One of the functions of the ChipTOD is to transfer TOD to the Core
(aka PC - Pervasive Core) timebase facility.
The ChipTOD can be programmed with a target address to send the TOD
value to. The hardware implementation seems to perform this by
sending the TOD value to a SCOM address.
This implementation grabs the core directly and manipulates the
timebase facility state in the core. This is a hack, but it works
enough for now. A better implementation would implement the transfer
to the PnvCore xscom register and drive the timebase state machine
from there.
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
hw/ppc/pnv.c | 15 ++++
hw/ppc/pnv_chiptod.c | 132 +++++++++++++++++++++++++++++++++++
include/hw/ppc/pnv.h | 2 +
include/hw/ppc/pnv_chiptod.h | 4 ++
target/ppc/cpu.h | 13 ++++
5 files changed, 166 insertions(+)
diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index 8beddb1313..0b47b92baa 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -2121,6 +2121,21 @@ static void pnv_chip_class_init(ObjectClass *klass, void *data)
dc->desc = "PowerNV Chip";
}
+PnvCore *pnv_chip_find_core(PnvChip *chip, uint32_t core_id)
+{
+ int i;
+
+ for (i = 0; i < chip->nr_cores; i++) {
+ PnvCore *pc = chip->cores[i];
+ CPUCore *cc = CPU_CORE(pc);
+
+ if (cc->core_id == core_id) {
+ return pc;
+ }
+ }
+ return NULL;
+}
+
PowerPCCPU *pnv_chip_find_cpu(PnvChip *chip, uint32_t pir)
{
int i, j;
diff --git a/hw/ppc/pnv_chiptod.c b/hw/ppc/pnv_chiptod.c
index 6ac3eac9d0..3831a72101 100644
--- a/hw/ppc/pnv_chiptod.c
+++ b/hw/ppc/pnv_chiptod.c
@@ -210,6 +210,79 @@ static void chiptod_power10_broadcast_ttype(PnvChipTOD *sender,
}
}
+static PnvCore *pnv_chip_get_core_by_xscom_base(PnvChip *chip,
+ uint32_t xscom_base)
+{
+ PnvChipClass *pcc = PNV_CHIP_GET_CLASS(chip);
+ int i;
+
+ for (i = 0; i < chip->nr_cores; i++) {
+ PnvCore *pc = chip->cores[i];
+ CPUCore *cc = CPU_CORE(pc);
+ int core_hwid = cc->core_id;
+
+ if (pcc->xscom_core_base(chip, core_hwid) == xscom_base) {
+ return pc;
+ }
+ }
+ return NULL;
+}
+
+static PnvCore *chiptod_power9_tx_ttype_target(PnvChipTOD *chiptod,
+ uint64_t val)
+{
+ /*
+ * skiboot uses Core ID for P9, though SCOM should work too.
+ */
+ if (val & PPC_BIT(35)) { /* SCOM addressing */
+ uint32_t addr = val >> 32;
+ uint32_t reg = addr & 0xfff;
+
+ if (reg != PC_TOD) {
+ qemu_log_mask(LOG_GUEST_ERROR, "pnv_chiptod: SCOM addressing: "
+ "unimplemented slave register 0x%" PRIx32 "\n", reg);
+ return NULL;
+ }
+
+ return pnv_chip_get_core_by_xscom_base(chiptod->chip, addr & ~0xfff);
+
+ } else { /* Core ID addressing */
+ uint32_t core_id = GETFIELD(TOD_TX_TTYPE_PIB_SLAVE_ADDR, val) & 0x1f;
+ return pnv_chip_find_core(chiptod->chip, core_id);
+ }
+}
+
+static PnvCore *chiptod_power10_tx_ttype_target(PnvChipTOD *chiptod,
+ uint64_t val)
+{
+ /*
+ * skiboot uses SCOM for P10 because Core ID was unable to be made to
+ * work correctly. For this reason only SCOM addressing is implemented.
+ */
+ if (val & PPC_BIT(35)) { /* SCOM addressing */
+ uint32_t addr = val >> 32;
+ uint32_t reg = addr & 0xfff;
+
+ if (reg != PC_TOD) {
+ qemu_log_mask(LOG_GUEST_ERROR, "pnv_chiptod: SCOM addressing: "
+ "unimplemented slave register 0x%" PRIx32 "\n", reg);
+ return NULL;
+ }
+
+ /*
+ * This may not deal with P10 big-core addressing at the moment.
+ * The big-core code in skiboot syncs small cores, but it targets
+ * the even PIR (first small-core) when syncing second small-core.
+ */
+ return pnv_chip_get_core_by_xscom_base(chiptod->chip, addr & ~0xfff);
+
+ } else { /* Core ID addressing */
+ qemu_log_mask(LOG_UNIMP, "pnv_chiptod: TX TTYPE Core ID "
+ "addressing is not implemented for POWER10\n");
+ return NULL;
+ }
+}
+
static void pnv_chiptod_xscom_write(void *opaque, hwaddr addr,
uint64_t val, unsigned size)
{
@@ -231,6 +304,22 @@ static void pnv_chiptod_xscom_write(void *opaque, hwaddr addr,
chiptod->pss_mss_ctrl_reg = val & PPC_BITMASK(0, 31);
break;
+ case TOD_TX_TTYPE_CTRL_REG:
+ /*
+ * This register sets the target of the TOD value transfer initiated
+ * by TOD_MOVE_TOD_TO_TB. The TOD is able to send the address to
+ * any target register, though in practice only the PC TOD register
+ * should be used. ChipTOD has a "SCOM addressing" mode which fully
+ * specifies the SCOM address, and a core-ID mode which uses the
+ * core ID to target the PC TOD for a given core.
+ */
+ chiptod->slave_pc_target = pctc->tx_ttype_target(chiptod, val);
+ if (!chiptod->slave_pc_target) {
+ qemu_log_mask(LOG_GUEST_ERROR, "pnv_chiptod: xscom write reg"
+ " TOD_TX_TTYPE_CTRL_REG val 0x%" PRIx64
+ " invalid slave address\n", val);
+ }
+ break;
case TOD_ERROR_REG:
chiptod->tod_error &= ~val;
break;
@@ -256,6 +345,47 @@ static void pnv_chiptod_xscom_write(void *opaque, hwaddr addr,
}
}
break;
+
+ case TOD_MOVE_TOD_TO_TB_REG:
+ /*
+ * XXX: it should be a cleaner model to have this drive a SCOM
+ * transaction to the target address, and implement the state machine
+ * in the PnvCore. For now, this hack makes things work.
+ */
+ if (chiptod->tod_state != tod_running) {
+ qemu_log_mask(LOG_GUEST_ERROR, "pnv_chiptod: xscom write reg"
+ " TOD_MOVE_TOD_TO_TB_REG in bad state %d\n",
+ chiptod->tod_state);
+ } else if (!(val & PPC_BIT(0))) {
+ qemu_log_mask(LOG_GUEST_ERROR, "pnv_chiptod: xscom write reg"
+ " TOD_MOVE_TOD_TO_TB_REG with bad val 0x%" PRIx64"\n",
+ val);
+ } else if (chiptod->slave_pc_target == NULL) {
+ qemu_log_mask(LOG_GUEST_ERROR, "pnv_chiptod: xscom write reg"
+ " TOD_MOVE_TOD_TO_TB_REG with no slave target\n");
+ } else {
+ PowerPCCPU *cpu = chiptod->slave_pc_target->threads[0];
+ CPUPPCState *env = &cpu->env;
+
+ /*
+ * Moving TOD to TB will set the TB of all threads in a
+ * core, so skiboot only does this once per thread0, so
+ * that is where we keep the timebase state machine.
+ *
+ * It is likely possible for TBST to be driven from other
+ * threads in the core, but for now we only implement it for
+ * thread 0.
+ */
+
+ if (env->pnv_tod_tbst.tb_ready_for_tod) {
+ env->pnv_tod_tbst.tod_sent_to_tb = 1;
+ } else {
+ qemu_log_mask(LOG_GUEST_ERROR, "pnv_chiptod: xscom write reg"
+ " TOD_MOVE_TOD_TO_TB_REG with TB not ready to"
+ " receive TOD\n");
+ }
+ }
+ break;
case TOD_START_TOD_REG:
if (chiptod->tod_state != tod_stopped) {
qemu_log_mask(LOG_GUEST_ERROR, "pnv_chiptod: LOAD_TOG_REG in "
@@ -340,6 +470,7 @@ static void pnv_chiptod_power9_class_init(ObjectClass *klass, void *data)
xdc->dt_xscom = pnv_chiptod_power9_dt_xscom;
pctc->broadcast_ttype = chiptod_power9_broadcast_ttype;
+ pctc->tx_ttype_target = chiptod_power9_tx_ttype_target;
pctc->xscom_size = PNV_XSCOM_CHIPTOD_SIZE;
}
@@ -375,6 +506,7 @@ static void pnv_chiptod_power10_class_init(ObjectClass *klass, void *data)
xdc->dt_xscom = pnv_chiptod_power10_dt_xscom;
pctc->broadcast_ttype = chiptod_power10_broadcast_ttype;
+ pctc->tx_ttype_target = chiptod_power10_tx_ttype_target;
pctc->xscom_size = PNV_XSCOM_CHIPTOD_SIZE;
}
diff --git a/include/hw/ppc/pnv.h b/include/hw/ppc/pnv.h
index 110ac9aace..476b136146 100644
--- a/include/hw/ppc/pnv.h
+++ b/include/hw/ppc/pnv.h
@@ -28,6 +28,7 @@
#define TYPE_PNV_CHIP "pnv-chip"
+typedef struct PnvCore PnvCore;
typedef struct PnvChip PnvChip;
typedef struct Pnv8Chip Pnv8Chip;
typedef struct Pnv9Chip Pnv9Chip;
@@ -56,6 +57,7 @@ DECLARE_INSTANCE_CHECKER(PnvChip, PNV_CHIP_POWER9,
DECLARE_INSTANCE_CHECKER(PnvChip, PNV_CHIP_POWER10,
TYPE_PNV_CHIP_POWER10)
+PnvCore *pnv_chip_find_core(PnvChip *chip, uint32_t core_id);
PowerPCCPU *pnv_chip_find_cpu(PnvChip *chip, uint32_t pir);
typedef struct PnvPHB PnvPHB;
diff --git a/include/hw/ppc/pnv_chiptod.h b/include/hw/ppc/pnv_chiptod.h
index ca770525d9..fde569bcbf 100644
--- a/include/hw/ppc/pnv_chiptod.h
+++ b/include/hw/ppc/pnv_chiptod.h
@@ -25,6 +25,8 @@ enum tod_state {
tod_stopped = 1,
};
+typedef struct PnvCore PnvCore;
+
struct PnvChipTOD {
DeviceState xd;
@@ -36,12 +38,14 @@ struct PnvChipTOD {
enum tod_state tod_state;
uint64_t tod_error;
uint64_t pss_mss_ctrl_reg;
+ PnvCore *slave_pc_target;
};
struct PnvChipTODClass {
DeviceClass parent_class;
void (*broadcast_ttype)(PnvChipTOD *sender, uint32_t trigger);
+ PnvCore *(*tx_ttype_target)(PnvChipTOD *chiptod, uint64_t val);
int xscom_size;
};
diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index 16baea609c..0e932838aa 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -1183,6 +1183,13 @@ DEXCR_ASPECT(SRAPD, 4)
DEXCR_ASPECT(NPHIE, 5)
DEXCR_ASPECT(PHIE, 6)
+/*****************************************************************************/
+/* PowerNV ChipTOD and TimeBase State Machine */
+struct pnv_tod_tbst {
+ 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 */
+};
+
/*****************************************************************************/
/* The whole PowerPC CPU context */
@@ -1258,6 +1265,12 @@ struct CPUArchState {
uint32_t tlb_need_flush; /* Delayed flush needed */
#define TLB_NEED_LOCAL_FLUSH 0x1
#define TLB_NEED_GLOBAL_FLUSH 0x2
+
+#if defined(TARGET_PPC64)
+ /* PowerNV chiptod / timebase facility state. */
+ /* Would be nice to put these into PnvCore */
+ struct pnv_tod_tbst pnv_tod_tbst;
+#endif
#endif
/* Other registers */
--
2.42.0