diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 433e75a2ee9afa2ff315bf39a97a429ebc64f6a4..cad060f288cf51e089bfb9cf7b6e879064bc0989 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -13,6 +13,7 @@ config PARISC
 	select BUG
 	select HAVE_PERF_EVENTS
 	select GENERIC_ATOMIC64 if !64BIT
+	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select HAVE_GENERIC_HARDIRQS
 	select BROKEN_RODATA
 	select GENERIC_IRQ_PROBE
@@ -242,6 +243,14 @@ config SMP
 
 	  If you don't know what to do here, say N.
 
+config IRQSTACKS
+	bool "Use separate kernel stacks when processing interrupts"
+	default n
+	help
+	  If you say Y here the kernel will use separate kernel stacks
+	  for handling hard and soft interrupts.  This can help avoid
+	  overflowing the process kernel stacks.
+
 config HOTPLUG_CPU
 	bool
 	default y if SMP
diff --git a/arch/parisc/Kconfig.debug b/arch/parisc/Kconfig.debug
index bc989e522a045c17ca4514478b7cb5ef9d77fc4d..08a332f6ee874d814df7a97615dd44821add3c13 100644
--- a/arch/parisc/Kconfig.debug
+++ b/arch/parisc/Kconfig.debug
@@ -13,3 +13,14 @@ config DEBUG_RODATA
          If in doubt, say "N".
 
 endmenu
+
+config DEBUG_STACKOVERFLOW
+	bool "Check for stack overflows"
+	default y
+	depends on DEBUG_KERNEL
+	---help---
+	  Say Y here if you want to check the overflows of kernel, IRQ
+	  and exception stacks. This option will cause messages of the
+	  stacks in detail when free stack space drops below a certain
+	  limit.
+	  If in doubt, say "N".
diff --git a/arch/parisc/Makefile b/arch/parisc/Makefile
index 113e28206503ae55e8915d7382d17dc059a20eee..2f967cc6649e0cab325136624a614af4f0784281 100644
--- a/arch/parisc/Makefile
+++ b/arch/parisc/Makefile
@@ -24,9 +24,7 @@ CHECKFLAGS	+= -D__hppa__=1
 LIBGCC		= $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
 MACHINE		:= $(shell uname -m)
-ifeq ($(MACHINE),parisc*)
-NATIVE		:= 1
-endif
+NATIVE		:= $(if $(filter parisc%,$(MACHINE)),1,0)
 
 ifdef CONFIG_64BIT
 UTS_MACHINE	:= parisc64
diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h
index f38e1984b242f8df63e470bc878d62e8d3f4c447..472886ceab1dde20c5ac3928c4f71dd2642d547a 100644
--- a/arch/parisc/include/asm/atomic.h
+++ b/arch/parisc/include/asm/atomic.h
@@ -229,6 +229,29 @@ static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
 
 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 
+/*
+ * atomic64_dec_if_positive - decrement by 1 if old value positive
+ * @v: pointer of type atomic_t
+ *
+ * The function returns the old value of *v minus 1, even if
+ * the atomic variable, v, was not decremented.
+ */
+static inline long atomic64_dec_if_positive(atomic64_t *v)
+{
+	long c, old, dec;
+	c = atomic64_read(v);
+	for (;;) {
+		dec = c - 1;
+		if (unlikely(dec < 0))
+			break;
+		old = atomic64_cmpxchg((v), c, dec);
+		if (likely(old == c))
+			break;
+		c = old;
+	}
+	return dec;
+}
+
 #endif /* !CONFIG_64BIT */
 
 
diff --git a/arch/parisc/include/asm/dma-mapping.h b/arch/parisc/include/asm/dma-mapping.h
index 106b395688e1d167bf764a76de70d5d58e4109d7..d0eae5f2bd8795e244d2a086f30e7d78439050f3 100644
--- a/arch/parisc/include/asm/dma-mapping.h
+++ b/arch/parisc/include/asm/dma-mapping.h
@@ -46,6 +46,9 @@ extern struct hppa_dma_ops pcx_dma_ops;
 
 extern struct hppa_dma_ops *hppa_dma_ops;
 
+#define dma_alloc_attrs(d, s, h, f, a) dma_alloc_coherent(d, s, h, f)
+#define dma_free_attrs(d, s, h, f, a) dma_free_coherent(d, s, h, f)
+
 static inline void *
 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
 		   gfp_t flag)
diff --git a/arch/parisc/include/asm/hardirq.h b/arch/parisc/include/asm/hardirq.h
index 0d68184a76cb54006aeb5142c54315564eabd7aa..12373c4dababec920c0ec42f120064011567d4b6 100644
--- a/arch/parisc/include/asm/hardirq.h
+++ b/arch/parisc/include/asm/hardirq.h
@@ -1,11 +1,41 @@
 /* hardirq.h: PA-RISC hard IRQ support.
  *
  * Copyright (C) 2001 Matthew Wilcox <matthew@wil.cx>
+ * Copyright (C) 2013 Helge Deller <deller@gmx.de>
  */
 
 #ifndef _PARISC_HARDIRQ_H
 #define _PARISC_HARDIRQ_H
 
-#include <asm-generic/hardirq.h>
+#include <linux/cache.h>
+#include <linux/threads.h>
+#include <linux/irq.h>
+
+typedef struct {
+	unsigned int __softirq_pending;
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+	unsigned int kernel_stack_usage;
+#endif
+#ifdef CONFIG_SMP
+	unsigned int irq_resched_count;
+	unsigned int irq_call_count;
+#endif
+	unsigned int irq_tlb_count;
+} ____cacheline_aligned irq_cpustat_t;
+
+DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
+
+#define __ARCH_IRQ_STAT
+#define __IRQ_STAT(cpu, member) (irq_stat[cpu].member)
+#define inc_irq_stat(member)	this_cpu_inc(irq_stat.member)
+#define local_softirq_pending()	this_cpu_read(irq_stat.__softirq_pending)
+
+#define __ARCH_SET_SOFTIRQ_PENDING
+
+#define set_softirq_pending(x)	\
+		this_cpu_write(irq_stat.__softirq_pending, (x))
+#define or_softirq_pending(x)	this_cpu_or(irq_stat.__softirq_pending, (x))
+
+#define ack_bad_irq(irq) WARN(1, "unexpected IRQ trap at vector %02x\n", irq)
 
 #endif /* _PARISC_HARDIRQ_H */
diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h
index 09b54a57a48d025283af4816d319e14a911e6158..064015547d1e32be0a968ba946bc54f8db362895 100644
--- a/arch/parisc/include/asm/processor.h
+++ b/arch/parisc/include/asm/processor.h
@@ -20,8 +20,6 @@
 
 #endif /* __ASSEMBLY__ */
 
-#define KERNEL_STACK_SIZE 	(4*PAGE_SIZE)
-
 /*
  * Default implementation of macro that returns current
  * instruction pointer ("program counter").
@@ -60,6 +58,23 @@
 
 #ifndef __ASSEMBLY__
 
+/*
+ * IRQ STACK - used for irq handler
+ */
+#ifdef __KERNEL__
+
+#define IRQ_STACK_SIZE      (4096 << 2) /* 16k irq stack size */
+
+union irq_stack_union {
+	unsigned long stack[IRQ_STACK_SIZE/sizeof(unsigned long)];
+};
+
+DECLARE_PER_CPU(union irq_stack_union, irq_stack_union);
+
+void call_on_stack(unsigned long p1, void *func, unsigned long new_stack);
+
+#endif /* __KERNEL__ */
+
 /*
  * Data detected about CPUs at boot time which is the same for all CPU's.
  * HP boxes are SMP - ie identical processors.
@@ -97,7 +112,6 @@ struct cpuinfo_parisc {
 	unsigned long txn_addr;     /* MMIO addr of EIR or id_eid */
 #ifdef CONFIG_SMP
 	unsigned long pending_ipi;  /* bitmap of type ipi_message_type */
-	unsigned long ipi_count;    /* number ipi Interrupts */
 #endif
 	unsigned long bh_count;     /* number of times bh was invoked */
 	unsigned long prof_counter; /* per CPU profiling support */
diff --git a/arch/parisc/include/asm/thread_info.h b/arch/parisc/include/asm/thread_info.h
index 6182832e5b6c9c166597f2627ecc9463a38a7d1b..540c88fa8f863d44adcc254fe9a3917cf015aa4d 100644
--- a/arch/parisc/include/asm/thread_info.h
+++ b/arch/parisc/include/asm/thread_info.h
@@ -40,7 +40,7 @@ struct thread_info {
 
 /* thread information allocation */
 
-#define THREAD_SIZE_ORDER            2
+#define THREAD_SIZE_ORDER	2 /* PA-RISC requires at least 16k stack */
 /* Be sure to hunt all references to this down when you change the size of
  * the kernel stack */
 #define THREAD_SIZE             (PAGE_SIZE << THREAD_SIZE_ORDER)
diff --git a/arch/parisc/include/asm/tlbflush.h b/arch/parisc/include/asm/tlbflush.h
index 8f1a8100bf2df394f0ca78e90dbec9f33d33125d..5273da991e062c841ac40efdb0f3174a4df8cde3 100644
--- a/arch/parisc/include/asm/tlbflush.h
+++ b/arch/parisc/include/asm/tlbflush.h
@@ -22,6 +22,8 @@ extern spinlock_t pa_tlb_lock;
 extern void flush_tlb_all(void);
 extern void flush_tlb_all_local(void *);
 
+#define smp_flush_tlb_all()	flush_tlb_all()
+
 /*
  * flush_tlb_mm()
  *
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 83ded26cad065af6cda1d1dc725dec381e48a669..65fb4cbc3a0ffd88f7f100870e8b0c952de573e7 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -606,7 +606,7 @@ void clear_user_highpage(struct page *page, unsigned long vaddr)
 	/* Clear using TMPALIAS region.  The page doesn't need to
 	   be flushed but the kernel mapping needs to be purged.  */
 
-	vto = kmap_atomic(page, KM_USER0);
+	vto = kmap_atomic(page);
 
 	/* The PA-RISC 2.0 Architecture book states on page F-6:
 	   "Before a write-capable translation is enabled, *all*
@@ -641,8 +641,8 @@ void copy_user_highpage(struct page *to, struct page *from,
 	   the `to' page must be flushed in copy_user_page_asm since
 	   it can be used to bring in executable code.  */
 
-	vfrom = kmap_atomic(from, KM_USER0);
-	vto = kmap_atomic(to, KM_USER1);
+	vfrom = kmap_atomic(from);
+	vto = kmap_atomic(to);
 
 	purge_kernel_dcache_page_asm((unsigned long)vto);
 	purge_tlb_start(flags);
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index f33201bf8977208358b87c92911cb149a68f618a..4bb96ad9b0b14ddd1cb066bc21b304d861059f38 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -400,7 +400,15 @@
 #if PT_NLEVELS == 3
 	extru		\va,31-ASM_PMD_SHIFT,ASM_BITS_PER_PMD,\index
 #else
+# if defined(CONFIG_64BIT)
+	extrd,u		\va,63-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
+  #else
+  # if PAGE_SIZE > 4096
+	extru		\va,31-ASM_PGDIR_SHIFT,32-ASM_PGDIR_SHIFT,\index
+  # else
 	extru		\va,31-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
+  # endif
+# endif
 #endif
 	dep             %r0,31,PAGE_SHIFT,\pmd  /* clear offset */
 	copy		%r0,\pte
@@ -615,7 +623,7 @@
 
 	.text
 
-	.align	PAGE_SIZE
+	.align 4096
 
 ENTRY(fault_vector_20)
 	/* First vector is invalid (0) */
@@ -825,11 +833,6 @@ ENTRY(syscall_exit_rfi)
 	STREG   %r19,PT_SR7(%r16)
 
 intr_return:
-	/* NOTE: Need to enable interrupts incase we schedule. */
-	ssm     PSW_SM_I, %r0
-
-intr_check_resched:
-
 	/* check for reschedule */
 	mfctl   %cr30,%r1
 	LDREG   TI_FLAGS(%r1),%r19	/* sched.h: TIF_NEED_RESCHED */
@@ -856,6 +859,11 @@ 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 */
@@ -907,6 +915,10 @@ 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
@@ -1694,7 +1706,8 @@ ENTRY(sys_\name\()_wrapper)
 	ldo	TASK_REGS(%r1),%r1
 	reg_save %r1
 	mfctl	%cr27, %r28
-	b	sys_\name
+	ldil	L%sys_\name, %r31
+	be	R%sys_\name(%sr4,%r31)
 	STREG	%r28, PT_CR27(%r1)
 ENDPROC(sys_\name\()_wrapper)
 	.endm
@@ -1997,6 +2010,47 @@ ftrace_stub:
 ENDPROC(return_to_handler)
 #endif	/* CONFIG_FUNCTION_TRACER */
 
+#ifdef CONFIG_IRQSTACKS
+/* void call_on_stack(unsigned long param1, void *func,
+		      unsigned long new_stack) */
+ENTRY(call_on_stack)
+	copy	%sp, %r1
+
+	/* Regarding the HPPA calling conventions for function pointers,
+	   we assume the PIC register is not changed across call.  For
+	   CONFIG_64BIT, the argument pointer is left to point at the
+	   argument region allocated for the call to call_on_stack. */
+# ifdef CONFIG_64BIT
+	/* Switch to new stack.  We allocate two 128 byte frames.  */
+	ldo	256(%arg2), %sp
+	/* Save previous stack pointer and return pointer in frame marker */
+	STREG	%rp, -144(%sp)
+	/* Calls always use function descriptor */
+	LDREG	16(%arg1), %arg1
+	bve,l	(%arg1), %rp
+	STREG	%r1, -136(%sp)
+	LDREG	-144(%sp), %rp
+	bve	(%rp)
+	LDREG	-136(%sp), %sp
+# else
+	/* Switch to new stack.  We allocate two 64 byte frames.  */
+	ldo	128(%arg2), %sp
+	/* Save previous stack pointer and return pointer in frame marker */
+	STREG	%r1, -68(%sp)
+	STREG	%rp, -84(%sp)
+	/* Calls use function descriptor if PLABEL bit is set */
+	bb,>=,n	%arg1, 30, 1f
+	depwi	0,31,2, %arg1
+	LDREG	0(%arg1), %arg1
+1:
+	be,l	0(%sr4,%arg1), %sr0, %r31
+	copy	%r31, %rp
+	LDREG	-84(%sp), %rp
+	bv	(%rp)
+	LDREG	-68(%sp), %sp
+# endif /* CONFIG_64BIT */
+ENDPROC(call_on_stack)
+#endif /* CONFIG_IRQSTACKS */
 
 get_register:
 	/*
diff --git a/arch/parisc/kernel/hpmc.S b/arch/parisc/kernel/hpmc.S
index 5595a2f311816d3d5e24420e5598563c4815d3a8..e158b6fbf1b472e2abd62277206518192f57b7ac 100644
--- a/arch/parisc/kernel/hpmc.S
+++ b/arch/parisc/kernel/hpmc.S
@@ -55,13 +55,13 @@
 	 * IODC requires 7K byte stack.  That leaves 1K byte for os_hpmc.
 	 */
 
-	.align	PAGE_SIZE
+	.align 4096
 hpmc_stack:
 	.block 16384
 
 #define HPMC_IODC_BUF_SIZE 0x8000
 
-	.align	PAGE_SIZE
+	.align 4096
 hpmc_iodc_buf:
 	.block HPMC_IODC_BUF_SIZE
 
diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
index 8094d3ed3b646328be21fd26738298a365089555..e255db0bb7619cf92e8581cae017f01f20c4718d 100644
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -152,6 +152,39 @@ static struct irq_chip cpu_interrupt_type = {
 	.irq_retrigger	= NULL,
 };
 
+DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
+#define irq_stats(x)		(&per_cpu(irq_stat, x))
+
+/*
+ * /proc/interrupts printing for arch specific interrupts
+ */
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+	int j;
+
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+	seq_printf(p, "%*s: ", prec, "STK");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->kernel_stack_usage);
+	seq_printf(p, "  Kernel stack usage\n");
+#endif
+#ifdef CONFIG_SMP
+	seq_printf(p, "%*s: ", prec, "RES");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
+	seq_printf(p, "  Rescheduling interrupts\n");
+	seq_printf(p, "%*s: ", prec, "CAL");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
+	seq_printf(p, "  Function call interrupts\n");
+#endif
+	seq_printf(p, "%*s: ", prec, "TLB");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
+	seq_printf(p, "  TLB shootdowns\n");
+	return 0;
+}
+
 int show_interrupts(struct seq_file *p, void *v)
 {
 	int i = *(loff_t *) v, j;
@@ -219,6 +252,9 @@ int show_interrupts(struct seq_file *p, void *v)
 		raw_spin_unlock_irqrestore(&desc->lock, flags);
 	}
 
+	if (i == NR_IRQS)
+		arch_show_interrupts(p, 3);
+
 	return 0;
 }
 
@@ -330,6 +366,66 @@ static inline int eirr_to_irq(unsigned long eirr)
 	return (BITS_PER_LONG - bit) + TIMER_IRQ;
 }
 
+int sysctl_panic_on_stackoverflow = 1;
+
+static inline void stack_overflow_check(struct pt_regs *regs)
+{
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+	#define STACK_MARGIN	(256*6)
+
+	/* Our stack starts directly behind the thread_info struct. */
+	unsigned long stack_start = (unsigned long) current_thread_info();
+	unsigned long sp = regs->gr[30];
+	unsigned long stack_usage;
+	unsigned int *last_usage;
+
+	/* if sr7 != 0, we interrupted a userspace process which we do not want
+	 * to check for stack overflow. We will only check the kernel stack. */
+	if (regs->sr[7])
+		return;
+
+	/* calculate kernel stack usage */
+	stack_usage = sp - stack_start;
+	last_usage = &per_cpu(irq_stat.kernel_stack_usage, smp_processor_id());
+
+	if (unlikely(stack_usage > *last_usage))
+		*last_usage = stack_usage;
+
+	if (likely(stack_usage < (THREAD_SIZE - STACK_MARGIN)))
+		return;
+
+	pr_emerg("stackcheck: %s will most likely overflow kernel stack "
+		 "(sp:%lx, stk bottom-top:%lx-%lx)\n",
+		current->comm, sp, stack_start, stack_start + THREAD_SIZE);
+
+	if (sysctl_panic_on_stackoverflow)
+		panic("low stack detected by irq handler - check messages\n");
+#endif
+}
+
+#ifdef CONFIG_IRQSTACKS
+DEFINE_PER_CPU(union irq_stack_union, irq_stack_union);
+
+static void execute_on_irq_stack(void *func, unsigned long param1)
+{
+	unsigned long *irq_stack_start;
+	unsigned long irq_stack;
+	int cpu = smp_processor_id();
+
+	irq_stack_start = &per_cpu(irq_stack_union, cpu).stack[0];
+	irq_stack = (unsigned long) irq_stack_start;
+	irq_stack = ALIGN(irq_stack, 16); /* align for stack frame usage */
+
+	BUG_ON(*irq_stack_start); /* report bug if we were called recursive. */
+	*irq_stack_start = 1;
+
+	/* This is where we switch to the IRQ stack. */
+	call_on_stack(param1, func, irq_stack);
+
+	*irq_stack_start = 0;
+}
+#endif /* CONFIG_IRQSTACKS */
+
 /* ONLY called from entry.S:intr_extint() */
 void do_cpu_irq_mask(struct pt_regs *regs)
 {
@@ -364,7 +460,13 @@ void do_cpu_irq_mask(struct pt_regs *regs)
 		goto set_out;
 	}
 #endif
+	stack_overflow_check(regs);
+
+#ifdef CONFIG_IRQSTACKS
+	execute_on_irq_stack(&generic_handle_irq, irq);
+#else
 	generic_handle_irq(irq);
+#endif /* CONFIG_IRQSTACKS */
 
  out:
 	irq_exit();
@@ -420,6 +522,4 @@ void __init init_IRQ(void)
 	cpu_eiem = EIEM_MASK(TIMER_IRQ);
 #endif
         set_eiem(cpu_eiem);	/* EIEM : enable all external intr */
-
 }
-
diff --git a/arch/parisc/kernel/pacache.S b/arch/parisc/kernel/pacache.S
index 312b48422a56c0c314b3d0f51b07ab95c3db8951..5e1de6072be57f0c92ce04950284fe7f10c5bf4c 100644
--- a/arch/parisc/kernel/pacache.S
+++ b/arch/parisc/kernel/pacache.S
@@ -563,6 +563,15 @@ ENDPROC(copy_page_asm)
  *          %r23 physical page (shifted for tlb insert) of "from" translation
  */
 
+        /* Drop prot bits and convert to page addr for iitlbt and idtlbt */
+        #define PAGE_ADD_SHIFT  (PAGE_SHIFT-12)
+        .macro          convert_phys_for_tlb_insert20  phys
+        extrd,u         \phys, 56-PAGE_ADD_SHIFT, 32-PAGE_ADD_SHIFT, \phys
+#if _PAGE_SIZE_ENCODING_DEFAULT
+        depdi           _PAGE_SIZE_ENCODING_DEFAULT, 63, (63-58), \phys
+#endif
+	.endm
+
 	/*
 	 * We can't do this since copy_user_page is used to bring in
 	 * file data that might have instructions. Since the data would
@@ -589,15 +598,14 @@ ENTRY(copy_user_page_asm)
 	sub		%r25, %r1, %r23
 
 	ldil		L%(TMPALIAS_MAP_START), %r28
-	/* FIXME for different page sizes != 4k */
 #ifdef CONFIG_64BIT
 #if (TMPALIAS_MAP_START >= 0x80000000)
 	depdi		0, 31,32, %r28		/* clear any sign extension */
 #endif
-	extrd,u		%r26,56,32, %r26	/* convert phys addr to tlb insert format */
-	extrd,u		%r23,56,32, %r23	/* convert phys addr to tlb insert format */
+	convert_phys_for_tlb_insert20 %r26	/* convert phys addr to tlb insert format */
+	convert_phys_for_tlb_insert20 %r23	/* convert phys addr to tlb insert format */
 	depd		%r24,63,22, %r28	/* Form aliased virtual address 'to' */
-	depdi		0, 63,12, %r28		/* Clear any offset bits */
+	depdi		0, 63,PAGE_SHIFT, %r28  /* Clear any offset bits */
 	copy		%r28, %r29
 	depdi		1, 41,1, %r29		/* Form aliased virtual address 'from' */
 #else
@@ -747,11 +755,10 @@ ENTRY(clear_user_page_asm)
 #ifdef CONFIG_64BIT
 #if (TMPALIAS_MAP_START >= 0x80000000)
 	depdi		0, 31,32, %r28		/* clear any sign extension */
-	/* FIXME: page size dependend */
 #endif
-	extrd,u		%r26, 56,32, %r26	/* convert phys addr to tlb insert format */
+	convert_phys_for_tlb_insert20 %r26	/* convert phys addr to tlb insert format */
 	depd		%r25, 63,22, %r28	/* Form aliased virtual address 'to' */
-	depdi		0, 63,12, %r28		/* Clear any offset bits */
+	depdi		0, 63,PAGE_SHIFT, %r28	/* Clear any offset bits */
 #else
 	extrw,u		%r26, 24,25, %r26	/* convert phys addr to tlb insert format */
 	depw		%r25, 31,22, %r28	/* Form aliased virtual address 'to' */
@@ -832,11 +839,10 @@ ENTRY(flush_dcache_page_asm)
 #ifdef CONFIG_64BIT
 #if (TMPALIAS_MAP_START >= 0x80000000)
 	depdi		0, 31,32, %r28		/* clear any sign extension */
-	/* FIXME: page size dependend */
 #endif
-	extrd,u		%r26, 56,32, %r26	/* convert phys addr to tlb insert format */
+	convert_phys_for_tlb_insert20 %r26	/* convert phys addr to tlb insert format */
 	depd		%r25, 63,22, %r28	/* Form aliased virtual address 'to' */
-	depdi		0, 63,12, %r28		/* Clear any offset bits */
+	depdi		0, 63,PAGE_SHIFT, %r28	/* Clear any offset bits */
 #else
 	extrw,u		%r26, 24,25, %r26	/* convert phys addr to tlb insert format */
 	depw		%r25, 31,22, %r28	/* Form aliased virtual address 'to' */
@@ -909,11 +915,10 @@ ENTRY(flush_icache_page_asm)
 #ifdef CONFIG_64BIT
 #if (TMPALIAS_MAP_START >= 0x80000000)
 	depdi		0, 31,32, %r28		/* clear any sign extension */
-	/* FIXME: page size dependend */
 #endif
-	extrd,u		%r26, 56,32, %r26	/* convert phys addr to tlb insert format */
+	convert_phys_for_tlb_insert20 %r26	/* convert phys addr to tlb insert format */
 	depd		%r25, 63,22, %r28	/* Form aliased virtual address 'to' */
-	depdi		0, 63,12, %r28		/* Clear any offset bits */
+	depdi		0, 63,PAGE_SHIFT, %r28  /* Clear any offset bits */
 #else
 	extrw,u		%r26, 24,25, %r26	/* convert phys addr to tlb insert format */
 	depw		%r25, 31,22, %r28	/* Form aliased virtual address 'to' */
@@ -959,7 +964,7 @@ ENTRY(flush_icache_page_asm)
 	fic,m		%r1(%sr4,%r28)
 	fic,m		%r1(%sr4,%r28)
 	fic,m		%r1(%sr4,%r28)
-	cmpb,COND(<<)		%r28, %r25,1b
+	cmpb,COND(<<)	%r28, %r25,1b
 	fic,m		%r1(%sr4,%r28)
 
 	sync
diff --git a/arch/parisc/kernel/setup.c b/arch/parisc/kernel/setup.c
index a3328c2616b0a6cf3f99eaff2fa2968cc58e1105..76b63e726a539ee912bea1077d00370603e1f538 100644
--- a/arch/parisc/kernel/setup.c
+++ b/arch/parisc/kernel/setup.c
@@ -129,6 +129,8 @@ void __init setup_arch(char **cmdline_p)
 	printk(KERN_INFO "The 32-bit Kernel has started...\n");
 #endif
 
+	printk(KERN_INFO "Default page size is %dKB.\n", (int)(PAGE_SIZE / 1024));
+
 	pdc_console_init();
 
 #ifdef CONFIG_64BIT
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index fd1bb1519c2b114be60f3d75089b7d81f29adbd7..e3614fb343e5eca796f919482e8873ae48e17c19 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -127,7 +127,7 @@ ipi_interrupt(int irq, void *dev_id)
 	unsigned long flags;
 
 	/* Count this now; we may make a call that never returns. */
-	p->ipi_count++;
+	inc_irq_stat(irq_call_count);
 
 	mb();	/* Order interrupt and bit testing. */
 
@@ -155,6 +155,7 @@ ipi_interrupt(int irq, void *dev_id)
 				
 			case IPI_RESCHEDULE:
 				smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
+				inc_irq_stat(irq_resched_count);
 				scheduler_ipi();
 				break;
 
@@ -262,17 +263,6 @@ void arch_send_call_function_single_ipi(int cpu)
 	send_IPI_single(cpu, IPI_CALL_FUNC_SINGLE);
 }
 
-/*
- * Flush all other CPU's tlb and then mine.  Do this with on_each_cpu()
- * as we want to ensure all TLB's flushed before proceeding.
- */
-
-void
-smp_flush_tlb_all(void)
-{
-	on_each_cpu(flush_tlb_all_local, NULL, 1);
-}
-
 /*
  * Called by secondaries to update state and initialize CPU registers.
  */
diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S
index 5e055240f00bb1f0b98f882db1f1ec5103e8c6ed..e767ab733e321e5619b919a9b8684ac70c35ba9b 100644
--- a/arch/parisc/kernel/syscall.S
+++ b/arch/parisc/kernel/syscall.S
@@ -1,12 +1,35 @@
 /* 
  * Linux/PA-RISC Project (http://www.parisc-linux.org/)
  * 
- * System call entry code Copyright (c) Matthew Wilcox 1999 <willy@bofh.ai>
+ * System call entry code / Linux gateway page
+ * Copyright (c) Matthew Wilcox 1999 <willy@bofh.ai>
  * Licensed under the GNU GPL.
  * thanks to Philipp Rumpf, Mike Shaver and various others
  * sorry about the wall, puffin..
  */
 
+/*
+How does the Linux gateway page on PA-RISC work?
+------------------------------------------------
+The Linux gateway page on PA-RISC is "special".
+It actually has PAGE_GATEWAY bits set (this is linux terminology; in parisc
+terminology it's Execute, promote to PL0) in the page map.  So anything
+executing on this page executes with kernel level privilege (there's more to it
+than that: to have this happen, you also have to use a branch with a ,gate
+completer to activate the privilege promotion).  The upshot is that everything
+that runs on the gateway page runs at kernel privilege but with the current
+user process address space (although you have access to kernel space via %sr2).
+For the 0x100 syscall entry, we redo the space registers to point to the kernel
+address space (preserving the user address space in %sr3), move to wide mode if
+required, save the user registers and branch into the kernel syscall entry
+point.  For all the other functions, we execute at kernel privilege but don't
+flip address spaces. The basic upshot of this is that these code snippets are
+executed atomically (because the kernel can't be pre-empted) and they may
+perform architecturally forbidden (to PL3) operations (like setting control
+registers).
+*/
+
+
 #include <asm/asm-offsets.h>
 #include <asm/unistd.h>
 #include <asm/errno.h>
@@ -15,6 +38,7 @@
 #include <asm/thread_info.h>
 #include <asm/assembly.h>
 #include <asm/processor.h>
+#include <asm/cache.h>
 
 #include <linux/linkage.h>
 
@@ -643,7 +667,7 @@ ENTRY(end_linux_gateway_page)
 
 	.section .rodata,"a"
 
-	.align PAGE_SIZE
+	.align 8
 	/* Light-weight-syscall table */
 	/* Start of lws table. */
 ENTRY(lws_table)
@@ -652,13 +676,13 @@ ENTRY(lws_table)
 END(lws_table)
 	/* End of lws table */
 
-	.align PAGE_SIZE
+	.align 8
 ENTRY(sys_call_table)
 #include "syscall_table.S"
 END(sys_call_table)
 
 #ifdef CONFIG_64BIT
-	.align PAGE_SIZE
+	.align 8
 ENTRY(sys_call_table64)
 #define SYSCALL_TABLE_64BIT
 #include "syscall_table.S"
@@ -674,7 +698,7 @@ END(sys_call_table64)
 		with ldcw.
 	*/
 	.section .data
-	.align	PAGE_SIZE
+	.align	L1_CACHE_BYTES
 ENTRY(lws_lock_start)
 	/* lws locks */
 	.rept 16
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index f702bff0bed9de6c6d5485e7f8ddc87a0ad76490..fe41a98043bbcf287e3ee3562972d6b693e140d0 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -522,10 +522,10 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 	 */
 	if (((unsigned long)regs->iaoq[0] & 3) &&
 	    ((unsigned long)regs->iasq[0] != (unsigned long)regs->sr[7])) { 
-	  	/* Kill the user process later */
-	  	regs->iaoq[0] = 0 | 3;
+		/* Kill the user process later */
+		regs->iaoq[0] = 0 | 3;
 		regs->iaoq[1] = regs->iaoq[0] + 4;
-	 	regs->iasq[0] = regs->iasq[1] = regs->sr[7];
+		regs->iasq[0] = regs->iasq[1] = regs->sr[7];
 		regs->gr[0] &= ~PSW_B;
 		return;
 	}
@@ -541,8 +541,8 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 		
 		/* set up a new led state on systems shipped with a LED State panel */
 		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_HPMC);
-		    
-	    	parisc_terminate("High Priority Machine Check (HPMC)",
+
+		parisc_terminate("High Priority Machine Check (HPMC)",
 				regs, code, 0);
 		/* NOT REACHED */
 		
@@ -584,13 +584,13 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 		/* Break instruction trap */
 		handle_break(regs);
 		return;
-	
+
 	case 10:
 		/* Privileged operation trap */
 		die_if_kernel("Privileged operation", regs, code);
 		si.si_code = ILL_PRVOPC;
 		goto give_sigill;
-	
+
 	case 11:
 		/* Privileged register trap */
 		if ((regs->iir & 0xffdfffe0) == 0x034008a0) {
@@ -634,7 +634,7 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 		if(user_mode(regs)){
 			si.si_signo = SIGFPE;
 			/* Set to zero, and let the userspace app figure it out from
-		   	   the insn pointed to by si_addr */
+			   the insn pointed to by si_addr */
 			si.si_code = 0;
 			si.si_addr = (void __user *) regs->iaoq[0];
 			force_sig_info(SIGFPE, &si, current);
@@ -648,7 +648,7 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 		die_if_kernel("Floating point exception", regs, 0); /* quiet */
 		handle_fpe(regs);
 		return;
-		
+
 	case 15:
 		/* Data TLB miss fault/Data page fault */
 		/* Fall through */
@@ -660,15 +660,15 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 	case 17:
 		/* Non-access data TLB miss fault/Non-access data page fault */
 		/* FIXME: 
-		 	 Still need to add slow path emulation code here!
-		         If the insn used a non-shadow register, then the tlb
+			 Still need to add slow path emulation code here!
+			 If the insn used a non-shadow register, then the tlb
 			 handlers could not have their side-effect (e.g. probe
 			 writing to a target register) emulated since rfir would
 			 erase the changes to said register. Instead we have to
 			 setup everything, call this function we are in, and emulate
 			 by hand. Technically we need to emulate:
 			 fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw
-		*/			  
+		*/
 		fault_address = regs->ior;
 		fault_space = regs->isr;
 		break;
diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S
index 64a999882e4fb8d0d584da223c7b1f43842e8d2c..4bb095a2f6fc2266388723cbb2634518a9570e44 100644
--- a/arch/parisc/kernel/vmlinux.lds.S
+++ b/arch/parisc/kernel/vmlinux.lds.S
@@ -95,7 +95,7 @@ SECTIONS
 	NOTES
 
 	/* Data */
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, PAGE_SIZE)
 
 	/* PA-RISC locks requires 16-byte alignment */
 	. = ALIGN(16);
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 157b931e7b09b89b60790b60aa016e5f5ac12913..ce939ac8622b84b7278f9e979e68a56354267adf 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -1069,6 +1069,7 @@ void flush_tlb_all(void)
 {
 	int do_recycle;
 
+	inc_irq_stat(irq_tlb_count);
 	do_recycle = 0;
 	spin_lock(&sid_lock);
 	if (dirty_space_ids > RECYCLE_THRESHOLD) {
@@ -1089,6 +1090,7 @@ void flush_tlb_all(void)
 #else
 void flush_tlb_all(void)
 {
+	inc_irq_stat(irq_tlb_count);
 	spin_lock(&sid_lock);
 	flush_tlb_all_local(NULL);
 	recycle_sids();
diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c
index 42cfcd9eb9aaeb3e8239e646a2634c4b23c54003..1ff1b67e8b274cc6869aab822694a1859954e132 100644
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -575,7 +575,7 @@ sba_io_pdir_entry(u64 *pdir_ptr, space_t sid, unsigned long vba,
 
 	mtsp(sid,1);
 	asm("lci 0(%%sr1, %1), %0" : "=r" (ci) : "r" (vba));
-	pa |= (ci >> 12) & 0xff;  /* move CI (8 bits) into lowest byte */
+	pa |= (ci >> PAGE_SHIFT) & 0xff;  /* move CI (8 bits) into lowest byte */
 
 	pa |= SBA_PDIR_VALID_BIT;	/* set "valid" bit */
 	*pdir_ptr = cpu_to_le64(pa);	/* swap and store into I/O Pdir */
@@ -1376,7 +1376,7 @@ static void
 sba_ioc_init(struct parisc_device *sba, struct ioc *ioc, int ioc_num)
 {
 	u32 iova_space_size, iova_space_mask;
-	unsigned int pdir_size, iov_order;
+	unsigned int pdir_size, iov_order, tcnfg;
 
 	/*
 	** Determine IOVA Space size from memory size.
@@ -1468,8 +1468,19 @@ sba_ioc_init(struct parisc_device *sba, struct ioc *ioc, int ioc_num)
 	WRITE_REG(ioc->ibase | 1, ioc->ioc_hpa+IOC_IBASE);
 	WRITE_REG(ioc->imask, ioc->ioc_hpa+IOC_IMASK);
 
-	/* Set I/O PDIR Page size to 4K */
-	WRITE_REG(0, ioc->ioc_hpa+IOC_TCNFG);
+	/* Set I/O PDIR Page size to system page size */
+	switch (PAGE_SHIFT) {
+		case 12: tcnfg = 0; break;	/*  4K */
+		case 13: tcnfg = 1; break;	/*  8K */
+		case 14: tcnfg = 2; break;	/* 16K */
+		case 16: tcnfg = 3; break;	/* 64K */
+		default:
+			panic(__FILE__ "Unsupported system page size %d",
+				1 << PAGE_SHIFT);
+			break;
+	}
+	/* Set I/O PDIR Page size to PAGE_SIZE (4k/16k/...) */
+	WRITE_REG(tcnfg, ioc->ioc_hpa+IOC_TCNFG);
 
 	/*
 	** Clear I/O TLB of any possible entries.