[PATCH v2 14/19] ppc/pnv: Add POWER10 ChipTOD quirk for big-core

[Nicholas Piggin]

POWER10 has a quirk in its ChipTOD addressing that requires the even
small-core to be selected even when programming the odd small-core.
This allows skiboot chiptod init to run in big-core mode.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 include/hw/ppc/pnv.h         | 1 +
 include/hw/ppc/pnv_core.h    | 7 +++++++
 hw/ppc/pnv.c                 | 7 ++++++-
 target/ppc/timebase_helper.c | 9 +++++++++
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/include/hw/ppc/pnv.h b/include/hw/ppc/pnv.h
index 283ddd50e7..c56d152889 100644
--- a/include/hw/ppc/pnv.h
+++ b/include/hw/ppc/pnv.h
@@ -77,6 +77,7 @@ struct PnvMachineClass {
     const char *compat;
     int compat_size;
     int max_smt_threads;
+    bool quirk_tb_big_core;
 
     void (*dt_power_mgt)(PnvMachineState *pnv, void *fdt);
     void (*i2c_init)(PnvMachineState *pnv);
diff --git a/include/hw/ppc/pnv_core.h b/include/hw/ppc/pnv_core.h
index 50164e9e1f..c8784777a4 100644
--- a/include/hw/ppc/pnv_core.h
+++ b/include/hw/ppc/pnv_core.h
@@ -27,6 +27,13 @@
 
 /* Per-core ChipTOD / TimeBase state */
 typedef struct PnvCoreTODState {
+    /*
+     * POWER10 DD2.0 - big core TFMR drives the state machine on the even
+     * small core. Skiboot has a workaround that targets the even small core
+     * for CHIPTOD_TO_TB ops.
+     */
+    bool big_core_quirk;
+
     int tb_ready_for_tod; /* core TB ready to receive TOD from chiptod */
     int tod_sent_to_tb;   /* chiptod sent TOD to the core TB */
 
diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index fdf66323b8..24f7c007ce 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -2288,11 +2288,12 @@ static void pnv_chip_core_sanitize(PnvMachineState 
*pnv, PnvChip *chip,
 
 static void pnv_chip_core_realize(PnvChip *chip, Error **errp)
 {
+    PnvMachineState *pnv = PNV_MACHINE(qdev_get_machine());
+    PnvMachineClass *pmc = PNV_MACHINE_GET_CLASS(pnv);
     Error *error = NULL;
     PnvChipClass *pcc = PNV_CHIP_GET_CLASS(chip);
     const char *typename = pnv_chip_core_typename(chip);
     int i, core_hwid;
-    PnvMachineState *pnv = PNV_MACHINE(qdev_get_machine());
 
     if (!object_class_by_name(typename)) {
         error_setg(errp, "Unable to find PowerNV CPU Core '%s'", typename);
@@ -2335,6 +2336,9 @@ static void pnv_chip_core_realize(PnvChip *chip, Error 
**errp)
                                 &error_fatal);
         object_property_set_link(OBJECT(pnv_core), "chip", OBJECT(chip),
                                  &error_abort);
+
+        pnv_core->tod_state.big_core_quirk = pmc->quirk_tb_big_core;
+
         qdev_realize(DEVICE(pnv_core), NULL, &error_fatal);
 
         /* Each core has an XSCOM MMIO region */
@@ -2647,6 +2651,7 @@ static void pnv_machine_p10_common_class_init(ObjectClass 
*oc, void *data)
     pmc->compat = compat;
     pmc->compat_size = sizeof(compat);
     pmc->max_smt_threads = 4;
+    pmc->quirk_tb_big_core = true;
     pmc->dt_power_mgt = pnv_dt_power_mgt;
 
     xfc->match_nvt = pnv10_xive_match_nvt;
diff --git a/target/ppc/timebase_helper.c b/target/ppc/timebase_helper.c
index 44cacf065e..019b8ee41f 100644
--- a/target/ppc/timebase_helper.c
+++ b/target/ppc/timebase_helper.c
@@ -20,6 +20,7 @@
 #include "cpu.h"
 #include "hw/ppc/ppc.h"
 #include "hw/ppc/pnv_core.h"
+#include "hw/ppc/pnv_chip.h"
 #include "exec/helper-proto.h"
 #include "exec/exec-all.h"
 #include "qemu/log.h"
@@ -297,6 +298,14 @@ static PnvCoreTODState *cpu_get_tbst(PowerPCCPU *cpu)
 {
     PnvCore *pc = pnv_cpu_state(cpu)->pnv_core;
 
+    if (pc->big_core && pc->tod_state.big_core_quirk) {
+        /* Must operate on the even small core */
+        int core_id = CPU_CORE(pc)->core_id;
+        if (core_id & 1) {
+            pc = pc->chip->cores[core_id & ~1];
+        }
+    }
+
     return &pc->tod_state;
 }
 
-- 
2.45.1