[ACPI] enable C2 and C3 idle power states on SMP

http://bugzilla.kernel.org/show_bug.cgi?id=4401

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

3 files changed, 109 insertions, 66 deletions

diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index f4778747e889..e421842888b9 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -256,6 +256,43 @@ acpi_processor_errata (
 
 
 /* --------------------------------------------------------------------------
+                              Common ACPI processor fucntions
+   -------------------------------------------------------------------------- */
+
+/*
+ * _PDC is required for a BIOS-OS handshake for most of the newer
+ * ACPI processor features.
+ */
+
+int acpi_processor_set_pdc(struct acpi_processor *pr,
+                                struct acpi_object_list *pdc_in)
+{
+        acpi_status             status = AE_OK;
+        u32                     arg0_buf[3];
+        union acpi_object       arg0 = {ACPI_TYPE_BUFFER};
+        struct acpi_object_list no_object = {1, &arg0};
+        struct acpi_object_list *pdc;
+
+        ACPI_FUNCTION_TRACE("acpi_processor_set_pdc");
+
+        arg0.buffer.length = 12;
+        arg0.buffer.pointer = (u8 *) arg0_buf;
+        arg0_buf[0] = ACPI_PDC_REVISION_ID;
+        arg0_buf[1] = 0;
+        arg0_buf[2] = 0;
+
+        pdc = (pdc_in) ? pdc_in : &no_object;
+
+        status = acpi_evaluate_object(pr->handle, "_PDC", pdc, NULL);
+
+        if ((ACPI_FAILURE(status)) && (pdc_in))
+                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Error evaluating _PDC, using legacy perf. control...\n"));
+
+        return_VALUE(status);
+}
+
+
+/* --------------------------------------------------------------------------
                               FS Interface (/proc)
    -------------------------------------------------------------------------- */
 
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 79d5ca3066c6..8f038cd29477 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -6,6 +6,8 @@
  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
  *                      - Added processor hotplug support
+ *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ *                      - Added support for C3 on SMP
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
@@ -142,7 +144,7 @@ acpi_processor_power_activate (
                 switch (old->type) {
                 case ACPI_STATE_C3:
                         /* Disable bus master reload */
-                        if (new->type != ACPI_STATE_C3)
+                        if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
                                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0, ACPI_MTX_DO_NOT_LOCK);
                         break;
                 }
@@ -152,7 +154,7 @@ acpi_processor_power_activate (
         switch (new->type) {
         case ACPI_STATE_C3:
                 /* Enable bus master reload */
-                if (old->type != ACPI_STATE_C3)
+                if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
                         acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1, ACPI_MTX_DO_NOT_LOCK);
                 break;
         }
@@ -163,6 +165,9 @@ acpi_processor_power_activate (
 }
 
 
+static atomic_t         c3_cpu_count;
+
+
 static void acpi_processor_idle (void)
 {
         struct acpi_processor   *pr = NULL;
@@ -297,8 +302,22 @@ static void acpi_processor_idle (void)
                 break;
 
         case ACPI_STATE_C3:
-                /* Disable bus master arbitration */
-                acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1, ACPI_MTX_DO_NOT_LOCK);
+                
+                if (pr->flags.bm_check) {
+                        if (atomic_inc_return(&c3_cpu_count) ==
+                                        num_online_cpus()) {
+                                /*
+                                 * All CPUs are trying to go to C3
+                                 * Disable bus master arbitration
+                                 */
+                                acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1,
+                                        ACPI_MTX_DO_NOT_LOCK);
+                        }
+                } else {
+                        /* SMP with no shared cache... Invalidate cache  */
+                        ACPI_FLUSH_CPU_CACHE();
+                }
+                
                 /* Get start time (ticks) */
                 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
                 /* Invoke C3 */
@@ -307,8 +326,12 @@ static void acpi_processor_idle (void)
                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
                 /* Get end time (ticks) */
                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
-                /* Enable bus master arbitration */
-                acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0, ACPI_MTX_DO_NOT_LOCK);
+                if (pr->flags.bm_check) {
+                        /* Enable bus master arbitration */
+                        atomic_dec(&c3_cpu_count);
+                        acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0, ACPI_MTX_DO_NOT_LOCK);
+                }
+
                 /* Re-enable interrupts */
                 local_irq_enable();
                 /* Compute time (ticks) that we were actually asleep */
@@ -552,9 +575,6 @@ static int acpi_processor_get_power_info_cst (struct acpi_processor *pr)
 
         ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
 
-        if (errata.smp)
-                return_VALUE(-ENODEV);
-
         if (nocst)
                 return_VALUE(-ENODEV);
 
@@ -687,13 +707,6 @@ static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
                 return_VOID;
         }
 
-        /* We're (currently) only supporting C2 on UP */
-        else if (errata.smp) {
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-                                  "C2 not supported in SMP mode\n"));
-                return_VOID;
-        }
-
         /*
          * Otherwise we've met all of our C2 requirements.
          * Normalize the C2 latency to expidite policy
@@ -709,6 +722,8 @@ static void acpi_processor_power_verify_c3(
         struct acpi_processor *pr,
         struct acpi_processor_cx *cx)
 {
+        static int bm_check_flag;
+
         ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
 
         if (!cx->address)
@@ -725,20 +740,6 @@ static void acpi_processor_power_verify_c3(
                 return_VOID;
         }
 
-        /* bus mastering control is necessary */
-        else if (!pr->flags.bm_control) {
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-                                  "C3 support requires bus mastering control\n"));
-                return_VOID;
-        }
-
-        /* We're (currently) only supporting C2 on UP */
-        else if (errata.smp) {
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-                                  "C3 not supported in SMP mode\n"));
-                return_VOID;
-        }
-
         /*
          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
          * DMA transfers are used by any ISA device to avoid livelock.
@@ -752,6 +753,39 @@ static void acpi_processor_power_verify_c3(
                 return_VOID;
         }
 
+        /* All the logic here assumes flags.bm_check is same across all CPUs */
+        if (!bm_check_flag) {
+                /* Determine whether bm_check is needed based on CPU  */
+                acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
+                bm_check_flag = pr->flags.bm_check;
+        } else {
+                pr->flags.bm_check = bm_check_flag;
+        }
+
+        if (pr->flags.bm_check) {
+                printk("Disabling BM access before entering C3\n");
+                /* bus mastering control is necessary */
+                if (!pr->flags.bm_control) {
+                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                          "C3 support requires bus mastering control\n"));
+                        return_VOID;
+                }
+        } else {
+                printk("Invalidating cache before entering C3\n");
+                /*
+                 * WBINVD should be set in fadt, for C3 state to be
+                 * supported on when bm_check is not required.
+                 */
+                if (acpi_fadt.wb_invd != 1) {
+                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                          "Cache invalidation should work properly"
+                          " for C3 to be enabled on SMP systems\n"));
+                        return_VOID;
+                }
+                acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
+                                0, ACPI_MTX_DO_NOT_LOCK);
+        }
+
         /*
          * Otherwise we've met all of our C3 requirements.
          * Normalize the C3 latency to expidite policy.  Enable
@@ -760,7 +794,6 @@ static void acpi_processor_power_verify_c3(
          */
         cx->valid = 1;
         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
-        pr->flags.bm_check = 1;
 
         return_VOID;
 }
@@ -848,7 +881,7 @@ int acpi_processor_cst_has_changed (struct acpi_processor *pr)
         if (!pr)
                 return_VALUE(-EINVAL);
 
-        if (errata.smp || nocst) {
+        if ( nocst) {
                 return_VALUE(-ENODEV);
         }
 
@@ -948,7 +981,6 @@ static struct file_operations acpi_processor_power_fops = {
         .release        = single_release,
 };
 
-
 int acpi_processor_power_init(struct acpi_processor *pr, struct acpi_device *device)
 {
         acpi_status             status = 0;
@@ -965,7 +997,10 @@ int acpi_processor_power_init(struct acpi_processor *pr, struct acpi_device *dev
                 first_run++;
         }
 
-        if (!errata.smp && (pr->id == 0) && acpi_fadt.cst_cnt && !nocst) {
+        if (!pr)
+                return_VALUE(-EINVAL);
+
+        if (acpi_fadt.cst_cnt && !nocst) {
                 status = acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
                 if (ACPI_FAILURE(status)) {
                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
@@ -973,6 +1008,8 @@ int acpi_processor_power_init(struct acpi_processor *pr, struct acpi_device *dev
                 }
         }
 
+        acpi_processor_power_init_pdc(&(pr->power), pr->id);
+        acpi_processor_set_pdc(pr, pr->power.pdc);
         acpi_processor_get_power_info(pr);
 
         /*
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index a9a1a8fe3199..1f0d6256302f 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -165,37 +165,6 @@ void acpi_processor_ppc_exit(void) {
         acpi_processor_ppc_status &= ~PPC_REGISTERED;
 }
 
-/*
- * when registering a cpufreq driver with this ACPI processor driver, the
- * _PCT and _PSS structures are read out and written into struct
- * acpi_processor_performance.
- */
-static int acpi_processor_set_pdc (struct acpi_processor *pr)
-{
-        acpi_status             status = AE_OK;
-        u32                     arg0_buf[3];
-        union acpi_object       arg0 = {ACPI_TYPE_BUFFER};
-        struct acpi_object_list no_object = {1, &arg0};
-        struct acpi_object_list *pdc;
-
-        ACPI_FUNCTION_TRACE("acpi_processor_set_pdc");
-
-        arg0.buffer.length = 12;
-        arg0.buffer.pointer = (u8 *) arg0_buf;
-        arg0_buf[0] = ACPI_PDC_REVISION_ID;
-        arg0_buf[1] = 0;
-        arg0_buf[2] = 0;
-
-        pdc = (pr->performance->pdc) ? pr->performance->pdc : &no_object;
-
-        status = acpi_evaluate_object(pr->handle, "_PDC", pdc, NULL);
-
-        if ((ACPI_FAILURE(status)) && (pr->performance->pdc))
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Error evaluating _PDC, using legacy perf. control...\n"));
-
-        return_VALUE(status);
-}
-
 
 static int
 acpi_processor_get_performance_control (
@@ -357,7 +326,7 @@ acpi_processor_get_performance_info (
         if (!pr || !pr->performance || !pr->handle)
                 return_VALUE(-EINVAL);
 
-        acpi_processor_set_pdc(pr);
+        acpi_processor_set_pdc(pr, pr->performance->pdc);
 
         status = acpi_get_handle(pr->handle, "_PCT", &handle);
         if (ACPI_FAILURE(status)) {