[15/18] ppc/pnv: Add POWER10 ChipTOD quirk for big-core

Commit Message

Nicholas Piggin July 11, 2024, 2:18 p.m. UTC

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 <[e-mail]>
---
 include/hw/ppc/pnv.h         | 1 +
 include/hw/ppc/pnv_core.h    | 7 +++++++
 hw/ppc/pnv.c                 | 1 +
 hw/ppc/pnv_core.c            | 3 +++
 target/ppc/timebase_helper.c | 9 +++++++++
 5 files changed, 21 insertions(+)

Patch

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 d7488be74c..efc9cf2cc3 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -2650,6 +2650,7 @@  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/hw/ppc/pnv_core.c b/hw/ppc/pnv_core.c
index a96ec4e2b9..68cc5914c6 100644
--- a/hw/ppc/pnv_core.c
+++ b/hw/ppc/pnv_core.c
@@ -280,6 +280,7 @@  static void pnv_core_realize(DeviceState *dev, Error **errp)
     PnvCore *pc = PNV_CORE(OBJECT(dev));
     PnvCoreClass *pcc = PNV_CORE_GET_CLASS(pc);
     CPUCore *cc = CPU_CORE(OBJECT(dev));
+    PnvMachineClass *pmc = PNV_MACHINE_GET_CLASS(pc->chip->pnv_machine);
     const char *typename = pnv_core_cpu_typename(pc);
     Error *local_err = NULL;
     void *obj;
@@ -288,6 +289,8 @@  static void pnv_core_realize(DeviceState *dev, Error **errp)
 
     assert(pc->chip);
 
+    pc->tod_state.big_core_quirk = pmc->quirk_tb_big_core;
+
     pc->threads = g_new(PowerPCCPU *, cc->nr_threads);
     for (i = 0; i < cc->nr_threads; i++) {
         PowerPCCPU *cpu;
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;
 }