> -Original Message-
> From: Matheus Tavares Bernardino
> Sent: Tuesday, April 30, 2024 9:25 AM
> To: qemu-devel@nongnu.org
> Cc: bc...@quicinc.com; sidn...@quicinc.com; a...@rev.ng; a...@rev.ng;
> ltaylorsimp...@gmail.com; richard.hender...@linaro.org; Laurent Vivier
>
> Subject: [PATCH v3] Hexagon: add PC alignment check and exception
>
> The Hexagon Programmer's Reference Manual says that the exception 0x1e
> should be raised upon an unaligned program counter. Let's implement that
> and also add some tests.
>
> Signed-off-by: Matheus Tavares Bernardino
> ---
> v2: https://lore.kernel.org/qemu-
> devel/e559b521d1920f804df10244c8c07564431aeba5.1714419461.git.quic_ma
> thb...@quicinc.com/
>
> Thanks for the comments, Richard and Taylor!
>
> Changed in v3:
> - Removed now unnecessary pkt_raises_exception addition.
> - Added HEX_EXCP_PC_NOT_ALIGNED handling at
> linux-user/hexagon/cpu_loop.c.
> - Merged all tests into a C file that uses signal handler to check
> that the exception was raised.
>
> target/hexagon/cpu.h | 7 ++
> target/hexagon/cpu_bits.h | 4 +
> target/hexagon/macros.h| 3 -
> linux-user/hexagon/cpu_loop.c | 4 +
> target/hexagon/op_helper.c | 9 +--
> tests/tcg/hexagon/unaligned_pc.c | 85 ++
> tests/tcg/hexagon/Makefile.target | 4 +
> tests/tcg/hexagon/unaligned_pc_multi_cof.S | 5 ++
> 8 files changed, 113 insertions(+), 8 deletions(-) create mode 100644
> tests/tcg/hexagon/unaligned_pc.c create mode 100644
> tests/tcg/hexagon/unaligned_pc_multi_cof.S
>
> a/tests/tcg/hexagon/unaligned_pc.c b/tests/tcg/hexagon/unaligned_pc.c
> new file mode 100644
> index 00..1add2d0d99
> --- /dev/null
> +++ b/tests/tcg/hexagon/unaligned_pc.c
> @@ -0,0 +1,85 @@
> +#include
> +#include
> +#include
> +#include
> +
> +/* will be changed in signal handler */ volatile sig_atomic_t
> +completed_tests; static jmp_buf after_test; static int nr_tests;
> +
> +void __attribute__((naked)) test_return(void) {
> +asm volatile(
> +"allocframe(#0x8)\n"
> +"r0 = #0x\n"
> +"framekey = r0\n"
> +"dealloc_return\n"
> +: : : "r0");
Add r29, r30, r31 to clobbers list.
Add framekey to clobbers list (assuming the compiler will take it).
> +}
> +
> +void test_endloop(void)
> +{
> +asm volatile(
> +"loop0(1f, #2)\n"
> +"1: r0 = #0x3\n"
> +"sa0 = r0\n"
> +"{ nop }:endloop0\n"
> +: : : "r0");
> +}
Add sa0, lc0, usr to the clobbers list.
> +
> +void test_multi_cof(void)
> +{
> +asm volatile(
> +"p0 = cmp.eq(r0, r0)\n"
> +"{\n"
> +"if (p0) jump test_multi_cof_unaligned\n"
> +"jump 1f\n"
> +"}\n"
> +"1: nop\n"
> +: : : "p0");
> +}
> +
> +void sigbus_handler(int signum)
> +{
> +/* retore framekey after test_return */
> +asm volatile(
> +"r0 = #0\n"
> +"framekey = r0\n"
> +: : : "r0");
Add framekey to the clobbers list.
> +printf("Test %d complete\n", completed_tests);
> +completed_tests++;
> +siglongjmp(after_test, 1);
> +}
> +
> +void test_done(void)
> +{
> +int err = (completed_tests != nr_tests);
> +puts(err ? "FAIL" : "PASS");
> +exit(err);
> +}
> +
> +typedef void (*test_fn)(void);
> +
> +int main()
> +{
> +test_fn tests[] = { test_return, test_endloop, test_multi_cof,
test_done
> };
> +nr_tests = (sizeof(tests) / sizeof(tests[0])) - 1;
> +
> +struct sigaction sa = {
> +.sa_sigaction = sigbus_handler,
> +.sa_flags = SA_SIGINFO
> +};
> +
> +if (sigaction(SIGBUS, , NULL) < 0) {
> +perror("sigaction");
> +return EXIT_FAILURE;
> +}
> +
> +sigsetjmp(after_test, 1);
> +tests[completed_tests]();
> +
> +/* should never get here */
> +puts("FAIL");
> +return 1;
> +}
> diff --git a/tests/tcg/hexagon/Makefile.target
> b/tests/tcg/hexagon/Makefile.target
> index f839b2c0d5..75139e731c 100644
> --- a/tests/tcg/hexagon/Makefile.target
> +++ b/tests/tcg/hexagon/Makefile.target
> @@ -51,6 +51,7 @@ HEX_TESTS += scatter_gather HEX_TESTS += hvx_misc
> HEX_TESTS += hvx_histogram HEX_TESTS += invalid-slots
> +HEX_TESTS += unaligned_pc
>
> run-and-check-exception = $(call run-test,$2,$3 2>$2.stderr; \
> test $$? -eq 1 && grep -q "exception $(strip $1)" $2.stderr) @@ -
> 108,6 +109,9 @@ preg_alias: preg_alias.c hex_test.h
> read_write_overlap: read_write_overlap.c hex_test.h
> reg_mut: reg_mut.c hex_test.h
>
> +unaligned_pc: unaligned_pc.c unaligned_pc_multi_cof.S
> + $(CC) $(CFLAGS) $(CROSS_CC_GUEST_CFLAGS) -mv73 $^ -o $@
> $(LDFLAGS)
> +
> # This test has to be compiled for the -mv67t target
> usr: usr.c hex_test.h
> $(CC) $(CFLAGS) -mv67t -O2 -Wno-inline-asm -Wno-expansion-to-
> defined $< -o $@ $(LDFLAGS) diff --git
>
