10 files changed, 130 insertions, 49 deletions

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index c0225da3fb21..f06ff9feb0db 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -391,6 +391,7 @@ ENDPROC(__turn_mmu_on)
 
 
 #ifdef CONFIG_SMP_ON_UP
+        __INIT
 __fixup_smp:
         and     r3, r9, #0x000f0000     @ architecture version
         teq     r3, #0x000f0000         @ CPU ID supported?
@@ -415,18 +416,7 @@ __fixup_smp_on_up:
         sub     r3, r0, r3
         add     r4, r4, r3
         add     r5, r5, r3
-2:      cmp     r4, r5
-        movhs   pc, lr
-        ldmia   r4!, {r0, r6}
- ARM(   str     r6, [r0, r3]    )
- THUMB( add     r0, r0, r3      )
-#ifdef __ARMEB__
- THUMB( mov     r6, r6, ror #16 )       @ Convert word order for big-endian.
-#endif
- THUMB( strh    r6, [r0], #2    )       @ For Thumb-2, store as two halfwords
- THUMB( mov     r6, r6, lsr #16 )       @ to be robust against misaligned r3.
- THUMB( strh    r6, [r0]        )
-        b       2b
+        b       __do_fixup_smp_on_up
 ENDPROC(__fixup_smp)
 
         .align
@@ -440,7 +430,31 @@ smp_on_up:
         ALT_SMP(.long   1)
         ALT_UP(.long    0)
         .popsection
+#endif
 
+        .text
+__do_fixup_smp_on_up:
+        cmp     r4, r5
+        movhs   pc, lr
+        ldmia   r4!, {r0, r6}
+ ARM(   str     r6, [r0, r3]    )
+ THUMB( add     r0, r0, r3      )
+#ifdef __ARMEB__
+ THUMB( mov     r6, r6, ror #16 )       @ Convert word order for big-endian.
 #endif
+ THUMB( strh    r6, [r0], #2    )       @ For Thumb-2, store as two halfwords
+ THUMB( mov     r6, r6, lsr #16 )       @ to be robust against misaligned r3.
+ THUMB( strh    r6, [r0]        )
+        b       __do_fixup_smp_on_up
+ENDPROC(__do_fixup_smp_on_up)
+
+ENTRY(fixup_smp)
+        stmfd   sp!, {r4 - r6, lr}
+        mov     r4, r0
+        add     r5, r0, r1
+        mov     r3, #0
+        bl      __do_fixup_smp_on_up
+        ldmfd   sp!, {r4 - r6, pc}
+ENDPROC(fixup_smp)
 
 #include "head-common.S"
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index c9f3f0467570..44b84fe6e1b0 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -137,11 +137,10 @@ static u8 get_debug_arch(void)
         u32 didr;
 
         /* Do we implement the extended CPUID interface? */
-        if (((read_cpuid_id() >> 16) & 0xf) != 0xf) {
-                pr_warning("CPUID feature registers not supported. "
-                                "Assuming v6 debug is present.\n");
+        if (WARN_ONCE((((read_cpuid_id() >> 16) & 0xf) != 0xf),
+            "CPUID feature registers not supported. "
+            "Assuming v6 debug is present.\n"))
                 return ARM_DEBUG_ARCH_V6;
-        }
 
         ARM_DBG_READ(c0, 0, didr);
         return (didr >> 16) & 0xf;
@@ -152,6 +151,12 @@ u8 arch_get_debug_arch(void)
         return debug_arch;
 }
 
+static int debug_arch_supported(void)
+{
+        u8 arch = get_debug_arch();
+        return arch >= ARM_DEBUG_ARCH_V6 && arch <= ARM_DEBUG_ARCH_V7_ECP14;
+}
+
 /* Determine number of BRP register available. */
 static int get_num_brp_resources(void)
 {
@@ -268,6 +273,9 @@ out:
 
 int hw_breakpoint_slots(int type)
 {
+        if (!debug_arch_supported())
+                return 0;
+
         /*
          * We can be called early, so don't rely on
          * our static variables being initialised.
@@ -828,20 +836,33 @@ static int hw_breakpoint_pending(unsigned long addr, unsigned int fsr,
 /*
  * One-time initialisation.
  */
-static void reset_ctrl_regs(void *unused)
+static void reset_ctrl_regs(void *info)
 {
-        int i;
+        int i, cpu = smp_processor_id();
+        u32 dbg_power;
+        cpumask_t *cpumask = info;
 
         /*
          * v7 debug contains save and restore registers so that debug state
-         * can be maintained across low-power modes without leaving
-         * the debug logic powered up. It is IMPLEMENTATION DEFINED whether
-         * we can write to the debug registers out of reset, so we must
-         * unlock the OS Lock Access Register to avoid taking undefined
-         * instruction exceptions later on.
+         * can be maintained across low-power modes without leaving the debug
+         * logic powered up. It is IMPLEMENTATION DEFINED whether we can access
+         * the debug registers out of reset, so we must unlock the OS Lock
+         * Access Register to avoid taking undefined instruction exceptions
+         * later on.
          */
         if (debug_arch >= ARM_DEBUG_ARCH_V7_ECP14) {
                 /*
+                 * Ensure sticky power-down is clear (i.e. debug logic is
+                 * powered up).
+                 */
+                asm volatile("mrc p14, 0, %0, c1, c5, 4" : "=r" (dbg_power));
+                if ((dbg_power & 0x1) == 0) {
+                        pr_warning("CPU %d debug is powered down!\n", cpu);
+                        cpumask_or(cpumask, cpumask, cpumask_of(cpu));
+                        return;
+                }
+
+                /*
                  * Unconditionally clear the lock by writing a value
                  * other than 0xC5ACCE55 to the access register.
                  */
@@ -879,10 +900,11 @@ static struct notifier_block __cpuinitdata dbg_reset_nb = {
 static int __init arch_hw_breakpoint_init(void)
 {
         u32 dscr;
+        cpumask_t cpumask = { CPU_BITS_NONE };
 
         debug_arch = get_debug_arch();
 
-        if (debug_arch > ARM_DEBUG_ARCH_V7_ECP14) {
+        if (!debug_arch_supported()) {
                 pr_info("debug architecture 0x%x unsupported.\n", debug_arch);
                 return 0;
         }
@@ -899,18 +921,24 @@ static int __init arch_hw_breakpoint_init(void)
                 pr_info("%d breakpoint(s) reserved for watchpoint "
                                 "single-step.\n", core_num_reserved_brps);
 
+        /*
+         * Reset the breakpoint resources. We assume that a halting
+         * debugger will leave the world in a nice state for us.
+         */
+        on_each_cpu(reset_ctrl_regs, &cpumask, 1);
+        if (!cpumask_empty(&cpumask)) {
+                core_num_brps = 0;
+                core_num_reserved_brps = 0;
+                core_num_wrps = 0;
+                return 0;
+        }
+
         ARM_DBG_READ(c1, 0, dscr);
         if (dscr & ARM_DSCR_HDBGEN) {
+                max_watchpoint_len = 4;
                 pr_warning("halting debug mode enabled. Assuming maximum "
-                                "watchpoint size of 4 bytes.");
+                           "watchpoint size of %u bytes.", max_watchpoint_len);
         } else {
-                /*
-                 * Reset the breakpoint resources. We assume that a halting
-                 * debugger will leave the world in a nice state for us.
-                 */
-                smp_call_function(reset_ctrl_regs, NULL, 1);
-                reset_ctrl_regs(NULL);
-
                 /* Work out the maximum supported watchpoint length. */
                 max_watchpoint_len = get_max_wp_len();
                 pr_info("maximum watchpoint size is %u bytes.\n",
diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c
index 2c1f0050c9c4..8f6ed43861f1 100644
--- a/arch/arm/kernel/kprobes-decode.c
+++ b/arch/arm/kernel/kprobes-decode.c
@@ -1437,7 +1437,7 @@ arm_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
 
                 return space_cccc_1100_010x(insn, asi);
 
-        } else if ((insn & 0x0e000000) == 0x0c400000) {
+        } else if ((insn & 0x0e000000) == 0x0c000000) {
 
                 return space_cccc_110x(insn, asi);
 
diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
index 2cfe8161b478..6d4105e6872f 100644
--- a/arch/arm/kernel/module.c
+++ b/arch/arm/kernel/module.c
@@ -22,6 +22,7 @@
 
 #include <asm/pgtable.h>
 #include <asm/sections.h>
+#include <asm/smp_plat.h>
 #include <asm/unwind.h>
 
 #ifdef CONFIG_XIP_KERNEL
@@ -268,12 +269,28 @@ struct mod_unwind_map {
         const Elf_Shdr *txt_sec;
 };
 
+static const Elf_Shdr *find_mod_section(const Elf32_Ehdr *hdr,
+        const Elf_Shdr *sechdrs, const char *name)
+{
+        const Elf_Shdr *s, *se;
+        const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+
+        for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++)
+                if (strcmp(name, secstrs + s->sh_name) == 0)
+                        return s;
+
+        return NULL;
+}
+
+extern void fixup_smp(const void *, unsigned long);
+
 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
                     struct module *mod)
 {
+        const Elf_Shdr * __maybe_unused s = NULL;
 #ifdef CONFIG_ARM_UNWIND
         const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
-        const Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;
+        const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum;
         struct mod_unwind_map maps[ARM_SEC_MAX];
         int i;
 
@@ -315,6 +332,9 @@ int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
                                                  maps[i].txt_sec->sh_addr,
                                                  maps[i].txt_sec->sh_size);
 #endif
+        s = find_mod_section(hdr, sechdrs, ".alt.smp.init");
+        if (s && !is_smp())
+                fixup_smp((void *)s->sh_addr, s->sh_size);
         return 0;
 }
 
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 5efa2647a2fb..d150ad1ccb5d 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -700,7 +700,7 @@ user_backtrace(struct frame_tail __user *tail,
          * Frame pointers should strictly progress back up the stack
          * (towards higher addresses).
          */
-        if (tail >= buftail.fp)
+        if (tail + 1 >= buftail.fp)
                 return NULL;
 
         return buftail.fp - 1;
diff --git a/arch/arm/kernel/pmu.c b/arch/arm/kernel/pmu.c
index b8af96ea62e6..2c79eec19262 100644
--- a/arch/arm/kernel/pmu.c
+++ b/arch/arm/kernel/pmu.c
@@ -97,28 +97,34 @@ set_irq_affinity(int irq,
                            irq, cpu);
         return err;
 #else
-        return 0;
+        return -EINVAL;
 #endif
 }
 
 static int
 init_cpu_pmu(void)
 {
-        int i, err = 0;
+        int i, irqs, err = 0;
         struct platform_device *pdev = pmu_devices[ARM_PMU_DEVICE_CPU];
 
-        if (!pdev) {
-                err = -ENODEV;
-                goto out;
-        }
+        if (!pdev)
+                return -ENODEV;
+
+        irqs = pdev->num_resources;
+
+        /*
+         * If we have a single PMU interrupt that we can't shift, assume that
+         * we're running on a uniprocessor machine and continue.
+         */
+        if (irqs == 1 && !irq_can_set_affinity(platform_get_irq(pdev, 0)))
+                return 0;
 
-        for (i = 0; i < pdev->num_resources; ++i) {
+        for (i = 0; i < irqs; ++i) {
                 err = set_irq_affinity(platform_get_irq(pdev, i), i);
                 if (err)
                         break;
         }
 
-out:
         return err;
 }
 
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 19c6816db61e..b13e70f63d71 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -996,10 +996,10 @@ static int ptrace_gethbpregs(struct task_struct *tsk, long num,
                 while (!(arch_ctrl.len & 0x1))
                         arch_ctrl.len >>= 1;
 
-                if (idx & 0x1)
-                        reg = encode_ctrl_reg(arch_ctrl);
-                else
+                if (num & 0x1)
                         reg = bp->attr.bp_addr;
+                else
+                        reg = encode_ctrl_reg(arch_ctrl);
         }
 
 put:
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 420b8d6485d6..5ea4fb718b97 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -226,8 +226,8 @@ int cpu_architecture(void)
                  * Register 0 and check for VMSAv7 or PMSAv7 */
                 asm("mrc        p15, 0, %0, c0, c1, 4"
                     : "=r" (mmfr0));
-                if ((mmfr0 & 0x0000000f) == 0x00000003 ||
-                    (mmfr0 & 0x000000f0) == 0x00000030)
+                if ((mmfr0 & 0x0000000f) >= 0x00000003 ||
+                    (mmfr0 & 0x000000f0) >= 0x00000030)
                         cpu_arch = CPU_ARCH_ARMv7;
                 else if ((mmfr0 & 0x0000000f) == 0x00000002 ||
                          (mmfr0 & 0x000000f0) == 0x00000020)
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 907d5a620bca..abaf8445ce25 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -474,7 +474,9 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka,
         unsigned long handler = (unsigned long)ka->sa.sa_handler;
         unsigned long retcode;
         int thumb = 0;
-        unsigned long cpsr = regs->ARM_cpsr & ~PSR_f;
+        unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT);
+
+        cpsr |= PSR_ENDSTATE;
 
         /*
          * Maybe we need to deliver a 32-bit signal to a 26-bit task.
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 86b66f3f2031..61462790757f 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -21,6 +21,12 @@
 #define ARM_CPU_KEEP(x)
 #endif
 
+#if defined(CONFIG_SMP_ON_UP) && !defined(CONFIG_DEBUG_SPINLOCK)
+#define ARM_EXIT_KEEP(x)        x
+#else
+#define ARM_EXIT_KEEP(x)
+#endif
+
 OUTPUT_ARCH(arm)
 ENTRY(stext)
 
@@ -43,6 +49,7 @@ SECTIONS
                 _sinittext = .;
                         HEAD_TEXT
                         INIT_TEXT
+                        ARM_EXIT_KEEP(EXIT_TEXT)
                 _einittext = .;
                 ARM_CPU_DISCARD(PROC_INFO)
                 __arch_info_begin = .;
@@ -67,6 +74,7 @@ SECTIONS
 #ifndef CONFIG_XIP_KERNEL
                 __init_begin = _stext;
                 INIT_DATA
+                ARM_EXIT_KEEP(EXIT_DATA)
 #endif
         }
 
@@ -162,6 +170,7 @@ SECTIONS
                 . = ALIGN(PAGE_SIZE);
                 __init_begin = .;
                 INIT_DATA
+                ARM_EXIT_KEEP(EXIT_DATA)
                 . = ALIGN(PAGE_SIZE);
                 __init_end = .;
 #endif
@@ -247,6 +256,8 @@ SECTIONS
         }
 #endif
 
+        NOTES
+
         BSS_SECTION(0, 0, 0)
         _end = .;