[PATCH] alpha smp fixes

From Jeff.Wiedemeier@hp.com:

Misc alpha smp updates for 2.5 tree.

arch/alpha/kernel/smp.c

@@ -72,14 +72,13 @@ static int smp_secondary_alive __initdata = 0;
 
 /* Which cpus ids came online.  */
 unsigned long cpu_present_mask;
+volatile unsigned long cpu_online_map;
 
 /* cpus reported in the hwrpb */
 static unsigned long hwrpb_cpu_present_mask __initdata = 0;
 
-static int max_cpus = -1;	/* Command-line limitation.  */
 int smp_num_probed;		/* Internal processor count */
 int smp_num_cpus = 1;		/* Number that came online.  */
-int smp_threads_ready;		/* True once the per process idle is forked. */
 cycles_t cacheflush_time;
 unsigned long cache_decay_ticks;
 
@@ -87,22 +86,6 @@ extern void calibrate_delay(void);
 extern asmlinkage void entInt(void);
 
 
-static int __init nosmp(char *str)
-{
-	max_cpus = 0;
-	return 1;
-}
-
-__setup("nosmp", nosmp);
-
-static int __init maxcpus(char *str)
-{
-	get_option(&str, &max_cpus);
-	return 1;
-}
-
-__setup("maxcpus", maxcpus);
-
 
 /*
  * Called by both boot and secondaries to move global data into
@@ -151,6 +134,11 @@ smp_callin(void)
 {
 	int cpuid = hard_smp_processor_id();
 
+	if (test_and_set_bit(cpuid, &cpu_online_map)) {
+		printk("??, cpu 0x%x already present??\n", cpuid);
+		BUG();
+	}
+
 	/* Turn on machine checks.  */
 	wrmces(7);
 
@@ -181,10 +169,6 @@ smp_callin(void)
 	wmb();
 	smp_secondary_alive = 1;
 
-	/* Wait for the go code.  */
-	while (!smp_threads_ready)
-		barrier();
-
 	DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n",
 	      cpuid, current, current->active_mm));
 
@@ -432,7 +416,7 @@ fork_by_hand(void)
 	/* Don't care about the contents of regs since we'll never
 	   reschedule the forked task. */
 	struct pt_regs regs;
-	return do_fork(CLONE_VM|CLONE_IDLETASK, 0, &regs, 0, NULL);
+	return do_fork(CLONE_VM|CLONE_IDLETASK, 0, &regs, 0, NULL, NULL);
 }
 
 /*
@@ -542,13 +526,12 @@ setup_smp(void)
 }
 
 /*
- * Called by smp_init bring all the secondaries online and hold them.
+ * Called by smp_init prepare the secondaries
  */
 void __init
-smp_boot_cpus(void)
+smp_prepare_cpus(unsigned int max_cpus)
 {
 	int cpu_count, i;
-	unsigned long bogosum;
 
 	/* Take care of some initial bookkeeping.  */
 	memset(ipi_data, 0, sizeof(ipi_data));
@@ -559,6 +542,9 @@ smp_boot_cpus(void)
 	smp_tune_scheduling(boot_cpuid);
 	smp_setup_percpu_timer(boot_cpuid);
 
+	/* We have already have the boot CPU online.. */
+	set_bit(boot_cpuid, &cpu_online_map);
+
 	/* Nothing to do on a UP box, or when told not to.  */
 	if (smp_num_probed == 1 || max_cpus == 0) {
 		cpu_present_mask = 1UL << boot_cpuid;
@@ -569,44 +555,20 @@ smp_boot_cpus(void)
 	printk(KERN_INFO "SMP starting up secondaries.\n");
 
 	cpu_count = 1;
-	for (i = 0; i < NR_CPUS; i++) {
+	for (i = 0; (i < NR_CPUS) && (cpu_count < max_cpus); i++) {
 		if (i == boot_cpuid)
 			continue;
 
 		if (((hwrpb_cpu_present_mask >> i) & 1) == 0)
 			continue;
 
-		if (smp_boot_one_cpu(i))
-			continue;
-
 		cpu_present_mask |= 1UL << i;
 		cpu_count++;
 	}
 
-	if (cpu_count == 1) {
-		printk(KERN_ERR "SMP: Only one lonely processor alive.\n");
-		return;
-	}
-
-	bogosum = 0;
-	for (i = 0; i < NR_CPUS; i++) {
-		if (cpu_present_mask & (1UL << i))
-			bogosum += cpu_data[i].loops_per_jiffy;
-	}
-	printk(KERN_INFO "SMP: Total of %d processors activated "
-	       "(%lu.%02lu BogoMIPS).\n",
-	       cpu_count, (bogosum + 2500) / (500000/HZ),
-	       ((bogosum + 2500) / (5000/HZ)) % 100);
-
 	smp_num_cpus = cpu_count;
 }
 
-void __init
-smp_prepare_cpus(unsigned int max_cpus)
-{
-	smp_boot_cpus();
-}
-
 void __devinit
 smp_prepare_boot_cpu(void)
 {
@@ -616,14 +578,26 @@ smp_prepare_boot_cpu(void)
 int __devinit
 __cpu_up(unsigned int cpu)
 {
+	smp_boot_one_cpu(cpu);
+
 	return cpu_online(cpu) ? 0 : -ENOSYS;
 }
 
 void __init
 smp_cpus_done(unsigned int max_cpus)
 {
-	smp_threads_ready = 1;
-	mb();
+	int cpu;
+	unsigned long bogosum = 0;
+
+	for(cpu = 0; cpu < NR_CPUS; cpu++) 
+		if (cpu_online(cpu))
+			bogosum += cpu_data[cpu].loops_per_jiffy;
+	
+	printk(KERN_INFO "SMP: Total of %d processors activated "
+	       "(%lu.%02lu BogoMIPS).\n",
+	       num_online_cpus(), 
+	       (bogosum + 2500) / (500000/HZ),
+	       ((bogosum + 2500) / (5000/HZ)) % 100);
 }
 
 
@@ -909,7 +883,7 @@ int
 smp_call_function (void (*func) (void *info), void *info, int retry, int wait)
 {
 	return smp_call_function_on_cpu (func, info, retry, wait,
-					 cpu_present_mask);
+					 cpu_online_map);
 }
 
 static void

include/asm-alpha/smp.h

@@ -3,6 +3,7 @@
 
 #include <linux/config.h>
 #include <linux/threads.h>
+#include <linux/bitops.h>
 #include <asm/pal.h>
 
 /* HACK: Cabrio WHAMI return value is bogus if more than 8 bits used.. :-( */
@@ -21,7 +22,6 @@ __hard_smp_processor_id(void)
 
 #ifdef CONFIG_SMP
 
-#include <linux/threads.h>
 #include <asm/irq.h>
 
 struct cpuinfo_alpha {
@@ -45,12 +45,17 @@ extern struct cpuinfo_alpha cpu_data[NR_CPUS];
 #define smp_processor_id()	(current_thread_info()->cpu)
 
 extern unsigned long cpu_present_mask;
+extern volatile unsigned long cpu_online_map;
 extern int smp_num_cpus;
 
-#define cpu_online_map		cpu_present_mask
-#define num_online_cpus()	(smp_num_cpus)
-#define cpu_online(cpu)		(cpu_present_mask & (1<<(cpu)))
-#define cpu_possible(cpu)	cpu_online(cpu)
+#define cpu_possible(cpu)	(cpu_present_mask & (1UL << (cpu)))
+#define cpu_online(cpu)		(cpu_online_map & (1UL << (cpu)))
+
+static inline int
+num_online_cpus(void)
+{
+	return hweight64(cpu_online_map);
+}
 
 extern int smp_call_function_on_cpu(void (*func) (void *info), void *info,int retry, int wait, unsigned long cpu);