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>

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.
 

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)

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,

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())

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)
 {