x86_64: add workaround for no %gs-based percpu

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / head64.c

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index d31d6b72d60dd2229c7978300c19e4f83630b4de..1b318e903bf63f14bd4f514ad8fd5916289bb979 100644 (file)
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -11,6 +11,7 @@
 #include <linux/string.h>
 #include <linux/percpu.h>
 #include <linux/start_kernel.h>
+#include <linux/io.h>
 
 #include <asm/processor.h>
 #include <asm/proto.h>
@@ -24,6 +25,27 @@
 #include <asm/e820.h>
 #include <asm/bios_ebda.h>
 
+/* boot cpu pda */
+static struct x8664_pda _boot_cpu_pda __read_mostly;
+
+#ifdef CONFIG_SMP
+/*
+ * We install an empty cpu_pda pointer table to indicate to early users
+ * (numa_set_node) that the cpu_pda pointer table for cpus other than
+ * the boot cpu is not yet setup.
+ */
+static struct x8664_pda *__cpu_pda[NR_CPUS] __initdata;
+#else
+static struct x8664_pda *__cpu_pda[NR_CPUS] __read_mostly;
+#endif
+
+void __init x86_64_init_pda(void)
+{
+       _cpu_pda = __cpu_pda;
+       cpu_pda(0) = &_boot_cpu_pda;
+       pda_init(0);
+}
+
 static void __init zap_identity_mappings(void)
 {
        pgd_t *pgd = pgd_offset_k(0UL);
@@ -50,56 +72,6 @@ static void __init copy_bootdata(char *real_mode_data)
        }
 }
 
-#define BIOS_LOWMEM_KILOBYTES 0x413
-
-/*
- * The BIOS places the EBDA/XBDA at the top of conventional
- * memory, and usually decreases the reported amount of
- * conventional memory (int 0x12) too. This also contains a
- * workaround for Dell systems that neglect to reserve EBDA.
- * The same workaround also avoids a problem with the AMD768MPX
- * chipset: reserve a page before VGA to prevent PCI prefetch
- * into it (errata #56). Usually the page is reserved anyways,
- * unless you have no PS/2 mouse plugged in.
- */
-static void __init reserve_ebda_region(void)
-{
-       unsigned int lowmem, ebda_addr;
-
-       /* To determine the position of the EBDA and the */
-       /* end of conventional memory, we need to look at */
-       /* the BIOS data area. In a paravirtual environment */
-       /* that area is absent. We'll just have to assume */
-       /* that the paravirt case can handle memory setup */
-       /* correctly, without our help. */
-       if (paravirt_enabled())
-               return;
-
-       /* end of low (conventional) memory */
-       lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES);
-       lowmem <<= 10;
-
-       /* start of EBDA area */
-       ebda_addr = get_bios_ebda();
-
-       /* Fixup: bios puts an EBDA in the top 64K segment */
-       /* of conventional memory, but does not adjust lowmem. */
-       if ((lowmem - ebda_addr) <= 0x10000)
-               lowmem = ebda_addr;
-
-       /* Fixup: bios does not report an EBDA at all. */
-       /* Some old Dells seem to need 4k anyhow (bugzilla 2990) */
-       if ((ebda_addr == 0) && (lowmem >= 0x9f000))
-               lowmem = 0x9f000;
-
-       /* Paranoia: should never happen, but... */
-       if ((lowmem == 0) || (lowmem >= 0x100000))
-               lowmem = 0x9f000;
-
-       /* reserve all memory between lowmem and the 1MB mark */
-       reserve_early(lowmem, 0x100000, "BIOS reserved");
-}
-
 void __init x86_64_start_kernel(char * real_mode_data)
 {
        int i;
@@ -137,10 +109,15 @@ void __init x86_64_start_kernel(char * real_mode_data)
 
        early_printk("Kernel alive\n");
 
-       for (i = 0; i < NR_CPUS; i++)
-               cpu_pda(i) = &boot_cpu_pda[i];
+       x86_64_init_pda();
 
-       pda_init(0);
+       early_printk("Kernel really alive\n");
+
+       x86_64_start_reservations(real_mode_data);
+}
+
+void __init x86_64_start_reservations(char *real_mode_data)
+{
        copy_bootdata(__va(real_mode_data));
 
        reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA BSS");