Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - a few misc things

 - kexec updates

 - DMA-mapping updates to better support networking DMA operations

 - IPC updates

 - various MM changes to improve DAX fault handling

 - lots of radix-tree changes, mainly to the test suite. All leading up
   to reimplementing the IDA/IDR code to be a wrapper layer over the
   radix-tree. However the final trigger-pulling patch is held off for
   4.11.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
  radix tree test suite: delete unused rcupdate.c
  radix tree test suite: add new tag check
  radix-tree: ensure counts are initialised
  radix tree test suite: cache recently freed objects
  radix tree test suite: add some more functionality
  idr: reduce the number of bits per level from 8 to 6
  rxrpc: abstract away knowledge of IDR internals
  tpm: use idr_find(), not idr_find_slowpath()
  idr: add ida_is_empty
  radix tree test suite: check multiorder iteration
  radix-tree: fix replacement for multiorder entries
  radix-tree: add radix_tree_split_preload()
  radix-tree: add radix_tree_split
  radix-tree: add radix_tree_join
  radix-tree: delete radix_tree_range_tag_if_tagged()
  radix-tree: delete radix_tree_locate_item()
  radix-tree: improve multiorder iterators
  btrfs: fix race in btrfs_free_dummy_fs_info()
  radix-tree: improve dump output
  radix-tree: make radix_tree_find_next_bit more useful
  ...

3 files changed, 47 insertions, 5 deletions

diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c
index 852a3291db96..9df997995f6b 100644
--- a/arch/sparc/kernel/iommu.c
+++ b/arch/sparc/kernel/iommu.c
@@ -415,7 +415,7 @@ static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr,
 		ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
 
 	/* Step 1: Kick data out of streaming buffers if necessary. */
-	if (strbuf->strbuf_enabled)
+	if (strbuf->strbuf_enabled && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		strbuf_flush(strbuf, iommu, bus_addr, ctx,
 			     npages, direction);
 
@@ -640,7 +640,7 @@ static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
 		base = iommu->page_table + entry;
 
 		dma_handle &= IO_PAGE_MASK;
-		if (strbuf->strbuf_enabled)
+		if (strbuf->strbuf_enabled && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 			strbuf_flush(strbuf, iommu, dma_handle, ctx,
 				     npages, direction);
 
diff --git a/arch/sparc/kernel/ioport.c b/arch/sparc/kernel/ioport.c
index 2344103414d1..6ffaec44931a 100644
--- a/arch/sparc/kernel/ioport.c
+++ b/arch/sparc/kernel/ioport.c
@@ -527,7 +527,7 @@ static dma_addr_t pci32_map_page(struct device *dev, struct page *page,
 static void pci32_unmap_page(struct device *dev, dma_addr_t ba, size_t size,
 			     enum dma_data_direction dir, unsigned long attrs)
 {
-	if (dir != PCI_DMA_TODEVICE)
+	if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		dma_make_coherent(ba, PAGE_ALIGN(size));
 }
 
@@ -572,7 +572,7 @@ static void pci32_unmap_sg(struct device *dev, struct scatterlist *sgl,
 	struct scatterlist *sg;
 	int n;
 
-	if (dir != PCI_DMA_TODEVICE) {
+	if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
 		for_each_sg(sgl, sg, nents, n) {
 			dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length));
 		}
diff --git a/arch/sparc/kernel/nmi.c b/arch/sparc/kernel/nmi.c
index a9973bb4a1b2..95e73c63c99d 100644
--- a/arch/sparc/kernel/nmi.c
+++ b/arch/sparc/kernel/nmi.c
@@ -42,7 +42,7 @@ static int panic_on_timeout;
  */
 atomic_t nmi_active = ATOMIC_INIT(0);		/* oprofile uses this */
 EXPORT_SYMBOL(nmi_active);
-
+static int nmi_init_done;
 static unsigned int nmi_hz = HZ;
 static DEFINE_PER_CPU(short, wd_enabled);
 static int endflag __initdata;
@@ -153,6 +153,8 @@ static void report_broken_nmi(int cpu, int *prev_nmi_count)
 
 void stop_nmi_watchdog(void *unused)
 {
+	if (!__this_cpu_read(wd_enabled))
+		return;
 	pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
 	__this_cpu_write(wd_enabled, 0);
 	atomic_dec(&nmi_active);
@@ -207,6 +209,9 @@ error:
 
 void start_nmi_watchdog(void *unused)
 {
+	if (__this_cpu_read(wd_enabled))
+		return;
+
 	__this_cpu_write(wd_enabled, 1);
 	atomic_inc(&nmi_active);
 
@@ -259,6 +264,8 @@ int __init nmi_init(void)
 		}
 	}
 
+	nmi_init_done = 1;
+
 	return err;
 }
 
@@ -270,3 +277,38 @@ static int __init setup_nmi_watchdog(char *str)
 	return 0;
 }
 __setup("nmi_watchdog=", setup_nmi_watchdog);
+
+/*
+ * sparc specific NMI watchdog enable function.
+ * Enables watchdog if it is not enabled already.
+ */
+int watchdog_nmi_enable(unsigned int cpu)
+{
+	if (atomic_read(&nmi_active) == -1) {
+		pr_warn("NMI watchdog cannot be enabled or disabled\n");
+		return -1;
+	}
+
+	/*
+	 * watchdog thread could start even before nmi_init is called.
+	 * Just Return in that case. Let nmi_init finish the init
+	 * process first.
+	 */
+	if (!nmi_init_done)
+		return 0;
+
+	smp_call_function_single(cpu, start_nmi_watchdog, NULL, 1);
+
+	return 0;
+}
+/*
+ * sparc specific NMI watchdog disable function.
+ * Disables watchdog if it is not disabled already.
+ */
+void watchdog_nmi_disable(unsigned int cpu)
+{
+	if (atomic_read(&nmi_active) == -1)
+		pr_warn_once("NMI watchdog cannot be enabled or disabled\n");
+	else
+		smp_call_function_single(cpu, stop_nmi_watchdog, NULL, 1);
+}