Pass the CPU index as a parameter to startup.

This addition is in support of future multicore support in
coreboot. It also will allow us to remove some asssembly code.

The CPU "index" -- i.e., its order in the sequence in which
cores are brought up, NOT its APIC id -- is passed into the
secondary start. We modify the function to specify regparm(0).
We also take this opportunity to do some cleanup:
indexes become unsigned ints, not unsigned longs, for example.

Build and boot on a multicore system, with pcserial enabled.

Capture the output. Observe that the messages
Initializing CPU #0
Initializing CPU #1
Initializing CPU #2
Initializing CPU #3
appear exactly as they do prior to this change.

Change-Id: I5854d8d957c414f75fdd63fb017d2249330f955d
Signed-off-by: Ronald G. Minnich <rminnich@chromium.org>
Reviewed-on: http://review.coreboot.org/1820
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)

2 files changed, 12 insertions, 8 deletions

diff --git a/src/cpu/x86/lapic/lapic_cpu_init.c b/src/cpu/x86/lapic/lapic_cpu_init.c
index 256066f309..9dbc80b829 100644
--- a/src/cpu/x86/lapic/lapic_cpu_init.c
+++ b/src/cpu/x86/lapic/lapic_cpu_init.c
@@ -209,13 +209,14 @@ static atomic_t active_cpus = ATOMIC_INIT(1);
  * for select the stack from assembly language.
  *
  * In addition communicating by variables to the cpu I
- * am starting allows me to veryify it has started before
+ * am starting allows me to verify it has started before
  * start_cpu returns.
  */
 
 static spinlock_t start_cpu_lock = SPIN_LOCK_UNLOCKED;
-static unsigned last_cpu_index = 0;
+static unsigned int last_cpu_index = 0;
 volatile unsigned long secondary_stack;
+volatile unsigned int secondary_cpu_index;
 void *stacks[CONFIG_MAX_CPUS];
 
 int start_cpu(device_t cpu)
@@ -226,7 +227,7 @@ int start_cpu(device_t cpu)
 	unsigned long stack_base;
 	unsigned long *stack;
 	unsigned long apicid;
-	unsigned long index;
+	unsigned int index;
 	unsigned long count;
 	int i;
 	int result;
@@ -243,7 +244,7 @@ int start_cpu(device_t cpu)
 	stack_end = ((unsigned long)_estack) - (CONFIG_STACK_SIZE*index) - sizeof(struct cpu_info);
 
 	stack_base = ((unsigned long)_estack) - (CONFIG_STACK_SIZE*(index+1));
-	printk(BIOS_SPEW, "CPU%ld: stack_base %p, stack_end %p\n", index,
+	printk(BIOS_SPEW, "CPU%d: stack_base %p, stack_end %p\n", index,
 		(void *)stack_base, (void *)stack_end);
 	/* poison the stack */
 	for(stack = (void *)stack_base, i = 0; i < CONFIG_STACK_SIZE; i++)
@@ -254,8 +255,9 @@ int start_cpu(device_t cpu)
 	info->index = index;
 	info->cpu   = cpu;
 
-	/* Advertise the new stack to start_cpu */
+	/* Advertise the new stack and index to start_cpu */
 	secondary_stack = stack_end;
+	secondary_cpu_index = index;
 
 	/* Until the cpu starts up report the cpu is not enabled */
 	cpu->enabled = 0;
@@ -384,7 +386,7 @@ static __inline__ __attribute__((always_inline)) void writecr4(unsigned long Dat
 #endif
 
 /* C entry point of secondary cpus */
-void __attribute__((regparm(0))) secondary_cpu_init(void)
+void __attribute__((regparm(0))) secondary_cpu_init(unsigned int index)
 {
 	atomic_inc(&active_cpus);
 #if CONFIG_SERIAL_CPU_INIT
@@ -401,7 +403,7 @@ void __attribute__((regparm(0))) secondary_cpu_init(void)
 	cr4_val |= (1 << 9 | 1 << 10);
 	writecr4(cr4_val);
 #endif
-	cpu_initialize();
+	cpu_initialize(index);
 #if CONFIG_SERIAL_CPU_INIT
 	spin_unlock(&start_cpu_lock);
 #endif
@@ -537,7 +539,7 @@ void initialize_cpus(struct bus *cpu_bus)
 #endif
 
 	/* Initialize the bootstrap processor */
-	cpu_initialize();
+	cpu_initialize(0);
 
 #if CONFIG_SMP && CONFIG_MAX_CPUS > 1
 	#if CONFIG_SERIAL_CPU_INIT
diff --git a/src/cpu/x86/lapic/secondary.S b/src/cpu/x86/lapic/secondary.S
index ec1bd9c4d4..045454e2ed 100644
--- a/src/cpu/x86/lapic/secondary.S
+++ b/src/cpu/x86/lapic/secondary.S
@@ -53,6 +53,8 @@ __ap_protected_start:
 	/* Set the stack pointer, and flag that we are done */
 	xorl	%eax, %eax
 	movl	secondary_stack, %esp
+	movl	secondary_cpu_index, %edi
+	pushl	%edi
 	movl	%eax, secondary_stack
 
 	call	secondary_cpu_init