Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Martin Schwidefsky:
 "Mostly cleanups and bug-fixes, with two exceptions.

  The first is lazy flushing of I/O-TLBs for PCI to improve performance,
  the second is software dirty bits in the pmd for the madvise-free
  implementation"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (24 commits)
  s390/locking: Reenable optimistic spinning
  s390/mm: implement dirty bits for large segment table entries
  KVM: s390/mm: Fix page table locking vs. split pmd lock
  s390/dasd: fix camel case
  s390/3215: fix hanging console issue
  s390/irq: improve displayed interrupt order in /proc/interrupts
  s390/seccomp: fix error return for filtered system calls
  s390/pci: introduce lazy IOTLB flushing for DMA unmap
  dasd: fix error recovery for alias devices during format
  dasd: fix list_del corruption during format
  dasd: fix unresponsive device during format
  dasd: use aliases for formatted devices during format
  s390/pci: fix kmsg component
  s390/kdump: Return NOTIFY_OK for all actions other than MEM_GOING_OFFLINE
  s390/watchdog: Fix module name in Kconfig help text
  s390/dasd: replace seq_printf by seq_puts
  s390/dasd: replace pr_warning by pr_warn
  s390/dasd: Move EXPORT_SYMBOL after function/variable
  s390/dasd: remove unnecessary null test before debugfs_remove
  s390/zfcp: use qdio buffer helpers
  ...

14 files changed, 266 insertions, 216 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 720a11d339eb..8ca60f8d5683 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -92,6 +92,7 @@ config S390
 	select ARCH_INLINE_WRITE_UNLOCK_IRQ
 	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
 	select ARCH_SAVE_PAGE_KEYS if HIBERNATION
+	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select BUILDTIME_EXTABLE_SORT
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index fcba5e03839f..b76317c1f3eb 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -287,7 +287,14 @@ extern unsigned long MODULES_END;
 #define _SEGMENT_ENTRY_INVALID	0x20	/* invalid segment table entry	    */
 #define _SEGMENT_ENTRY_COMMON	0x10	/* common segment bit		    */
 #define _SEGMENT_ENTRY_PTL	0x0f	/* page table length		    */
-#define _SEGMENT_ENTRY_NONE	_SEGMENT_ENTRY_PROTECT
+
+#define _SEGMENT_ENTRY_DIRTY	0	/* No sw dirty bit for 31-bit */
+#define _SEGMENT_ENTRY_YOUNG	0	/* No sw young bit for 31-bit */
+#define _SEGMENT_ENTRY_READ	0	/* No sw read bit for 31-bit */
+#define _SEGMENT_ENTRY_WRITE	0	/* No sw write bit for 31-bit */
+#define _SEGMENT_ENTRY_LARGE	0	/* No large pages for 31-bit */
+#define _SEGMENT_ENTRY_BITS_LARGE 0
+#define _SEGMENT_ENTRY_ORIGIN_LARGE 0
 
 #define _SEGMENT_ENTRY		(_SEGMENT_ENTRY_PTL)
 #define _SEGMENT_ENTRY_EMPTY	(_SEGMENT_ENTRY_INVALID)
@@ -350,7 +357,7 @@ extern unsigned long MODULES_END;
 
 /* Bits in the segment table entry */
 #define _SEGMENT_ENTRY_BITS	0xfffffffffffffe33UL
-#define _SEGMENT_ENTRY_BITS_LARGE 0xfffffffffff1ff33UL
+#define _SEGMENT_ENTRY_BITS_LARGE 0xfffffffffff0ff33UL
 #define _SEGMENT_ENTRY_ORIGIN_LARGE ~0xfffffUL /* large page address	    */
 #define _SEGMENT_ENTRY_ORIGIN	~0x7ffUL/* segment table origin		    */
 #define _SEGMENT_ENTRY_PROTECT	0x200	/* page protection bit		    */
@@ -359,30 +366,34 @@ extern unsigned long MODULES_END;
 #define _SEGMENT_ENTRY		(0)
 #define _SEGMENT_ENTRY_EMPTY	(_SEGMENT_ENTRY_INVALID)
 
-#define _SEGMENT_ENTRY_LARGE	0x400	/* STE-format control, large page   */
-#define _SEGMENT_ENTRY_CO	0x100	/* change-recording override   */
-#define _SEGMENT_ENTRY_SPLIT	0x001	/* THP splitting bit */
-#define _SEGMENT_ENTRY_YOUNG	0x002	/* SW segment young bit */
-#define _SEGMENT_ENTRY_NONE	_SEGMENT_ENTRY_YOUNG
+#define _SEGMENT_ENTRY_DIRTY	0x2000	/* SW segment dirty bit */
+#define _SEGMENT_ENTRY_YOUNG	0x1000	/* SW segment young bit */
+#define _SEGMENT_ENTRY_SPLIT	0x0800	/* THP splitting bit */
+#define _SEGMENT_ENTRY_LARGE	0x0400	/* STE-format control, large page */
+#define _SEGMENT_ENTRY_CO	0x0100	/* change-recording override   */
+#define _SEGMENT_ENTRY_READ	0x0002	/* SW segment read bit */
+#define _SEGMENT_ENTRY_WRITE	0x0001	/* SW segment write bit */
 
 /*
  * Segment table entry encoding (R = read-only, I = invalid, y = young bit):
- *			..R...I...y.
- * prot-none, old	..0...1...1.
- * prot-none, young	..1...1...1.
- * read-only, old	..1...1...0.
- * read-only, young	..1...0...1.
- * read-write, old	..0...1...0.
- * read-write, young	..0...0...1.
+ *				dy..R...I...wr
+ * prot-none, clean, old	00..1...1...00
+ * prot-none, clean, young	01..1...1...00
+ * prot-none, dirty, old	10..1...1...00
+ * prot-none, dirty, young	11..1...1...00
+ * read-only, clean, old	00..1...1...01
+ * read-only, clean, young	01..1...0...01
+ * read-only, dirty, old	10..1...1...01
+ * read-only, dirty, young	11..1...0...01
+ * read-write, clean, old	00..1...1...11
+ * read-write, clean, young	01..1...0...11
+ * read-write, dirty, old	10..0...1...11
+ * read-write, dirty, young	11..0...0...11
  * The segment table origin is used to distinguish empty (origin==0) from
  * read-write, old segment table entries (origin!=0)
  */
 
-#define _SEGMENT_ENTRY_SPLIT_BIT 0	/* THP splitting bit number */
-
-/* Set of bits not changed in pmd_modify */
-#define _SEGMENT_CHG_MASK	(_SEGMENT_ENTRY_ORIGIN | _SEGMENT_ENTRY_LARGE \
-				 | _SEGMENT_ENTRY_SPLIT | _SEGMENT_ENTRY_CO)
+#define _SEGMENT_ENTRY_SPLIT_BIT 11	/* THP splitting bit number */
 
 /* Page status table bits for virtualization */
 #define PGSTE_ACC_BITS	0xf000000000000000UL
@@ -455,10 +466,11 @@ extern unsigned long MODULES_END;
  * Segment entry (large page) protection definitions.
  */
 #define SEGMENT_NONE	__pgprot(_SEGMENT_ENTRY_INVALID | \
-				 _SEGMENT_ENTRY_NONE)
-#define SEGMENT_READ	__pgprot(_SEGMENT_ENTRY_INVALID | \
 				 _SEGMENT_ENTRY_PROTECT)
-#define SEGMENT_WRITE	__pgprot(_SEGMENT_ENTRY_INVALID)
+#define SEGMENT_READ	__pgprot(_SEGMENT_ENTRY_PROTECT | \
+				 _SEGMENT_ENTRY_READ)
+#define SEGMENT_WRITE	__pgprot(_SEGMENT_ENTRY_READ | \
+				 _SEGMENT_ENTRY_WRITE)
 
 static inline int mm_has_pgste(struct mm_struct *mm)
 {
@@ -569,25 +581,23 @@ static inline int pmd_none(pmd_t pmd)
 
 static inline int pmd_large(pmd_t pmd)
 {
-#ifdef CONFIG_64BIT
 	return (pmd_val(pmd) & _SEGMENT_ENTRY_LARGE) != 0;
-#else
-	return 0;
-#endif
 }
 
-static inline int pmd_prot_none(pmd_t pmd)
+static inline int pmd_pfn(pmd_t pmd)
 {
-	return (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) &&
-		(pmd_val(pmd) & _SEGMENT_ENTRY_NONE);
+	unsigned long origin_mask;
+
+	origin_mask = _SEGMENT_ENTRY_ORIGIN;
+	if (pmd_large(pmd))
+		origin_mask = _SEGMENT_ENTRY_ORIGIN_LARGE;
+	return (pmd_val(pmd) & origin_mask) >> PAGE_SHIFT;
 }
 
 static inline int pmd_bad(pmd_t pmd)
 {
-#ifdef CONFIG_64BIT
 	if (pmd_large(pmd))
 		return (pmd_val(pmd) & ~_SEGMENT_ENTRY_BITS_LARGE) != 0;
-#endif
 	return (pmd_val(pmd) & ~_SEGMENT_ENTRY_BITS) != 0;
 }
 
@@ -607,20 +617,22 @@ extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
 #define __HAVE_ARCH_PMD_WRITE
 static inline int pmd_write(pmd_t pmd)
 {
-	if (pmd_prot_none(pmd))
-		return 0;
-	return (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT) == 0;
+	return (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) != 0;
+}
+
+static inline int pmd_dirty(pmd_t pmd)
+{
+	int dirty = 1;
+	if (pmd_large(pmd))
+		dirty = (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) != 0;
+	return dirty;
 }
 
 static inline int pmd_young(pmd_t pmd)
 {
-	int young = 0;
-#ifdef CONFIG_64BIT
-	if (pmd_prot_none(pmd))
-		young = (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT) != 0;
-	else
+	int young = 1;
+	if (pmd_large(pmd))
 		young = (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) != 0;
-#endif
 	return young;
 }
 
@@ -1391,7 +1403,7 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
 #define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT)
 #define pte_page(x) pfn_to_page(pte_pfn(x))
 
-#define pmd_page(pmd) pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
+#define pmd_page(pmd) pfn_to_page(pmd_pfn(pmd))
 
 /* Find an entry in the lowest level page table.. */
 #define pte_offset(pmd, addr) ((pte_t *) pmd_deref(*(pmd)) + pte_index(addr))
@@ -1413,41 +1425,75 @@ static inline unsigned long massage_pgprot_pmd(pgprot_t pgprot)
 	return pgprot_val(SEGMENT_WRITE);
 }
 
-static inline pmd_t pmd_mkyoung(pmd_t pmd)
+static inline pmd_t pmd_wrprotect(pmd_t pmd)
 {
-#ifdef CONFIG_64BIT
-	if (pmd_prot_none(pmd)) {
+	pmd_val(pmd) &= ~_SEGMENT_ENTRY_WRITE;
+	pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
+	return pmd;
+}
+
+static inline pmd_t pmd_mkwrite(pmd_t pmd)
+{
+	pmd_val(pmd) |= _SEGMENT_ENTRY_WRITE;
+	if (pmd_large(pmd) && !(pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY))
+		return pmd;
+	pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT;
+	return pmd;
+}
+
+static inline pmd_t pmd_mkclean(pmd_t pmd)
+{
+	if (pmd_large(pmd)) {
+		pmd_val(pmd) &= ~_SEGMENT_ENTRY_DIRTY;
 		pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
-	} else {
+	}
+	return pmd;
+}
+
+static inline pmd_t pmd_mkdirty(pmd_t pmd)
+{
+	if (pmd_large(pmd)) {
+		pmd_val(pmd) |= _SEGMENT_ENTRY_DIRTY;
+		if (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE)
+			pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT;
+	}
+	return pmd;
+}
+
+static inline pmd_t pmd_mkyoung(pmd_t pmd)
+{
+	if (pmd_large(pmd)) {
 		pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG;
-		pmd_val(pmd) &= ~_SEGMENT_ENTRY_INVALID;
+		if (pmd_val(pmd) & _SEGMENT_ENTRY_READ)
+			pmd_val(pmd) &= ~_SEGMENT_ENTRY_INVALID;
 	}
-#endif
 	return pmd;
 }
 
 static inline pmd_t pmd_mkold(pmd_t pmd)
 {
-#ifdef CONFIG_64BIT
-	if (pmd_prot_none(pmd)) {
-		pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT;
-	} else {
+	if (pmd_large(pmd)) {
 		pmd_val(pmd) &= ~_SEGMENT_ENTRY_YOUNG;
 		pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID;
 	}
-#endif
 	return pmd;
 }
 
 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 {
-	int young;
-
-	young = pmd_young(pmd);
-	pmd_val(pmd) &= _SEGMENT_CHG_MASK;
+	if (pmd_large(pmd)) {
+		pmd_val(pmd) &= _SEGMENT_ENTRY_ORIGIN_LARGE |
+			_SEGMENT_ENTRY_DIRTY | _SEGMENT_ENTRY_YOUNG |
+			_SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_SPLIT;
+		pmd_val(pmd) |= massage_pgprot_pmd(newprot);
+		if (!(pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY))
+			pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
+		if (!(pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG))
+			pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID;
+		return pmd;
+	}
+	pmd_val(pmd) &= _SEGMENT_ENTRY_ORIGIN;
 	pmd_val(pmd) |= massage_pgprot_pmd(newprot);
-	if (young)
-		pmd = pmd_mkyoung(pmd);
 	return pmd;
 }
 
@@ -1455,16 +1501,9 @@ static inline pmd_t mk_pmd_phys(unsigned long physpage, pgprot_t pgprot)
 {
 	pmd_t __pmd;
 	pmd_val(__pmd) = physpage + massage_pgprot_pmd(pgprot);
-	return pmd_mkyoung(__pmd);
+	return __pmd;
 }
 
-static inline pmd_t pmd_mkwrite(pmd_t pmd)
-{
-	/* Do not clobber PROT_NONE segments! */
-	if (!pmd_prot_none(pmd))
-		pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT;
-	return pmd;
-}
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLB_PAGE */
 
 static inline void __pmdp_csp(pmd_t *pmdp)
@@ -1555,34 +1594,21 @@ extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
 
 static inline int pmd_trans_splitting(pmd_t pmd)
 {
-	return pmd_val(pmd) & _SEGMENT_ENTRY_SPLIT;
+	return (pmd_val(pmd) & _SEGMENT_ENTRY_LARGE) &&
+		(pmd_val(pmd) & _SEGMENT_ENTRY_SPLIT);
 }
 
 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 			      pmd_t *pmdp, pmd_t entry)
 {
-	if (!(pmd_val(entry) & _SEGMENT_ENTRY_INVALID) && MACHINE_HAS_EDAT1)
-		pmd_val(entry) |= _SEGMENT_ENTRY_CO;
 	*pmdp = entry;
 }
 
 static inline pmd_t pmd_mkhuge(pmd_t pmd)
 {
 	pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
-	return pmd;
-}
-
-static inline pmd_t pmd_wrprotect(pmd_t pmd)
-{
-	/* Do not clobber PROT_NONE segments! */
-	if (!pmd_prot_none(pmd))
-		pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
-	return pmd;
-}
-
-static inline pmd_t pmd_mkdirty(pmd_t pmd)
-{
-	/* No dirty bit in the segment table entry. */
+	pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG;
+	pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
 	return pmd;
 }
 
@@ -1647,11 +1673,6 @@ static inline int has_transparent_hugepage(void)
 {
 	return MACHINE_HAS_HPAGE ? 1 : 0;
 }
-
-static inline unsigned long pmd_pfn(pmd_t pmd)
-{
-	return pmd_val(pmd) >> PAGE_SHIFT;
-}
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 /*
diff --git a/arch/s390/include/asm/qdio.h b/arch/s390/include/asm/qdio.h
index d786c634e052..06f3034605a1 100644
--- a/arch/s390/include/asm/qdio.h
+++ b/arch/s390/include/asm/qdio.h
@@ -415,6 +415,10 @@ struct qdio_brinfo_entry_l2 {
 #define QDIO_FLAG_SYNC_OUTPUT		0x02
 #define QDIO_FLAG_PCI_OUT		0x10
 
+int qdio_alloc_buffers(struct qdio_buffer **buf, unsigned int count);
+void qdio_free_buffers(struct qdio_buffer **buf, unsigned int count);
+void qdio_reset_buffers(struct qdio_buffer **buf, unsigned int count);
+
 extern int qdio_allocate(struct qdio_initialize *);
 extern int qdio_establish(struct qdio_initialize *);
 extern int qdio_activate(struct ccw_device *);
diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
index abad78d5b10c..5bc12598ae9e 100644
--- a/arch/s390/include/asm/syscall.h
+++ b/arch/s390/include/asm/syscall.h
@@ -54,7 +54,7 @@ static inline void syscall_set_return_value(struct task_struct *task,
 					    struct pt_regs *regs,
 					    int error, long val)
 {
-	regs->gprs[2] = error ? -error : val;
+	regs->gprs[2] = error ? error : val;
 }
 
 static inline void syscall_get_arguments(struct task_struct *task,
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 99b0b09646ca..8eb82443cfbd 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -30,6 +30,7 @@ DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
 EXPORT_PER_CPU_SYMBOL_GPL(irq_stat);
 
 struct irq_class {
+	int irq;
 	char *name;
 	char *desc;
 };
@@ -45,9 +46,9 @@ struct irq_class {
  * up with having a sum which accounts each interrupt twice.
  */
 static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = {
-	[EXT_INTERRUPT]  = {.name = "EXT"},
-	[IO_INTERRUPT]	 = {.name = "I/O"},
-	[THIN_INTERRUPT] = {.name = "AIO"},
+	{.irq = EXT_INTERRUPT,	.name = "EXT"},
+	{.irq = IO_INTERRUPT,	.name = "I/O"},
+	{.irq = THIN_INTERRUPT, .name = "AIO"},
 };
 
 /*
@@ -56,38 +57,38 @@ static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = {
  * In addition this list contains non external / I/O events like NMIs.
  */
 static const struct irq_class irqclass_sub_desc[NR_ARCH_IRQS] = {
-	[IRQEXT_CLK] = {.name = "CLK", .desc = "[EXT] Clock Comparator"},
-	[IRQEXT_EXC] = {.name = "EXC", .desc = "[EXT] External Call"},
-	[IRQEXT_EMS] = {.name = "EMS", .desc = "[EXT] Emergency Signal"},
-	[IRQEXT_TMR] = {.name = "TMR", .desc = "[EXT] CPU Timer"},
-	[IRQEXT_TLA] = {.name = "TAL", .desc = "[EXT] Timing Alert"},
-	[IRQEXT_PFL] = {.name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
-	[IRQEXT_DSD] = {.name = "DSD", .desc = "[EXT] DASD Diag"},
-	[IRQEXT_VRT] = {.name = "VRT", .desc = "[EXT] Virtio"},
-	[IRQEXT_SCP] = {.name = "SCP", .desc = "[EXT] Service Call"},
-	[IRQEXT_IUC] = {.name = "IUC", .desc = "[EXT] IUCV"},
-	[IRQEXT_CMS] = {.name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
-	[IRQEXT_CMC] = {.name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
-	[IRQEXT_CMR] = {.name = "CMR", .desc = "[EXT] CPU-Measurement: RI"},
-	[IRQIO_CIO]  = {.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
-	[IRQIO_QAI]  = {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt"},
-	[IRQIO_DAS]  = {.name = "DAS", .desc = "[I/O] DASD"},
-	[IRQIO_C15]  = {.name = "C15", .desc = "[I/O] 3215"},
-	[IRQIO_C70]  = {.name = "C70", .desc = "[I/O] 3270"},
-	[IRQIO_TAP]  = {.name = "TAP", .desc = "[I/O] Tape"},
-	[IRQIO_VMR]  = {.name = "VMR", .desc = "[I/O] Unit Record Devices"},
-	[IRQIO_LCS]  = {.name = "LCS", .desc = "[I/O] LCS"},
-	[IRQIO_CLW]  = {.name = "CLW", .desc = "[I/O] CLAW"},
-	[IRQIO_CTC]  = {.name = "CTC", .desc = "[I/O] CTC"},
-	[IRQIO_APB]  = {.name = "APB", .desc = "[I/O] AP Bus"},
-	[IRQIO_ADM]  = {.name = "ADM", .desc = "[I/O] EADM Subchannel"},
-	[IRQIO_CSC]  = {.name = "CSC", .desc = "[I/O] CHSC Subchannel"},
-	[IRQIO_PCI]  = {.name = "PCI", .desc = "[I/O] PCI Interrupt" },
-	[IRQIO_MSI]  = {.name = "MSI", .desc = "[I/O] MSI Interrupt" },
-	[IRQIO_VIR]  = {.name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
-	[IRQIO_VAI]  = {.name = "VAI", .desc = "[I/O] Virtual I/O Devices AI"},
-	[NMI_NMI]    = {.name = "NMI", .desc = "[NMI] Machine Check"},
-	[CPU_RST]    = {.name = "RST", .desc = "[CPU] CPU Restart"},
+	{.irq = IRQEXT_CLK, .name = "CLK", .desc = "[EXT] Clock Comparator"},
+	{.irq = IRQEXT_EXC, .name = "EXC", .desc = "[EXT] External Call"},
+	{.irq = IRQEXT_EMS, .name = "EMS", .desc = "[EXT] Emergency Signal"},
+	{.irq = IRQEXT_TMR, .name = "TMR", .desc = "[EXT] CPU Timer"},
+	{.irq = IRQEXT_TLA, .name = "TAL", .desc = "[EXT] Timing Alert"},
+	{.irq = IRQEXT_PFL, .name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
+	{.irq = IRQEXT_DSD, .name = "DSD", .desc = "[EXT] DASD Diag"},
+	{.irq = IRQEXT_VRT, .name = "VRT", .desc = "[EXT] Virtio"},
+	{.irq = IRQEXT_SCP, .name = "SCP", .desc = "[EXT] Service Call"},
+	{.irq = IRQEXT_IUC, .name = "IUC", .desc = "[EXT] IUCV"},
+	{.irq = IRQEXT_CMS, .name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
+	{.irq = IRQEXT_CMC, .name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
+	{.irq = IRQEXT_CMR, .name = "CMR", .desc = "[EXT] CPU-Measurement: RI"},
+	{.irq = IRQIO_CIO,  .name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
+	{.irq = IRQIO_QAI,  .name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt"},
+	{.irq = IRQIO_DAS,  .name = "DAS", .desc = "[I/O] DASD"},
+	{.irq = IRQIO_C15,  .name = "C15", .desc = "[I/O] 3215"},
+	{.irq = IRQIO_C70,  .name = "C70", .desc = "[I/O] 3270"},
+	{.irq = IRQIO_TAP,  .name = "TAP", .desc = "[I/O] Tape"},
+	{.irq = IRQIO_VMR,  .name = "VMR", .desc = "[I/O] Unit Record Devices"},
+	{.irq = IRQIO_LCS,  .name = "LCS", .desc = "[I/O] LCS"},
+	{.irq = IRQIO_CLW,  .name = "CLW", .desc = "[I/O] CLAW"},
+	{.irq = IRQIO_CTC,  .name = "CTC", .desc = "[I/O] CTC"},
+	{.irq = IRQIO_APB,  .name = "APB", .desc = "[I/O] AP Bus"},
+	{.irq = IRQIO_ADM,  .name = "ADM", .desc = "[I/O] EADM Subchannel"},
+	{.irq = IRQIO_CSC,  .name = "CSC", .desc = "[I/O] CHSC Subchannel"},
+	{.irq = IRQIO_PCI,  .name = "PCI", .desc = "[I/O] PCI Interrupt" },
+	{.irq = IRQIO_MSI,  .name = "MSI", .desc = "[I/O] MSI Interrupt" },
+	{.irq = IRQIO_VIR,  .name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
+	{.irq = IRQIO_VAI,  .name = "VAI", .desc = "[I/O] Virtual I/O Devices AI"},
+	{.irq = NMI_NMI,    .name = "NMI", .desc = "[NMI] Machine Check"},
+	{.irq = CPU_RST,    .name = "RST", .desc = "[CPU] CPU Restart"},
 };
 
 void __init init_IRQ(void)
@@ -116,33 +117,37 @@ void do_IRQ(struct pt_regs *regs, int irq)
  */
 int show_interrupts(struct seq_file *p, void *v)
 {
-	int irq = *(loff_t *) v;
-	int cpu;
+	int index = *(loff_t *) v;
+	int cpu, irq;
 
 	get_online_cpus();
-	if (irq == 0) {
+	if (index == 0) {
 		seq_puts(p, "           ");
 		for_each_online_cpu(cpu)
 			seq_printf(p, "CPU%d       ", cpu);
 		seq_putc(p, '\n');
 		goto out;
 	}
-	if (irq < NR_IRQS) {
-		if (irq >= NR_IRQS_BASE)
+	if (index < NR_IRQS) {
+		if (index >= NR_IRQS_BASE)
 			goto out;
-		seq_printf(p, "%s: ", irqclass_main_desc[irq].name);
+		/* Adjust index to process irqclass_main_desc array entries */
+		index--;
+		seq_printf(p, "%s: ", irqclass_main_desc[index].name);
+		irq = irqclass_main_desc[index].irq;
 		for_each_online_cpu(cpu)
 			seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
 		seq_putc(p, '\n');
 		goto out;
 	}
-	for (irq = 0; irq < NR_ARCH_IRQS; irq++) {
-		seq_printf(p, "%s: ", irqclass_sub_desc[irq].name);
+	for (index = 0; index < NR_ARCH_IRQS; index++) {
+		seq_printf(p, "%s: ", irqclass_sub_desc[index].name);
+		irq = irqclass_sub_desc[index].irq;
 		for_each_online_cpu(cpu)
 			seq_printf(p, "%10u ",
 				   per_cpu(irq_stat, cpu).irqs[irq]);
-		if (irqclass_sub_desc[irq].desc)
-			seq_printf(p, "  %s", irqclass_sub_desc[irq].desc);
+		if (irqclass_sub_desc[index].desc)
+			seq_printf(p, "  %s", irqclass_sub_desc[index].desc);
 		seq_putc(p, '\n');
 	}
 out:
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 1e2264b46e4c..ae1d5be7dd88 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -501,6 +501,8 @@ static int kdump_mem_notifier(struct notifier_block *nb,
 {
 	struct memory_notify *arg = data;
 
+	if (action != MEM_GOING_OFFLINE)
+		return NOTIFY_OK;
 	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
 		return NOTIFY_BAD;
 	if (arg->start_pfn > PFN_DOWN(crashk_res.end))
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index 0ff66a7e29bb..389bc17934b7 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -10,42 +10,33 @@
 
 static inline pmd_t __pte_to_pmd(pte_t pte)
 {
-	int none, young, prot;
 	pmd_t pmd;
 
 	/*
-	 * Convert encoding		  pte bits	  pmd bits
-	 *				.IR...wrdytp	..R...I...y.
-	 * empty			.10...000000 -> ..0...1...0.
-	 * prot-none, clean, old	.11...000001 -> ..0...1...1.
-	 * prot-none, clean, young	.11...000101 -> ..1...1...1.
-	 * prot-none, dirty, old	.10...001001 -> ..0...1...1.
-	 * prot-none, dirty, young	.10...001101 -> ..1...1...1.
-	 * read-only, clean, old	.11...010001 -> ..1...1...0.
-	 * read-only, clean, young	.01...010101 -> ..1...0...1.
-	 * read-only, dirty, old	.11...011001 -> ..1...1...0.
-	 * read-only, dirty, young	.01...011101 -> ..1...0...1.
-	 * read-write, clean, old	.11...110001 -> ..0...1...0.
-	 * read-write, clean, young	.01...110101 -> ..0...0...1.
-	 * read-write, dirty, old	.10...111001 -> ..0...1...0.
-	 * read-write, dirty, young	.00...111101 -> ..0...0...1.
-	 * Huge ptes are dirty by definition, a clean pte is made dirty
-	 * by the conversion.
+	 * Convert encoding		  pte bits	   pmd bits
+	 *				.IR...wrdytp	dy..R...I...wr
+	 * empty			.10...000000 -> 00..0...1...00
+	 * prot-none, clean, old	.11...000001 -> 00..1...1...00
+	 * prot-none, clean, young	.11...000101 -> 01..1...1...00
+	 * prot-none, dirty, old	.10...001001 -> 10..1...1...00
+	 * prot-none, dirty, young	.10...001101 -> 11..1...1...00
+	 * read-only, clean, old	.11...010001 -> 00..1...1...01
+	 * read-only, clean, young	.01...010101 -> 01..1...0...01
+	 * read-only, dirty, old	.11...011001 -> 10..1...1...01
+	 * read-only, dirty, young	.01...011101 -> 11..1...0...01
+	 * read-write, clean, old	.11...110001 -> 00..0...1...11
+	 * read-write, clean, young	.01...110101 -> 01..0...0...11
+	 * read-write, dirty, old	.10...111001 -> 10..0...1...11
+	 * read-write, dirty, young	.00...111101 -> 11..0...0...11
 	 */
 	if (pte_present(pte)) {
 		pmd_val(pmd) = pte_val(pte) & PAGE_MASK;
-		if (pte_val(pte) & _PAGE_INVALID)
-			pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID;
-		none = (pte_val(pte) & _PAGE_PRESENT) &&
-			!(pte_val(pte) & _PAGE_READ) &&
-			!(pte_val(pte) & _PAGE_WRITE);
-		prot = (pte_val(pte) & _PAGE_PROTECT) &&
-			!(pte_val(pte) & _PAGE_WRITE);
-		young = pte_val(pte) & _PAGE_YOUNG;
-		if (none || young)
-			pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG;
-		if (prot || (none && young))
-			pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
+		pmd_val(pmd) |= (pte_val(pte) & _PAGE_READ) >> 4;
+		pmd_val(pmd) |= (pte_val(pte) & _PAGE_WRITE) >> 4;
+		pmd_val(pmd) |=	(pte_val(pte) & _PAGE_INVALID) >> 5;
+		pmd_val(pmd) |= (pte_val(pte) & _PAGE_PROTECT);
+		pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10;
+		pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10;
 	} else
 		pmd_val(pmd) = _SEGMENT_ENTRY_INVALID;
 	return pmd;
@@ -56,34 +47,31 @@ static inline pte_t __pmd_to_pte(pmd_t pmd)
 	pte_t pte;
 
 	/*
-	 * Convert encoding	  pmd bits	  pte bits
-	 *			..R...I...y.	.IR...wrdytp
-	 * empty		..0...1...0. -> .10...000000
-	 * prot-none, old	..0...1...1. -> .10...001001
-	 * prot-none, young	..1...1...1. -> .10...001101
-	 * read-only, old	..1...1...0. -> .11...011001
-	 * read-only, young	..1...0...1. -> .01...011101
-	 * read-write, old	..0...1...0. -> .10...111001
-	 * read-write, young	..0...0...1. -> .00...111101
-	 * Huge ptes are dirty by definition
+	 * Convert encoding		   pmd bits	    pte bits
+	 *				dy..R...I...wr	  .IR...wrdytp
+	 * empty			00..0...1...00 -> .10...001100
+	 * prot-none, clean, old	00..0...1...00 -> .10...000001
+	 * prot-none, clean, young	01..0...1...00 -> .10...000101
+	 * prot-none, dirty, old	10..0...1...00 -> .10...001001
+	 * prot-none, dirty, young	11..0...1...00 -> .10...001101
+	 * read-only, clean, old	00..1...1...01 -> .11...010001
+	 * read-only, clean, young	01..1...1...01 -> .11...010101
+	 * read-only, dirty, old	10..1...1...01 -> .11...011001
+	 * read-only, dirty, young	11..1...1...01 -> .11...011101
+	 * read-write, clean, old	00..0...1...11 -> .10...110001
+	 * read-write, clean, young	01..0...1...11 -> .10...110101
+	 * read-write, dirty, old	10..0...1...11 -> .10...111001
+	 * read-write, dirty, young	11..0...1...11 -> .10...111101
 	 */
 	if (pmd_present(pmd)) {
-		pte_val(pte) = _PAGE_PRESENT | _PAGE_LARGE | _PAGE_DIRTY |
-			(pmd_val(pmd) & PAGE_MASK);
-		if (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID)
-			pte_val(pte) |= _PAGE_INVALID;
-		if (pmd_prot_none(pmd)) {
-			if (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT)
-				pte_val(pte) |= _PAGE_YOUNG;
-		} else {
-			pte_val(pte) |= _PAGE_READ;
-			if (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT)
-				pte_val(pte) |= _PAGE_PROTECT;
-			else
-				pte_val(pte) |= _PAGE_WRITE;
-			if (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG)
-				pte_val(pte) |= _PAGE_YOUNG;
-		}
+		pte_val(pte) = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN_LARGE;
+		pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
+		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_READ) << 4;
+		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) << 4;
+		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) << 5;
+		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT);
+		pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10;
+		pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10;
 	} else
 		pte_val(pte) = _PAGE_INVALID;
 	return pte;
@@ -96,6 +84,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 
 	pmd = __pte_to_pmd(pte);
 	if (!MACHINE_HAS_HPAGE) {
+		/* Emulated huge ptes loose the dirty and young bit */
 		pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN;
 		pmd_val(pmd) |= pte_page(pte)[1].index;
 	} else
@@ -113,6 +102,8 @@ pte_t huge_ptep_get(pte_t *ptep)
 		origin = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN;
 		pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN;
 		pmd_val(pmd) |= *(unsigned long *) origin;
+		/* Emulated huge ptes are young and dirty by definition */
+		pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG | _SEGMENT_ENTRY_DIRTY;
 	}
 	return __pmd_to_pte(pmd);
 }
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 37b8241ec784..19daa53a3da4 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -1279,6 +1279,7 @@ static unsigned long page_table_realloc_pmd(struct mmu_gather *tlb,
 {
 	unsigned long next, *table, *new;
 	struct page *page;
+	spinlock_t *ptl;
 	pmd_t *pmd;
 
 	pmd = pmd_offset(pud, addr);
@@ -1296,7 +1297,7 @@ again:
 		if (!new)
 			return -ENOMEM;
 
-		spin_lock(&mm->page_table_lock);
+		ptl = pmd_lock(mm, pmd);
 		if (likely((unsigned long *) pmd_deref(*pmd) == table)) {
 			/* Nuke pmd entry pointing to the "short" page table */
 			pmdp_flush_lazy(mm, addr, pmd);
@@ -1310,7 +1311,7 @@ again:
 			page_table_free_rcu(tlb, table);
 			new = NULL;
 		}
-		spin_unlock(&mm->page_table_lock);
+		spin_unlock(ptl);
 		if (new) {
 			page_table_free_pgste(new);
 			goto again;
@@ -1432,6 +1433,9 @@ int pmdp_set_access_flags(struct vm_area_struct *vma,
 {
 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 
+	entry = pmd_mkyoung(entry);
+	if (dirty)
+		entry = pmd_mkdirty(entry);
 	if (pmd_same(*pmdp, entry))
 		return 0;
 	pmdp_invalidate(vma, address, pmdp);
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 30de42730b2f..2fa7b14b9c08 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -15,8 +15,8 @@
  *   Thomas Klein
  */
 
-#define COMPONENT "zPCI"
-#define pr_fmt(fmt) COMPONENT ": " fmt
+#define KMSG_COMPONENT "zpci"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/kernel.h>
 #include <linux/slab.h>
diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index 96545d7659fd..6e22a247de9b 100644
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -5,8 +5,8 @@
  *   Jan Glauber <jang@linux.vnet.ibm.com>
  */
 
-#define COMPONENT "zPCI"
-#define pr_fmt(fmt) COMPONENT ": " fmt
+#define KMSG_COMPONENT "zpci"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/kernel.h>
 #include <linux/slab.h>
diff --git a/arch/s390/pci/pci_debug.c b/arch/s390/pci/pci_debug.c
index c5c66840ac00..eec598c5939f 100644
--- a/arch/s390/pci/pci_debug.c
+++ b/arch/s390/pci/pci_debug.c
@@ -5,8 +5,8 @@
  *    Jan Glauber <jang@linux.vnet.ibm.com>
  */
 
-#define COMPONENT "zPCI"
-#define pr_fmt(fmt) COMPONENT ": " fmt
+#define KMSG_COMPONENT "zpci"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/kernel.h>
 #include <linux/seq_file.h>
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index f91c03119804..4cbb29a4d615 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -16,6 +16,13 @@
 
 static struct kmem_cache *dma_region_table_cache;
 static struct kmem_cache *dma_page_table_cache;
+static int s390_iommu_strict;
+
+static int zpci_refresh_global(struct zpci_dev *zdev)
+{
+	return zpci_refresh_trans((u64) zdev->fh << 32, zdev->start_dma,
+				  zdev->iommu_pages * PAGE_SIZE);
+}
 
 static unsigned long *dma_alloc_cpu_table(void)
 {
@@ -155,18 +162,15 @@ static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
 	}
 
 	/*
-	 * rpcit is not required to establish new translations when previously
-	 * invalid translation-table entries are validated, however it is
-	 * required when altering previously valid entries.
+	 * With zdev->tlb_refresh == 0, rpcit is not required to establish new
+	 * translations when previously invalid translation-table entries are
+	 * validated. With lazy unmap, it also is skipped for previously valid
+	 * entries, but a global rpcit is then required before any address can
+	 * be re-used, i.e. after each iommu bitmap wrap-around.
 	 */
 	if (!zdev->tlb_refresh &&
-	    ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))
-		/*
-		 * TODO: also need to check that the old entry is indeed INVALID
-		 * and not only for one page but for the whole range...
-		 * -> now we WARN_ON in that case but with lazy unmap that
-		 * needs to be redone!
-		 */
+			(!s390_iommu_strict ||
+			((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)))
 		goto no_refresh;
 
 	rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
@@ -220,16 +224,21 @@ static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev,
 static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size)
 {
 	unsigned long offset, flags;
+	int wrap = 0;
 
 	spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
 	offset = __dma_alloc_iommu(zdev, zdev->next_bit, size);
-	if (offset == -1)
+	if (offset == -1) {
+		/* wrap-around */
 		offset = __dma_alloc_iommu(zdev, 0, size);
+		wrap = 1;
+	}
 
 	if (offset != -1) {
 		zdev->next_bit = offset + size;
-		if (zdev->next_bit >= zdev->iommu_pages)
-			zdev->next_bit = 0;
+		if (!zdev->tlb_refresh && !s390_iommu_strict && wrap)
+			/* global flush after wrap-around with lazy unmap */
+			zpci_refresh_global(zdev);
 	}
 	spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 	return offset;
@@ -243,7 +252,11 @@ static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size
 	if (!zdev->iommu_bitmap)
 		goto out;
 	bitmap_clear(zdev->iommu_bitmap, offset, size);
-	if (offset >= zdev->next_bit)
+	/*
+	 * Lazy flush for unmap: need to move next_bit to avoid address re-use
+	 * until wrap-around.
+	 */
+	if (!s390_iommu_strict && offset >= zdev->next_bit)
 		zdev->next_bit = offset + size;
 out:
 	spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
@@ -504,3 +517,12 @@ struct dma_map_ops s390_dma_ops = {
 	/* dma_supported is unconditionally true without a callback */
 };
 EXPORT_SYMBOL_GPL(s390_dma_ops);
+
+static int __init s390_iommu_setup(char *str)
+{
+	if (!strncmp(str, "strict", 6))
+		s390_iommu_strict = 1;
+	return 0;
+}
+
+__setup("s390_iommu=", s390_iommu_setup);
diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
index 6d7f5a3016ca..460fdb21cf61 100644
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -5,8 +5,8 @@
  *    Jan Glauber <jang@linux.vnet.ibm.com>
  */
 
-#define COMPONENT "zPCI"
-#define pr_fmt(fmt) COMPONENT ": " fmt
+#define KMSG_COMPONENT "zpci"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/kernel.h>
 #include <linux/pci.h>
diff --git a/arch/s390/pci/pci_sysfs.c b/arch/s390/pci/pci_sysfs.c
index 9190214b8702..fa3ce891e597 100644
--- a/arch/s390/pci/pci_sysfs.c
+++ b/arch/s390/pci/pci_sysfs.c
@@ -5,8 +5,8 @@
  *   Jan Glauber <jang@linux.vnet.ibm.com>
  */
 
-#define COMPONENT "zPCI"
-#define pr_fmt(fmt) COMPONENT ": " fmt
+#define KMSG_COMPONENT "zpci"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/kernel.h>
 #include <linux/stat.h>