[Qemu-devel] [RFC v3 6/6] hw/misc: sdm communication socket

[Christian Pinto <c.pinto@virtualopensystems.com>]

From: Baptiste Reynal <b.reynal@virtualopensystems.com>

This is the socket implementation of an SDM communication channel. A
master device can communicate with a slave over a socket.

Parameters:
    socket=[socket_id] - specifies the multi-client socket

This patch depends on "[RFC v2 1/1] backend: multi-client-socket"

Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Christian Pinto <c.pinto@virtualopensystems.com>

---
v2 -> v3:
- added sdm_socket_update_num_slaves to socket based communication channel
- realloc slaves array in case of max slaves num change
---
 hw/misc/Makefile.objs                      |   1 +
 hw/misc/sdm-communication-socket.c         | 160 +++++++++++++++++++++++++++++
 include/hw/misc/sdm-communication-socket.h |  42 ++++++++
 3 files changed, 203 insertions(+)
 create mode 100644 hw/misc/sdm-communication-socket.c
 create mode 100644 include/hw/misc/sdm-communication-socket.h

diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index cad0b4c..8f38d35 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -26,6 +26,7 @@ obj-$(CONFIG_SDM) += sdm-communication.o
 obj-$(CONFIG_SDM) += sdm-signal.o
 obj-$(CONFIG_SDM) += sdm-platform.o
 obj-$(CONFIG_SDM) += sdm-communication-local.o
+obj-$(CONFIG_SDM) += sdm-communication-socket.o
 
 obj-$(CONFIG_REALVIEW) += arm_sysctl.o
 obj-$(CONFIG_NSERIES) += cbus.o
diff --git a/hw/misc/sdm-communication-socket.c b/hw/misc/sdm-communication-socket.c
new file mode 100644
index 0000000..15ebed7
--- /dev/null
+++ b/hw/misc/sdm-communication-socket.c
@@ -0,0 +1,160 @@
+/*
+ * SDM Communication Socket
+ *
+ * Copyright (C) 2016 - Virtual Open Systems
+ *
+ * Author: Baptiste Reynal <b.reynal@virtualopensystems.com>
+ *	   Christian Pinto <c.pinto@virtualopensystems.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+#include "hw/misc/sdm-communication-socket.h"
+#include "hw/qdev-properties.h"
+#include "qemu/error-report.h"
+
+static int sdm_socket_signal(SDMCommunication *sdmc, SDMDevice *sdm,
+        SDMSignalData *signal)
+{
+    SDMCommunicationSocket *sdmcs = SDM_COMMUNICATION_SOCKET(sdmc);
+    int len;
+    char *message;
+    SDMSignalData *payload;
+
+    if (!sdmcs->slaves[signal->slave]) {
+        error_report("SDMCommunicationSocket: invalid slave ID %d",
+                signal->slave);
+        return -1;
+    }
+
+    len = strlen(SDM_SIGNAL_CMD) + sizeof(SDMSignalData) + 1;
+    message = malloc(len);
+
+    strcpy((char *) message, SDM_SIGNAL_CMD);
+    payload = (SDMSignalData *) (message + strlen(SDM_SIGNAL_CMD) + 1);
+    memcpy(payload, signal, sizeof(SDMSignalData));
+
+    multi_socket_write_to(sdmcs->slaves[signal->slave],
+            message,
+            len);
+
+    return 0;
+}
+
+static void sdm_register_ms_handler(MSClient *c, const char *message,
+        void *opaque)
+{
+    SDMCommunication *sdmc = opaque;
+    SDMCommunicationSocket *sdmcs = SDM_COMMUNICATION_SOCKET(sdmc);
+    int slave_id;
+
+    slave_id = sdm_device_accept(sdmcs->master);
+    if (slave_id >= 0) {
+        sdmcs->slaves[slave_id] = c;
+    } else {
+        error_report("SDMCommunicationSocket: Slave rejected, no ID available");
+    }
+}
+
+static void sdm_signal_ms_handler(MSClient *c, const char *message,
+        void *opaque)
+{
+    SDMCommunication *sdmc = opaque;
+    SDMCommunicationSocket *sdmcs = SDM_COMMUNICATION_SOCKET(sdmc);
+    int slave;
+    SDMSignalData *signal;
+
+    signal = (SDMSignalData *) message;
+
+    /* Find slave id */
+    for (slave=0; slave<=sdmcs->num_slaves; slave++) {
+        if (sdmcs->slaves[slave] == c)
+            break;
+    }
+
+    signal->slave = slave;
+
+    while (sdm_device_notify(sdmcs->master, signal) < 0) {
+        sleep(100);
+    }
+}
+
+static int sdm_socket_connect(SDMCommunication *sdmc, SDMDevice *sdm)
+{
+    SDMCommunicationSocket *sdmcs = SDM_COMMUNICATION_SOCKET(sdmc);
+
+    sdmcs->master = sdm;
+
+    sdmcs->num_slaves = sdm_device_get_num_slaves(sdm);
+    sdmcs->slaves = calloc(sdmcs->num_slaves + 1,
+            sizeof(MSClient *));
+
+    sdmcs->slaves[0] = &sdmcs->socket->listener;
+    multi_socket_add_handler(sdmcs->socket, SDM_SIGNAL_CMD,
+            sdm_signal_ms_handler, sdmc);
+
+    if (sdm_device_is_master(sdm)) {
+        multi_socket_add_handler(sdmcs->socket, SDM_REGISTER_CMD,
+                sdm_register_ms_handler, sdmc);
+    } else {
+        multi_socket_write_to(sdmcs->slaves[0],
+                SDM_REGISTER_CMD,
+                strlen(SDM_REGISTER_CMD) + 1);
+    }
+
+    return 0;
+}
+
+static int sdm_socket_update_num_slaves(SDMCommunication *sdmc, SDMDevice *sdm,
+            uint16_t num_slaves)
+{
+    SDMCommunicationSocket *sdmcs = SDM_COMMUNICATION_SOCKET(sdmc);
+    MSClient **tmp_slaves;
+
+    tmp_slaves = realloc(sdmcs->slaves, (num_slaves + 1) *
+                sizeof(MSClient *));
+
+    if(tmp_slaves == NULL)
+        return -1;
+
+    sdmcs->slaves = tmp_slaves;
+    sdmcs->num_slaves = num_slaves;
+    sdm_device_set_num_slaves(sdm, num_slaves);
+
+    return 0;
+}
+
+static void sdm_communication_socket_class_init(ObjectClass *oc, void *data)
+{
+    SDMCommunicationClass *sdmck = SDM_COMMUNICATION_CLASS(oc);
+
+    sdmck->signal = sdm_socket_signal;
+    sdmck->connect = sdm_socket_connect;
+    sdmck->update_num_slaves = sdm_socket_update_num_slaves;
+}
+
+static void sdm_communication_socket_init(Object *obj)
+{
+    SDMCommunicationSocket *s = SDM_COMMUNICATION_SOCKET(obj);
+
+    object_property_add_link(obj, "socket", TYPE_MULTI_SOCKET_BACKEND,
+            (Object **)&s->socket,
+            object_property_allow_set_link,
+            OBJ_PROP_LINK_UNREF_ON_RELEASE,
+            &error_abort);
+}
+
+static const TypeInfo sdm_communication_socket_info = {
+    .name = TYPE_SDM_COMMUNICATION_SOCKET,
+    .parent = TYPE_SDM_COMMUNICATION,
+    .class_init = sdm_communication_socket_class_init,
+    .instance_size = sizeof(SDMCommunicationSocket),
+    .instance_init = sdm_communication_socket_init,
+};
+
+static void register_types(void)
+{
+    type_register_static(&sdm_communication_socket_info);
+}
+
+type_init(register_types);
diff --git a/include/hw/misc/sdm-communication-socket.h b/include/hw/misc/sdm-communication-socket.h
new file mode 100644
index 0000000..aa24454
--- /dev/null
+++ b/include/hw/misc/sdm-communication-socket.h
@@ -0,0 +1,42 @@
+/*
+ * SDM Communication Socket
+ *
+ * Copyright (C) 2016 - Virtual Open Systems
+ *
+ * Author: Baptiste Reynal <b.reynal@virtualopensystems.com>
+ *
+ * This works is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+#ifndef HW_SDM_COMM_SOCK_H
+#define HW_SDM_COMM_SOCK_H
+
+#include "hw/misc/sdm-communication.h"
+#include "qemu/multi-socket.h"
+
+#define SDM_REGISTER_CMD "sdm_register"
+#define SDM_SIGNAL_CMD "sdm_signal"
+
+#define TYPE_SDM_COMMUNICATION_SOCKET "sdm-communication-socket"
+#define SDM_COMMUNICATION_SOCKET(obj) \
+    OBJECT_CHECK(SDMCommunicationSocket, (obj), \
+            TYPE_SDM_COMMUNICATION_SOCKET)
+
+typedef struct SDMCommunicationSocket SDMCommunicationSocket;
+
+/**
+ * @SDMCommunicationSocket
+ *
+ * @parent: opaque parent object container
+ */
+struct SDMCommunicationSocket {
+    /* private */
+    SDMCommunication parent;
+
+    SDMDevice *master;
+    MSBackend *socket;
+
+    int num_slaves;
+    MSClient **slaves;
+};
+#endif
-- 
1.9.1