cleanup/consolidate above 4G memory parsing (Alex Williamson)

Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Index: bochs/bios/rombios32.c
===================================================================
--- bochs.orig/bios/rombios32.c
+++ bochs/bios/rombios32.c
@@ -427,7 +427,7 @@ uint32_t cpuid_signature;
 uint32_t cpuid_features;
 uint32_t cpuid_ext_features;
 unsigned long ram_size;
-uint64_t above4g_ram_size;
+uint64_t ram_end;
 uint8_t bios_uuid[16];
 #ifdef BX_USE_EBDA_TABLES
 unsigned long ebda_cur_addr;
@@ -562,9 +562,9 @@ void setup_mtrr(void)
         wrmsr_smp(MTRRphysMask_MSR(i), (~vmask & 0xfffffff000ull) | 0x800);
         vbase += vmask + 1;
     }
-    for (vbase = 1ull << 32; i < vcnt && vbase < above4g_ram_size; ++i) {
+    for (vbase = 1ull << 32; i < vcnt && vbase < ram_end; ++i) {
         vmask = (1ull << 40) - 1;
-        while (vbase + vmask + 1 > above4g_ram_size)
+        while (vbase + vmask + 1 > ram_end)
             vmask >>= 1;
         wrmsr_smp(MTRRphysBase_MSR(i), vbase | 6);
         wrmsr_smp(MTRRphysMask_MSR(i), (~vmask & 0xfffffff000ull) | 0x800);
@@ -582,18 +582,19 @@ void ram_probe(void)
     ram_size = (cmos_readb(0x30) | (cmos_readb(0x31) << 8)) * 1024 +
         1 * 1024 * 1024;
   if (cmos_readb(0x5b) | cmos_readb(0x5c) | cmos_readb(0x5d))
-    above4g_ram_size = ((uint64_t)cmos_readb(0x5b) << 16) |
-        ((uint64_t)cmos_readb(0x5c) << 24) | ((uint64_t)cmos_readb(0x5d) << 32);
+    ram_end = (((uint64_t)cmos_readb(0x5b) << 16) |
+               ((uint64_t)cmos_readb(0x5c) << 24) |
+               ((uint64_t)cmos_readb(0x5d) << 32)) + (1ull << 32);
+  else
+    ram_end = ram_size;

-  if (above4g_ram_size)
-    above4g_ram_size += 1ull << 32;
+  BX_INFO("end of ram=%ldMB\n", ram_end >> 20);

   BX_INFO("ram_size=0x%08lx\n", ram_size);
 #ifdef BX_USE_EBDA_TABLES
   ebda_cur_addr = ((*(uint16_t *)(0x40e)) << 4) + 0x380;
   BX_INFO("ebda_cur_addr: 0x%08lx\n", ebda_cur_addr);
 #endif
-  BX_INFO("top of ram %ldMB\n", above4g_ram_size >> 20);
   setup_mtrr();
 }