x86: make amd_64 have 32 bit code

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 247 insertions, 12 deletions

diff --git a/arch/x86/kernel/cpu/amd_64.c b/arch/x86/kernel/cpu/amd_64.c
index 1d83601e85ef..32e73520adf7 100644
--- a/arch/x86/kernel/cpu/amd_64.c
+++ b/arch/x86/kernel/cpu/amd_64.c
@@ -16,7 +16,171 @@
 
 #include "cpu.h"
 
-#ifdef CONFIG_NUMA
+#ifdef CONFIG_X86_32
+/*
+ *      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 __cpuinit init_amd_k5(struct cpuinfo_x86 *c)
+{
+/*
+ * 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);
+        }
+}
+
+
+static void __cpuinit init_amd_k6(struct cpuinfo_x86 *c)
+{
+        u32 l, h;
+        int mbytes = num_physpages >> (20-PAGE_SHIFT);
+
+        if (c->x86_model < 6) {
+                /* Based on AMD doc 20734R - June 2000 */
+                if (c->x86_model == 0) {
+                        clear_cpu_cap(c, X86_FEATURE_APIC);
+                        set_cpu_cap(c, X86_FEATURE_PGE);
+                }
+                return;
+        }
+
+        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;
+
+                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);
+                }
+                return;
+        }
+
+        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);
+                }
+
+                return;
+        }
+
+        if (c->x86_model == 10) {
+                /* AMD Geode LX is model 10 */
+                /* placeholder for any needed mods */
+                return;
+        }
+}
+
+static void __cpuinit init_amd_k7(struct cpuinfo_x86 *c)
+{
+        u32 l, h;
+
+        /*
+         * 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_cpu_cap(c, X86_FEATURE_XMM);
+                }
+        }
+
+        /*
+         * 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);
+                }
+        }
+
+        set_cpu_cap(c, X86_FEATURE_K7);
+}
+#endif
+
+#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
 static int __cpuinit nearby_node(int apicid)
 {
         int i, node;
@@ -41,7 +205,7 @@ static int __cpuinit nearby_node(int apicid)
  */
 static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c)
 {
-#ifdef CONFIG_SMP
+#ifdef CONFIG_X86_HT
         unsigned bits;
 
         bits = c->x86_coreid_bits;
@@ -55,7 +219,7 @@ static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c)
 
 static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
 {
-#ifdef CONFIG_NUMA
+#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
         int cpu = smp_processor_id();
         int node;
         unsigned apicid = hard_smp_processor_id();
@@ -91,7 +255,7 @@ static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
 
 static void __cpuinit early_init_amd_mc(struct cpuinfo_x86 *c)
 {
-#ifdef CONFIG_SMP
+#ifdef CONFIG_X86_HT
         unsigned bits, ecx;
 
         /* Multi core CPU? */
@@ -112,7 +276,6 @@ static void __cpuinit early_init_amd_mc(struct cpuinfo_x86 *c)
         }
 
         c->x86_coreid_bits = bits;
-
 #endif
 }
 
@@ -124,15 +287,21 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
         if (c->x86_power & (1<<8))
                 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
 
+#ifdef CONFIG_X86_64
         set_cpu_cap(c, X86_FEATURE_SYSCALL32);
+#else
+        /*  Set MTRR capability flag if appropriate */
+        if (c->x86 == 5)
+                if (c->x86_model == 13 || c->x86_model == 9 ||
+                    (c->x86_model == 8 && c->x86_mask >= 8))
+                        set_cpu_cap(c, X86_FEATURE_K6_MTRR);
+#endif
 }
 
 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 {
-        unsigned level;
-
 #ifdef CONFIG_SMP
-        unsigned long value;
+        unsigned long long value;
 
         /*
          * Disable TLB flush filter by setting HWCR.FFDIS on K8
@@ -142,26 +311,55 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
          * Errata 122 for all steppings (F+ have it disabled by default)
          */
         if (c->x86 == 0xf) {
-                rdmsrl(MSR_K8_HWCR, value);
+                rdmsrl(MSR_K7_HWCR, value);
                 value |= 1 << 6;
-                wrmsrl(MSR_K8_HWCR, value);
+                wrmsrl(MSR_K7_HWCR, value);
         }
 #endif
 
         early_init_amd(c);
 
-        /* Bit 31 in normal CPUID used for nonstandard 3DNow ID;
-           3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */
+        /*
+         * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
+         * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
+         */
         clear_cpu_cap(c, 0*32+31);
 
+#ifdef CONFIG_X86_64
         /* On C+ stepping K8 rep microcode works well for copy/memset */
         if (c->x86 == 0xf) {
+                u32 level;
+
                 level = cpuid_eax(1);
                 if((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
                         set_cpu_cap(c, X86_FEATURE_REP_GOOD);
         }
         if (c->x86 == 0x10 || c->x86 == 0x11)
                 set_cpu_cap(c, X86_FEATURE_REP_GOOD);
+#else
+
+        /*
+         *      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)
+         */
+
+        switch (c->x86) {
+        case 4:
+                init_amd_k5(c);
+                break;
+        case 5:
+                init_amd_k6(c);
+                break;
+        case 6: /* An Athlon/Duron */
+                init_amd_k7(c);
+                break;
+        }
+
+        /* K6s reports MCEs but don't actually have all the MSRs */
+        if (c->x86 < 6)
+                clear_cpu_cap(c, X86_FEATURE_MCE);
+#endif
 
         /* Enable workaround for FXSAVE leak */
         if (c->x86 >= 6)
@@ -176,6 +374,7 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
                         break;
                 }
         }
+
         display_cacheinfo(c);
 
         /* Multi core CPU? */
@@ -184,6 +383,10 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
                 srat_detect_node(c);
         }
 
+#ifdef CONFIG_X86_32
+        detect_ht(c);
+#endif
+
         if (c->extended_cpuid_level >= 0x80000006) {
                 if ((c->x86 >= 0x0f) && (cpuid_edx(0x80000006) & 0xf000))
                         num_cache_leaves = 4;
@@ -199,6 +402,7 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
                 set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
         }
 
+#ifdef CONFIG_X86_64
         if (c->x86 == 0x10) {
                 /* do this for boot cpu */
                 if (c == &boot_cpu_data)
@@ -225,11 +429,42 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
                         set_memory_4k((unsigned long)__va(tseg), 1);
                 }
         }
+#endif
+}
+
+#ifdef CONFIG_X86_32
+static unsigned int __cpuinit 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;
 }
+#endif
 
 static struct cpu_dev amd_cpu_dev __cpuinitdata = {
         .c_vendor       = "AMD",
         .c_ident        = { "AuthenticAMD" },
+#ifdef CONFIG_X86_32
+        .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_size_cache   = amd_size_cache,
+#endif
         .c_early_init   = early_init_amd,
         .c_init         = init_amd,
         .c_x86_vendor   = X86_VENDOR_AMD,