hw/fsi: Introduce IBM's FSI master

This is a part of patchset where IBM's Flexible Service Interface is
introduced.

This commit models the FSI master. CFAM is hanging out of FSI master which is a bus controller.

The FSI master: A controller in the platform service processor (e.g.
BMC) driving CFAM engine accesses into the POWER chip. At the
hardware level FSI is a bit-based protocol supporting synchronous and
DMA-driven accesses of engines in a CFAM.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[ clg: - move FSICFAMState object under FSIMasterState
       - introduced fsi_master_init()
       - reworked fsi_master_realize()
       - dropped FSIBus definition ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>

3 files changed, 173 insertions, 1 deletions

diff --git a/hw/fsi/fsi-master.c b/hw/fsi/fsi-master.c
new file mode 100644
index 0000000000..a5f0598c98
--- /dev/null
+++ b/hw/fsi/fsi-master.c
@@ -0,0 +1,170 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright (C) 2024 IBM Corp.
+ *
+ * IBM Flexible Service Interface master
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/log.h"
+#include "trace.h"
+
+#include "hw/fsi/fsi-master.h"
+
+#define TYPE_OP_BUS "opb"
+
+#define TO_REG(x)                               ((x) >> 2)
+
+#define FSI_MENP0                               TO_REG(0x010)
+#define FSI_MENP32                              TO_REG(0x014)
+#define FSI_MSENP0                              TO_REG(0x018)
+#define FSI_MLEVP0                              TO_REG(0x018)
+#define FSI_MSENP32                             TO_REG(0x01c)
+#define FSI_MLEVP32                             TO_REG(0x01c)
+#define FSI_MCENP0                              TO_REG(0x020)
+#define FSI_MREFP0                              TO_REG(0x020)
+#define FSI_MCENP32                             TO_REG(0x024)
+#define FSI_MREFP32                             TO_REG(0x024)
+
+#define FSI_MVER                                TO_REG(0x074)
+#define FSI_MRESP0                              TO_REG(0x0d0)
+
+#define FSI_MRESB0                              TO_REG(0x1d0)
+#define   FSI_MRESB0_RESET_GENERAL              BIT(31)
+#define   FSI_MRESB0_RESET_ERROR                BIT(30)
+
+static uint64_t fsi_master_read(void *opaque, hwaddr addr, unsigned size)
+{
+    FSIMasterState *s = FSI_MASTER(opaque);
+    int reg = TO_REG(addr);
+
+    trace_fsi_master_read(addr, size);
+
+    if (reg >= FSI_MASTER_NR_REGS) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Out of bounds read: 0x%"HWADDR_PRIx" for %u\n",
+                      __func__, addr, size);
+        return 0;
+    }
+
+    return s->regs[reg];
+}
+
+static void fsi_master_write(void *opaque, hwaddr addr, uint64_t data,
+                             unsigned size)
+{
+    FSIMasterState *s = FSI_MASTER(opaque);
+    int reg = TO_REG(addr);
+
+    trace_fsi_master_write(addr, size, data);
+
+    if (reg >= FSI_MASTER_NR_REGS) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Out of bounds write: %"HWADDR_PRIx" for %u\n",
+                      __func__, addr, size);
+        return;
+    }
+
+    switch (reg) {
+    case FSI_MENP0:
+        s->regs[FSI_MENP0] = data;
+        break;
+    case FSI_MENP32:
+        s->regs[FSI_MENP32] = data;
+        break;
+    case FSI_MSENP0:
+        s->regs[FSI_MENP0] |= data;
+        break;
+    case FSI_MSENP32:
+        s->regs[FSI_MENP32] |= data;
+        break;
+    case FSI_MCENP0:
+        s->regs[FSI_MENP0] &= ~data;
+        break;
+    case FSI_MCENP32:
+        s->regs[FSI_MENP32] &= ~data;
+        break;
+    case FSI_MRESP0:
+        /* Perform necessary resets leave register 0 to indicate no errors */
+        break;
+    case FSI_MRESB0:
+        if (data & FSI_MRESB0_RESET_GENERAL) {
+            device_cold_reset(DEVICE(opaque));
+        }
+        if (data & FSI_MRESB0_RESET_ERROR) {
+            /* FIXME: this seems dubious */
+            device_cold_reset(DEVICE(opaque));
+        }
+        break;
+    default:
+        s->regs[reg] = data;
+    }
+}
+
+static const struct MemoryRegionOps fsi_master_ops = {
+    .read = fsi_master_read,
+    .write = fsi_master_write,
+    .endianness = DEVICE_BIG_ENDIAN,
+};
+
+static void fsi_master_init(Object *o)
+{
+    FSIMasterState *s = FSI_MASTER(o);
+
+    object_initialize_child(o, "cfam", &s->cfam, TYPE_FSI_CFAM);
+
+    qbus_init(&s->bus, sizeof(s->bus), TYPE_FSI_BUS, DEVICE(s), NULL);
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &fsi_master_ops, s,
+                          TYPE_FSI_MASTER, 0x10000000);
+    memory_region_init(&s->opb2fsi, OBJECT(s), "fsi.opb2fsi", 0x10000000);
+}
+
+static void fsi_master_realize(DeviceState *dev, Error **errp)
+{
+    FSIMasterState *s = FSI_MASTER(dev);
+
+    if (!qdev_realize(DEVICE(&s->cfam), BUS(&s->bus), errp)) {
+        return;
+    }
+
+    /* address ? */
+    memory_region_add_subregion(&s->opb2fsi, 0, &s->cfam.mr);
+}
+
+static void fsi_master_reset(DeviceState *dev)
+{
+    FSIMasterState *s = FSI_MASTER(dev);
+
+    /* Initialize registers */
+    memset(s->regs, 0, sizeof(s->regs));
+
+    /* ASPEED default */
+    s->regs[FSI_MVER] = 0xe0050101;
+}
+
+static void fsi_master_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->bus_type = TYPE_OP_BUS;
+    dc->desc = "FSI Master";
+    dc->realize = fsi_master_realize;
+    dc->reset = fsi_master_reset;
+}
+
+static const TypeInfo fsi_master_info = {
+    .name = TYPE_FSI_MASTER,
+    .parent = TYPE_DEVICE,
+    .instance_init = fsi_master_init,
+    .instance_size = sizeof(FSIMasterState),
+    .class_init = fsi_master_class_init,
+};
+
+static void fsi_register_types(void)
+{
+    type_register_static(&fsi_master_info);
+}
+
+type_init(fsi_register_types);
diff --git a/hw/fsi/meson.build b/hw/fsi/meson.build
index 96403d4efc..7803b3afd1 100644
--- a/hw/fsi/meson.build
+++ b/hw/fsi/meson.build
@@ -1 +1 @@
-system_ss.add(when: 'CONFIG_FSI', if_true: files('lbus.c','fsi.c','cfam.c'))
+system_ss.add(when: 'CONFIG_FSI', if_true: files('lbus.c','fsi.c','cfam.c','fsi-master.c'))
diff --git a/hw/fsi/trace-events b/hw/fsi/trace-events
index b542956fb3..bf417b6dc3 100644
--- a/hw/fsi/trace-events
+++ b/hw/fsi/trace-events
@@ -7,3 +7,5 @@ fsi_cfam_config_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64
 fsi_cfam_unimplemented_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
 fsi_cfam_unimplemented_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
 fsi_cfam_config_write_noaddr(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
+fsi_master_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
+fsi_master_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64