[IA64] pvops: add an early setup hook for pv_ops.

This patch adds a setup hook in the very early boot sequence
before start_kernel() to initialize paravirtualization stuff.
The hook will be set by each pv loader code or by using multi entry point.

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, 41 insertions, 0 deletions

diff --git a/arch/ia64/kernel/head.S b/arch/ia64/kernel/head.S
index ddeab4e36fd..db540e58c78 100644
--- a/arch/ia64/kernel/head.S
+++ b/arch/ia64/kernel/head.S
@@ -26,11 +26,14 @@
 #include <asm/mmu_context.h>
 #include <asm/asm-offsets.h>
 #include <asm/pal.h>
+#include <asm/paravirt.h>
 #include <asm/pgtable.h>
 #include <asm/processor.h>
 #include <asm/ptrace.h>
 #include <asm/system.h>
 #include <asm/mca_asm.h>
+#include <linux/init.h>
+#include <linux/linkage.h>
 
 #ifdef CONFIG_HOTPLUG_CPU
 #define SAL_PSR_BITS_TO_SET                             \
@@ -367,6 +370,44 @@ start_ap:
         ;;
 (isBP)  st8 [r2]=r28            // save the address of the boot param area passed by the bootloader
 
+#ifdef CONFIG_PARAVIRT
+
+        movl r14=hypervisor_setup_hooks
+        movl r15=hypervisor_type
+        mov r16=num_hypervisor_hooks
+        ;;
+        ld8 r2=[r15]
+        ;;
+        cmp.ltu p7,p0=r2,r16    // array size check
+        shladd r8=r2,3,r14
+        ;;
+(p7)    ld8 r9=[r8]
+        ;;
+(p7)    mov b1=r9
+(p7)    cmp.ne.unc p7,p0=r9,r0  // no actual branch to NULL
+        ;;
+(p7)    br.call.sptk.many rp=b1
+
+        __INITDATA
+
+default_setup_hook = 0          // Currently nothing needs to be done.
+
+        .weak xen_setup_hook
+
+        .global hypervisor_type
+hypervisor_type:
+        data8           PARAVIRT_HYPERVISOR_TYPE_DEFAULT
+
+        // must have the same order with PARAVIRT_HYPERVISOR_TYPE_xxx
+
+hypervisor_setup_hooks:
+        data8           default_setup_hook
+        data8           xen_setup_hook
+num_hypervisor_hooks = (. - hypervisor_setup_hooks) / 8
+        .previous
+
+#endif
+
 #ifdef CONFIG_SMP
 (isAP)  br.call.sptk.many rp=start_secondary
 .ret0: