[PATCH] make gnttab.c can be used in para-driver for unmodified guest

[Xiaofeng Ling <xiaofeng.ling@intel.com>]

make gnttab.c can be used in para-driver for unmodified guest
changes are:
1. export one more symbols, include more files
2. A different implementation for setup grant table share page
    use ioremap to map the physical address returned by hypercall.
3. remove static for gnttab_init so that it can be called from
module init function in event channel pci driver.

Signed-off-by: Xiaofeng Ling <xiaofeng.ling@intel.com>
Signed-off-by: Arun Sharma <arun.sharma@intel.com>


diff -r 287d36b46fa3 linux-2.6-xen-sparse/arch/xen/kernel/gnttab.c
--- a/linux-2.6-xen-sparse/arch/xen/kernel/gnttab.c	Tue Aug 30 20:36:49 2005
+++ b/linux-2.6-xen-sparse/arch/xen/kernel/gnttab.c	Fri Sep  2 22:47:27 2005
@@ -17,9 +17,13 @@
  #include <asm/fixmap.h>
  #include <asm/uaccess.h>
  #include <asm-xen/xen_proc.h>
+#include <xen-public/xen.h>
  #include <asm-xen/linux-public/privcmd.h>
  #include <asm-xen/gnttab.h>
  #include <asm-xen/synch_bitops.h>
+#ifndef CONFIG_XEN
+#include <asm/io.h>
+#endif

  #if 1
  #define ASSERT(_p) \
@@ -47,6 +51,7 @@
  EXPORT_SYMBOL(gnttab_release_grant_reference);
  EXPORT_SYMBOL(gnttab_grant_foreign_access_ref);
  EXPORT_SYMBOL(gnttab_grant_foreign_transfer_ref);
+EXPORT_SYMBOL(gnttab_request_free_callback);

  #define NR_GRANT_ENTRIES (NR_GRANT_FRAMES * PAGE_SIZE / 
sizeof(grant_entry_t))
  #define GNTTAB_LIST_END (NR_GRANT_ENTRIES + 1)
@@ -404,9 +409,19 @@
  gnttab_resume(void)
  {
      gnttab_setup_table_t setup;
+#ifdef CONFIG_XEN
+    int                  i;
      unsigned long        frames[NR_GRANT_FRAMES];
-    int                  i;
-
+#else
+    unsigned long *frames;
+    unsigned long alloc_xen_mmio(unsigned long len);
+    frames = (unsigned long *)alloc_xen_mmio(PAGE_SIZE * NR_GRANT_FRAMES);
+    shared = ioremap((unsigned long)frames, PAGE_SIZE * NR_GRANT_FRAMES);
+    if(!shared){
+        printk("error to ioremap gnttab share frames\n");
+        return -1;
+    }
+#endif
      setup.dom        = DOMID_SELF;
      setup.nr_frames  = NR_GRANT_FRAMES;
      setup.frame_list = frames;
@@ -414,8 +429,10 @@
      BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1) 
!= 0);
      BUG_ON(setup.status != 0);

+#ifdef CONFIG_XEN
      for ( i = 0; i < NR_GRANT_FRAMES; i++ )
          set_fixmap(FIX_GNTTAB_END - i, frames[i] << PAGE_SHIFT);
+#endif

      return 0;
  }
@@ -423,22 +440,27 @@
  int
  gnttab_suspend(void)
  {
+#ifdef CONFIG_XEN
      int i;

      for ( i = 0; i < NR_GRANT_FRAMES; i++ )
  	clear_fixmap(FIX_GNTTAB_END - i);
-
+#else
+    iounmap(shared);
+#endif
      return 0;
  }

-static int __init
+int __init
  gnttab_init(void)
  {
      int i;

      BUG_ON(gnttab_resume());

+#ifdef CONFIG_XEN
      shared = (grant_entry_t *)fix_to_virt(FIX_GNTTAB_END);
+#endif

      for ( i = 0; i < NR_GRANT_ENTRIES; i++ )
          gnttab_list[i] = i + 1;