[PATCH] x86: more asm cleanups

Some more assembler cleanups I noticed along the way.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/cpu/intel.c

@@ -82,16 +82,13 @@ static void __devinit Intel_errata_workarounds(struct cpuinfo_x86 *c)
  */
 static int __devinit num_cpu_cores(struct cpuinfo_x86 *c)
 {
-	unsigned int eax;
+	unsigned int eax, ebx, ecx, edx;
 
 	if (c->cpuid_level < 4)
 		return 1;
 
-	__asm__("cpuid"
+	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
-		: "=a" (eax)
+	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
-		: "0" (4), "c" (0)
-		: "bx", "dx");
-
 	if (eax & 0x1f)
 		return ((eax >> 26) + 1);
 	else

arch/i386/kernel/crash.c

@@ -153,7 +153,7 @@ static int crash_nmi_callback(struct pt_regs *regs, int cpu)
 	disable_local_APIC();
 	atomic_dec(&waiting_for_crash_ipi);
 	/* Assume hlt works */
-	__asm__("hlt");
+	halt();
 	for(;;);
 
 	return 1;

arch/i386/kernel/machine_kexec.c

@@ -93,10 +93,7 @@ static void set_idt(void *newidt, __u16 limit)
 	curidt.size    = limit;
 	curidt.address = (unsigned long)newidt;
 
-	__asm__ __volatile__ (
+	load_idt(&curidt);
-		"lidtl %0\n"
-		: : "m" (curidt)
-		);
 };
 
 
@@ -108,10 +105,7 @@ static void set_gdt(void *newgdt, __u16 limit)
 	curgdt.size    = limit;
 	curgdt.address = (unsigned long)newgdt;
 
-	__asm__ __volatile__ (
+	load_gdt(&curgdt);
-		"lgdtl %0\n"
-		: : "m" (curgdt)
-		);
 };
 
 static void load_segments(void)

arch/i386/kernel/msr.c

@@ -46,23 +46,13 @@
 
 static struct class *msr_class;
 
-/* Note: "err" is handled in a funny way below.  Otherwise one version
-   of gcc or another breaks. */
-
 static inline int wrmsr_eio(u32 reg, u32 eax, u32 edx)
 {
 	int err;
 
-	asm volatile ("1:	wrmsr\n"
+	err = wrmsr_safe(reg, eax, edx);
-		      "2:\n"
+	if (err)
-		      ".section .fixup,\"ax\"\n"
+		err = -EIO;
-		      "3:	movl %4,%0\n"
-		      "	jmp 2b\n"
-		      ".previous\n"
-		      ".section __ex_table,\"a\"\n"
-		      "	.align 4\n" "	.long 1b,3b\n" ".previous":"=&bDS" (err)
-		      :"a"(eax), "d"(edx), "c"(reg), "i"(-EIO), "0"(0));
-
 	return err;
 }
 
@@ -70,18 +60,9 @@ static inline int rdmsr_eio(u32 reg, u32 *eax, u32 *edx)
 {
 	int err;
 
-	asm volatile ("1:	rdmsr\n"
+	err = rdmsr_safe(reg, eax, edx);
-		      "2:\n"
+	if (err)
-		      ".section .fixup,\"ax\"\n"
+		err = -EIO;
-		      "3:	movl %4,%0\n"
-		      "	jmp 2b\n"
-		      ".previous\n"
-		      ".section __ex_table,\"a\"\n"
-		      "	.align 4\n"
-		      "	.long 1b,3b\n"
-		      ".previous":"=&bDS" (err), "=a"(*eax), "=d"(*edx)
-		      :"c"(reg), "i"(-EIO), "0"(0));
-
 	return err;
 }
 

arch/i386/kernel/process.c

@@ -164,7 +164,7 @@ static inline void play_dead(void)
 	 */
 	local_irq_disable();
 	while (1)
-		__asm__ __volatile__("hlt":::"memory");
+		halt();
 }
 #else
 static inline void play_dead(void)

arch/i386/mach-voyager/voyager_basic.c

@@ -234,10 +234,9 @@ voyager_power_off(void)
 #endif
 	}
 	/* and wait for it to happen */
-	for(;;) {
+	local_irq_disable();
-		__asm("cli");
+	for(;;)
-		__asm("hlt");
+		halt();
-	}
 }
 
 /* copied from process.c */
@@ -278,10 +277,9 @@ machine_restart(char *cmd)
 		outb(basebd | 0x08, VOYAGER_MC_SETUP);
 		outb(0x02, catbase + 0x21);
 	}
-	for(;;) {
+	local_irq_disable();
-		asm("cli");
+	for(;;)
-		asm("hlt");
+		halt();
-	}
 }
 
 void

arch/i386/mach-voyager/voyager_smp.c

@@ -1015,7 +1015,7 @@ smp_stop_cpu_function(void *dummy)
 	cpu_clear(smp_processor_id(), cpu_online_map);
 	local_irq_disable();
 	for(;;)
-	       __asm__("hlt");
+		halt();
 }
 
 static DEFINE_SPINLOCK(call_lock);

include/asm-i386/msr.h

@@ -47,6 +47,21 @@ static inline void wrmsrl (unsigned long msr, unsigned long long val)
 		     : "c" (msr), "0" (a), "d" (b), "i" (-EFAULT));\
 	ret__; })
 
+/* rdmsr with exception handling */
+#define rdmsr_safe(msr,a,b) ({ int ret__;						\
+	asm volatile("2: rdmsr ; xorl %0,%0\n"						\
+		     "1:\n\t"								\
+		     ".section .fixup,\"ax\"\n\t"					\
+		     "3:  movl %4,%0 ; jmp 1b\n\t"					\
+		     ".previous\n\t"							\
+ 		     ".section __ex_table,\"a\"\n"					\
+		     "   .align 4\n\t"							\
+		     "   .long 	2b,3b\n\t"						\
+		     ".previous"							\
+		     : "=r" (ret__), "=a" (*(a)), "=d" (*(b))				\
+		     : "c" (msr), "i" (-EFAULT));\
+	ret__; })
+
 #define rdtsc(low,high) \
      __asm__ __volatile__("rdtsc" : "=a" (low), "=d" (high))