s390: add SMT support

[firefly-linux-kernel-4.4.55.git] / arch / s390 / kernel / vtime.c

diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index e34122e539a16bad4e5727f881f982e4829cd8f0..e53d3595a7c8c1a54400d5fb3e984004cd864219 100644 (file)
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -15,6 +15,8 @@
 #include <asm/cputime.h>
 #include <asm/vtimer.h>
 #include <asm/vtime.h>
+#include <asm/cpu_mf.h>
+#include <asm/smp.h>
 
 static void virt_timer_expire(void);
 
@@ -23,6 +25,10 @@ static DEFINE_SPINLOCK(virt_timer_lock);
 static atomic64_t virt_timer_current;
 static atomic64_t virt_timer_elapsed;
 
+static DEFINE_PER_CPU(u64, mt_cycles[32]);
+static DEFINE_PER_CPU(u64, mt_scaling_mult) = { 1 };
+static DEFINE_PER_CPU(u64, mt_scaling_div) = { 1 };
+
 static inline u64 get_vtimer(void)
 {
        u64 timer;
@@ -61,6 +67,8 @@ static int do_account_vtime(struct task_struct *tsk, int hardirq_offset)
 {
        struct thread_info *ti = task_thread_info(tsk);
        u64 timer, clock, user, system, steal;
+       u64 user_scaled, system_scaled;
+       int i;
 
        timer = S390_lowcore.last_update_timer;
        clock = S390_lowcore.last_update_clock;
@@ -76,15 +84,49 @@ static int do_account_vtime(struct task_struct *tsk, int hardirq_offset)
        S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer;
        S390_lowcore.steal_timer += S390_lowcore.last_update_clock - clock;
 
+       /* Do MT utilization calculation */
+       if (smp_cpu_mtid) {
+               u64 cycles_new[32], *cycles_old;
+               u64 delta, mult, div;
+
+               cycles_old = this_cpu_ptr(mt_cycles);
+               if (stcctm5(smp_cpu_mtid + 1, cycles_new) < 2) {
+                       mult = div = 0;
+                       for (i = 0; i <= smp_cpu_mtid; i++) {
+                               delta = cycles_new[i] - cycles_old[i];
+                               mult += delta;
+                               div += (i + 1) * delta;
+                       }
+                       if (mult > 0) {
+                               /* Update scaling factor */
+                               __this_cpu_write(mt_scaling_mult, mult);
+                               __this_cpu_write(mt_scaling_div, div);
+                               memcpy(cycles_old, cycles_new,
+                                      sizeof(u64) * (smp_cpu_mtid + 1));
+                       }
+               }
+       }
+
        user = S390_lowcore.user_timer - ti->user_timer;
        S390_lowcore.steal_timer -= user;
        ti->user_timer = S390_lowcore.user_timer;
-       account_user_time(tsk, user, user);
 
        system = S390_lowcore.system_timer - ti->system_timer;
        S390_lowcore.steal_timer -= system;
        ti->system_timer = S390_lowcore.system_timer;
-       account_system_time(tsk, hardirq_offset, system, system);
+
+       user_scaled = user;
+       system_scaled = system;
+       /* Do MT utilization scaling */
+       if (smp_cpu_mtid) {
+               u64 mult = __this_cpu_read(mt_scaling_mult);
+               u64 div = __this_cpu_read(mt_scaling_div);
+
+               user_scaled = (user_scaled * mult) / div;
+               system_scaled = (system_scaled * mult) / div;
+       }
+       account_user_time(tsk, user, user_scaled);
+       account_system_time(tsk, hardirq_offset, system, system_scaled);
 
        steal = S390_lowcore.steal_timer;
        if ((s64) steal > 0) {
@@ -126,7 +168,7 @@ void vtime_account_user(struct task_struct *tsk)
 void vtime_account_irq_enter(struct task_struct *tsk)
 {
        struct thread_info *ti = task_thread_info(tsk);
-       u64 timer, system;
+       u64 timer, system, system_scaled;
 
        timer = S390_lowcore.last_update_timer;
        S390_lowcore.last_update_timer = get_vtimer();
@@ -135,7 +177,15 @@ void vtime_account_irq_enter(struct task_struct *tsk)
        system = S390_lowcore.system_timer - ti->system_timer;
        S390_lowcore.steal_timer -= system;
        ti->system_timer = S390_lowcore.system_timer;
-       account_system_time(tsk, 0, system, system);
+       system_scaled = system;
+       /* Do MT utilization scaling */
+       if (smp_cpu_mtid) {
+               u64 mult = __this_cpu_read(mt_scaling_mult);
+               u64 div = __this_cpu_read(mt_scaling_div);
+
+               system_scaled = (system_scaled * mult) / div;
+       }
+       account_system_time(tsk, 0, system, system_scaled);
 
        virt_timer_forward(system);
 }