[PATCH] cpufreq: acpi: Allow new dynamics attributes to be added to acpi_cpufreq_attr

[Viresh Kumar]

acpi_cpufreq_attr contains at least one dynamically populated (removed)
attribute today, cpb. But the code isn't friendly enough for new
attributes to be populated in a similar way.

Make some changes to allow new attributes to be easily added to the
struct.

Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
---
Srinivas,

This should make it easy for you to add another dynamic entry into the
acpi_cpufreq_attr structure.

 drivers/cpufreq/acpi-cpufreq.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index 59a7b380fbe2..c37617ddcc9e 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -866,7 +866,7 @@ static struct freq_attr *acpi_cpufreq_attr[] = {
        &cpufreq_freq_attr_scaling_available_freqs,
        &freqdomain_cpus,
 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
-       &cpb,
+       NULL,   /* Extra space for cpb if required */
 #endif
        NULL,
 };
@@ -917,6 +917,7 @@ static void acpi_cpufreq_boost_exit(void)
 
 static int __init acpi_cpufreq_init(void)
 {
+       struct freq_attr **attr;
        int ret;
 
        if (acpi_disabled)
@@ -932,6 +933,10 @@ static int __init acpi_cpufreq_init(void)
        if (ret)
                return ret;
 
+       /* Find first empty entry */
+       for (attr = acpi_cpufreq_attr; *attr; attr++)
+               ;
+
 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
        /* this is a sysfs file with a strange name and an even stranger
         * semantic - per CPU instantiation, but system global effect.
@@ -939,17 +944,11 @@ static int __init acpi_cpufreq_init(void)
         * only if configured. This is considered legacy code, which
         * will probably be removed at some point in the future.
         */
-       if (!check_amd_hwpstate_cpu(0)) {
-               struct freq_attr **attr;
-
+       if (check_amd_hwpstate_cpu(0))
+               *attr++ = &cpb;
+       else
                pr_debug("CPB unsupported, do not expose it\n");
 
-               for (attr = acpi_cpufreq_attr; *attr; attr++)
-                       if (*attr == &cpb) {
-                               *attr = NULL;
-                               break;
-                       }
-       }
 #endif
        acpi_cpufreq_boost_init();
 
-- 
2.7.1.410.g6faf27b