5 files changed, 34 insertions, 12 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index df7537f12469..c21941349b3e 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -419,28 +419,24 @@ config CPU_THUMBONLY
 config CPU_32v3
 	bool
 	select CPU_USE_DOMAINS if MMU
-	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
 	select NEED_KUSER_HELPERS
 	select TLS_REG_EMUL if SMP || !MMU
 
 config CPU_32v4
 	bool
 	select CPU_USE_DOMAINS if MMU
-	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
 	select NEED_KUSER_HELPERS
 	select TLS_REG_EMUL if SMP || !MMU
 
 config CPU_32v4T
 	bool
 	select CPU_USE_DOMAINS if MMU
-	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
 	select NEED_KUSER_HELPERS
 	select TLS_REG_EMUL if SMP || !MMU
 
 config CPU_32v5
 	bool
 	select CPU_USE_DOMAINS if MMU
-	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
 	select NEED_KUSER_HELPERS
 	select TLS_REG_EMUL if SMP || !MMU
 
@@ -805,14 +801,6 @@ config TLS_REG_EMUL
 	  a few prototypes like that in existence) and therefore access to
 	  that required register must be emulated.
 
-config NEEDS_SYSCALL_FOR_CMPXCHG
-	bool
-	select NEED_KUSER_HELPERS
-	help
-	  SMP on a pre-ARMv6 processor?  Well OK then.
-	  Forget about fast user space cmpxchg support.
-	  It is just not possible.
-
 config NEED_KUSER_HELPERS
 	bool
 
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 1a7815e5421b..ad4eb2d26e16 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1407,12 +1407,19 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
 	unsigned long uaddr = vma->vm_start;
 	unsigned long usize = vma->vm_end - vma->vm_start;
 	struct page **pages = __iommu_get_pages(cpu_addr, attrs);
+	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	unsigned long off = vma->vm_pgoff;
 
 	vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
 
 	if (!pages)
 		return -ENXIO;
 
+	if (off >= nr_pages || (usize >> PAGE_SHIFT) > nr_pages - off)
+		return -ENXIO;
+
+	pages += off;
+
 	do {
 		int ret = vm_insert_page(vma, uaddr, *pages++);
 		if (ret) {
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 0d629b8f973f..daafcf121ce0 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -593,6 +593,28 @@ do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)
 	arm_notify_die("", regs, &info, ifsr, 0);
 }
 
+/*
+ * Abort handler to be used only during first unmasking of asynchronous aborts
+ * on the boot CPU. This makes sure that the machine will not die if the
+ * firmware/bootloader left an imprecise abort pending for us to trip over.
+ */
+static int __init early_abort_handler(unsigned long addr, unsigned int fsr,
+				      struct pt_regs *regs)
+{
+	pr_warn("Hit pending asynchronous external abort (FSR=0x%08x) during "
+		"first unmask, this is most likely caused by a "
+		"firmware/bootloader bug.\n", fsr);
+
+	return 0;
+}
+
+void __init early_abt_enable(void)
+{
+	fsr_info[22].fn = early_abort_handler;
+	local_abt_enable();
+	fsr_info[22].fn = do_bad;
+}
+
 #ifndef CONFIG_ARM_LPAE
 static int __init exceptions_init(void)
 {
diff --git a/arch/arm/mm/fault.h b/arch/arm/mm/fault.h
index cf08bdfbe0d6..05ec5e0df32d 100644
--- a/arch/arm/mm/fault.h
+++ b/arch/arm/mm/fault.h
@@ -24,5 +24,6 @@ static inline int fsr_fs(unsigned int fsr)
 
 void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs);
 unsigned long search_exception_table(unsigned long addr);
+void early_abt_enable(void);
 
 #endif	/* __ARCH_ARM_FAULT_H */
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 7cd15143a507..4867f5daf82c 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -38,6 +38,7 @@
 #include <asm/mach/pci.h>
 #include <asm/fixmap.h>
 
+#include "fault.h"
 #include "mm.h"
 #include "tcm.h"
 
@@ -1363,6 +1364,9 @@ static void __init devicemaps_init(const struct machine_desc *mdesc)
 	 */
 	local_flush_tlb_all();
 	flush_cache_all();
+
+	/* Enable asynchronous aborts */
+	early_abt_enable();
 }
 
 static void __init kmap_init(void)