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authorRichard Henderson <rth@twiddle.net>2013-06-07 07:43:33 -0700
committerRichard Henderson <rth@twiddle.net>2013-11-30 07:45:30 +1300
commitc9baa30f42a87f61627391698f63fa4d1566d9d8 (patch)
tree012f352b06ae68c761a7f6f39ef81b1731407843 /tcg/s390
parent41d9ea80ac8455845494c889fe6ac447b39a7d64 (diff)
tcg-s390: Use qemu_getauxval in query_facilities
No need to set up a SIGILL signal handler for detection anymore. Remove a ton of sanity checks that must be true, given that we're requiring a 64-bit build (the note about 31-bit KVM is satisfied by configuring with TCI). Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'tcg/s390')
-rw-r--r--tcg/s390/tcg-target.c95
1 files changed, 12 insertions, 83 deletions
diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
index 0a4f3be0e9..248726e82f 100644
--- a/tcg/s390/tcg-target.c
+++ b/tcg/s390/tcg-target.c
@@ -31,6 +31,8 @@
#error "unsupported code generation mode"
#endif
+#include "elf.h"
+
/* ??? The translation blocks produced by TCG are generally small enough to
be entirely reachable with a 16-bit displacement. Leaving the option for
a 32-bit displacement here Just In Case. */
@@ -2233,91 +2235,18 @@ static void sigill_handler(int sig)
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_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);
+ unsigned long hwcap = qemu_getauxval(AT_HWCAP);
- /* 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");
- fprintf(stderr, "TCG: Boot with a 64-bit enabled kernel.\n");
- fail = 1;
- }
- if ((facilities & FACILITY_LONG_DISP) == 0) {
- fprintf(stderr, "TCG: long-displacement facility is required.\n");
- fail = 1;
- }
+ /* Is STORE FACILITY LIST EXTENDED available? Honestly, I believe this
+ is present on all 64-bit systems, but let's check for it anyway. */
+ if (hwcap & HWCAP_S390_STFLE) {
+ register int r0 __asm__("0");
+ register void *r1 __asm__("1");
- /* So far there's just enough support for 31-bit mode to let the
- compile succeed. This is good enough to run QEMU with KVM. */
- if (sizeof(void *) != 8) {
- fprintf(stderr, "TCG: 31-bit mode is not supported.\n");
- fail = 1;
- }
-
- if (fail) {
- exit(-1);
+ /* stfle 0(%r1) */
+ r1 = &facilities;
+ asm volatile(".word 0xb2b0,0x1000"
+ : "=r"(r0) : "0"(0), "r"(r1) : "memory", "cc");
}
}