x86_64: printout msr -v2

commandline show_msr=1 for bsp, show_msr=32 for all 32 cpus.

[ mingo@elte.hu: added documentation ]

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

5 files changed, 93 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 47e7d8794fc6..8679e80b9fc4 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1852,6 +1852,12 @@ and is between 256 and 4096 characters. It is defined in the file
         shapers=        [NET]
                         Maximal number of shapers.
 
+        show_msr=       [x86] show boot-time MSR settings
+                        Format: { <integer> }
+                        Show boot-time (BIOS-initialized) MSR settings.
+                        The parameter means the number of CPUs to show,
+                        for example 1 means boot CPU only.
+
         sim710=         [SCSI,HW]
                         See header of drivers/scsi/sim710.c.
 
diff --git a/arch/x86/kernel/cpu/common_64.c b/arch/x86/kernel/cpu/common_64.c
index dd6e3f15017e..bca2d6980e82 100644
--- a/arch/x86/kernel/cpu/common_64.c
+++ b/arch/x86/kernel/cpu/common_64.c
@@ -394,6 +394,49 @@ 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 +446,14 @@ 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)
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 94da4d52d798..c6044682e1e7 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -330,6 +330,7 @@ struct pv_cpu_ops pv_cpu_ops = {
 #endif
         .wbinvd = native_wbinvd,
         .read_msr = native_read_msr_safe,
+        .read_msr_amd = native_read_msr_amd_safe,
         .write_msr = native_write_msr_safe,
         .read_tsc = native_read_tsc,
         .read_pmc = native_read_pmc,
diff --git a/include/asm-x86/msr.h b/include/asm-x86/msr.h
index ca110ee73f07..a30e586df933 100644
--- a/include/asm-x86/msr.h
+++ b/include/asm-x86/msr.h
@@ -63,6 +63,22 @@ static inline unsigned long long native_read_msr_safe(unsigned int msr,
         return EAX_EDX_VAL(val, low, high);
 }
 
+static inline unsigned long long native_read_msr_amd_safe(unsigned int msr,
+                                                      int *err)
+{
+        DECLARE_ARGS(val, low, high);
+
+        asm volatile("2: rdmsr ; xor %0,%0\n"
+                     "1:\n\t"
+                     ".section .fixup,\"ax\"\n\t"
+                     "3:  mov %3,%0 ; jmp 1b\n\t"
+                     ".previous\n\t"
+                     _ASM_EXTABLE(2b, 3b)
+                     : "=r" (*err), EAX_EDX_RET(val, low, high)
+                     : "c" (msr), "D" (0x9c5a203a), "i" (-EFAULT));
+        return EAX_EDX_VAL(val, low, high);
+}
+
 static inline void native_write_msr(unsigned int msr,
                                     unsigned low, unsigned high)
 {
@@ -158,6 +174,13 @@ static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
         *p = native_read_msr_safe(msr, &err);
         return err;
 }
+static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
+{
+        int err;
+
+        *p = native_read_msr_amd_safe(msr, &err);
+        return err;
+}
 
 #define rdtscl(low)                                             \
         ((low) = (u32)native_read_tsc())
diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h
index fbbde93f12d6..d5cfc5e3eb5b 100644
--- a/include/asm-x86/paravirt.h
+++ b/include/asm-x86/paravirt.h
@@ -137,6 +137,7 @@ struct pv_cpu_ops {
 
         /* MSR, PMC and TSR operations.
            err = 0/-EFAULT.  wrmsr returns 0/-EFAULT. */
+        u64 (*read_msr_amd)(unsigned int msr, int *err);
         u64 (*read_msr)(unsigned int msr, int *err);
         int (*write_msr)(unsigned int msr, unsigned low, unsigned high);
 
@@ -726,6 +727,10 @@ static inline u64 paravirt_read_msr(unsigned msr, int *err)
 {
         return PVOP_CALL2(u64, pv_cpu_ops.read_msr, msr, err);
 }
+static inline u64 paravirt_read_msr_amd(unsigned msr, int *err)
+{
+        return PVOP_CALL2(u64, pv_cpu_ops.read_msr_amd, msr, err);
+}
 static inline int paravirt_write_msr(unsigned msr, unsigned low, unsigned high)
 {
         return PVOP_CALL3(int, pv_cpu_ops.write_msr, msr, low, high);
@@ -771,6 +776,13 @@ static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
         *p = paravirt_read_msr(msr, &err);
         return err;
 }
+static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
+{
+        int err;
+
+        *p = paravirt_read_msr_amd(msr, &err);
+        return err;
+}
 
 static inline u64 paravirt_read_tsc(void)
 {