hw/fsi: Introduce IBM's cfam

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

The Common FRU Access Macro (CFAM), an address space containing
various "engines" that drive accesses on busses internal and external
to the POWER chip. Examples include the SBEFIFO and I2C masters. The
engines hang off of an internal Local Bus (LBUS) which is described
by the CFAM configuration block.

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: - moved object FSIScratchPad under FSICFAMState
       - moved FSIScratchPad code under cfam.c
       - introduced fsi_cfam_instance_init()
       - reworked fsi_cfam_realize() ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>

3 files changed, 174 insertions, 1 deletions

diff --git a/hw/fsi/cfam.c b/hw/fsi/cfam.c
new file mode 100644
index 0000000..c62f0f7
--- /dev/null
+++ b/hw/fsi/cfam.c
@@ -0,0 +1,168 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright (C) 2024 IBM Corp.
+ *
+ * IBM Common FRU Access Macro
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/units.h"
+
+#include "qapi/error.h"
+#include "trace.h"
+
+#include "hw/fsi/cfam.h"
+#include "hw/fsi/fsi.h"
+
+#include "hw/qdev-properties.h"
+
+#define ENGINE_CONFIG_NEXT            BIT(31)
+#define ENGINE_CONFIG_TYPE_PEEK       (0x02 << 4)
+#define ENGINE_CONFIG_TYPE_FSI        (0x03 << 4)
+#define ENGINE_CONFIG_TYPE_SCRATCHPAD (0x06 << 4)
+
+/* Valid, slots, version, type, crc */
+#define CFAM_CONFIG_REG(__VER, __TYPE, __CRC)   \
+    (ENGINE_CONFIG_NEXT       |   \
+     0x00010000               |   \
+     (__VER)                  |   \
+     (__TYPE)                 |   \
+     (__CRC))
+
+#define TO_REG(x)                          ((x) >> 2)
+
+#define CFAM_CONFIG_CHIP_ID                TO_REG(0x00)
+#define CFAM_CONFIG_PEEK_STATUS            TO_REG(0x04)
+#define CFAM_CONFIG_CHIP_ID_P9             0xc0022d15
+#define CFAM_CONFIG_CHIP_ID_BREAK          0xc0de0000
+
+static uint64_t fsi_cfam_config_read(void *opaque, hwaddr addr, unsigned size)
+{
+    trace_fsi_cfam_config_read(addr, size);
+
+    switch (addr) {
+    case 0x00:
+        return CFAM_CONFIG_CHIP_ID_P9;
+    case 0x04:
+        return CFAM_CONFIG_REG(0x1000, ENGINE_CONFIG_TYPE_PEEK, 0xc);
+    case 0x08:
+        return CFAM_CONFIG_REG(0x5000, ENGINE_CONFIG_TYPE_FSI, 0xa);
+    case 0xc:
+        return CFAM_CONFIG_REG(0x1000, ENGINE_CONFIG_TYPE_SCRATCHPAD, 0x7);
+    default:
+        /*
+         * The config table contains different engines from 0xc onwards.
+         * The scratch pad is already added at address 0xc. We need to add
+         * future engines from address 0x10 onwards. Returning 0 as engine
+         * is not implemented.
+         */
+        return 0;
+    }
+}
+
+static void fsi_cfam_config_write(void *opaque, hwaddr addr, uint64_t data,
+                                  unsigned size)
+{
+    FSICFAMState *cfam = FSI_CFAM(opaque);
+
+    trace_fsi_cfam_config_write(addr, size, data);
+
+    switch (TO_REG(addr)) {
+    case CFAM_CONFIG_CHIP_ID:
+    case CFAM_CONFIG_PEEK_STATUS:
+        if (data == CFAM_CONFIG_CHIP_ID_BREAK) {
+            bus_cold_reset(BUS(&cfam->lbus));
+        }
+        break;
+    default:
+        trace_fsi_cfam_config_write_noaddr(addr, size, data);
+    }
+}
+
+static const struct MemoryRegionOps cfam_config_ops = {
+    .read = fsi_cfam_config_read,
+    .write = fsi_cfam_config_write,
+    .valid.max_access_size = 4,
+    .valid.min_access_size = 4,
+    .impl.max_access_size = 4,
+    .impl.min_access_size = 4,
+    .endianness = DEVICE_BIG_ENDIAN,
+};
+
+static uint64_t fsi_cfam_unimplemented_read(void *opaque, hwaddr addr,
+                                            unsigned size)
+{
+    trace_fsi_cfam_unimplemented_read(addr, size);
+
+    return 0;
+}
+
+static void fsi_cfam_unimplemented_write(void *opaque, hwaddr addr,
+                                         uint64_t data, unsigned size)
+{
+    trace_fsi_cfam_unimplemented_write(addr, size, data);
+}
+
+static const struct MemoryRegionOps fsi_cfam_unimplemented_ops = {
+    .read = fsi_cfam_unimplemented_read,
+    .write = fsi_cfam_unimplemented_write,
+    .endianness = DEVICE_BIG_ENDIAN,
+};
+
+static void fsi_cfam_instance_init(Object *obj)
+{
+    FSICFAMState *s = FSI_CFAM(obj);
+
+    object_initialize_child(obj, "scratchpad", &s->scratchpad,
+                            TYPE_FSI_SCRATCHPAD);
+}
+
+static void fsi_cfam_realize(DeviceState *dev, Error **errp)
+{
+    FSICFAMState *cfam = FSI_CFAM(dev);
+    FSISlaveState *slave = FSI_SLAVE(dev);
+
+    /* Each slave has a 2MiB address space */
+    memory_region_init_io(&cfam->mr, OBJECT(cfam), &fsi_cfam_unimplemented_ops,
+                          cfam, TYPE_FSI_CFAM, 2 * MiB);
+
+    qbus_init(&cfam->lbus, sizeof(cfam->lbus), TYPE_FSI_LBUS, DEVICE(cfam),
+              NULL);
+
+    memory_region_init_io(&cfam->config_iomem, OBJECT(cfam), &cfam_config_ops,
+                          cfam, TYPE_FSI_CFAM ".config", 0x400);
+
+    memory_region_add_subregion(&cfam->mr, 0, &cfam->config_iomem);
+    memory_region_add_subregion(&cfam->mr, 0x800, &slave->iomem);
+    memory_region_add_subregion(&cfam->mr, 0xc00, &cfam->lbus.mr);
+
+    /* Add scratchpad engine */
+    if (!qdev_realize(DEVICE(&cfam->scratchpad), BUS(&cfam->lbus), errp)) {
+        return;
+    }
+
+    FSILBusDevice *fsi_dev = FSI_LBUS_DEVICE(&cfam->scratchpad);
+    memory_region_add_subregion(&cfam->lbus.mr, 0, &fsi_dev->iomem);
+}
+
+static void fsi_cfam_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    dc->bus_type = TYPE_FSI_BUS;
+    dc->realize = fsi_cfam_realize;
+}
+
+static const TypeInfo fsi_cfam_info = {
+    .name = TYPE_FSI_CFAM,
+    .parent = TYPE_FSI_SLAVE,
+    .instance_init = fsi_cfam_instance_init,
+    .instance_size = sizeof(FSICFAMState),
+    .class_init = fsi_cfam_class_init,
+};
+
+static void fsi_cfam_register_types(void)
+{
+    type_register_static(&fsi_cfam_info);
+}
+
+type_init(fsi_cfam_register_types);
diff --git a/hw/fsi/meson.build b/hw/fsi/meson.build
index 574f5f9..96403d4 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'))
+system_ss.add(when: 'CONFIG_FSI', if_true: files('lbus.c','fsi.c','cfam.c'))
diff --git a/hw/fsi/trace-events b/hw/fsi/trace-events
index 8f29adb..b542956 100644
--- a/hw/fsi/trace-events
+++ b/hw/fsi/trace-events
@@ -2,3 +2,8 @@ fsi_scratchpad_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
 fsi_scratchpad_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
 fsi_slave_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
 fsi_slave_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
+fsi_cfam_config_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
+fsi_cfam_config_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=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