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From:   Anshuman Khandual <anshuman.khandual@arm.com>
To:     linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mm@kvack.org, akpm@linux-foundation.org, will.deacon@arm.com,
        catalin.marinas@arm.com
Cc:     mhocko@suse.com, mgorman@techsingularity.net, james.morse@arm.com,
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        logang@deltatee.com, pasha.tatashin@oracle.com, david@redhat.com,
        cai@lca.pw
Subject: [PATCH 6/6] arm64/mm: Enable ZONE_DEVICE
Date:   Wed,  3 Apr 2019 10:00:06 +0530
Message-Id: <1554265806-11501-7-git-send-email-anshuman.khandual@arm.com>
In-Reply-To: <1554265806-11501-1-git-send-email-anshuman.khandual@arm.com>
References: <1554265806-11501-1-git-send-email-anshuman.khandual@arm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Arch implementation for functions which create or destroy vmemmap mapping
(vmemmap_populate, vmemmap_free) can comprehend and allocate from inside
device memory range through driver provided vmem_altmap structure which
fulfils all requirements to enable ZONE_DEVICE on the platform. Hence just
enable ZONE_DEVICE by subscribing to ARCH_HAS_ZONE_DEVICE. But this is only
applicable for ARM64_4K_PAGES (ARM64_SWAPPER_USES_SECTION_MAPS) only which
creates vmemmap section mappings and utilize vmem_altmap structure.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/arm64/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index db3e625..b5d8cf5 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -31,6 +31,7 @@ config ARM64
 	select ARCH_HAS_SYSCALL_WRAPPER
 	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
+	select ARCH_HAS_ZONE_DEVICE if ARM64_4K_PAGES
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_INLINE_READ_LOCK if !PREEMPT
 	select ARCH_INLINE_READ_LOCK_BH if !PREEMPT
-- 
2.7.4