selftests/powerpc: Add ptrace tests for TAR, PPR, DSCR in suspended TM

This patch adds ptrace interface test for TAR, PPR, DSCR
registers inside suspended TM context.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

tools/testing/selftests/powerpc/ptrace/.gitignore

@@ -3,3 +3,4 @@ ptrace-tm-gpr
 ptrace-tm-spd-gpr
 ptrace-tar
 ptrace-tm-tar
+ptrace-tm-spd-tar

tools/testing/selftests/powerpc/ptrace/Makefile

 TEST_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
-              ptrace-tar ptrace-tm-tar
+              ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar
 
 include ../../lib.mk
 

tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c

+/*
+ * Ptrace test for TAR, PPR, DSCR registers in the TM Suspend context
+ *
+ * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include "ptrace.h"
+#include "tm.h"
+#include "ptrace-tar.h"
+
+int shm_id;
+int *cptr, *pptr;
+
+__attribute__((used)) void wait_parent(void)
+{
+	cptr[2] = 1;
+	while (!cptr[1])
+		asm volatile("" : : : "memory");
+}
+
+void tm_spd_tar(void)
+{
+	unsigned long result, texasr;
+	unsigned long regs[3];
+	int ret;
+
+	cptr = (int *)shmat(shm_id, NULL, 0);
+
+trans:
+	cptr[2] = 0;
+	asm __volatile__(
+		"li	4, %[tar_1];"
+		"mtspr %[sprn_tar],  4;"	/* TAR_1 */
+		"li	4, %[dscr_1];"
+		"mtspr %[sprn_dscr], 4;"	/* DSCR_1 */
+		"or     31,31,31;"		/* PPR_1*/
+
+		"1: ;"
+		"tbegin.;"
+		"beq 2f;"
+
+		"li	4, %[tar_2];"
+		"mtspr %[sprn_tar],  4;"	/* TAR_2 */
+		"li	4, %[dscr_2];"
+		"mtspr %[sprn_dscr], 4;"	/* DSCR_2 */
+		"or     1,1,1;"			/* PPR_2 */
+
+		"tsuspend.;"
+		"li	4, %[tar_3];"
+		"mtspr %[sprn_tar],  4;"	/* TAR_3 */
+		"li	4, %[dscr_3];"
+		"mtspr %[sprn_dscr], 4;"	/* DSCR_3 */
+		"or     6,6,6;"			/* PPR_3 */
+		"bl wait_parent;"
+		"tresume.;"
+
+		"tend.;"
+		"li 0, 0;"
+		"ori %[res], 0, 0;"
+		"b 3f;"
+
+		/* Transaction abort handler */
+		"2: ;"
+		"li 0, 1;"
+		"ori %[res], 0, 0;"
+		"mfspr %[texasr], %[sprn_texasr];"
+
+		"3: ;"
+
+		: [res] "=r" (result), [texasr] "=r" (texasr)
+		: [val] "r" (cptr[1]), [sprn_dscr]"i"(SPRN_DSCR),
+		[sprn_tar]"i"(SPRN_TAR), [sprn_ppr]"i"(SPRN_PPR),
+		[sprn_texasr]"i"(SPRN_TEXASR), [tar_1]"i"(TAR_1),
+		[dscr_1]"i"(DSCR_1), [tar_2]"i"(TAR_2), [dscr_2]"i"(DSCR_2),
+		[tar_3]"i"(TAR_3), [dscr_3]"i"(DSCR_3)
+		: "memory", "r0", "r1", "r3", "r4", "r5", "r6"
+		);
+
+	/* TM failed, analyse */
+	if (result) {
+		if (!cptr[0])
+			goto trans;
+
+		regs[0] = mfspr(SPRN_TAR);
+		regs[1] = mfspr(SPRN_PPR);
+		regs[2] = mfspr(SPRN_DSCR);
+
+		shmdt(&cptr);
+		printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
+				user_read, regs[0], regs[1], regs[2]);
+
+		ret = validate_tar_registers(regs, TAR_4, PPR_4, DSCR_4);
+		if (ret)
+			exit(1);
+		exit(0);
+	}
+	shmdt(&cptr);
+	exit(1);
+}
+
+int trace_tm_spd_tar(pid_t child)
+{
+	unsigned long regs[3];
+
+	FAIL_IF(start_trace(child));
+	FAIL_IF(show_tar_registers(child, regs));
+	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
+			ptrace_read_running, regs[0], regs[1], regs[2]);
+
+	FAIL_IF(validate_tar_registers(regs, TAR_3, PPR_3, DSCR_3));
+	FAIL_IF(show_tm_checkpointed_state(child, regs));
+	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
+			ptrace_read_ckpt, regs[0], regs[1], regs[2]);
+
+	FAIL_IF(validate_tar_registers(regs, TAR_1, PPR_1, DSCR_1));
+	FAIL_IF(write_ckpt_tar_registers(child, TAR_4, PPR_4, DSCR_4));
+	printf("%-30s TAR: %u PPR: %lx DSCR: %u\n",
+			ptrace_write_ckpt, TAR_4, PPR_4, DSCR_4);
+
+	pptr[0] = 1;
+	pptr[1] = 1;
+	FAIL_IF(stop_trace(child));
+	return TEST_PASS;
+}
+
+int ptrace_tm_spd_tar(void)
+{
+	pid_t pid;
+	int ret, status;
+
+	SKIP_IF(!have_htm());
+	shm_id = shmget(IPC_PRIVATE, sizeof(int) * 3, 0777|IPC_CREAT);
+	pid = fork();
+	if (pid == 0)
+		tm_spd_tar();
+
+	pptr = (int *)shmat(shm_id, NULL, 0);
+	pptr[0] = 0;
+	pptr[1] = 0;
+
+	if (pid) {
+		while (!pptr[2])
+			asm volatile("" : : : "memory");
+		ret = trace_tm_spd_tar(pid);
+		if (ret) {
+			kill(pid, SIGTERM);
+			shmdt(&pptr);
+			shmctl(shm_id, IPC_RMID, NULL);
+			return TEST_FAIL;
+		}
+
+		shmdt(&pptr);
+
+		ret = wait(&status);
+		shmctl(shm_id, IPC_RMID, NULL);
+		if (ret != pid) {
+			printf("Child's exit status not captured\n");
+			return TEST_FAIL;
+		}
+
+		return (WIFEXITED(status) && WEXITSTATUS(status)) ? TEST_FAIL :
+			TEST_PASS;
+	}
+	return TEST_PASS;
+}
+
+int main(int argc, char *argv[])
+{
+	return test_harness(ptrace_tm_spd_tar, "ptrace_tm_spd_tar");
+}