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-rw-r--r--arch/s390/include/asm/setup.h3
-rw-r--r--arch/s390/kernel/early.c18
-rw-r--r--arch/s390/lib/spinlock.c52
3 files changed, 66 insertions, 7 deletions
diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h
index 7736fdd72595..b8d1e54b4733 100644
--- a/arch/s390/include/asm/setup.h
+++ b/arch/s390/include/asm/setup.h
@@ -57,6 +57,7 @@ extern void detect_memory_memblock(void);
#define MACHINE_FLAG_TE (1UL << 15)
#define MACHINE_FLAG_TLB_LC (1UL << 17)
#define MACHINE_FLAG_VX (1UL << 18)
+#define MACHINE_FLAG_CAD (1UL << 19)
#define MACHINE_IS_VM (S390_lowcore.machine_flags & MACHINE_FLAG_VM)
#define MACHINE_IS_KVM (S390_lowcore.machine_flags & MACHINE_FLAG_KVM)
@@ -80,6 +81,7 @@ extern void detect_memory_memblock(void);
#define MACHINE_HAS_TE (0)
#define MACHINE_HAS_TLB_LC (0)
#define MACHINE_HAS_VX (0)
+#define MACHINE_HAS_CAD (0)
#else /* CONFIG_64BIT */
#define MACHINE_HAS_IEEE (1)
#define MACHINE_HAS_CSP (1)
@@ -93,6 +95,7 @@ extern void detect_memory_memblock(void);
#define MACHINE_HAS_TE (S390_lowcore.machine_flags & MACHINE_FLAG_TE)
#define MACHINE_HAS_TLB_LC (S390_lowcore.machine_flags & MACHINE_FLAG_TLB_LC)
#define MACHINE_HAS_VX (S390_lowcore.machine_flags & MACHINE_FLAG_VX)
+#define MACHINE_HAS_CAD (S390_lowcore.machine_flags & MACHINE_FLAG_CAD)
#endif /* CONFIG_64BIT */
/*
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 302ac1f7f8e7..70a329450901 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -393,9 +393,27 @@ static __init void detect_machine_facilities(void)
S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
if (test_facility(129))
S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
+ if (test_facility(128))
+ S390_lowcore.machine_flags |= MACHINE_FLAG_CAD;
#endif
}
+static int __init nocad_setup(char *str)
+{
+ S390_lowcore.machine_flags &= ~MACHINE_FLAG_CAD;
+ return 0;
+}
+early_param("nocad", nocad_setup);
+
+static int __init cad_init(void)
+{
+ if (MACHINE_HAS_CAD)
+ /* Enable problem state CAD. */
+ __ctl_set_bit(2, 3);
+ return 0;
+}
+early_initcall(cad_init);
+
static __init void rescue_initrd(void)
{
#ifdef CONFIG_BLK_DEV_INITRD
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index 034a35a3e9c1..d6c9991f7797 100644
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -12,7 +12,15 @@
#include <linux/smp.h>
#include <asm/io.h>
-int spin_retry = 1000;
+int spin_retry = -1;
+
+static int __init spin_retry_init(void)
+{
+ if (spin_retry < 0)
+ spin_retry = MACHINE_HAS_CAD ? 10 : 1000;
+ return 0;
+}
+early_initcall(spin_retry_init);
/**
* spin_retry= parameter
@@ -24,6 +32,11 @@ static int __init spin_retry_setup(char *str)
}
__setup("spin_retry=", spin_retry_setup);
+static inline void _raw_compare_and_delay(unsigned int *lock, unsigned int old)
+{
+ asm(".insn rsy,0xeb0000000022,%0,0,%1" : : "d" (old), "Q" (*lock));
+}
+
void arch_spin_lock_wait(arch_spinlock_t *lp)
{
unsigned int cpu = SPINLOCK_LOCKVAL;
@@ -46,6 +59,8 @@ void arch_spin_lock_wait(arch_spinlock_t *lp)
/* Loop for a while on the lock value. */
count = spin_retry;
do {
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&lp->lock, owner);
owner = ACCESS_ONCE(lp->lock);
} while (owner && count-- > 0);
if (!owner)
@@ -84,6 +99,8 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags)
/* Loop for a while on the lock value. */
count = spin_retry;
do {
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&lp->lock, owner);
owner = ACCESS_ONCE(lp->lock);
} while (owner && count-- > 0);
if (!owner)
@@ -100,11 +117,19 @@ EXPORT_SYMBOL(arch_spin_lock_wait_flags);
int arch_spin_trylock_retry(arch_spinlock_t *lp)
{
+ unsigned int cpu = SPINLOCK_LOCKVAL;
+ unsigned int owner;
int count;
- for (count = spin_retry; count > 0; count--)
- if (arch_spin_trylock_once(lp))
- return 1;
+ for (count = spin_retry; count > 0; count--) {
+ owner = ACCESS_ONCE(lp->lock);
+ /* Try to get the lock if it is free. */
+ if (!owner) {
+ if (_raw_compare_and_swap(&lp->lock, 0, cpu))
+ return 1;
+ } else if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&lp->lock, owner);
+ }
return 0;
}
EXPORT_SYMBOL(arch_spin_trylock_retry);
@@ -126,8 +151,11 @@ void _raw_read_lock_wait(arch_rwlock_t *rw)
}
old = ACCESS_ONCE(rw->lock);
owner = ACCESS_ONCE(rw->owner);
- if ((int) old < 0)
+ if ((int) old < 0) {
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&rw->lock, old);
continue;
+ }
if (_raw_compare_and_swap(&rw->lock, old, old + 1))
return;
}
@@ -141,8 +169,11 @@ int _raw_read_trylock_retry(arch_rwlock_t *rw)
while (count-- > 0) {
old = ACCESS_ONCE(rw->lock);
- if ((int) old < 0)
+ if ((int) old < 0) {
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&rw->lock, old);
continue;
+ }
if (_raw_compare_and_swap(&rw->lock, old, old + 1))
return 1;
}
@@ -173,6 +204,8 @@ void _raw_write_lock_wait(arch_rwlock_t *rw, unsigned int prev)
}
if ((old & 0x7fffffff) == 0 && (int) prev >= 0)
break;
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&rw->lock, old);
}
}
EXPORT_SYMBOL(_raw_write_lock_wait);
@@ -201,6 +234,8 @@ void _raw_write_lock_wait(arch_rwlock_t *rw)
smp_rmb();
if ((old & 0x7fffffff) == 0 && (int) prev >= 0)
break;
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&rw->lock, old);
}
}
EXPORT_SYMBOL(_raw_write_lock_wait);
@@ -214,8 +249,11 @@ int _raw_write_trylock_retry(arch_rwlock_t *rw)
while (count-- > 0) {
old = ACCESS_ONCE(rw->lock);
- if (old)
+ if (old) {
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&rw->lock, old);
continue;
+ }
if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000))
return 1;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-14 11:59:34 +0000