Linux-2.6.12-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, 249 insertions, 0 deletions

diff --git a/arch/i386/kernel/cpu/amd.c b/arch/i386/kernel/cpu/amd.c
new file mode 100644
index 00000000000..ae94585d044
--- /dev/null
+++ b/arch/i386/kernel/cpu/amd.c
@@ -0,0 +1,249 @@
+#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);
+	detect_ht(c);
+
+#ifdef CONFIG_X86_HT
+	/* AMD dual core looks like HT but isn't really. Hide it from the
+	   scheduler. This works around problems with the domain scheduler.
+	   Also probably gives slightly better scheduling and disables
+	   SMT nice which is harmful on dual core.
+	   TBD tune the domain scheduler for dual core. */
+	if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
+		smp_num_siblings = 1;
+#endif
+
+	if (cpuid_eax(0x80000000) >= 0x80000008) {
+		c->x86_num_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
+		if (c->x86_num_cores & (c->x86_num_cores - 1))
+			c->x86_num_cores = 1;
+	}
+}
+
+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);