ppc/pnv: Add OCC model stub with interrupt support

The OCC is an on-chip microcontroller based on a ppc405 core used
for various power management tasks. It comes with a pile of additional
hardware sitting on the PIB (aka XSCOM bus). At this point we don't
emulate it (nor plan to do so). However there is one facility which
is provided by the surrounding hardware that we do need, which is the
interrupt generation facility. OPAL uses it to send itself interrupts
under some circumstances and there are other uses around the corner.

So this implement just enough to support this.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[clg: - updated for qemu-2.9
      - changed the XSCOM interface to fit new model
      - QOMified the model ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

3 files changed, 150 insertions, 1 deletions

diff --git a/hw/ppc/Makefile.objs b/hw/ppc/Makefile.objs
index dc19ee17fa..ef67ea8201 100644
--- a/hw/ppc/Makefile.objs
+++ b/hw/ppc/Makefile.objs
@@ -6,7 +6,7 @@ obj-$(CONFIG_PSERIES) += spapr_hcall.o spapr_iommu.o spapr_rtas.o
 obj-$(CONFIG_PSERIES) += spapr_pci.o spapr_rtc.o spapr_drc.o spapr_rng.o
 obj-$(CONFIG_PSERIES) += spapr_cpu_core.o spapr_ovec.o
 # IBM PowerNV
-obj-$(CONFIG_POWERNV) += pnv.o pnv_xscom.o pnv_core.o pnv_lpc.o pnv_psi.o
+obj-$(CONFIG_POWERNV) += pnv.o pnv_xscom.o pnv_core.o pnv_lpc.o pnv_psi.o pnv_occ.o
 ifeq ($(CONFIG_PCI)$(CONFIG_PSERIES)$(CONFIG_LINUX), yyy)
 obj-y += spapr_pci_vfio.o
 endif
diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index a516acbe19..16f32c9bbd 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -694,6 +694,11 @@ static void pnv_chip_init(Object *obj)
     object_property_add_child(obj, "psi", OBJECT(&chip->psi), NULL);
     object_property_add_const_link(OBJECT(&chip->psi), "xics",
                                    OBJECT(qdev_get_machine()), &error_abort);
+
+    object_initialize(&chip->occ, sizeof(chip->occ), TYPE_PNV_OCC);
+    object_property_add_child(obj, "occ", OBJECT(&chip->occ), NULL);
+    object_property_add_const_link(OBJECT(&chip->occ), "psi",
+                                   OBJECT(&chip->psi), &error_abort);
 }
 
 static void pnv_chip_icp_realize(PnvChip *chip, Error **errp)
@@ -816,6 +821,14 @@ static void pnv_chip_realize(DeviceState *dev, Error **errp)
         return;
     }
     pnv_xscom_add_subregion(chip, PNV_XSCOM_PSIHB_BASE, &chip->psi.xscom_regs);
+
+    /* Create the simplified OCC model */
+    object_property_set_bool(OBJECT(&chip->occ), true, "realized", &error);
+    if (error) {
+        error_propagate(errp, error);
+        return;
+    }
+    pnv_xscom_add_subregion(chip, PNV_XSCOM_OCC_BASE, &chip->occ.xscom_regs);
 }
 
 static Property pnv_chip_properties[] = {
diff --git a/hw/ppc/pnv_occ.c b/hw/ppc/pnv_occ.c
new file mode 100644
index 0000000000..04880f26d6
--- /dev/null
+++ b/hw/ppc/pnv_occ.c
@@ -0,0 +1,136 @@
+/*
+ * QEMU PowerPC PowerNV Emulation of a few OCC related registers
+ *
+ * Copyright (c) 2015-2017, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/hw.h"
+#include "sysemu/sysemu.h"
+#include "target/ppc/cpu.h"
+#include "qapi/error.h"
+#include "qemu/log.h"
+
+#include "hw/ppc/pnv.h"
+#include "hw/ppc/pnv_xscom.h"
+#include "hw/ppc/pnv_occ.h"
+
+#define OCB_OCI_OCCMISC         0x4020
+#define OCB_OCI_OCCMISC_AND     0x4021
+#define OCB_OCI_OCCMISC_OR      0x4022
+
+static void pnv_occ_set_misc(PnvOCC *occ, uint64_t val)
+{
+    bool irq_state;
+
+    val &= 0xffff000000000000ull;
+
+    occ->occmisc = val;
+    irq_state = !!(val >> 63);
+    pnv_psi_irq_set(occ->psi, PSIHB_IRQ_OCC, irq_state);
+}
+
+static uint64_t pnv_occ_xscom_read(void *opaque, hwaddr addr, unsigned size)
+{
+    PnvOCC *occ = PNV_OCC(opaque);
+    uint32_t offset = addr >> 3;
+    uint64_t val = 0;
+
+    switch (offset) {
+    case OCB_OCI_OCCMISC:
+        val = occ->occmisc;
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "OCC Unimplemented register: Ox%"
+                      HWADDR_PRIx "\n", addr);
+    }
+    return val;
+}
+
+static void pnv_occ_xscom_write(void *opaque, hwaddr addr,
+                                uint64_t val, unsigned size)
+{
+    PnvOCC *occ = PNV_OCC(opaque);
+    uint32_t offset = addr >> 3;
+
+    switch (offset) {
+    case OCB_OCI_OCCMISC_AND:
+        pnv_occ_set_misc(occ, occ->occmisc & val);
+        break;
+    case OCB_OCI_OCCMISC_OR:
+        pnv_occ_set_misc(occ, occ->occmisc | val);
+        break;
+    case OCB_OCI_OCCMISC:
+        pnv_occ_set_misc(occ, val);
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "OCC Unimplemented register: Ox%"
+                      HWADDR_PRIx "\n", addr);
+    }
+}
+
+static const MemoryRegionOps pnv_occ_xscom_ops = {
+    .read = pnv_occ_xscom_read,
+    .write = pnv_occ_xscom_write,
+    .valid.min_access_size = 8,
+    .valid.max_access_size = 8,
+    .impl.min_access_size = 8,
+    .impl.max_access_size = 8,
+    .endianness = DEVICE_BIG_ENDIAN,
+};
+
+
+static void pnv_occ_realize(DeviceState *dev, Error **errp)
+{
+    PnvOCC *occ = PNV_OCC(dev);
+    Object *obj;
+    Error *error = NULL;
+
+    occ->occmisc = 0;
+
+    /* get PSI object from chip */
+    obj = object_property_get_link(OBJECT(dev), "psi", &error);
+    if (!obj) {
+        error_setg(errp, "%s: required link 'psi' not found: %s",
+                   __func__, error_get_pretty(error));
+        return;
+    }
+    occ->psi = PNV_PSI(obj);
+
+    /* XScom region for OCC registers */
+    pnv_xscom_region_init(&occ->xscom_regs, OBJECT(dev), &pnv_occ_xscom_ops,
+                  occ, "xscom-occ", PNV_XSCOM_OCC_SIZE);
+}
+
+static void pnv_occ_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = pnv_occ_realize;
+}
+
+static const TypeInfo pnv_occ_type_info = {
+    .name          = TYPE_PNV_OCC,
+    .parent        = TYPE_DEVICE,
+    .instance_size = sizeof(PnvOCC),
+    .class_init    = pnv_occ_class_init,
+};
+
+static void pnv_occ_register_types(void)
+{
+    type_register_static(&pnv_occ_type_info);
+}
+
+type_init(pnv_occ_register_types)