ia64/pv_ops/xen: elf note based xen startup.

This patch enables elf note based xen startup for IA-64, which gives the
kernel an early hint for running on xen like x86 case.
In order to avoid the multi entry point, presumably extending booting
protocol(i.e. extending struct ia64_boot_param) would be necessary.
It probably means that elilo also needs modification.

Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/arch/ia64/xen/xen_pv_ops.c b/arch/ia64/xen/xen_pv_ops.c
new file mode 100644
index 00000000000..77db214b116
--- /dev/null
+++ b/arch/ia64/xen/xen_pv_ops.c
@@ -0,0 +1,65 @@
+/******************************************************************************
+ * arch/ia64/xen/xen_pv_ops.c
+ *
+ * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
+ *                    VA Linux Systems Japan K.K.
+ *
+ * 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 <linux/console.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/pm.h>
+
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/xencomm.h>
+#include <asm/xen/privop.h>
+
+/***************************************************************************
+ * general info
+ */
+static struct pv_info xen_info __initdata = {
+	.kernel_rpl = 2,	/* or 1: determin at runtime */
+	.paravirt_enabled = 1,
+	.name = "Xen/ia64",
+};
+
+#define IA64_RSC_PL_SHIFT	2
+#define IA64_RSC_PL_BIT_SIZE	2
+#define IA64_RSC_PL_MASK	\
+	(((1UL << IA64_RSC_PL_BIT_SIZE) - 1) << IA64_RSC_PL_SHIFT)
+
+static void __init
+xen_info_init(void)
+{
+	/* Xenified Linux/ia64 may run on pl = 1 or 2.
+	 * determin at run time. */
+	unsigned long rsc = ia64_getreg(_IA64_REG_AR_RSC);
+	unsigned int rpl = (rsc & IA64_RSC_PL_MASK) >> IA64_RSC_PL_SHIFT;
+	xen_info.kernel_rpl = rpl;
+}
+
+/***************************************************************************
+ * pv_ops initialization
+ */
+
+void __init
+xen_setup_pv_ops(void)
+{
+	xen_info_init();
+	pv_info = xen_info;
+}