x86: prepare 64-bit architecture initialization for paravirt

[firefly-linux-kernel-4.4.55.git] / arch / x86 / kernel / setup_64.c

diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index f2b131ef844e085cb8ff1a97f71b7a374948395f..8dd110d93e7391a3e23fbd4ae14b3c1e01d994b8 100644 (file)
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -39,6 +39,7 @@
 #include <linux/dmi.h>
 #include <linux/dma-mapping.h>
 #include <linux/ctype.h>
+#include <linux/uaccess.h>
 
 #include <asm/mtrr.h>
 #include <asm/uaccess.h>
@@ -62,6 +63,12 @@
 #include <asm/mce.h>
 #include <asm/ds.h>
 
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
+#define ARCH_SETUP
+#endif
+
 /*
  * Machine setup..
  */
@@ -246,6 +253,16 @@ static void discover_ebda(void)
         * 4K EBDA area at 0x40E
         */
        ebda_addr = *(unsigned short *)__va(EBDA_ADDR_POINTER);
+       /*
+        * There can be some situations, like paravirtualized guests,
+        * in which there is no available ebda information. In such
+        * case, just skip it
+        */
+       if (!ebda_addr) {
+               ebda_size = 0;
+               return;
+       }
+
        ebda_addr <<= 4;
 
        ebda_size = *(unsigned short *)__va(ebda_addr);
@@ -259,6 +276,12 @@ static void discover_ebda(void)
                ebda_size = 64*1024;
 }
 
+/* Overridden in paravirt.c if CONFIG_PARAVIRT */
+void __attribute__((weak)) memory_setup(void)
+{
+       machine_specific_memory_setup();
+}
+
 void __init setup_arch(char **cmdline_p)
 {
        unsigned i;
@@ -276,7 +299,10 @@ void __init setup_arch(char **cmdline_p)
        rd_prompt = ((boot_params.hdr.ram_size & RAMDISK_PROMPT_FLAG) != 0);
        rd_doload = ((boot_params.hdr.ram_size & RAMDISK_LOAD_FLAG) != 0);
 #endif
-       setup_memory_region();
+
+       ARCH_SETUP
+
+       memory_setup();
        copy_edd();
 
        if (!boot_params.hdr.root_flags)