From:   guoren@kernel.org
To:     guoren@kernel.org, anup@brainfault.org, palmer@dabbelt.com,
        atishp@rivosinc.com
Cc:     linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
        linux-doc@vger.kernel.org, Guo Ren <guoren@linux.alibaba.com>,
        Anup Patel <anup.patel@wdc.com>
Subject: [RFC PATCH 3/3] riscv: Add riscv.fwsz kernel parameter
Date:   Tue, 23 Nov 2021 09:57:17 +0800
Message-Id: <20211123015717.542631-4-guoren@kernel.org>
In-Reply-To: <20211123015717.542631-1-guoren@kernel.org>
References: <20211123015717.542631-1-guoren@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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From: Guo Ren <guoren@linux.alibaba.com>

The firmware of riscv (such as opensbi) occupy 2MB(64bit) /
4MB(32bit) in Linux. It's very wasteful to small memory footprint
soc chip such as Allwinner D1s/F133. The kernel parameter gives a
chance to users to set the proper size of the firmware and get
more than 1.5MB of memory.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Anup Patel <anup.patel@wdc.com>
Cc: Atish Patra <atishp@rivosinc.com>
---
 Documentation/admin-guide/kernel-parameters.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 9725c546a0d4..ee505743c8f4 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4964,6 +4964,9 @@
 			[KNL] Disable ring 3 MONITOR/MWAIT feature on supported
 			CPUs.
 
+	riscv.fwsz=nn[KMG]
+			[RISC-V] Determine firmware size to save memory
+
 	ro		[KNL] Mount root device read-only on boot
 
 	rodata=		[KNL]
-- 
2.25.1