1 files changed, 109 insertions, 16 deletions

diff --git a/arch/x86/kernel/cpu/common_64.c b/arch/x86/kernel/cpu/common_64.c
index dd6e3f15017e..305b465889b0 100644
--- a/arch/x86/kernel/cpu/common_64.c
+++ b/arch/x86/kernel/cpu/common_64.c
@@ -18,6 +18,7 @@
 #include <asm/mtrr.h>
 #include <asm/mce.h>
 #include <asm/pat.h>
+#include <asm/asm.h>
 #include <asm/numa.h>
 #ifdef CONFIG_X86_LOCAL_APIC
 #include <asm/mpspec.h>
@@ -215,6 +216,39 @@ static void __init early_cpu_support_print(void)
         }
 }
 
+/*
+ * The NOPL instruction is supposed to exist on all CPUs with
+ * family >= 6, unfortunately, that's not true in practice because
+ * of early VIA chips and (more importantly) broken virtualizers that
+ * are not easy to detect.  Hence, probe for it based on first
+ * principles.
+ *
+ * Note: no 64-bit chip is known to lack these, but put the code here
+ * for consistency with 32 bits, and to make it utterly trivial to
+ * diagnose the problem should it ever surface.
+ */
+static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
+{
+        const u32 nopl_signature = 0x888c53b1; /* Random number */
+        u32 has_nopl = nopl_signature;
+
+        clear_cpu_cap(c, X86_FEATURE_NOPL);
+        if (c->x86 >= 6) {
+                asm volatile("\n"
+                             "1:      .byte 0x0f,0x1f,0xc0\n" /* nopl %eax */
+                             "2:\n"
+                             "        .section .fixup,\"ax\"\n"
+                             "3:      xor %0,%0\n"
+                             "        jmp 2b\n"
+                             "        .previous\n"
+                             _ASM_EXTABLE(1b,3b)
+                             : "+a" (has_nopl));
+
+                if (has_nopl == nopl_signature)
+                        set_cpu_cap(c, X86_FEATURE_NOPL);
+        }
+}
+
 static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c);
 
 void __init early_cpu_init(void)
@@ -313,6 +347,8 @@ static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
                 c->x86_phys_bits = eax & 0xff;
         }
 
+        detect_nopl(c);
+
         if (c->x86_vendor != X86_VENDOR_UNKNOWN &&
             cpu_devs[c->x86_vendor]->c_early_init)
                 cpu_devs[c->x86_vendor]->c_early_init(c);
@@ -394,6 +430,49 @@ static __init int setup_noclflush(char *arg)
 }
 __setup("noclflush", setup_noclflush);
 
+struct msr_range {
+        unsigned min;
+        unsigned max;
+};
+
+static struct msr_range msr_range_array[] __cpuinitdata = {
+        { 0x00000000, 0x00000418},
+        { 0xc0000000, 0xc000040b},
+        { 0xc0010000, 0xc0010142},
+        { 0xc0011000, 0xc001103b},
+};
+
+static void __cpuinit print_cpu_msr(void)
+{
+        unsigned index;
+        u64 val;
+        int i;
+        unsigned index_min, index_max;
+
+        for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
+                index_min = msr_range_array[i].min;
+                index_max = msr_range_array[i].max;
+                for (index = index_min; index < index_max; index++) {
+                        if (rdmsrl_amd_safe(index, &val))
+                                continue;
+                        printk(KERN_INFO " MSR%08x: %016llx\n", index, val);
+                }
+        }
+}
+
+static int show_msr __cpuinitdata;
+static __init int setup_show_msr(char *arg)
+{
+        int num;
+
+        get_option(&arg, &num);
+
+        if (num > 0)
+                show_msr = num;
+        return 1;
+}
+__setup("show_msr=", setup_show_msr);
+
 void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
 {
         if (c->x86_model_id[0])
@@ -403,6 +482,14 @@ void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
                 printk(KERN_CONT " stepping %02x\n", c->x86_mask);
         else
                 printk(KERN_CONT "\n");
+
+#ifdef CONFIG_SMP
+        if (c->cpu_index < show_msr)
+                print_cpu_msr();
+#else
+        if (show_msr)
+                print_cpu_msr();
+#endif
 }
 
 static __init int setup_disablecpuid(char *arg)
@@ -493,17 +580,20 @@ void pda_init(int cpu)
                 /* others are initialized in smpboot.c */
                 pda->pcurrent = &init_task;
                 pda->irqstackptr = boot_cpu_stack;
+                pda->irqstackptr += IRQSTACKSIZE - 64;
         } else {
-                pda->irqstackptr = (char *)
-                        __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
-                if (!pda->irqstackptr)
-                        panic("cannot allocate irqstack for cpu %d", cpu);
+                if (!pda->irqstackptr) {
+                        pda->irqstackptr = (char *)
+                                __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
+                        if (!pda->irqstackptr)
+                                panic("cannot allocate irqstack for cpu %d",
+                                      cpu);
+                        pda->irqstackptr += IRQSTACKSIZE - 64;
+                }
 
                 if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)
                         pda->nodenumber = cpu_to_node(cpu);
         }
-
-        pda->irqstackptr += IRQSTACKSIZE-64;
 }
 
 char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ +
@@ -601,19 +691,22 @@ void __cpuinit cpu_init(void)
         /*
          * set up and load the per-CPU TSS
          */
-        for (v = 0; v < N_EXCEPTION_STACKS; v++) {
+        if (!orig_ist->ist[0]) {
                 static const unsigned int order[N_EXCEPTION_STACKS] = {
-                        [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,
-                        [DEBUG_STACK - 1] = DEBUG_STACK_ORDER
+                  [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,
+                  [DEBUG_STACK - 1] = DEBUG_STACK_ORDER
                 };
-                if (cpu) {
-                        estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);
-                        if (!estacks)
-                                panic("Cannot allocate exception stack %ld %d\n",
-                                      v, cpu);
+                for (v = 0; v < N_EXCEPTION_STACKS; v++) {
+                        if (cpu) {
+                                estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);
+                                if (!estacks)
+                                        panic("Cannot allocate exception "
+                                              "stack %ld %d\n", v, cpu);
+                        }
+                        estacks += PAGE_SIZE << order[v];
+                        orig_ist->ist[v] = t->x86_tss.ist[v] =
+                                        (unsigned long)estacks;
                 }
-                estacks += PAGE_SIZE << order[v];
-                orig_ist->ist[v] = t->x86_tss.ist[v] = (unsigned long)estacks;
         }
 
         t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);