[CPUFREQ] architectural pstate driver for powernow-k8

This patch should apply cleanly to the 2.6.23-git7 kernel.  It changes the
powernow-k8 driver code that deals with 3rd generation Opteron, Phenom,
and later processors to match the architectural pstate driver described
in the AMD64 Architecture Programmer's Manual Volume 2 Chapter 18.  The
initial implementation of the hardware pstate driver for PowerNow!
used some processor-version specific features, and would not be
maintainable in the long term as the processor features changed.
This architectural driver should work on all future AMD processors.
 
Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>

2 files changed, 29 insertions, 81 deletions

diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index b273b69cfddf..f105ffd09960 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -46,7 +46,7 @@
 
 #define PFX "powernow-k8: "
 #define BFX PFX "BIOS error: "
-#define VERSION "version 2.00.00"
+#define VERSION "version 2.20.00"
 #include "powernow-k8.h"
 
 /* serialize freq changes  */
@@ -73,33 +73,11 @@ static u32 find_khz_freq_from_fid(u32 fid)
         return 1000 * find_freq_from_fid(fid);
 }
 
-/* Return a frequency in MHz, given an input fid and did */
-static u32 find_freq_from_fiddid(u32 fid, u32 did)
+static u32 find_khz_freq_from_pstate(struct cpufreq_frequency_table *data, u32 pstate)
 {
-        if (current_cpu_data.x86 == 0x10)
-                return 100 * (fid + 0x10) >> did;
-        else
-                return 100 * (fid + 0x8) >> did;
-}
-
-static u32 find_khz_freq_from_fiddid(u32 fid, u32 did)
-{
-        return 1000 * find_freq_from_fiddid(fid, did);
-}
-
-static u32 find_fid_from_pstate(u32 pstate)
-{
-        u32 hi, lo;
-        rdmsr(MSR_PSTATE_DEF_BASE + pstate, lo, hi);
-        return lo & HW_PSTATE_FID_MASK;
+        return data[pstate].frequency;
 }
 
-static u32 find_did_from_pstate(u32 pstate)
-{
-        u32 hi, lo;
-        rdmsr(MSR_PSTATE_DEF_BASE + pstate, lo, hi);
-        return (lo & HW_PSTATE_DID_MASK) >> HW_PSTATE_DID_SHIFT;
-}
 
 /* Return the vco fid for an input fid
  *
@@ -142,9 +120,7 @@ static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
         if (cpu_family == CPU_HW_PSTATE) {
                 rdmsr(MSR_PSTATE_STATUS, lo, hi);
                 i = lo & HW_PSTATE_MASK;
-                rdmsr(MSR_PSTATE_DEF_BASE + i, lo, hi);
-                data->currfid = lo & HW_PSTATE_FID_MASK;
-                data->currdid = (lo & HW_PSTATE_DID_MASK) >> HW_PSTATE_DID_SHIFT;
+                data->currpstate = i;
                 return 0;
         }
         do {
@@ -295,7 +271,7 @@ static int decrease_vid_code_by_step(struct powernow_k8_data *data, u32 reqvid,
 static int transition_pstate(struct powernow_k8_data *data, u32 pstate)
 {
         wrmsr(MSR_PSTATE_CTRL, pstate, 0);
-        data->currfid = find_fid_from_pstate(pstate);
+        data->currpstate = pstate;
         return 0;
 }
 
@@ -845,17 +821,20 @@ err_out:
 static int fill_powernow_table_pstate(struct powernow_k8_data *data, struct cpufreq_frequency_table *powernow_table)
 {
         int i;
+        u32 hi = 0, lo = 0;
+        rdmsr(MSR_PSTATE_CUR_LIMIT, hi, lo);
+        data->max_hw_pstate = (hi & HW_PSTATE_MAX_MASK) >> HW_PSTATE_MAX_SHIFT;
 
         for (i = 0; i < data->acpi_data.state_count; i++) {
                 u32 index;
                 u32 hi = 0, lo = 0;
-                u32 fid;
-                u32 did;
 
                 index = data->acpi_data.states[i].control & HW_PSTATE_MASK;
-                if (index > MAX_HW_PSTATE) {
+                if (index > data->max_hw_pstate) {
                         printk(KERN_ERR PFX "invalid pstate %d - bad value %d.\n", i, index);
                         printk(KERN_ERR PFX "Please report to BIOS manufacturer\n");
+                        powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID;
+                        continue;
                 }
                 rdmsr(MSR_PSTATE_DEF_BASE + index, lo, hi);
                 if (!(hi & HW_PSTATE_VALID_MASK)) {
@@ -864,22 +843,9 @@ static int fill_powernow_table_pstate(struct powernow_k8_data *data, struct cpuf
                         continue;
                 }
 
-                fid = lo & HW_PSTATE_FID_MASK;
-                did = (lo & HW_PSTATE_DID_MASK) >> HW_PSTATE_DID_SHIFT;
+                powernow_table[i].index = index;
 
-                dprintk("   %d : fid 0x%x, did 0x%x\n", index, fid, did);
-
-                powernow_table[i].index = index | (fid << HW_FID_INDEX_SHIFT) | (did << HW_DID_INDEX_SHIFT);
-
-                powernow_table[i].frequency = find_khz_freq_from_fiddid(fid, did);
-
-                if (powernow_table[i].frequency != (data->acpi_data.states[i].core_frequency * 1000)) {
-                        printk(KERN_INFO PFX "invalid freq entries %u kHz vs. %u kHz\n",
-                                powernow_table[i].frequency,
-                                (unsigned int) (data->acpi_data.states[i].core_frequency * 1000));
-                        powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID;
-                        continue;
-                }
+                powernow_table[i].frequency = data->acpi_data.states[i].core_frequency * 1000;
         }
         return 0;
 }
@@ -1020,22 +986,18 @@ static int transition_frequency_fidvid(struct powernow_k8_data *data, unsigned i
 /* Take a frequency, and issue the hardware pstate transition command */
 static int transition_frequency_pstate(struct powernow_k8_data *data, unsigned int index)
 {
-        u32 fid = 0;
-        u32 did = 0;
         u32 pstate = 0;
         int res, i;
         struct cpufreq_freqs freqs;
 
         dprintk("cpu %d transition to index %u\n", smp_processor_id(), index);
 
-        /* get fid did for hardware pstate transition */
+        /* get MSR index for hardware pstate transition */
         pstate = index & HW_PSTATE_MASK;
-        if (pstate > MAX_HW_PSTATE)
+        if (pstate > data->max_hw_pstate)
                 return 0;
-        fid = (index & HW_FID_INDEX_MASK) >> HW_FID_INDEX_SHIFT;
-        did = (index & HW_DID_INDEX_MASK) >> HW_DID_INDEX_SHIFT;
-        freqs.old = find_khz_freq_from_fiddid(data->currfid, data->currdid);
-        freqs.new = find_khz_freq_from_fiddid(fid, did);
+        freqs.old = find_khz_freq_from_pstate(data->powernow_table, data->currpstate);
+        freqs.new = find_khz_freq_from_pstate(data->powernow_table, pstate);
 
         for_each_cpu_mask(i, *(data->available_cores)) {
                 freqs.cpu = i;
@@ -1043,9 +1005,7 @@ static int transition_frequency_pstate(struct powernow_k8_data *data, unsigned i
         }
 
         res = transition_pstate(data, pstate);
-        data->currfid = find_fid_from_pstate(pstate);
-        data->currdid = find_did_from_pstate(pstate);
-        freqs.new = find_khz_freq_from_fiddid(data->currfid, data->currdid);
+        freqs.new = find_khz_freq_from_pstate(data->powernow_table, pstate);
 
         for_each_cpu_mask(i, *(data->available_cores)) {
                 freqs.cpu = i;
@@ -1090,10 +1050,7 @@ static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsi
         if (query_current_values_with_pending_wait(data))
                 goto err_out;
 
-        if (cpu_family == CPU_HW_PSTATE)
-                dprintk("targ: curr fid 0x%x, did 0x%x\n",
-                        data->currfid, data->currdid);
-        else {
+        if (cpu_family != CPU_HW_PSTATE) {
                 dprintk("targ: curr fid 0x%x, vid 0x%x\n",
                 data->currfid, data->currvid);
 
@@ -1124,7 +1081,7 @@ static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsi
         mutex_unlock(&fidvid_mutex);
 
         if (cpu_family == CPU_HW_PSTATE)
-                pol->cur = find_khz_freq_from_fiddid(data->currfid, data->currdid);
+                pol->cur = find_khz_freq_from_pstate(data->powernow_table, newstate);
         else
                 pol->cur = find_khz_freq_from_fid(data->currfid);
         ret = 0;
@@ -1223,7 +1180,7 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
             + (3 * (1 << data->irt) * 10)) * 1000;
 
         if (cpu_family == CPU_HW_PSTATE)
-                pol->cur = find_khz_freq_from_fiddid(data->currfid, data->currdid);
+                pol->cur = find_khz_freq_from_pstate(data->powernow_table, data->currpstate);
         else
                 pol->cur = find_khz_freq_from_fid(data->currfid);
         dprintk("policy current frequency %d kHz\n", pol->cur);
@@ -1240,8 +1197,7 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
         cpufreq_frequency_table_get_attr(data->powernow_table, pol->cpu);
 
         if (cpu_family == CPU_HW_PSTATE)
-                dprintk("cpu_init done, current fid 0x%x, did 0x%x\n",
-                        data->currfid, data->currdid);
+                dprintk("cpu_init done, current pstate 0x%x\n", data->currpstate);
         else
                 dprintk("cpu_init done, current fid 0x%x, vid 0x%x\n",
                         data->currfid, data->currvid);
@@ -1297,7 +1253,7 @@ static unsigned int powernowk8_get (unsigned int cpu)
                 goto out;
 
         if (cpu_family == CPU_HW_PSTATE)
-                khz = find_khz_freq_from_fiddid(data->currfid, data->currdid);
+                khz = find_khz_freq_from_pstate(data->powernow_table, data->currpstate);
         else
                 khz = 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 b06c812208ca..8ae88f181286 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
@@ -10,6 +10,7 @@ struct powernow_k8_data {
 
         u32 numps;  /* number of p-states */
         u32 batps;  /* number of p-states supported on battery */
+        u32 max_hw_pstate; /* maximum legal hardware pstate */
 
         /* these values are constant when the PSB is used to determine
          * vid/fid pairings, but are modified during the ->target() call
@@ -21,8 +22,8 @@ struct powernow_k8_data {
         u32 plllock; /* pll lock time, units 1 us */
         u32 exttype; /* extended interface = 1 */
 
-        /* keep track of the current fid / vid or did */
-        u32 currvid, currfid, currdid;
+        /* keep track of the current fid / vid or pstate */
+        u32 currvid, currfid, currpstate;
 
         /* the powernow_table includes all frequency and vid/fid pairings:
          * fid are the lower 8 bits of the index, vid are the upper 8 bits.
@@ -87,23 +88,14 @@ struct powernow_k8_data {
 
 /* Hardware Pstate _PSS and MSR definitions */
 #define USE_HW_PSTATE           0x00000080
-#define HW_PSTATE_FID_MASK      0x0000003f
-#define HW_PSTATE_DID_MASK      0x000001c0
-#define HW_PSTATE_DID_SHIFT     6
 #define HW_PSTATE_MASK          0x00000007
 #define HW_PSTATE_VALID_MASK    0x80000000
-#define HW_FID_INDEX_SHIFT      8
-#define HW_FID_INDEX_MASK       0x0000ff00
-#define HW_DID_INDEX_SHIFT      16
-#define HW_DID_INDEX_MASK       0x00ff0000
-#define HW_WATTS_MASK           0xff
-#define HW_PWR_DVR_MASK         0x300
-#define HW_PWR_DVR_SHIFT        8
-#define HW_PWR_MAX_MULT         3
-#define MAX_HW_PSTATE           8       /* hw pstate supports up to 8 */
+#define HW_PSTATE_MAX_MASK      0x000000f0
+#define HW_PSTATE_MAX_SHIFT     4
 #define MSR_PSTATE_DEF_BASE     0xc0010064 /* base of Pstate MSRs */
 #define MSR_PSTATE_STATUS       0xc0010063 /* Pstate Status MSR */
 #define MSR_PSTATE_CTRL         0xc0010062 /* Pstate control MSR */
+#define MSR_PSTATE_CUR_LIMIT    0xc0010061 /* pstate current limit MSR */
 
 /* define the two driver architectures */
 #define CPU_OPTERON 0