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From:   Paul Cercueil <paul@crapouillou.net>
To:     Ralf Baechle <ralf@linux-mips.org>,
        Paul Burton <paul.burton@mips.com>,
        James Hogan <jhogan@kernel.org>
Cc:     od@zcrc.me, linux-mips@vger.kernel.org,
        linux-kernel@vger.kernel.org, Daniel Silsby <dansilsby@gmail.com>,
        Paul Cercueil <paul@crapouillou.net>
Subject: [PATCH 1/5] MIPS: Disallow CPU_SUPPORTS_HUGEPAGES for XPA,EVA
Date:   Mon, 15 Jul 2019 17:39:59 -0400
Message-Id: <20190715214003.9714-1-paul@crapouillou.net>
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From: Daniel Silsby <dansilsby@gmail.com>

In preparation for 32-bit MIPS huge page support.

EVA,XPA are extended-addressing modes for 32-bit MIPS systems. Because
huge pages aren't currently supported in 32-bit MIPS, this doesn't take
any features away from EVA,XPA-enabled systems. However, the soon-to-
come 32-bit MIPS huge page support doesn't yet support them.

This also disables CPU_SUPPORTS_HUGEPAGES for the small number of 32-bit
MIPS CPUs from Alchemy/Netlogic that support a custom 36-bit extended
addressing. It's unknown if they even support huge pages in hardware.

Signed-off-by: Daniel Silsby <dansilsby@gmail.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
 arch/mips/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index d50fafd7bf3a..ff5f1314241e 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2110,6 +2110,7 @@ config CPU_SUPPORTS_ADDRWINCFG
 	bool
 config CPU_SUPPORTS_HUGEPAGES
 	bool
+	depends on !(32BIT && (ARCH_PHYS_ADDR_T_64BIT || EVA))
 config CPU_SUPPORTS_UNCACHED_ACCELERATED
 	bool
 config MIPS_PGD_C0_CONTEXT
-- 
2.21.0.593.g511ec345e18