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[PATCH v12 09/30] powerpc/ptrace: Enable support for NT_PPC_CVMX

From wei.guo.simon@gmail.com
Newsgroups linux.kernel
Subject [PATCH v12 09/30] powerpc/ptrace: Enable support for NT_PPC_CVMX
Date 2016-07-27 11:30 +0200
Message-ID <rZtk7-5Wg-63@gated-at.bofh.it> (permalink)
References <rZtk6-5Wg-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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From: Anshuman Khandual <khandual@linux.vnet.ibm.com>

This patch enables support for TM checkpointed VMX register
set ELF core note NT_PPC_CVMX based ptrace requests through
PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved
through adding a register set REGSET_CVMX in powerpc
corresponding to the ELF core note section added. It
implements the get, set and active functions for this new
register set added.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Cyril Bur <cyrilbur@gmail.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Simon Guo <wei.guo.simon@gmail.com>
Cc: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Rashmica Gupta <rashmicy@gmail.com>
Cc: Khem Raj <raj.khem@gmail.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Cc: Chris Smart <chris@distroguy.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
---
 arch/powerpc/include/uapi/asm/elf.h |   1 +
 arch/powerpc/kernel/ptrace.c        | 158 ++++++++++++++++++++++++++++++++++++
 2 files changed, 159 insertions(+)

diff --git a/arch/powerpc/include/uapi/asm/elf.h b/arch/powerpc/include/uapi/asm/elf.h
index c2d21d1..ecb4e84 100644
--- a/arch/powerpc/include/uapi/asm/elf.h
+++ b/arch/powerpc/include/uapi/asm/elf.h
@@ -91,6 +91,7 @@
 
 #define ELF_NGREG	48	/* includes nip, msr, lr, etc. */
 #define ELF_NFPREG	33	/* includes fpscr */
+#define ELF_NVMX	34	/* includes all vector registers */
 
 typedef unsigned long elf_greg_t64;
 typedef elf_greg_t64 elf_gregset_t64[ELF_NGREG];
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index cd10022..836a4b4 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -64,6 +64,8 @@ struct pt_regs_offset {
 	{.name = STR(gpr##num), .offset = offsetof(struct pt_regs, gpr[num])}
 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 
+#define TVSO(f)	(offsetof(struct thread_vr_state, f))
+
 static const struct pt_regs_offset regoffset_table[] = {
 	GPR_OFFSET_NAME(0),
 	GPR_OFFSET_NAME(1),
@@ -1147,6 +1149,151 @@ static int tm_cfpr_set(struct task_struct *target,
 	target->thread.fp_state.fpscr = buf[32];
 	return 0;
 }
+
+/**
+ * tm_cvmx_active - get active number of registers in CVMX
+ * @target:	The target task.
+ * @regset:	The user regset structure.
+ *
+ * This function checks for the active number of available
+ * regisers in checkpointed VMX category.
+ */
+static int tm_cvmx_active(struct task_struct *target,
+				const struct user_regset *regset)
+{
+	if (!cpu_has_feature(CPU_FTR_TM))
+		return -ENODEV;
+
+	if (!MSR_TM_ACTIVE(target->thread.regs->msr))
+		return 0;
+
+	return regset->n;
+}
+
+/**
+ * tm_cvmx_get - get CMVX 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.
+ *
+ * This function gets in transaction checkpointed VMX registers.
+ *
+ * When the transaction is active 'vr_state' and 'vr_save' hold
+ * the checkpointed values for the current transaction to fall
+ * back on if it aborts in between. The userspace interface buffer
+ * layout is as follows.
+ *
+ * struct data {
+ *	vector128	vr[32];
+ *	vector128	vscr;
+ *	vector128	vrsave;
+ *};
+ */
+static int tm_cvmx_get(struct task_struct *target,
+			const struct user_regset *regset,
+			unsigned int pos, unsigned int count,
+			void *kbuf, void __user *ubuf)
+{
+	int ret;
+
+	BUILD_BUG_ON(TVSO(vscr) != TVSO(vr[32]));
+
+	if (!cpu_has_feature(CPU_FTR_TM))
+		return -ENODEV;
+
+	if (!MSR_TM_ACTIVE(target->thread.regs->msr))
+		return -ENODATA;
+
+	/* Flush the state */
+	flush_fp_to_thread(target);
+	flush_altivec_to_thread(target);
+	flush_tmregs_to_thread(target);
+
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+					&target->thread.vr_state, 0,
+					33 * sizeof(vector128));
+	if (!ret) {
+		/*
+		 * Copy out only the low-order word of vrsave.
+		 */
+		union {
+			elf_vrreg_t reg;
+			u32 word;
+		} vrsave;
+		memset(&vrsave, 0, sizeof(vrsave));
+		vrsave.word = target->thread.vrsave;
+		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &vrsave,
+						33 * sizeof(vector128), -1);
+	}
+
+	return ret;
+}
+
+/**
+ * tm_cvmx_set - set CMVX 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.
+ *
+ * This function sets in transaction checkpointed VMX registers.
+ *
+ * When the transaction is active 'vr_state' and 'vr_save' hold
+ * the checkpointed values for the current transaction to fall
+ * back on if it aborts in between. The userspace interface buffer
+ * layout is as follows.
+ *
+ * struct data {
+ *	vector128	vr[32];
+ *	vector128	vscr;
+ *	vector128	vrsave;
+ *};
+ */
+static int tm_cvmx_set(struct task_struct *target,
+			const struct user_regset *regset,
+			unsigned int pos, unsigned int count,
+			const void *kbuf, const void __user *ubuf)
+{
+	int ret;
+
+	BUILD_BUG_ON(TVSO(vscr) != TVSO(vr[32]));
+
+	if (!cpu_has_feature(CPU_FTR_TM))
+		return -ENODEV;
+
+	if (!MSR_TM_ACTIVE(target->thread.regs->msr))
+		return -ENODATA;
+
+	flush_fp_to_thread(target);
+	flush_altivec_to_thread(target);
+	flush_tmregs_to_thread(target);
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+					&target->thread.vr_state, 0,
+					33 * sizeof(vector128));
+	if (!ret && count > 0) {
+		/*
+		 * We use only the low-order word of vrsave.
+		 */
+		union {
+			elf_vrreg_t reg;
+			u32 word;
+		} vrsave;
+		memset(&vrsave, 0, sizeof(vrsave));
+		vrsave.word = target->thread.vrsave;
+		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &vrsave,
+						33 * sizeof(vector128), -1);
+		if (!ret)
+			target->thread.vrsave = vrsave.word;
+	}
+
+	return ret;
+}
 #endif
 
 /*
@@ -1167,6 +1314,7 @@ enum powerpc_regset {
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	REGSET_TM_CGPR,		/* TM checkpointed GPR registers */
 	REGSET_TM_CFPR,		/* TM checkpointed FPR registers */
+	REGSET_TM_CVMX,		/* TM checkpointed VMX registers */
 #endif
 };
 
@@ -1213,6 +1361,11 @@ static const struct user_regset native_regsets[] = {
 		.size = sizeof(double), .align = sizeof(double),
 		.active = tm_cfpr_active, .get = tm_cfpr_get, .set = tm_cfpr_set
 	},
+	[REGSET_TM_CVMX] = {
+		.core_note_type = NT_PPC_TM_CVMX, .n = ELF_NVMX,
+		.size = sizeof(vector128), .align = sizeof(vector128),
+		.active = tm_cvmx_active, .get = tm_cvmx_get, .set = tm_cvmx_set
+	},
 #endif
 };
 
@@ -1450,6 +1603,11 @@ static const struct user_regset compat_regsets[] = {
 		.size = sizeof(double), .align = sizeof(double),
 		.active = tm_cfpr_active, .get = tm_cfpr_get, .set = tm_cfpr_set
 	},
+	[REGSET_TM_CVMX] = {
+		.core_note_type = NT_PPC_TM_CVMX, .n = ELF_NVMX,
+		.size = sizeof(vector128), .align = sizeof(vector128),
+		.active = tm_cvmx_active, .get = tm_cvmx_get, .set = tm_cvmx_set
+	},
 #endif
 };
 
-- 
1.8.3.1

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Thread

[PATCH v12 00/30] Add new powerpc specific ELF core notes wei.guo.simon@gmail.com - 2016-07-27 11:30 +0200
  [PATCH v12 09/30] powerpc/ptrace: Enable support for NT_PPC_CVMX wei.guo.simon@gmail.com - 2016-07-27 11:30 +0200
  [PATCH v12 10/30] powerpc/ptrace: Enable support for NT_PPC_CVSX wei.guo.simon@gmail.com - 2016-07-27 11:30 +0200
  [PATCH v12 19/30] selftests/powerpc: Add ptrace tests for GPR/FPR registers wei.guo.simon@gmail.com - 2016-07-27 11:30 +0200
  [PATCH v12 16/30] selftests/powerpc: Add more SPR numbers, TM & VMX instructions to 'reg.h' wei.guo.simon@gmail.com - 2016-07-27 11:30 +0200
  [PATCH v12 27/30] selftests/powerpc: Add ptrace tests for VSX, VMX registers in suspended TM wei.guo.simon@gmail.com - 2016-07-27 11:40 +0200
  [PATCH v12 22/30] selftests/powerpc: Add ptrace tests for TAR, PPR, DSCR registers wei.guo.simon@gmail.com - 2016-07-27 11:40 +0200
  [PATCH v12 26/30] selftests/powerpc: Add ptrace tests for VSX, VMX registers in TM wei.guo.simon@gmail.com - 2016-07-27 11:40 +0200
  [PATCH v12 03/30] powerpc/ptrace: Enable in transaction NT_PRFPREG ptrace requests wei.guo.simon@gmail.com - 2016-07-27 11:40 +0200
  [PATCH v12 30/30] selftests/powerpc: Fix a build issue wei.guo.simon@gmail.com - 2016-07-27 11:40 +0200
  [PATCH v12 07/30] powerpc/ptrace: Enable support for NT_PPC_CGPR wei.guo.simon@gmail.com - 2016-07-27 11:40 +0200
  [PATCH v12 29/30] selftests/powerpc: Add .gitignore file for ptrace executables wei.guo.simon@gmail.com - 2016-07-27 11:40 +0200
  [PATCH v12 18/30] selftests/powerpc: Add ptrace tests for EBB wei.guo.simon@gmail.com - 2016-07-27 11:40 +0200
  [PATCH v12 28/30] selftests/powerpc: Add ptrace tests for TM SPR registers wei.guo.simon@gmail.com - 2016-07-27 11:40 +0200
  [PATCH v12 17/30] selftests/powerpc: Use the new SPRN_DSCR_PRIV definiton wei.guo.simon@gmail.com - 2016-07-27 11:40 +0200
  [PATCH v12 25/30] selftests/powerpc: Add ptrace tests for VSX, VMX registers wei.guo.simon@gmail.com - 2016-07-27 11:40 +0200

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