[POWERPC] iseries: A new iSeries console

This driver uses the hvc_console.c infrastructure that is used by the
pSeries virtual and RTAS consoles.  This will allow us to make viocons.c
obsolete and is another step along the way to a combined kernel (as
viocons could not coexist with CONFIG_VT).

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

1 files changed, 593 insertions, 0 deletions

diff --git a/drivers/char/hvc_iseries.c b/drivers/char/hvc_iseries.c
new file mode 100644
index 000000000000..256afc8e5838
--- /dev/null
+++ b/drivers/char/hvc_iseries.c
@@ -0,0 +1,593 @@
+/*
+ * iSeries vio driver interface to hvc_console.c
+ *
+ * This code is based heavily on hvc_vio.c and viocons.c
+ *
+ * Copyright (C) 2006 Stephen Rothwell, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+#include <stdarg.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/console.h>
+
+#include <asm/hvconsole.h>
+#include <asm/vio.h>
+#include <asm/prom.h>
+#include <asm/iseries/vio.h>
+#include <asm/iseries/hv_call.h>
+#include <asm/iseries/hv_lp_config.h>
+#include <asm/iseries/hv_lp_event.h>
+
+#include "hvc_console.h"
+
+#define VTTY_PORTS 10
+
+static DEFINE_SPINLOCK(consolelock);
+static DEFINE_SPINLOCK(consoleloglock);
+
+static const char hvc_driver_name[] = "hvc_console";
+
+#define IN_BUF_SIZE     200
+
+/*
+ * Our port information.
+ */
+static struct port_info {
+        HvLpIndex lp;
+        u64 seq;        /* sequence number of last HV send */
+        u64 ack;        /* last ack from HV */
+        struct hvc_struct *hp;
+        int in_start;
+        int in_end;
+        unsigned char in_buf[IN_BUF_SIZE];
+} port_info[VTTY_PORTS] = {
+        [ 0 ... VTTY_PORTS - 1 ] = {
+                .lp = HvLpIndexInvalid
+        }
+};
+
+#define viochar_is_console(pi)  ((pi) == &port_info[0])
+
+static struct vio_device_id hvc_driver_table[] __devinitdata = {
+        {"serial", "IBM,iSeries-vty"},
+        { "", "" }
+};
+MODULE_DEVICE_TABLE(vio, hvc_driver_table);
+
+static void hvlog(char *fmt, ...)
+{
+        int i;
+        unsigned long flags;
+        va_list args;
+        static char buf[256];
+
+        spin_lock_irqsave(&consoleloglock, flags);
+        va_start(args, fmt);
+        i = vscnprintf(buf, sizeof(buf) - 1, fmt, args);
+        va_end(args);
+        buf[i++] = '\r';
+        HvCall_writeLogBuffer(buf, i);
+        spin_unlock_irqrestore(&consoleloglock, flags);
+}
+
+/*
+ * Initialize the common fields in a charLpEvent
+ */
+static void init_data_event(struct viocharlpevent *viochar, HvLpIndex lp)
+{
+        struct HvLpEvent *hev = &viochar->event;
+
+        memset(viochar, 0, sizeof(struct viocharlpevent));
+
+        hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DEFERRED_ACK |
+                HV_LP_EVENT_INT;
+        hev->xType = HvLpEvent_Type_VirtualIo;
+        hev->xSubtype = viomajorsubtype_chario | viochardata;
+        hev->xSourceLp = HvLpConfig_getLpIndex();
+        hev->xTargetLp = lp;
+        hev->xSizeMinus1 = sizeof(struct viocharlpevent);
+        hev->xSourceInstanceId = viopath_sourceinst(lp);
+        hev->xTargetInstanceId = viopath_targetinst(lp);
+}
+
+static int get_chars(uint32_t vtermno, char *buf, int count)
+{
+        struct port_info *pi;
+        int n = 0;
+        unsigned long flags;
+
+        if (vtermno >= VTTY_PORTS)
+                return -EINVAL;
+        if (count == 0)
+                return 0;
+
+        pi = &port_info[vtermno];
+        spin_lock_irqsave(&consolelock, flags);
+
+        if (pi->in_end == 0)
+                goto done;
+
+        n = pi->in_end - pi->in_start;
+        if (n > count)
+                n = count;
+        memcpy(buf, &pi->in_buf[pi->in_start], n);
+        pi->in_start += n;
+        if (pi->in_start == pi->in_end) {
+                pi->in_start = 0;
+                pi->in_end = 0;
+        }
+done:
+        spin_unlock_irqrestore(&consolelock, flags);
+        return n;
+}
+
+static int put_chars(uint32_t vtermno, const char *buf, int count)
+{
+        struct viocharlpevent *viochar;
+        struct port_info *pi;
+        HvLpEvent_Rc hvrc;
+        unsigned long flags;
+        int sent = 0;
+
+        if (vtermno >= VTTY_PORTS)
+                return -EINVAL;
+
+        pi = &port_info[vtermno];
+
+        spin_lock_irqsave(&consolelock, flags);
+
+        if (viochar_is_console(pi) && !viopath_isactive(pi->lp)) {
+                spin_lock_irqsave(&consoleloglock, flags);
+                HvCall_writeLogBuffer(buf, count);
+                spin_unlock_irqrestore(&consoleloglock, flags);
+                sent = count;
+                goto done;
+        }
+
+        viochar = vio_get_event_buffer(viomajorsubtype_chario);
+        if (viochar == NULL) {
+                hvlog("\n\rviocons: Can't get viochar buffer.");
+                goto done;
+        }
+
+        while ((count > 0) && ((pi->seq - pi->ack) < VIOCHAR_WINDOW)) {
+                int len;
+
+                len = (count > VIOCHAR_MAX_DATA) ? VIOCHAR_MAX_DATA : count;
+
+                if (viochar_is_console(pi)) {
+                        spin_lock_irqsave(&consoleloglock, flags);
+                        HvCall_writeLogBuffer(buf, len);
+                        spin_unlock_irqrestore(&consoleloglock, flags);
+                }
+
+                init_data_event(viochar, pi->lp);
+
+                viochar->len = len;
+                viochar->event.xCorrelationToken = pi->seq++;
+                viochar->event.xSizeMinus1 =
+                        offsetof(struct viocharlpevent, data) + len;
+
+                memcpy(viochar->data, buf, len);
+
+                hvrc = HvCallEvent_signalLpEvent(&viochar->event);
+                if (hvrc)
+                        hvlog("\n\rerror sending event! return code %d\n\r",
+                                (int)hvrc);
+                sent += len;
+                count -= len;
+                buf += len;
+        }
+
+        vio_free_event_buffer(viomajorsubtype_chario, viochar);
+done:
+        spin_unlock_irqrestore(&consolelock, flags);
+        return sent;
+}
+
+static struct hv_ops hvc_get_put_ops = {
+        .get_chars = get_chars,
+        .put_chars = put_chars,
+};
+
+static int __devinit hvc_vio_probe(struct vio_dev *vdev,
+                        const struct vio_device_id *id)
+{
+        struct hvc_struct *hp;
+        struct port_info *pi;
+
+        /* probed with invalid parameters. */
+        if (!vdev || !id)
+                return -EPERM;
+
+        if (vdev->unit_address >= VTTY_PORTS)
+                return -ENODEV;
+
+        pi = &port_info[vdev->unit_address];
+
+        hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops);
+        if (IS_ERR(hp))
+                return PTR_ERR(hp);
+        pi->hp = hp;
+        dev_set_drvdata(&vdev->dev, pi);
+
+        return 0;
+}
+
+static int __devexit hvc_vio_remove(struct vio_dev *vdev)
+{
+        struct port_info *pi = dev_get_drvdata(&vdev->dev);
+        struct hvc_struct *hp = pi->hp;
+
+        return hvc_remove(hp);
+}
+
+static struct vio_driver hvc_vio_driver = {
+        .id_table       = hvc_driver_table,
+        .probe          = hvc_vio_probe,
+        .remove         = hvc_vio_remove,
+        .driver         = {
+                .name   = hvc_driver_name,
+                .owner  = THIS_MODULE,
+        }
+};
+
+static void hvc_open_event(struct HvLpEvent *event)
+{
+        unsigned long flags;
+        struct viocharlpevent *cevent = (struct viocharlpevent *)event;
+        u8 port = cevent->virtual_device;
+        struct port_info *pi;
+        int reject = 0;
+
+        if (hvlpevent_is_ack(event)) {
+                if (port >= VTTY_PORTS)
+                        return;
+
+                spin_lock_irqsave(&consolelock, flags);
+
+                pi = &port_info[port];
+                if (event->xRc == HvLpEvent_Rc_Good) {
+                        pi->seq = pi->ack = 0;
+                        /*
+                         * This line allows connections from the primary
+                         * partition but once one is connected from the
+                         * primary partition nothing short of a reboot
+                         * of linux will allow access from the hosting
+                         * partition again without a required iSeries fix.
+                         */
+                        pi->lp = event->xTargetLp;
+                }
+
+                spin_unlock_irqrestore(&consolelock, flags);
+                if (event->xRc != HvLpEvent_Rc_Good)
+                        printk(KERN_WARNING
+                               "hvc: handle_open_event: event->xRc == (%d).\n",
+                               event->xRc);
+
+                if (event->xCorrelationToken != 0) {
+                        atomic_t *aptr= (atomic_t *)event->xCorrelationToken;
+                        atomic_set(aptr, 1);
+                } else
+                        printk(KERN_WARNING
+                               "hvc: weird...got open ack without atomic\n");
+                return;
+        }
+
+        /* This had better require an ack, otherwise complain */
+        if (!hvlpevent_need_ack(event)) {
+                printk(KERN_WARNING "hvc: viocharopen without ack bit!\n");
+                return;
+        }
+
+        spin_lock_irqsave(&consolelock, flags);
+
+        /* Make sure this is a good virtual tty */
+        if (port >= VTTY_PORTS) {
+                event->xRc = HvLpEvent_Rc_SubtypeError;
+                cevent->subtype_result_code = viorc_openRejected;
+                /*
+                 * Flag state here since we can't printk while holding
+                 * the consolelock spinlock.
+                 */
+                reject = 1;
+        } else {
+                pi = &port_info[port];
+                if ((pi->lp != HvLpIndexInvalid) &&
+                                (pi->lp != event->xSourceLp)) {
+                        /*
+                         * If this is tty is already connected to a different
+                         * partition, fail.
+                         */
+                        event->xRc = HvLpEvent_Rc_SubtypeError;
+                        cevent->subtype_result_code = viorc_openRejected;
+                        reject = 2;
+                } else {
+                        pi->lp = event->xSourceLp;
+                        event->xRc = HvLpEvent_Rc_Good;
+                        cevent->subtype_result_code = viorc_good;
+                        pi->seq = pi->ack = 0;
+                }
+        }
+
+        spin_unlock_irqrestore(&consolelock, flags);
+
+        if (reject == 1)
+                printk(KERN_WARNING "hvc: open rejected: bad virtual tty.\n");
+        else if (reject == 2)
+                printk(KERN_WARNING "hvc: open rejected: console in exclusive "
+                                "use by another partition.\n");
+
+        /* Return the acknowledgement */
+        HvCallEvent_ackLpEvent(event);
+}
+
+/*
+ * Handle a close charLpEvent.  This should ONLY be an Interrupt because the
+ * virtual console should never actually issue a close event to the hypervisor
+ * because the virtual console never goes away.  A close event coming from the
+ * hypervisor simply means that there are no client consoles connected to the
+ * virtual console.
+ */
+static void hvc_close_event(struct HvLpEvent *event)
+{
+        unsigned long flags;
+        struct viocharlpevent *cevent = (struct viocharlpevent *)event;
+        u8 port = cevent->virtual_device;
+
+        if (!hvlpevent_is_int(event)) {
+                printk(KERN_WARNING
+                        "hvc: got unexpected close acknowlegement\n");
+                return;
+        }
+
+        if (port >= VTTY_PORTS) {
+                printk(KERN_WARNING
+                        "hvc: close message from invalid virtual device.\n");
+                return;
+        }
+
+        /* For closes, just mark the console partition invalid */
+        spin_lock_irqsave(&consolelock, flags);
+
+        if (port_info[port].lp == event->xSourceLp)
+                port_info[port].lp = HvLpIndexInvalid;
+
+        spin_unlock_irqrestore(&consolelock, flags);
+}
+
+static void hvc_data_event(struct HvLpEvent *event)
+{
+        unsigned long flags;
+        struct viocharlpevent *cevent = (struct viocharlpevent *)event;
+        struct port_info *pi;
+        int n;
+        u8 port = cevent->virtual_device;
+
+        if (port >= VTTY_PORTS) {
+                printk(KERN_WARNING "hvc: data on invalid virtual device %d\n",
+                                port);
+                return;
+        }
+        if (cevent->len == 0)
+                return;
+
+        /*
+         * Change 05/01/2003 - Ryan Arnold: If a partition other than
+         * the current exclusive partition tries to send us data
+         * events then just drop them on the floor because we don't
+         * want his stinking data.  He isn't authorized to receive
+         * data because he wasn't the first one to get the console,
+         * therefore he shouldn't be allowed to send data either.
+         * This will work without an iSeries fix.
+         */
+        pi = &port_info[port];
+        if (pi->lp != event->xSourceLp)
+                return;
+
+        spin_lock_irqsave(&consolelock, flags);
+
+        n = IN_BUF_SIZE - pi->in_end;
+        if (n > cevent->len)
+                n = cevent->len;
+        if (n > 0) {
+                memcpy(&pi->in_buf[pi->in_end], cevent->data, n);
+                pi->in_end += n;
+        }
+        spin_unlock_irqrestore(&consolelock, flags);
+        if (n == 0)
+                printk(KERN_WARNING "hvc: input buffer overflow\n");
+}
+
+static void hvc_ack_event(struct HvLpEvent *event)
+{
+        struct viocharlpevent *cevent = (struct viocharlpevent *)event;
+        unsigned long flags;
+        u8 port = cevent->virtual_device;
+
+        if (port >= VTTY_PORTS) {
+                printk(KERN_WARNING "hvc: data on invalid virtual device\n");
+                return;
+        }
+
+        spin_lock_irqsave(&consolelock, flags);
+        port_info[port].ack = event->xCorrelationToken;
+        spin_unlock_irqrestore(&consolelock, flags);
+}
+
+static void hvc_config_event(struct HvLpEvent *event)
+{
+        struct viocharlpevent *cevent = (struct viocharlpevent *)event;
+
+        if (cevent->data[0] == 0x01)
+                printk(KERN_INFO "hvc: window resized to %d: %d: %d: %d\n",
+                       cevent->data[1], cevent->data[2],
+                       cevent->data[3], cevent->data[4]);
+        else
+                printk(KERN_WARNING "hvc: unknown config event\n");
+}
+
+static void hvc_handle_event(struct HvLpEvent *event)
+{
+        int charminor;
+
+        if (event == NULL)
+                return;
+
+        charminor = event->xSubtype & VIOMINOR_SUBTYPE_MASK;
+        switch (charminor) {
+        case viocharopen:
+                hvc_open_event(event);
+                break;
+        case viocharclose:
+                hvc_close_event(event);
+                break;
+        case viochardata:
+                hvc_data_event(event);
+                break;
+        case viocharack:
+                hvc_ack_event(event);
+                break;
+        case viocharconfig:
+                hvc_config_event(event);
+                break;
+        default:
+                if (hvlpevent_is_int(event) && hvlpevent_need_ack(event)) {
+                        event->xRc = HvLpEvent_Rc_InvalidSubtype;
+                        HvCallEvent_ackLpEvent(event);
+                }
+        }
+}
+
+static int send_open(HvLpIndex remoteLp, void *sem)
+{
+        return HvCallEvent_signalLpEventFast(remoteLp,
+                        HvLpEvent_Type_VirtualIo,
+                        viomajorsubtype_chario | viocharopen,
+                        HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
+                        viopath_sourceinst(remoteLp),
+                        viopath_targetinst(remoteLp),
+                        (u64)(unsigned long)sem, VIOVERSION << 16,
+                        0, 0, 0, 0);
+}
+
+static int hvc_vio_init(void)
+{
+        atomic_t wait_flag;
+        int rc;
+
+        /* +2 for fudge */
+        rc = viopath_open(HvLpConfig_getPrimaryLpIndex(),
+                        viomajorsubtype_chario, VIOCHAR_WINDOW + 2);
+        if (rc)
+                printk(KERN_WARNING "hvc: error opening to primary %d\n", rc);
+
+        if (viopath_hostLp == HvLpIndexInvalid)
+                vio_set_hostlp();
+
+        /*
+         * And if the primary is not the same as the hosting LP, open to the
+         * hosting lp
+         */
+        if ((viopath_hostLp != HvLpIndexInvalid) &&
+            (viopath_hostLp != HvLpConfig_getPrimaryLpIndex())) {
+                printk(KERN_INFO "hvc: open path to hosting (%d)\n",
+                                viopath_hostLp);
+                rc = viopath_open(viopath_hostLp, viomajorsubtype_chario,
+                                VIOCHAR_WINDOW + 2);    /* +2 for fudge */
+                if (rc)
+                        printk(KERN_WARNING
+                                "error opening to partition %d: %d\n",
+                                viopath_hostLp, rc);
+        }
+
+        if (vio_setHandler(viomajorsubtype_chario, hvc_handle_event) < 0)
+                printk(KERN_WARNING
+                        "hvc: error seting handler for console events!\n");
+
+        /*
+         * First, try to open the console to the hosting lp.
+         * Wait on a semaphore for the response.
+         */
+        atomic_set(&wait_flag, 0);
+        if ((viopath_isactive(viopath_hostLp)) &&
+            (send_open(viopath_hostLp, &wait_flag) == 0)) {
+                printk(KERN_INFO "hvc: hosting partition %d\n", viopath_hostLp);
+                while (atomic_read(&wait_flag) == 0)
+                        mb();
+                atomic_set(&wait_flag, 0);
+        }
+
+        /*
+         * If we don't have an active console, try the primary
+         */
+        if ((!viopath_isactive(port_info[0].lp)) &&
+            (viopath_isactive(HvLpConfig_getPrimaryLpIndex())) &&
+            (send_open(HvLpConfig_getPrimaryLpIndex(), &wait_flag) == 0)) {
+                printk(KERN_INFO "hvc: opening console to primary partition\n");
+                while (atomic_read(&wait_flag) == 0)
+                        mb();
+        }
+
+        /* Register as a vio device to receive callbacks */
+        rc = vio_register_driver(&hvc_vio_driver);
+
+        return rc;
+}
+module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
+
+static void hvc_vio_exit(void)
+{
+        vio_unregister_driver(&hvc_vio_driver);
+}
+module_exit(hvc_vio_exit);
+
+/* the device tree order defines our numbering */
+static int hvc_find_vtys(void)
+{
+        struct device_node *vty;
+        int num_found = 0;
+
+        for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL;
+                        vty = of_find_node_by_name(vty, "vty")) {
+                uint32_t *vtermno;
+
+                /* We have statically defined space for only a certain number
+                 * of console adapters.
+                 */
+                if ((num_found >= MAX_NR_HVC_CONSOLES) ||
+                                (num_found >= VTTY_PORTS))
+                        break;
+
+                vtermno = (uint32_t *)get_property(vty, "reg", NULL);
+                if (!vtermno)
+                        continue;
+
+                if (!device_is_compatible(vty, "IBM,iSeries-vty"))
+                        continue;
+
+                if (num_found == 0)
+                        add_preferred_console("hvc", 0, NULL);
+                hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops);
+                ++num_found;
+        }
+
+        return num_found;
+}
+console_initcall(hvc_find_vtys);