Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

Pull ARM updates from Russell King:
 "In this ARM merge, we remove more lines than we add.  Changes include:

   - Enable imprecise aborts early, so that bus errors aren't masked
     until later in the boot.  This has the side effect that boot
     loaders which provoke these aborts can cause the kernel to crash
     early in boot, so we install a handler to report this event around
     the site where these are enabled.

   - Remove the buggy but impossible to enable cmpxchg syscall code.

   - Add unwinding annotations to some assembly code.

   - Add support for atomic half-word exchange for ARMv6k+.

   - Reduce ioremap() alignment for SMP/LPAE cases where we don't need
     the large alignment.

   - Addition of an "optimal" 3G configuration for systems with 1G of
     RAM.

   - Increase vmalloc space by 128M.

   - Constify some SMP operations structures, which have never been
     writable.

   - Improve ARMs dma_mmap() support for mapping DMA coherent mappings
     into userspace.

   - Fix to the NMI backtrace code in the IPI case on ARM where the
     failing CPU gets stuck for 10s waiting for its own IPI to be
     delivered.

   - Removal of legacy PM support from the AMBA bus driver.

   - Another fix for the previous fix of vdsomunge"

* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (23 commits)
  ARM: 8449/1: fix bug in vdsomunge swab32 macro
  arm: add missing of_node_put
  ARM: 8447/1: catch pending imprecise abort on unmask
  ARM: 8446/1: amba: Remove unused callbacks for legacy system PM
  ARM: 8443/1: Adding support for atomic half word exchange
  ARM: clean up TWD after previous patch
  ARM: 8441/2: twd: Don't set CLOCK_EVT_FEAT_C3STOP unconditionally
  ARM: 8440/1: remove obsolete documentation
  ARM: make highpte an expert option
  ARM: 8433/1: add a VMSPLIT_3G_OPT config option
  ARM: 8439/1: Fix backtrace generation when IPI is masked
  ARM: 8428/1: kgdb: Fix registers on sleeping tasks
  ARM: 8427/1: dma-mapping: add support for offset parameter in dma_mmap()
  ARM: 8426/1: dma-mapping: add missing range check in dma_mmap()
  ARM: remove user cmpxchg syscall
  ARM: 8438/1: Add unwinding to __clear_user_std()
  ARM: 8436/1: hw_breakpoint: remove unnecessary header
  ARM: 8434/2: Revert "7655/1: smp_twd: make twd_local_timer_of_register() no-op for nosmp"
  ARM: 8432/1: move VMALLOC_END from 0xff000000 to 0xff800000
  ARM: 8430/1: use default ioremap alignment for SMP or LPAE
  ...

7 files changed, 40 insertions, 112 deletions

diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index 11c54de9f8cf..65addcbf5b30 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -101,6 +101,7 @@ void __init arm_dt_init_cpu_maps(void)
 		if (of_property_read_u32(cpu, "reg", &hwid)) {
 			pr_debug(" * %s missing reg property\n",
 				     cpu->full_name);
+			of_node_put(cpu);
 			return;
 		}
 
@@ -108,8 +109,10 @@ void __init arm_dt_init_cpu_maps(void)
 		 * 8 MSBs must be set to 0 in the DT since the reg property
 		 * defines the MPIDR[23:0].
 		 */
-		if (hwid & ~MPIDR_HWID_BITMASK)
+		if (hwid & ~MPIDR_HWID_BITMASK) {
+			of_node_put(cpu);
 			return;
+		}
 
 		/*
 		 * Duplicate MPIDRs are a recipe for disaster.
@@ -119,9 +122,11 @@ void __init arm_dt_init_cpu_maps(void)
 		 * to avoid matching valid MPIDR[23:0] values.
 		 */
 		for (j = 0; j < cpuidx; j++)
-			if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg "
-						     "properties in the DT\n"))
+			if (WARN(tmp_map[j] == hwid,
+				 "Duplicate /cpu reg properties in the DT\n")) {
+				of_node_put(cpu);
 				return;
+			}
 
 		/*
 		 * Build a stashed array of MPIDR values. Numbering scheme
@@ -143,6 +148,7 @@ void __init arm_dt_init_cpu_maps(void)
 					       "max cores %u, capping them\n",
 					       cpuidx, nr_cpu_ids)) {
 			cpuidx = nr_cpu_ids;
+			of_node_put(cpu);
 			break;
 		}
 
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 3e1c26eb32b4..3ce377f7251f 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -427,8 +427,7 @@ ENDPROC(__fiq_abt)
 	.endm
 
 	.macro	kuser_cmpxchg_check
-#if !defined(CONFIG_CPU_32v6K) && defined(CONFIG_KUSER_HELPERS) && \
-    !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
+#if !defined(CONFIG_CPU_32v6K) && defined(CONFIG_KUSER_HELPERS)
 #ifndef CONFIG_MMU
 #warning "NPTL on non MMU needs fixing"
 #else
@@ -859,20 +858,7 @@ __kuser_helper_start:
 
 __kuser_cmpxchg64:				@ 0xffff0f60
 
-#if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
-
-	/*
-	 * Poor you.  No fast solution possible...
-	 * The kernel itself must perform the operation.
-	 * A special ghost syscall is used for that (see traps.c).
-	 */
-	stmfd	sp!, {r7, lr}
-	ldr	r7, 1f			@ it's 20 bits
-	swi	__ARM_NR_cmpxchg64
-	ldmfd	sp!, {r7, pc}
-1:	.word	__ARM_NR_cmpxchg64
-
-#elif defined(CONFIG_CPU_32v6K)
+#if defined(CONFIG_CPU_32v6K)
 
 	stmfd	sp!, {r4, r5, r6, r7}
 	ldrd	r4, r5, [r0]			@ load old val
@@ -948,20 +934,7 @@ __kuser_memory_barrier:				@ 0xffff0fa0
 
 __kuser_cmpxchg:				@ 0xffff0fc0
 
-#if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
-
-	/*
-	 * Poor you.  No fast solution possible...
-	 * The kernel itself must perform the operation.
-	 * A special ghost syscall is used for that (see traps.c).
-	 */
-	stmfd	sp!, {r7, lr}
-	ldr	r7, 1f			@ it's 20 bits
-	swi	__ARM_NR_cmpxchg
-	ldmfd	sp!, {r7, pc}
-1:	.word	__ARM_NR_cmpxchg
-
-#elif __LINUX_ARM_ARCH__ < 6
+#if __LINUX_ARM_ARCH__ < 6
 
 #ifdef CONFIG_MMU
 
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index dc7d0a95bd36..6284779d64ee 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -35,7 +35,6 @@
 #include <asm/cputype.h>
 #include <asm/current.h>
 #include <asm/hw_breakpoint.h>
-#include <asm/kdebug.h>
 #include <asm/traps.h>
 
 /* Breakpoint currently in use for each BRP. */
diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c
index fd9eefce0a7b..9232caee7060 100644
--- a/arch/arm/kernel/kgdb.c
+++ b/arch/arm/kernel/kgdb.c
@@ -74,7 +74,7 @@ int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
 void
 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
 {
-	struct pt_regs *thread_regs;
+	struct thread_info *ti;
 	int regno;
 
 	/* Just making sure... */
@@ -86,24 +86,17 @@ sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
 		gdb_regs[regno] = 0;
 
 	/* Otherwise, we have only some registers from switch_to() */
-	thread_regs		= task_pt_regs(task);
-	gdb_regs[_R0]		= thread_regs->ARM_r0;
-	gdb_regs[_R1]		= thread_regs->ARM_r1;
-	gdb_regs[_R2]		= thread_regs->ARM_r2;
-	gdb_regs[_R3]		= thread_regs->ARM_r3;
-	gdb_regs[_R4]		= thread_regs->ARM_r4;
-	gdb_regs[_R5]		= thread_regs->ARM_r5;
-	gdb_regs[_R6]		= thread_regs->ARM_r6;
-	gdb_regs[_R7]		= thread_regs->ARM_r7;
-	gdb_regs[_R8]		= thread_regs->ARM_r8;
-	gdb_regs[_R9]		= thread_regs->ARM_r9;
-	gdb_regs[_R10]		= thread_regs->ARM_r10;
-	gdb_regs[_FP]		= thread_regs->ARM_fp;
-	gdb_regs[_IP]		= thread_regs->ARM_ip;
-	gdb_regs[_SPT]		= thread_regs->ARM_sp;
-	gdb_regs[_LR]		= thread_regs->ARM_lr;
-	gdb_regs[_PC]		= thread_regs->ARM_pc;
-	gdb_regs[_CPSR]		= thread_regs->ARM_cpsr;
+	ti			= task_thread_info(task);
+	gdb_regs[_R4]		= ti->cpu_context.r4;
+	gdb_regs[_R5]		= ti->cpu_context.r5;
+	gdb_regs[_R6]		= ti->cpu_context.r6;
+	gdb_regs[_R7]		= ti->cpu_context.r7;
+	gdb_regs[_R8]		= ti->cpu_context.r8;
+	gdb_regs[_R9]		= ti->cpu_context.r9;
+	gdb_regs[_R10]		= ti->cpu_context.sl;
+	gdb_regs[_FP]		= ti->cpu_context.fp;
+	gdb_regs[_SPT]		= ti->cpu_context.sp;
+	gdb_regs[_PC]		= ti->cpu_context.pc;
 }
 
 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 48185a773852..b26361355dae 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -80,7 +80,7 @@ static DECLARE_COMPLETION(cpu_running);
 
 static struct smp_operations smp_ops;
 
-void __init smp_set_ops(struct smp_operations *ops)
+void __init smp_set_ops(const struct smp_operations *ops)
 {
 	if (ops)
 		smp_ops = *ops;
@@ -400,6 +400,7 @@ asmlinkage void secondary_start_kernel(void)
 
 	local_irq_enable();
 	local_fiq_enable();
+	local_abt_enable();
 
 	/*
 	 * OK, it's off to the idle thread for us
@@ -748,6 +749,15 @@ core_initcall(register_cpufreq_notifier);
 
 static void raise_nmi(cpumask_t *mask)
 {
+	/*
+	 * Generate the backtrace directly if we are running in a calling
+	 * context that is not preemptible by the backtrace IPI. Note
+	 * that nmi_cpu_backtrace() automatically removes the current cpu
+	 * from mask.
+	 */
+	if (cpumask_test_cpu(smp_processor_id(), mask) && irqs_disabled())
+		nmi_cpu_backtrace(NULL);
+
 	smp_cross_call(mask, IPI_CPU_BACKTRACE);
 }
 
diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index e9035cda1485..1bfa7a7f5533 100644
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -23,7 +23,6 @@
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
 
-#include <asm/smp_plat.h>
 #include <asm/smp_twd.h>
 
 /* set up by the platform code */
@@ -34,6 +33,8 @@ static unsigned long twd_timer_rate;
 static DEFINE_PER_CPU(bool, percpu_setup_called);
 
 static struct clock_event_device __percpu *twd_evt;
+static unsigned int twd_features =
+		CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
 static int twd_ppi;
 
 static int twd_shutdown(struct clock_event_device *clk)
@@ -294,8 +295,7 @@ static void twd_timer_setup(void)
 	writel_relaxed(0, twd_base + TWD_TIMER_CONTROL);
 
 	clk->name = "local_timer";
-	clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
-			CLOCK_EVT_FEAT_C3STOP;
+	clk->features = twd_features;
 	clk->rating = 350;
 	clk->set_state_shutdown = twd_shutdown;
 	clk->set_state_periodic = twd_set_periodic;
@@ -350,6 +350,8 @@ static int __init twd_local_timer_common_register(struct device_node *np)
 		goto out_irq;
 
 	twd_get_clock(np);
+	if (!of_property_read_bool(np, "always-on"))
+		twd_features |= CLOCK_EVT_FEAT_C3STOP;
 
 	/*
 	 * Immediately configure the timer on the boot CPU, unless we need
@@ -392,9 +394,6 @@ static void __init twd_local_timer_of_register(struct device_node *np)
 {
 	int err;
 
-	if (!is_smp() || !setup_max_cpus)
-		return;
-
 	twd_ppi = irq_of_parse_and_map(np, 0);
 	if (!twd_ppi) {
 		err = -EINVAL;
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 969f9d9e665f..bc698383e822 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -625,58 +625,6 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
 		set_tls(regs->ARM_r0);
 		return 0;
 
-#ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG
-	/*
-	 * Atomically store r1 in *r2 if *r2 is equal to r0 for user space.
-	 * Return zero in r0 if *MEM was changed or non-zero if no exchange
-	 * happened.  Also set the user C flag accordingly.
-	 * If access permissions have to be fixed up then non-zero is
-	 * returned and the operation has to be re-attempted.
-	 *
-	 * *NOTE*: This is a ghost syscall private to the kernel.  Only the
-	 * __kuser_cmpxchg code in entry-armv.S should be aware of its
-	 * existence.  Don't ever use this from user code.
-	 */
-	case NR(cmpxchg):
-	for (;;) {
-		extern void do_DataAbort(unsigned long addr, unsigned int fsr,
-					 struct pt_regs *regs);
-		unsigned long val;
-		unsigned long addr = regs->ARM_r2;
-		struct mm_struct *mm = current->mm;
-		pgd_t *pgd; pmd_t *pmd; pte_t *pte;
-		spinlock_t *ptl;
-
-		regs->ARM_cpsr &= ~PSR_C_BIT;
-		down_read(&mm->mmap_sem);
-		pgd = pgd_offset(mm, addr);
-		if (!pgd_present(*pgd))
-			goto bad_access;
-		pmd = pmd_offset(pgd, addr);
-		if (!pmd_present(*pmd))
-			goto bad_access;
-		pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
-		if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) {
-			pte_unmap_unlock(pte, ptl);
-			goto bad_access;
-		}
-		val = *(unsigned long *)addr;
-		val -= regs->ARM_r0;
-		if (val == 0) {
-			*(unsigned long *)addr = regs->ARM_r1;
-			regs->ARM_cpsr |= PSR_C_BIT;
-		}
-		pte_unmap_unlock(pte, ptl);
-		up_read(&mm->mmap_sem);
-		return val;
-
-		bad_access:
-		up_read(&mm->mmap_sem);
-		/* simulate a write access fault */
-		do_DataAbort(addr, 15 + (1 << 11), regs);
-	}
-#endif
-
 	default:
 		/* Calls 9f00xx..9f07ff are defined to return -ENOSYS
 		   if not implemented, rather than raising SIGILL.  This