Index: arch/parisc/Kconfig
===================================================================
RCS file: /var/cvs/linux-2.5/arch/parisc/Kconfig,v
retrieving revision 1.23
diff -u -p -r1.23 Kconfig
--- arch/parisc/Kconfig	14 Jul 2003 12:32:20 -0000	1.23
+++ arch/parisc/Kconfig	25 Jul 2003 04:48:34 -0000
@@ -136,9 +136,16 @@ config SMP
 	  If you don't know what to do here, say N.
 
 config PREEMPT
-	bool
-#	bool "Preemptible Kernel"
-	default n
+	bool "Preemptible Kernel"
+	help
+	  This option reduces the latency of the kernel when reacting to
+	  real-time or interactive events by allowing a low priority process to
+	  be preempted even if it is in kernel mode executing a system call.
+	  This allows applications to run more reliably even when the system is
+	  under load.
+
+	  Say Y here if you are building a kernel for a desktop, embedded
+	  or real-time system.  Say N if you are unsure.
 
 config COMPAT
 	bool
Index: arch/parisc/kernel/irq.c
===================================================================
RCS file: /var/cvs/linux-2.5/arch/parisc/kernel/irq.c,v
retrieving revision 1.19
diff -u -p -r1.19 irq.c
--- arch/parisc/kernel/irq.c	5 May 2003 21:34:24 -0000	1.19
+++ arch/parisc/kernel/irq.c	25 Jul 2003 04:48:34 -0000
@@ -329,9 +329,11 @@ unsigned long
 txn_alloc_addr(int virt_irq)
 {
 	static int next_cpu = -1;
+	unsigned long ret;
 
 	next_cpu++; /* assign to "next" CPU we want this bugger on */
 
+	preempt_disable();
 	/* validate entry */
 	while ((next_cpu < NR_CPUS) && !cpu_data[next_cpu].txn_addr)
 		next_cpu++;
@@ -339,7 +341,10 @@ txn_alloc_addr(int virt_irq)
 	if (next_cpu >= NR_CPUS) 
 		next_cpu = 0;	/* nothing else, assign monarch */
 
-	return cpu_data[next_cpu].txn_addr;
+	ret = cpu_data[next_cpu].txn_addr;
+	preempt_enable();
+
+	return ret;
 }
 
 
@@ -380,7 +385,7 @@ txn_alloc_data(int virt_irq, unsigned in
 
 void do_irq(struct irqaction *action, int irq, struct pt_regs * regs)
 {
-	int cpu = smp_processor_id();
+	int cpu = get_cpu();
 
 	irq_enter();
 	++kstat_cpu(cpu).irqs[irq];
@@ -421,6 +426,8 @@ void do_irq(struct irqaction *action, in
 	}
 
 	irq_exit();
+
+	put_cpu();
 }
 
 
Index: arch/parisc/kernel/pa7300lc.c
===================================================================
RCS file: /var/cvs/linux-2.5/arch/parisc/kernel/pa7300lc.c,v
retrieving revision 1.4
diff -u -p -r1.4 pa7300lc.c
--- arch/parisc/kernel/pa7300lc.c	1 Nov 2002 01:04:30 -0000	1.4
+++ arch/parisc/kernel/pa7300lc.c	25 Jul 2003 04:48:34 -0000
@@ -29,7 +29,7 @@ static u32 cpu_hpa(void)
 static void pa7300lc_lpmc(int code, struct pt_regs *regs)
 {
 	u32 hpa;
-	printk(KERN_WARNING "LPMC on CPU %d\n", smp_processor_id());
+	printk(KERN_WARNING "LPMC on CPU %d\n", get_cpu());
 
 	show_regs(regs);
 
@@ -41,6 +41,8 @@ static void pa7300lc_lpmc(int code, stru
 		gsc_readl(hpa+MIOC_CONTROL), gsc_readl(hpa+MIOC_STATUS),
 		gsc_readl(hpa+MDERRADD), gsc_readl(hpa+DMAERR),
 		gsc_readl(hpa+DIOERR), gsc_readl(hpa+HIDMAMEM));
+
+	put_cpu();
 }
 
 void pa7300lc_init(void)
Index: arch/parisc/kernel/perf.c
===================================================================
RCS file: /var/cvs/linux-2.5/arch/parisc/kernel/perf.c,v
retrieving revision 1.11
diff -u -p -r1.11 perf.c
--- arch/parisc/kernel/perf.c	5 Mar 2003 21:15:38 -0000	1.11
+++ arch/parisc/kernel/perf.c	25 Jul 2003 04:48:34 -0000
@@ -529,9 +529,11 @@ static int __init perf_init(void)
 	spin_lock_init(&perf_lock);
 
 	/* TODO: this only lets us access the first cpu.. what to do for SMP? */
+	preempt_disable();
 	cpu_device = cpu_data[0].dev;
 	printk("Performance monitoring counters enabled for %s\n",
 		cpu_data[0].dev->name);
+	preempt_enable();
 
 	return 0;
 }
Index: arch/parisc/kernel/processor.c
===================================================================
RCS file: /var/cvs/linux-2.5/arch/parisc/kernel/processor.c,v
retrieving revision 1.5
diff -u -p -r1.5 processor.c
--- arch/parisc/kernel/processor.c	23 Mar 2003 20:14:52 -0000	1.5
+++ arch/parisc/kernel/processor.c	25 Jul 2003 04:48:34 -0000
@@ -139,6 +139,7 @@ static int __init processor_probe(struct
 	}
 #endif
 
+	preempt_disable();
 	p = &cpu_data[cpuid];
 	boot_cpu_data.cpu_count++;
 
@@ -187,6 +188,7 @@ static int __init processor_probe(struct
 		cpu_irq_actions[cpuid] = actions;
 	}
 #endif
+	preempt_enable();
 	return 0;
 }
 
@@ -248,8 +250,10 @@ void __init collect_boot_cpu_data(void)
 static inline void __init
 init_percpu_prof(int cpunum)
 {
+	preempt_disable();
 	cpu_data[cpunum].prof_counter = 1;
 	cpu_data[cpunum].prof_multiplier = 1;
+	preempt_enable();
 }
 
 
@@ -284,8 +288,10 @@ int __init init_per_cpu(int cpunum)
 		/* FWIW, FP rev/model is a more accurate way to determine
 		** CPU type. CPU rev/model has some ambiguous cases.
 		*/
+		preempt_disable();
 		cpu_data[cpunum].fp_rev = coproc_cfg.revision;
 		cpu_data[cpunum].fp_model = coproc_cfg.model;
+		preempt_enable();
 
 		printk(KERN_INFO  "FP[%d] enabled: Rev %ld Model %ld\n",
 			cpunum, coproc_cfg.revision, coproc_cfg.model);
@@ -323,6 +329,7 @@ show_cpuinfo (struct seq_file *m, void *
 {
 	int	n;
 
+	preempt_disable();
 	for(n=0; n<boot_cpu_data.cpu_count; n++) {
 #ifdef CONFIG_SMP
 		if (0 == cpu_data[n].hpa)
@@ -363,6 +370,7 @@ show_cpuinfo (struct seq_file *m, void *
 		seq_printf(m, "software id\t: %ld\n\n",
 				boot_cpu_data.pdc.model.sw_id);
 	}
+	preempt_enable();
 	return 0;
 }
 
Index: arch/parisc/kernel/setup.c
===================================================================
RCS file: /var/cvs/linux-2.5/arch/parisc/kernel/setup.c,v
retrieving revision 1.14
diff -u -p -r1.14 setup.c
--- arch/parisc/kernel/setup.c	5 May 2003 17:05:48 -0000	1.14
+++ arch/parisc/kernel/setup.c	25 Jul 2003 04:48:34 -0000
@@ -114,7 +114,8 @@ extern void collect_boot_cpu_data(void);
 
 void __init setup_arch(char **cmdline_p)
 {
-	init_per_cpu(smp_processor_id());	/* Set Modes & Enable FP */
+	init_per_cpu(get_cpu());	/* Set Modes & Enable FP */
+	put_cpu();
 
 #ifdef __LP64__
 	printk(KERN_INFO "The 64-bit Kernel has started...\n");
Index: arch/parisc/kernel/smp.c
===================================================================
RCS file: /var/cvs/linux-2.5/arch/parisc/kernel/smp.c,v
retrieving revision 1.14
diff -u -p -r1.14 smp.c
--- arch/parisc/kernel/smp.c	10 Jul 2003 21:56:20 -0000	1.14
+++ arch/parisc/kernel/smp.c	25 Jul 2003 04:48:38 -0000
@@ -139,7 +139,8 @@ halt_processor(void) 
 #else
 	/* REVISIT : redirect I/O Interrupts to another CPU? */
 	/* REVISIT : does PM *know* this CPU isn't available? */
-	clear_bit(smp_processor_id(), (void *)&cpu_online_map);
+	clear_bit(get_cpu(), (void *)&cpu_online_map);
+	put_cpu();
 	local_irq_disable();
 	for (;;)
 		;
@@ -150,7 +151,7 @@ halt_processor(void) 
 irqreturn_t
 ipi_interrupt(int irq, void *dev_id, struct pt_regs *regs) 
 {
-	int this_cpu = smp_processor_id();
+	int this_cpu = get_cpu();
 	struct cpuinfo_parisc *p = &cpu_data[this_cpu];
 	unsigned long ops;
 	unsigned long flags;
@@ -252,10 +253,12 @@ ipi_interrupt(int irq, void *dev_id, str
 				printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
 					this_cpu, which);
 				ops &= ~(1 << which);
-				return;
+				put_cpu();
+				return IRQ_NONE;
 			} /* Switch */
 		} /* while (ops) */
 	}
+	put_cpu();
 	return IRQ_HANDLED;
 }
 
@@ -263,13 +266,16 @@ ipi_interrupt(int irq, void *dev_id, str
 static inline void
 ipi_send(int cpu, enum ipi_message_type op)
 {
-	struct cpuinfo_parisc *p = &cpu_data[cpu];
+	struct cpuinfo_parisc *p;
 	unsigned long flags;
 
+	preempt_disable();
+	p = &cpu_data[cpu];
 	spin_lock_irqsave(&(p->lock),flags);
 	p->pending_ipi |= 1 << op;
 	__raw_writel(IRQ_OFFSET(IPI_IRQ), cpu_data[cpu].hpa);
 	spin_unlock_irqrestore(&(p->lock),flags);
+	preempt_enable();
 }
 
 
@@ -290,9 +296,10 @@ send_IPI_allbutself(enum ipi_message_typ
 	int i;
 	
 	for (i = 0; i < smp_num_cpus; i++) {
-		if (i != smp_processor_id())
+		if (i != get_cpu())
 			send_IPI_single(i, op);
 	}
+	put_cpu();
 }
 
 inline void 
@@ -361,7 +368,8 @@ smp_call_function (void (*func) (void *i
 	smp_call_function_data = NULL;
 	if (atomic_read (&data.unstarted_count) > 0) {
 		printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d)\n",
-		      smp_processor_id());
+		      get_cpu());
+		put_cpu();
 		return -ETIMEDOUT;
 	}
 
@@ -417,13 +425,14 @@ smp_flush_tlb_all(void)
 void 
 smp_do_timer(struct pt_regs *regs)
 {
-	int cpu = smp_processor_id();
+	int cpu = get_cpu();
 	struct cpuinfo_parisc *data = &cpu_data[cpu];
 
         if (!--data->prof_counter) {
 		data->prof_counter = data->prof_multiplier;
 		update_process_times(user_mode(regs));
 	}
+	put_cpu();
 }
 
 /*
@@ -527,6 +536,7 @@ static int __init smp_boot_one_cpu(int c
 	struct task_struct *idle;
 	long timeout;
 
+	preempt_disable();
 	/* 
 	 * Create an idle task for this CPU.  Note the address wed* give 
 	 * to kernel_thread is irrelevant -- it's going to start
@@ -586,6 +596,7 @@ static int __init smp_boot_one_cpu(int c
 	idle = NULL;
 
 	printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
+	preempt_enable();
 	return -1;
 
 alive:
@@ -597,6 +608,7 @@ alive:
 #ifdef ENTRY_SYS_CPUS
 	cpu_data[cpunum].state = STATE_RUNNING;
 #endif
+	preempt_enable();
 	return 0;
 }
 
@@ -615,11 +627,13 @@ alive:
 void __init smp_boot_cpus(void)
 {
 	int i, cpu_count = 1;
-	unsigned long bogosum = cpu_data[0].loops_per_jiffy; /* Count Monarch */
-
+	unsigned long bogosuml;
 	/* REVISIT - assumes first CPU reported by PAT PDC is BSP */
 	int bootstrap_processor=cpu_data[0].cpuid;	/* CPU ID of BSP */
 
+	preempt_disable();
+	bogosuml = cpu_data[0].loops_per_jiffy; /* Count Monarch */
+	bootstrap_processor=cpu_data[0].cpuid;	/* CPU ID of BSP */
 	/* Setup BSP mappings */
 	printk(KERN_DEBUG "SMP: bootstrap CPU ID is %d\n",bootstrap_processor);
 	init_task.thread_info->cpu = bootstrap_processor; 
@@ -635,6 +649,7 @@ void __init smp_boot_cpus(void)
 	/* Nothing to do when told not to.  */
 	if (max_cpus == 0) {
 		printk(KERN_INFO "SMP mode deactivated.\n");
+		preempt_enable();
 		return;
 	}
 
@@ -680,6 +695,7 @@ void __init smp_boot_cpus(void)
 #ifdef PER_CPU_IRQ_REGION
 	ipi_init();
 #endif
+	preempt_enable();
 	return;
 }
 
@@ -709,8 +725,10 @@ void __init smp_prepare_cpus(unsigned in
 
 void __devinit smp_prepare_boot_cpu(void)
 {
+	preempt_disable();
 	set_bit(smp_processor_id(), &cpu_online_map);
 	set_bit(smp_processor_id(), &cpu_present_mask);
+	preempt_enable();
 }
 
 int __devinit __cpu_up(unsigned int cpu)
Index: arch/parisc/kernel/time.c
===================================================================
RCS file: /var/cvs/linux-2.5/arch/parisc/kernel/time.c,v
retrieving revision 1.14
diff -u -p -r1.14 time.c
--- arch/parisc/kernel/time.c	14 Jul 2003 12:32:21 -0000	1.14
+++ arch/parisc/kernel/time.c	25 Jul 2003 04:48:38 -0000
@@ -81,7 +81,7 @@ irqreturn_t timer_interrupt(int irq, voi
 	long now;
 	long next_tick;
 	int nticks;
-	int cpu = smp_processor_id();
+	int cpu = get_cpu();
 
 	parisc_do_profile(regs);
 
@@ -128,6 +128,7 @@ irqreturn_t timer_interrupt(int irq, voi
 	if (cpu == 0 && !atomic_read(&power_tasklet.count))
 		tasklet_schedule(&power_tasklet);
 
+	put_cpu();
 	return IRQ_HANDLED;
 }
 
@@ -149,6 +150,7 @@ gettimeoffset (void)
 	long last_tick;
 	long elapsed_cycles;
 
+	preempt_disable();
 	/* it_value is the intended time of the next tick */
 	last_tick = cpu_data[smp_processor_id()].it_value;
 
@@ -160,6 +162,7 @@ gettimeoffset (void)
 	elapsed_cycles = mfctl(16) - last_tick;
 
 	/* the precision of this math could be improved */
+	preempt_enable();
 	return elapsed_cycles / (PAGE0->mem_10msec / 10000);
 #else
 	return 0;
@@ -236,7 +239,7 @@ void __init time_init(void)
 
 	next_tick = mfctl(16);
 	next_tick += clocktick;
-	cpu_data[smp_processor_id()].it_value = next_tick;
+	cpu_data[get_cpu()].it_value = next_tick;
 
 	/* kick off Itimer (CR16) */
 	mtctl(next_tick, 16);
@@ -253,5 +256,6 @@ void __init time_init(void)
 	        xtime.tv_sec = 0;
 		xtime.tv_nsec = 0;
 	}
+	put_cpu();
 }
 
Index: arch/parisc/kernel/traps.c
===================================================================
RCS file: /var/cvs/linux-2.5/arch/parisc/kernel/traps.c,v
retrieving revision 1.26
diff -u -p -r1.26 traps.c
--- arch/parisc/kernel/traps.c	19 Jul 2003 07:41:09 -0000	1.26
+++ arch/parisc/kernel/traps.c	25 Jul 2003 04:48:38 -0000
@@ -325,8 +325,9 @@ int handle_toc(void)
 
 static void default_trap(int code, struct pt_regs *regs)
 {
-	printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id());
+	printk(KERN_ERR "Trap %d on CPU %d\n", code, get_cpu());
 	show_regs(regs);
+	put_cpu();
 }
 
 void (*cpu_lpmc) (int code, struct pt_regs *regs) = default_trap;
Index: include/asm-parisc/hardirq.h
===================================================================
RCS file: /var/cvs/linux-2.5/include/asm-parisc/hardirq.h,v
retrieving revision 1.10
diff -u -p -r1.10 hardirq.h
--- include/asm-parisc/hardirq.h	27 May 2003 17:28:21 -0000	1.10
+++ include/asm-parisc/hardirq.h	25 Jul 2003 04:48:48 -0000
@@ -34,18 +34,18 @@ typedef struct {
  *
  * - bits 0-7 are the preemption count (max preemption depth: 256)
  * - bits 8-15 are the softirq count (max # of softirqs: 256)
- * - bits 16-31 are the hardirq count (max # of hardirqs: 65536)
+ * - bits 16-29 are the hardirq count (max # of hardirqs: 16384)
  *
  * - (bit 63 is the PREEMPT_ACTIVE flag---not currently implemented.)
  *
  * PREEMPT_MASK: 0x000000ff
  * SOFTIRQ_MASK: 0x0000ff00
- * HARDIRQ_MASK: 0xffff0000
+ * HARDIRQ_MASK: 0x3fff0000
  */
 
 #define PREEMPT_BITS	8
 #define SOFTIRQ_BITS	8
-#define HARDIRQ_BITS	16
+#define HARDIRQ_BITS	14
 
 #define PREEMPT_SHIFT	0
 #define SOFTIRQ_SHIFT	(PREEMPT_SHIFT + PREEMPT_BITS)
@@ -88,8 +88,7 @@ typedef struct {
 #define irq_enter()		(preempt_count() += HARDIRQ_OFFSET)
 
 #ifdef CONFIG_PREEMPT
-# error CONFIG_PREEMT currently not supported.
-# define in_atomic()	 BUG()
+# define in_atomic()     ((preempt_count() & ~PREEMPT_ACTIVE) != kernel_locked())
 # define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
 #else
 # define in_atomic()	(preempt_count() != 0)
Index: include/asm-parisc/thread_info.h
===================================================================
RCS file: /var/cvs/linux-2.5/include/asm-parisc/thread_info.h,v
retrieving revision 1.9
diff -u -p -r1.9 thread_info.h
--- include/asm-parisc/thread_info.h	14 Jun 2003 22:15:58 -0000	1.9
+++ include/asm-parisc/thread_info.h	25 Jul 2003 04:48:48 -0000
@@ -49,7 +49,8 @@ struct thread_info {
 
 #endif /* !__ASSEMBLY */
 
-#define PREEMPT_ACTIVE          0x4000000
+#define PREEMPT_ACTIVE_BIT      30
+#define PREEMPT_ACTIVE          (1<<PREEMPT_ACTIVE_BIT)
 
 /*
  * thread information flags