[PATCH v4 04/15] xen/cpufreq: refactor cmdline "cpufreq=xxx"

[Penny Zheng <Penny.Zheng@xxxxxxx>]

A helper function handle_cpufreq_cmdline() is introduced to tidy different
handling pathes.
We also add a new helper cpufreq_opts_contain() to ignore and warn user
redundant setting, like "cpufreq=hwp;hwp;xen"

Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
---
v2 -> v3:
- new commit
---
v3 -> v4:
- add one single helper to do the tidy work
- ignore and warn user redundant setting
---
 xen/drivers/cpufreq/cpufreq.c | 53 +++++++++++++++++++++++++++++------
 1 file changed, 45 insertions(+), 8 deletions(-)

diff --git a/xen/drivers/cpufreq/cpufreq.c b/xen/drivers/cpufreq/cpufreq.c
index e01acc0c2d..79c6444116 100644
--- a/xen/drivers/cpufreq/cpufreq.c
+++ b/xen/drivers/cpufreq/cpufreq.c
@@ -71,6 +71,49 @@ unsigned int __initdata cpufreq_xen_cnt = 1;
 
 static int __init cpufreq_cmdline_parse(const char *s, const char *e);
 
+static bool __init cpufreq_opts_contain(enum cpufreq_xen_opt option)
+{
+    unsigned int count = cpufreq_xen_cnt;
+
+    while ( count )
+    {
+        if ( cpufreq_xen_opts[--count] == option )
+            return true;
+    }
+
+    return false;
+}
+
+static int __init handle_cpufreq_cmdline(enum cpufreq_xen_opt option)
+{
+    int ret = 0;
+
+    if ( cpufreq_opts_contain(option) )
+    {
+        const char *cpufreq_opts_str[] = { "CPUFREQ_xen", "CPUFREQ_hwp" };
+
+        printk(XENLOG_WARNING
+               "Duplicate cpufreq driver option: %s",
+               cpufreq_opts_str[option - 1]);
+        return 0;
+    }
+
+    cpufreq_controller = FREQCTL_xen;
+    cpufreq_xen_opts[cpufreq_xen_cnt++] = option;
+    switch ( option )
+    {
+    case CPUFREQ_hwp:
+    case CPUFREQ_xen:
+        xen_processor_pmbits |= XEN_PROCESSOR_PM_PX;
+        break;
+    default:
+        ret = -EINVAL;
+        break;
+    }
+
+    return ret;
+}
+
 static int __init cf_check setup_cpufreq_option(const char *str)
 {
     const char *arg = strpbrk(str, ",:;");
@@ -114,20 +157,14 @@ static int __init cf_check setup_cpufreq_option(const 
char *str)
 
         if ( choice > 0 || !cmdline_strcmp(str, "xen") )
         {
-            xen_processor_pmbits |= XEN_PROCESSOR_PM_PX;
-            cpufreq_controller = FREQCTL_xen;
-            cpufreq_xen_opts[cpufreq_xen_cnt++] = CPUFREQ_xen;
-            ret = 0;
+            ret = handle_cpufreq_cmdline(CPUFREQ_xen);
             if ( arg[0] && arg[1] )
                 ret = cpufreq_cmdline_parse(arg + 1, end);
         }
         else if ( IS_ENABLED(CONFIG_INTEL) && choice < 0 &&
                   !cmdline_strcmp(str, "hwp") )
         {
-            xen_processor_pmbits |= XEN_PROCESSOR_PM_PX;
-            cpufreq_controller = FREQCTL_xen;
-            cpufreq_xen_opts[cpufreq_xen_cnt++] = CPUFREQ_hwp;
-            ret = 0;
+            ret = handle_cpufreq_cmdline(CPUFREQ_hwp);
             if ( arg[0] && arg[1] )
                 ret = hwp_cmdline_parse(arg + 1, end);
         }
-- 
2.34.1