Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / ipxe / src / interface / linux / linux_timer.c

diff --git a/qemu/roms/ipxe/src/interface/linux/linux_timer.c b/qemu/roms/ipxe/src/interface/linux/linux_timer.c
new file mode 100644 (file)
index 0000000..7a99451
--- /dev/null
+++ b/qemu/roms/ipxe/src/interface/linux/linux_timer.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2010 Piotr Jaroszyński <p.jaroszynski@gmail.com>
+ *
+ * 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 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+FILE_LICENCE(GPL2_OR_LATER);
+
+#include <stddef.h>
+#include <ipxe/timer.h>
+
+#include <linux_api.h>
+
+/** @file
+ *
+ * iPXE timer API for linux
+ *
+ */
+
+/**
+ * Delay for a fixed number of microseconds
+ *
+ * @v usecs            Number of microseconds for which to delay
+ */
+static void linux_udelay(unsigned long usecs)
+{
+       linux_usleep(usecs);
+}
+
+/**
+ * Get number of ticks per second
+ *
+ * @ret ticks_per_sec  Number of ticks per second
+ */
+static unsigned long linux_ticks_per_sec(void)
+{
+       return 1000;
+}
+
+/**
+ * Get current system time in ticks
+ *
+ * linux doesn't provide an easy access to jiffies so implement it by measuring
+ * the time since the first call to this function.
+ *
+ * Since this function is used to seed the (non-cryptographic) random
+ * number generator, we round the start time down to the nearest whole
+ * second.  This minimises the chances of generating identical RNG
+ * sequences (and hence identical TCP port numbers, etc) on
+ * consecutive invocations of iPXE.
+ *
+ * @ret ticks          Current time, in ticks
+ */
+static unsigned long linux_currticks(void)
+{
+       static struct timeval start;
+       static int initialized = 0;
+
+       if (! initialized) {
+               linux_gettimeofday(&start, NULL);
+               initialized = 1;
+       }
+
+       struct timeval now;
+       linux_gettimeofday(&now, NULL);
+
+       unsigned long ticks = (now.tv_sec - start.tv_sec) * linux_ticks_per_sec();
+       ticks += now.tv_usec / (long)(1000000 / linux_ticks_per_sec());
+
+       return ticks;
+}
+
+PROVIDE_TIMER(linux, udelay, linux_udelay);
+PROVIDE_TIMER(linux, currticks, linux_currticks);
+PROVIDE_TIMER(linux, ticks_per_sec, linux_ticks_per_sec);