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From: Andrew Jones <ajones@ventanamicro.com>
To: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-doc@vger.kernel.org
Cc: paul.walmsley@sifive.com, palmer@dabbelt.com,
	charlie@rivosinc.com, cleger@rivosinc.com, alex@ghiti.fr,
	Anup Patel <apatel@ventanamicro.com>,
	corbet@lwn.net, Alexandre Ghiti <alexghiti@rivosinc.com>
Subject: [PATCH v2 3/8] riscv: Fix check_unaligned_access_all_cpus
Date: Fri, 21 Feb 2025 15:57:22 +0100	[thread overview]
Message-ID: <20250221145718.115076-13-ajones@ventanamicro.com> (raw)
In-Reply-To: <20250221145718.115076-10-ajones@ventanamicro.com>

check_vector_unaligned_access_emulated_all_cpus(), like its name
suggests, will return true when all cpus emulate unaligned vector
accesses. If the function returned false it may have been because
vector isn't supported at all (!has_vector()) or because at least
one cpu doesn't emulate unaligned vector accesses. Since false may
be returned for two cases, checking for it isn't sufficient when
attempting to determine if we should proceed with the vector speed
check. Move the !has_vector() functionality to
check_unaligned_access_all_cpus() in order for
check_vector_unaligned_access_emulated_all_cpus() to return false
for a single case.

Fixes: e7c9d66e313b ("RISC-V: Report vector unaligned access speed hwprobe")
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
---
 arch/riscv/kernel/traps_misaligned.c       |  6 ------
 arch/riscv/kernel/unaligned_access_speed.c | 11 +++++++----
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c
index aacbd9d7196e..4354c87c0376 100644
--- a/arch/riscv/kernel/traps_misaligned.c
+++ b/arch/riscv/kernel/traps_misaligned.c
@@ -609,12 +609,6 @@ bool __init check_vector_unaligned_access_emulated_all_cpus(void)
 {
 	int cpu;
 
-	if (!has_vector()) {
-		for_each_online_cpu(cpu)
-			per_cpu(vector_misaligned_access, cpu) = RISCV_HWPROBE_MISALIGNED_VECTOR_UNSUPPORTED;
-		return false;
-	}
-
 	schedule_on_each_cpu(check_vector_unaligned_access_emulated);
 
 	for_each_online_cpu(cpu)
diff --git a/arch/riscv/kernel/unaligned_access_speed.c b/arch/riscv/kernel/unaligned_access_speed.c
index 161964cf2abc..02b485dc4bc4 100644
--- a/arch/riscv/kernel/unaligned_access_speed.c
+++ b/arch/riscv/kernel/unaligned_access_speed.c
@@ -403,13 +403,16 @@ static int __init vec_check_unaligned_access_speed_all_cpus(void *unused __alway
 
 static int __init check_unaligned_access_all_cpus(void)
 {
-	bool all_cpus_emulated, all_cpus_vec_unsupported;
+	bool all_cpus_emulated;
+	int cpu;
 
 	all_cpus_emulated = check_unaligned_access_emulated_all_cpus();
-	all_cpus_vec_unsupported = check_vector_unaligned_access_emulated_all_cpus();
 
-	if (!all_cpus_vec_unsupported &&
-	    IS_ENABLED(CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS)) {
+	if (!has_vector()) {
+		for_each_online_cpu(cpu)
+			per_cpu(vector_misaligned_access, cpu) = RISCV_HWPROBE_MISALIGNED_VECTOR_UNSUPPORTED;
+	} else if (!check_vector_unaligned_access_emulated_all_cpus() &&
+		   IS_ENABLED(CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS)) {
 		kthread_run(vec_check_unaligned_access_speed_all_cpus,
 			    NULL, "vec_check_unaligned_access_speed_all_cpus");
 	}
-- 
2.48.1


  parent reply	other threads:[~2025-02-21 14:57 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-02-21 14:57 [PATCH v2 0/8] riscv: Unaligned access speed probing fixes and skipping Andrew Jones
2025-02-21 14:57 ` [PATCH v2 1/8] riscv: Annotate unaligned access init functions Andrew Jones
2025-02-21 14:57 ` [PATCH v2 2/8] riscv: Fix riscv_online_cpu_vec Andrew Jones
2025-02-21 14:57 ` Andrew Jones [this message]
2025-02-21 14:57 ` [PATCH v2 4/8] riscv: Change check_unaligned_access_speed_all_cpus to void Andrew Jones
2025-02-21 14:57 ` [PATCH v2 5/8] riscv: Fix set up of cpu hotplug callbacks Andrew Jones
2025-02-21 14:57 ` [PATCH v2 6/8] riscv: Fix set up of vector cpu hotplug callback Andrew Jones
2025-02-21 14:57 ` [PATCH v2 7/8] riscv: Add parameter for skipping access speed tests Andrew Jones
2025-02-21 14:57 ` [PATCH v2 8/8] Documentation/kernel-parameters: Add riscv unaligned speed parameters Andrew Jones

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