#include <linux/init.h>#include <linux/bitops.h>#include <linux/mm.h>#include <asm/io.h>#include <asm/processor.h>#include "cpu.h"/* *	B step AMD K6 before B 9730xxxx have hardware bugs that can cause *	misexecution of code under Linux. Owners of such processors should *	contact AMD for precise details and a CPU swap. * *	See	http://www.multimania.com/poulot/k6bug.html *		http://www.amd.com/K6/k6docs/revgd.html * *	The following test is erm.. interesting. AMD neglected to up *	the chip setting when fixing the bug but they also tweaked some *	performance at the same time.. */ extern void vide(void);__asm__(".align 4\nvide: ret");static void __init init_amd(struct cpuinfo_x86 *c){	u32 l, h;	int mbytes = num_physpages >> (20-PAGE_SHIFT);	int r;	/*	 *	FIXME: We should handle the K5 here. Set up the write	 *	range and also turn on MSR 83 bits 4 and 31 (write alloc,	 *	no bus pipeline)	 */	/* Bit 31 in normal CPUID used for nonstandard 3DNow ID;	   3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */	clear_bit(0*32+31, c->x86_capability);		r = get_model_name(c);	switch(c->x86)	{		case 4:		/*		 * General Systems BIOSen alias the cpu frequency registers		 * of the Elan at 0x000df000. Unfortuantly, one of the Linux		 * drivers subsequently pokes it, and changes the CPU speed.		 * Workaround : Remove the unneeded alias.		 */#define CBAR		(0xfffc) /* Configuration Base Address  (32-bit) */#define CBAR_ENB	(0x80000000)#define CBAR_KEY	(0X000000CB)			if (c->x86_model==9 || c->x86_model == 10) {				if (inl (CBAR) & CBAR_ENB)					outl (0 | CBAR_KEY, CBAR);			}			break;		case 5:			if( c->x86_model < 6 )			{				/* Based on AMD doc 20734R - June 2000 */				if ( c->x86_model == 0 ) {					clear_bit(X86_FEATURE_APIC, c->x86_capability);					set_bit(X86_FEATURE_PGE, c->x86_capability);				}				break;			}						if ( c->x86_model == 6 && c->x86_mask == 1 ) {				const int K6_BUG_LOOP = 1000000;				int n;				void (*f_vide)(void);				unsigned long d, d2;								printk(KERN_INFO "AMD K6 stepping B detected - ");								/*				 * It looks like AMD fixed the 2.6.2 bug and improved indirect 				 * calls at the same time.				 */				n = K6_BUG_LOOP;				f_vide = vide;				rdtscl(d);				while (n--) 					f_vide();				rdtscl(d2);				d = d2-d;								/* Knock these two lines out if it debugs out ok */				printk(KERN_INFO "AMD K6 stepping B detected - ");				/* -- cut here -- */				if (d > 20*K6_BUG_LOOP) 					printk("system stability may be impaired when more than 32 MB are used.\n");				else 					printk("probably OK (after B9730xxxx).\n");				printk(KERN_INFO "Please see http://membres.lycos.fr/poulot/k6bug.html\n");			}			/* K6 with old style WHCR */			if (c->x86_model < 8 ||			   (c->x86_model== 8 && c->x86_mask < 8)) {				/* We can only write allocate on the low 508Mb */				if(mbytes>508)					mbytes=508;				rdmsr(MSR_K6_WHCR, l, h);				if ((l&0x0000FFFF)==0) {					unsigned long flags;					l=(1<<0)|((mbytes/4)<<1);					local_irq_save(flags);					wbinvd();					wrmsr(MSR_K6_WHCR, l, h);					local_irq_restore(flags);					printk(KERN_INFO "Enabling old style K6 write allocation for %d Mb\n",						mbytes);				}				break;			}			if ((c->x86_model == 8 && c->x86_mask >7) ||			     c->x86_model == 9 || c->x86_model == 13) {				/* The more serious chips .. */				if(mbytes>4092)					mbytes=4092;				rdmsr(MSR_K6_WHCR, l, h);				if ((l&0xFFFF0000)==0) {					unsigned long flags;					l=((mbytes>>2)<<22)|(1<<16);					local_irq_save(flags);					wbinvd();					wrmsr(MSR_K6_WHCR, l, h);					local_irq_restore(flags);					printk(KERN_INFO "Enabling new style K6 write allocation for %d Mb\n",						mbytes);				}				/*  Set MTRR capability flag if appropriate */				if (c->x86_model == 13 || c->x86_model == 9 ||				   (c->x86_model == 8 && c->x86_mask >= 8))					set_bit(X86_FEATURE_K6_MTRR, c->x86_capability);				break;			}			break;		case 6: /* An Athlon/Duron */ 			/* Bit 15 of Athlon specific MSR 15, needs to be 0 			 * to enable SSE on Palomino/Morgan/Barton CPU's.			 * If the BIOS didn't enable it already, enable it here.			 */			if (c->x86_model >= 6 && c->x86_model <= 10) {				if (!cpu_has(c, X86_FEATURE_XMM)) {					printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");					rdmsr(MSR_K7_HWCR, l, h);					l &= ~0x00008000;					wrmsr(MSR_K7_HWCR, l, h);					set_bit(X86_FEATURE_XMM, c->x86_capability);				}			}			/* It's been determined by AMD that Athlons since model 8 stepping 1			 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx			 * As per AMD technical note 27212 0.2			 */			if ((c->x86_model == 8 && c->x86_mask>=1) || (c->x86_model > 8)) {				rdmsr(MSR_K7_CLK_CTL, l, h);				if ((l & 0xfff00000) != 0x20000000) {					printk ("CPU: CLK_CTL MSR was %x. Reprogramming to %x\n", l,						((l & 0x000fffff)|0x20000000));					wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);				}			}			break;	}	switch (c->x86) {	case 15:		set_bit(X86_FEATURE_K8, c->x86_capability);		break;	case 6:		set_bit(X86_FEATURE_K7, c->x86_capability); 		break;	}	display_cacheinfo(c);}static unsigned int amd_size_cache(struct cpuinfo_x86 * c, unsigned int size){	/* AMD errata T13 (order #21922) */	if ((c->x86 == 6)) {		if (c->x86_model == 3 && c->x86_mask == 0)	/* Duron Rev A0 */			size = 64;		if (c->x86_model == 4 &&		    (c->x86_mask==0 || c->x86_mask==1))	/* Tbird rev A1/A2 */			size = 256;	}	return size;}static struct cpu_dev amd_cpu_dev __initdata = {	.c_vendor	= "AMD",	.c_ident 	= { "AuthenticAMD" },	.c_models = {		{ .vendor = X86_VENDOR_AMD, .family = 4, .model_names =		  {			  [3] = "486 DX/2",			  [7] = "486 DX/2-WB",			  [8] = "486 DX/4", 			  [9] = "486 DX/4-WB", 			  [14] = "Am5x86-WT",			  [15] = "Am5x86-WB" 		  }		},	},	.c_init		= init_amd,	.c_identify	= generic_identify,	.c_size_cache	= amd_size_cache,};int __init amd_init_cpu(void){	cpu_devs[X86_VENDOR_AMD] = &amd_cpu_dev;	return 0;}//early_arch_initcall(amd_init_cpu);