[CPUFREQ] Powernow-k8: support family 0xf with 2 low p-states

Provide support for family 0xf processors with 2 P-states
below the elevator voltage.  Remove the checks that prevent
this configuration from being supported and increase the
transition voltage to prevent errors during the transition.

Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>

2 files changed, 13 insertions, 20 deletions

diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index 81cbe64ed6b4..ae068f59603f 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -299,7 +299,7 @@ static int transition_pstate(struct powernow_k8_data *data, u32 pstate)
 static int transition_fid_vid(struct powernow_k8_data *data,
                 u32 reqfid, u32 reqvid)
 {
-        if (core_voltage_pre_transition(data, reqvid))
+        if (core_voltage_pre_transition(data, reqvid, reqfid))
                 return 1;
 
         if (core_frequency_transition(data, reqfid))
@@ -327,17 +327,20 @@ static int transition_fid_vid(struct powernow_k8_data *data,
 
 /* Phase 1 - core voltage transition ... setup voltage */
 static int core_voltage_pre_transition(struct powernow_k8_data *data,
-                u32 reqvid)
+                u32 reqvid, u32 reqfid)
 {
         u32 rvosteps = data->rvo;
         u32 savefid = data->currfid;
-        u32 maxvid, lo;
+        u32 maxvid, lo, rvomult = 1;
 
         dprintk("ph1 (cpu%d): start, currfid 0x%x, currvid 0x%x, "
                 "reqvid 0x%x, rvo 0x%x\n",
                 smp_processor_id(),
                 data->currfid, data->currvid, reqvid, data->rvo);
 
+        if ((savefid < LO_FID_TABLE_TOP) && (reqfid < LO_FID_TABLE_TOP))
+                rvomult = 2;
+        rvosteps *= rvomult;
         rdmsr(MSR_FIDVID_STATUS, lo, maxvid);
         maxvid = 0x1f & (maxvid >> 16);
         dprintk("ph1 maxvid=0x%x\n", maxvid);
@@ -351,7 +354,8 @@ static int core_voltage_pre_transition(struct powernow_k8_data *data,
                         return 1;
         }
 
-        while ((rvosteps > 0) && ((data->rvo + data->currvid) > reqvid)) {
+        while ((rvosteps > 0) &&
+                        ((rvomult * data->rvo + data->currvid) > reqvid)) {
                 if (data->currvid == maxvid) {
                         rvosteps = 0;
                 } else {
@@ -384,13 +388,6 @@ static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid)
         u32 vcoreqfid, vcocurrfid, vcofiddiff;
         u32 fid_interval, savevid = data->currvid;
 
-        if ((reqfid < HI_FID_TABLE_BOTTOM) &&
-            (data->currfid < HI_FID_TABLE_BOTTOM)) {
-                printk(KERN_ERR PFX "ph2: illegal lo-lo transition "
-                                "0x%x 0x%x\n", reqfid, data->currfid);
-                return 1;
-        }
-
         if (data->currfid == reqfid) {
                 printk(KERN_ERR PFX "ph2 null fid transition 0x%x\n",
                                 data->currfid);
@@ -407,6 +404,9 @@ static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid)
         vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
             : vcoreqfid - vcocurrfid;
 
+        if ((reqfid <= LO_FID_TABLE_TOP) && (data->currfid <= LO_FID_TABLE_TOP))
+                vcofiddiff = 0;
+
         while (vcofiddiff > 2) {
                 (data->currfid & 1) ? (fid_interval = 1) : (fid_interval = 2);
 
@@ -1081,14 +1081,6 @@ static int transition_frequency_fidvid(struct powernow_k8_data *data,
                 return 0;
         }
 
-        if ((fid < HI_FID_TABLE_BOTTOM) &&
-            (data->currfid < HI_FID_TABLE_BOTTOM)) {
-                printk(KERN_ERR PFX
-                       "ignoring illegal change in lo freq table-%x to 0x%x\n",
-                       data->currfid, fid);
-                return 1;
-        }
-
         dprintk("cpu %d, changing to fid 0x%x, vid 0x%x\n",
                 smp_processor_id(), fid, vid);
         freqs.old = find_khz_freq_from_fid(data->currfid);
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
index c9c1190b5e1f..02ce824073cb 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
@@ -215,7 +215,8 @@ struct pst_s {
 
 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "powernow-k8", msg)
 
-static int core_voltage_pre_transition(struct powernow_k8_data *data, u32 reqvid);
+static int core_voltage_pre_transition(struct powernow_k8_data *data,
+        u32 reqvid, u32 regfid);
 static int core_voltage_post_transition(struct powernow_k8_data *data, u32 reqvid);
 static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid);