[PATCH v3 07/15] xen/cpufreq: fix core frequency calculation for AMD Family 1Ah CPUs

[Penny Zheng <Penny.Zheng@xxxxxxx>]

This commit fixes core frequency calculation for AMD Family 1Ah CPUs, due to
a change in the PStateDef MSR layout in AMD Family 1Ah+.
In AMD Family 1Ah+, Core current operating frequency in MHz is calculated as
follows:
CoreCOF = Core::X86::Msr::PStateDef[CpuFid[11:0]] * 5MHz

Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
---
v2 -> v3:
- new commit
---
 xen/arch/x86/cpu/amd.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c
index 597b0f073d..7fb1d76798 100644
--- a/xen/arch/x86/cpu/amd.c
+++ b/xen/arch/x86/cpu/amd.c
@@ -572,12 +572,24 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
                                                           : c->cpu_core_id);
 }
 
+static uint64_t amd_parse_freq(const struct cpuinfo_x86 *c, uint64_t value)
+{
+       ASSERT(c->x86 <= 0x1A);
+
+       if (c->x86 < 0x17)
+               return (((value & 0x3f) + 0x10) * 100) >> ((value >> 6) & 7);
+       else if (c->x86 <= 0x19)
+               return ((value & 0xff) * 25 * 8) / ((value >> 8) & 0x3f);
+       else
+               return (value & 0xfff) * 5;
+}
+
 void amd_log_freq(const struct cpuinfo_x86 *c)
 {
        unsigned int idx = 0, h;
        uint64_t hi, lo, val;
 
-       if (c->x86 < 0x10 || c->x86 > 0x19 ||
+       if (c->x86 < 0x10 || c->x86 > 0x1A ||
            (c != &boot_cpu_data &&
             (!opt_cpu_info || (c->apicid & (c->x86_num_siblings - 1)))))
                return;
@@ -658,19 +670,20 @@ void amd_log_freq(const struct cpuinfo_x86 *c)
        if (!(lo >> 63))
                return;
 
-#define FREQ(v) (c->x86 < 0x17 ? ((((v) & 0x3f) + 0x10) * 100) >> (((v) >> 6) 
& 7) \
-                                    : (((v) & 0xff) * 25 * 8) / (((v) >> 8) & 
0x3f))
        if (idx && idx < h &&
            !rdmsr_safe(0xC0010064 + idx, val) && (val >> 63) &&
            !rdmsr_safe(0xC0010064, hi) && (hi >> 63))
                printk("CPU%u: %lu (%lu ... %lu) MHz\n",
-                      smp_processor_id(), FREQ(val), FREQ(lo), FREQ(hi));
+                      smp_processor_id(),
+                      amd_parse_freq(c, val),
+                      amd_parse_freq(c, lo), amd_parse_freq(c, hi));
        else if (h && !rdmsr_safe(0xC0010064, hi) && (hi >> 63))
                printk("CPU%u: %lu ... %lu MHz\n",
-                      smp_processor_id(), FREQ(lo), FREQ(hi));
+                      smp_processor_id(),
+                      amd_parse_freq(c, lo), amd_parse_freq(c, hi));
        else
-               printk("CPU%u: %lu MHz\n", smp_processor_id(), FREQ(lo));
-#undef FREQ
+               printk("CPU%u: %lu MHz\n", smp_processor_id(),
+                      amd_parse_freq(c, lo));
 }
 
 void cf_check early_init_amd(struct cpuinfo_x86 *c)
-- 
2.34.1