From: Ian Campbell <ian.campbell@citrix.com>
Date: Wed, 17 Jul 2013 11:19:28 +0000 (+0100)
Subject: xen: arm: remove unnecessary cache flush in write_pte
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~6599
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=225ece46211328723a79f13152cb904c0b0f38b2;p=xen.git

xen: arm: remove unnecessary cache flush in write_pte

On a ARMv7/v8 SMP system the MMU is coherent

Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
[ ijc -- dropped the associated dsb too ]
---

diff --git a/xen/include/asm-arm/arm32/page.h b/xen/include/asm-arm/arm32/page.h
index 38bcffde6d..cf12a89ae6 100644
--- a/xen/include/asm-arm/arm32/page.h
+++ b/xen/include/asm-arm/arm32/page.h
@@ -16,10 +16,6 @@ static inline void write_pte(lpae_t *p, lpae_t pte)
         /* Safely write the entry (STRD is atomic on CPUs that support LPAE) */
         "strd %0, %H0, [%1];"
         "dsb;"
-        /* Push this cacheline to the PoC so the rest of the system sees it. */
-        STORE_CP32(1, DCCMVAC)
-        /* Ensure that the data flush is completed before proceeding */
-        "dsb;"
         : : "r" (pte.bits), "r" (p) : "memory");
 }
 
diff --git a/xen/include/asm-arm/arm64/page.h b/xen/include/asm-arm/arm64/page.h
index bd48fe3d02..9551f90844 100644
--- a/xen/include/asm-arm/arm64/page.h
+++ b/xen/include/asm-arm/arm64/page.h
@@ -11,10 +11,6 @@ static inline void write_pte(lpae_t *p, lpae_t pte)
         "dsb sy;"
         "str %0, [%1];"         /* Write the entry */
         "dsb sy;"
-        /* Push this cacheline to the PoC so the rest of the system sees it. */
-        "dc cvac, %1;"
-        /* Ensure that the data flush is completed before proceeding */
-        "dsb sy;"
         : : "r" (pte.bits), "r" (p) : "memory");
 }