[V5 4/7] powerpc, ptrace: Enable vr_(get/set) for transactional memory

From: Anshuman Khandual
Date: Tue Nov 25 2014 - 03:06:16 EST


This patch enables the vr_get which gets the running value of all
the VMX registers and the vr_set which sets the running value of
of all the VMX registers to accommodate in transaction ptrace
interface based requests.

Signed-off-by: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/ptrace.c | 94 ++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 91 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index fd36b32..2bbbd10 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -523,10 +523,30 @@ static int vr_active(struct task_struct *target,
return target->thread.used_vr ? regset->n : 0;
}

+/*
+ * vr_get
+ *
+ * When the transaction is active, 'transact_vr' holds the current running
+ * value of all the VMX registers and 'vr_state' holds the last checkpointed
+ * value of all the VMX registers for the current transaction to fall back
+ * on in case it aborts. When transaction is not active 'vr_state' holds
+ * the current running state of all the VMX registers. So this function which
+ * gets the current running values of all the VMX registers, needs to know
+ * whether any transaction is active or not.
+ *
+ * Userspace interface buffer layout:
+ *
+ * struct data {
+ * vector128 vr[32];
+ * vector128 vscr;
+ * vector128 vrsave;
+ * };
+ */
static int vr_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
+ struct thread_vr_state *addr;
int ret;

flush_altivec_to_thread(target);
@@ -534,8 +554,19 @@ static int vr_get(struct task_struct *target, const struct user_regset *regset,
BUILD_BUG_ON(offsetof(struct thread_vr_state, vscr) !=
offsetof(struct thread_vr_state, vr[32]));

+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ if (MSR_TM_ACTIVE(target->thread.regs->msr)) {
+ flush_fp_to_thread(target);
+ flush_tmregs_to_thread(target);
+ addr = &target->thread.transact_vr;
+ } else {
+ addr = &target->thread.vr_state;
+ }
+#else
+ addr = &target->thread.vr_state;
+#endif
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
- &target->thread.vr_state, 0,
+ addr, 0,
33 * sizeof(vector128));
if (!ret) {
/*
@@ -546,7 +577,16 @@ static int vr_get(struct task_struct *target, const struct user_regset *regset,
u32 word;
} vrsave;
memset(&vrsave, 0, sizeof(vrsave));
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ if (MSR_TM_ACTIVE(target->thread.regs->msr))
+ vrsave.word = target->thread.transact_vrsave;
+ else
+ vrsave.word = target->thread.vrsave;
+#else
vrsave.word = target->thread.vrsave;
+#endif
+
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &vrsave,
33 * sizeof(vector128), -1);
}
@@ -554,10 +594,30 @@ static int vr_get(struct task_struct *target, const struct user_regset *regset,
return ret;
}

+/*
+ * vr_set
+ *
+ * When the transaction is active, 'transact_vr' holds the current running
+ * value of all the VMX registers and 'vr_state' holds the last checkpointed
+ * value of all the VMX registers for the current transaction to fall back
+ * on in case it aborts. When transaction is not active 'vr_state' holds
+ * the current running state of all the VMX registers. So this function which
+ * sets the current running values of all the VMX registers, needs to know
+ * whether any transaction is active or not.
+ *
+ * Userspace interface buffer layout:
+ *
+ * struct data {
+ * vector128 vr[32];
+ * vector128 vscr;
+ * vector128 vrsave;
+ * };
+ */
static int vr_set(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
+ struct thread_vr_state *addr;
int ret;

flush_altivec_to_thread(target);
@@ -565,8 +625,19 @@ static int vr_set(struct task_struct *target, const struct user_regset *regset,
BUILD_BUG_ON(offsetof(struct thread_vr_state, vscr) !=
offsetof(struct thread_vr_state, vr[32]));

+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ if (MSR_TM_ACTIVE(target->thread.regs->msr)) {
+ flush_fp_to_thread(target);
+ flush_tmregs_to_thread(target);
+ addr = &target->thread.transact_vr;
+ } else {
+ addr = &target->thread.vr_state;
+ }
+#else
+ addr = &target->thread.vr_state;
+#endif
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
- &target->thread.vr_state, 0,
+ addr, 0,
33 * sizeof(vector128));
if (!ret && count > 0) {
/*
@@ -577,11 +648,28 @@ static int vr_set(struct task_struct *target, const struct user_regset *regset,
u32 word;
} vrsave;
memset(&vrsave, 0, sizeof(vrsave));
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ if (MSR_TM_ACTIVE(target->thread.regs->msr))
+ vrsave.word = target->thread.transact_vrsave;
+ else
+ vrsave.word = target->thread.vrsave;
+#else
vrsave.word = target->thread.vrsave;
+#endif
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &vrsave,
33 * sizeof(vector128), -1);
- if (!ret)
+ if (!ret) {
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ if (MSR_TM_ACTIVE(target->thread.regs->msr))
+ target->thread.transact_vrsave = vrsave.word;
+ else
+ target->thread.vrsave = vrsave.word;
+#else
target->thread.vrsave = vrsave.word;
+#endif
+ }
}

return ret;
--
1.9.3

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