From 5e0b8d508ed51004bd836384293be00950ee62c9 Mon Sep 17 00:00:00 2001
From: Pasha <pasha@member.fsf.org>
Date: Tue, 20 Feb 2024 18:49:50 +0000
Subject: init gnumach copy

---
 xen/evt.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 119 insertions(+)
 create mode 100644 xen/evt.c

(limited to 'xen/evt.c')

diff --git a/xen/evt.c b/xen/evt.c
new file mode 100644
index 0000000..7296ae4
--- /dev/null
+++ b/xen/evt.c
@@ -0,0 +1,119 @@
+/*
+ *  Copyright (C) 2007-2009 Free Software Foundation
+ *
+ * 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 the program ; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+#include <mach/xen.h>
+#include <machine/xen.h>
+#include <machine/ipl.h>
+#include <machine/gdt.h>
+#include <xen/console.h>
+#include "evt.h"
+
+#define NEVNT (sizeof(unsigned long) * sizeof(unsigned long) * 8)
+int	int_mask[NSPL];
+
+spl_t curr_ipl[NCPUS];
+int spl_init = 0;
+
+interrupt_handler_fn ivect[NEVNT];
+int intpri[NEVNT];
+int iunit[NEVNT];
+
+void hyp_c_callback(void *ret_addr, void *regs)
+{
+	int i, j, n;
+	int cpu = 0;
+	unsigned long pending_sel;
+
+	hyp_shared_info.vcpu_info[cpu].evtchn_upcall_pending = 0;
+	/* no need for a barrier on x86, xchg is already one */
+#if !(defined(__i386__) || defined(__x86_64__))
+	wmb();
+#endif
+	while ((pending_sel = xchgl(&hyp_shared_info.vcpu_info[cpu].evtchn_pending_sel, 0))) {
+
+		for (i = 0; pending_sel; i++, pending_sel >>= 1) {
+			unsigned long pending;
+
+			if (!(pending_sel & 1))
+				continue;
+
+			while ((pending = (hyp_shared_info.evtchn_pending[i] & ~hyp_shared_info.evtchn_mask[i]))) {
+
+				n = i * sizeof(unsigned long);
+				for (j = 0; pending; j++, n++, pending >>= 1) {
+					if (!(pending & 1))
+						continue;
+
+					if (ivect[n]) {
+						spl_t spl = splx(intpri[n]);
+						asm ("lock; and %1,%0":"=m"(hyp_shared_info.evtchn_pending[i]):"r"(~(1UL<<j)));
+						((void(*)(int, int, const char*, struct i386_interrupt_state*))(ivect[n]))(iunit[n], spl, ret_addr, regs);
+						splx_cli(spl);
+					} else {
+						printf("warning: lost unbound event %d\n", n);
+						asm ("lock; and %1,%0":"=m"(hyp_shared_info.evtchn_pending[i]):"r"(~(1UL<<j)));
+					}
+				}
+			}
+		}
+	}
+}
+
+void form_int_mask(void)
+{
+	unsigned int j, bit, mask;
+	int i;
+
+	for (i=SPL0; i < NSPL; i++) {
+		for (j=0x00, bit=0x01, mask = 0; j < NEVNT; j++, bit<<=1)
+			if (intpri[j] <= i)
+				mask |= bit;
+		int_mask[i] = mask;
+	}
+}
+
+extern void hyp_callback(void);
+extern void hyp_failsafe_callback(void);
+
+void hyp_intrinit(void) {
+	int i;
+
+	form_int_mask();
+	for (i = 0; i < NCPUS; i++)
+		curr_ipl[i] = SPLHI;
+	hyp_shared_info.evtchn_mask[0] = int_mask[SPLHI];
+#ifdef __i386__
+	hyp_set_callbacks(KERNEL_CS, hyp_callback,
+			  KERNEL_CS, hyp_failsafe_callback);
+#endif
+#ifdef __x86_64__
+	hyp_set_callbacks(hyp_callback, hyp_failsafe_callback, NULL);
+#endif
+}
+
+void hyp_evt_handler(evtchn_port_t port, interrupt_handler_fn handler, int unit, spl_t spl) {
+	if (port > NEVNT)
+		panic("event channel port %d > %d not supported\n", port, (int) NEVNT);
+	intpri[port] = spl;
+	iunit[port] = unit;
+	form_int_mask();
+	wmb();
+	ivect[port] = handler;
+}
-- 
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