hw/arm/sysbus-fdt: helpers for platform bus nodes addition

This new C module will be used by ARM machine files to generate
platform bus node and their dynamic sysbus device tree nodes.

Dynamic sysbus device node addition is done in a machine init
done notifier. arm_register_platform_bus_fdt_creator does the
registration of this latter and is supposed to be called by
ARM machine files that support platform bus and their dynamic
sysbus. Addition of dynamic sysbus nodes is done only if the
user did not provide any dtb.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Shannon Zhao <zhaoshenglong@huawei.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1433244554-12898-2-git-send-email-eric.auger@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 174 insertions, 0 deletions

diff --git a/hw/arm/sysbus-fdt.c b/hw/arm/sysbus-fdt.c
new file mode 100644
index 0000000..3038b94
--- /dev/null
+++ b/hw/arm/sysbus-fdt.c
@@ -0,0 +1,174 @@
+/*
+ * ARM Platform Bus device tree generation helpers
+ *
+ * Copyright (c) 2014 Linaro Limited
+ *
+ * Authors:
+ *  Alex Graf <agraf@suse.de>
+ *  Eric Auger <eric.auger@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 "hw/arm/sysbus-fdt.h"
+#include "qemu/error-report.h"
+#include "sysemu/device_tree.h"
+#include "hw/platform-bus.h"
+#include "sysemu/sysemu.h"
+
+/*
+ * internal struct that contains the information to create dynamic
+ * sysbus device node
+ */
+typedef struct PlatformBusFDTData {
+    void *fdt; /* device tree handle */
+    int irq_start; /* index of the first IRQ usable by platform bus devices */
+    const char *pbus_node_name; /* name of the platform bus node */
+    PlatformBusDevice *pbus;
+} PlatformBusFDTData;
+
+/*
+ * struct used when calling the machine init done notifier
+ * that constructs the fdt nodes of platform bus devices
+ */
+typedef struct PlatformBusFDTNotifierParams {
+    Notifier notifier;
+    ARMPlatformBusFDTParams *fdt_params;
+} PlatformBusFDTNotifierParams;
+
+/* struct that associates a device type name and a node creation function */
+typedef struct NodeCreationPair {
+    const char *typename;
+    int (*add_fdt_node_fn)(SysBusDevice *sbdev, void *opaque);
+} NodeCreationPair;
+
+/* list of supported dynamic sysbus devices */
+static const NodeCreationPair add_fdt_node_functions[] = {
+    {"", NULL}, /* last element */
+};
+
+/**
+ * add_fdt_node - add the device tree node of a dynamic sysbus device
+ *
+ * @sbdev: handle to the sysbus device
+ * @opaque: handle to the PlatformBusFDTData
+ *
+ * Checks the sysbus type belongs to the list of device types that
+ * are dynamically instantiable and if so call the node creation
+ * function.
+ */
+static int add_fdt_node(SysBusDevice *sbdev, void *opaque)
+{
+    int i, ret;
+
+    for (i = 0; i < ARRAY_SIZE(add_fdt_node_functions); i++) {
+        if (!strcmp(object_get_typename(OBJECT(sbdev)),
+                    add_fdt_node_functions[i].typename)) {
+            ret = add_fdt_node_functions[i].add_fdt_node_fn(sbdev, opaque);
+            assert(!ret);
+            return 0;
+        }
+    }
+    error_report("Device %s can not be dynamically instantiated",
+                     qdev_fw_name(DEVICE(sbdev)));
+    exit(1);
+}
+
+/**
+ * add_all_platform_bus_fdt_nodes - create all the platform bus nodes
+ *
+ * builds the parent platform bus node and all the nodes of dynamic
+ * sysbus devices attached to it.
+ */
+static void add_all_platform_bus_fdt_nodes(ARMPlatformBusFDTParams *fdt_params)
+{
+    const char platcomp[] = "qemu,platform\0simple-bus";
+    PlatformBusDevice *pbus;
+    DeviceState *dev;
+    gchar *node;
+    uint64_t addr, size;
+    int irq_start, dtb_size;
+    struct arm_boot_info *info = fdt_params->binfo;
+    const ARMPlatformBusSystemParams *params = fdt_params->system_params;
+    const char *intc = fdt_params->intc;
+    void *fdt = info->get_dtb(info, &dtb_size);
+
+    /*
+     * If the user provided a dtb, we assume the dynamic sysbus nodes
+     * already are integrated there. This corresponds to a use case where
+     * the dynamic sysbus nodes are complex and their generation is not yet
+     * supported. In that case the user can take charge of the guest dt
+     * while qemu takes charge of the qom stuff.
+     */
+    if (info->dtb_filename) {
+        return;
+    }
+
+    assert(fdt);
+
+    node = g_strdup_printf("/platform@%"PRIx64, params->platform_bus_base);
+    addr = params->platform_bus_base;
+    size = params->platform_bus_size;
+    irq_start = params->platform_bus_first_irq;
+
+    /* Create a /platform node that we can put all devices into */
+    qemu_fdt_add_subnode(fdt, node);
+    qemu_fdt_setprop(fdt, node, "compatible", platcomp, sizeof(platcomp));
+
+    /* Our platform bus region is less than 32bits, so 1 cell is enough for
+     * address and size
+     */
+    qemu_fdt_setprop_cells(fdt, node, "#size-cells", 1);
+    qemu_fdt_setprop_cells(fdt, node, "#address-cells", 1);
+    qemu_fdt_setprop_cells(fdt, node, "ranges", 0, addr >> 32, addr, size);
+
+    qemu_fdt_setprop_phandle(fdt, node, "interrupt-parent", intc);
+
+    dev = qdev_find_recursive(sysbus_get_default(), TYPE_PLATFORM_BUS_DEVICE);
+    pbus = PLATFORM_BUS_DEVICE(dev);
+
+    /* We can only create dt nodes for dynamic devices when they're ready */
+    assert(pbus->done_gathering);
+
+    PlatformBusFDTData data = {
+        .fdt = fdt,
+        .irq_start = irq_start,
+        .pbus_node_name = node,
+        .pbus = pbus,
+    };
+
+    /* Loop through all dynamic sysbus devices and create their node */
+    foreach_dynamic_sysbus_device(add_fdt_node, &data);
+
+    g_free(node);
+}
+
+static void platform_bus_fdt_notify(Notifier *notifier, void *data)
+{
+    PlatformBusFDTNotifierParams *p = DO_UPCAST(PlatformBusFDTNotifierParams,
+                                                notifier, notifier);
+
+    add_all_platform_bus_fdt_nodes(p->fdt_params);
+    g_free(p->fdt_params);
+    g_free(p);
+}
+
+void arm_register_platform_bus_fdt_creator(ARMPlatformBusFDTParams *fdt_params)
+{
+    PlatformBusFDTNotifierParams *p = g_new(PlatformBusFDTNotifierParams, 1);
+
+    p->fdt_params = fdt_params;
+    p->notifier.notify = platform_bus_fdt_notify;
+    qemu_add_machine_init_done_notifier(&p->notifier);
+}