Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm

Pull ARM fixes from Russell King:
 "Another round of ARM fixes, which include:
   - Fixing a problem with LPAE mapping sections
   - Reporting of some hwcaps on Krait CPUs
   - Avoiding repetitive warnings in the breakpoint code
   - Fixing a build error noticed on Dove platforms with PJ4 CPUs
   - Fix masking of level 2 cache revision.
   - Fixing timer-based udelay()
   - A larger fix for an erratum causing people major grief with Cortex
     A15 CPUs"

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7690/1: mm: fix CONFIG_LPAE typos
  ARM: 7689/1: add unwind annotations to ftrace asm
  ARM: 7685/1: delay: use private ticks_per_jiffy field for timer-based delay ops
  ARM: 7684/1: errata: Workaround for Cortex-A15 erratum 798181 (TLBI/DSB operations)
  ARM: 7682/1: cache-l2x0: fix masking of RTL revision numbering and set_debug init
  ARM: iWMMXt: always enable iWMMXt support with PJ4 CPUs
  ARM: 7681/1: hw_breakpoint: use warn_once to avoid spam from reset_ctrl_regs()
  ARM: 7678/1: Work around faulty ISAR0 register in some Krait CPUs
  ARM: 7680/1: Detect support for SDIV/UDIV from ISAR0 register
  ARM: 7679/1: Clear IDIVT hwcap if CONFIG_ARM_THUMB=n
  ARM: 7677/1: LPAE: Fix mapping in alloc_init_section for unaligned addresses
  ARM: KVM: vgic: take distributor lock on sync_hwstate path
  ARM: KVM: vgic: force EOIed LRs to the empty state

arch/arm/Kconfig

@@ -1183,9 +1183,9 @@ config ARM_NR_BANKS
 	default 8
 
 config IWMMXT
-	bool "Enable iWMMXt support"
+	bool "Enable iWMMXt support" if !CPU_PJ4
 	depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4
-	default y if PXA27x || PXA3xx || ARCH_MMP
+	default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4
 	help
 	  Enable support for iWMMXt context switching at run time if
 	  running on a CPU that supports it.
@@ -1439,6 +1439,16 @@ config ARM_ERRATA_775420
 	 to deadlock. This workaround puts DSB before executing ISB if
 	 an abort may occur on cache maintenance.
 
+config ARM_ERRATA_798181
+	bool "ARM errata: TLBI/DSB failure on Cortex-A15"
+	depends on CPU_V7 && SMP
+	help
+	  On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
+	  adequately shooting down all use of the old entries. This
+	  option enables the Linux kernel workaround for this erratum
+	  which sends an IPI to the CPUs that are running the same ASID
+	  as the one being invalidated.
+
 endmenu
 
 source "arch/arm/common/Kconfig"

arch/arm/include/asm/delay.h

@@ -24,7 +24,7 @@ extern struct arm_delay_ops {
 	void (*delay)(unsigned long);
 	void (*const_udelay)(unsigned long);
 	void (*udelay)(unsigned long);
-	bool const_clock;
+	unsigned long ticks_per_jiffy;
 } arm_delay_ops;
 
 #define __delay(n)		arm_delay_ops.delay(n)

arch/arm/include/asm/highmem.h

@@ -41,6 +41,13 @@ extern void kunmap_high(struct page *page);
 #endif
 #endif
 
+/*
+ * Needed to be able to broadcast the TLB invalidation for kmap.
+ */
+#ifdef CONFIG_ARM_ERRATA_798181
+#undef ARCH_NEEDS_KMAP_HIGH_GET
+#endif
+
 #ifdef ARCH_NEEDS_KMAP_HIGH_GET
 extern void *kmap_high_get(struct page *page);
 #else

arch/arm/include/asm/mmu_context.h

@@ -27,6 +27,8 @@ void __check_vmalloc_seq(struct mm_struct *mm);
 void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk);
 #define init_new_context(tsk,mm)	({ atomic64_set(&mm->context.id, 0); 0; })
 
+DECLARE_PER_CPU(atomic64_t, active_asids);
+
 #else	/* !CONFIG_CPU_HAS_ASID */
 
 #ifdef CONFIG_MMU

arch/arm/include/asm/tlbflush.h

@@ -450,6 +450,21 @@ static inline void local_flush_bp_all(void)
 		isb();
 }
 
+#ifdef CONFIG_ARM_ERRATA_798181
+static inline void dummy_flush_tlb_a15_erratum(void)
+{
+	/*
+	 * Dummy TLBIMVAIS. Using the unmapped address 0 and ASID 0.
+	 */
+	asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (0));
+	dsb();
+}
+#else
+static inline void dummy_flush_tlb_a15_erratum(void)
+{
+}
+#endif
+
 /*
  *	flush_pmd_entry
  *

arch/arm/kernel/entry-common.S

@@ -276,7 +276,13 @@ ENDPROC(ftrace_graph_caller_old)
  */
 
 .macro mcount_enter
+/*
+ * This pad compensates for the push {lr} at the call site.  Note that we are
+ * unable to unwind through a function which does not otherwise save its lr.
+ */
+ UNWIND(.pad	#4)
 	stmdb	sp!, {r0-r3, lr}
+ UNWIND(.save	{r0-r3, lr})
 .endm
 
 .macro mcount_get_lr reg
@@ -289,24 +295,30 @@ ENDPROC(ftrace_graph_caller_old)
 .endm
 
 ENTRY(__gnu_mcount_nc)
+UNWIND(.fnstart)
 #ifdef CONFIG_DYNAMIC_FTRACE
 	mov	ip, lr
 	ldmia	sp!, {lr}
 	mov	pc, ip
 #else
 	__mcount
 #endif
+UNWIND(.fnend)
 ENDPROC(__gnu_mcount_nc)
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 ENTRY(ftrace_caller)
+UNWIND(.fnstart)
 	__ftrace_caller
+UNWIND(.fnend)
 ENDPROC(ftrace_caller)
 #endif
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 ENTRY(ftrace_graph_caller)
+UNWIND(.fnstart)
 	__ftrace_graph_caller
+UNWIND(.fnend)
 ENDPROC(ftrace_graph_caller)
 #endif
 

arch/arm/kernel/head.S

@@ -267,7 +267,7 @@ __create_page_tables:
 	addne	r6, r6, #1 << SECTION_SHIFT
 	strne	r6, [r3]
 
-#if defined(CONFIG_LPAE) && defined(CONFIG_CPU_ENDIAN_BE8)
+#if defined(CONFIG_ARM_LPAE) && defined(CONFIG_CPU_ENDIAN_BE8)
 	sub	r4, r4, #4			@ Fixup page table pointer
 						@ for 64-bit descriptors
 #endif

arch/arm/kernel/hw_breakpoint.c

@@ -966,7 +966,7 @@ static void reset_ctrl_regs(void *unused)
 	}
 
 	if (err) {
-		pr_warning("CPU %d debug is powered down!\n", cpu);
+		pr_warn_once("CPU %d debug is powered down!\n", cpu);
 		cpumask_or(&debug_err_mask, &debug_err_mask, cpumask_of(cpu));
 		return;
 	}
@@ -987,7 +987,7 @@ static void reset_ctrl_regs(void *unused)
 	isb();
 
 	if (cpumask_intersects(&debug_err_mask, cpumask_of(cpu))) {
-		pr_warning("CPU %d failed to disable vector catch\n", cpu);
+		pr_warn_once("CPU %d failed to disable vector catch\n", cpu);
 		return;
 	}
 
@@ -1007,7 +1007,7 @@ static void reset_ctrl_regs(void *unused)
 	}
 
 	if (cpumask_intersects(&debug_err_mask, cpumask_of(cpu))) {
-		pr_warning("CPU %d failed to clear debug register pairs\n", cpu);
+		pr_warn_once("CPU %d failed to clear debug register pairs\n", cpu);
 		return;
 	}
 

arch/arm/kernel/setup.c

@@ -353,6 +353,23 @@ void __init early_print(const char *str, ...)
 	printk("%s", buf);
 }
 
+static void __init cpuid_init_hwcaps(void)
+{
+	unsigned int divide_instrs;
+
+	if (cpu_architecture() < CPU_ARCH_ARMv7)
+		return;
+
+	divide_instrs = (read_cpuid_ext(CPUID_EXT_ISAR0) & 0x0f000000) >> 24;
+
+	switch (divide_instrs) {
+	case 2:
+		elf_hwcap |= HWCAP_IDIVA;
+	case 1:
+		elf_hwcap |= HWCAP_IDIVT;
+	}
+}
+
 static void __init feat_v6_fixup(void)
 {
 	int id = read_cpuid_id();
@@ -483,8 +500,11 @@ static void __init setup_processor(void)
 	snprintf(elf_platform, ELF_PLATFORM_SIZE, "%s%c",
 		 list->elf_name, ENDIANNESS);
 	elf_hwcap = list->elf_hwcap;
+
+	cpuid_init_hwcaps();
+
 #ifndef CONFIG_ARM_THUMB
-	elf_hwcap &= ~HWCAP_THUMB;
+	elf_hwcap &= ~(HWCAP_THUMB | HWCAP_IDIVT);
 #endif
 
 	feat_v6_fixup();
@@ -524,7 +544,7 @@ int __init arm_add_memory(phys_addr_t start, phys_addr_t size)
 	size -= start & ~PAGE_MASK;
 	bank->start = PAGE_ALIGN(start);
 
-#ifndef CONFIG_LPAE
+#ifndef CONFIG_ARM_LPAE
 	if (bank->start + size < bank->start) {
 		printk(KERN_CRIT "Truncating memory at 0x%08llx to fit in "
 			"32-bit physical address space\n", (long long)start);

arch/arm/kernel/smp.c

@@ -673,9 +673,6 @@ static int cpufreq_callback(struct notifier_block *nb,
 	if (freq->flags & CPUFREQ_CONST_LOOPS)
 		return NOTIFY_OK;
 
-	if (arm_delay_ops.const_clock)
-		return NOTIFY_OK;
-
 	if (!per_cpu(l_p_j_ref, cpu)) {
 		per_cpu(l_p_j_ref, cpu) =
 			per_cpu(cpu_data, cpu).loops_per_jiffy;

arch/arm/kernel/smp_tlb.c

@@ -12,6 +12,7 @@
 
 #include <asm/smp_plat.h>
 #include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
 
 /**********************************************************************/
 
@@ -69,12 +70,72 @@ static inline void ipi_flush_bp_all(void *ignored)
 	local_flush_bp_all();
 }
 
+#ifdef CONFIG_ARM_ERRATA_798181
+static int erratum_a15_798181(void)
+{
+	unsigned int midr = read_cpuid_id();
+
+	/* Cortex-A15 r0p0..r3p2 affected */
+	if ((midr & 0xff0ffff0) != 0x410fc0f0 || midr > 0x413fc0f2)
+		return 0;
+	return 1;
+}
+#else
+static int erratum_a15_798181(void)
+{
+	return 0;
+}
+#endif
+
+static void ipi_flush_tlb_a15_erratum(void *arg)
+{
+	dmb();
+}
+
+static void broadcast_tlb_a15_erratum(void)
+{
+	if (!erratum_a15_798181())
+		return;
+
+	dummy_flush_tlb_a15_erratum();
+	smp_call_function_many(cpu_online_mask, ipi_flush_tlb_a15_erratum,
+			       NULL, 1);
+}
+
+static void broadcast_tlb_mm_a15_erratum(struct mm_struct *mm)
+{
+	int cpu;
+	cpumask_t mask = { CPU_BITS_NONE };
+
+	if (!erratum_a15_798181())
+		return;
+
+	dummy_flush_tlb_a15_erratum();
+	for_each_online_cpu(cpu) {
+		if (cpu == smp_processor_id())
+			continue;
+		/*
+		 * We only need to send an IPI if the other CPUs are running
+		 * the same ASID as the one being invalidated. There is no
+		 * need for locking around the active_asids check since the
+		 * switch_mm() function has at least one dmb() (as required by
+		 * this workaround) in case a context switch happens on
+		 * another CPU after the condition below.
+		 */
+		if (atomic64_read(&mm->context.id) ==
+		    atomic64_read(&per_cpu(active_asids, cpu)))
+			cpumask_set_cpu(cpu, &mask);
+	}
+	smp_call_function_many(&mask, ipi_flush_tlb_a15_erratum, NULL, 1);
+}
+
 void flush_tlb_all(void)
 {
 	if (tlb_ops_need_broadcast())
 		on_each_cpu(ipi_flush_tlb_all, NULL, 1);
 	else
 		local_flush_tlb_all();
+	broadcast_tlb_a15_erratum();
 }
 
 void flush_tlb_mm(struct mm_struct *mm)
@@ -83,6 +144,7 @@ void flush_tlb_mm(struct mm_struct *mm)
 		on_each_cpu_mask(mm_cpumask(mm), ipi_flush_tlb_mm, mm, 1);
 	else
 		local_flush_tlb_mm(mm);
+	broadcast_tlb_mm_a15_erratum(mm);
 }
 
 void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
@@ -95,6 +157,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
 					&ta, 1);
 	} else
 		local_flush_tlb_page(vma, uaddr);
+	broadcast_tlb_mm_a15_erratum(vma->vm_mm);
 }
 
 void flush_tlb_kernel_page(unsigned long kaddr)
@@ -105,6 +168,7 @@ void flush_tlb_kernel_page(unsigned long kaddr)
 		on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1);
 	} else
 		local_flush_tlb_kernel_page(kaddr);
+	broadcast_tlb_a15_erratum();
 }
 
 void flush_tlb_range(struct vm_area_struct *vma,
@@ -119,6 +183,7 @@ void flush_tlb_range(struct vm_area_struct *vma,
 					&ta, 1);
 	} else
 		local_flush_tlb_range(vma, start, end);
+	broadcast_tlb_mm_a15_erratum(vma->vm_mm);
 }
 
 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
@@ -130,6 +195,7 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 		on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);
 	} else
 		local_flush_tlb_kernel_range(start, end);
+	broadcast_tlb_a15_erratum();
 }
 
 void flush_bp_all(void)