diff mbox series

[v4,1/4] arm64/fpsimd: Introduce __bit_to_vl() helper

Message ID 20240704-kvm-arm64-fix-pkvm-sve-vl-v4-1-b6898ab23dc4@kernel.org (mailing list archive)
State New
Headers show
Series KVM: arm64: Fix underallocation of storage for SVE state | expand

Commit Message

Mark Brown July 4, 2024, 5:28 p.m. UTC 
In all cases where we use the existing __bit_to_vq() helper we immediately
convert the result into a VL. Provide and use __bit_to_vl() doing this
directly.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/include/asm/fpsimd.h |  4 ++++
 arch/arm64/kernel/fpsimd.c      | 12 ++++++------
 2 files changed, 10 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
index bc69ac368d73..51c21265b4fa 100644
--- a/arch/arm64/include/asm/fpsimd.h
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -172,6 +172,10 @@  static inline unsigned int __bit_to_vq(unsigned int bit)
 	return SVE_VQ_MAX - bit;
 }
 
+static inline unsigned int __bit_to_vl(unsigned int bit)
+{
+	return sve_vl_from_vq(__bit_to_vq(bit));
+}
 
 struct vl_info {
 	enum vec_type type;
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 82e8a6017382..22542fb81812 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -530,7 +530,7 @@  static unsigned int find_supported_vector_length(enum vec_type type,
 
 	bit = find_next_bit(info->vq_map, SVE_VQ_MAX,
 			    __vq_to_bit(sve_vq_from_vl(vl)));
-	return sve_vl_from_vq(__bit_to_vq(bit));
+	return __bit_to_vl(bit);
 }
 
 #if defined(CONFIG_ARM64_SVE) && defined(CONFIG_SYSCTL)
@@ -1103,7 +1103,7 @@  int vec_verify_vq_map(enum vec_type type)
 	 * Mismatches above sve_max_virtualisable_vl are fine, since
 	 * no guest is allowed to configure ZCR_EL2.LEN to exceed this:
 	 */
-	if (sve_vl_from_vq(__bit_to_vq(b)) <= info->max_virtualisable_vl) {
+	if (__bit_to_vl(b) <= info->max_virtualisable_vl) {
 		pr_warn("%s: cpu%d: Unsupported vector length(s) present\n",
 			info->name, smp_processor_id());
 		return -EINVAL;
@@ -1169,7 +1169,7 @@  void __init sve_setup(void)
 		set_bit(__vq_to_bit(SVE_VQ_MIN), info->vq_map);
 
 	max_bit = find_first_bit(info->vq_map, SVE_VQ_MAX);
-	info->max_vl = sve_vl_from_vq(__bit_to_vq(max_bit));
+	info->max_vl = __bit_to_vl(max_bit);
 
 	/*
 	 * For the default VL, pick the maximum supported value <= 64.
@@ -1188,7 +1188,7 @@  void __init sve_setup(void)
 		/* No virtualisable VLs?  This is architecturally forbidden. */
 		info->max_virtualisable_vl = SVE_VQ_MIN;
 	else /* b + 1 < SVE_VQ_MAX */
-		info->max_virtualisable_vl = sve_vl_from_vq(__bit_to_vq(b + 1));
+		info->max_virtualisable_vl = __bit_to_vl(b + 1);
 
 	if (info->max_virtualisable_vl > info->max_vl)
 		info->max_virtualisable_vl = info->max_vl;
@@ -1305,10 +1305,10 @@  void __init sme_setup(void)
 	WARN_ON(bitmap_empty(info->vq_map, SVE_VQ_MAX));
 
 	min_bit = find_last_bit(info->vq_map, SVE_VQ_MAX);
-	info->min_vl = sve_vl_from_vq(__bit_to_vq(min_bit));
+	info->min_vl = __bit_to_vl(min_bit);
 
 	max_bit = find_first_bit(info->vq_map, SVE_VQ_MAX);
-	info->max_vl = sve_vl_from_vq(__bit_to_vq(max_bit));
+	info->max_vl = __bit_to_vl(max_bit);
 
 	WARN_ON(info->min_vl > info->max_vl);