x86 Fix VMI crash on boot in 2.6.28-rc8

VMI initialiation can relocate the fixmap, causing early_ioremap to
malfunction if it is initialized before the relocation.  To fix this,
VMI activation is split into two phases; the detection, which must
happen before setting up ioremap, and the activation, which must happen
after parsing early boot parameters.

This fixes a crash on boot when VMI is enabled under VMware.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 23 insertions, 15 deletions

diff --git a/arch/x86/include/asm/vmi.h b/arch/x86/include/asm/vmi.h
index b7c0dea119fe..61e08c0a2907 100644
--- a/arch/x86/include/asm/vmi.h
+++ b/arch/x86/include/asm/vmi.h
@@ -223,9 +223,15 @@ struct pci_header {
 } __attribute__((packed));
 
 /* Function prototypes for bootstrapping */
+#ifdef CONFIG_VMI
 extern void vmi_init(void);
+extern void vmi_activate(void);
 extern void vmi_bringup(void);
-extern void vmi_apply_boot_page_allocations(void);
+#else
+static inline void vmi_init(void) {}
+static inline void vmi_activate(void) {}
+static inline void vmi_bringup(void) {}
+#endif
 
 /* State needed to start an application processor in an SMP system. */
 struct vmi_ap_state {
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 9d5674f7b6cc..bdec76e55594 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -794,6 +794,9 @@ void __init setup_arch(char **cmdline_p)
         printk(KERN_INFO "Command line: %s\n", boot_command_line);
 #endif
 
+        /* VMI may relocate the fixmap; do this before touching ioremap area */
+        vmi_init();
+
         early_cpu_init();
         early_ioremap_init();
 
@@ -880,13 +883,8 @@ void __init setup_arch(char **cmdline_p)
         check_efer();
 #endif
 
-#if defined(CONFIG_VMI) && defined(CONFIG_X86_32)
-        /*
-         * Must be before kernel pagetables are setup
-         * or fixmap area is touched.
-         */
-        vmi_init();
-#endif
+        /* Must be before kernel pagetables are setup */
+        vmi_activate();
 
         /* after early param, so could get panic from serial */
         reserve_early_setup_data();
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 7b1093397319..f71f96fc9e62 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -294,9 +294,7 @@ static void __cpuinit start_secondary(void *unused)
          * fragile that we want to limit the things done here to the
          * most necessary things.
          */
-#ifdef CONFIG_VMI
         vmi_bringup();
-#endif
         cpu_init();
         preempt_disable();
         smp_callin();
diff --git a/arch/x86/kernel/vmi_32.c b/arch/x86/kernel/vmi_32.c
index 8b6c393ab9fd..22fd6577156a 100644
--- a/arch/x86/kernel/vmi_32.c
+++ b/arch/x86/kernel/vmi_32.c
@@ -960,8 +960,6 @@ static inline int __init activate_vmi(void)
 
 void __init vmi_init(void)
 {
-        unsigned long flags;
-
         if (!vmi_rom)
                 probe_vmi_rom();
         else
@@ -973,13 +971,21 @@ void __init vmi_init(void)
 
         reserve_top_address(-vmi_rom->virtual_top);
 
-        local_irq_save(flags);
-        activate_vmi();
-
 #ifdef CONFIG_X86_IO_APIC
         /* This is virtual hardware; timer routing is wired correctly */
         no_timer_check = 1;
 #endif
+}
+
+void vmi_activate(void)
+{
+        unsigned long flags;
+
+        if (!vmi_rom)
+                return;
+
+        local_irq_save(flags);
+        activate_vmi();
         local_irq_restore(flags & X86_EFLAGS_IF);
 }