[Skiboot] [RFC 2/2] hw/phb3: disable CAPI mode during complete reset
Andrew Donnellan
andrew.donnellan at au1.ibm.com
Fri Sep 16 20:22:48 AEST 2016
When fast rebooting or kexec-ing a system with a PHB in CAPI mode, we need
to return the PHB to regular PCIe mode.
In order to do this, we have to reset a bunch of registers to their
pre-CAPI-mode state. However, doing this while there is traffic going over
the PCI link is dangerous and will generally cause a checkstop.
As such, we want to do this while the PHB is fenced. Conveniently, during a
complete reset we force a PHB fence, so this is a good opportunity to
disable CAPI mode.
When doing a complete reset, if the PHB is in CAPI mode, execute a sequence
of SCOMs to reset PHB-related registers back to their regular, PCIe mode
values.
Signed-off-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>
---
hw/phb3.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++-
include/phb3.h | 9 ++--
2 files changed, 126 insertions(+), 4 deletions(-)
diff --git a/hw/phb3.c b/hw/phb3.c
index 4425522..5f229da 100644
--- a/hw/phb3.c
+++ b/hw/phb3.c
@@ -39,6 +39,7 @@
#undef DISABLE_ERR_INTS
static void phb3_init_hw(struct phb3 *p, bool first_init);
+static int64_t disable_capi_mode(struct phb3 *p);
#define PHBDBG(p, fmt, a...) prlog(PR_DEBUG, "PHB#%04x: " fmt, \
(p)->phb.opal_id, ## a)
@@ -2437,6 +2438,10 @@ static int64_t phb3_creset(struct pci_slot *slot)
if (!phb3_fenced(p))
xscom_write(p->chip_id, p->pe_xscom + 0x2, 0x000000f000000000ull);
+ /* Now that we're guaranteed to be fenced, disable CAPI mode */
+ if (!(p->flags & PHB3_CAPP_RECOVERY))
+ disable_capi_mode(p);
+
/* Clear errors in NFIR and raise ETU reset */
xscom_read(p->chip_id, p->pe_xscom + 0x0, &p->nfir_cache);
@@ -2476,6 +2481,11 @@ static int64_t phb3_creset(struct pci_slot *slot)
p->flags &= ~PHB3_CAPP_RECOVERY;
phb3_init_hw(p, false);
+ if (p->flags & PHB3_CAPP_DISABLING) {
+ do_capp_recovery_scoms(p);
+ p->flags &= ~PHB3_CAPP_DISABLING;
+ }
+
pci_slot_set_state(slot, PHB3_SLOT_CRESET_FRESET);
return pci_slot_set_sm_timeout(slot, msecs_to_tb(100));
case PHB3_SLOT_CRESET_FRESET:
@@ -3435,6 +3445,117 @@ static int64_t phb3_get_capi_mode(struct phb *phb)
return ret;
}
+/*
+ * Disable CAPI mode on a PHB.
+ *
+ * Must be done while PHB is fenced and in recovery. Leaves CAPP in recovery -
+ * we can't come out of recovery until the PHB has been reinitialised.
+ *
+ * We don't reset generic error registers here - we rely on phb3_init_hw() to
+ * do that.
+ *
+ * Sets PHB3_CAPP_DISABLING flag when complete.
+ */
+static int64_t disable_capi_mode(struct phb3 *p)
+{
+ struct proc_chip *chip = get_chip(p->chip_id);
+ uint64_t reg;
+ uint32_t offset = PHB3_CAPP_REG_OFFSET(p);
+
+ lock(&capi_lock);
+
+ xscom_read(p->chip_id, PE_CAPP_EN + PE_REG_OFFSET(p), ®);
+ if (!(reg & PPC_BIT(0))) {
+ /* Not in CAPI mode, no action required */
+ unlock(&capi_lock);
+ return OPAL_SUCCESS;
+ }
+
+ PHBDBG(p, "CAPP: Disabling CAPI mode\n");
+ if (!(chip->capp_phb3_attached_mask & (1 << p->index)))
+ PHBINF(p, "CAPP: WARNING: may not be attached!\n");
+
+ /* CAPP Error Status and Control Register - disable TLBI */
+ xscom_read(p->chip_id, CAPP_ERR_STATUS_CTRL + offset, ®);
+ reg |= PPC_BIT(0);
+ xscom_write(p->chip_id, CAPP_ERR_STATUS_CTRL + offset, reg);
+
+ /* Snoop CAPI Configuration Register - disable snooping */
+ xscom_write(p->chip_id, SNOOP_CAPI_CONFIG + offset,
+ 0x0000000000000000);
+
+ /* APC Master PB Control Register - disable examining cResps */
+ xscom_read(p->chip_id, APC_MASTER_PB_CTRL + offset, ®);
+ reg &= ~PPC_BIT(3);
+ xscom_write(p->chip_id, APC_MASTER_PB_CTRL + offset, reg);
+
+ /* APC Master Config Register - de-select PHBs */
+ xscom_read(p->chip_id, APC_MASTER_CAPI_CTRL + offset, ®);
+ reg &= ~PPC_BITMASK(1, 3);
+ xscom_write(p->chip_id, APC_MASTER_CAPI_CTRL + offset, reg);
+
+ /* PE Bus AIB Mode Bits */
+ xscom_read(p->chip_id, p->pci_xscom + 0xf, ®);
+ reg |= PPC_BITMASK(7, 8); /* Ch2 command credit */
+ reg &= ~PPC_BITMASK(40, 42); /* Disable HOL blocking */
+ xscom_write(p->chip_id, p->pci_xscom + 0xf, reg);
+
+ /* PCI Hardware Configuration 0 Register - all store queues free */
+ xscom_read(p->chip_id, p->pe_xscom + 0x18, ®);
+ reg &= ~PPC_BIT(14);
+ reg |= PPC_BIT(15);
+ xscom_write(p->chip_id, p->pe_xscom + 0x18, reg);
+
+ /*
+ * PCI Hardware Configuration 1 Register - enable read response
+ * arrival/address request ordering
+ */
+ xscom_read(p->chip_id, p->pe_xscom + 0x19, ®);
+ reg |= PPC_BITMASK(17,18);
+ xscom_write(p->chip_id, p->pe_xscom + 0x19, reg);
+
+ /* AIB TX Command Credit Register - set AIB credit values back to normal */
+ xscom_read(p->chip_id, p->pci_xscom + 0xd, ®);
+ reg |= PPC_BIT(42);
+ reg &= ~PPC_BITMASK(43, 47);
+ xscom_write(p->chip_id, p->pci_xscom + 0xd, reg);
+
+ /* AIB TX Credit Init Timer - reset timer */
+ xscom_write(p->chip_id, p->pci_xscom + 0xc, 0xff00000000000000ull);
+
+ /* PBCQ Mode Control Register - set dcache handling to normal, not CAPP mode */
+ xscom_read(p->chip_id, p->pe_xscom + 0xb, ®);
+ reg &= ~PPC_BIT(25);
+ xscom_write(p->chip_id, p->pe_xscom + 0xb, reg);
+
+ /* Registers touched by phb3_init_capp_regs() */
+
+ /* CAPP Transport Control Register */
+ xscom_write(p->chip_id, TRANSPORT_CONTROL + offset, 0x0001000000000000);
+
+ /* Canned pResp Map Register 0/1/2 */
+ xscom_write(p->chip_id, CANNED_PRESP_MAP0 + offset, 0);
+ xscom_write(p->chip_id, CANNED_PRESP_MAP1 + offset, 0);
+ xscom_write(p->chip_id, CANNED_PRESP_MAP2 + offset, 0);
+
+ /* Flush SUE State Map Register */
+ xscom_write(p->chip_id, FLUSH_SUE_STATE_MAP + offset, 0);
+
+ /* CAPP Epoch and Recovery Timers Control Register */
+ xscom_write(p->chip_id, CAPP_EPOCH_TIMER_CTRL + offset, 0);
+
+ /* PE Secure CAPP Enable Register - we're all done! Disable CAPP mode! */
+ xscom_write(p->chip_id, PE_CAPP_EN + PE_REG_OFFSET(p), 0x0000000000000000);
+
+ /* Trigger CAPP recovery scoms after reinit */
+ p->flags |= PHB3_CAPP_DISABLING;
+
+ chip->capp_phb3_attached_mask &= ~(1 << p->index);
+ unlock(&capi_lock);
+
+ return OPAL_SUCCESS;
+}
+
static int64_t phb3_set_capi_mode(struct phb *phb, uint64_t mode,
uint64_t pe_number)
{
diff --git a/include/phb3.h b/include/phb3.h
index cf4b910..3d8e1b2 100644
--- a/include/phb3.h
+++ b/include/phb3.h
@@ -259,10 +259,11 @@ struct phb3_err {
#define PHB3_LINK_ELECTRICAL_RETRIES 20
/* PHB3 flags */
-#define PHB3_AIB_FENCED 0x00000001
-#define PHB3_CFG_USE_ASB 0x00000002
-#define PHB3_CFG_BLOCKED 0x00000004
-#define PHB3_CAPP_RECOVERY 0x00000008
+#define PHB3_AIB_FENCED (1 << 0)
+#define PHB3_CFG_USE_ASB (1 << 1)
+#define PHB3_CFG_BLOCKED (1 << 2)
+#define PHB3_CAPP_RECOVERY (1 << 3)
+#define PHB3_CAPP_DISABLING (1 << 4)
struct phb3 {
unsigned int index; /* 0..2 index inside P8 */
--
git-series 0.8.10
More information about the Skiboot
mailing list