[Skiboot] [PATCH v2] capi: Poll Err/Status register during CAPP recovery
Vaibhav Jain
vaibhav at linux.vnet.ibm.com
Fri Mar 16 13:40:58 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>
---
Changelog:
v2 -> Added an extra check for Bit(0) in Err/Status reg at the
beginning to check if recovery mode was entered. [Christophe]
---
hw/phb4.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 67 insertions(+), 17 deletions(-)
diff --git a/hw/phb4.c b/hw/phb4.c
index 47175df2..515b43e3 100644
--- a/hw/phb4.c
+++ b/hw/phb4.c
@@ -2857,25 +2857,74 @@ static int64_t load_capp_ucode(struct phb4 *p)
return rc;
}
-static void do_capp_recovery_scoms(struct phb4 *p)
+static int 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");
-
- offset = PHB4_CAPP_REG_OFFSET(p);
- /* disable snoops */
- xscom_write(p->chip_id, SNOOP_CAPI_CONFIG + offset, 0);
- load_capp_ucode(p);
- /* 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);
+ /* Get the status of CAPP recovery */
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);
+
+ /* No recovery in progress ignore */
+ if ((reg & PPC_BIT(0)) == 0) {
+ PHBDBG(p, "CAPP: No recovery in progress\n");
+ return 0;
+ }
+
+ PHBDBG(p, "CAPP: Waiting for recovery to complete\n");
+ /* recovery timer failure period 168ms */
+ end = mftb() + msecs_to_tb(168);
+ 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);
+
+ /* 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);
+
+ PHBDBG(p, "CAPP recovery complete\n");
+ } 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");
+
+ PHBDBG(p, "CAPP: Err/Status-reg=0x%016llx\n", reg);
+ rc = OPAL_HARDWARE;
+ }
+
+out:
+ return rc;
}
static int64_t phb4_creset(struct pci_slot *slot)
@@ -2934,8 +2983,9 @@ 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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