The COMMPAGE are a number of kernel provided user-space routines for
32 bit ARM systems. Add a basic series of smoke tests to ensure it is
working as it should.
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
---
tests/tcg/arm/commpage.c | 61 +++++++++++++++++++++++++++++++++++
tests/tcg/arm/Makefile.target | 2 ++
2 files changed, 63 insertions(+)
create mode 100644 tests/tcg/arm/commpage.c
diff --git a/tests/tcg/arm/commpage.c b/tests/tcg/arm/commpage.c
new file mode 100644
index 00000000000..c76e70cb8bd
--- /dev/null
+++ b/tests/tcg/arm/commpage.c
@@ -0,0 +1,61 @@
+/*
+ * Verify the COMMPAGE emulation
+ *
+ * The ARM commpage is a set of user space helper functions provided
+ * by the kernel in an effort to ease portability of user space code
+ * between different CPUs with potentially different capabilities. It
+ * is a 32 bit invention and similar to the vdso segment in many ways.
+ *
+ * The ABI is documented in the Linux kernel:
+ * Documentation/arm/kernel_userspace_helpers.rst
+ *
+ * Copyright (c) 2020 Linaro Ltd
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+
+#define ARM_COMMPAGE (0xffff0f00u)
+#define ARM_KUSER_VERSION (*(int32_t *)(ARM_COMMPAGE + 0xfc))
+typedef void * (get_tls_fn)(void);
+#define ARM_KUSER_GET_TLS (*(get_tls_fn *)(ARM_COMMPAGE + 0xe0))
+typedef int (cmpxchg_fn)(int oldval, int newval, volatile int *ptr);
+#define ARM_KUSER_CMPXCHG (*(cmpxchg_fn *)(ARM_COMMPAGE + 0xc0))
+typedef void (dmb_fn)(void);
+#define ARM_KUSER_DMB (*(dmb_fn *)(ARM_COMMPAGE + 0xa0))
+typedef int (cmpxchg64_fn)(const int64_t *oldval,
+ const int64_t *newval,
+ volatile int64_t *ptr);
+#define ARM_KUSER_CMPXCHG64 (*(cmpxchg64_fn *)(ARM_COMMPAGE + 0x60))
+
+#define fail_unless(x) \
+ do { \
+ if (!(x)) { \
+ fprintf(stderr, "FAILED at %s:%d\n", __FILE__, __LINE__); \
+ exit(EXIT_FAILURE); \
+ } \
+ } while (0)
+
+
+int main(int argc, char *argv[argc])
+{
+ void *kuser_tls;
+ int val = 1;
+ const int64_t oldval = 1, newval = 2;
+ int64_t val64 = 1;
+
+ fail_unless(ARM_KUSER_VERSION == 0x5);
+ kuser_tls = ARM_KUSER_GET_TLS();
+ printf("TLS = %p\n", kuser_tls);
+ fail_unless(kuser_tls != 0);
+ fail_unless(ARM_KUSER_CMPXCHG(1, 2, &val) == 0);
+ printf("val = %d\n", val);
+ /* this is a crash test, not checking an actual barrier occurs */
+ ARM_KUSER_DMB();
+ fail_unless(ARM_KUSER_CMPXCHG64(&oldval, &newval, &val64) == 0);
+ printf("val64 = %lld\n", val64);
+ return 0;
+}
diff --git a/tests/tcg/arm/Makefile.target b/tests/tcg/arm/Makefile.target
index 11c39c601ea..3da09a38be7 100644
--- a/tests/tcg/arm/Makefile.target
+++ b/tests/tcg/arm/Makefile.target
@@ -68,6 +68,8 @@ run-semiconsole-arm: semiconsole-arm
run-plugin-semiconsole-arm-with-%:
$(call skip-test, $<, "MANUAL ONLY")
+ARM_TESTS += commpage
+
TESTS += $(ARM_TESTS)
# On ARM Linux only supports 4k pages
--
2.20.1
