200
> +#define I40E_GL_SWR_PM_UP_THR_VALUE      0x03030303
> +
> +	static const struct {
> +		uint32_t addr;
> +		uint64_t val;
> +	} reg_table[] = {
> +		{I40E_GL_SWR_PRI_JOIN_MAP_0,
> I40E_GL_SWR_PRI_JOIN_MAP_0_VALUE},
> +		{I40E_GL_SWR_PRI_JOIN_MAP_2,
> I40E_GL_SWR_PRI_JOIN_MAP_2_VALUE},
> +		{I40E_GL_SWR_PM_UP_THR,
> I40E_GL_SWR_PM_UP_THR_VALUE},
> +	};
> +	uint64_t reg;
> +	uint32_t i;
> +	int ret;
> +
> +	/* Below fix is for X710 only */
> +	if (i40e_is_40G_device(hw->device_id))
> +		return;
> +
> +	for (i = 0; i < RTE_DIM(reg_table); i++) {
> +		ret = i40e_debug_read_register(hw, reg_table[i].addr, &reg);
> +		if (ret < 0) {
> +			PMD_DRV_LOG(ERR, "Failed to read from 0x%x\n",
> +						reg_table[i].addr);
> +			break;
> +		}
> +		PMD_DRV_LOG(DEBUG, "Read from 0x%x: 0x%lx",
> reg_table[i].addr,
> +									reg);

PRIu64?

> +		if (reg == reg_table[i].val)
> +			continue;
> +
> +		ret = i40e_aq_debug_write_register(hw, reg_table[i].addr,
> +						reg_table[i].val, NULL);
> +		if (ret < 0) {
> +			PMD_DRV_LOG(ERR, "Failed to write 0x%lx to
> 0x%x\n",
> +				reg_table[i].val, reg_table[i].addr);

PRIu64?

> +			break;
> +		}
> +		PMD_DRV_LOG(DEBUG, "Write to 0x%x: 0x%lx",
> reg_table[i].addr,
> +							reg_table[i].val);

PRIu64?

> +	}
> +}

I saw some wrong code alignment above, but not sure how it looks like on 
terminal, please double check.

> --
> 1.8.1.4