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Message-Id: <1417507013-11948-4-git-send-email-khandual@linux.vnet.ibm.com>
Date: Tue, 2 Dec 2014 13:26:47 +0530
From: Anshuman Khandual <khandual@...ux.vnet.ibm.com>
To: linux-kernel@...r.kernel.org, linuxppc-dev@...abs.org
Cc: peterz@...radead.org, akpm@...ux-foundation.org,
tglx@...utronix.de, james.hogan@...tec.com, avagin@...nvz.org,
Paul.Clothier@...tec.com, palves@...hat.com, oleg@...hat.com,
dhowells@...hat.com, davej@...hat.com, davem@...emloft.net,
mikey@...ling.org, benh@...nel.crashing.org,
sukadev@...ux.vnet.ibm.com, mpe@...erman.id.au,
sam.bobroff@....ibm.com, kirjanov@...il.com,
shuahkh@....samsung.com
Subject: [PATCH V6 3/9] powerpc, ptrace: Enable fpr_(get/set) for transactional memory
This patch enables the fpr_get which gets the running value of all
the FPR registers and the fpr_set which sets the running value of
of all the FPR registers to accommodate in transaction ptrace
interface based requests.
Signed-off-by: Anshuman Khandual <khandual@...ux.vnet.ibm.com>
---
arch/powerpc/kernel/ptrace.c | 110 ++++++++++++++++++++++++++++++++++++++++---
1 file changed, 104 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index f21897b..2de3b2c 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -357,6 +357,36 @@ static int gpr_set(struct task_struct *target, const struct user_regset *regset,
return ret;
}
+
+/**
+ * fpr_get - get FPR registers
+ * @target: The target task.
+ * @regset: The user regset structure.
+ * @pos: The buffer position.
+ * @count: Number of bytes to copy.
+ * @kbuf: Kernel buffer to copy from.
+ * @ubuf: User buffer to copy into.
+ *
+ * When the transaction is active, 'transact_fp' holds the current running
+ * value of all FPR registers and 'fp_state' holds the last checkpointed
+ * value of all FPR registers for the current transaction. When transaction
+ * is not active 'fp_state' holds the current running state of all the FPR
+ * registers. So this function which returns the current running values of
+ * all the FPR registers, needs to know whether any transaction is active
+ * or not. The userspace interface buffer layout is as follows.
+ *
+ * struct data {
+ * u64 fpr[32];
+ * u64 fpscr;
+ * };
+ *
+ * There are two config options CONFIG_VSX and CONFIG_PPC_TRANSACTIONAL_MEM
+ * which determines the final code in this function. All the combinations of
+ * these two config options are possible except the one below as transactional
+ * memory config pulls in CONFIG_VSX automatically.
+ *
+ * !defined(CONFIG_VSX) && defined(CONFIG_PPC_TRANSACTIONAL_MEM)
+ */
static int fpr_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
@@ -367,22 +397,68 @@ static int fpr_get(struct task_struct *target, const struct user_regset *regset,
#endif
flush_fp_to_thread(target);
-#ifdef CONFIG_VSX
+#if defined(CONFIG_VSX) && defined(CONFIG_PPC_TRANSACTIONAL_MEM)
+ /* copy to local buffer then write that out */
+ if (MSR_TM_ACTIVE(target->thread.regs->msr)) {
+ flush_altivec_to_thread(target);
+ flush_tmregs_to_thread(target);
+ for (i = 0; i < 32 ; i++)
+ buf[i] = target->thread.TS_TRANS_FPR(i);
+ buf[32] = target->thread.transact_fp.fpscr;
+ } else {
+ for (i = 0; i < 32 ; i++)
+ buf[i] = target->thread.TS_FPR(i);
+ buf[32] = target->thread.fp_state.fpscr;
+ }
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf, buf, 0, -1);
+#endif
+
+#if defined(CONFIG_VSX) && !defined(CONFIG_PPC_TRANSACTIONAL_MEM)
/* copy to local buffer then write that out */
for (i = 0; i < 32 ; i++)
buf[i] = target->thread.TS_FPR(i);
buf[32] = target->thread.fp_state.fpscr;
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, buf, 0, -1);
+#endif
-#else
+
+#if !defined(CONFIG_VSX) && !defined(CONFIG_PPC_TRANSACTIONAL_MEM)
BUILD_BUG_ON(offsetof(struct thread_fp_state, fpscr) !=
offsetof(struct thread_fp_state, fpr[32][0]));
-
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.fp_state, 0, -1);
#endif
}
+/**
+ * fpr_set - set FPR registers
+ * @target: The target task.
+ * @regset: The user regset structure.
+ * @pos: The buffer position.
+ * @count: Number of bytes to copy.
+ * @kbuf: Kernel buffer to copy into.
+ * @ubuf: User buffer to copy from.
+ *
+ * When the transaction is active, 'transact_fp' holds the current running
+ * value of all FPR registers and 'fp_state' holds the last checkpointed
+ * value of all FPR registers for the current transaction. When transaction
+ * is not active 'fp_state' holds the current running state of all the FPR
+ * registers. So this function which setss the current running values of
+ * all the FPR registers, needs to know whether any transaction is active
+ * or not. The userspace interface buffer layout is as follows.
+ *
+ * struct data {
+ * u64 fpr[32];
+ * u64 fpscr;
+ * };
+ *
+ * There are two config options CONFIG_VSX and CONFIG_PPC_TRANSACTIONAL_MEM
+ * which determines the final code in this function. All the combinations of
+ * these two config options are possible except the one below as transactional
+ * memory config pulls in CONFIG_VSX automatically.
+ *
+ * !defined(CONFIG_VSX) && defined(CONFIG_PPC_TRANSACTIONAL_MEM)
+ */
static int fpr_set(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
@@ -393,7 +469,27 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset,
#endif
flush_fp_to_thread(target);
-#ifdef CONFIG_VSX
+#if defined(CONFIG_VSX) && defined(CONFIG_PPC_TRANSACTIONAL_MEM)
+ /* copy to local buffer then write that out */
+ i = user_regset_copyin(&pos, &count, &kbuf, &ubuf, buf, 0, -1);
+ if (i)
+ return i;
+
+ if (MSR_TM_ACTIVE(target->thread.regs->msr)) {
+ flush_altivec_to_thread(target);
+ flush_tmregs_to_thread(target);
+ for (i = 0; i < 32 ; i++)
+ target->thread.TS_TRANS_FPR(i) = buf[i];
+ target->thread.transact_fp.fpscr = buf[32];
+ } else {
+ for (i = 0; i < 32 ; i++)
+ target->thread.TS_FPR(i) = buf[i];
+ target->thread.fp_state.fpscr = buf[32];
+ }
+ return 0;
+#endif
+
+#if defined(CONFIG_VSX) && !defined(CONFIG_PPC_TRANSACTIONAL_MEM)
/* copy to local buffer then write that out */
i = user_regset_copyin(&pos, &count, &kbuf, &ubuf, buf, 0, -1);
if (i)
@@ -402,12 +498,14 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset,
target->thread.TS_FPR(i) = buf[i];
target->thread.fp_state.fpscr = buf[32];
return 0;
-#else
+#endif
+
+#if !defined(CONFIG_VSX) && !defined(CONFIG_PPC_TRANSACTIONAL_MEM)
BUILD_BUG_ON(offsetof(struct thread_fp_state, fpscr) !=
offsetof(struct thread_fp_state, fpr[32][0]));
-
return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&target->thread.fp_state, 0, -1);
+
#endif
}
--
1.9.3
--
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