x86: extend e820 early_res support 32bit -fix #3

introduce init_pg_table_start, so xen PV could specify the value.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

6 files changed, 19 insertions, 5 deletions

diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index c216d3c2a991..0b6cb9fba71e 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -76,7 +76,8 @@ void __init i386_start_kernel(void)
                 reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
         }
 #endif
-        reserve_early(__pa_symbol(&_end), init_pg_tables_end, "INIT_PG_TABLE");
+        reserve_early(init_pg_tables_start, init_pg_tables_end,
+                        "INIT_PG_TABLE");
 
         reserve_ebda_region();
 
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index b2cc73768a9d..bef4618feadb 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -194,6 +194,7 @@ default_entry:
         xorl %ebx,%ebx                          /* %ebx is kept at zero */
 
         movl $pa(pg0), %edi
+        movl %edi, pa(init_pg_tables_start)
         movl $pa(swapper_pg_pmd), %edx
         movl $PTE_ATTR, %eax
 10:
@@ -228,6 +229,7 @@ default_entry:
 page_pde_offset = (__PAGE_OFFSET >> 20);
 
         movl $pa(pg0), %edi
+        movl %edi, pa(init_pg_tables_start)
         movl $pa(swapper_pg_dir), %edx
         movl $PTE_ATTR, %eax
 10:
diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c
index 08b47a2f7af0..de9c5ee77d07 100644
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -71,6 +71,7 @@
 /* This value is set up by the early boot code to point to the value
    immediately after the boot time page tables.  It contains a *physical*
    address, and must not be in the .bss segment! */
+unsigned long init_pg_tables_start __initdata = ~0UL;
 unsigned long init_pg_tables_end __initdata = ~0UL;
 
 /*
@@ -485,6 +486,10 @@ static void __init reserve_initrd(void)
                 return;
         }
 
+        printk(KERN_INFO "old RAMDISK: %08llx - %08llx\n", ramdisk_image,
+                        ramdisk_end);
+
+
         if (ramdisk_end <= end_of_lowmem) {
                 /* All in lowmem, easy case */
                 /*
@@ -511,6 +516,8 @@ static void __init reserve_initrd(void)
                          "NEW RAMDISK");
         initrd_start = ramdisk_here + PAGE_OFFSET;
         initrd_end   = initrd_start + ramdisk_size;
+        printk(KERN_INFO "Allocated new RAMDISK: %08llx - %08llx\n",
+                         ramdisk_here, ramdisk_here + ramdisk_size);
 
         do_relocate_initrd = true;
 }
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index af65b2da3ba0..bf7c34a3aaeb 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -1011,6 +1011,7 @@ __init void lguest_init(void)
          * clobbered.  The Launcher places our initial pagetables somewhere at
          * the top of our physical memory, so we don't need extra space: set
          * init_pg_tables_end to the end of the kernel. */
+        init_pg_tables_start = __pa(pg0);
         init_pg_tables_end = __pa(pg0);
 
         /* Load the %fs segment register (the per-cpu segment register) with
@@ -1064,9 +1065,9 @@ __init void lguest_init(void)
         pm_power_off = lguest_power_off;
         machine_ops.restart = lguest_restart;
 
-        /* Now we're set up, call start_kernel() in init/main.c and we proceed
+        /* Now we're set up, call i386_start_kernel() in head32.c and we proceed
          * to boot as normal.  It never returns. */
-        start_kernel();
+        i386_start_kernel();
 }
 /*
  * This marks the end of stage II of our journey, The Guest.
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index c8a56e457d61..ccc7b84ddabf 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1211,6 +1211,7 @@ asmlinkage void __init xen_start_kernel(void)
 
         pgd = (pgd_t *)xen_start_info->pt_base;
 
+        init_pg_tables_start = __pa(pgd);
         init_pg_tables_end = __pa(pgd) + xen_start_info->nr_pt_frames*PAGE_SIZE;
 
         init_mm.pgd = pgd; /* use the Xen pagetables to start */
@@ -1246,5 +1247,5 @@ asmlinkage void __init xen_start_kernel(void)
                 add_preferred_console("hvc", 0, NULL);
 
         /* Start the world */
-        start_kernel();
+        i386_start_kernel();
 }
diff --git a/include/asm-x86/setup.h b/include/asm-x86/setup.h
index ffa0f540fc7f..64f5f0c11d66 100644
--- a/include/asm-x86/setup.h
+++ b/include/asm-x86/setup.h
@@ -59,9 +59,11 @@ int __init copy_e820_map(struct e820entry *biosmap, int nr_map);
 void __init add_memory_region(unsigned long long start,
                               unsigned long long size, int type);
 
-extern unsigned long init_pg_tables_end;
 
+void __init i386_start_kernel(void);
 
+extern unsigned long init_pg_tables_start;
+extern unsigned long init_pg_tables_end;
 
 #endif /* __i386__ */
 #endif /* _SETUP */