[src/trunk]: src/sys/dev/pci Modify (E)ITR, TIDV and TADV related code:

[msaitoh <msaitoh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/9e7531506307
branches:  trunk
changeset: 808094:9e7531506307
user:      msaitoh <msaitoh%NetBSD.org@localhost>
date:      Mon May 04 08:46:09 2015 +0000

description:
Modify (E)ITR, TIDV and TADV related code:
 - ITR regiser are not documented in 82575 and newer devices'
   manual. The documets say "E"ITR(0) has no alias (to old ITR).
   But in reality, the alias really exists. When EITR(0) is
   written, the old ITR is changed. Before this commit, ITR was
   written after EITR was written. It causes that EITR's value
   (450) was overwritten with old ITR(1500). Set sc_itr first
   and use the value and don't set ITR if a device >= 82575
   (which has MSI-X multi queue function).
 - Older than 82540 devices have no TADV register.
 - 82575 and newer devices have no TIDV and TADV registers.

diffstat:

 sys/dev/pci/if_wm.c |  66 +++++++++++++++++++++++++++++++++-------------------
 1 files changed, 42 insertions(+), 24 deletions(-)

diffs (117 lines):

diff -r 83bc0ce976ec -r 9e7531506307 sys/dev/pci/if_wm.c
--- a/sys/dev/pci/if_wm.c       Mon May 04 08:16:28 2015 +0000
+++ b/sys/dev/pci/if_wm.c       Mon May 04 08:46:09 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_wm.c,v 1.318 2015/05/04 06:51:08 msaitoh Exp $      */
+/*     $NetBSD: if_wm.c,v 1.319 2015/05/04 08:46:09 msaitoh Exp $      */
 
 /*
  * Copyright (c) 2001, 2002, 2003, 2004 Wasabi Systems, Inc.
@@ -81,7 +81,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.318 2015/05/04 06:51:08 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.319 2015/05/04 08:46:09 msaitoh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_net_mpsafe.h"
@@ -3951,6 +3951,32 @@
        if (sc->sc_flags & WM_F_HAS_MII)
                wm_gmii_reset(sc);
 
+       /* Calculate (E)ITR value */
+       if ((sc->sc_flags & WM_F_NEWQUEUE) != 0) {
+               sc->sc_itr = 450;       /* For EITR */
+       } else if (sc->sc_type >= WM_T_82543) {
+               /*
+                * Set up the interrupt throttling register (units of 256ns)
+                * Note that a footnote in Intel's documentation says this
+                * ticker runs at 1/4 the rate when the chip is in 100Mbit
+                * or 10Mbit mode.  Empirically, it appears to be the case
+                * that that is also true for the 1024ns units of the other
+                * interrupt-related timer registers -- so, really, we ought
+                * to divide this value by 4 when the link speed is low.
+                *
+                * XXX implement this division at link speed change!
+                */
+
+               /*
+                * For N interrupts/sec, set this value to:
+                * 1000000000 / (N * 256).  Note that we set the
+                * absolute and packet timer values to this value
+                * divided by 4 to get "simple timer" behavior.
+                */
+
+               sc->sc_itr = 1500;              /* 2604 ints/sec */
+       }
+
        /* Initialize the transmit descriptor ring. */
        memset(sc->sc_txdescs, 0, WM_TXDESCSIZE(sc));
        WM_CDTXSYNC(sc, 0, WM_NTXDESC(sc),
@@ -3970,8 +3996,6 @@
                CSR_WRITE(sc, WMREG_TDBAL, WM_CDTXADDR_LO(sc, 0));
                CSR_WRITE(sc, WMREG_TDLEN, WM_TXDESCSIZE(sc));
                CSR_WRITE(sc, WMREG_TDH, 0);
-               CSR_WRITE(sc, WMREG_TIDV, 375);         /* ITR / 4 */
-               CSR_WRITE(sc, WMREG_TADV, 375);         /* should be same */
 
                if ((sc->sc_flags & WM_F_NEWQUEUE) != 0)
                        /*
@@ -3982,6 +4006,13 @@
                            | TXDCTL_PTHRESH(0) | TXDCTL_HTHRESH(0)
                            | TXDCTL_WTHRESH(0));
                else {
+                       /* ITR / 4 */
+                       CSR_WRITE(sc, WMREG_TIDV, sc->sc_itr / 4);
+                       if (sc->sc_type >= WM_T_82540) {
+                               /* should be same */
+                               CSR_WRITE(sc, WMREG_TADV, sc->sc_itr / 4);
+                       }
+
                        CSR_WRITE(sc, WMREG_TDT, 0);
                        CSR_WRITE(sc, WMREG_TXDCTL(0), TXDCTL_PTHRESH(0) |
                            TXDCTL_HTHRESH(0) | TXDCTL_WTHRESH(0));
@@ -4019,8 +4050,8 @@
                CSR_WRITE(sc, WMREG_RDBAH, WM_CDRXADDR_HI(sc, 0));
                CSR_WRITE(sc, WMREG_RDBAL, WM_CDRXADDR_LO(sc, 0));
                CSR_WRITE(sc, WMREG_RDLEN, sizeof(sc->sc_rxdescs));
+
                if ((sc->sc_flags & WM_F_NEWQUEUE) != 0) {
-                       CSR_WRITE(sc, WMREG_EITR(0), 450);
                        if (MCLBYTES & ((1 << SRRCTL_BSIZEPKT_SHIFT) - 1))
                                panic("%s: MCLBYTES %d unsupported for i2575 or higher\n", __func__, MCLBYTES);
                        CSR_WRITE(sc, WMREG_SRRCTL, SRRCTL_DESCTYPE_LEGACY
@@ -4182,26 +4213,13 @@
 
        if (sc->sc_type >= WM_T_82543) {
                /*
-                * Set up the interrupt throttling register (units of 256ns)
-                * Note that a footnote in Intel's documentation says this
-                * ticker runs at 1/4 the rate when the chip is in 100Mbit
-                * or 10Mbit mode.  Empirically, it appears to be the case
-                * that that is also true for the 1024ns units of the other
-                * interrupt-related timer registers -- so, really, we ought
-                * to divide this value by 4 when the link speed is low.
-                *
-                * XXX implement this division at link speed change!
+                * XXX 82574 has both ITR and EITR. SET EITR when we use
+                * the multi queue function with MSI-X.
                 */
-
-               /*
-                * For N interrupts/sec, set this value to:
-                * 1000000000 / (N * 256).  Note that we set the
-                * absolute and packet timer values to this value
-                * divided by 4 to get "simple timer" behavior.
-                */
-
-               sc->sc_itr = 1500;              /* 2604 ints/sec */
-               CSR_WRITE(sc, WMREG_ITR, sc->sc_itr);
+               if ((sc->sc_flags & WM_F_NEWQUEUE) != 0)
+                       CSR_WRITE(sc, WMREG_EITR(0), sc->sc_itr);
+               else
+                       CSR_WRITE(sc, WMREG_ITR, sc->sc_itr);
        }
 
        /* Set the VLAN ethernetype. */