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Diffstat (limited to 'arch/s390/lib')
-rw-r--r--arch/s390/lib/delay.c2
-rw-r--r--arch/s390/lib/spinlock.c87
-rw-r--r--arch/s390/lib/uaccess.c38
3 files changed, 78 insertions, 49 deletions
diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c
index 92e90e40b6fb..7f17555ad4d5 100644
--- a/arch/s390/lib/delay.c
+++ b/arch/s390/lib/delay.c
@@ -57,7 +57,7 @@ static void __udelay_enabled(unsigned long long usecs)
end = get_tod_clock_fast() + (usecs << 12);
do {
clock_saved = 0;
- if (end < S390_lowcore.clock_comparator) {
+ if (tod_after(S390_lowcore.clock_comparator, end)) {
clock_saved = local_tick_disable();
set_clock_comparator(end);
}
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index ffb15bd4c593..b12663d653d8 100644
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -32,42 +32,63 @@ static int __init spin_retry_setup(char *str)
}
__setup("spin_retry=", spin_retry_setup);
+static inline int arch_load_niai4(int *lock)
+{
+ int owner;
+
+ asm volatile(
+#ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
+ " .long 0xb2fa0040\n" /* NIAI 4 */
+#endif
+ " l %0,%1\n"
+ : "=d" (owner) : "Q" (*lock) : "memory");
+ return owner;
+}
+
+static inline int arch_cmpxchg_niai8(int *lock, int old, int new)
+{
+ int expected = old;
+
+ asm volatile(
+#ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
+ " .long 0xb2fa0080\n" /* NIAI 8 */
+#endif
+ " cs %0,%3,%1\n"
+ : "=d" (old), "=Q" (*lock)
+ : "0" (old), "d" (new), "Q" (*lock)
+ : "cc", "memory");
+ return expected == old;
+}
+
void arch_spin_lock_wait(arch_spinlock_t *lp)
{
int cpu = SPINLOCK_LOCKVAL;
- int owner, count, first_diag;
+ int owner, count;
+
+ /* Pass the virtual CPU to the lock holder if it is not running */
+ owner = arch_load_niai4(&lp->lock);
+ if (owner && arch_vcpu_is_preempted(~owner))
+ smp_yield_cpu(~owner);
- first_diag = 1;
+ count = spin_retry;
while (1) {
- owner = ACCESS_ONCE(lp->lock);
+ owner = arch_load_niai4(&lp->lock);
/* Try to get the lock if it is free. */
if (!owner) {
- if (__atomic_cmpxchg_bool(&lp->lock, 0, cpu))
+ if (arch_cmpxchg_niai8(&lp->lock, 0, cpu))
return;
continue;
}
- /* First iteration: check if the lock owner is running. */
- if (first_diag && arch_vcpu_is_preempted(~owner)) {
- smp_yield_cpu(~owner);
- first_diag = 0;
+ if (count-- >= 0)
continue;
- }
- /* Loop for a while on the lock value. */
count = spin_retry;
- do {
- owner = ACCESS_ONCE(lp->lock);
- } while (owner && count-- > 0);
- if (!owner)
- continue;
/*
* For multiple layers of hypervisors, e.g. z/VM + LPAR
* yield the CPU unconditionally. For LPAR rely on the
* sense running status.
*/
- if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(~owner)) {
+ if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(~owner))
smp_yield_cpu(~owner);
- first_diag = 0;
- }
}
}
EXPORT_SYMBOL(arch_spin_lock_wait);
@@ -75,42 +96,36 @@ EXPORT_SYMBOL(arch_spin_lock_wait);
void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags)
{
int cpu = SPINLOCK_LOCKVAL;
- int owner, count, first_diag;
+ int owner, count;
local_irq_restore(flags);
- first_diag = 1;
+
+ /* Pass the virtual CPU to the lock holder if it is not running */
+ owner = arch_load_niai4(&lp->lock);
+ if (owner && arch_vcpu_is_preempted(~owner))
+ smp_yield_cpu(~owner);
+
+ count = spin_retry;
while (1) {
- owner = ACCESS_ONCE(lp->lock);
+ owner = arch_load_niai4(&lp->lock);
/* Try to get the lock if it is free. */
if (!owner) {
local_irq_disable();
- if (__atomic_cmpxchg_bool(&lp->lock, 0, cpu))
+ if (arch_cmpxchg_niai8(&lp->lock, 0, cpu))
return;
local_irq_restore(flags);
continue;
}
- /* Check if the lock owner is running. */
- if (first_diag && arch_vcpu_is_preempted(~owner)) {
- smp_yield_cpu(~owner);
- first_diag = 0;
+ if (count-- >= 0)
continue;
- }
- /* Loop for a while on the lock value. */
count = spin_retry;
- do {
- owner = ACCESS_ONCE(lp->lock);
- } while (owner && count-- > 0);
- if (!owner)
- continue;
/*
* For multiple layers of hypervisors, e.g. z/VM + LPAR
* yield the CPU unconditionally. For LPAR rely on the
* sense running status.
*/
- if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(~owner)) {
+ if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(~owner))
smp_yield_cpu(~owner);
- first_diag = 0;
- }
}
}
EXPORT_SYMBOL(arch_spin_lock_wait_flags);
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index b3bd3f23b8e8..4ea9106417ee 100644
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -15,8 +15,30 @@
#include <asm/mmu_context.h>
#include <asm/facility.h>
+#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
static DEFINE_STATIC_KEY_FALSE(have_mvcos);
+static int __init uaccess_init(void)
+{
+ if (test_facility(27))
+ static_branch_enable(&have_mvcos);
+ return 0;
+}
+early_initcall(uaccess_init);
+
+static inline int copy_with_mvcos(void)
+{
+ if (static_branch_likely(&have_mvcos))
+ return 1;
+ return 0;
+}
+#else
+static inline int copy_with_mvcos(void)
+{
+ return 1;
+}
+#endif
+
static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
unsigned long size)
{
@@ -84,7 +106,7 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
{
- if (static_branch_likely(&have_mvcos))
+ if (copy_with_mvcos())
return copy_from_user_mvcos(to, from, n);
return copy_from_user_mvcp(to, from, n);
}
@@ -157,7 +179,7 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
- if (static_branch_likely(&have_mvcos))
+ if (copy_with_mvcos())
return copy_to_user_mvcos(to, from, n);
return copy_to_user_mvcs(to, from, n);
}
@@ -220,7 +242,7 @@ static inline unsigned long copy_in_user_mvc(void __user *to, const void __user
unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
- if (static_branch_likely(&have_mvcos))
+ if (copy_with_mvcos())
return copy_in_user_mvcos(to, from, n);
return copy_in_user_mvc(to, from, n);
}
@@ -292,7 +314,7 @@ static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
unsigned long __clear_user(void __user *to, unsigned long size)
{
- if (static_branch_likely(&have_mvcos))
+ if (copy_with_mvcos())
return clear_user_mvcos(to, size);
return clear_user_xc(to, size);
}
@@ -349,11 +371,3 @@ long __strncpy_from_user(char *dst, const char __user *src, long size)
return done;
}
EXPORT_SYMBOL(__strncpy_from_user);
-
-static int __init uaccess_init(void)
-{
- if (test_facility(27))
- static_branch_enable(&have_mvcos);
- return 0;
-}
-early_initcall(uaccess_init);
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-23 14:17:19 +0300