[RISU PATCH v4 21/29] aarch64: Use arch_init to configure sve

[Richard Henderson <richard.henderson@linaro.org>]

Adjust some of the aarch64 code to look at the reginfo struct
instead of looking at test_sve, so that we do not need to pass
the --test-sve option in order to dump sve trace files.

Diagnose EINVAL as either cpu or kernel does not support SVE.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 risu.h                 |  1 +
 risu.c                 |  3 +++
 risu_reginfo_aarch64.c | 31 ++++++++++++++++++++-----------
 risu_reginfo_arm.c     |  4 ++++
 risu_reginfo_i386.c    |  4 ++++
 risu_reginfo_m68k.c    |  4 ++++
 risu_reginfo_ppc64.c   |  4 ++++
 7 files changed, 40 insertions(+), 11 deletions(-)

diff --git a/risu.h b/risu.h
index 3cad3d5..bdb70c1 100644
--- a/risu.h
+++ b/risu.h
@@ -23,6 +23,7 @@
 extern const struct option * const arch_long_opts;
 extern const char * const arch_extra_help;
 void process_arch_opt(int opt, const char *arg);
+void arch_init(void);
 #define FIRST_ARCH_OPT   0x100
 
 /* GCC computed include to pull in the correct risu_reginfo_*.h for
diff --git a/risu.c b/risu.c
index a70b778..1c096a8 100644
--- a/risu.c
+++ b/risu.c
@@ -617,6 +617,9 @@ int main(int argc, char **argv)
 
     load_image(imgfile);
 
+    /* E.g. select requested SVE vector length. */
+    arch_init();
+
     if (ismaster) {
         return master();
     } else {
diff --git a/risu_reginfo_aarch64.c b/risu_reginfo_aarch64.c
index 81a77ba..be47980 100644
--- a/risu_reginfo_aarch64.c
+++ b/risu_reginfo_aarch64.c
@@ -19,6 +19,7 @@
 #include <stdbool.h>
 #include <inttypes.h>
 #include <assert.h>
+#include <errno.h>
 #include <sys/prctl.h>
 
 #include "risu.h"
@@ -37,8 +38,6 @@ const char * const arch_extra_help
 
 void process_arch_opt(int opt, const char *arg)
 {
-    long want, got;
-
     assert(opt == FIRST_ARCH_OPT);
     test_sve = strtol(arg, 0, 10);
 
@@ -46,16 +45,26 @@ void process_arch_opt(int opt, const char *arg)
         fprintf(stderr, "Invalid value for VQ (1-%d)\n", SVE_VQ_MAX);
         exit(EXIT_FAILURE);
     }
-    want = sve_vl_from_vq(test_sve);
-    got = prctl(PR_SVE_SET_VL, want);
-    if (want != got) {
-        if (got < 0) {
-            perror("prctl PR_SVE_SET_VL");
-        } else {
-            fprintf(stderr, "Unsupported value for VQ (%d != %d)\n",
-                    test_sve, (int)sve_vq_from_vl(got));
+}
+
+void arch_init(void)
+{
+    long want, got;
+
+    if (test_sve) {
+        want = sve_vl_from_vq(test_sve);
+        got = prctl(PR_SVE_SET_VL, want);
+        if (want != got) {
+            if (got >= 0) {
+                fprintf(stderr, "Unsupported VQ for SVE (%d != %d)\n",
+                        test_sve, (int)sve_vq_from_vl(got));
+            } else if (errno == EINVAL) {
+                fprintf(stderr, "System does not support SVE\n");
+            } else {
+                perror("prctl PR_SVE_SET_VL");
+            }
+            exit(EXIT_FAILURE);
         }
-        exit(EXIT_FAILURE);
     }
 }
 
diff --git a/risu_reginfo_arm.c b/risu_reginfo_arm.c
index 47c52e8..202120b 100644
--- a/risu_reginfo_arm.c
+++ b/risu_reginfo_arm.c
@@ -36,6 +36,10 @@ void process_arch_opt(int opt, const char *arg)
     abort();
 }
 
+void arch_init(void)
+{
+}
+
 int reginfo_size(struct reginfo *ri)
 {
     return sizeof(*ri);
diff --git a/risu_reginfo_i386.c b/risu_reginfo_i386.c
index 50505ab..e9730be 100644
--- a/risu_reginfo_i386.c
+++ b/risu_reginfo_i386.c
@@ -74,6 +74,10 @@ void process_arch_opt(int opt, const char *arg)
     }
 }
 
+void arch_init(void)
+{
+}
+
 int reginfo_size(struct reginfo *ri)
 {
     return sizeof(*ri);
diff --git a/risu_reginfo_m68k.c b/risu_reginfo_m68k.c
index 4eb30cd..4c25e77 100644
--- a/risu_reginfo_m68k.c
+++ b/risu_reginfo_m68k.c
@@ -23,6 +23,10 @@ void process_arch_opt(int opt, const char *arg)
     abort();
 }
 
+void arch_init(void)
+{
+}
+
 int reginfo_size(struct reginfo *ri)
 {
     return sizeof(*ri);
diff --git a/risu_reginfo_ppc64.c b/risu_reginfo_ppc64.c
index 39e8f1c..c80e387 100644
--- a/risu_reginfo_ppc64.c
+++ b/risu_reginfo_ppc64.c
@@ -32,6 +32,10 @@ void process_arch_opt(int opt, const char *arg)
     abort();
 }
 
+void arch_init(void)
+{
+}
+
 int reginfo_size(struct reginfo *ri)
 {
     return sizeof(*ri);
-- 
2.34.1