@@ -260,6 +260,7 @@ struct thread_struct {
unsigned long sier2;
unsigned long sier3;
unsigned long hashkeyr;
+ unsigned long dexcr;
#endif
};
@@ -1185,6 +1185,9 @@ static inline void save_sprs(struct thread_struct *t)
if (cpu_has_feature(CPU_FTR_DEXCR_NPHIE))
t->hashkeyr = mfspr(SPRN_HASHKEYR);
+
+ if (cpu_has_feature(CPU_FTR_ARCH_31))
+ t->dexcr = mfspr(SPRN_DEXCR);
#endif
}
@@ -1267,6 +1270,10 @@ static inline void restore_sprs(struct thread_struct *old_thread,
if (cpu_has_feature(CPU_FTR_DEXCR_NPHIE) &&
old_thread->hashkeyr != new_thread->hashkeyr)
mtspr(SPRN_HASHKEYR, new_thread->hashkeyr);
+
+ if (cpu_has_feature(CPU_FTR_ARCH_31) &&
+ old_thread->dexcr != new_thread->dexcr)
+ mtspr(SPRN_DEXCR, new_thread->dexcr);
#endif
}
@@ -1878,6 +1885,9 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
#ifdef CONFIG_PPC_BOOK3S_64
if (cpu_has_feature(CPU_FTR_DEXCR_NPHIE))
p->thread.hashkeyr = current->thread.hashkeyr;
+
+ if (cpu_has_feature(CPU_FTR_ARCH_31))
+ p->thread.dexcr = mfspr(SPRN_DEXCR);
#endif
return 0;
}
@@ -469,12 +469,7 @@ static int dexcr_get(struct task_struct *target, const struct user_regset *regse
if (!cpu_has_feature(CPU_FTR_ARCH_31))
return -ENODEV;
- /*
- * The DEXCR is currently static across all CPUs, so we don't
- * store the target's value anywhere, but the static value
- * will also be correct.
- */
- membuf_store(&to, (u64)lower_32_bits(DEXCR_INIT));
+ membuf_store(&to, (u64)lower_32_bits(target->thread.dexcr));
/*
* Technically the HDEXCR is per-cpu, but a hypervisor can't reasonably
Add capability to make the DEXCR act as a per-process SPR. We do not yet have an interface for changing the values per task. We also expect the kernel to use a single DEXCR value across all tasks while in privileged state, so there is no need to synchronize after changing it (the userspace aspects will synchronize upon returning to userspace). Signed-off-by: Benjamin Gray <bgray@linux.ibm.com> --- arch/powerpc/include/asm/processor.h | 1 + arch/powerpc/kernel/process.c | 10 ++++++++++ arch/powerpc/kernel/ptrace/ptrace-view.c | 7 +------ 3 files changed, 12 insertions(+), 6 deletions(-)