Use broadcast SIPI to startup siblings

The current code for initializing AP cpus has several shortcomings:

- it assumes APIC IDs are sequential
- it uses only the BSP for determining the AP count, which is bad if
  there's more than one physical CPU, and CPUs are of different type

Note that the new code call cpu->ops->init() in parallel, and therefore
some CPU code needs to be changed to address that. One example are old
Intel HT enabled CPUs which can't do microcode update in parallel.

Change-Id: Ic48a1ebab6a7c52aa76765f497268af09fa38c25
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Reviewed-on: http://review.coreboot.org/1139
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

2 files changed, 86 insertions, 303 deletions

diff --git a/src/cpu/x86/lapic/lapic_cpu_init.c b/src/cpu/x86/lapic/lapic_cpu_init.c
index e491d46af2..061d3d3c41 100644
--- a/src/cpu/x86/lapic/lapic_cpu_init.c
+++ b/src/cpu/x86/lapic/lapic_cpu_init.c
@@ -66,31 +66,28 @@ static void copy_secondary_start_to_1m_below(void)
 	printk(BIOS_DEBUG, "start_eip=0x%08lx, offset=0x%08lx, code_size=0x%08lx\n", start_eip, ((unsigned long)_secondary_start - start_eip), code_size);
 }
 
-static int lapic_start_cpu(unsigned long apicid)
+static struct bus *current_cpu_bus;
+
+static int lapic_start_cpus(struct bus *cpu_bus)
 {
 	int timeout;
 	unsigned long send_status, accept_status, start_eip;
-	int j, num_starts, maxlvt;
+	int maxlvt;
 
 	/*
 	 * Starting actual IPI sequence...
 	 */
 
-	printk(BIOS_SPEW, "Asserting INIT.\n");
-
-	/*
-	 * Turn INIT on target chip
-	 */
-	lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid));
+	current_cpu_bus = cpu_bus;
 
-	/*
-	 * Send IPI
-	 */
+	printk(BIOS_SPEW, "Asserting INIT.\n");
 
-	lapic_write_around(LAPIC_ICR, LAPIC_INT_LEVELTRIG | LAPIC_INT_ASSERT
-				| LAPIC_DM_INIT);
+	/* Send INIT SIPI to target chip */
+	lapic_write_around(LAPIC_ICR2, 0);
+	lapic_write_around(LAPIC_ICR, LAPIC_INT_ASSERT
+				| LAPIC_DM_INIT | LAPIC_DEST_ALLBUT);
 
-	printk(BIOS_SPEW, "Waiting for send to finish...\n");
+	printk(BIOS_DEBUG, "Waiting for send to finish...\n");
 	timeout = 0;
 	do {
 		printk(BIOS_SPEW, "+");
@@ -98,108 +95,67 @@ static int lapic_start_cpu(unsigned long apicid)
 		send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
 	} while (send_status && (timeout++ < 1000));
 	if (timeout >= 1000) {
-		printk(BIOS_ERR, "CPU %ld: First apic write timed out. Disabling\n",
-			 apicid);
+		printk(BIOS_DEBUG, "First apic write timed out. Disabling\n");
 		// too bad.
-		printk(BIOS_ERR, "ESR is 0x%lx\n", lapic_read(LAPIC_ESR));
+		printk(BIOS_DEBUG, "ESR is 0x%lx\n", lapic_read(LAPIC_ESR));
 		if (lapic_read(LAPIC_ESR)) {
-			printk(BIOS_ERR, "Try to reset ESR\n");
+			printk(BIOS_DEBUG, "Try to reset ESR\n");
 			lapic_write_around(LAPIC_ESR, 0);
-			printk(BIOS_ERR, "ESR is 0x%lx\n", lapic_read(LAPIC_ESR));
+			printk(BIOS_DEBUG, "ESR is 0x%lx\n", lapic_read(LAPIC_ESR));
 		}
 		return 0;
 	}
-#if !CONFIG_CPU_AMD_MODEL_10XXX && !CONFIG_CPU_INTEL_MODEL_206AX
-	mdelay(10);
-#endif
+	start_eip = get_valid_start_eip((unsigned long)_secondary_start);
+
+	maxlvt = 4;
+
+	printk(BIOS_SPEW, "Sending STARTUP.\n");
+	lapic_read_around(LAPIC_SPIV);
+	lapic_write(LAPIC_ESR, 0);
+	lapic_read(LAPIC_ESR);
+	printk(BIOS_SPEW, "After apic_write.\n");
 
-	printk(BIOS_SPEW, "Deasserting INIT.\n");
+	/*
+	 * STARTUP IPI
+	 */
 
 	/* Target chip */
-	lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid));
+	lapic_write_around(LAPIC_ICR2, 0);
 
-	/* Send IPI */
-	lapic_write_around(LAPIC_ICR, LAPIC_INT_LEVELTRIG | LAPIC_DM_INIT);
+	/* Boot on the stack */
+	/* Kick the second */
+	lapic_write_around(LAPIC_ICR, LAPIC_INT_ASSERT | LAPIC_DM_STARTUP | LAPIC_DEST_ALLBUT
+			   | (start_eip >> 12));
 
-	printk(BIOS_SPEW, "Waiting for send to finish...\n");
+	/*
+	 * Give the other CPU some time to accept the IPI.
+	 */
+	udelay(300);
+
+	printk(BIOS_DEBUG, "Startup point 1.\n");
+
+	printk(BIOS_DEBUG, "Waiting for send to finish...\n");
 	timeout = 0;
 	do {
-		printk(BIOS_SPEW, "+");
+		printk(BIOS_DEBUG, "+");
 		udelay(100);
 		send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
 	} while (send_status && (timeout++ < 1000));
-	if (timeout >= 1000) {
-		printk(BIOS_ERR, "CPU %ld: Second apic write timed out. Disabling\n",
-			 apicid);
-		// too bad.
-		return 0;
-	}
-
-	start_eip = get_valid_start_eip((unsigned long)_secondary_start);
-
-#if !CONFIG_CPU_AMD_MODEL_10XXX
-	num_starts = 2;
-#else
-	num_starts = 1;
-#endif
 
 	/*
-	 * Run STARTUP IPI loop.
+	 * Give the other CPU some time to accept the IPI.
 	 */
-	printk(BIOS_SPEW, "#startup loops: %d.\n", num_starts);
-
-	maxlvt = 4;
-
-	for (j = 1; j <= num_starts; j++) {
-		printk(BIOS_SPEW, "Sending STARTUP #%d to %lu.\n", j, apicid);
+	udelay(200);
+	/*
+	 * Due to the Pentium erratum 3AP.
+	 */
+	if (maxlvt > 3) {
 		lapic_read_around(LAPIC_SPIV);
 		lapic_write(LAPIC_ESR, 0);
-		lapic_read(LAPIC_ESR);
-		printk(BIOS_SPEW, "After apic_write.\n");
-
-		/*
-		 * STARTUP IPI
-		 */
-
-		/* Target chip */
-		lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid));
-
-		/* Boot on the stack */
-		/* Kick the second */
-		lapic_write_around(LAPIC_ICR, LAPIC_DM_STARTUP
-					| (start_eip >> 12));
-
-		/*
-		 * Give the other CPU some time to accept the IPI.
-		 */
-		udelay(300);
-
-		printk(BIOS_SPEW, "Startup point 1.\n");
-
-		printk(BIOS_SPEW, "Waiting for send to finish...\n");
-		timeout = 0;
-		do {
-			printk(BIOS_SPEW, "+");
-			udelay(100);
-			send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
-		} while (send_status && (timeout++ < 1000));
-
-		/*
-		 * Give the other CPU some time to accept the IPI.
-		 */
-		udelay(200);
-		/*
-		 * Due to the Pentium erratum 3AP.
-		 */
-		if (maxlvt > 3) {
-			lapic_read_around(LAPIC_SPIV);
-			lapic_write(LAPIC_ESR, 0);
-		}
-		accept_status = (lapic_read(LAPIC_ESR) & 0xEF);
-		if (send_status || accept_status)
-			break;
 	}
-	printk(BIOS_SPEW, "After Startup.\n");
+	accept_status = (lapic_read(LAPIC_ESR) & 0xEF);
+
+	printk(BIOS_DEBUG, "After Startup.\n");
 	if (send_status)
 		printk(BIOS_WARNING, "APIC never delivered???\n");
 	if (accept_status)
@@ -209,156 +165,34 @@ static int lapic_start_cpu(unsigned long apicid)
 	return 1;
 }
 
+
 /* Number of cpus that are currently running in coreboot */
 static atomic_t active_cpus = ATOMIC_INIT(1);
 
-/* start_cpu_lock covers last_cpu_index and secondary_stack.
- * Only starting one cpu at a time let's me remove the logic
- * 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
- * start_cpu returns.
- */
-
-static spinlock_t start_cpu_lock = SPIN_LOCK_UNLOCKED;
-static unsigned last_cpu_index = 0;
 volatile unsigned long secondary_stack;
+extern unsigned char _estack[];
 
-int start_cpu(device_t cpu)
+static void stop_all_ap_cpus(void)
 {
-	extern unsigned char _estack[];
-	struct cpu_info *info;
-	unsigned long stack_end;
-	unsigned long apicid;
-	unsigned long index;
-	unsigned long count;
-	int result;
-
-	spin_lock(&start_cpu_lock);
-
-	/* Get the cpu's apicid */
-	apicid = cpu->path.apic.apic_id;
-
-	/* Get an index for the new processor */
-	index = ++last_cpu_index;
-
-	/* Find end of the new processors stack */
-	stack_end = ((unsigned long)_estack) - (CONFIG_STACK_SIZE*index) - sizeof(struct cpu_info);
-
-	/* Record the index and which cpu structure we are using */
-	info = (struct cpu_info *)stack_end;
-	info->index = index;
-	info->cpu   = cpu;
-
-	/* Advertise the new stack to start_cpu */
-	secondary_stack = stack_end;
-
-	/* Until the cpu starts up report the cpu is not enabled */
-	cpu->enabled = 0;
-	cpu->initialized = 0;
-
-	/* Start the cpu */
-	result = lapic_start_cpu(apicid);
-
-	if (result) {
-		result = 0;
-		/* Wait 1s or until the new cpu calls in */
-		for(count = 0; count < 100000 ; count++) {
-			if (secondary_stack == 0) {
-				result = 1;
-				break;
-			}
-			udelay(10);
-	}
-	}
-	secondary_stack = 0;
-	spin_unlock(&start_cpu_lock);
-	return result;
-}
-
-#if CONFIG_AP_IN_SIPI_WAIT
-
-/**
- * Sending INIT IPI to self is equivalent of asserting #INIT with a bit of delay.
- * An undefined number of instruction cycles will complete. All global locks
- * must be released before INIT IPI and no printk is allowed after this.
- * De-asserting INIT IPI is a no-op on later Intel CPUs.
- *
- * If you set DEBUG_HALT_SELF to 1, printk's after INIT IPI are enabled
- * but running thread may halt without releasing the lock and effectively
- * deadlock other CPUs.
- */
-#define DEBUG_HALT_SELF 0
-
-/**
- * Normally this function is defined in lapic.h as an always inline function
- * that just keeps the CPU in a hlt() loop. This does not work on all CPUs.
- * I think all hyperthreading CPUs might need this version, but I could only
- * verify this on the Intel Core Duo
- */
-void stop_this_cpu(void)
-{
-	int timeout;
 	unsigned long send_status;
-	unsigned long id;
-
-	id = lapic_read(LAPIC_ID) >> 24;
-
-	printk(BIOS_DEBUG, "CPU %ld going down...\n", id);
-
-	/* send an LAPIC INIT to myself */
-	lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(id));
-	lapic_write_around(LAPIC_ICR, LAPIC_INT_LEVELTRIG | LAPIC_INT_ASSERT | LAPIC_DM_INIT);
+	int timeout;
+	/* send an LAPIC INIT to all but myself */
+	lapic_write_around(LAPIC_ICR2, 0);
+	lapic_write_around(LAPIC_ICR, LAPIC_INT_ASSERT | LAPIC_DM_INIT | LAPIC_DEST_ALLBUT);
 
 	/* wait for the ipi send to finish */
-#if DEBUG_HALT_SELF
 	printk(BIOS_SPEW, "Waiting for send to finish...\n");
-#endif
 	timeout = 0;
 	do {
-#if DEBUG_HALT_SELF
 		printk(BIOS_SPEW, "+");
-#endif
 		udelay(100);
 		send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
 	} while (send_status && (timeout++ < 1000));
 	if (timeout >= 1000) {
-#if DEBUG_HALT_SELF
 		printk(BIOS_ERR, "timed out\n");
-#endif
 	}
 	mdelay(10);
-
-#if DEBUG_HALT_SELF
-	printk(BIOS_SPEW, "Deasserting INIT.\n");
-#endif
-	/* Deassert the LAPIC INIT */
-	lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(id));
-	lapic_write_around(LAPIC_ICR, LAPIC_INT_LEVELTRIG | LAPIC_DM_INIT);
-
-#if DEBUG_HALT_SELF
-	printk(BIOS_SPEW, "Waiting for send to finish...\n");
-#endif
-	timeout = 0;
-	do {
-#if DEBUG_HALT_SELF
-		printk(BIOS_SPEW, "+");
-#endif
-		udelay(100);
-		send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
-	} while (send_status && (timeout++ < 1000));
-	if (timeout >= 1000) {
-#if DEBUG_HALT_SELF
-		printk(BIOS_ERR, "timed out\n");
-#endif
-	}
-
-	while(1) {
-		hlt();
-	}
 }
-#endif
 
 #ifdef __SSE3__
 static __inline__ __attribute__((always_inline)) unsigned long readcr4(void)
@@ -381,66 +215,21 @@ static __inline__ __attribute__((always_inline)) void writecr4(unsigned long Dat
 #endif
 
 /* C entry point of secondary cpus */
-void secondary_cpu_init(void)
+void secondary_cpu_init(int index)
 {
-	atomic_inc(&active_cpus);
-#if CONFIG_SERIAL_CPU_INIT
-	spin_lock(&start_cpu_lock);
-#endif
-
 #ifdef __SSE3__
-	/*
-	 * Seems that CR4 was cleared when AP start via lapic_start_cpu()
-	 * Turn on CR4.OSFXSR and CR4.OSXMMEXCPT when SSE options enabled
-	 */
-	u32 cr4_val;
-	cr4_val = readcr4();
-	cr4_val |= (1 << 9 | 1 << 10);
-	writecr4(cr4_val);
-#endif
-	cpu_initialize();
-#if CONFIG_SERIAL_CPU_INIT
-	spin_unlock(&start_cpu_lock);
+        /*
+         * Seems that CR4 was cleared when AP start via lapic_start_cpu()
+         * Turn on CR4.OSFXSR and CR4.OSXMMEXCPT when SSE options enabled
+         */
+        u32 cr4_val;
+        cr4_val = readcr4();
+        cr4_val |= (1 << 9 | 1 << 10);
+        writecr4(cr4_val);
 #endif
-
+	atomic_inc(&active_cpus);
+	cpu_initialize(current_cpu_bus, index);
 	atomic_dec(&active_cpus);
-
-	stop_this_cpu();
-}
-
-static void start_other_cpus(struct bus *cpu_bus, device_t bsp_cpu)
-{
-	device_t cpu;
-	/* Loop through the cpus once getting them started */
-
-	for(cpu = cpu_bus->children; cpu ; cpu = cpu->sibling) {
-		if (cpu->path.type != DEVICE_PATH_APIC) {
-			continue;
-		}
-	#if !CONFIG_SERIAL_CPU_INIT
-		if(cpu==bsp_cpu) {
-			continue;
-		}
-	#endif
-
-		if (!cpu->enabled) {
-			continue;
-		}
-
-		if (cpu->initialized) {
-			continue;
-		}
-
-		if (!start_cpu(cpu)) {
-			/* Record the error in cpu? */
-			printk(BIOS_ERR, "CPU 0x%02x would not start!\n",
-				cpu->path.apic.apic_id);
-		}
-#if CONFIG_SERIAL_CPU_INIT
-		udelay(10);
-#endif
-	}
-
 }
 
 static void wait_other_cpus_stop(struct bus *cpu_bus)
@@ -473,6 +262,7 @@ static void wait_other_cpus_stop(struct bus *cpu_bus)
 				cpu->path.apic.apic_id);
 		}
 	}
+	stop_all_ap_cpus();
 	printk(BIOS_DEBUG, "All AP CPUs stopped (%ld loops)\n", loopcount);
 }
 
@@ -481,10 +271,6 @@ static void wait_other_cpus_stop(struct bus *cpu_bus)
 void initialize_cpus(struct bus *cpu_bus)
 {
 	struct device_path cpu_path;
-	struct cpu_info *info;
-
-	/* Find the info struct for this cpu */
-	info = cpu_info();
 
 #if NEED_LAPIC == 1
 	/* Ensure the local apic is enabled */
@@ -499,9 +285,6 @@ void initialize_cpus(struct bus *cpu_bus)
 	cpu_path.cpu.id       = 0;
 #endif
 
-	/* Find the device structure for the boot cpu */
-	info->cpu = alloc_find_dev(cpu_bus, &cpu_path);
-
 #if CONFIG_SMP
 	copy_secondary_start_to_1m_below(); // why here? In case some day we can start core1 in amd_sibling_init
 #endif
@@ -512,21 +295,11 @@ void initialize_cpus(struct bus *cpu_bus)
 
 	cpus_ready_for_init();
 
-#if CONFIG_SMP
-	#if !CONFIG_SERIAL_CPU_INIT
-	/* start all aps at first, so we can init ECC all together */
-	start_other_cpus(cpu_bus, info->cpu);
-	#endif
-#endif
-
 	/* Initialize the bootstrap processor */
-	cpu_initialize();
+	cpu_initialize(cpu_bus, 0);
 
 #if CONFIG_SMP
-	#if CONFIG_SERIAL_CPU_INIT
-	start_other_cpus(cpu_bus, info->cpu);
-	#endif
-
+	lapic_start_cpus(cpu_bus);
 	/* Now wait the rest of the cpus stop*/
 	wait_other_cpus_stop(cpu_bus);
 #endif
diff --git a/src/cpu/x86/lapic/secondary.S b/src/cpu/x86/lapic/secondary.S
index dc00b082e9..67e44c46df 100644
--- a/src/cpu/x86/lapic/secondary.S
+++ b/src/cpu/x86/lapic/secondary.S
@@ -2,7 +2,7 @@
 #include <cpu/x86/lapic_def.h>
 
 	.text
-	.globl _secondary_start, _secondary_start_end
+	.globl _secondary_start, _secondary_start_end, cpucount
 	.balign 4096
 _secondary_start:
 	.code16
@@ -38,15 +38,25 @@ _secondary_start:
 	/* Load the Interrupt descriptor table */
 	lidt	idtarg
 
-	/* Set the stack pointer, and flag that we are done */
-	xorl	%eax, %eax
-	movl	secondary_stack, %esp
-	movl	%eax, secondary_stack
+	/* increment our cpu index */
+	movl	$1, %eax
+	lock	xadd %eax, cpucount
+	incl	%eax
+	movl	%eax, %ecx
+
+	/* assign stack for this specific cpu */
+	mov	_stack, %esp
+	mov	$CONFIG_STACK_SIZE, %ebx
+	mul	%ebx
+	add	%eax, %esp
 
+	pushl	%ecx
 	call	secondary_cpu_init
 1:	hlt
 	jmp	1b
 
+cpucount:
+	.long	1
 gdtaddr:
 	.word   gdt_limit	/* the table limit */
 	.long   gdt             /* we know the offset */