Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Michal Suchanek <msuchanek@suse.de>
To:     linuxppc-dev@lists.ozlabs.org
Cc:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Peter Zijlstra <peterz@infradead.org>,
        Michal Suchanek <msuchanek@suse.de>,
        Kate Stewart <kstewart@linuxfoundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Philippe Ombredanne <pombredanne@nexb.com>,
        Nicholas Piggin <npiggin@gmail.com>,
        "Tobin C. Harding" <me@tobin.cc>,
        Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>,
        David Gibson <david@gibson.dropbear.id.au>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Michael Neuling <mikey@neuling.org>,
        "Oliver O'Halloran" <oohall@gmail.com>,
        "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>,
        Madhavan Srinivasan <maddy@linux.vnet.ibm.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Balbir Singh <bsingharora@gmail.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Christophe Leroy <christophe.leroy@c-s.fr>,
        Andrew Donnellan <andrew.donnellan@au1.ibm.com>,
        Daniel Axtens <dja@axtens.net>,
        Russell Currey <ruscur@russell.cc>,
        Joe Perches <joe@perches.com>,
        "Bryant G. Ly" <bryantly@linux.vnet.ibm.com>,
        =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@kaod.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH RFC 1/8] powerpc: Add barrier_nospec
Date:   Tue, 13 Mar 2018 19:32:59 +0100
Message-Id: <e1c146e5d43e8b2605af6e1330167d8e18d36f44.1520965380.git.msuchanek@suse.de>
In-Reply-To: <cover.1520965380.git.msuchanek@suse.de>
References: <cover.1520965380.git.msuchanek@suse.de>
In-Reply-To: <cover.1520965380.git.msuchanek@suse.de>
References: <cover.1520965380.git.msuchanek@suse.de>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Copypasta from original gmb() and rfi implementation

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
 arch/powerpc/include/asm/barrier.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index 10daa1d56e0a..8e47b3abe405 100644
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -75,6 +75,15 @@ do {									\
 	___p1;								\
 })
 
+/* TODO: add patching so this can be disabled */
+/* Prevent speculative execution past this barrier. */
+#define barrier_nospec_asm ori 31,31,0
+#ifdef __ASSEMBLY__
+#define barrier_nospec barrier_nospec_asm
+#else
+#define barrier_nospec() __asm__ __volatile__ (stringify_in_c(barrier_nospec_asm) : : :)
+#endif
+
 #include <asm-generic/barrier.h>
 
 #endif /* _ASM_POWERPC_BARRIER_H */
-- 
2.13.6