s390/sclplmconsole: Add support for SCLP line-mode console

Add simple support for SCLP line-mode also known as operating
system messages. This can be added in addition to or instead of
the SCLP full screen console with -device sclplmconsole.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

2 files changed, 399 insertions, 1 deletions

diff --git a/hw/char/Makefile.objs b/hw/char/Makefile.objs
index f8f3dbca3e..cbd6a006f4 100644
--- a/hw/char/Makefile.objs
+++ b/hw/char/Makefile.objs
@@ -22,6 +22,6 @@ common-obj-$(CONFIG_IMX) += imx_serial.o
 common-obj-$(CONFIG_LM32) += lm32_juart.o
 common-obj-$(CONFIG_LM32) += lm32_uart.o
 common-obj-$(CONFIG_MILKYMIST) += milkymist-uart.o
-common-obj-$(CONFIG_SCLPCONSOLE) += sclpconsole.o
+common-obj-$(CONFIG_SCLPCONSOLE) += sclpconsole.o sclpconsole-lm.o
 
 obj-$(CONFIG_VIRTIO) += virtio-serial-bus.o
diff --git a/hw/char/sclpconsole-lm.c b/hw/char/sclpconsole-lm.c
new file mode 100644
index 0000000000..93390675d6
--- /dev/null
+++ b/hw/char/sclpconsole-lm.c
@@ -0,0 +1,398 @@
+/*
+ * SCLP event types
+ *    Operations Command - Line Mode input
+ *    Message            - Line Mode output
+ *
+ * Copyright IBM, Corp. 2013
+ *
+ * Authors:
+ *  Heinz Graalfs <graalfs@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at your
+ * option) any later version.  See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "hw/qdev.h"
+#include "qemu/thread.h"
+#include "qemu/error-report.h"
+#include "sysemu/char.h"
+
+#include "hw/s390x/sclp.h"
+#include "hw/s390x/event-facility.h"
+#include "hw/s390x/ebcdic.h"
+
+#define SIZE_BUFFER 4096
+#define NEWLINE     "\n"
+
+typedef struct OprtnsCommand {
+    EventBufferHeader header;
+    MDMSU message_unit;
+    char data[0];
+} QEMU_PACKED OprtnsCommand;
+
+/* max size for line-mode data in 4K SCCB page */
+#define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))
+
+typedef struct SCLPConsoleLM {
+    SCLPEvent event;
+    CharDriverState *chr;
+    bool echo;                  /* immediate echo of input if true        */
+    uint32_t write_errors;      /* errors writing to char layer           */
+    uint32_t length;            /* length of byte stream in buffer        */
+    uint8_t buf[SIZE_CONSOLE_BUFFER];
+    qemu_irq irq_console_read;
+} SCLPConsoleLM;
+
+/*
+*  Character layer call-back functions
+ *
+ * Allow 1 character at a time
+ *
+ * Accumulate bytes from character layer in console buffer,
+ * event_pending is set when a newline character is encountered
+ *
+ * The maximum command line length is limited by the maximum
+ * space available in an SCCB
+ */
+
+static int chr_can_read(void *opaque)
+{
+    SCLPConsoleLM *scon = opaque;
+
+    if (scon->event.event_pending) {
+        return 0;
+    } else if (SIZE_CONSOLE_BUFFER - scon->length) {
+        return 1;
+    }
+    return 0;
+}
+
+static void receive_from_chr_layer(SCLPConsoleLM *scon, const uint8_t *buf,
+                                   int size)
+{
+    assert(size == 1);
+
+    if (*buf == '\r' || *buf == '\n') {
+        scon->event.event_pending = true;
+        return;
+    }
+    scon->buf[scon->length] = *buf;
+    scon->length += 1;
+    if (scon->echo) {
+        qemu_chr_fe_write(scon->chr, buf, size);
+    }
+}
+
+/*
+ * Send data from a char device over to the guest
+ */
+static void chr_read(void *opaque, const uint8_t *buf, int size)
+{
+    SCLPConsoleLM *scon = opaque;
+
+    receive_from_chr_layer(scon, buf, size);
+    if (scon->event.event_pending) {
+        /* trigger SCLP read operation */
+        qemu_irq_raise(scon->irq_console_read);
+    }
+}
+
+/* functions to be called by event facility */
+
+static bool can_handle_event(uint8_t type)
+{
+    return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
+}
+
+static unsigned int send_mask(void)
+{
+    return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
+}
+
+static unsigned int receive_mask(void)
+{
+    return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
+}
+
+/*
+ * Triggered by SCLP's read_event_data
+ * - convert ASCII byte stream to EBCDIC and
+ * - copy converted data into provided (SCLP) buffer
+ */
+static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
+                            int avail)
+{
+    int len;
+
+    SCLPConsoleLM *cons = DO_UPCAST(SCLPConsoleLM, event, event);
+
+    len = cons->length;
+    /* data need to fit into provided SCLP buffer */
+    if (len > avail) {
+        return 1;
+    }
+
+    ebcdic_put(buf, (char *)&cons->buf, len);
+    *size = len;
+    cons->length = 0;
+    /* data provided and no more data pending */
+    event->event_pending = false;
+    return 0;
+}
+
+static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
+                           int *slen)
+{
+    int avail, rc;
+    size_t src_len;
+    uint8_t *to;
+    OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
+
+    if (!event->event_pending) {
+        /* no data pending */
+        return 0;
+    }
+
+    to = (uint8_t *)&oc->data;
+    avail = *slen - sizeof(OprtnsCommand);
+    rc = get_console_data(event, to, &src_len, avail);
+    if (rc) {
+        /* data didn't fit, try next SCCB */
+        return 1;
+    }
+
+    oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
+    oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
+
+    oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
+    oc->message_unit.cpmsu.length =
+        cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
+
+    oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
+    oc->message_unit.text_command.length =
+        cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
+
+    oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
+    oc->message_unit.self_def_text_message.length =
+        cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
+
+    oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
+    oc->message_unit.text_message.length =
+        cpu_to_be16(sizeof(GdsSubvector) + src_len);
+
+    oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
+    oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
+    *slen = avail - src_len;
+
+    return 1;
+}
+
+/*
+ * Triggered by SCLP's write_event_data
+ *  - write console data to character layer
+ *  returns < 0 if an error occurred
+ */
+static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
+{
+    int ret = 0;
+    const uint8_t *buf_offset;
+
+    SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
+
+    if (!scon->chr) {
+        /* If there's no backend, we can just say we consumed all data. */
+        return len;
+    }
+
+    buf_offset = buf;
+    while (len > 0) {
+        ret = qemu_chr_fe_write(scon->chr, buf, len);
+        if (ret == 0) {
+            /* a pty doesn't seem to be connected - no error */
+            len = 0;
+        } else if (ret == -EAGAIN || (ret > 0 && ret < len)) {
+            len -= ret;
+            buf_offset += ret;
+        } else {
+            len = 0;
+        }
+    }
+
+    return ret;
+}
+
+static int process_mdb(SCLPEvent *event, MDBO *mdbo)
+{
+    int rc;
+    int len;
+    uint8_t buffer[SIZE_BUFFER];
+
+    len = be16_to_cpu(mdbo->length);
+    len -= sizeof(mdbo->length) + sizeof(mdbo->type)
+            + sizeof(mdbo->mto.line_type_flags)
+            + sizeof(mdbo->mto.alarm_control)
+            + sizeof(mdbo->mto._reserved);
+
+    assert(len <= SIZE_BUFFER);
+
+    /* convert EBCDIC SCLP contents to ASCII console message */
+    ascii_put(buffer, mdbo->mto.message, len);
+    rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
+    if (rc < 0) {
+        return rc;
+    }
+    return write_console_data(event, buffer, len);
+}
+
+static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
+{
+    int len;
+    int written;
+    int errors = 0;
+    MDBO *mdbo;
+    SclpMsg *data = (SclpMsg *) ebh;
+    SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
+
+    len = be16_to_cpu(data->mdb.header.length);
+    if (len < sizeof(data->mdb.header)) {
+        return SCLP_RC_INCONSISTENT_LENGTHS;
+    }
+    len -= sizeof(data->mdb.header);
+
+    /* first check message buffers */
+    mdbo = data->mdb.mdbo;
+    while (len > 0) {
+        if (be16_to_cpu(mdbo->length) > len
+                || be16_to_cpu(mdbo->length) == 0) {
+            return SCLP_RC_INCONSISTENT_LENGTHS;
+        }
+        len -= be16_to_cpu(mdbo->length);
+        mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
+    }
+
+    /* then execute */
+    len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
+    mdbo = data->mdb.mdbo;
+    while (len > 0) {
+        switch (be16_to_cpu(mdbo->type)) {
+        case MESSAGE_TEXT:
+            /* message text object */
+            written = process_mdb(event, mdbo);
+            if (written < 0) {
+                /* character layer error */
+                errors++;
+            }
+            break;
+        default: /* ignore */
+            break;
+        }
+        len -= be16_to_cpu(mdbo->length);
+        mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
+    }
+    if (errors) {
+        scon->write_errors += errors;
+    }
+    data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
+
+    return SCLP_RC_NORMAL_COMPLETION;
+}
+
+static void trigger_console_data(void *opaque, int n, int level)
+{
+    sclp_service_interrupt(0);
+}
+
+/* functions for live migration */
+
+static const VMStateDescription vmstate_sclplmconsole = {
+    .name = "sclplmconsole",
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .minimum_version_id_old = 0,
+    .fields      = (VMStateField[]) {
+        VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
+        VMSTATE_UINT32(write_errors, SCLPConsoleLM),
+        VMSTATE_UINT32(length, SCLPConsoleLM),
+        VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
+        VMSTATE_END_OF_LIST()
+     }
+};
+
+/* qemu object creation and initialization functions */
+
+/* tell character layer our call-back functions */
+
+static int console_init(SCLPEvent *event)
+{
+    static bool console_available;
+
+    SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
+
+    if (console_available) {
+        error_report("Multiple line-mode operator consoles are not supported");
+        return -1;
+    }
+    console_available = true;
+
+    if (scon->chr) {
+        qemu_chr_add_handlers(scon->chr, chr_can_read, chr_read, NULL, scon);
+    }
+    scon->irq_console_read = *qemu_allocate_irqs(trigger_console_data, NULL, 1);
+
+    return 0;
+}
+
+static int console_exit(SCLPEvent *event)
+{
+    return 0;
+}
+
+static void console_reset(DeviceState *dev)
+{
+   SCLPEvent *event = SCLP_EVENT(dev);
+   SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
+
+   event->event_pending = false;
+   scon->length = 0;
+   scon->write_errors = 0;
+}
+
+static Property console_properties[] = {
+    DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
+    DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
+    DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void console_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
+
+    dc->props = console_properties;
+    dc->reset = console_reset;
+    dc->vmsd = &vmstate_sclplmconsole;
+    ec->init = console_init;
+    ec->exit = console_exit;
+    ec->get_send_mask = send_mask;
+    ec->get_receive_mask = receive_mask;
+    ec->can_handle_event = can_handle_event;
+    ec->read_event_data = read_event_data;
+    ec->write_event_data = write_event_data;
+}
+
+static const TypeInfo sclp_console_info = {
+    .name          = "sclplmconsole",
+    .parent        = TYPE_SCLP_EVENT,
+    .instance_size = sizeof(SCLPConsoleLM),
+    .class_init    = console_class_init,
+    .class_size    = sizeof(SCLPEventClass),
+};
+
+static void register_types(void)
+{
+    type_register_static(&sclp_console_info);
+}
+
+type_init(register_types)