1 files changed, 116 insertions, 0 deletions

diff --git a/arch/tile/kernel/messaging.c b/arch/tile/kernel/messaging.c
new file mode 100644
index 000000000000..6d23ed271d10
--- /dev/null
+++ b/arch/tile/kernel/messaging.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   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, version 2.
+ *
+ *   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, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/percpu.h>
+#include <linux/smp.h>
+#include <linux/hardirq.h>
+#include <linux/ptrace.h>
+#include <asm/hv_driver.h>
+#include <asm/irq_regs.h>
+#include <asm/traps.h>
+#include <hv/hypervisor.h>
+#include <arch/interrupts.h>
+
+/* All messages are stored here */
+static DEFINE_PER_CPU(HV_MsgState, msg_state);
+
+void __cpuinit init_messaging(void)
+{
+        /* Allocate storage for messages in kernel space */
+        HV_MsgState *state = &__get_cpu_var(msg_state);
+        int rc = hv_register_message_state(state);
+        if (rc != HV_OK)
+                panic("hv_register_message_state: error %d", rc);
+
+        /* Make sure downcall interrupts will be enabled. */
+        raw_local_irq_unmask(INT_INTCTRL_1);
+}
+
+void hv_message_intr(struct pt_regs *regs, int intnum)
+{
+        /*
+         * We enter with interrupts disabled and leave them disabled,
+         * to match expectations of called functions (e.g.
+         * do_ccupdate_local() in mm/slab.c).  This is also consistent
+         * with normal call entry for device interrupts.
+         */
+
+        int message[HV_MAX_MESSAGE_SIZE/sizeof(int)];
+        HV_RcvMsgInfo rmi;
+        int nmsgs = 0;
+
+        /* Track time spent here in an interrupt context */
+        struct pt_regs *old_regs = set_irq_regs(regs);
+        irq_enter();
+
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+        /* Debugging check for stack overflow: less than 1/8th stack free? */
+        {
+                long sp = stack_pointer - (long) current_thread_info();
+                if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
+                        pr_emerg("hv_message_intr: "
+                               "stack overflow: %ld\n",
+                               sp - sizeof(struct thread_info));
+                        dump_stack();
+                }
+        }
+#endif
+
+        while (1) {
+                rmi = hv_receive_message(__get_cpu_var(msg_state),
+                                         (HV_VirtAddr) message,
+                                         sizeof(message));
+                if (rmi.msglen == 0)
+                        break;
+
+                if (rmi.msglen < 0)
+                        panic("hv_receive_message failed: %d", rmi.msglen);
+
+                ++nmsgs;
+
+                if (rmi.source == HV_MSG_TILE) {
+                        int tag;
+
+                        /* we just send tags for now */
+                        BUG_ON(rmi.msglen != sizeof(int));
+
+                        tag = message[0];
+#ifdef CONFIG_SMP
+                        evaluate_message(message[0]);
+#else
+                        panic("Received IPI message %d in UP mode", tag);
+#endif
+                } else if (rmi.source == HV_MSG_INTR) {
+                        HV_IntrMsg *him = (HV_IntrMsg *)message;
+                        struct hv_driver_cb *cb =
+                                (struct hv_driver_cb *)him->intarg;
+                        cb->callback(cb, him->intdata);
+                        __get_cpu_var(irq_stat).irq_hv_msg_count++;
+                }
+        }
+
+        /*
+         * We shouldn't have gotten a message downcall with no
+         * messages available.
+         */
+        if (nmsgs == 0)
+                panic("Message downcall invoked with no messages!");
+
+        /*
+         * Track time spent against the current process again and
+         * process any softirqs if they are waiting.
+         */
+        irq_exit();
+        set_irq_regs(old_regs);
+}