[dpdk-dev,3/5] i40e: support selecting hash functions
diff mbox

Message ID 1406184149-11531-4-git-send-email-helin.zhang@intel.com
State Superseded, archived
Headers show

Commit Message

Helin Zhang July 24, 2014, 6:42 a.m. UTC
Toeplitz and simple XOR hash functions are supported by
hardware, code changes are to tell the hardware which hash
function is selected according to the configuration.

Signed-off-by: Helin Zhang <helin.zhang@intel.com>
---
 config/common_bsdapp              |  1 +
 config/common_linuxapp            |  1 +
 lib/librte_pmd_i40e/i40e_ethdev.c | 30 ++++++++++++++++++++++++++++++
 3 files changed, 32 insertions(+)

Comments

Thomas Monjalon July 24, 2014, 7:59 a.m. UTC | #1
2014-07-24 14:42, Helin Zhang:
> Toeplitz and simple XOR hash functions are supported by
> hardware, code changes are to tell the hardware which hash
> function is selected according to the configuration.
> 
> Signed-off-by: Helin Zhang <helin.zhang@intel.com>

> +CONFIG_RTE_LIBRTE_I40E_HASH_FUNC_TOEPLITZ=y

Is it really a good idea to configure this kind of thing at build time?
Maybe yes, I'm not sure.
Matthew Hall July 24, 2014, 8:01 a.m. UTC | #2
On Thu, Jul 24, 2014 at 09:59:23AM +0200, Thomas Monjalon wrote:
> Is it really a good idea to configure this kind of thing at build time?
> Maybe yes, I'm not sure.

Whether it's safe to set at runtime probably depends what happens to the card 
if it gets changed. Do you have to reset the card or the port? Or is it OK if 
it's more dynamic?

Matthew.
Thomas Monjalon July 24, 2014, 8:07 a.m. UTC | #3
2014-07-24 01:01, Matthew Hall:
> On Thu, Jul 24, 2014 at 09:59:23AM +0200, Thomas Monjalon wrote:
> > Is it really a good idea to configure this kind of thing at build time?
> > Maybe yes, I'm not sure.
> 
> Whether it's safe to set at runtime probably depends what happens to the card 
> if it gets changed. Do you have to reset the card or the port? Or is it OK if 
> it's more dynamic?

No, we can change configuration with rte_eth_dev_configure() before
initializing port. So it is truly configurable.
Requiring recompilation means it's not really configurable between 2 runs.
And it breaks binary packaging for Linux distributions.

Many things in DPDK are configured at build time. But we should wonder if
it's really a good design.
Matthew Hall July 24, 2014, 8:14 a.m. UTC | #4
If no reboot of the card is needed then it's probably better to add it to one of the ethtool style APIs...
Helin Zhang July 24, 2014, 8:54 a.m. UTC | #5
> -----Original Message-----

> From: Matthew Hall [mailto:mhall@mhcomputing.net]

> Sent: Thursday, July 24, 2014 4:15 PM

> To: Thomas Monjalon; Zhang, Helin

> Cc: dev@dpdk.org

> Subject: Re: [dpdk-dev] [PATCH 3/5] i40e: support selecting hash functions

> 

> If no reboot of the card is needed then it's probably better to add it to one of

> the ethtool style APIs...

> --

> Sent from my mobile device.

> 

> On July 24, 2014 1:07:37 AM PDT, Thomas Monjalon

> <thomas.monjalon@6wind.com> wrote:

> >2014-07-24 01:01, Matthew Hall:

> >> On Thu, Jul 24, 2014 at 09:59:23AM +0200, Thomas Monjalon wrote:

> >> > Is it really a good idea to configure this kind of thing at build

> >time?

> >> > Maybe yes, I'm not sure.

> >>

> >> Whether it's safe to set at runtime probably depends what happens to

> >the card

> >> if it gets changed. Do you have to reset the card or the port? Or is

> >it OK if

> >> it's more dynamic?

> >

> >No, we can change configuration with rte_eth_dev_configure() before

> >initializing port. So it is truly configurable.

> >Requiring recompilation means it's not really configurable between 2

> >runs.

> >And it breaks binary packaging for Linux distributions.

> >

> >Many things in DPDK are configured at build time. But we should wonder

> >if it's really a good design.



Hi Thomas, Matt

Good points! Thank you guys!

Regards,
Helin

Patch
diff mbox

diff --git a/config/common_bsdapp b/config/common_bsdapp
index bf6d8a0..e73629e 100644
--- a/config/common_bsdapp
+++ b/config/common_bsdapp
@@ -187,6 +187,7 @@  CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC=n
 CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_VF=4
 # interval up to 8160 us, aligned to 2 (or default value)
 CONFIG_RTE_LIBRTE_I40E_ITR_INTERVAL=-1
+CONFIG_RTE_LIBRTE_I40E_HASH_FUNC_TOEPLITZ=y
 
 #
 # Compile burst-oriented VIRTIO PMD driver
diff --git a/config/common_linuxapp b/config/common_linuxapp
index 9047975..9e00513 100644
--- a/config/common_linuxapp
+++ b/config/common_linuxapp
@@ -210,6 +210,7 @@  CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC=n
 CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_VF=4
 # interval up to 8160 us, aligned to 2 (or default value)
 CONFIG_RTE_LIBRTE_I40E_ITR_INTERVAL=-1
+CONFIG_RTE_LIBRTE_I40E_HASH_FUNC_TOEPLITZ=y
 
 #
 # Compile burst-oriented VIRTIO PMD driver
diff --git a/lib/librte_pmd_i40e/i40e_ethdev.c b/lib/librte_pmd_i40e/i40e_ethdev.c
index 9ed31b5..cc04c70 100644
--- a/lib/librte_pmd_i40e/i40e_ethdev.c
+++ b/lib/librte_pmd_i40e/i40e_ethdev.c
@@ -203,6 +203,7 @@  static int i40e_dev_rss_hash_update(struct rte_eth_dev *dev,
 				    struct rte_eth_rss_conf *rss_conf);
 static int i40e_dev_rss_hash_conf_get(struct rte_eth_dev *dev,
 				      struct rte_eth_rss_conf *rss_conf);
+static void i40e_select_hash_function(struct i40e_hw *hw);
 
 /* Default hash key buffer for RSS */
 static uint32_t rss_key_default[I40E_PFQF_HKEY_MAX_INDEX + 1];
@@ -384,6 +385,9 @@  eth_i40e_dev_init(__rte_unused struct eth_driver *eth_drv,
 		return ret;
 	}
 
+	/* Select hash functions */
+	i40e_select_hash_function(hw);
+
 	/* Initialize the shared code (base driver) */
 	ret = i40e_init_shared_code(hw);
 	if (ret) {
@@ -3956,3 +3960,29 @@  i40e_pf_config_mq_rx(struct i40e_pf *pf)
 
 	return 0;
 }
+
+static void
+i40e_select_hash_function(struct i40e_hw *hw)
+{
+	uint32_t reg;
+
+	reg = I40E_READ_REG(hw, I40E_GLQF_CTL);
+#ifdef RTE_LIBRTE_I40E_HASH_FUNC_TOEPLITZ
+	if (reg & I40E_GLQF_CTL_HTOEP_MASK) {
+		PMD_DRV_LOG(DEBUG, "Hash function already set to Hoeplitz\n");
+		return;
+	}
+	reg |= I40E_GLQF_CTL_HTOEP_MASK;
+#else
+	if (!(reg & I40E_GLQF_CTL_HTOEP_MASK)) {
+		PMD_DRV_LOG(DEBUG, "Hash function already set to "
+						"Simple XOR\n");
+		return;
+	}
+	reg &= ~I40E_GLQF_CTL_HTOEP_MASK;
+#endif
+	PMD_DRV_LOG(INFO, "Hash function set to %s\n",
+		(reg & I40E_GLQF_CTL_HTOEP_MASK) ? "Toeplitz" : "XOR");
+	I40E_WRITE_REG(hw, I40E_GLQF_CTL, reg);
+	I40E_WRITE_FLUSH(hw);
+}