Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 476 insertions, 0 deletions

diff --git a/arch/i386/kernel/cpu/centaur.c b/arch/i386/kernel/cpu/centaur.c
new file mode 100644
index 0000000..394814e
--- /dev/null
+++ b/arch/i386/kernel/cpu/centaur.c
@@ -0,0 +1,476 @@
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <asm/processor.h>
+#include <asm/msr.h>
+#include <asm/e820.h>
+#include "cpu.h"
+
+#ifdef CONFIG_X86_OOSTORE
+
+static u32 __init power2(u32 x)
+{
+	u32 s=1;
+	while(s<=x)
+		s<<=1;
+	return s>>=1;
+}
+
+
+/*
+ *	Set up an actual MCR
+ */
+ 
+static void __init centaur_mcr_insert(int reg, u32 base, u32 size, int key)
+{
+	u32 lo, hi;
+	
+	hi = base & ~0xFFF;
+	lo = ~(size-1);		/* Size is a power of 2 so this makes a mask */
+	lo &= ~0xFFF;		/* Remove the ctrl value bits */
+	lo |= key;		/* Attribute we wish to set */
+	wrmsr(reg+MSR_IDT_MCR0, lo, hi);
+	mtrr_centaur_report_mcr(reg, lo, hi);	/* Tell the mtrr driver */
+}
+
+/*
+ *	Figure what we can cover with MCR's
+ *
+ *	Shortcut: We know you can't put 4Gig of RAM on a winchip
+ */
+
+static u32 __init ramtop(void)		/* 16388 */
+{
+	int i;
+	u32 top = 0;
+	u32 clip = 0xFFFFFFFFUL;
+	
+	for (i = 0; i < e820.nr_map; i++) {
+		unsigned long start, end;
+
+		if (e820.map[i].addr > 0xFFFFFFFFUL)
+			continue;
+		/*
+		 *	Don't MCR over reserved space. Ignore the ISA hole
+		 *	we frob around that catastrophy already
+		 */
+		 			
+		if (e820.map[i].type == E820_RESERVED)
+		{
+			if(e820.map[i].addr >= 0x100000UL && e820.map[i].addr < clip)
+				clip = e820.map[i].addr;
+			continue;
+		}
+		start = e820.map[i].addr;
+		end = e820.map[i].addr + e820.map[i].size;
+		if (start >= end)
+			continue;
+		if (end > top)
+			top = end;
+	}
+	/* Everything below 'top' should be RAM except for the ISA hole.
+	   Because of the limited MCR's we want to map NV/ACPI into our
+	   MCR range for gunk in RAM 
+	   
+	   Clip might cause us to MCR insufficient RAM but that is an
+	   acceptable failure mode and should only bite obscure boxes with
+	   a VESA hole at 15Mb
+	   
+	   The second case Clip sometimes kicks in is when the EBDA is marked
+	   as reserved. Again we fail safe with reasonable results
+	*/
+	
+	if(top>clip)
+		top=clip;
+		
+	return top;
+}
+
+/*
+ *	Compute a set of MCR's to give maximum coverage
+ */
+
+static int __init centaur_mcr_compute(int nr, int key)
+{
+	u32 mem = ramtop();
+	u32 root = power2(mem);
+	u32 base = root;
+	u32 top = root;
+	u32 floor = 0;
+	int ct = 0;
+	
+	while(ct<nr)
+	{
+		u32 fspace = 0;
+
+		/*
+		 *	Find the largest block we will fill going upwards
+		 */
+
+		u32 high = power2(mem-top);	
+
+		/*
+		 *	Find the largest block we will fill going downwards
+		 */
+
+		u32 low = base/2;
+
+		/*
+		 *	Don't fill below 1Mb going downwards as there
+		 *	is an ISA hole in the way.
+		 */		
+		 
+		if(base <= 1024*1024)
+			low = 0;
+			
+		/*
+		 *	See how much space we could cover by filling below
+		 *	the ISA hole
+		 */
+		 
+		if(floor == 0)
+			fspace = 512*1024;
+		else if(floor ==512*1024)
+			fspace = 128*1024;
+
+		/* And forget ROM space */
+		
+		/*
+		 *	Now install the largest coverage we get
+		 */
+		 
+		if(fspace > high && fspace > low)
+		{
+			centaur_mcr_insert(ct, floor, fspace, key);
+			floor += fspace;
+		}
+		else if(high > low)
+		{
+			centaur_mcr_insert(ct, top, high, key);
+			top += high;
+		}
+		else if(low > 0)
+		{
+			base -= low;
+			centaur_mcr_insert(ct, base, low, key);
+		}
+		else break;
+		ct++;
+	}
+	/*
+	 *	We loaded ct values. We now need to set the mask. The caller
+	 *	must do this bit.
+	 */
+	 
+	return ct;
+}
+
+static void __init centaur_create_optimal_mcr(void)
+{
+	int i;
+	/*
+	 *	Allocate up to 6 mcrs to mark as much of ram as possible
+	 *	as write combining and weak write ordered.
+	 *
+	 *	To experiment with: Linux never uses stack operations for 
+	 *	mmio spaces so we could globally enable stack operation wc
+	 *
+	 *	Load the registers with type 31 - full write combining, all
+	 *	writes weakly ordered.
+	 */
+	int used = centaur_mcr_compute(6, 31);
+
+	/*
+	 *	Wipe unused MCRs
+	 */
+	 
+	for(i=used;i<8;i++)
+		wrmsr(MSR_IDT_MCR0+i, 0, 0);
+}
+
+static void __init winchip2_create_optimal_mcr(void)
+{
+	u32 lo, hi;
+	int i;
+
+	/*
+	 *	Allocate up to 6 mcrs to mark as much of ram as possible
+	 *	as write combining, weak store ordered.
+	 *
+	 *	Load the registers with type 25
+	 *		8	-	weak write ordering
+	 *		16	-	weak read ordering
+	 *		1	-	write combining
+	 */
+
+	int used = centaur_mcr_compute(6, 25);
+	
+	/*
+	 *	Mark the registers we are using.
+	 */
+	 
+	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
+	for(i=0;i<used;i++)
+		lo|=1<<(9+i);
+	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
+	
+	/*
+	 *	Wipe unused MCRs
+	 */
+	 
+	for(i=used;i<8;i++)
+		wrmsr(MSR_IDT_MCR0+i, 0, 0);
+}
+
+/*
+ *	Handle the MCR key on the Winchip 2.
+ */
+
+static void __init winchip2_unprotect_mcr(void)
+{
+	u32 lo, hi;
+	u32 key;
+	
+	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
+	lo&=~0x1C0;	/* blank bits 8-6 */
+	key = (lo>>17) & 7;
+	lo |= key<<6;	/* replace with unlock key */
+	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
+}
+
+static void __init winchip2_protect_mcr(void)
+{
+	u32 lo, hi;
+	
+	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
+	lo&=~0x1C0;	/* blank bits 8-6 */
+	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
+}
+#endif /* CONFIG_X86_OOSTORE */
+
+#define ACE_PRESENT	(1 << 6)
+#define ACE_ENABLED	(1 << 7)
+#define ACE_FCR		(1 << 28)	/* MSR_VIA_FCR */
+
+#define RNG_PRESENT	(1 << 2)
+#define RNG_ENABLED	(1 << 3)
+#define RNG_ENABLE	(1 << 6)	/* MSR_VIA_RNG */
+
+static void __init init_c3(struct cpuinfo_x86 *c)
+{
+	u32  lo, hi;
+
+	/* Test for Centaur Extended Feature Flags presence */
+	if (cpuid_eax(0xC0000000) >= 0xC0000001) {
+		u32 tmp = cpuid_edx(0xC0000001);
+
+		/* enable ACE unit, if present and disabled */
+		if ((tmp & (ACE_PRESENT | ACE_ENABLED)) == ACE_PRESENT) {
+			rdmsr (MSR_VIA_FCR, lo, hi);
+			lo |= ACE_FCR;		/* enable ACE unit */
+			wrmsr (MSR_VIA_FCR, lo, hi);
+			printk(KERN_INFO "CPU: Enabled ACE h/w crypto\n");
+		}
+
+		/* enable RNG unit, if present and disabled */
+		if ((tmp & (RNG_PRESENT | RNG_ENABLED)) == RNG_PRESENT) {
+			rdmsr (MSR_VIA_RNG, lo, hi);
+			lo |= RNG_ENABLE;	/* enable RNG unit */
+			wrmsr (MSR_VIA_RNG, lo, hi);
+			printk(KERN_INFO "CPU: Enabled h/w RNG\n");
+		}
+
+		/* store Centaur Extended Feature Flags as
+		 * word 5 of the CPU capability bit array
+		 */
+		c->x86_capability[5] = cpuid_edx(0xC0000001);
+	}
+
+	/* Cyrix III family needs CX8 & PGE explicity enabled. */
+	if (c->x86_model >=6 && c->x86_model <= 9) {
+		rdmsr (MSR_VIA_FCR, lo, hi);
+		lo |= (1<<1 | 1<<7);
+		wrmsr (MSR_VIA_FCR, lo, hi);
+		set_bit(X86_FEATURE_CX8, c->x86_capability);
+	}
+
+	/* Before Nehemiah, the C3's had 3dNOW! */
+	if (c->x86_model >=6 && c->x86_model <9)
+		set_bit(X86_FEATURE_3DNOW, c->x86_capability);
+
+	get_model_name(c);
+	display_cacheinfo(c);
+}
+
+static void __init init_centaur(struct cpuinfo_x86 *c)
+{
+	enum {
+		ECX8=1<<1,
+		EIERRINT=1<<2,
+		DPM=1<<3,
+		DMCE=1<<4,
+		DSTPCLK=1<<5,
+		ELINEAR=1<<6,
+		DSMC=1<<7,
+		DTLOCK=1<<8,
+		EDCTLB=1<<8,
+		EMMX=1<<9,
+		DPDC=1<<11,
+		EBRPRED=1<<12,
+		DIC=1<<13,
+		DDC=1<<14,
+		DNA=1<<15,
+		ERETSTK=1<<16,
+		E2MMX=1<<19,
+		EAMD3D=1<<20,
+	};
+
+	char *name;
+	u32  fcr_set=0;
+	u32  fcr_clr=0;
+	u32  lo,hi,newlo;
+	u32  aa,bb,cc,dd;
+
+	/* 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);
+
+	switch (c->x86) {
+
+		case 5:
+			switch(c->x86_model) {
+			case 4:
+				name="C6";
+				fcr_set=ECX8|DSMC|EDCTLB|EMMX|ERETSTK;
+				fcr_clr=DPDC;
+				printk(KERN_NOTICE "Disabling bugged TSC.\n");
+				clear_bit(X86_FEATURE_TSC, c->x86_capability);
+#ifdef CONFIG_X86_OOSTORE
+				centaur_create_optimal_mcr();
+				/* Enable
+					write combining on non-stack, non-string
+					write combining on string, all types
+					weak write ordering 
+					
+				   The C6 original lacks weak read order 
+				   
+				   Note 0x120 is write only on Winchip 1 */
+				   
+				wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0);
+#endif				
+				break;
+			case 8:
+				switch(c->x86_mask) {
+				default:
+					name="2";
+					break;
+				case 7 ... 9:
+					name="2A";
+					break;
+				case 10 ... 15:
+					name="2B";
+					break;
+				}
+				fcr_set=ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|E2MMX|EAMD3D;
+				fcr_clr=DPDC;
+#ifdef CONFIG_X86_OOSTORE
+				winchip2_unprotect_mcr();
+				winchip2_create_optimal_mcr();
+				rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
+				/* Enable
+					write combining on non-stack, non-string
+					write combining on string, all types
+					weak write ordering 
+				*/
+				lo|=31;				
+				wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
+				winchip2_protect_mcr();
+#endif
+				break;
+			case 9:
+				name="3";
+				fcr_set=ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|E2MMX|EAMD3D;
+				fcr_clr=DPDC;
+#ifdef CONFIG_X86_OOSTORE
+				winchip2_unprotect_mcr();
+				winchip2_create_optimal_mcr();
+				rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
+				/* Enable
+					write combining on non-stack, non-string
+					write combining on string, all types
+					weak write ordering 
+				*/
+				lo|=31;				
+				wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
+				winchip2_protect_mcr();
+#endif
+				break;
+			case 10:
+				name="4";
+				/* no info on the WC4 yet */
+				break;
+			default:
+				name="??";
+			}
+
+			rdmsr(MSR_IDT_FCR1, lo, hi);
+			newlo=(lo|fcr_set) & (~fcr_clr);
+
+			if (newlo!=lo) {
+				printk(KERN_INFO "Centaur FCR was 0x%X now 0x%X\n", lo, newlo );
+				wrmsr(MSR_IDT_FCR1, newlo, hi );
+			} else {
+				printk(KERN_INFO "Centaur FCR is 0x%X\n",lo);
+			}
+			/* Emulate MTRRs using Centaur's MCR. */
+			set_bit(X86_FEATURE_CENTAUR_MCR, c->x86_capability);
+			/* Report CX8 */
+			set_bit(X86_FEATURE_CX8, c->x86_capability);
+			/* Set 3DNow! on Winchip 2 and above. */
+			if (c->x86_model >=8)
+				set_bit(X86_FEATURE_3DNOW, c->x86_capability);
+			/* See if we can find out some more. */
+			if ( cpuid_eax(0x80000000) >= 0x80000005 ) {
+				/* Yes, we can. */
+				cpuid(0x80000005,&aa,&bb,&cc,&dd);
+				/* Add L1 data and code cache sizes. */
+				c->x86_cache_size = (cc>>24)+(dd>>24);
+			}
+			sprintf( c->x86_model_id, "WinChip %s", name );
+			break;
+
+		case 6:
+			init_c3(c);
+			break;
+	}
+}
+
+static unsigned int centaur_size_cache(struct cpuinfo_x86 * c, unsigned int size)
+{
+	/* VIA C3 CPUs (670-68F) need further shifting. */
+	if ((c->x86 == 6) && ((c->x86_model == 7) || (c->x86_model == 8)))
+		size >>= 8;
+
+	/* VIA also screwed up Nehemiah stepping 1, and made
+	   it return '65KB' instead of '64KB'
+	   - Note, it seems this may only be in engineering samples. */
+	if ((c->x86==6) && (c->x86_model==9) && (c->x86_mask==1) && (size==65))
+		size -=1;
+
+	return size;
+}
+
+static struct cpu_dev centaur_cpu_dev __initdata = {
+	.c_vendor	= "Centaur",
+	.c_ident	= { "CentaurHauls" },
+	.c_init		= init_centaur,
+	.c_size_cache	= centaur_size_cache,
+};
+
+int __init centaur_init_cpu(void)
+{
+	cpu_devs[X86_VENDOR_CENTAUR] = &centaur_cpu_dev;
+	return 0;
+}
+
+//early_arch_initcall(centaur_init_cpu);