From 6d88baf18653ff8826db3dd840a6b372d3477280 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@redhat.com>
Date: Tue, 4 Jun 2019 11:30:07 +0200
Subject: [PATCH] linux-user: elf: ELF_HWCAP for s390x

Let's add all HWCAPs that we can support under TCG right now, when the
respective CPU facilities are enabled.

Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Laurent Vivier <laurent@vivier.eu>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Laurent Vivier <laurent@vivier.eu>
Cc: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 include/elf.h        |  1 +
 linux-user/elfload.c | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/include/elf.h b/include/elf.h
index ea7708a4ea..3501e0c8d0 100644
--- a/include/elf.h
+++ b/include/elf.h
@@ -598,6 +598,7 @@ typedef struct {
 #define HWCAP_S390_ETF3EH       256
 #define HWCAP_S390_HIGH_GPRS    512
 #define HWCAP_S390_TE           1024
+#define HWCAP_S390_VXRS         2048
 
 /* M68K specific definitions. */
 /* We use the top 24 bits to encode information about the
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index a57b7049dd..5451d262ec 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1308,6 +1308,34 @@ static inline void init_thread(struct target_pt_regs *regs,
 #define ELF_DATA	ELFDATA2MSB
 #define ELF_ARCH	EM_S390
 
+#include "elf.h"
+
+#define ELF_HWCAP get_elf_hwcap()
+
+#define GET_FEATURE(_feat, _hwcap) \
+    do { if (s390_has_feat(_feat)) { hwcap |= _hwcap; } } while (0)
+
+static uint32_t get_elf_hwcap(void)
+{
+    /*
+     * Let's assume we always have esan3 and zarch.
+     * 31-bit processes can use 64-bit registers (high gprs).
+     */
+    uint32_t hwcap = HWCAP_S390_ESAN3 | HWCAP_S390_ZARCH | HWCAP_S390_HIGH_GPRS;
+
+    GET_FEATURE(S390_FEAT_STFLE, HWCAP_S390_STFLE);
+    GET_FEATURE(S390_FEAT_MSA, HWCAP_S390_MSA);
+    GET_FEATURE(S390_FEAT_LONG_DISPLACEMENT, HWCAP_S390_LDISP);
+    GET_FEATURE(S390_FEAT_EXTENDED_IMMEDIATE, HWCAP_S390_EIMM);
+    if (s390_has_feat(S390_FEAT_EXTENDED_TRANSLATION_3) &&
+        s390_has_feat(S390_FEAT_ETF3_ENH)) {
+        hwcap |= HWCAP_S390_ETF3EH;
+    }
+    GET_FEATURE(S390_FEAT_VECTOR, HWCAP_S390_VXRS);
+
+    return hwcap;
+}
+
 static inline void init_thread(struct target_pt_regs *regs, struct image_info *infop)
 {
     regs->psw.addr = infop->entry;