[RFC PATCH v3 06/24] arm64/sve: Clarify role of the VQ map maintenance functions
From: Dave Martin <Dave.Martin@arm.com>
Date: 2018-12-11 23:33:09
Also in:
kvmarm
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
The roles of sve_init_vq_map(), sve_update_vq_map() and sve_verify_vq_map() are highly non-obvious to anyone who has not dug through cpufeatures.c in detail. Since the way these functions interact with each other is more important here than a full understanding of the cpufeatures code, this patch adds comments to make the functions' roles clearer. No functional change. Signed-off-by: Dave Martin <Dave.Martin@arm.com> --- Changes since RFC v2: * New patch. --- arch/arm64/kernel/fpsimd.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 64729e2..92c2331 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c@@ -647,6 +647,10 @@ static void sve_probe_vqs(DECLARE_BITMAP(map, SVE_VQ_MAX)) } } +/* + * Initialise the set of known supported VQs for the boot CPU. + * This is called during kernel boot, before secondary CPUs are brought up. + */ void __init sve_init_vq_map(void) { sve_probe_vqs(sve_vq_map);
@@ -656,6 +660,7 @@ void __init sve_init_vq_map(void) /* * If we haven't committed to the set of supported VQs yet, filter out * those not supported by the current CPU. + * This function is called during the bring-up of early secondary CPUs only. */ void sve_update_vq_map(void) {
@@ -666,7 +671,10 @@ void sve_update_vq_map(void) bitmap_or(sve_vq_partial_map, sve_vq_partial_map, tmp_map, SVE_VQ_MAX); } -/* Check whether the current CPU supports all VQs in the committed set */ +/* + * Check whether the current CPU supports all VQs in the committed set. + * This function is called during the bring-up of late secondary CPUs only. + */ int sve_verify_vq_map(void) { DECLARE_BITMAP(tmp_map, SVE_VQ_MAX);
--
2.1.4
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