diff options
author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-04-14 15:11:26 +0200 |
---|---|---|
committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-05-20 08:58:46 +0200 |
commit | beef560b4cdfafb2211a856e1d722540f5151933 (patch) | |
tree | 7ded8bd3d03266371d68d74d2d96ce8728c2390d /arch/s390/include | |
parent | f4192bf2dc5ae3b24ffb004e771397e737ef01e0 (diff) | |
download | linux-beef560b4cdfafb2211a856e1d722540f5151933.tar.bz2 |
s390/uaccess: simplify control register updates
Always switch to the kernel ASCE in switch_mm. Load the secondary
space ASCE in finish_arch_post_lock_switch after checking that
any pending page table operations have completed. The primary
ASCE is loaded in entry[64].S. With this the update_primary_asce
call can be removed from the switch_to macro and from the start
of switch_mm function. Remove the load_primary argument from
update_user_asce/clear_user_asce, rename update_user_asce to
set_user_asce and rename update_primary_asce to load_kernel_asce.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include')
-rw-r--r-- | arch/s390/include/asm/futex.h | 4 | ||||
-rw-r--r-- | arch/s390/include/asm/mmu_context.h | 43 | ||||
-rw-r--r-- | arch/s390/include/asm/switch_to.h | 1 | ||||
-rw-r--r-- | arch/s390/include/asm/thread_info.h | 4 |
4 files changed, 20 insertions, 32 deletions
diff --git a/arch/s390/include/asm/futex.h b/arch/s390/include/asm/futex.h index 69cf5b5eddc9..a4811aa0304d 100644 --- a/arch/s390/include/asm/futex.h +++ b/arch/s390/include/asm/futex.h @@ -29,7 +29,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) int cmparg = (encoded_op << 20) >> 20; int oldval = 0, newval, ret; - update_primary_asce(current); + load_kernel_asce(); if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; @@ -79,7 +79,7 @@ static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, { int ret; - update_primary_asce(current); + load_kernel_asce(); asm volatile( " sacf 256\n" "0: cs %1,%4,0(%5)\n" diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h index 71be346d0e3c..93ec0c8e4c83 100644 --- a/arch/s390/include/asm/mmu_context.h +++ b/arch/s390/include/asm/mmu_context.h @@ -30,33 +30,31 @@ static inline int init_new_context(struct task_struct *tsk, #define destroy_context(mm) do { } while (0) -static inline void update_user_asce(struct mm_struct *mm, int load_primary) +static inline void set_user_asce(struct mm_struct *mm) { pgd_t *pgd = mm->pgd; S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd); - if (load_primary) - __ctl_load(S390_lowcore.user_asce, 1, 1); set_fs(current->thread.mm_segment); + set_thread_flag(TIF_ASCE); } -static inline void clear_user_asce(struct mm_struct *mm, int load_primary) +static inline void clear_user_asce(void) { S390_lowcore.user_asce = S390_lowcore.kernel_asce; - if (load_primary) - __ctl_load(S390_lowcore.user_asce, 1, 1); + __ctl_load(S390_lowcore.user_asce, 1, 1); __ctl_load(S390_lowcore.user_asce, 7, 7); } -static inline void update_primary_asce(struct task_struct *tsk) +static inline void load_kernel_asce(void) { unsigned long asce; __ctl_store(asce, 1, 1); if (asce != S390_lowcore.kernel_asce) __ctl_load(S390_lowcore.kernel_asce, 1, 1); - set_tsk_thread_flag(tsk, TIF_ASCE); + set_thread_flag(TIF_ASCE); } static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, @@ -64,25 +62,17 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, { int cpu = smp_processor_id(); - update_primary_asce(tsk); if (prev == next) return; if (MACHINE_HAS_TLB_LC) cpumask_set_cpu(cpu, &next->context.cpu_attach_mask); - if (atomic_inc_return(&next->context.attach_count) >> 16) { - /* Delay update_user_asce until all TLB flushes are done. */ - set_tsk_thread_flag(tsk, TIF_TLB_WAIT); - /* Clear old ASCE by loading the kernel ASCE. */ - clear_user_asce(next, 0); - } else { - cpumask_set_cpu(cpu, mm_cpumask(next)); - update_user_asce(next, 0); - if (next->context.flush_mm) - /* Flush pending TLBs */ - __tlb_flush_mm(next); - } + /* Clear old ASCE by loading the kernel ASCE. */ + __ctl_load(S390_lowcore.kernel_asce, 1, 1); + __ctl_load(S390_lowcore.kernel_asce, 7, 7); + /* Delay loading of the new ASCE to control registers CR1 & CR7 */ + set_thread_flag(TIF_ASCE); + atomic_inc(&next->context.attach_count); atomic_dec(&prev->context.attach_count); - WARN_ON(atomic_read(&prev->context.attach_count) < 0); if (MACHINE_HAS_TLB_LC) cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask); } @@ -93,15 +83,14 @@ static inline void finish_arch_post_lock_switch(void) struct task_struct *tsk = current; struct mm_struct *mm = tsk->mm; - if (!test_tsk_thread_flag(tsk, TIF_TLB_WAIT)) + if (!mm) return; preempt_disable(); - clear_tsk_thread_flag(tsk, TIF_TLB_WAIT); while (atomic_read(&mm->context.attach_count) >> 16) cpu_relax(); cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm)); - update_user_asce(mm, 0); + set_user_asce(mm); if (mm->context.flush_mm) __tlb_flush_mm(mm); preempt_enable(); @@ -113,7 +102,9 @@ static inline void finish_arch_post_lock_switch(void) static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next) { - switch_mm(prev, next, current); + switch_mm(prev, next, current); + cpumask_set_cpu(smp_processor_id(), mm_cpumask(next)); + set_user_asce(next); } static inline void arch_dup_mmap(struct mm_struct *oldmm, diff --git a/arch/s390/include/asm/switch_to.h b/arch/s390/include/asm/switch_to.h index e759181357fc..29c81f82705e 100644 --- a/arch/s390/include/asm/switch_to.h +++ b/arch/s390/include/asm/switch_to.h @@ -132,7 +132,6 @@ static inline void restore_access_regs(unsigned int *acrs) update_cr_regs(next); \ } \ prev = __switch_to(prev,next); \ - update_primary_asce(current); \ } while (0) #define finish_arch_switch(prev) do { \ diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h index 50630e6a35de..f3e5cad93b26 100644 --- a/arch/s390/include/asm/thread_info.h +++ b/arch/s390/include/asm/thread_info.h @@ -81,8 +81,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ #define TIF_SIGPENDING 2 /* signal pending */ #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ -#define TIF_TLB_WAIT 4 /* wait for TLB flush completion */ -#define TIF_ASCE 5 /* primary asce needs fixup / uaccess */ +#define TIF_ASCE 5 /* user asce needs fixup / uaccess */ #define TIF_PER_TRAP 6 /* deliver sigtrap on return to user */ #define TIF_MCCK_PENDING 7 /* machine check handling is pending */ #define TIF_SYSCALL_TRACE 8 /* syscall trace active */ @@ -99,7 +98,6 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) #define _TIF_SIGPENDING (1<<TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED) -#define _TIF_TLB_WAIT (1<<TIF_TLB_WAIT) #define _TIF_ASCE (1<<TIF_ASCE) #define _TIF_PER_TRAP (1<<TIF_PER_TRAP) #define _TIF_MCCK_PENDING (1<<TIF_MCCK_PENDING) |