linux-user/host/aarch64: Populate host_signal.h

Split host_signal_pc and host_signal_write out of user-exec.c.
Drop the *BSD code, to be re-created under bsd-user/ later.

Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

2 files changed, 75 insertions, 94 deletions

diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
index fabc8855a9..5cdbfab35b 100644
--- a/accel/tcg/user-exec.c
+++ b/accel/tcg/user-exec.c
@@ -253,99 +253,7 @@ void *probe_access(CPUArchState *env, target_ulong addr, int size,
     return size ? g2h(env_cpu(env), addr) : NULL;
 }
 
-#if defined(__aarch64__)
-
-#if defined(__NetBSD__)
-
-#include <ucontext.h>
-#include <sys/siginfo.h>
-
-int cpu_signal_handler(int host_signum, void *pinfo, void *puc)
-{
-    ucontext_t *uc = puc;
-    siginfo_t *si = pinfo;
-    unsigned long pc;
-    int is_write;
-    uint32_t esr;
-
-    pc = uc->uc_mcontext.__gregs[_REG_PC];
-    esr = si->si_trap;
-
-    /*
-     * siginfo_t::si_trap is the ESR value, for data aborts ESR.EC
-     * is 0b10010x: then bit 6 is the WnR bit
-     */
-    is_write = extract32(esr, 27, 5) == 0x12 && extract32(esr, 6, 1) == 1;
-    return handle_cpu_signal(pc, si, is_write, &uc->uc_sigmask);
-}
-
-#else
-
-#ifndef ESR_MAGIC
-/* Pre-3.16 kernel headers don't have these, so provide fallback definitions */
-#define ESR_MAGIC 0x45535201
-struct esr_context {
-    struct _aarch64_ctx head;
-    uint64_t esr;
-};
-#endif
-
-static inline struct _aarch64_ctx *first_ctx(ucontext_t *uc)
-{
-    return (struct _aarch64_ctx *)&uc->uc_mcontext.__reserved;
-}
-
-static inline struct _aarch64_ctx *next_ctx(struct _aarch64_ctx *hdr)
-{
-    return (struct _aarch64_ctx *)((char *)hdr + hdr->size);
-}
-
-int cpu_signal_handler(int host_signum, void *pinfo, void *puc)
-{
-    siginfo_t *info = pinfo;
-    ucontext_t *uc = puc;
-    uintptr_t pc = uc->uc_mcontext.pc;
-    bool is_write;
-    struct _aarch64_ctx *hdr;
-    struct esr_context const *esrctx = NULL;
-
-    /* Find the esr_context, which has the WnR bit in it */
-    for (hdr = first_ctx(uc); hdr->magic; hdr = next_ctx(hdr)) {
-        if (hdr->magic == ESR_MAGIC) {
-            esrctx = (struct esr_context const *)hdr;
-            break;
-        }
-    }
-
-    if (esrctx) {
-        /* For data aborts ESR.EC is 0b10010x: then bit 6 is the WnR bit */
-        uint64_t esr = esrctx->esr;
-        is_write = extract32(esr, 27, 5) == 0x12 && extract32(esr, 6, 1) == 1;
-    } else {
-        /*
-         * Fall back to parsing instructions; will only be needed
-         * for really ancient (pre-3.16) kernels.
-         */
-        uint32_t insn = *(uint32_t *)pc;
-
-        is_write = ((insn & 0xbfff0000) == 0x0c000000   /* C3.3.1 */
-                    || (insn & 0xbfe00000) == 0x0c800000   /* C3.3.2 */
-                    || (insn & 0xbfdf0000) == 0x0d000000   /* C3.3.3 */
-                    || (insn & 0xbfc00000) == 0x0d800000   /* C3.3.4 */
-                    || (insn & 0x3f400000) == 0x08000000   /* C3.3.6 */
-                    || (insn & 0x3bc00000) == 0x39000000   /* C3.3.13 */
-                    || (insn & 0x3fc00000) == 0x3d800000   /* ... 128bit */
-                    /* Ignore bits 10, 11 & 21, controlling indexing.  */
-                    || (insn & 0x3bc00000) == 0x38000000   /* C3.3.8-12 */
-                    || (insn & 0x3fe00000) == 0x3c800000   /* ... 128bit */
-                    /* Ignore bits 23 & 24, controlling indexing.  */
-                    || (insn & 0x3a400000) == 0x28000000); /* C3.3.7,14-16 */
-    }
-    return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
-}
-#endif
-
-#elif defined(__s390__)
+#if defined(__s390__)
 
 int cpu_signal_handler(int host_signum, void *pinfo,
                        void *puc)
diff --git a/linux-user/host/aarch64/host-signal.h b/linux-user/host/aarch64/host-signal.h
index f4b4d65031..0c0b08383a 100644
--- a/linux-user/host/aarch64/host-signal.h
+++ b/linux-user/host/aarch64/host-signal.h
@@ -1 +1,74 @@
-#define HOST_SIGNAL_PLACEHOLDER
+/*
+ * host-signal.h: signal info dependent on the host architecture
+ *
+ * Copyright (c) 2003-2005 Fabrice Bellard
+ * Copyright (c) 2021 Linaro Limited
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef AARCH64_HOST_SIGNAL_H
+#define AARCH64_HOST_SIGNAL_H
+
+/* Pre-3.16 kernel headers don't have these, so provide fallback definitions */
+#ifndef ESR_MAGIC
+#define ESR_MAGIC 0x45535201
+struct esr_context {
+    struct _aarch64_ctx head;
+    uint64_t esr;
+};
+#endif
+
+static inline struct _aarch64_ctx *first_ctx(ucontext_t *uc)
+{
+    return (struct _aarch64_ctx *)&uc->uc_mcontext.__reserved;
+}
+
+static inline struct _aarch64_ctx *next_ctx(struct _aarch64_ctx *hdr)
+{
+    return (struct _aarch64_ctx *)((char *)hdr + hdr->size);
+}
+
+static inline uintptr_t host_signal_pc(ucontext_t *uc)
+{
+    return uc->uc_mcontext.pc;
+}
+
+static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc)
+{
+    struct _aarch64_ctx *hdr;
+    uint32_t insn;
+
+    /* Find the esr_context, which has the WnR bit in it */
+    for (hdr = first_ctx(uc); hdr->magic; hdr = next_ctx(hdr)) {
+        if (hdr->magic == ESR_MAGIC) {
+            struct esr_context const *ec = (struct esr_context const *)hdr;
+            uint64_t esr = ec->esr;
+
+            /* For data aborts ESR.EC is 0b10010x: then bit 6 is the WnR bit */
+            return extract32(esr, 27, 5) == 0x12 && extract32(esr, 6, 1) == 1;
+        }
+    }
+
+    /*
+     * Fall back to parsing instructions; will only be needed
+     * for really ancient (pre-3.16) kernels.
+     */
+    insn = *(uint32_t *)host_signal_pc(uc);
+
+    return (insn & 0xbfff0000) == 0x0c000000   /* C3.3.1 */
+        || (insn & 0xbfe00000) == 0x0c800000   /* C3.3.2 */
+        || (insn & 0xbfdf0000) == 0x0d000000   /* C3.3.3 */
+        || (insn & 0xbfc00000) == 0x0d800000   /* C3.3.4 */
+        || (insn & 0x3f400000) == 0x08000000   /* C3.3.6 */
+        || (insn & 0x3bc00000) == 0x39000000   /* C3.3.13 */
+        || (insn & 0x3fc00000) == 0x3d800000   /* ... 128bit */
+        /* Ignore bits 10, 11 & 21, controlling indexing.  */
+        || (insn & 0x3bc00000) == 0x38000000   /* C3.3.8-12 */
+        || (insn & 0x3fe00000) == 0x3c800000   /* ... 128bit */
+        /* Ignore bits 23 & 24, controlling indexing.  */
+        || (insn & 0x3a400000) == 0x28000000; /* C3.3.7,14-16 */
+}
+
+#endif