[PATCH v2 02/11] xen/x86: introduce new sub-hypercall to propagate CPPC data

[Penny Zheng <Penny.Zheng@xxxxxxx>]

In order to provide backward compatibility with existing governors
that represent performance as frequencies, like ondemand, the _CPC
table can optionally provide processor frequency range values, Lowest
frequency and Norminal frequency, to let OS use Lowest Frequency/
Performance and Nominal Frequency/Performance as anchor points to
create linear mapping of CPPC abstract performance to CPU frequency.

As Xen is uncapable of parsing the ACPI dynamic table, this commit
introduces a new sub-hypercall to propagate required CPPC data from
dom0 kernel.

Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
---
v1 -> v2:
- Remove unnecessary figure braces
- Pointer-to-const for print_CPPC and set_cppc_pminfo
- Structure allocation shall use xvzalloc()
- Unnecessary memcpy(), and change it to a (type safe) structure assignment
- Add comment for struct xen_processor_cppc, and keep the chosen fields
in the order _CPC has them
- Obey to alphabetic sorting, and prefix compat structures with ? instead
of !
---
 xen/arch/x86/platform_hypercall.c         |  4 ++
 xen/arch/x86/x86_64/cpufreq.c             |  2 +
 xen/drivers/cpufreq/cpufreq.c             | 48 +++++++++++++++++++++++
 xen/include/acpi/cpufreq/processor_perf.h |  1 +
 xen/include/public/platform.h             | 16 ++++++++
 xen/include/xen/pmstat.h                  |  1 +
 xen/include/xlat.lst                      |  1 +
 7 files changed, 73 insertions(+)

diff --git a/xen/arch/x86/platform_hypercall.c 
b/xen/arch/x86/platform_hypercall.c
index 67f851237d..735c71b0e7 100644
--- a/xen/arch/x86/platform_hypercall.c
+++ b/xen/arch/x86/platform_hypercall.c
@@ -572,6 +572,10 @@ ret_t do_platform_op(
             break;
         }
 
+        case XEN_PM_CPPC:
+            ret = set_cppc_pminfo(op->u.set_pminfo.id, 
&op->u.set_pminfo.u.cppc_data);
+            break;
+
         default:
             ret = -EINVAL;
             break;
diff --git a/xen/arch/x86/x86_64/cpufreq.c b/xen/arch/x86/x86_64/cpufreq.c
index e4f3d5b436..aa72037401 100644
--- a/xen/arch/x86/x86_64/cpufreq.c
+++ b/xen/arch/x86/x86_64/cpufreq.c
@@ -26,6 +26,8 @@
 #include <xen/pmstat.h>
 #include <compat/platform.h>
 
+CHECK_processor_cppc;
+
 CHECK_processor_px;
 
 DEFINE_XEN_GUEST_HANDLE(compat_processor_px_t);
diff --git a/xen/drivers/cpufreq/cpufreq.c b/xen/drivers/cpufreq/cpufreq.c
index 4a103c6de9..f5e8bfa09e 100644
--- a/xen/drivers/cpufreq/cpufreq.c
+++ b/xen/drivers/cpufreq/cpufreq.c
@@ -40,6 +40,7 @@
 #include <xen/domain.h>
 #include <xen/cpu.h>
 #include <xen/pmstat.h>
+#include <xen/xvmalloc.h>
 #include <asm/io.h>
 #include <asm/processor.h>
 
@@ -458,6 +459,53 @@ static void print_PPC(unsigned int platform_limit)
     printk("\t_PPC: %d\n", platform_limit);
 }
 
+static void print_CPPC(const struct xen_processor_cppc *cppc_data)
+{
+    printk("\t_CPC: highest_perf=%u, lowest_perf=%u, "
+           "nominal_perf=%u, lowest_nonlinear_perf=%u, "
+           "nominal_freq=%uMhz, lowest_freq=%uMhz\n",
+           cppc_data->highest_perf, cppc_data->lowest_perf,
+           cppc_data->nominal_perf, cppc_data->lowest_nonlinear_perf,
+           cppc_data->nominal_freq, cppc_data->lowest_freq);
+}
+
+int set_cppc_pminfo(uint32_t acpi_id, const struct xen_processor_cppc 
*cppc_data)
+{
+    int ret = 0, cpuid;
+    struct processor_pminfo *pm_info;
+
+    cpuid = get_cpu_id(acpi_id);
+    if ( cpuid < 0 || !cppc_data )
+    {
+        ret = -EINVAL;
+        goto out;
+    }
+    if ( cpufreq_verbose )
+        printk("Set CPU acpi_id(%d) cpuid(%d) CPPC State info:\n",
+               acpi_id, cpuid);
+
+    pm_info = processor_pminfo[cpuid];
+    if ( !pm_info )
+    {
+        pm_info = xvzalloc(struct processor_pminfo);
+        if ( !pm_info )
+        {
+            ret = -ENOMEM;
+            goto out;
+        }
+        processor_pminfo[cpuid] = pm_info;
+    }
+    pm_info->acpi_id = acpi_id;
+    pm_info->id = cpuid;
+    pm_info->cppc_data = *cppc_data;
+
+    if ( cpufreq_verbose )
+        print_CPPC(&pm_info->cppc_data);
+
+ out:
+    return ret;
+}
+
 int set_px_pminfo(uint32_t acpi_id, struct xen_processor_performance *perf)
 {
     int ret = 0, cpu;
diff --git a/xen/include/acpi/cpufreq/processor_perf.h 
b/xen/include/acpi/cpufreq/processor_perf.h
index 301104e16f..cfa0fed647 100644
--- a/xen/include/acpi/cpufreq/processor_perf.h
+++ b/xen/include/acpi/cpufreq/processor_perf.h
@@ -37,6 +37,7 @@ struct processor_pminfo {
     uint32_t acpi_id;
     uint32_t id;
     struct processor_performance    perf;
+    struct xen_processor_cppc cppc_data;
 };
 
 extern struct processor_pminfo *processor_pminfo[NR_CPUS];
diff --git a/xen/include/public/platform.h b/xen/include/public/platform.h
index 2725b8d104..b8daa8fc42 100644
--- a/xen/include/public/platform.h
+++ b/xen/include/public/platform.h
@@ -363,6 +363,7 @@ DEFINE_XEN_GUEST_HANDLE(xenpf_getidletime_t);
 #define XEN_PM_PX   1
 #define XEN_PM_TX   2
 #define XEN_PM_PDC  3
+#define XEN_PM_CPPC 4
 
 /* Px sub info type */
 #define XEN_PX_PCT   1
@@ -432,6 +433,20 @@ struct xen_processor_px {
 typedef struct xen_processor_px xen_processor_px_t;
 DEFINE_XEN_GUEST_HANDLE(xen_processor_px_t);
 
+/*
+ * Subset _CPC fields useful for CPPC-compatible cpufreq
+ * driver's initialization
+ */
+struct xen_processor_cppc {
+    uint32_t highest_perf;
+    uint32_t nominal_perf;
+    uint32_t lowest_nonlinear_perf;
+    uint32_t lowest_perf;
+    uint32_t lowest_freq;
+    uint32_t nominal_freq;
+};
+typedef struct xen_processor_cppc xen_processor_cppc_t;
+
 struct xen_psd_package {
     uint64_t num_entries;
     uint64_t revision;
@@ -465,6 +480,7 @@ struct xenpf_set_processor_pminfo {
         struct xen_processor_power          power;/* Cx: _CST/_CSD */
         struct xen_processor_performance    perf; /* Px: _PPC/_PCT/_PSS/_PSD */
         XEN_GUEST_HANDLE(uint32)            pdc;  /* _PDC */
+        xen_processor_cppc_t                cppc_data; /*_CPC */
     } u;
 };
 typedef struct xenpf_set_processor_pminfo xenpf_set_processor_pminfo_t;
diff --git a/xen/include/xen/pmstat.h b/xen/include/xen/pmstat.h
index 8350403e95..d2fe74ef0b 100644
--- a/xen/include/xen/pmstat.h
+++ b/xen/include/xen/pmstat.h
@@ -5,6 +5,7 @@
 #include <public/platform.h> /* for struct xen_processor_power */
 #include <public/sysctl.h>   /* for struct pm_cx_stat */
 
+int set_cppc_pminfo(uint32_t cpu, const struct xen_processor_cppc *cppc_data);
 int set_px_pminfo(uint32_t acpi_id, struct xen_processor_performance *perf);
 long set_cx_pminfo(uint32_t acpi_id, struct xen_processor_power *power);
 
diff --git a/xen/include/xlat.lst b/xen/include/xlat.lst
index 3c7b6c6830..20201c1667 100644
--- a/xen/include/xlat.lst
+++ b/xen/include/xlat.lst
@@ -162,6 +162,7 @@
 
 !      pct_register                    platform.h
 !      power_register                  platform.h
+?      processor_cppc                  platform.h
 ?      processor_csd                   platform.h
 !      processor_cx                    platform.h
 !      processor_flags                 platform.h
-- 
2.34.1