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!
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] = ¢aur_cpu_dev;
+ return 0;
+}
+
+//early_arch_initcall(centaur_init_cpu);