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>

3 files changed, 150 insertions, 1 deletions

diff --git a/arch/ia64/xen/Makefile b/arch/ia64/xen/Makefile
index eb595637a8ca..abc356f0c5da 100644
--- a/arch/ia64/xen/Makefile
+++ b/arch/ia64/xen/Makefile
@@ -2,4 +2,5 @@
 # Makefile for Xen components
 #
 
-obj-y := hypercall.o xencomm.o xcom_hcall.o grant-table.o
+obj-y := hypercall.o xensetup.o xen_pv_ops.o \
+        xencomm.o xcom_hcall.o grant-table.o
diff --git a/arch/ia64/xen/xen_pv_ops.c b/arch/ia64/xen/xen_pv_ops.c
new file mode 100644
index 000000000000..77db214b116c
--- /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;
+}
diff --git a/arch/ia64/xen/xensetup.S b/arch/ia64/xen/xensetup.S
new file mode 100644
index 000000000000..28fed1fcc079
--- /dev/null
+++ b/arch/ia64/xen/xensetup.S
@@ -0,0 +1,83 @@
+/*
+ * Support routines for Xen
+ *
+ * Copyright (C) 2005 Dan Magenheimer <dan.magenheimer@hp.com>
+ */
+
+#include <asm/processor.h>
+#include <asm/asmmacro.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/paravirt.h>
+#include <asm/xen/privop.h>
+#include <linux/elfnote.h>
+#include <linux/init.h>
+#include <xen/interface/elfnote.h>
+
+        .section .data.read_mostly
+        .align 8
+        .global xen_domain_type
+xen_domain_type:
+        data4 XEN_NATIVE_ASM
+        .previous
+
+        __INIT
+ENTRY(startup_xen)
+        // Calculate load offset.
+        // The constant, LOAD_OFFSET, can't be used because the boot
+        // loader doesn't always load to the LMA specified by the vmlinux.lds.
+        mov r9=ip       // must be the first instruction to make sure
+                        // that r9 = the physical address of startup_xen.
+                        // Usually r9 = startup_xen - LOAD_OFFSET
+        movl r8=startup_xen
+        ;;
+        sub r9=r9,r8    // Usually r9 = -LOAD_OFFSET.
+
+        mov r10=PARAVIRT_HYPERVISOR_TYPE_XEN
+        movl r11=_start
+        ;;
+        add r11=r11,r9
+        movl r8=hypervisor_type
+        ;;
+        add r8=r8,r9
+        mov b0=r11
+        ;;
+        st8 [r8]=r10
+        br.cond.sptk.many b0
+        ;;
+END(startup_xen)
+
+        ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS,      .asciz "linux")
+        ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION, .asciz "2.6")
+        ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION,   .asciz "xen-3.0")
+        ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,         data8.ua startup_xen - LOAD_OFFSET)
+
+#define isBP    p3      // are we the Bootstrap Processor?
+
+        .text
+
+GLOBAL_ENTRY(xen_setup_hook)
+        mov r8=XEN_PV_DOMAIN_ASM
+(isBP)  movl r9=xen_domain_type;;
+(isBP)  st4 [r9]=r8
+        movl r10=xen_ivt;;
+
+        mov cr.iva=r10
+
+        /* Set xsi base.  */
+#define FW_HYPERCALL_SET_SHARED_INFO_VA                 0x600
+(isBP)  mov r2=FW_HYPERCALL_SET_SHARED_INFO_VA
+(isBP)  movl r28=XSI_BASE;;
+(isBP)  break 0x1000;;
+
+        /* setup pv_ops */
+(isBP)  mov r4=rp
+        ;;
+(isBP)  br.call.sptk.many rp=xen_setup_pv_ops
+        ;;
+(isBP)  mov rp=r4
+        ;;
+
+        br.ret.sptk.many rp
+        ;;
+END(xen_setup_hook)