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From:   Xianting Tian <xianting.tian@linux.alibaba.com>
To:     mick@ics.forth.gr, paul.walmsley@sifive.com, palmer@dabbelt.com,
        aou@eecs.berkeley.edu, anup@brainfault.org,
        akpm@linux-foundation.org, wangkefeng.wang@huawei.com,
        rppt@kernel.org, david@redhat.com, wangborong@cdjrlc.com,
        twd2.me@gmail.com, seanjc@google.com, alex@ghiti.fr,
        petr.pavlu@suse.com, atishp@rivosinc.com
Cc:     linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        jianghuaming.jhm@alibaba-inc.com, guoren@kernel.org,
        heiko@sntech.de, Xianting Tian <xianting.tian@linux.alibaba.com>
Subject: [PATCH v3] RISC-V: Mark IORESOURCE_EXCLUSIVE for reserved mem instead of IORESOURCE_BUSY
Date:   Wed, 18 May 2022 09:34:28 +0800
Message-Id: <20220518013428.1338983-1-xianting.tian@linux.alibaba.com>
Precedence: bulk

Commit 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree")
marked IORESOURCE_BUSY for reserved memory, which caused resource map
failed in subsequent operations of related driver, so remove the
IORESOURCE_BUSY flag. In order to prohibit userland mapping reserved
memory, mark IORESOURCE_EXCLUSIVE for it.

The code to reproduce the issue,
dts:
        mem0: memory@a0000000 {
                reg = <0x0 0xa0000000 0 0x1000000>;
                no-map;
        };

        &test {
                status = "okay";
                memory-region = <&mem0>;
        };

code:
        np = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
        ret = of_address_to_resource(np, 0, &r);
        base = devm_ioremap_resource(&pdev->dev, &r);
        // base = -EBUSY

Fixes: 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree")
Reported-by: Huaming Jiang <jianghuaming.jhm@alibaba-inc.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Co-developed-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com>
---
Changes from v2:
- Fix typo in commit message: casued -> caused
- Remove Reviewed-by of Nick Kossifidis, who didn't give Reviewed-by actually
- Add Co-developed-by of Nick

Changes from v1:
- Mark reserved memory as IORESOURCE_EXCLUSIVE, suggested by Nick
---
 arch/riscv/kernel/setup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 834eb652a7b9..e0a00739bd13 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -189,7 +189,7 @@ static void __init init_resources(void)
 		res = &mem_res[res_idx--];
 
 		res->name = "Reserved";
-		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+		res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
 		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
 		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
 
@@ -214,7 +214,7 @@ static void __init init_resources(void)
 
 		if (unlikely(memblock_is_nomap(region))) {
 			res->name = "Reserved";
-			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+			res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
 		} else {
 			res->name = "System RAM";
 			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
-- 
2.17.1