From 85cca7096fcf6a4d47c906b4ce73b094638643a7 Mon Sep 17 00:00:00 2001
From: Tomas Hruby <tom@minix3.org>
Date: Wed, 15 Sep 2010 14:10:07 +0000
Subject: [PATCH] SMP - The slave CPUs turn paging on

- APs wait until BSP turns paging on, it is not possible to safely
  execute any code on APs until we can turn paging on as well as it
  must be done synchronously everywhere

- APs turn paging on but do not continue and wait
---
 kernel/arch/i386/apic.c               | 2 +-
 kernel/arch/i386/arch_smp.c           | 6 ++++++
 kernel/arch/i386/include/arch_proto.h | 1 +
 kernel/main.c                         | 8 +++++++-
 4 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/kernel/arch/i386/apic.c b/kernel/arch/i386/apic.c
index 8bc855b2a..ed6f48e03 100644
--- a/kernel/arch/i386/apic.c
+++ b/kernel/arch/i386/apic.c
@@ -835,7 +835,7 @@ PUBLIC void apic_idt_init(const int reset)
 	}
 
 #ifdef CONFIG_APIC_DEBUG
-	if (cpu_is_bsp(cpuid))
+	if (is_bsp)
 		printf("APIC debugging is enabled\n");
 	lapic_set_dummy_handlers();
 #endif
diff --git a/kernel/arch/i386/arch_smp.c b/kernel/arch/i386/arch_smp.c
index ce6009aaa..b10abbaa9 100644
--- a/kernel/arch/i386/arch_smp.c
+++ b/kernel/arch/i386/arch_smp.c
@@ -190,6 +190,12 @@ PRIVATE void ap_finish_booting(void)
 	while(!i386_paging_enabled)
 		arch_pause();
 
+	/*
+	 * we must load some page tables befre we turn paging on. As VM is
+	 * always present we use those
+	 */
+	segmentation2paging(proc_addr(VM_PROC_NR));
+
 	BKL_LOCK();
 	printf("CPU %d is running\n", cpu);
 	BKL_UNLOCK();
diff --git a/kernel/arch/i386/include/arch_proto.h b/kernel/arch/i386/include/arch_proto.h
index 54658754c..189d879ce 100644
--- a/kernel/arch/i386/include/arch_proto.h
+++ b/kernel/arch/i386/include/arch_proto.h
@@ -54,6 +54,7 @@ _PROTOTYPE( void kernel_call_entry, (void) );
 _PROTOTYPE( void level0_call, (void) );
 
 /* memory.c */
+_PROTOTYPE( void segmentation2paging, (struct proc * current));
 _PROTOTYPE( void i386_freepde, (int pde));
 _PROTOTYPE( void getcr3val, (void));
 
diff --git a/kernel/main.c b/kernel/main.c
index a870e4466..043926341 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -285,8 +285,14 @@ PUBLIC int main(void)
   } else if (config_no_smp) {
 	  BOOT_VERBOSE(printf("SMP disabled, using legacy PIC\n"));
 	  smp_single_cpu_fallback();
-  } else
+  } else {
 	  smp_init();
+	  /*
+	   * if smp_init() returns it means that it failed and we try to finish
+	   * single CPU booting
+	   */
+	  bsp_finish_booting();
+  }
 #else
   /* 
    * if configured for a single CPU, we are already on the kernel stack which we
-- 
2.44.0