Merge branch 'parisc-for-3.10' of git://git.kernel.org/pub/scm/linux/…

…kernel/git/deller/parisc-linux

Pull parisc updates from Helge Deller:
 "Main fixes and updates in this patch series are:
   - we faced kernel stack corruptions because of multiple delivery of
     interrupts
   - added kernel stack overflow checks
   - added possibility to use dedicated stacks for irq processing
   - initial support for page sizes > 4k
   - more information in /proc/interrupts (e.g.  TLB flushes and number
     of IPI calls)
   - documented how the parisc gateway page works
   - and of course quite some other smaller cleanups and fixes."

* 'parisc-for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: tlb flush counting fix for SMP and UP
  parisc: more irq statistics in /proc/interrupts
  parisc: implement irq stacks
  parisc: add kernel stack overflow check
  parisc: only re-enable interrupts if we need to schedule or deliver signals when returning to userspace
  parisc: implement atomic64_dec_if_positive()
  parisc: use long branch in fork_like macro
  parisc: fix NATIVE set up in build
  parisc: document the parisc gateway page
  parisc: fix partly 16/64k PAGE_SIZE boot
  parisc: Provide default implementation for dma_{alloc, free}_attrs
  parisc: fix whitespace errors in arch/parisc/kernel/traps.c
  parisc: remove the second argument of kmap_atomic

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

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".

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

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 */
 
 

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)

arch/parisc/include/asm/hardirq.h

@@ -1,11 +1,41 @@
 /* hardirq.h: PA-RISC hard IRQ support.
  *
  * Copyright (C) 2001 Matthew Wilcox <[email protected]>
+ * Copyright (C) 2013 Helge Deller <[email protected]>
  */
 
 #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 */

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 */

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)

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()
  *

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);

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:
 	/*

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