From 03219fba43d7d642e46320906761a5a2e828a573 Mon Sep 17 00:00:00 2001
From: Hans Petter Selasky <hselasky@FreeBSD.org>
Date: Mon, 16 May 2016 09:16:15 +0000
Subject: [PATCH] Properly implement "cpu_has_clflush" macro.

Suggested by:	kib, jhb
MFC after:	1 week
Sponsored by:	Mellanox Technologies
---
 sys/compat/linuxkpi/common/include/linux/kernel.h |  6 +++++-
 sys/compat/linuxkpi/common/src/linux_compat.c     | 12 ++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/sys/compat/linuxkpi/common/include/linux/kernel.h b/sys/compat/linuxkpi/common/include/linux/kernel.h
index 040c7de43b8..9f280ceab37 100644
--- a/sys/compat/linuxkpi/common/include/linux/kernel.h
+++ b/sys/compat/linuxkpi/common/include/linux/kernel.h
@@ -258,7 +258,11 @@
 #define	smp_processor_id()	PCPU_GET(cpuid)
 #define	num_possible_cpus()	mp_ncpus
 #define	num_online_cpus()	mp_ncpus
-#define	cpu_has_clflush		(1)
+
+#if defined(__i386__) || defined(__amd64__)
+extern bool linux_cpu_has_clflush;
+#define	cpu_has_clflush		linux_cpu_has_clflush
+#endif
 
 typedef struct pm_message {
         int event;
diff --git a/sys/compat/linuxkpi/common/src/linux_compat.c b/sys/compat/linuxkpi/common/src/linux_compat.c
index 0584f23ee9e..77b18a36e5e 100644
--- a/sys/compat/linuxkpi/common/src/linux_compat.c
+++ b/sys/compat/linuxkpi/common/src/linux_compat.c
@@ -51,6 +51,10 @@ __FBSDID("$FreeBSD$");
 
 #include <machine/stdarg.h>
 
+#if defined(__i386__) || defined(__amd64__)
+#include <machine/md_var.h>
+#endif
+
 #include <linux/kobject.h>
 #include <linux/device.h>
 #include <linux/slab.h>
@@ -67,6 +71,7 @@ __FBSDID("$FreeBSD$");
 #include <linux/rcupdate.h>
 #include <linux/interrupt.h>
 #include <linux/uaccess.h>
+#include <linux/kernel.h>
 
 #include <vm/vm_pager.h>
 
@@ -1362,12 +1367,19 @@ linux_irq_handler(void *ent)
 	irqe->handler(irqe->irq, irqe->arg);
 }
 
+#if defined(__i386__) || defined(__amd64__)
+bool linux_cpu_has_clflush;
+#endif
+
 static void
 linux_compat_init(void *arg)
 {
 	struct sysctl_oid *rootoid;
 	int i;
 
+#if defined(__i386__) || defined(__amd64__)
+	linux_cpu_has_clflush = (cpu_feature & CPUID_CLFSH);
+#endif
 	sx_init(&linux_global_rcu_lock, "LinuxGlobalRCU");
 
 	rootoid = SYSCTL_ADD_ROOT_NODE(NULL,