[PATCH] Hotplug CPU prep V: x86 non-linear CPU numbers

[PATCH] Hotplug CPU prep V: x86 non-linear CPU numbers

[Rusty Russell]

And these are the x86 changes...

Name: x86 Support for Non-linear CPU Numbers Patch 
Author: Rusty Russell
Depends: Hotcpu/nonlinear-cpus.patch.gz

D: This patch fixes up x86 for non-linear CPU numbers.

diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/arch/i386/kernel/apic.c working-2.5.9-nonlinear-cpu/arch/i386/kernel/apic.c
--- linux-2.5.9/arch/i386/kernel/apic.c	Mon Apr 15 11:47:10 2002
+++ working-2.5.9-nonlinear-cpu/arch/i386/kernel/apic.c	Wed Apr 24 15:31:05 2002
@@ -800,10 +800,10 @@
 	 * IRQ APIC event being in synchron with the APIC clock we
 	 * introduce an interrupt skew to spread out timer events.
 	 *
-	 * The number of slices within a 'big' timeslice is smp_num_cpus+1
+	 * The number of slices within a 'big' timeslice is NR_CPUS+1
 	 */
 
-	slice = clocks / (smp_num_cpus+1);
+	slice = clocks / (NR_CPUS+1);
 	printk("cpu: %d, clocks: %d, slice: %d\n", smp_processor_id(), clocks, slice);
 
 	/*
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/arch/i386/kernel/apm.c working-2.5.9-nonlinear-cpu/arch/i386/kernel/apm.c
--- linux-2.5.9/arch/i386/kernel/apm.c	Thu Mar 21 14:14:38 2002
+++ working-2.5.9-nonlinear-cpu/arch/i386/kernel/apm.c	Wed Apr 24 15:29:41 2002
@@ -394,11 +394,7 @@
 #endif
 static int			debug;
 static int			apm_disabled = -1;
-#ifdef CONFIG_SMP
-static int			power_off;
-#else
 static int			power_off = 1;
-#endif
 #ifdef CONFIG_APM_REAL_MODE_POWER_OFF
 static int			realmode_power_off = 1;
 #else
@@ -898,7 +894,7 @@
 	 */
 #ifdef CONFIG_SMP
 	/* Some bioses don't like being called from CPU != 0 */
-	while (cpu_number_map(smp_processor_id()) != 0) {
+	while (smp_processor_id() != 0) {
 		kernel_thread(apm_magic, NULL,
 			CLONE_FS | CLONE_FILES | CLONE_SIGHAND | SIGCHLD);
 		schedule();
@@ -1585,7 +1581,7 @@
 
 	p = buf;
 
-	if ((smp_num_cpus == 1) &&
+	if ((num_online_cpus() == 1) &&
 	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
 		ac_line_status = (bx >> 8) & 0xff;
 		battery_status = bx & 0xff;
@@ -1715,7 +1711,7 @@
 		}
 	}
 
-	if (debug && (smp_num_cpus == 1)) {
+	if (debug && (num_online_cpus() == 1)) {
 		error = apm_get_power_status(&bx, &cx, &dx);
 		if (error)
 			printk(KERN_INFO "apm: power status not available\n");
@@ -1759,7 +1755,7 @@
 		pm_power_off = apm_power_off;
 	register_sysrq_key('o', &sysrq_poweroff_op);
 
-	if (smp_num_cpus == 1) {
+	if (num_online_cpus() == 1) {
 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 		console_blank_hook = apm_console_blank;
 #endif
@@ -1902,10 +1898,6 @@
 		printk(KERN_NOTICE "apm: disabled on user request.\n");
 		return -ENODEV;
 	}
-	if ((smp_num_cpus > 1) && !power_off) {
-		printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
-		return -ENODEV;
-	}
 	if (PM_IS_ACTIVE()) {
 		printk(KERN_NOTICE "apm: overridden by ACPI.\n");
 		return -ENODEV;
@@ -1955,12 +1947,6 @@
 		SET_MODULE_OWNER(apm_proc);
 
 	kernel_thread(apm, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGHAND | SIGCHLD);
-
-	if (smp_num_cpus > 1) {
-		printk(KERN_NOTICE
-		   "apm: disabled - APM is not SMP safe (power off active).\n");
-		return 0;
-	}
 
 	misc_register(&apm_device);
 
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/arch/i386/kernel/bluesmoke.c working-2.5.9-nonlinear-cpu/arch/i386/kernel/bluesmoke.c
--- linux-2.5.9/arch/i386/kernel/bluesmoke.c	Tue Apr 23 11:39:32 2002
+++ working-2.5.9-nonlinear-cpu/arch/i386/kernel/bluesmoke.c	Wed Apr 24 15:29:41 2002
@@ -260,7 +260,9 @@
 {
 	int i;
 
-	for (i=0; i<smp_num_cpus; i++) {
+	for (i=0; i<NR_CPUS; i++) {
+		if (!cpu_online(i))
+			continue;
 		if (i == smp_processor_id())
 			mce_checkregs(i);
 		else
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/arch/i386/kernel/i386_ksyms.c working-2.5.9-nonlinear-cpu/arch/i386/kernel/i386_ksyms.c
--- linux-2.5.9/arch/i386/kernel/i386_ksyms.c	Mon Apr 15 11:47:10 2002
+++ working-2.5.9-nonlinear-cpu/arch/i386/kernel/i386_ksyms.c	Wed Apr 24 15:29:41 2002
@@ -127,7 +127,6 @@
 #ifdef CONFIG_SMP
 EXPORT_SYMBOL(cpu_data);
 EXPORT_SYMBOL(kernel_flag);
-EXPORT_SYMBOL(smp_num_cpus);
 EXPORT_SYMBOL(cpu_online_map);
 EXPORT_SYMBOL_NOVERS(__write_lock_failed);
 EXPORT_SYMBOL_NOVERS(__read_lock_failed);
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/arch/i386/kernel/io_apic.c working-2.5.9-nonlinear-cpu/arch/i386/kernel/io_apic.c
--- linux-2.5.9/arch/i386/kernel/io_apic.c	Tue Apr 23 11:39:32 2002
+++ working-2.5.9-nonlinear-cpu/arch/i386/kernel/io_apic.c	Wed Apr 24 15:34:29 2002
@@ -230,14 +230,14 @@
 inside:
 		if (direction == 1) {
 			cpu++;
-			if (cpu >= smp_num_cpus)
+			if (cpu >= NR_CPUS)
 				cpu = 0;
 		} else {
 			cpu--;
 			if (cpu == -1)
-				cpu = smp_num_cpus-1;
+				cpu = NR_CPUS-1;
 		}
-	} while (!IRQ_ALLOWED(cpu,allowed_mask) ||
+	} while (!cpu_online(cpu) || !IRQ_ALLOWED(cpu,allowed_mask) ||
 			(search_idle && !IDLE_ENOUGH(cpu,now)));
 
 	return cpu;
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/arch/i386/kernel/irq.c working-2.5.9-nonlinear-cpu/arch/i386/kernel/irq.c
--- linux-2.5.9/arch/i386/kernel/irq.c	Tue Apr 23 11:39:32 2002
+++ working-2.5.9-nonlinear-cpu/arch/i386/kernel/irq.c	Wed Apr 24 15:29:41 2002
@@ -138,8 +138,9 @@
 	struct irqaction * action;
 
 	seq_printf(p, "           ");
-	for (j=0; j<smp_num_cpus; j++)
-		seq_printf(p, "CPU%d       ",j);
+	for (j=0; j<NR_CPUS; j++)
+		if (cpu_online(j))
+			p += sprintf(p, "CPU%d       ",j);
 	seq_putc(p, '\n');
 
 	for (i = 0 ; i < NR_IRQS ; i++) {
@@ -150,9 +151,10 @@
 #ifndef CONFIG_SMP
 		seq_printf(p, "%10u ", kstat_irqs(i));
 #else
-		for (j = 0; j < smp_num_cpus; j++)
-			seq_printf(p, "%10u ",
-				kstat.irqs[cpu_logical_map(j)][i]);
+		for (j = 0; j < NR_CPUS; j++)
+			if (cpu_online(j))
+				p += sprintf(p, "%10u ",
+					     kstat.irqs[j][i]);
 #endif
 		seq_printf(p, " %14s", irq_desc[i].handler->typename);
 		seq_printf(p, "  %s", action->name);
@@ -162,13 +164,15 @@
 		seq_putc(p, '\n');
 	}
 	seq_printf(p, "NMI: ");
-	for (j = 0; j < smp_num_cpus; j++)
-		seq_printf(p, "%10u ", nmi_count(cpu_logical_map(j)));
+	for (j = 0; j < NR_CPUS; j++)
+		if (cpu_online(j))
+			p += sprintf(p, "%10u ", nmi_count(j));
 	seq_putc(p, '\n');
 #if CONFIG_X86_LOCAL_APIC
 	seq_printf(p, "LOC: ");
-	for (j = 0; j < smp_num_cpus; j++)
-		seq_printf(p, "%10u ", apic_timer_irqs[cpu_logical_map(j)]);
+	for (j = 0; j < NR_CPUS; j++)
+		if (cpu_online(j))
+			p += sprintf(p, "%10u ", apic_timer_irqs[j]);
 	seq_putc(p, '\n');
 #endif
 	seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
@@ -198,14 +202,14 @@
 
 	printk("\n%s, CPU %d:\n", str, cpu);
 	printk("irq:  %d [",irqs_running());
-	for(i=0;i < smp_num_cpus;i++)
+	for(i=0;i < NR_CPUS;i++)
 		printk(" %d",local_irq_count(i));
 	printk(" ]\nbh:   %d [",spin_is_locked(&global_bh_lock) ? 1 : 0);
-	for(i=0;i < smp_num_cpus;i++)
+	for(i=0;i < NR_CPUS;i++)
 		printk(" %d",local_bh_count(i));
 
 	printk(" ]\nStack dumps:");
-	for(i = 0; i < smp_num_cpus; i++) {
+	for(i = 0; i < NR_CPUS; i++) {
 		unsigned long esp;
 		if (i == cpu)
 			continue;
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/arch/i386/kernel/microcode.c working-2.5.9-nonlinear-cpu/arch/i386/kernel/microcode.c
--- linux-2.5.9/arch/i386/kernel/microcode.c	Tue Apr 23 11:39:32 2002
+++ working-2.5.9-nonlinear-cpu/arch/i386/kernel/microcode.c	Wed Apr 24 15:29:41 2002
@@ -188,7 +188,7 @@
 	}
 	do_update_one(NULL);
 
-	for (i=0; i<smp_num_cpus; i++) {
+	for (i=0; i<NR_CPUS; i++) {
 		err = update_req[i].err;
 		error += err;
 		if (!err) {
@@ -343,8 +343,8 @@
 	}
 	down_write(&microcode_rwsem);
 	if (!mc_applied) {
-		mc_applied = kmalloc(smp_num_cpus*sizeof(struct microcode),
-				GFP_KERNEL);
+		mc_applied = kmalloc(NR_CPUS*sizeof(struct microcode),
+				     GFP_KERNEL);
 		if (!mc_applied) {
 			up_write(&microcode_rwsem);
 			printk(KERN_ERR "microcode: out of memory for saved microcode\n");
@@ -368,7 +368,7 @@
 		ret = -EIO;
 		goto out_fsize;
 	} else {
-		mc_fsize = smp_num_cpus * sizeof(struct microcode);
+		mc_fsize = NR_CPUS * sizeof(struct microcode);
 		ret = (ssize_t)len;
 	}
 out_fsize:
@@ -386,7 +386,7 @@
 		case MICROCODE_IOCFREE:
 			down_write(&microcode_rwsem);
 			if (mc_applied) {
-				int bytes = smp_num_cpus * sizeof(struct microcode);
+				int bytes = NR_CPUS * sizeof(struct microcode);
 
 				devfs_set_file_size(devfs_handle, 0);
 				kfree(mc_applied);
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/arch/i386/kernel/mtrr.c working-2.5.9-nonlinear-cpu/arch/i386/kernel/mtrr.c
--- linux-2.5.9/arch/i386/kernel/mtrr.c	Mon Apr 15 11:47:10 2002
+++ working-2.5.9-nonlinear-cpu/arch/i386/kernel/mtrr.c	Wed Apr 24 15:29:41 2002
@@ -1055,7 +1055,7 @@
     wait_barrier_cache_disable = TRUE;
     wait_barrier_execute = TRUE;
     wait_barrier_cache_enable = TRUE;
-    atomic_set (&undone_count, smp_num_cpus - 1);
+    atomic_set (&undone_count, num_online_cpus() - 1);
     /*  Start the ball rolling on other CPUs  */
     if (smp_call_function (ipi_handler, &data, 1, 0) != 0)
 	panic ("mtrr: timed out waiting for other CPUs\n");
@@ -1064,14 +1064,14 @@
     /*  Wait for all other CPUs to flush and disable their caches  */
     while (atomic_read (&undone_count) > 0) { rep_nop(); barrier(); }
     /* Set up for completion wait and then release other CPUs to change MTRRs*/
-    atomic_set (&undone_count, smp_num_cpus - 1);
+    atomic_set (&undone_count, num_online_cpus() - 1);
     wait_barrier_cache_disable = FALSE;
     set_mtrr_cache_disable (&ctxt);
 
     /*  Wait for all other CPUs to flush and disable their caches  */
     while (atomic_read (&undone_count) > 0) { rep_nop(); barrier(); }
     /* Set up for completion wait and then release other CPUs to change MTRRs*/
-    atomic_set (&undone_count, smp_num_cpus - 1);
+    atomic_set (&undone_count, num_online_cpus() - 1);
     wait_barrier_execute = FALSE;
     (*set_mtrr_up) (reg, base, size, type, FALSE);
     /*  Now wait for other CPUs to complete the function  */
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/arch/i386/kernel/nmi.c working-2.5.9-nonlinear-cpu/arch/i386/kernel/nmi.c
--- linux-2.5.9/arch/i386/kernel/nmi.c	Mon Apr 15 11:47:10 2002
+++ working-2.5.9-nonlinear-cpu/arch/i386/kernel/nmi.c	Wed Apr 24 15:29:41 2002
@@ -81,8 +81,9 @@
 	sti();
 	mdelay((10*1000)/nmi_hz); // wait 10 ticks
 
-	for (j = 0; j < smp_num_cpus; j++) {
-		cpu = cpu_logical_map(j);
+	for (cpu = 0; cpu < NR_CPUS; cpu++) {
+		if (!cpu_online(cpu))
+			continue;
 		if (nmi_count(cpu) - tmp[cpu].__nmi_count <= 5) {
 			printk("CPU#%d: NMI appears to be stuck!\n", cpu);
 			return -1;
@@ -330,7 +331,7 @@
 	 * Just reset the alert counters, (other CPUs might be
 	 * spinning on locks we hold):
 	 */
-	for (i = 0; i < smp_num_cpus; i++)
+	for (i = 0; i < NR_CPUS; i++)
 		alert_counter[i] = 0;
 }
 
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/arch/i386/kernel/smp.c working-2.5.9-nonlinear-cpu/arch/i386/kernel/smp.c
--- linux-2.5.9/arch/i386/kernel/smp.c	Mon Apr 15 11:47:10 2002
+++ working-2.5.9-nonlinear-cpu/arch/i386/kernel/smp.c	Wed Apr 24 15:29:41 2002
@@ -247,18 +247,16 @@
 	 * we get an APIC send error if we try to broadcast.
 	 * thus we have to avoid sending IPIs in this case.
 	 */
-	if (!(smp_num_cpus > 1))
+	if (!(num_online_cpus() > 1))
 		return;
 
 	if (clustered_apic_mode) {
 		// Pointless. Use send_IPI_mask to do this instead
 		int cpu;
 
-		if (smp_num_cpus > 1) {
-			for (cpu = 0; cpu < smp_num_cpus; ++cpu) {
-				if (cpu != smp_processor_id())
-					send_IPI_mask(1 << cpu, vector);
-			}
+		for (cpu = 0; cpu < NR_CPUS; ++cpu) {
+			if (cpu_online(cpu) && cpu != smp_processor_id())
+				send_IPI_mask(1 << cpu, vector);
 		}
 	} else {
 		__send_IPI_shortcut(APIC_DEST_ALLBUT, vector);
@@ -272,7 +270,9 @@
 		// Pointless. Use send_IPI_mask to do this instead
 		int cpu;
 
-		for (cpu = 0; cpu < smp_num_cpus; ++cpu) {
+		for (cpu = 0; cpu < NR_CPUS; ++cpu) {
+			if (!cpu_online(cpu))
+				continue;
 			send_IPI_mask(1 << cpu, vector);
 		}
 	} else {
@@ -544,7 +544,7 @@
  */
 {
 	struct call_data_struct data;
-	int cpus = smp_num_cpus-1;
+	int cpus = num_online_cpus()-1;
 
 	if (!cpus)
 		return 0;
@@ -594,7 +594,6 @@
 void smp_send_stop(void)
 {
 	smp_call_function(stop_this_cpu, NULL, 1, 0);
-	smp_num_cpus = 1;
 
 	__cli();
 	disable_local_APIC();
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/arch/i386/kernel/smpboot.c working-2.5.9-nonlinear-cpu/arch/i386/kernel/smpboot.c
--- linux-2.5.9/arch/i386/kernel/smpboot.c	Mon Apr 15 11:47:10 2002
+++ working-2.5.9-nonlinear-cpu/arch/i386/kernel/smpboot.c	Wed Apr 24 15:31:35 2002
@@ -56,9 +56,6 @@
 /* Setup configured maximum number of CPUs to activate */
 static int max_cpus = -1;
 
-/* Total count of live CPUs */
-int smp_num_cpus = 1;
-
 /* Number of siblings per CPU package */
 int smp_num_siblings = 1;
 int __initdata phys_proc_id[NR_CPUS]; /* Package ID of each logical CPU */
@@ -287,7 +284,8 @@
 		/*
 		 * all APs synchronize but they loop on '== num_cpus'
 		 */
-		while (atomic_read(&tsc_count_start) != smp_num_cpus-1) mb();
+		while (atomic_read(&tsc_count_start) != num_online_cpus()-1)
+			mb();
 		atomic_set(&tsc_count_stop, 0);
 		wmb();
 		/*
@@ -305,21 +303,26 @@
 		/*
 		 * Wait for all APs to leave the synchronization point:
 		 */
-		while (atomic_read(&tsc_count_stop) != smp_num_cpus-1) mb();
+		while (atomic_read(&tsc_count_stop) != num_online_cpus()-1)
+			mb();
 		atomic_set(&tsc_count_start, 0);
 		wmb();
 		atomic_inc(&tsc_count_stop);
 	}
 
 	sum = 0;
-	for (i = 0; i < smp_num_cpus; i++) {
-		t0 = tsc_values[i];
-		sum += t0;
+	for (i = 0; i < NR_CPUS; i++) {
+		if (cpu_online(i)) {
+			t0 = tsc_values[i];
+			sum += t0;
+		}
 	}
-	avg = div64(sum, smp_num_cpus);
+	avg = div64(sum, num_online_cpus());
 
 	sum = 0;
-	for (i = 0; i < smp_num_cpus; i++) {
+	for (i = 0; i < NR_CPUS; i++) {
+		if (!cpu_online(i))
+			continue;
 		delta = tsc_values[i] - avg;
 		if (delta < 0)
 			delta = -delta;
@@ -351,7 +354,7 @@
 	int i;
 
 	/*
-	 * smp_num_cpus is not necessarily known at the time
+	 * num_online_cpus is not necessarily known at the time
 	 * this gets called, so we first wait for the BP to
 	 * finish SMP initialization:
 	 */
@@ -359,14 +362,15 @@
 
 	for (i = 0; i < NR_LOOPS; i++) {
 		atomic_inc(&tsc_count_start);
-		while (atomic_read(&tsc_count_start) != smp_num_cpus) mb();
+		while (atomic_read(&tsc_count_start) != num_online_cpus())
+			mb();
 
 		rdtscll(tsc_values[smp_processor_id()]);
 		if (i == NR_LOOPS-1)
 			write_tsc(0, 0);
 
 		atomic_inc(&tsc_count_stop);
-		while (atomic_read(&tsc_count_stop) != smp_num_cpus) mb();
+		while (atomic_read(&tsc_count_stop) != num_online_cpus()) mb();
 	}
 }
 #undef NR_LOOPS
@@ -1068,7 +1072,6 @@
 		io_apic_irqs = 0;
 #endif
 		cpu_online_map = phys_cpu_present_map = 1;
-		smp_num_cpus = 1;
 		if (APIC_init_uniprocessor())
 			printk(KERN_NOTICE "Local APIC not detected."
 					   " Using dummy APIC emulation.\n");
@@ -1099,7 +1102,6 @@
 		io_apic_irqs = 0;
 #endif
 		cpu_online_map = phys_cpu_present_map = 1;
-		smp_num_cpus = 1;
 		goto smp_done;
 	}
 
@@ -1115,7 +1117,6 @@
 		io_apic_irqs = 0;
 #endif
 		cpu_online_map = phys_cpu_present_map = 1;
-		smp_num_cpus = 1;
 		goto smp_done;
 	}
 
@@ -1196,7 +1197,6 @@
 			(bogosum/(5000/HZ))%100);
 		Dprintk("Before bogocount - setting activated=1.\n");
 	}
-	smp_num_cpus = cpucount + 1;
 
 	if (smp_b_stepping)
 		printk(KERN_WARNING "WARNING: SMP operation may be unreliable with B stepping processors.\n");
@@ -1211,11 +1211,12 @@
 		for (cpu = 0; cpu < NR_CPUS; cpu++)
 			cpu_sibling_map[cpu] = NO_PROC_ID;
 		
-		for (cpu = 0; cpu < smp_num_cpus; cpu++) {
+		for (cpu = 0; cpu < NR_CPUS; cpu++) {
 			int 	i;
-			
-			for (i = 0; i < smp_num_cpus; i++) {
-				if (i == cpu)
+			if (!cpu_online(cpu)) continue;
+
+			for (i = 0; i < NR_CPUS; i++) {
+				if (i == cpu || !cpu_online(i))
 					continue;
 				if (phys_proc_id[cpu] == phys_proc_id[i]) {
 					cpu_sibling_map[cpu] = i;
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/include/asm-i386/hardirq.h working-2.5.9-nonlinear-cpu/include/asm-i386/hardirq.h
--- linux-2.5.9/include/asm-i386/hardirq.h	Wed Apr 24 15:27:50 2002
+++ working-2.5.9-nonlinear-cpu/include/asm-i386/hardirq.h	Wed Apr 24 15:56:55 2002
@@ -51,7 +51,7 @@
 {
 	int i;
 
-	for (i = 0; i < smp_num_cpus; i++)
+	for (i = 0; i < NR_CPUS; i++)
 		if (local_irq_count(i))
 			return 1;
 	return 0;
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.9/include/asm-i386/smp.h working-2.5.9-nonlinear-cpu/include/asm-i386/smp.h
--- linux-2.5.9/include/asm-i386/smp.h	Wed Apr 24 15:27:50 2002
+++ working-2.5.9-nonlinear-cpu/include/asm-i386/smp.h	Wed Apr 24 15:56:55 2002
@@ -69,20 +69,6 @@
 extern void zap_low_mappings (void);
 
 /*
- * On x86 all CPUs are mapped 1:1 to the APIC space.
- * This simplifies scheduling and IPI sending and
- * compresses data structures.
- */
-static inline int cpu_logical_map(int cpu)
-{
-	return cpu;
-}
-static inline int cpu_number_map(int cpu)
-{
-	return cpu;
-}
-
-/*
  * Some lowlevel functions might want to know about
  * the real APIC ID <-> CPU # mapping.
  */
@@ -104,9 +90,23 @@
  * from the initial startup. We map APIC_BASE very early in page_setup(),
  * so this is correct in the x86 case.
  */
-
 #define smp_processor_id() (current_thread_info()->cpu)
 
+#define cpu_online(cpu) (cpu_online_map & (1<<(cpu)))
+
+extern inline unsigned int num_online_cpus(void)
+{
+	return hweight32(cpu_online_map);
+}
+
+extern inline int any_online_cpu(unsigned int mask)
+{
+	if (mask & cpu_online_map)
+		return __ffs(mask & cpu_online_map);
+
+	return -1;
+}
+
 static __inline int hard_smp_processor_id(void)
 {
 	/* we don't want to mark this access volatile - bad code generation */
@@ -119,6 +119,15 @@
 	return GET_APIC_LOGICAL_ID(*(unsigned long *)(APIC_BASE+APIC_LDR));
 }
 
+static inline int cpu_possible(unsigned int cpu)
+{
+	return phys_cpu_present_map & (1 << cpu);
+}
+
+/* Upping and downing of CPUs */
+extern int __cpu_disable(void);
+extern void __cpu_die(unsigned int cpu);
+extern int __cpu_up(unsigned int cpu);
 #endif /* !__ASSEMBLY__ */
 
 #define NO_PROC_ID		0xFF		/* No processor magic marker */

--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Re: [PATCH] Hotplug CPU prep V: x86 non-linear CPU numbers

[Pavel Machek]

Hi!

> @@ -1585,7 +1581,7 @@
>  
>  	p = buf;
>  
> -	if ((smp_num_cpus == 1) &&
> +	if ((num_online_cpus() == 1) &&
>  	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
>  		ac_line_status = (bx >> 8) & 0xff;
>  		battery_status = bx & 0xff;

Are you sure? What if you add another CPU just after the test?
									Pavel
-- 
(about SSSCA) "I don't say this lightly.  However, I really think that the U.S.
no longer is classifiable as a democracy, but rather as a plutocracy." --hpa

Re: [PATCH] Hotplug CPU prep V: x86 non-linear CPU numbers

[Rusty Russell]

In message <20020515101314.GA1152@elf.ucw.cz> you write:
> > @@ -1585,7 +1581,7 @@
> >  
> >  	p = buf;
> >  
> > -	if ((smp_num_cpus == 1) &&
> > +	if ((num_online_cpus() == 1) &&
> >  	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
> >  		ac_line_status = (bx >> 8) & 0xff;
> >  		battery_status = bx & 0xff;
> 
> Are you sure? What if you add another CPU just after the test?

APM is special: what it *really* wants to know is if only CPU 0 is
online (this test will almost certainly fail miserably if the single
online CPU is CPU 1, which previously wasn't possible).

I'll check with the APM maintainer what guarantees he needs: we may
actually need to grab to cpu control lock here.  Anyway apparently I
broke something else in APM.

(BTW, in general, we use magic to avoid locks around num_online_cpus()
et al: we make changes then wait for everyone to voluntarily schedule
before exposing it).

Cheers,
Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Re: [PATCH] Hotplug CPU prep V: x86 non-linear CPU numbers

[Alan Cox]

> APM is special: what it *really* wants to know is if only CPU 0 is
> online (this test will almost certainly fail miserably if the single
> online CPU is CPU 1, which previously wasn't possible).

It wants to know that only one CPU is running. Doesn't matter which.
APM as defined allows for SMP. APM in the real world doesn't work with
SMP but does work well with uniprocessors. People wanted an SMP kernel
on uniprocessor to do the right thing.

It may well be worth having an apm=on type option because some newer setups
especially those using SMM traps for everything seem to get it right

Alan