x86, realmode: Separate real_mode reserve and setup

After we switch to use #PF handler help to set page table, init_level4_pgt
will only have entries set after init_mem_mapping().
We need to move copying init_level4_pgt to trampoline_pgd after that.

So split reserve and setup, and move the setup after init_mem_mapping()

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-11-git-send-email-yinghai@kernel.org
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 20 insertions, 12 deletions

diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index ffee06ac7de9..4b5bdc8c8710 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -8,9 +8,26 @@
 struct real_mode_header *real_mode_header;
 u32 *trampoline_cr4_features;
 
-void __init setup_real_mode(void)
+void __init reserve_real_mode(void)
 {
         phys_addr_t mem;
+        unsigned char *base;
+        size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
+
+        /* Has to be under 1M so we can execute real-mode AP code. */
+        mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
+        if (!mem)
+                panic("Cannot allocate trampoline\n");
+
+        base = __va(mem);
+        memblock_reserve(mem, size);
+        real_mode_header = (struct real_mode_header *) base;
+        printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
+               base, (unsigned long long)mem, size);
+}
+
+void __init setup_real_mode(void)
+{
         u16 real_mode_seg;
         u32 *rel;
         u32 count;
@@ -25,16 +42,7 @@ void __init setup_real_mode(void)
         u64 efer;
 #endif
 
-        /* Has to be in very low memory so we can execute real-mode AP code. */
-        mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
-        if (!mem)
-                panic("Cannot allocate trampoline\n");
-
-        base = __va(mem);
-        memblock_reserve(mem, size);
-        real_mode_header = (struct real_mode_header *) base;
-        printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
-               base, (unsigned long long)mem, size);
+        base = (unsigned char *)real_mode_header;
 
         memcpy(base, real_mode_blob, size);
 
@@ -84,7 +92,7 @@ void __init setup_real_mode(void)
 }
 
 /*
- * setup_real_mode() gets called very early, to guarantee the
+ * reserve_real_mode() gets called very early, to guarantee the
  * availability of low memory. This is before the proper kernel page
  * tables are set up, so we cannot set page permissions in that
  * function. Also trampoline code will be executed by APs so we