[ACPI] update C-state limiting patch

Now "max_cstate=" instead of "acpi_cstate_limit="
Delete redundant static cstate flags .c2 and .c3

http://bugme.osdl.org/show_bug.cgi?id=3549

   For static processor driver, boot cmdline:
   processor.max_cstate=2

   For processor module, /etc/modprobe.conf:
   options processor max_cstate=2
   or
   # modprobe processor max_cstate=2

   From kernel or kernel module:
   #include <linux/acpi.h>
   acpi_set_cstate_limit(2);

Suggested-by: Pavel Machek
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index c311746b8956c1fdc49834ac3779130f6ccbc476..4013d55387c82811ab5f3a9102acff7e95295eb2 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -960,10 +960,9 @@ running once the system is up.
                        (param: profile step/bucket size as a power of 2 for
                                statistical time based profiling)
 
-       processor.c2=   [HW, ACPI]
-       processor.c3=   [HW, ACPI]
-                       0 - disable C2 or C3 idle power saving state.
-                       1 - enable C2 or C3 (default unless DMI blacklist entry)
+       processor.max_cstate=   [HW, ACPI]
+                       Limit processor to maximum C-state
+                       max_cstate=9 overrides any DMI blacklist limit.
 
        prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
                        before loading.

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 50ae36382b9c500c82cbb7c04fa43e435625e818..5d8afd7ab2cae60ff3db189c0d80415361c09f9c 100644 (file)
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -1152,10 +1152,10 @@ acpi_wake_gpes_always_on_setup(char *str)
 __setup("acpi_wake_gpes_always_on", acpi_wake_gpes_always_on_setup);
 
 /*
- * acpi_cstate_limit is defined in the base kernel so modules can
+ * max_cstate is defined in the base kernel so modules can
  * change it w/o depending on the state of the processor module.
  */
-unsigned int acpi_cstate_limit = ACPI_C_STATES_MAX;
+unsigned int max_cstate = ACPI_C_STATES_MAX;
 
 
-EXPORT_SYMBOL(acpi_cstate_limit);
+EXPORT_SYMBOL(max_cstate);

diff --git a/drivers/acpi/processor.c b/drivers/acpi/processor.c
index c7eb59396a92fc3a8654f5f5a61d3c0cb3a6a173..b7d37b5156186482b00a73acc0d71d6b2709c632 100644 (file)
--- a/drivers/acpi/processor.c
+++ b/drivers/acpi/processor.c
@@ -101,8 +101,6 @@ static struct acpi_driver acpi_processor_driver = {
                        },
 };
 
-static int c2 = -1;
-static int c3 = -1;
 
 struct acpi_processor_errata {
        u8                      smp;
@@ -144,8 +142,6 @@ static struct file_operations acpi_processor_limit_fops = {
 
 static struct acpi_processor   *processors[NR_CPUS];
 static struct acpi_processor_errata errata;
-module_param_named(c2, c2, bool, 0);
-module_param_named(c3, c3, bool, 0);
 static void (*pm_idle_save)(void);
 
 
@@ -338,8 +334,8 @@ acpi_processor_idle (void)
 {
        struct acpi_processor   *pr = NULL;
        struct acpi_processor_cx *cx = NULL;
-       int                     next_state = 0;
-       int                     sleep_ticks = 0;
+       unsigned int                    next_state = 0;
+       unsigned int            sleep_ticks = 0;
        u32                     t1, t2 = 0;
 
        pr = processors[smp_processor_id()];
@@ -475,9 +471,9 @@ acpi_processor_idle (void)
         * Track the number of longs (time asleep is greater than threshold)
         * and promote when the count threshold is reached.  Note that bus
         * mastering activity may prevent promotions.
-        * Do not promote above acpi_cstate_limit.
+        * Do not promote above max_cstate.
         */
-       if (cx->promotion.state && (cx->promotion.state <= acpi_cstate_limit)) {
+       if (cx->promotion.state && (cx->promotion.state <= max_cstate)) {
                if (sleep_ticks > cx->promotion.threshold.ticks) {
                        cx->promotion.count++;
                        cx->demotion.count = 0;
@@ -515,10 +511,10 @@ acpi_processor_idle (void)
 
 end:
        /*
-        * Demote if current state exceeds acpi_cstate_limit
+        * Demote if current state exceeds max_cstate
         */
-       if (pr->power.state > acpi_cstate_limit) {
-               next_state = acpi_cstate_limit;
+       if (pr->power.state > max_cstate) {
+               next_state = max_cstate;
        }
 
        /*
@@ -672,11 +668,6 @@ acpi_processor_get_power_info (
                else if (errata.smp)
                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                "C2 not supported in SMP mode\n"));
-
-
-               else if (!c2) 
-                       printk(KERN_INFO "C2 disabled\n");
-
                /*
                 * Otherwise we've met all of our C2 requirements.
                 * Normalize the C2 latency to expidite policy.
@@ -732,9 +723,6 @@ acpi_processor_get_power_info (
                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                "C3 not supported on PIIX4 with Type-F DMA\n"));
                }
-               else if (!c3)
-                       printk(KERN_INFO "C3 disabled\n");
-
                /*
                 * Otherwise we've met all of our C3 requirements.  
                 * Normalize the C2 latency to expidite policy.  Enable
@@ -995,7 +983,7 @@ acpi_processor_get_performance_states (
        struct acpi_buffer      format = {sizeof("NNNNNN"), "NNNNNN"};
        struct acpi_buffer      state = {0, NULL};
        union acpi_object       *pss = NULL;
-       int                     i = 0;
+       unsigned int            i;
 
        ACPI_FUNCTION_TRACE("acpi_processor_get_performance_states");
 
@@ -1117,7 +1105,7 @@ static struct file_operations acpi_processor_perf_fops = {
 static int acpi_processor_perf_seq_show(struct seq_file *seq, void *offset)
 {
        struct acpi_processor   *pr = (struct acpi_processor *)seq->private;
-       int                     i = 0;
+       unsigned int            i;
 
        ACPI_FUNCTION_TRACE("acpi_processor_perf_seq_show");
 
@@ -1880,7 +1868,7 @@ static int acpi_processor_info_open_fs(struct inode *inode, struct file *file)
 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
 {
        struct acpi_processor   *pr = (struct acpi_processor *)seq->private;
-       int                     i = 0;
+       unsigned int            i;
 
        ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
 
@@ -1889,9 +1877,11 @@ static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
 
        seq_printf(seq, "active state:            C%d\n"
                        "default state:           C%d\n"
+                       "max_cstate:              C%d\n"
                        "bus master activity:     %08x\n",
                        pr->power.state,
                        pr->power.default_state,
+                       max_cstate,
                        pr->power.bm_activity);
 
        seq_puts(seq, "states:\n");
@@ -2478,17 +2468,22 @@ acpi_processor_remove (
        return_VALUE(0);
 }
 
-/* IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 
-   For now disable this. Probably a bug somewhere else. */
+/*
+ * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 
+ * For now disable this. Probably a bug somewhere else.
+ *
+ * To skip this limit, boot/load with a large max_cstate limit.
+ */
 static int no_c2c3(struct dmi_system_id *id)
 {
-       printk(KERN_INFO 
-              "%s detected - C2,C3 disabled. Overwrite with \"processor.c2=1 processor.c3=1\n\"",
-              id->ident);
-       if (c2 == -1) 
-               c2 = 0;
-       if (c3 == -1) 
-               c3 = 0; 
+       if (max_cstate > ACPI_C_STATES_MAX)
+               return 0;
+
+       printk(KERN_NOTICE PREFIX "%s detected - C2,C3 disabled."
+               " Override with \"processor.max_cstate=9\"\n", id->ident);
+
+       max_cstate = 1;
+
        return 0;
 }
 
@@ -2533,6 +2528,9 @@ acpi_processor_init (void)
 
        dmi_check_system(processor_dmi_table); 
 
+       if (max_cstate < ACPI_C_STATES_MAX)
+               printk(KERN_NOTICE "ACPI: processor limited to max C-state %d\n", max_cstate);
+
        return_VALUE(0);
 }
 
@@ -2556,6 +2554,6 @@ acpi_processor_exit (void)
 
 module_init(acpi_processor_init);
 module_exit(acpi_processor_exit);
-module_param_named(acpi_cstate_limit, acpi_cstate_limit, uint, 0);
+module_param_named(max_cstate, max_cstate, uint, 0);
 
 EXPORT_SYMBOL(acpi_processor_set_thermal_limit);

diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index dab7521d8ac6c0ff9ed1ffe8c00eaf91be83117c..700cafd2b5cc0c8e1f3da7c9eddf632580f44272 100644 (file)
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -17,7 +17,7 @@
 
 struct acpi_processor_cx_policy {
        u32                     count;
-       int                     state;
+       u32                     state;
        struct {
                u32                     time;
                u32                     ticks;
@@ -38,8 +38,8 @@ struct acpi_processor_cx {
 };
 
 struct acpi_processor_power {
-       int                     state;
-       int                     default_state;
+       u32                     state;
+       u32                     default_state;
        u32                     bm_activity;
        struct acpi_processor_cx states[ACPI_PROCESSOR_MAX_POWER];
 };

diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 5960e3c49fe79f6a8126f6315621643e419879b3..9cd73a47fc18a6ab154b730284da049e5e71bc89 100644 (file)
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -483,15 +483,15 @@ static inline int acpi_blacklisted(void)
  * 2: C2 okay, but not C3 etc.
  */
 
-extern unsigned int acpi_cstate_limit;
+extern unsigned int max_cstate;
 
 static inline unsigned int acpi_get_cstate_limit(void)
 {
-       return acpi_cstate_limit;
+       return max_cstate;
 }
 static inline void acpi_set_cstate_limit(unsigned int new_limit)
 {
-       acpi_cstate_limit = new_limit;
+       max_cstate = new_limit;
        return;
 }
 #else