selftests/powerpc: Add checks for transactional GPRs in signal contexts

If a thread receives a signal while transactional the kernel creates a
second context to show the transactional state of the process. This
test loads some known values and waits for a signal and confirms that
the expected values are in the signal context.

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 114 insertions, 0 deletions

diff --git a/tools/testing/selftests/powerpc/tm/tm-signal.S b/tools/testing/selftests/powerpc/tm/tm-signal.S
new file mode 100644
index 000000000000..4e13e8b3a96f
--- /dev/null
+++ b/tools/testing/selftests/powerpc/tm/tm-signal.S
@@ -0,0 +1,114 @@
+/*
+ * Copyright 2015, Cyril Bur, IBM Corp.
+ *
+ * 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 "../basic_asm.h"
+#include "../gpr_asm.h"
+#include "../fpu_asm.h"
+#include "../vmx_asm.h"
+#include "../vsx_asm.h"
+
+/*
+ * Large caveat here being that the caller cannot expect the
+ * signal to always be sent! The hardware can (AND WILL!) abort
+ * the transaction between the tbegin and the tsuspend (however
+ * unlikely it seems or infrequently it actually happens).
+ * You have been warned.
+ */
+/* long tm_signal_self(pid_t pid, long *gprs, double *fps, vector *vms, vector *vss); */
+FUNC_START(tm_signal_self_context_load)
+	PUSH_BASIC_STACK(512)
+	/*
+	 * Don't strictly need to save and restore as it depends on if
+	 * we're going to use them, however this reduces messy logic
+	 */
+	PUSH_VMX(STACK_FRAME_LOCAL(5,0),r8)
+	PUSH_FPU(512)
+	PUSH_NVREGS_BELOW_FPU(512)
+	std r3, STACK_FRAME_PARAM(0)(sp) /* pid */
+	std r4, STACK_FRAME_PARAM(1)(sp) /* gps */
+	std r5, STACK_FRAME_PARAM(2)(sp) /* fps */
+	std r6, STACK_FRAME_PARAM(3)(sp) /* vms */
+	std r7, STACK_FRAME_PARAM(4)(sp) /* vss */
+
+	ld r3, STACK_FRAME_PARAM(1)(sp)
+	cmpdi r3, 0
+	beq skip_gpr_lc
+	bl load_gpr
+skip_gpr_lc:
+	ld r3, STACK_FRAME_PARAM(2)(sp)
+	cmpdi	r3, 0
+	beq	skip_fpu_lc
+	bl load_fpu
+skip_fpu_lc:
+	ld r3, STACK_FRAME_PARAM(3)(sp)
+	cmpdi r3, 0
+	beq	skip_vmx_lc
+	bl load_vmx
+skip_vmx_lc:
+	ld r3, STACK_FRAME_PARAM(4)(sp)
+	cmpdi	r3, 0
+	beq	skip_vsx_lc
+	bl load_vsx
+skip_vsx_lc:
+	/*
+	 * Set r3 (return value) before tbegin. Use the pid as a known
+	 * 'all good' return value, zero is used to indicate a non-doomed
+	 * transaction.
+	 */
+	ld	r3, STACK_FRAME_PARAM(0)(sp)
+	tbegin.
+	beq	1f
+	tsuspend. /* Can't enter a syscall transactionally */
+	ld	r3, STACK_FRAME_PARAM(1)(sp)
+	cmpdi	r3, 0
+	beq skip_gpr_lt
+	/* Get the second half of the array */
+	addi	r3, r3, 8 * 18
+	bl load_gpr
+skip_gpr_lt:
+	ld r3, STACK_FRAME_PARAM(2)(sp)
+	cmpdi	r3, 0
+	beq	skip_fpu_lt
+	/* Get the second half of the array */
+	addi	r3, r3, 8 * 18
+	bl load_fpu
+skip_fpu_lt:
+	ld r3, STACK_FRAME_PARAM(3)(sp)
+	cmpdi r3, 0
+	beq	skip_vmx_lt
+	/* Get the second half of the array */
+	addi	r3, r3, 16 * 12
+	bl load_vmx
+skip_vmx_lt:
+	ld r3, STACK_FRAME_PARAM(4)(sp)
+	cmpdi	r3, 0
+	beq	skip_vsx_lt
+	/* Get the second half of the array */
+	addi	r3, r3, 16 * 12
+	bl load_vsx
+skip_vsx_lt:
+	li	r0, 37 /* sys_kill */
+	ld r3, STACK_FRAME_PARAM(0)(sp) /* pid */
+	li r4, 10 /* SIGUSR1 */
+	sc /* Taking the signal will doom the transaction */
+	tabort. 0
+	tresume. /* Be super sure we abort */
+	/*
+	 * This will cause us to resume doomed transaction and cause
+	 * hardware to cleanup, we'll end up at 1: anything between
+	 * tresume. and 1: shouldn't ever run.
+	 */
+	li r3, 0
+	1:
+	POP_VMX(STACK_FRAME_LOCAL(5,0),r4)
+	POP_FPU(512)
+	POP_NVREGS_BELOW_FPU(512)
+	POP_BASIC_STACK(512)
+	blr
+FUNC_END(tm_signal_self_context_load)