Subject: [PATCH 02/12] RISC-V: MAXPHYSMEM_2GB doesn't depend on CMODEL_MEDLOW
Date:   Fri, 19 Nov 2021 08:44:03 -0800
Message-Id: <20211119164413.29052-3-palmer@rivosinc.com>
In-Reply-To: <20211119164413.29052-1-palmer@rivosinc.com>
References: <20211119164413.29052-1-palmer@rivosinc.com>
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Cc:     Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>, aou@eecs.berkeley.edu,
        anup.patel@wdc.com, heinrich.schuchardt@canonical.com,
        atish.patra@wdc.com, bin.meng@windriver.com,
        sagar.kadam@sifive.com, damien.lemoal@wdc.com, axboe@kernel.dk,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        Palmer Dabbelt <palmer@rivosinc.com>, stable@vger.kernel.org
From:   Palmer Dabbelt <palmer@rivosinc.com>
To:         linux-riscv@lists.infradead.org
Precedence: bulk

From: Palmer Dabbelt <palmer@rivosinc.com>

For non-relocatable kernels we need to be able to link the kernel at
approximately PAGE_OFFSET, thus requiring medany (as medlow requires the
code to be linked within 2GiB of 0).  The inverse doesn't apply, though:
since medany code can be linked anywhere it's fine to link it close to
0, so we can support the smaller memory config.

Fixes: de5f4b8f634b ("RISC-V: Define MAXPHYSMEM_1GB only for RV32")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

---

I found this when going through the savedefconfig diffs for the K210
defconfigs.  I'm not entirely sure they're doing the right thing here
(they should probably be setting CMODEL_LOW to take advantage of the
better code generation), but I don't have any way to test those
platforms so I don't want to change too much.
---
 arch/riscv/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 821252b65f89..61f64512dcde 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -280,7 +280,7 @@ choice
 		depends on 32BIT
 		bool "1GiB"
 	config MAXPHYSMEM_2GB
-		depends on 64BIT && CMODEL_MEDLOW
+		depends on 64BIT
 		bool "2GiB"
 	config MAXPHYSMEM_128GB
 		depends on 64BIT && CMODEL_MEDANY
-- 
2.32.0