11 files changed, 55 insertions, 108 deletions

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 45d79ea890ae..5fed98ca0e1f 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -65,7 +65,8 @@ __setup("noreplace-paravirt", setup_noreplace_paravirt);
    get them easily into strings. */
 asm("\t.section .rodata, \"a\"\nintelnops: "
         GENERIC_NOP1 GENERIC_NOP2 GENERIC_NOP3 GENERIC_NOP4 GENERIC_NOP5 GENERIC_NOP6
-        GENERIC_NOP7 GENERIC_NOP8);
+        GENERIC_NOP7 GENERIC_NOP8
+    "\t.previous");
 extern const unsigned char intelnops[];
 static const unsigned char *const intel_nops[ASM_NOP_MAX+1] = {
         NULL,
@@ -83,7 +84,8 @@ static const unsigned char *const intel_nops[ASM_NOP_MAX+1] = {
 #ifdef K8_NOP1
 asm("\t.section .rodata, \"a\"\nk8nops: "
         K8_NOP1 K8_NOP2 K8_NOP3 K8_NOP4 K8_NOP5 K8_NOP6
-        K8_NOP7 K8_NOP8);
+        K8_NOP7 K8_NOP8
+    "\t.previous");
 extern const unsigned char k8nops[];
 static const unsigned char *const k8_nops[ASM_NOP_MAX+1] = {
         NULL,
@@ -101,7 +103,8 @@ static const unsigned char *const k8_nops[ASM_NOP_MAX+1] = {
 #ifdef K7_NOP1
 asm("\t.section .rodata, \"a\"\nk7nops: "
         K7_NOP1 K7_NOP2 K7_NOP3 K7_NOP4 K7_NOP5 K7_NOP6
-        K7_NOP7 K7_NOP8);
+        K7_NOP7 K7_NOP8
+    "\t.previous");
 extern const unsigned char k7nops[];
 static const unsigned char *const k7_nops[ASM_NOP_MAX+1] = {
         NULL,
@@ -119,7 +122,8 @@ static const unsigned char *const k7_nops[ASM_NOP_MAX+1] = {
 #ifdef P6_NOP1
 asm("\t.section .rodata, \"a\"\np6nops: "
         P6_NOP1 P6_NOP2 P6_NOP3 P6_NOP4 P6_NOP5 P6_NOP6
-        P6_NOP7 P6_NOP8);
+        P6_NOP7 P6_NOP8
+    "\t.previous");
 extern const unsigned char p6nops[];
 static const unsigned char *const p6_nops[ASM_NOP_MAX+1] = {
         NULL,
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 027e5c003b16..170d2f5523b2 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -143,14 +143,6 @@ static void __init check_config(void)
 #endif
 
 /*
- * If we configured ourselves for a TSC, we'd better have one!
- */
-#ifdef CONFIG_X86_TSC
-        if (!cpu_has_tsc)
-                panic("Kernel compiled for Pentium+, requires TSC feature!");
-#endif
-
-/*
  * If we were told we had a good local APIC, check for buggy Pentia,
  * i.e. all B steppings and the C2 stepping of P54C when using their
  * integrated APIC (see 11AP erratum in "Pentium Processor
diff --git a/arch/x86/kernel/cpu/perfctr-watchdog.c b/arch/x86/kernel/cpu/perfctr-watchdog.c
index 9b838324b818..b943e10ad814 100644
--- a/arch/x86/kernel/cpu/perfctr-watchdog.c
+++ b/arch/x86/kernel/cpu/perfctr-watchdog.c
@@ -652,9 +652,6 @@ static void probe_nmi_watchdog(void)
                         wd_ops = &p6_wd_ops;
                         break;
                 case 15:
-                        if (boot_cpu_data.x86_model > 0x4)
-                                return;
-
                         wd_ops = &p4_wd_ops;
                         break;
                 default:
@@ -670,8 +667,10 @@ int lapic_watchdog_init(unsigned nmi_hz)
 {
         if (!wd_ops) {
                 probe_nmi_watchdog();
-                if (!wd_ops)
+                if (!wd_ops) {
+                        printk(KERN_INFO "NMI watchdog: CPU not supported\n");
                         return -1;
+                }
 
                 if (!wd_ops->reserve()) {
                         printk(KERN_ERR
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 235fd6c77504..36652ea1a265 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -133,13 +133,16 @@ static void hpet_reserve_platform_timers(unsigned long id)
 #ifdef CONFIG_HPET_EMULATE_RTC
         hpet_reserve_timer(&hd, 1);
 #endif
+
         hd.hd_irq[0] = HPET_LEGACY_8254;
         hd.hd_irq[1] = HPET_LEGACY_RTC;
 
-       for (i = 2; i < nrtimers; timer++, i++)
-               hd.hd_irq[i] = (timer->hpet_config & Tn_INT_ROUTE_CNF_MASK) >>
-                       Tn_INT_ROUTE_CNF_SHIFT;
+        for (i = 2; i < nrtimers; timer++, i++)
+                hd.hd_irq[i] = (timer->hpet_config & Tn_INT_ROUTE_CNF_MASK) >>
+                        Tn_INT_ROUTE_CNF_SHIFT;
+
         hpet_alloc(&hd);
+
 }
 #else
 static void hpet_reserve_platform_timers(unsigned long id) { }
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index faf3229f8fb3..700e4647dd30 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -615,8 +615,8 @@ static __init int init_k8_gatt(struct agp_kern_info *info)
 
  nommu:
         /* Should not happen anymore */
-        printk(KERN_ERR "PCI-DMA: More than 4GB of RAM and no IOMMU\n"
-               KERN_ERR "PCI-DMA: 32bit PCI IO may malfunction.\n");
+        printk(KERN_WARNING "PCI-DMA: More than 4GB of RAM and no IOMMU\n"
+               KERN_WARNING "falling back to iommu=soft.\n");
         return -1;
 }
 
@@ -692,9 +692,9 @@ void __init gart_iommu_init(void)
             !gart_iommu_aperture ||
             (no_agp && init_k8_gatt(&info) < 0)) {
                 if (end_pfn > MAX_DMA32_PFN) {
-                        printk(KERN_ERR "WARNING more than 4GB of memory "
-                                        "but GART IOMMU not available.\n"
-                               KERN_ERR "WARNING 32bit PCI may malfunction.\n");
+                        printk(KERN_WARNING "More than 4GB of memory "
+                                          "but GART IOMMU not available.\n"
+                               KERN_WARNING "falling back to iommu=soft.\n");
                 }
                 return;
         }
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index be3c7a299f02..43930e73f657 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -82,7 +82,6 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
  */
 void (*pm_idle)(void);
 EXPORT_SYMBOL(pm_idle);
-static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
 
 void disable_hlt(void)
 {
@@ -190,9 +189,6 @@ void cpu_idle(void)
                 while (!need_resched()) {
                         void (*idle)(void);
 
-                        if (__get_cpu_var(cpu_idle_state))
-                                __get_cpu_var(cpu_idle_state) = 0;
-
                         check_pgt_cache();
                         rmb();
                         idle = pm_idle;
@@ -220,40 +216,19 @@ static void do_nothing(void *unused)
 {
 }
 
+/*
+ * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
+ * pm_idle and update to new pm_idle value. Required while changing pm_idle
+ * handler on SMP systems.
+ *
+ * Caller must have changed pm_idle to the new value before the call. Old
+ * pm_idle value will not be used by any CPU after the return of this function.
+ */
 void cpu_idle_wait(void)
 {
-        unsigned int cpu, this_cpu = get_cpu();
-        cpumask_t map, tmp = current->cpus_allowed;
-
-        set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
-        put_cpu();
-
-        cpus_clear(map);
-        for_each_online_cpu(cpu) {
-                per_cpu(cpu_idle_state, cpu) = 1;
-                cpu_set(cpu, map);
-        }
-
-        __get_cpu_var(cpu_idle_state) = 0;
-
-        wmb();
-        do {
-                ssleep(1);
-                for_each_online_cpu(cpu) {
-                        if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
-                                cpu_clear(cpu, map);
-                }
-                cpus_and(map, map, cpu_online_map);
-                /*
-                 * We waited 1 sec, if a CPU still did not call idle
-                 * it may be because it is in idle and not waking up
-                 * because it has nothing to do.
-                 * Give all the remaining CPUS a kick.
-                 */
-                smp_call_function_mask(map, do_nothing, NULL, 0);
-        } while (!cpus_empty(map));
-
-        set_cpus_allowed(current, tmp);
+        smp_mb();
+        /* kick all the CPUs so that they exit out of pm_idle */
+        smp_call_function(do_nothing, NULL, 0, 1);
 }
 EXPORT_SYMBOL_GPL(cpu_idle_wait);
 
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 3baf9b9f4c87..46c4c546b499 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -63,7 +63,6 @@ EXPORT_SYMBOL(boot_option_idle_override);
  */
 void (*pm_idle)(void);
 EXPORT_SYMBOL(pm_idle);
-static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
 
 static ATOMIC_NOTIFIER_HEAD(idle_notifier);
 
@@ -173,9 +172,6 @@ void cpu_idle(void)
                 while (!need_resched()) {
                         void (*idle)(void);
 
-                        if (__get_cpu_var(cpu_idle_state))
-                                __get_cpu_var(cpu_idle_state) = 0;
-
                         rmb();
                         idle = pm_idle;
                         if (!idle)
@@ -207,40 +203,19 @@ static void do_nothing(void *unused)
 {
 }
 
+/*
+ * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
+ * pm_idle and update to new pm_idle value. Required while changing pm_idle
+ * handler on SMP systems.
+ *
+ * Caller must have changed pm_idle to the new value before the call. Old
+ * pm_idle value will not be used by any CPU after the return of this function.
+ */
 void cpu_idle_wait(void)
 {
-        unsigned int cpu, this_cpu = get_cpu();
-        cpumask_t map, tmp = current->cpus_allowed;
-
-        set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
-        put_cpu();
-
-        cpus_clear(map);
-        for_each_online_cpu(cpu) {
-                per_cpu(cpu_idle_state, cpu) = 1;
-                cpu_set(cpu, map);
-        }
-
-        __get_cpu_var(cpu_idle_state) = 0;
-
-        wmb();
-        do {
-                ssleep(1);
-                for_each_online_cpu(cpu) {
-                        if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
-                                cpu_clear(cpu, map);
-                }
-                cpus_and(map, map, cpu_online_map);
-                /*
-                 * We waited 1 sec, if a CPU still did not call idle
-                 * it may be because it is in idle and not waking up
-                 * because it has nothing to do.
-                 * Give all the remaining CPUS a kick.
-                 */
-                smp_call_function_mask(map, do_nothing, 0, 0);
-        } while (!cpus_empty(map));
-
-        set_cpus_allowed(current, tmp);
+        smp_mb();
+        /* kick all the CPUs so that they exit out of pm_idle */
+        smp_call_function(do_nothing, NULL, 0, 1);
 }
 EXPORT_SYMBOL_GPL(cpu_idle_wait);
 
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c
index 9d406cdc847f..071ff4798236 100644
--- a/arch/x86/kernel/step.c
+++ b/arch/x86/kernel/step.c
@@ -140,6 +140,9 @@ static int enable_single_step(struct task_struct *child)
  */
 static void write_debugctlmsr(struct task_struct *child, unsigned long val)
 {
+        if (child->thread.debugctlmsr == val)
+                return;
+
         child->thread.debugctlmsr = val;
 
         if (child != current)
@@ -165,11 +168,11 @@ static void enable_step(struct task_struct *child, bool block)
                 write_debugctlmsr(child,
                                   child->thread.debugctlmsr | DEBUGCTLMSR_BTF);
         } else {
-            write_debugctlmsr(child,
-                              child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF);
+                write_debugctlmsr(child,
+                                  child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF);
 
-            if (!child->thread.debugctlmsr)
-                    clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
+                if (!child->thread.debugctlmsr)
+                        clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
         }
 }
 
diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c
index 022bcaa3b42e..ab6bf375a307 100644
--- a/arch/x86/kernel/tls.c
+++ b/arch/x86/kernel/tls.c
@@ -92,7 +92,7 @@ int do_set_thread_area(struct task_struct *p, int idx,
 asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
 {
         int ret = do_set_thread_area(current, -1, u_info, 1);
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, u_info);
         return ret;
 }
 
@@ -142,7 +142,7 @@ int do_get_thread_area(struct task_struct *p, int idx,
 asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
 {
         int ret = do_get_thread_area(current, -1, u_info);
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, u_info);
         return ret;
 }
 
diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c
index f14cfd9d1f94..c2241e04ea5f 100644
--- a/arch/x86/kernel/tsc_32.c
+++ b/arch/x86/kernel/tsc_32.c
@@ -256,9 +256,7 @@ time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
                                                 ref_freq, freq->new);
                         if (!(freq->flags & CPUFREQ_CONST_LOOPS)) {
                                 tsc_khz = cpu_khz;
-                                preempt_disable();
-                                set_cyc2ns_scale(cpu_khz, smp_processor_id());
-                                preempt_enable();
+                                set_cyc2ns_scale(cpu_khz, freq->cpu);
                                 /*
                                  * TSC based sched_clock turns
                                  * to junk w/ cpufreq
diff --git a/arch/x86/kernel/tsc_64.c b/arch/x86/kernel/tsc_64.c
index 947554ddabb6..d3bebaaad842 100644
--- a/arch/x86/kernel/tsc_64.c
+++ b/arch/x86/kernel/tsc_64.c
@@ -148,9 +148,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
                         mark_tsc_unstable("cpufreq changes");
         }
 
-        preempt_disable();
-        set_cyc2ns_scale(tsc_khz_ref, smp_processor_id());
-        preempt_enable();
+        set_cyc2ns_scale(tsc_khz_ref, freq->cpu);
 
         return 0;
 }