[PATCH] Fix x86-64 loose ends

 - Make MTRR driver compatible with 2.4/x86-64 again.  This fixes an
   endless loop in the XFree86 4.3pre server.
 - Fix the boot code that rejected earlier: rewrote early CPU detection
   and SSE is forced now
 - Always force inlining in vsyscalls

arch/x86_64/boot/compressed/misc.c

@@ -329,84 +329,46 @@ void close_output_buffer_if_we_run_high(struct moveparams *mv)
 
 void check_cpu(void)
 {
-	int res = 0;
-        int tmp, flags;
-
-	asm volatile( " \n\
-	movl $3,%%edx		# at least 386 \n\
-	pushfl			# push EFLAGS \n\
-	popl %%eax		# get EFLAGS \n\
-	movl %%eax,%%ecx		# save original EFLAGS \n\
-	xorl $0x40000,%%eax	# flip AC bit in EFLAGS \n\
-	pushl %%eax		# copy to EFLAGS \n\
-	popfl			# set EFLAGS \n\
-	pushfl			# get new EFLAGS \n\
-	popl %%eax		# put it in eax \n\
-	xorl %%ecx,%%eax		# change in flags \n\
-	andl $0x40000,%%eax	# check if AC bit changed \n\
-	je 1f \n\
-\n\
-	movl $4,%%edx		# at least 486 \n\
-	movl %%ecx,%%eax \n\
-	xorl $0x200000,%%eax	# check ID flag \n\
-	pushl %%eax \n\
-	popfl			# if we are on a straight 486DX, SX, or \n\
-	pushfl			# 487SX we can't change it \n\
-	popl %%eax \n\
-	xorl %%ecx,%%eax \n\
-	pushl %%ecx		# restore original EFLAGS \n\
-	popfl \n\
-	andl $0x200000,%%eax \n\
-	je 1f \n\
-\n\
-	/* get vendor info */ \n\
-#	xorl %%eax,%%eax			# call CPUID with 0 -> return vendor ID \n\
-#	cpuid \n\
-#	movl $5, %%edx \n\
-#	cmpl $0x41757468,%%ebx		# check thats amd \n\
-#	jne 1f \n\
-\n\
-	mov $0x80000000,%%eax		# Is extended cpuid supported?\n\
-	cpuid\n\
-	test $0x80000000,%%eax\n\
-	movl $5, %%edx \n\
-	jz 1f\n\
-\n\
-	movl $0x80000001,%%eax \n\
-	cpuid \n\
-	andl $0x20000000,%%edx \n\
-	movl $6, %%edx \n\
-	jz 1f \n\
-\n\
-	movl $7, %%edx \n\
-1:" : "=d" (res) : : "eax", "ebx", "ecx" );
-
-	switch (res) {
-	case 3: puts( "386" );
-		break;
-	case 4: puts( "486" );
-		break;
-	case 5: puts( "no extended cpuid" );
-		break;
-	case 6: puts( "non-64bit 586+" );
-		break;
-	case 7: puts( "64bit" );
-		break;
-	default:puts( "internal error" );
-		break;
-	}
-	if (res !=7)
-		error( "Sorry, your CPU is not capable of running 64-bit kernel." );
+	unsigned before, after, flags;
+	unsigned a,b,c,d;
+	int isamd; 
+
+	/* check if the CPU supports CPUID. This is done by testing if the CPU
+	   supports changing the ID bit (21) in EFLAGS. */
+	asm("pushfl ; "		
+	    "popl %0 ; "		/* get EFLAGS */	
+	    "movl  %0,%1 ; "
+	    "xorl  $(1<<21),%0 ; "	/* toggle bit 21 */ 
+	    "pushl %0 ; " 
+	    "popfl ; "
+	    "pushfl ; " 		/* get EFLAGS again */
+	    "popl %0 " : "=r" (after), "=r" (before));
+	if (before == after) 
+		error("Your CPU doesn't support CPUID.");
+
+	/* check if it supports AMD extended cpuid reporting */
+	asm("cpuid" : "=a" (a), "=b" (b), "=c" (c), "=d" (d) : "0" (0x80000000));
+
+	if (a < 0x80000001)
+		error("Your CPU doesn't support AMD extended CPUIDs.");
+
+	/* AuthenticAMD */
+	isamd = (b == 0x68747541) && (d == 0x69746e65) && (c == 0x444d4163);
+
         /* check required feature flags */ 
         /* see http://www.x86-64.org/lists/discuss/msg02971.html */
 #define REQUIRED_MASK1 ((1<<0)|(1<<3)|(1<<4)|(1<<5)|(1<<6)|(1<<8)|(1<<11)| \
                                            (1<<13)|(1<<15)|(1<<24))
         
-        asm("cpuid" : "=d" (flags), "=a" (tmp) : "1" (0x80000001) : "ebx", "ecx"); 
+	asm("cpuid" : "=d" (flags), "=a" (a) : "1" (0x80000001) : "ebx", "ecx"); 
         flags &= REQUIRED_MASK1;
         flags ^= REQUIRED_MASK1; 
+	if (flags & (1<<9)) {
+		puts("WARNING: non APIC mode for long mode kernel is untested.");
+		puts("In case of trouble use 32bit kernel or enable APIC.");
+	}
         if (flags & (1<<0))
-                error("CPU misses x87"); 
+		error("CPU misses x87 FPU"); 
         if (flags & (1<<3)) 
                 error("CPU doesn't support page size extension (PSE)");
         if (flags & (1<<4))
@@ -425,11 +387,23 @@ void check_cpu(void)
                 error("CPU doesn't support CMOV"); 
         if (flags & (1<<24))
                 error("CPU doesn't support FXSAVE/FXRSTOR"); 
-
-#define REQUIRED_MASK2 ((1<<25)|(1<<26))        
-        asm("cpuid" : "=d" (flags), "=a" (tmp) : "1" (1) : "ebx", "ecx"); 
-        flags &= REQUIRED_MASK2; 
-        flags ^= REQUIRED_MASK2; 
+	if (flags & (1<<29))
+		error("CPU doesn't support long mode");
+	
+#define SSE_MASK ((1<<25)|(1<<26))	
+	asm("cpuid" : "=d" (flags), "=a" (a) : "1" (1) : "ebx", "ecx"); 
+	if ((flags & SSE_MASK) != SSE_MASK && isamd) {
+		/* Only try this on AMD CPUs. */
+		/* Enable SSE in HWCFG MSR */
+		asm volatile("rdmsr" : "=d" (d), "=a" (flags) : "c" (0xc0010015));
+		flags &= ~(1<<15);
+		asm volatile("wrmsr" :: "d" (d), "a" (flags), "c" (0xc0010015));
+	} 
+
+	/* Try again */
+	asm("cpuid" : "=d" (flags), "=a" (a) : "1" (1) : "ebx", "ecx"); 
+	flags &= SSE_MASK;
+	flags ^= SSE_MASK;
         if (flags & (1<<25))
                 error("CPU doesn't support SSE1");
         if (flags & (1<<26))

arch/x86_64/kernel/vsyscall.c

@@ -51,13 +51,14 @@
 #include <asm/errno.h>
 
 #define __vsyscall(nr) __attribute__ ((unused,__section__(".vsyscall_" #nr)))
+#define force_inline __attribute__((always_inline)) inline
 
 int __sysctl_vsyscall __section_sysctl_vsyscall = 1;
 seqlock_t __xtime_lock __section_xtime_lock = SEQLOCK_UNLOCKED;
 
 #include <asm/unistd.h>
 
-static inline void timeval_normalize(struct timeval * tv)
+static force_inline void timeval_normalize(struct timeval * tv)
 {
 	time_t __sec;
 
@@ -69,7 +70,7 @@ static inline void timeval_normalize(struct timeval * tv)
 	}
 }
 
-static inline void do_vgettimeofday(struct timeval * tv)
+static force_inline void do_vgettimeofday(struct timeval * tv)
 {
 	long sequence, t;
 	unsigned long sec, usec;
@@ -91,12 +92,12 @@ static inline void do_vgettimeofday(struct timeval * tv)
 }
 
 /* RED-PEN may want to readd seq locking, but then the variable should be write-once. */
-static inline void do_get_tz(struct timezone * tz)
+static force_inline void do_get_tz(struct timezone * tz)
 {
 		*tz = __sys_tz;
 }
 
-static inline int gettimeofday(struct timeval *tv, struct timezone *tz)
+static force_inline int gettimeofday(struct timeval *tv, struct timezone *tz)
 {
 	int ret;
 	asm volatile("syscall" 

include/asm-x86_64/mtrr.h

@@ -35,11 +35,15 @@ struct mtrr_sentry
     unsigned int type;     /*  Type of region   */
 };
 
+/* Warning: this structure has a different order from i386
+   on x86-64. The 32bit emulation code takes care of that.
+   But you need to use this for 64bit, otherwise your X server
+   will break. */
 struct mtrr_gentry
 {
     unsigned long base;    /*  Base address     */
-    unsigned int regnum;   /*  Register number  */
     unsigned int size;    /*  Size of region   */
+    unsigned int regnum;   /*  Register number  */
     unsigned int type;     /*  Type of region   */
 };