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-rw-r--r--arch/s390/include/asm/sigp.h40
-rw-r--r--arch/s390/include/asm/smp.h24
-rw-r--r--arch/s390/lib/spinlock.c53
3 files changed, 80 insertions, 37 deletions
diff --git a/arch/s390/include/asm/sigp.h b/arch/s390/include/asm/sigp.h
index 8aa46ce4229c..e3bffd4e2d66 100644
--- a/arch/s390/include/asm/sigp.h
+++ b/arch/s390/include/asm/sigp.h
@@ -25,29 +25,28 @@ static inline int cpu_logical_map(int cpu)
25} 25}
26 26
27enum { 27enum {
28 sigp_unassigned=0x0, 28 sigp_sense = 1,
29 sigp_sense, 29 sigp_external_call = 2,
30 sigp_external_call, 30 sigp_emergency_signal = 3,
31 sigp_emergency_signal, 31 sigp_start = 4,
32 sigp_start, 32 sigp_stop = 5,
33 sigp_stop, 33 sigp_restart = 6,
34 sigp_restart, 34 sigp_stop_and_store_status = 9,
35 sigp_unassigned1, 35 sigp_initial_cpu_reset = 11,
36 sigp_unassigned2, 36 sigp_cpu_reset = 12,
37 sigp_stop_and_store_status, 37 sigp_set_prefix = 13,
38 sigp_unassigned3, 38 sigp_store_status_at_address = 14,
39 sigp_initial_cpu_reset, 39 sigp_store_extended_status_at_address = 15,
40 sigp_cpu_reset, 40 sigp_set_architecture = 18,
41 sigp_set_prefix, 41 sigp_conditional_emergency_signal = 19,
42 sigp_store_status_at_address, 42 sigp_sense_running = 21,
43 sigp_store_extended_status_at_address
44}; 43};
45 44
46enum { 45enum {
47 sigp_order_code_accepted=0, 46 sigp_order_code_accepted = 0,
48 sigp_status_stored, 47 sigp_status_stored = 1,
49 sigp_busy, 48 sigp_busy = 2,
50 sigp_not_operational 49 sigp_not_operational = 3,
51}; 50};
52 51
53/* 52/*
@@ -57,7 +56,6 @@ enum {
57 ec_schedule = 0, 56 ec_schedule = 0,
58 ec_call_function, 57 ec_call_function,
59 ec_call_function_single, 58 ec_call_function_single,
60 ec_bit_last
61}; 59};
62 60
63/* 61/*
diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h
index c2d0e638f892..edc03cb9cd79 100644
--- a/arch/s390/include/asm/smp.h
+++ b/arch/s390/include/asm/smp.h
@@ -36,6 +36,28 @@ extern void smp_switch_to_cpu(void (*)(void *), void *, unsigned long sp,
36 int from, int to); 36 int from, int to);
37extern void smp_restart_cpu(void); 37extern void smp_restart_cpu(void);
38 38
39/*
40 * returns 1 if (virtual) cpu is scheduled
41 * returns 0 otherwise
42 */
43static inline int smp_vcpu_scheduled(int cpu)
44{
45 u32 status;
46
47 switch (sigp_ps(&status, 0, cpu, sigp_sense_running)) {
48 case sigp_status_stored:
49 /* Check for running status */
50 if (status & 0x400)
51 return 0;
52 break;
53 case sigp_not_operational:
54 return 0;
55 default:
56 break;
57 }
58 return 1;
59}
60
39#else /* CONFIG_SMP */ 61#else /* CONFIG_SMP */
40 62
41static inline void smp_switch_to_ipl_cpu(void (*func)(void *), void *data) 63static inline void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
@@ -43,6 +65,8 @@ static inline void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
43 func(data); 65 func(data);
44} 66}
45 67
68#define smp_vcpu_scheduled (1)
69
46#endif /* CONFIG_SMP */ 70#endif /* CONFIG_SMP */
47 71
48#ifdef CONFIG_HOTPLUG_CPU 72#ifdef CONFIG_HOTPLUG_CPU
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index cff327f109a8..91754ffb9203 100644
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -43,16 +43,24 @@ void arch_spin_lock_wait(arch_spinlock_t *lp)
43{ 43{
44 int count = spin_retry; 44 int count = spin_retry;
45 unsigned int cpu = ~smp_processor_id(); 45 unsigned int cpu = ~smp_processor_id();
46 unsigned int owner;
46 47
47 while (1) { 48 while (1) {
48 if (count-- <= 0) { 49 owner = lp->owner_cpu;
49 unsigned int owner = lp->owner_cpu; 50 if (!owner || smp_vcpu_scheduled(~owner)) {
50 if (owner != 0) 51 for (count = spin_retry; count > 0; count--) {
51 _raw_yield_cpu(~owner); 52 if (arch_spin_is_locked(lp))
52 count = spin_retry; 53 continue;
54 if (_raw_compare_and_swap(&lp->owner_cpu, 0,
55 cpu) == 0)
56 return;
57 }
58 if (MACHINE_IS_LPAR)
59 continue;
53 } 60 }
54 if (arch_spin_is_locked(lp)) 61 owner = lp->owner_cpu;
55 continue; 62 if (owner)
63 _raw_yield_cpu(~owner);
56 if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0) 64 if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0)
57 return; 65 return;
58 } 66 }
@@ -63,17 +71,27 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags)
63{ 71{
64 int count = spin_retry; 72 int count = spin_retry;
65 unsigned int cpu = ~smp_processor_id(); 73 unsigned int cpu = ~smp_processor_id();
74 unsigned int owner;
66 75
67 local_irq_restore(flags); 76 local_irq_restore(flags);
68 while (1) { 77 while (1) {
69 if (count-- <= 0) { 78 owner = lp->owner_cpu;
70 unsigned int owner = lp->owner_cpu; 79 if (!owner || smp_vcpu_scheduled(~owner)) {
71 if (owner != 0) 80 for (count = spin_retry; count > 0; count--) {
72 _raw_yield_cpu(~owner); 81 if (arch_spin_is_locked(lp))
73 count = spin_retry; 82 continue;
83 local_irq_disable();
84 if (_raw_compare_and_swap(&lp->owner_cpu, 0,
85 cpu) == 0)
86 return;
87 local_irq_restore(flags);
88 }
89 if (MACHINE_IS_LPAR)
90 continue;
74 } 91 }
75 if (arch_spin_is_locked(lp)) 92 owner = lp->owner_cpu;
76 continue; 93 if (owner)
94 _raw_yield_cpu(~owner);
77 local_irq_disable(); 95 local_irq_disable();
78 if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0) 96 if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0)
79 return; 97 return;
@@ -100,8 +118,11 @@ EXPORT_SYMBOL(arch_spin_trylock_retry);
100void arch_spin_relax(arch_spinlock_t *lock) 118void arch_spin_relax(arch_spinlock_t *lock)
101{ 119{
102 unsigned int cpu = lock->owner_cpu; 120 unsigned int cpu = lock->owner_cpu;
103 if (cpu != 0) 121 if (cpu != 0) {
104 _raw_yield_cpu(~cpu); 122 if (MACHINE_IS_VM || MACHINE_IS_KVM ||
123 !smp_vcpu_scheduled(~cpu))
124 _raw_yield_cpu(~cpu);
125 }
105} 126}
106EXPORT_SYMBOL(arch_spin_relax); 127EXPORT_SYMBOL(arch_spin_relax);
107 128
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-25 19:59:48 -0500