[Skiboot] [PATCH] capi: Poll Err/Status register during CAPP recovery
Vaibhav Jain
vaibhav at linux.vnet.ibm.com
Mon Jan 22 17:08:12 AEDT 2018
This patch updates do_capp_recovery_scoms() to poll the CAPP
Err/Status control register, check for CAPP-Recovery to
complete/fail based on indications of BITS-1,5,9 and then proceed with
the CAPP-Recovery scoms iif recovery completed successfully. This would
prevent cases where we bring-up the PCIe link while recovery sequencer
on CAPP is still busy with casting out cache lines.
In case CAPP-Recovery didn't complete successfully an error is returned
from do_capp_recovery_scoms() asking phb4_creset() to keep the phb4
fenced and mark it as broken.
The loop that implements polling of Err/Status register will also log
an error on the PHB when it continues for more than 168ms which is the
max time to failure for CAPP-Recovery.
Signed-off-by: Vaibhav Jain <vaibhav at linux.vnet.ibm.com>
---
This patch is based on an earlier patch "capi: Perform capp recovery
sequence only when PBCQ is idle" available at
http://patchwork.ozlabs.org/patch/862771/
---
hw/phb4.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--------
1 file changed, 54 insertions(+), 8 deletions(-)
diff --git a/hw/phb4.c b/hw/phb4.c
index 93ed1e06..23f923d7 100644
--- a/hw/phb4.c
+++ b/hw/phb4.c
@@ -2829,25 +2829,70 @@ static int64_t load_capp_ucode(struct phb4 *p)
return rc;
}
-static void do_capp_recovery_scoms(struct phb4 *p)
+static int64_t do_capp_recovery_scoms(struct phb4 *p)
{
- uint64_t reg;
- uint32_t offset;
+ uint64_t rc, reg, end;
+ uint64_t offset = PHB4_CAPP_REG_OFFSET(p);
- PHBDBG(p, "Doing CAPP recovery scoms\n");
+ PHBDBG(p, "CAPP: Waiting for recovery to complete\n");
- offset = PHB4_CAPP_REG_OFFSET(p);
+ /* recovery timer failure period 168ms */
+ end = mftb() + msecs_to_tb(168);
+ xscom_read(p->chip_id, CAPP_ERR_STATUS_CTRL + offset, ®);
+ while ((reg & (PPC_BIT(1) | PPC_BIT(5) | PPC_BIT(9))) == 0) {
+
+ time_wait_ms(5);
+ xscom_read(p->chip_id, CAPP_ERR_STATUS_CTRL + offset, ®);
+
+ if (end && tb_compare(mftb(), end) != TB_AAFTERB) {
+ PHBERR(p, "CAPP: Capp recovery Timed-out.\n");
+ end = 0;
+ }
+ }
+
+ /* Check if the recovery failed or passed */
+ if (reg & PPC_BIT(1)) {
+ PHBDBG(p, "Doing CAPP recovery scoms\n");
/* disable snoops */
xscom_write(p->chip_id, SNOOP_CAPI_CONFIG + offset, 0);
- load_capp_ucode(p);
+ rc = load_capp_ucode(p);
+
+ if (rc) {
+ PHBERR(p, "CAPP: Unable to reload ucode\n");
+ goto out;
+ }
+
/* clear err rpt reg*/
xscom_write(p->chip_id, CAPP_ERR_RPT_CLR + offset, 0);
+
/* clear capp fir */
xscom_write(p->chip_id, CAPP_FIR + offset, 0);
+ /* Just reset Bit-0,1 and dont touch any other bit */
xscom_read(p->chip_id, CAPP_ERR_STATUS_CTRL + offset, ®);
reg &= ~(PPC_BIT(0) | PPC_BIT(1));
xscom_write(p->chip_id, CAPP_ERR_STATUS_CTRL + offset, reg);
+
+ } else {
+
+ /* We will checkstop here due to FIR ACTION for
+ * failed recovery. So this message would never be logged.
+ * But if we still enter here then return an error forcing a
+ * fence of the PHB.
+ */
+ if (reg & PPC_BIT(5))
+ PHBERR(p, "CAPP: Capp recovery Failed\n");
+ else if (reg & PPC_BIT(9))
+ PHBERR(p, "CAPP: Capp recovery hang detected\n");
+ else
+ PHBERR(p, "CAPP: Unknown recovery failure\n");
+
+ PHBDGB("CAPP: Err/Status-reg=0x%016llx\n", reg);
+ rc = OPAL_HARDWARE;
+ }
+
+out:
+ return rc;
}
static int64_t phb4_creset(struct pci_slot *slot)
@@ -2906,8 +2951,9 @@ static int64_t phb4_creset(struct pci_slot *slot)
PHBDBG(p, "CRESET: No pending transactions\n");
/* capp recovery */
- if (p->flags & PHB4_CAPP_RECOVERY)
- do_capp_recovery_scoms(p);
+ if (p->flags & PHB4_CAPP_RECOVERY &&
+ do_capp_recovery_scoms(p))
+ goto error;
/* Clear errors in PFIR and NFIR */
xscom_write(p->chip_id, p->pci_stk_xscom + 0x1,
--
2.14.3
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