Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/g…

…it/aegl/linux-2.6

Documentation/cpu-hotplug.txt

@@ -44,10 +44,20 @@ maxcpus=n    Restrict boot time cpus to n. Say if you have 4 cpus, using
              maxcpus=2 will only boot 2. You can choose to bring the
              other cpus later online, read FAQ's for more info.
 
-additional_cpus=n	[x86_64 only] use this to limit hotpluggable cpus.
-                        This option sets
+additional_cpus*=n	Use this to limit hotpluggable cpus. This option sets
 			cpu_possible_map = cpu_present_map + additional_cpus
 
+(*) Option valid only for following architectures
+- x86_64, ia64
+
+ia64 and x86_64 use the number of disabled local apics in ACPI tables MADT
+to determine the number of potentially hot-pluggable cpus. The implementation
+should only rely on this to count the #of cpus, but *MUST* not rely on the
+apicid values in those tables for disabled apics. In the event BIOS doesnt
+mark such hot-pluggable cpus as disabled entries, one could use this
+parameter "additional_cpus=x" to represent those cpus in the cpu_possible_map.
+
+
 CPU maps and such
 -----------------
 [More on cpumaps and primitive to manipulate, please check

arch/ia64/kernel/acpi.c

@@ -761,6 +761,59 @@ int acpi_map_cpu2node(acpi_handle handle, int cpu, long physid)
 	return (0);
 }
 
+int additional_cpus __initdata = -1;
+
+static __init int setup_additional_cpus(char *s)
+{
+	if (s)
+		additional_cpus = simple_strtol(s, NULL, 0);
+
+	return 0;
+}
+
+early_param("additional_cpus", setup_additional_cpus);
+
+/*
+ * cpu_possible_map should be static, it cannot change as cpu's
+ * are onlined, or offlined. The reason is per-cpu data-structures
+ * are allocated by some modules at init time, and dont expect to
+ * do this dynamically on cpu arrival/departure.
+ * cpu_present_map on the other hand can change dynamically.
+ * In case when cpu_hotplug is not compiled, then we resort to current
+ * behaviour, which is cpu_possible == cpu_present.
+ * - Ashok Raj
+ *
+ * Three ways to find out the number of additional hotplug CPUs:
+ * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
+ * - The user can overwrite it with additional_cpus=NUM
+ * - Otherwise don't reserve additional CPUs.
+ */
+__init void prefill_possible_map(void)
+{
+	int i;
+	int possible, disabled_cpus;
+
+	disabled_cpus = total_cpus - available_cpus;
+
+ 	if (additional_cpus == -1) {
+ 		if (disabled_cpus > 0)
+			additional_cpus = disabled_cpus;
+ 		else
+			additional_cpus = 0;
+ 	}
+
+	possible = available_cpus + additional_cpus;
+
+	if (possible > NR_CPUS)
+		possible = NR_CPUS;
+
+	printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
+		possible, max((possible - available_cpus), 0));
+
+	for (i = 0; i < possible; i++)
+		cpu_set(i, cpu_possible_map);
+}
+
 int acpi_map_lsapic(acpi_handle handle, int *pcpu)
 {
 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

arch/ia64/kernel/entry.S

@@ -569,7 +569,9 @@ GLOBAL_ENTRY(ia64_trace_syscall)
 .mem.offset 0,0; st8.spill [r2]=r8		// store return value in slot for r8
 .mem.offset 8,0; st8.spill [r3]=r10		// clear error indication in slot for r10
 	br.call.sptk.many rp=syscall_trace_leave // give parent a chance to catch return value
-.ret3:	br.cond.sptk .work_pending_syscall_end
+.ret3:
+(pUStk)	cmp.eq.unc p6,p0=r0,r0			// p6 <- pUStk
+	br.cond.sptk .work_pending_syscall_end
 
 strace_error:
 	ld8 r3=[r2]				// load pt_regs.r8

arch/ia64/kernel/ia64_ksyms.c

@@ -10,23 +10,8 @@
 
 #include <linux/string.h>
 EXPORT_SYMBOL(memset);
-EXPORT_SYMBOL(memchr);
-EXPORT_SYMBOL(memcmp);
 EXPORT_SYMBOL(memcpy);
-EXPORT_SYMBOL(memmove);
-EXPORT_SYMBOL(memscan);
-EXPORT_SYMBOL(strcat);
-EXPORT_SYMBOL(strchr);
-EXPORT_SYMBOL(strcmp);
-EXPORT_SYMBOL(strcpy);
 EXPORT_SYMBOL(strlen);
-EXPORT_SYMBOL(strncat);
-EXPORT_SYMBOL(strncmp);
-EXPORT_SYMBOL(strncpy);
-EXPORT_SYMBOL(strnlen);
-EXPORT_SYMBOL(strrchr);
-EXPORT_SYMBOL(strstr);
-EXPORT_SYMBOL(strpbrk);
 
 #include <asm/checksum.h>
 EXPORT_SYMBOL(ip_fast_csum);		/* hand-coded assembly */

arch/ia64/kernel/setup.c

@@ -430,6 +430,7 @@ setup_arch (char **cmdline_p)
 	if (early_console_setup(*cmdline_p) == 0)
 		mark_bsp_online();
 
+	parse_early_param();
 #ifdef CONFIG_ACPI
 	/* Initialize the ACPI boot-time table parser */
 	acpi_table_init();
@@ -688,6 +689,9 @@ void
 setup_per_cpu_areas (void)
 {
 	/* start_kernel() requires this... */
+#ifdef CONFIG_ACPI_HOTPLUG_CPU
+	prefill_possible_map();
+#endif
 }
 
 /*

arch/ia64/kernel/smpboot.c

@@ -129,7 +129,7 @@ DEFINE_PER_CPU(int, cpu_state);
 /* Bitmasks of currently online, and possible CPUs */
 cpumask_t cpu_online_map;
 EXPORT_SYMBOL(cpu_online_map);
-cpumask_t cpu_possible_map;
+cpumask_t cpu_possible_map = CPU_MASK_NONE;
 EXPORT_SYMBOL(cpu_possible_map);
 
 cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
@@ -506,9 +506,6 @@ smp_build_cpu_map (void)
 
 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
 		ia64_cpu_to_sapicid[cpu] = -1;
-#ifdef CONFIG_HOTPLUG_CPU
-		cpu_set(cpu, cpu_possible_map);
-#endif
 	}
 
 	ia64_cpu_to_sapicid[0] = boot_cpu_id;

arch/ia64/kernel/time.c

@@ -250,32 +250,27 @@ time_init (void)
 	set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec);
 }
 
-#define SMALLUSECS 100
-
-void
-udelay (unsigned long usecs)
+/*
+ * Generic udelay assumes that if preemption is allowed and the thread
+ * migrates to another CPU, that the ITC values are synchronized across
+ * all CPUs.
+ */
+static void
+ia64_itc_udelay (unsigned long usecs)
 {
-	unsigned long start;
-	unsigned long cycles;
-	unsigned long smallusecs;
+	unsigned long start = ia64_get_itc();
+	unsigned long end = start + usecs*local_cpu_data->cyc_per_usec;
 
-	/*
-	 * Execute the non-preemptible delay loop (because the ITC might
-	 * not be synchronized between CPUS) in relatively short time
-	 * chunks, allowing preemption between the chunks.
-	 */
-	while (usecs > 0) {
-		smallusecs = (usecs > SMALLUSECS) ? SMALLUSECS : usecs;
-		preempt_disable();
-		cycles = smallusecs*local_cpu_data->cyc_per_usec;
-		start = ia64_get_itc();
+	while (time_before(ia64_get_itc(), end))
+		cpu_relax();
+}
 
-		while (ia64_get_itc() - start < cycles)
-			cpu_relax();
+void (*ia64_udelay)(unsigned long usecs) = &ia64_itc_udelay;
 
-		preempt_enable();
-		usecs -= smallusecs;
-	}
+void
+udelay (unsigned long usecs)
+{
+	(*ia64_udelay)(usecs);
 }
 EXPORT_SYMBOL(udelay);
 

arch/ia64/kernel/traps.c

@@ -16,6 +16,7 @@
 #include <linux/module.h>       /* for EXPORT_SYMBOL */
 #include <linux/hardirq.h>
 #include <linux/kprobes.h>
+#include <linux/delay.h>		/* for ssleep() */
 
 #include <asm/fpswa.h>
 #include <asm/ia32.h>
@@ -116,6 +117,13 @@ die (const char *str, struct pt_regs *regs, long err)
 	bust_spinlocks(0);
 	die.lock_owner = -1;
 	spin_unlock_irq(&die.lock);
+
+	if (panic_on_oops) {
+		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
+		ssleep(5);
+		panic("Fatal exception");
+	}
+
   	do_exit(SIGSEGV);
 }