[CPUFREQ] Longhaul - Introduce Nehemiah C

Looks like some time ago I introduced a bug to Longhaul.
I had report that 9x133Mhz CPU is seen as 5x133MHz. So I
changed multipliers table. That was a mistake. According to
documentation table was correct. So only way to avoid 5 or 9
dilema is not use MaxMHzBR for PowerSaver 1.0. One code that
works on all processors. To do it I need also separate flag for
Nehemiah C (min = x4.0) and Nehemiah (min = x5.0).

Signed-off-by: Rafał Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>

1 files changed, 28 insertions, 45 deletions

diff --git a/arch/i386/kernel/cpu/cpufreq/longhaul.c b/arch/i386/kernel/cpu/cpufreq/longhaul.c
index b679aaf0c6b4..849a6dfdfea8 100644
--- a/arch/i386/kernel/cpu/cpufreq/longhaul.c
+++ b/arch/i386/kernel/cpu/cpufreq/longhaul.c
@@ -51,6 +51,7 @@
 #define CPU_EZRA        3
 #define CPU_EZRA_T      4
 #define CPU_NEHEMIAH    5
+#define CPU_NEHEMIAH_C  6
 
 /* Flags */
 #define USE_ACPI_C3             (1 << 1)
@@ -349,67 +350,47 @@ static int guess_fsb(int mult)
 
 static int __init longhaul_get_ranges(void)
 {
-        unsigned long invalue;
-        unsigned int ezra_t_multipliers[32]= {
-                        90,  30,  40, 100,  55,  35,  45,  95,
-                        50,  70,  80,  60, 120,  75,  85,  65,
-                        -1, 110, 120,  -1, 135, 115, 125, 105,
-                        130, 150, 160, 140,  -1, 155,  -1, 145 };
         unsigned int j, k = 0;
-        union msr_longhaul longhaul;
-        int mult = 0;
+        int mult;
 
+        /* Get current frequency */
+        mult = longhaul_get_cpu_mult();
+        if (mult == -1) {
+                printk(KERN_INFO PFX "Invalid (reserved) multiplier!\n");
+                return -EINVAL;
+        }
+        fsb = guess_fsb(mult);
+        if (fsb == 0) {
+                printk(KERN_INFO PFX "Invalid (reserved) FSB!\n");
+                return -EINVAL;
+        }
+        /* Get max multiplier - as we always did.
+         * Longhaul MSR is usefull only when voltage scaling is enabled.
+         * C3 is booting at max anyway. */
+        maxmult = mult;
+        /* Get min multiplier */
         switch (longhaul_version) {
         case TYPE_LONGHAUL_V1:
         case TYPE_LONGHAUL_V2:
-                /* Ugh, Longhaul v1 didn't have the min/max MSRs.
-                   Assume min=3.0x & max = whatever we booted at. */
                 minmult = 30;
-                maxmult = mult = longhaul_get_cpu_mult();
                 break;
 
         case TYPE_POWERSAVER:
                 /* Ezra-T */
-                if (cpu_model==CPU_EZRA_T) {
+                if (cpu_model == CPU_EZRA_T)
                         minmult = 30;
-                        rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);
-                        invalue = longhaul.bits.MaxMHzBR;
-                        if (longhaul.bits.MaxMHzBR4)
-                                invalue += 16;
-                        maxmult = mult = ezra_t_multipliers[invalue];
-                        break;
-                }
-
                 /* Nehemiah */
-                if (cpu_model==CPU_NEHEMIAH) {
-                        rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);
-
-                        /*
-                         * TODO: This code works, but raises a lot of questions.
-                         * - Some Nehemiah's seem to have broken Min/MaxMHzBR's.
-                         *   We get around this by using a hardcoded multiplier of 4.0x
-                         *   for the minimimum speed, and the speed we booted up at for the max.
-                         *   This is done in longhaul_get_cpu_mult() by reading the EBLCR register.
-                         * - According to some VIA documentation EBLCR is only
-                         *   in pre-Nehemiah C3s. How this still works is a mystery.
-                         *   We're possibly using something undocumented and unsupported,
-                         *   But it works, so we don't grumble.
-                         */
-                        minmult=40;
-                        maxmult = mult = longhaul_get_cpu_mult();
-                        break;
-                }
+                else if (cpu_model == CPU_NEHEMIAH)
+                        minmult = 50;
+                /* Nehemiah C */
+                else if (cpu_model == CPU_NEHEMIAH_C)
+                        minmult = 40;
+                break;
         }
-        fsb = guess_fsb(mult);
 
         dprintk ("MinMult:%d.%dx MaxMult:%d.%dx\n",
                  minmult/10, minmult%10, maxmult/10, maxmult%10);
 
-        if (fsb == 0) {
-                printk (KERN_INFO PFX "Invalid (reserved) FSB!\n");
-                return -EINVAL;
-        }
-
         highest_speed = calc_speed(maxmult);
         lowest_speed = calc_speed(minmult);
         dprintk ("FSB:%dMHz  Lowest speed: %s   Highest speed:%s\n", fsb,
@@ -634,21 +615,23 @@ static int __init longhaul_cpu_init(struct cpufreq_policy *policy)
                 break;
 
         case 9:
-                cpu_model = CPU_NEHEMIAH;
                 longhaul_version = TYPE_POWERSAVER;
                 numscales=32;
                 switch (c->x86_mask) {
                 case 0 ... 1:
+                        cpu_model = CPU_NEHEMIAH;
                         cpuname = "C3 'Nehemiah A' [C5N]";
                         memcpy (clock_ratio, nehemiah_a_clock_ratio, sizeof(nehemiah_a_clock_ratio));
                         memcpy (eblcr_table, nehemiah_a_eblcr, sizeof(nehemiah_a_eblcr));
                         break;
                 case 2 ... 4:
+                        cpu_model = CPU_NEHEMIAH;
                         cpuname = "C3 'Nehemiah B' [C5N]";
                         memcpy (clock_ratio, nehemiah_b_clock_ratio, sizeof(nehemiah_b_clock_ratio));
                         memcpy (eblcr_table, nehemiah_b_eblcr, sizeof(nehemiah_b_eblcr));
                         break;
                 case 5 ... 15:
+                        cpu_model = CPU_NEHEMIAH_C;
                         cpuname = "C3 'Nehemiah C' [C5N]";
                         memcpy (clock_ratio, nehemiah_c_clock_ratio, sizeof(nehemiah_c_clock_ratio));
                         memcpy (eblcr_table, nehemiah_c_eblcr, sizeof(nehemiah_c_eblcr));