arch/arm/mach-mt8127/hotplug.c

   1 #include <linux/errno.h>    //EPERM
   2 #include <asm/cacheflush.h> //flush_cache_all
   3 #include <mach/hotplug.h>
   4 #ifdef CONFIG_HOTPLUG_WITH_POWER_CTRL
   5 #include <mach/mt_spm_mtcmos.h>
   6 #endif
   7 #include <mach/mt_spm_idle.h>
   8 #include <mach/wd_api.h>
   9 #ifdef CONFIG_MTK_IN_HOUSE_TEE_SUPPORT
  10 #include <trustzone/kree/tz_pm.h>
  11 #endif
  12
  13 /*
  14  * extern function
  15  */
  16 extern void __disable_dcache(void);         //definition in mt_cache_v7.S
  17 extern void __enable_dcache(void);          //definition in mt_cache_v7.S
  18 extern void __inner_clean_dcache_L2(void);  //definition in mt_cache_v7.S
  19 extern void inner_dcache_flush_L1(void);    //definition in inner_cache.c
  20 extern void __switch_to_smp(void);          //definition in mt_hotplug.S
  21 extern void __switch_to_amp(void);          //definition in mt_hotplug.S
  22
  23
  24
  25 /*
  26  * global variable
  27  */
  28 atomic_t hotplug_cpu_count = ATOMIC_INIT(1);
  29
  30
  31
  32 #ifndef CONFIG_MTK_IN_HOUSE_TEE_SUPPORT
  33 /*
  34  * static function
  35  */
  36 static inline void cpu_enter_lowpower(unsigned int cpu)
  37 {
  38     //HOTPLUG_INFO("cpu_enter_lowpower\n");
  39
  40 #ifdef SPM_MCDI_FUNC
  41     spm_hot_plug_out_after(cpu);
  42 #endif
  43
  44     /* Clear the SCTLR C bit to prevent further data cache allocation */
  45     __disable_dcache();
  46
  47     /* Clean and invalidate all data from the L1 data cache */
  48     inner_dcache_flush_L1();
  49     //Just flush the cache.
  50     //flush_cache_all();
  51
  52     /* Clean all data from the L2 data cache */
  53     __inner_clean_dcache_L2();
  54
  55     /* Execute a CLREX instruction */
  56     __asm__ __volatile__("clrex");
  57
  58     /* Switch the processor from SMP mode to AMP mode by clearing the ACTLR SMP bit */
  59     __switch_to_amp();
  60 }
  61
  62 static inline void cpu_leave_lowpower(unsigned int cpu)
  63 {
  64     //HOTPLUG_INFO("cpu_leave_lowpower\n");
  65
  66     /* Set the ACTLR.SMP bit to 1 for SMP mode */
  67     __switch_to_smp();
  68
  69     /* Enable dcache */
  70     __enable_dcache();
  71 }
  72
  73 static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
  74 {
  75     /* Just enter wfi for now. TODO: Properly shut off the cpu. */
  76     for (;;) {
  77
  78         /* Execute an ISB instruction to ensure that all of the CP15 register changes from the previous steps have been committed */
  79         isb();
  80
  81         /* Execute a DSB instruction to ensure that all cache, TLB and branch predictor maintenance operations issued by any processor in the multiprocessor device before the SMP bit was cleared have completed */
  82         dsb();
  83
  84         /*
  85          * here's the WFI
  86          */
  87         __asm__ __volatile__("wfi");
  88
  89         if (pen_release == cpu) {
  90             /*
  91              * OK, proper wakeup, we're done
  92              */
  93             break;
  94         }
  95
  96         /*
  97          * Getting here, means that we have come out of WFI without
  98          * having been woken up - this shouldn't happen
  99          *
 100          * Just note it happening - when we're woken, we can report
 101          * its occurrence.
 102          */
 103         (*spurious)++;
 104     }
 105 }
 106 #else // defined(CONFIG_MTK_IN_HOUSE_TEE_SUPPORT)
 107 static inline void cpu_enter_lowpower(unsigned int cpu) { return; }
 108 static inline void cpu_leave_lowpower(unsigned int cpu) { return; }
 109 static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
 110 {
 111     /* TEE PM to do low power */
 112     kree_pm_cpu_lowpower(&pen_release, cpu);
 113     /*
 114      * Getting here, means that we have come out of WFI without
 115      * having been woken up - this shouldn't happen
 116      *
 117      * Just note it happening - when we're woken, we can report
 118      * its occurrence.
 119      */
 120     (*spurious)++;
 121 }
 122 #endif
 123
 124
 125 /*
 126  * platform_cpu_kill:
 127  * @cpu:
 128  * Return TBD.
 129  */
 130 int platform_cpu_kill(unsigned int cpu)
 131 {
 132     HOTPLUG_INFO("platform_cpu_kill, cpu: %d\n", cpu);
 133
 134 #ifdef CONFIG_HOTPLUG_WITH_POWER_CTRL
 135     switch(cpu)
 136     {
 137         case 1:
 138             spm_mtcmos_ctrl_cpu1(STA_POWER_DOWN, 1);
 139             break;
 140         case 2:
 141             spm_mtcmos_ctrl_cpu2(STA_POWER_DOWN, 1);
 142             break;
 143         case 3:
 144             spm_mtcmos_ctrl_cpu3(STA_POWER_DOWN, 1);
 145             break;
 146         default:
 147             break;
 148     }
 149 #endif
 150     atomic_dec(&hotplug_cpu_count);
 151
 152     return 1;
 153 }
 154
 155 /*
 156  * platform_cpu_die: shutdown a CPU
 157  * @cpu:
 158  */
 159 void platform_cpu_die(unsigned int cpu)
 160 {
 161     int spurious = 0;
 162     struct wd_api *wd_api = NULL;
 163
 164     HOTPLUG_INFO("platform_cpu_die, cpu: %d\n", cpu);
 165
 166     get_wd_api(&wd_api);
 167     if (wd_api)
 168         wd_api->wd_cpu_hot_plug_off_notify(cpu);
 169
 170     /*
 171      * we're ready for shutdown now, so do it
 172      */
 173     cpu_enter_lowpower(cpu);
 174     platform_do_lowpower(cpu, &spurious);
 175
 176     /*
 177      * bring this CPU back into the world of cache
 178      * coherency, and then restore interrupts
 179      */
 180     cpu_leave_lowpower(cpu);
 181
 182     if (spurious)
 183         HOTPLUG_INFO("platform_do_lowpower, spurious wakeup call, cpu: %d, spurious: %d\n", cpu, spurious);
 184 }
 185
 186 /*
 187  * platform_cpu_disable:
 188  * @cpu:
 189  * Return error code.
 190  */
 191 int platform_cpu_disable(unsigned int cpu)
 192 {
 193     /*
 194     * we don't allow CPU 0 to be shutdown (it is still too special
 195     * e.g. clock tick interrupts)
 196     */
 197     HOTPLUG_INFO("platform_cpu_disable, cpu: %d\n", cpu);
 198     return cpu == 0 ? -EPERM : 0;
 199 }