d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

e1000: fix I219 hang on reset

Browse Source 
Clear the rings before reset to avoid a HW hang.

Inspired by em-7.7.8 and DPDK (1fc9701238edcf0541289b9ae15565b6d9d7ab30)

Reviewed by:	erj
MFC after:	2 weeks
Sponsored by:	BBOX.io
Pull Request:	https://github.com/freebsd/freebsd-src/pull/540
This commit is contained in:
Kevin Bowling 2023-02-08 12:21:45 -07:00
parent 89a072d11c
commit ae1dca798e
1 changed files with 117 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

119
sys/dev/e1000/if_em.c
View File

@ -351,6 +351,7 @@ static int em_get_regs(SYSCTL_HANDLER_ARGS);
static void lem_smartspeed(struct e1000_softc *);
static void igb_configure_queues(struct e1000_softc *);
static void em_flush_desc_rings(struct e1000_softc *);
/*********************************************************************
@ -1913,6 +1914,10 @@ em_if_stop(if_ctx_t ctx)
INIT_DEBUGOUT("em_if_stop: begin");
/* I219 needs special flushing to avoid hangs */
if (sc->hw.mac.type >= e1000_pch_spt && sc->hw.mac.type < igb_mac_min)
em_flush_desc_rings(sc);
e1000_reset_hw(&sc->hw);
if (sc->hw.mac.type >= e1000_82544)
E1000_WRITE_REG(&sc->hw, E1000_WUFC, 0);
@ -1978,8 +1983,7 @@ em_allocate_pci_resources(if_ctx_t ctx)
sc->hw.hw_addr = (u8 *)&sc->osdep.mem_bus_space_handle;
/* Only older adapters use IO mapping */
if (sc->hw.mac.type < em_mac_min &&
sc->hw.mac.type > e1000_82543) {
if (sc->hw.mac.type < em_mac_min && sc->hw.mac.type > e1000_82543) {
/* Figure our where our IO BAR is ? */
for (rid = PCIR_BAR(0); rid < PCIR_CIS;) {
val = pci_read_config(dev, rid, 4);
@ -2467,6 +2471,113 @@ igb_init_dmac(struct e1000_softc *sc, u32 pba)
E1000_WRITE_REG(hw, E1000_DMACR, 0);
}
}
/*********************************************************************
* The 3 following flush routines are used as a workaround in the
* I219 client parts and only for them.
*
* em_flush_tx_ring - remove all descriptors from the tx_ring
*
* We want to clear all pending descriptors from the TX ring.
* zeroing happens when the HW reads the regs. We assign the ring itself as
* the data of the next descriptor. We don't care about the data we are about
* to reset the HW.
**********************************************************************/
static void
em_flush_tx_ring(struct e1000_softc *sc)
{
struct e1000_hw *hw = &sc->hw;
struct tx_ring *txr = &sc->tx_queues->txr;
struct e1000_tx_desc *txd;
u32 tctl, txd_lower = E1000_TXD_CMD_IFCS;
u16 size = 512;
tctl = E1000_READ_REG(hw, E1000_TCTL);
E1000_WRITE_REG(hw, E1000_TCTL, tctl | E1000_TCTL_EN);
txd = &txr->tx_base[txr->tx_cidx_processed];
/* Just use the ring as a dummy buffer addr */
txd->buffer_addr = txr->tx_paddr;
txd->lower.data = htole32(txd_lower | size);
txd->upper.data = 0;
/* flush descriptors to memory before notifying the HW */
wmb();
E1000_WRITE_REG(hw, E1000_TDT(0), txr->tx_cidx_processed);
mb();
usec_delay(250);
}
/*********************************************************************
* em_flush_rx_ring - remove all descriptors from the rx_ring
*
* Mark all descriptors in the RX ring as consumed and disable the rx ring
**********************************************************************/
static void
em_flush_rx_ring(struct e1000_softc *sc)
{
struct e1000_hw *hw = &sc->hw;
u32 rctl, rxdctl;
rctl = E1000_READ_REG(hw, E1000_RCTL);
E1000_WRITE_REG(hw, E1000_RCTL, rctl & ~E1000_RCTL_EN);
E1000_WRITE_FLUSH(hw);
usec_delay(150);
rxdctl = E1000_READ_REG(hw, E1000_RXDCTL(0));
/* zero the lower 14 bits (prefetch and host thresholds) */
rxdctl &= 0xffffc000;
/*
* update thresholds: prefetch threshold to 31, host threshold to 1
* and make sure the granularity is "descriptors" and not "cache lines"
*/
rxdctl |= (0x1F | (1 << 8) | E1000_RXDCTL_THRESH_UNIT_DESC);
E1000_WRITE_REG(hw, E1000_RXDCTL(0), rxdctl);
/* momentarily enable the RX ring for the changes to take effect */
E1000_WRITE_REG(hw, E1000_RCTL, rctl | E1000_RCTL_EN);
E1000_WRITE_FLUSH(hw);
usec_delay(150);
E1000_WRITE_REG(hw, E1000_RCTL, rctl & ~E1000_RCTL_EN);
}
/*********************************************************************
* em_flush_desc_rings - remove all descriptors from the descriptor rings
*
* In I219, the descriptor rings must be emptied before resetting the HW
* or before changing the device state to D3 during runtime (runtime PM).
*
* Failure to do this will cause the HW to enter a unit hang state which can
* only be released by PCI reset on the device
*
**********************************************************************/
static void
em_flush_desc_rings(struct e1000_softc *sc)
{
struct e1000_hw *hw = &sc->hw;
device_t dev = sc->dev;
u16 hang_state;
u32 fext_nvm11, tdlen;
/* First, disable MULR fix in FEXTNVM11 */
fext_nvm11 = E1000_READ_REG(hw, E1000_FEXTNVM11);
fext_nvm11 |= E1000_FEXTNVM11_DISABLE_MULR_FIX;
E1000_WRITE_REG(hw, E1000_FEXTNVM11, fext_nvm11);
/* do nothing if we're not in faulty state, or if the queue is empty */
tdlen = E1000_READ_REG(hw, E1000_TDLEN(0));
hang_state = pci_read_config(dev, PCICFG_DESC_RING_STATUS, 2);
if (!(hang_state & FLUSH_DESC_REQUIRED) || !tdlen)
return;
em_flush_tx_ring(sc);
/* recheck, maybe the fault is caused by the rx ring */
hang_state = pci_read_config(dev, PCICFG_DESC_RING_STATUS, 2);
if (hang_state & FLUSH_DESC_REQUIRED)
em_flush_rx_ring(sc);
}
/*********************************************************************
*
@ -2698,6 +2809,10 @@ em_reset(if_ctx_t ctx)
break;
}
/* I219 needs some special flushing to avoid hangs */
if (sc->hw.mac.type >= e1000_pch_spt && sc->hw.mac.type < igb_mac_min)
em_flush_desc_rings(sc);
/* Issue a global reset */
e1000_reset_hw(hw);
if (hw->mac.type >= igb_mac_min) {