Re: [dpdk-dev] [PATCH v3] i40e: workaround for X710 performance issues

["Zhang, Helin" <helin.zhang@intel.com>]

> -----Original Message-----
> From: Wu, Jingjing
> Sent: Thursday, January 8, 2015 10:44 AM
> To: Zhang, Helin; dev@dpdk.org
> Cc: Chen, Jing D; Liu, Jijiang; Cao, Waterman; Lu, Patrick; Rowden, Aaron F
> Subject: RE: [PATCH v3] i40e: workaround for X710 performance issues
> 
> 
> 
> > -----Original Message-----
> > From: Zhang, Helin
> > Sent: Tuesday, December 16, 2014 4:23 PM
> > To: dev@dpdk.org
> > Cc: Chen, Jing D; Wu, Jingjing; Liu, Jijiang; Cao, Waterman; Lu,
> > Patrick; Rowden, Aaron F; Zhang, Helin
> > Subject: [PATCH v3] i40e: workaround for X710 performance issues
> >
> > On X710, performance number is far from the expectation on recent
> > firmware versions. The fix for this issue may not be integrated in the
> > following firmware version. So the workaround in software driver is needed.
> > It needs to modify the initial values of 3 internal only registers.
> > Note that the workaround can be removed when it is fixed in firmware in the
> future.
> >
> > Signed-off-by: Helin Zhang <helin.zhang@intel.com>
> > ---
> >  lib/librte_pmd_i40e/i40e_ethdev.c | 89
> > +++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 89 insertions(+)
> >
> > v2 changes:
> > * Added a compile error fix.
> >
> > v3 changes:
> > * Used PRIx32 and PRIx64 instead for printing uint32_t and uint64_t
> >   variables.
> > * Re-worded annotations, and commit logs.
> >
> > diff --git a/lib/librte_pmd_i40e/i40e_ethdev.c
> > b/lib/librte_pmd_i40e/i40e_ethdev.c
> > index 008d62c..624f0ce 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 +444,16 @@ eth_i40e_dev_init(__rte_unused struct eth_driver
> > *eth_drv,
> >  	/* Clear PXE mode */
> >  	i40e_clear_pxe_mode(hw);
> >
> > +	/*
> > +	 * On X710, performance number is far from the expectation on
> > recent
> > +	 * firmware versions. The fix for this issue may not be integrated in
> > +	 * the following firmware version. So the workaround in software
> > driver
> > +	 * is needed. It needs to modify the initial values of 3 internal only
> > +	 * registers. Note that the workaround can be removed when it is
> > fixed
> > +	 * in firmware in the future.
> > +	 */
> > +	i40e_configure_registers(hw);
> > +
> >  	/* Get hw capabilities */
> >  	ret = i40e_get_cap(hw);
> >  	if (ret != I40E_SUCCESS) {
> > @@ -5294,3 +5305,81 @@ 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);
> > +
> 
> Do we need to add rte_le_to_cpu_64 here?
No, we don't need one more conversion, as 32 bits value are already 'cpu' byte order.

Thanks,
Helin

> 
> > +	return status;
> > +}
> > +
> > +/*
> > + * On X710, performance number is far from the expectation on recent
> > +firmware
> > + * versions. The fix for this issue may not be integrated in the
> > +following
> > + * firmware version. So the workaround in software driver is needed.
> > +It needs
> > + * to modify the initial values of 3 internal only registers. Note
> > +that the
> > + * workaround can be removed when it is fixed in firmware in the 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%"PRIx32,
> > +							reg_table[i].addr);
> > +			break;
> > +		}
> > +		PMD_DRV_LOG(DEBUG, "Read from 0x%"PRIx32":
> > 0x%"PRIx64,
> > +						reg_table[i].addr, reg);
> > +		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%"PRIx64" to
> > the "
> > +				"address of 0x%"PRIx32, reg_table[i].val,
> > +							reg_table[i].addr);
> > +			break;
> > +		}
> > +		PMD_DRV_LOG(DEBUG, "Write 0x%"PRIx64" to the address
> > of "
> > +			"0x%"PRIx32, reg_table[i].val, reg_table[i].addr);
> > +	}
> > +}
> > --
> > 1.8.1.4