This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / drivers / xen / console / xencons_ring.c

diff --git a/drivers/xen/console/xencons_ring.c b/drivers/xen/console/xencons_ring.c
new file mode 100644 (file)
index 0000000..454fe42
--- /dev/null
+++ b/drivers/xen/console/xencons_ring.c
@@ -0,0 +1,141 @@
+/* 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/major.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+
+#include <asm/hypervisor.h>
+#include <xen/evtchn.h>
+#include <xen/xencons.h>
+#include <linux/wait.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <xen/interface/io/console.h>
+
+static int xencons_irq;
+
+static inline struct xencons_interface *xencons_interface(void)
+{
+       return mfn_to_virt(xen_start_info->console_mfn);
+}
+
+static inline void notify_daemon(void)
+{
+       /* Use evtchn: this is called early, before irq is set up. */
+       notify_remote_via_evtchn(xen_start_info->console_evtchn);
+}
+
+int xencons_ring_send(const char *data, unsigned len)
+{
+       int sent = 0;
+       struct xencons_interface *intf = xencons_interface();
+       XENCONS_RING_IDX cons, prod;
+
+       cons = intf->out_cons;
+       prod = intf->out_prod;
+       mb();
+       BUG_ON((prod - cons) > sizeof(intf->out));
+
+       while ((sent < len) && ((prod - cons) < sizeof(intf->out)))
+               intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++];
+
+       wmb();
+       intf->out_prod = prod;
+
+       notify_daemon();
+
+       return sent;
+}
+
+static irqreturn_t handle_input(int irq, void *unused, struct pt_regs *regs)
+{
+       struct xencons_interface *intf = xencons_interface();
+       XENCONS_RING_IDX cons, prod;
+
+       cons = intf->in_cons;
+       prod = intf->in_prod;
+       mb();
+       BUG_ON((prod - cons) > sizeof(intf->in));
+
+       while (cons != prod) {
+               xencons_rx(intf->in+MASK_XENCONS_IDX(cons,intf->in), 1, regs);
+               cons++;
+       }
+
+       mb();
+       intf->in_cons = cons;
+
+       notify_daemon();
+
+       xencons_tx();
+
+       return IRQ_HANDLED;
+}
+
+int xencons_ring_init(void)
+{
+       int err;
+
+       if (xencons_irq)
+               unbind_from_irqhandler(xencons_irq, NULL);
+       xencons_irq = 0;
+
+       if (!xen_start_info->console_evtchn)
+               return 0;
+
+       err = bind_evtchn_to_irqhandler(
+               xen_start_info->console_evtchn,
+               handle_input, 0, "xencons", NULL);
+       if (err <= 0) {
+               printk(KERN_ERR "XEN console request irq failed %i\n", err);
+               return err;
+       }
+
+       xencons_irq = err;
+
+       /* In case we have in-flight data after save/restore... */
+       notify_daemon();
+
+       return 0;
+}
+
+void xencons_resume(void)
+{
+       (void)xencons_ring_init();
+}