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From:   Song Shuai <suagrfillet@gmail.com>
To:     paul.walmsley@sifive.com, palmer@dabbelt.com,
        aou@eecs.berkeley.edu, conor.dooley@microchip.com,
        ajones@ventanamicro.com, sunilvl@ventanamicro.com,
        heiko.stuebner@vrull.eu, apatel@ventanamicro.com,
        suagrfillet@gmail.com, evan@rivosinc.com, greentime.hu@sifive.com,
        leyfoon.tan@starfivetech.com
Cc:     linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] riscv: BUG_ON() for no cpu nodes in setup_smp
Date:   Thu, 29 Jun 2023 18:58:39 +0800
Message-Id: <20230629105839.1160895-1-suagrfillet@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

When booting with ACPI tables, the tiny devictree created by
EFI Stub doesn't provide cpu nodes.

In setup_smp(), of_parse_and_init_cpus() will bug on !found_boot_cpu
if acpi_disabled. That's unclear, so bug for no cpu nodes before
of_parse_and_init_cpus().

Signed-off-by: Song Shuai <suagrfillet@gmail.com>
---
 arch/riscv/kernel/smpboot.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 6ca2b5309aab..243a7b533ad7 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -187,8 +187,13 @@ static void __init of_parse_and_init_cpus(void)
 
 void __init setup_smp(void)
 {
-	if (acpi_disabled)
+	if (acpi_disabled) {
+		/* When booting with ACPI tables, the devictree created by EFI Stub
+		 * doesn't provide cpu nodes. So BUG here for any acpi_disabled.
+		 */
+		BUG_ON(!of_get_next_cpu_node(NULL));
 		of_parse_and_init_cpus();
+	}
 	else
 		acpi_parse_and_init_cpus();
 }
-- 
2.20.1