Merge branch 'parisc-4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull parisc updates from Helge Deller:

 - add Kernel address space layout randomization support

 - re-enable interrupts earlier now that we have a working IRQ stack

 - optimize the timer interrupt function to better cope with missed
   timer irqs

 - fix error return code in parisc perf code (by Dan Carpenter)

 - fix PAT debug code

* 'parisc-4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Optimize timer interrupt function
  parisc: perf: return -EFAULT on error
  parisc: Enhance CPU detection code on PAT machines
  parisc: Re-enable interrupts early
  parisc: Enable KASLR

arch/parisc/Kconfig

@@ -7,6 +7,7 @@ config PARISC
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_SYSCALL_TRACEPOINTS
 	select ARCH_WANT_FRAME_POINTERS
+	select ARCH_HAS_ELF_RANDOMIZE
 	select RTC_CLASS
 	select RTC_DRV_GENERIC
 	select INIT_ALL_POSSIBLE

arch/parisc/include/asm/elf.h

@@ -348,9 +348,10 @@ struct pt_regs;	/* forward declaration... */
 
 #define ELF_HWCAP	0
 
-#define STACK_RND_MASK	(is_32bit_task() ? \
-				0x7ff >> (PAGE_SHIFT - 12) : \
-				0x3ffff >> (PAGE_SHIFT - 12))
+/* Masks for stack and mmap randomization */
+#define BRK_RND_MASK	(is_32bit_task() ? 0x07ffUL : 0x3ffffUL)
+#define MMAP_RND_MASK	(is_32bit_task() ? 0x1fffUL : 0x3ffffUL)
+#define STACK_RND_MASK	MMAP_RND_MASK
 
 struct mm_struct;
 extern unsigned long arch_randomize_brk(struct mm_struct *);

arch/parisc/include/asm/pdcpat.h

@@ -289,7 +289,7 @@ extern int pdc_pat_cell_get_number(struct pdc_pat_cell_num *cell_info);
 extern int pdc_pat_cell_module(unsigned long *actcnt, unsigned long ploc, unsigned long mod, unsigned long view_type, void *mem_addr);
 extern int pdc_pat_cell_num_to_loc(void *, unsigned long);
 
-extern int pdc_pat_cpu_get_number(struct pdc_pat_cpu_num *cpu_info, void *hpa);
+extern int pdc_pat_cpu_get_number(struct pdc_pat_cpu_num *cpu_info, unsigned long hpa);
 
 extern int pdc_pat_pd_get_addr_map(unsigned long *actual_len, void *mem_addr, unsigned long count, unsigned long offset);
 

arch/parisc/include/asm/processor.h

@@ -93,9 +93,7 @@ struct system_cpuinfo_parisc {
 /* Per CPU data structure - ie varies per CPU.  */
 struct cpuinfo_parisc {
 	unsigned long it_value;     /* Interval Timer at last timer Intr */
-	unsigned long it_delta;     /* Interval delta (tic_10ms / HZ * 100) */
 	unsigned long irq_count;    /* number of IRQ's since boot */
-	unsigned long irq_max_cr16; /* longest time to handle a single IRQ */
 	unsigned long cpuid;        /* aka slot_number or set to NO_PROC_ID */
 	unsigned long hpa;          /* Host Physical address */
 	unsigned long txn_addr;     /* MMIO addr of EIR or id_eid */
@@ -103,8 +101,6 @@ struct cpuinfo_parisc {
 	unsigned long pending_ipi;  /* bitmap of type ipi_message_type */
 #endif
 	unsigned long bh_count;     /* number of times bh was invoked */
-	unsigned long prof_counter; /* per CPU profiling support */
-	unsigned long prof_multiplier;	/* per CPU profiling support */
 	unsigned long fp_rev;
 	unsigned long fp_model;
 	unsigned int state;

arch/parisc/kernel/entry.S

@@ -878,6 +878,9 @@ ENTRY_CFI(syscall_exit_rfi)
 	STREG   %r19,PT_SR7(%r16)
 
 intr_return:
+	/* NOTE: Need to enable interrupts incase we schedule. */
+	ssm     PSW_SM_I, %r0
+
 	/* check for reschedule */
 	mfctl   %cr30,%r1
 	LDREG   TI_FLAGS(%r1),%r19	/* sched.h: TIF_NEED_RESCHED */
@@ -904,11 +907,6 @@ intr_check_sig:
 	LDREG	PT_IASQ1(%r16), %r20
 	cmpib,COND(=),n 0,%r20,intr_restore /* backward */
 
-	/* NOTE: We need to enable interrupts if we have to deliver
-	 * signals. We used to do this earlier but it caused kernel
-	 * stack overflows. */
-	ssm     PSW_SM_I, %r0
-
 	copy	%r0, %r25			/* long in_syscall = 0 */
 #ifdef CONFIG_64BIT
 	ldo	-16(%r30),%r29			/* Reference param save area */
@@ -960,10 +958,6 @@ intr_do_resched:
 	cmpib,COND(=)	0, %r20, intr_do_preempt
 	nop
 
-	/* NOTE: We need to enable interrupts if we schedule.  We used
-	 * to do this earlier but it caused kernel stack overflows. */
-	ssm     PSW_SM_I, %r0
-
 #ifdef CONFIG_64BIT
 	ldo	-16(%r30),%r29		/* Reference param save area */
 #endif

arch/parisc/kernel/firmware.c

@@ -1258,7 +1258,7 @@ int pdc_pat_cell_module(unsigned long *actcnt, unsigned long ploc, unsigned long
  *
  * Retrieve the cpu number for the cpu at the specified HPA.
  */
-int pdc_pat_cpu_get_number(struct pdc_pat_cpu_num *cpu_info, void *hpa)
+int pdc_pat_cpu_get_number(struct pdc_pat_cpu_num *cpu_info, unsigned long hpa)
 {
 	int retval;
 	unsigned long flags;

arch/parisc/kernel/inventory.c

@@ -216,9 +216,9 @@ pat_query_module(ulong pcell_loc, ulong mod_index)
 	register_parisc_device(dev);	/* advertise device */
 
 #ifdef DEBUG_PAT
-	pdc_pat_cell_mod_maddr_block_t io_pdc_cell;
 	/* dump what we see so far... */
 	switch (PAT_GET_ENTITY(dev->mod_info)) {
+		pdc_pat_cell_mod_maddr_block_t io_pdc_cell;
 		unsigned long i;
 
 	case PAT_ENTITY_PROC:
@@ -259,9 +259,9 @@ pat_query_module(ulong pcell_loc, ulong mod_index)
 				pa_pdc_cell->mod[4 + i * 3]);	/* finish (ie end) */
 			printk(KERN_DEBUG 
 				"  IO_VIEW %ld: 0x%016lx 0x%016lx 0x%016lx\n", 
-				i, io_pdc_cell->mod[2 + i * 3],	/* type */
-				io_pdc_cell->mod[3 + i * 3],	/* start */
-				io_pdc_cell->mod[4 + i * 3]);	/* finish (ie end) */
+				i, io_pdc_cell.mod[2 + i * 3],	/* type */
+				io_pdc_cell.mod[3 + i * 3],	/* start */
+				io_pdc_cell.mod[4 + i * 3]);	/* finish (ie end) */
 		}
 		printk(KERN_DEBUG "\n");
 		break;

arch/parisc/kernel/perf.c

@@ -301,7 +301,6 @@ static ssize_t perf_read(struct file *file, char __user *buf, size_t cnt, loff_t
 static ssize_t perf_write(struct file *file, const char __user *buf, size_t count, 
 	loff_t *ppos)
 {
-	int err;
 	size_t image_size;
 	uint32_t image_type;
 	uint32_t interface_type;
@@ -320,8 +319,8 @@ static ssize_t perf_write(struct file *file, const char __user *buf, size_t coun
 	if (count != sizeof(uint32_t))
 		return -EIO;
 
-	if ((err = copy_from_user(&image_type, buf, sizeof(uint32_t))) != 0) 
-		return err;
+	if (copy_from_user(&image_type, buf, sizeof(uint32_t)))
+		return -EFAULT;
 
 	/* Get the interface type and test type */
    	interface_type = (image_type >> 16) & 0xffff;

arch/parisc/kernel/process.c

@@ -276,11 +276,7 @@ void *dereference_function_descriptor(void *ptr)
 
 static inline unsigned long brk_rnd(void)
 {
-	/* 8MB for 32bit, 1GB for 64bit */
-	if (is_32bit_task())
-		return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;
-	else
-		return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;
+	return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
 }
 
 unsigned long arch_randomize_brk(struct mm_struct *mm)

arch/parisc/kernel/processor.c

@@ -78,11 +78,6 @@ DEFINE_PER_CPU(struct cpuinfo_parisc, cpu_data);
 static void
 init_percpu_prof(unsigned long cpunum)
 {
-	struct cpuinfo_parisc *p;
-
-	p = &per_cpu(cpu_data, cpunum);
-	p->prof_counter = 1;
-	p->prof_multiplier = 1;
 }
 
 
@@ -99,6 +94,7 @@ static int processor_probe(struct parisc_device *dev)
 	unsigned long txn_addr;
 	unsigned long cpuid;
 	struct cpuinfo_parisc *p;
+	struct pdc_pat_cpu_num cpu_info __maybe_unused;
 
 #ifdef CONFIG_SMP
 	if (num_online_cpus() >= nr_cpu_ids) {
@@ -123,10 +119,6 @@ static int processor_probe(struct parisc_device *dev)
 		ulong status;
 		unsigned long bytecnt;
 	        pdc_pat_cell_mod_maddr_block_t *pa_pdc_cell;
-#undef USE_PAT_CPUID
-#ifdef USE_PAT_CPUID
-		struct pdc_pat_cpu_num cpu_info;
-#endif
 
 		pa_pdc_cell = kmalloc(sizeof (*pa_pdc_cell), GFP_KERNEL);
 		if (!pa_pdc_cell)
@@ -145,22 +137,27 @@ static int processor_probe(struct parisc_device *dev)
 
 		kfree(pa_pdc_cell);
 
+		/* get the cpu number */
+		status = pdc_pat_cpu_get_number(&cpu_info, dev->hpa.start);
+		BUG_ON(PDC_OK != status);
+
+		pr_info("Logical CPU #%lu is physical cpu #%lu at location "
+			"0x%lx with hpa %pa\n",
+			cpuid, cpu_info.cpu_num, cpu_info.cpu_loc,
+			&dev->hpa.start);
+
+#undef USE_PAT_CPUID
 #ifdef USE_PAT_CPUID
 /* We need contiguous numbers for cpuid. Firmware's notion
  * of cpuid is for physical CPUs and we just don't care yet.
  * We'll care when we need to query PAT PDC about a CPU *after*
  * boot time (ie shutdown a CPU from an OS perspective).
  */
-		/* get the cpu number */
-		status = pdc_pat_cpu_get_number(&cpu_info, dev->hpa.start);
-
-		BUG_ON(PDC_OK != status);
-
 		if (cpu_info.cpu_num >= NR_CPUS) {
-			printk(KERN_WARNING "IGNORING CPU at 0x%x,"
+			printk(KERN_WARNING "IGNORING CPU at %pa,"
 				" cpu_slot_id > NR_CPUS"
 				" (%ld > %d)\n",
-				dev->hpa.start, cpu_info.cpu_num, NR_CPUS);
+				&dev->hpa.start, cpu_info.cpu_num, NR_CPUS);
 			/* Ignore CPU since it will only crash */
 			boot_cpu_data.cpu_count--;
 			return 1;

arch/parisc/kernel/sys_parisc.c

@@ -225,19 +225,17 @@ static unsigned long mmap_rnd(void)
 {
 	unsigned long rnd = 0;
 
-	/*
-	*  8 bits of randomness in 32bit mmaps, 20 address space bits
-	* 28 bits of randomness in 64bit mmaps, 40 address space bits
-	*/
-	if (current->flags & PF_RANDOMIZE) {
-		if (is_32bit_task())
-			rnd = get_random_int() % (1<<8);
-		else
-			rnd = get_random_int() % (1<<28);
-	}
+	if (current->flags & PF_RANDOMIZE)
+		rnd = get_random_int() & MMAP_RND_MASK;
+
 	return rnd << PAGE_SHIFT;
 }
 
+unsigned long arch_mmap_rnd(void)
+{
+	return (get_random_int() & MMAP_RND_MASK) << PAGE_SHIFT;
+}
+
 static unsigned long mmap_legacy_base(void)
 {
 	return TASK_UNMAPPED_BASE + mmap_rnd();

arch/parisc/kernel/time.c

@@ -59,10 +59,9 @@ static unsigned long clocktick __read_mostly;	/* timer cycles per tick */
  */
 irqreturn_t __irq_entry timer_interrupt(int irq, void *dev_id)
 {
-	unsigned long now, now2;
+	unsigned long now;
 	unsigned long next_tick;
-	unsigned long cycles_elapsed, ticks_elapsed = 1;
-	unsigned long cycles_remainder;
+	unsigned long ticks_elapsed = 0;
 	unsigned int cpu = smp_processor_id();
 	struct cpuinfo_parisc *cpuinfo = &per_cpu(cpu_data, cpu);
 
@@ -71,102 +70,49 @@ irqreturn_t __irq_entry timer_interrupt(int irq, void *dev_id)
 
 	profile_tick(CPU_PROFILING);
 
-	/* Initialize next_tick to the expected tick time. */
+	/* Initialize next_tick to the old expected tick time. */
 	next_tick = cpuinfo->it_value;
 
-	/* Get current cycle counter (Control Register 16). */
+	/* Calculate how many ticks have elapsed. */
+	do {
+		++ticks_elapsed;
+		next_tick += cpt;
 		now = mfctl(16);
+	} while (next_tick - now > cpt);
 
-	cycles_elapsed = now - next_tick;
-
-	if ((cycles_elapsed >> 6) < cpt) {
-		/* use "cheap" math (add/subtract) instead
-		 * of the more expensive div/mul method
-		 */
-		cycles_remainder = cycles_elapsed;
-		while (cycles_remainder > cpt) {
-			cycles_remainder -= cpt;
-			ticks_elapsed++;
-		}
-	} else {
-		/* TODO: Reduce this to one fdiv op */
-		cycles_remainder = cycles_elapsed % cpt;
-		ticks_elapsed += cycles_elapsed / cpt;
-	}
-
-	/* convert from "division remainder" to "remainder of clock tick" */
-	cycles_remainder = cpt - cycles_remainder;
-
-	/* Determine when (in CR16 cycles) next IT interrupt will fire.
-	 * We want IT to fire modulo clocktick even if we miss/skip some.
-	 * But those interrupts don't in fact get delivered that regularly.
-	 */
-	next_tick = now + cycles_remainder;
-
+	/* Store (in CR16 cycles) up to when we are accounting right now. */
 	cpuinfo->it_value = next_tick;
 
-	/* Program the IT when to deliver the next interrupt.
-	 * Only bottom 32-bits of next_tick are writable in CR16!
-	 */
-	mtctl(next_tick, 16);
+	/* Go do system house keeping. */
+	if (cpu == 0)
+		xtime_update(ticks_elapsed);
 
-	/* Skip one clocktick on purpose if we missed next_tick.
+	update_process_times(user_mode(get_irq_regs()));
+
+	/* Skip clockticks on purpose if we know we would miss those.
 	 * The new CR16 must be "later" than current CR16 otherwise
 	 * itimer would not fire until CR16 wrapped - e.g 4 seconds
 	 * later on a 1Ghz processor. We'll account for the missed
-	 * tick on the next timer interrupt.
+	 * ticks on the next timer interrupt.
+	 * We want IT to fire modulo clocktick even if we miss/skip some.
+	 * But those interrupts don't in fact get delivered that regularly.
 	 *
 	 * "next_tick - now" will always give the difference regardless
 	 * if one or the other wrapped. If "now" is "bigger" we'll end up
 	 * with a very large unsigned number.
 	 */
-	now2 = mfctl(16);
-	if (next_tick - now2 > cpt)
-		mtctl(next_tick+cpt, 16);
-
-#if 1
-/*
- * GGG: DEBUG code for how many cycles programming CR16 used.
- */
-	if (unlikely(now2 - now > 0x3000)) 	/* 12K cycles */
-		printk (KERN_CRIT "timer_interrupt(CPU %d): SLOW! 0x%lx cycles!"
-			" cyc %lX rem %lX "
-			" next/now %lX/%lX\n",
-			cpu, now2 - now, cycles_elapsed, cycles_remainder,
-			next_tick, now );
-#endif
-
-	/* Can we differentiate between "early CR16" (aka Scenario 1) and
-	 * "long delay" (aka Scenario 3)? I don't think so.
-	 *
-	 * Timer_interrupt will be delivered at least a few hundred cycles
-	 * after the IT fires. But it's arbitrary how much time passes
-	 * before we call it "late". I've picked one second.
-	 *
-	 * It's important NO printk's are between reading CR16 and
-	 * setting up the next value. May introduce huge variance.
-	 */
-	if (unlikely(ticks_elapsed > HZ)) {
-		/* Scenario 3: very long delay?  bad in any case */
-		printk (KERN_CRIT "timer_interrupt(CPU %d): delayed!"
-			" cycles %lX rem %lX "
-			" next/now %lX/%lX\n",
-			cpu,
-			cycles_elapsed, cycles_remainder,
-			next_tick, now );
-	}
+	while (next_tick - mfctl(16) > cpt)
+		next_tick += cpt;
 
-	/* Done mucking with unreliable delivery of interrupts.
-	 * Go do system house keeping.
+	/* Program the IT when to deliver the next interrupt.
+	 * Only bottom 32-bits of next_tick are writable in CR16!
+	 * Timer interrupt will be delivered at least a few hundred cycles
+	 * after the IT fires, so if we are too close (<= 500 cycles) to the
+	 * next cycle, simply skip it.
 	 */
-
-	if (!--cpuinfo->prof_counter) {
-		cpuinfo->prof_counter = cpuinfo->prof_multiplier;
-		update_process_times(user_mode(get_irq_regs()));
-	}
-
-	if (cpu == 0)
-		xtime_update(ticks_elapsed);
+	if (next_tick - mfctl(16) <= 500)
+		next_tick += cpt;
+	mtctl(next_tick, 16);
 
 	return IRQ_HANDLED;
 }