Verify that we have all the instruction extensions that we generate.
Future patches can tailor code generation to the set of instructions
that are present.
Signed-off-by: Richard Henderson <r...@twiddle.net>
---
tcg/s390/tcg-target.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 113 insertions(+), 0 deletions(-)
diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
index 3944cb1..d99bb5c 100644
--- a/tcg/s390/tcg-target.c
+++ b/tcg/s390/tcg-target.c
@@ -229,6 +229,17 @@ static void *qemu_st_helpers[4] = {
static uint8_t *tb_ret_addr;
+/* A list of relevant facilities used by this translator. Some of these
+ are required for proper operation, and these are checked at startup. */
+
+#define FACILITY_ZARCH (1ULL << (63 - 1))
+#define FACILITY_ZARCH_ACTIVE (1ULL << (63 - 2))
+#define FACILITY_LONG_DISP (1ULL << (63 - 18))
+#define FACILITY_EXT_IMM (1ULL << (63 - 21))
+#define FACILITY_GEN_INST_EXT (1ULL << (63 - 34))
+
+static uint64_t facilities;
+
static void patch_reloc(uint8_t *code_ptr, int type,
tcg_target_long value, tcg_target_long addend)
{
@@ -1177,6 +1188,106 @@ static const TCGTargetOpDef s390_op_defs[] = {
{ -1 },
};
+/* ??? Linux kernels provide an AUXV entry AT_HWCAP that provides most of
+ this information. However, getting at that entry is not easy this far
+ away from main. Our options are: start searching from environ, but
+ that fails as soon as someone does a setenv in between. Read the data
+ from /proc/self/auxv. Or do the probing ourselves. The only thing
+ extra that AT_HWCAP gives us is HWCAP_S390_HIGH_GPRS, which indicates
+ that the kernel saves all 64-bits of the registers around traps while
+ in 31-bit mode. But this is true of all "recent" kernels (ought to dig
+ back and see from when this might not be true). */
+
+#include <signal.h>
+
+static volatile sig_atomic_t got_sigill;
+
+static void sigill_handler(int sig)
+{
+ got_sigill = 1;
+}
+
+static void query_facilities(void)
+{
+ struct sigaction sa_old, sa_new;
+ register int r0 __asm__("0");
+ register void *r1 __asm__("1");
+ int fail;
+
+ memset(&sa_new, 0, sizeof(sa_new));
+ sa_new.sa_handler = sigill_handler;
+ sigaction(SIGILL, &sa_new, &sa_old);
+
+ /* First, try STORE FACILITY LIST EXTENDED. If this is present, then
+ we need not do any more probing. Unfortunately, this itself is an
+ extension and the original STORE FACILITY LIST instruction is
+ kernel-only, storing its results at absolute address 200. */
+ /* stfle 0(%r1) */
+ r1 = &facilities;
+ asm volatile(".word 0xb2b0,0x1000"
+ : "=r"(r0) : "0"(0), "r"(r1) : "memory", "cc");
+
+ if (got_sigill) {
+ /* STORE FACILITY EXTENDED is not available. Probe for one of each
+ kind of instruction that we're interested in. */
+ /* ??? Possibly some of these are in practice never present unless
+ the store-facility-extended facility is also present. But since
+ that isn't documented it's just better to probe for each. */
+
+ /* Test for z/Architecture. Required even in 31-bit mode. */
+ got_sigill = 0;
+ /* agr %r0,%r0 */
+ asm volatile(".word 0xb908,0x0000" : "=r"(r0) : : "cc");
+ if (!got_sigill) {
+ facilities |= FACILITY_ZARCH | FACILITY_ZARCH_ACTIVE;
+ }
+
+ /* Test for long displacement. */
+ got_sigill = 0;
+ /* ly %r0,0(%r1) */
+ r1 = &facilities;
+ asm volatile(".word 0xe300,0x1000,0x0058"
+ : "=r"(r0) : "r"(r1) : "cc");
+ if (!got_sigill) {
+ facilities |= FACILITY_LONG_DISP;
+ }
+
+ /* Test for extended immediates. */
+ got_sigill = 0;
+ /* afi %r0,0 */
+ asm volatile(".word 0xc209,0x0000,0x0000" : : : "cc");
+ if (!got_sigill) {
+ facilities |= FACILITY_EXT_IMM;
+ }
+
+ /* Test for general-instructions-extension. */
+ got_sigill = 0;
+ /* msfi %r0,1 */
+ asm volatile(".word 0xc201,0x0000,0x0001");
+ if (!got_sigill) {
+ facilities |= FACILITY_GEN_INST_EXT;
+ }
+ }
+
+ sigaction(SIGILL, &sa_old, NULL);
+
+ /* The translator currently uses these extensions unconditionally.
+ Pruning this back to the base ESA/390 architecture doesn't seem
+ worthwhile, since even the KVM target requires z/Arch. */
+ fail = 0;
+ if ((facilities & FACILITY_ZARCH_ACTIVE) == 0) {
+ fprintf(stderr, "TCG: z/Arch facility is required\n");
+ fail = 1;
+ }
+ if ((facilities & FACILITY_LONG_DISP) == 0) {
+ fprintf(stderr, "TCG: long-displacement facility is required\n");
+ fail = 1;
+ }
+ if (fail) {
+ exit(-1);
+ }
+}
+
void tcg_target_init(TCGContext *s)
{
#if !defined(CONFIG_USER_ONLY)
@@ -1186,6 +1297,8 @@ void tcg_target_init(TCGContext *s)
}
#endif
+ query_facilities();
+
tcg_regset_set32(tcg_target_available_regs[TCG_TYPE_I32], 0, 0xffff);
tcg_regset_set32(tcg_target_available_regs[TCG_TYPE_I64], 0, 0xffff);
--
1.7.0.1
