From: Mark Rutland <mark.rutland@arm•com>
To: linux-arm-kernel@lists•infradead.org, kvmarm@lists•linux.dev
Cc: broonie@kernel•org, catalin.marinas@arm•com, james.morse@arm•com,
mark.rutland@arm•com, maz@kernel•org, oupton@kernel•org,
tabba@google•com, vladimir.murzin@arm•com, will@kernel•org
Subject: [PATCH v3 14/18] arm64: fpsimd: Use opaque type for SME state
Date: Tue, 2 Jun 2026 16:11:46 +0100 [thread overview]
Message-ID: <20260602151150.925126-15-mark.rutland@arm.com> (raw)
In-Reply-To: <20260602151150.925126-1-mark.rutland@arm.com>
As the SME state size can vary at runtime, we don't have a concrete type
for the in-memory SME state, and pass this around using a pointer to
void.
Using pointer to void means that it's very easy to introduce errors that
cannot be caught by the compiler (e.g. as 'void **' can be assigned to
'void *').
Improve this by adding an opaque 'struct arm64_sme_state', and
consistently passing a pointer to this.
Signed-off-by: Mark Rutland <mark.rutland@arm•com>
Reviewed-by: Mark Brown <broonie@kernel•org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm•com>
Cc: Catalin Marinas <catalin.marinas@arm•com>
Cc: Fuad Tabba <tabba@google•com>
Cc: James Morse <james.morse@arm•com>
Cc: Marc Zyngier <maz@kernel•org>
Cc: Oliver Upton <oupton@kernel•org>
Cc: Will Deacon <will@kernel•org>
---
arch/arm64/include/asm/fpsimd.h | 8 ++++----
arch/arm64/include/asm/processor.h | 3 ++-
arch/arm64/kernel/fpsimd.c | 4 ++--
3 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
index 581661a759a3f..fff6d54afd9fe 100644
--- a/arch/arm64/include/asm/fpsimd.h
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -163,7 +163,7 @@ extern void fpsimd_update_current_state(struct user_fpsimd_state const *state);
struct cpu_fp_state {
struct user_fpsimd_state *st;
struct arm64_sve_state *sve_state;
- void *sme_state;
+ struct arm64_sme_state *sme_state;
u64 *svcr;
u64 *fpmr;
unsigned int sve_vl;
@@ -199,7 +199,7 @@ static inline void *thread_zt_state(struct thread_struct *thread)
{
/* The ZT register state is stored immediately after the ZA state */
unsigned int sme_vq = sve_vq_from_vl(thread_get_sme_vl(thread));
- return thread->sme_state + ZA_SIG_REGS_SIZE(sme_vq);
+ return (void *)thread->sme_state + ZA_SIG_REGS_SIZE(sme_vq);
}
static inline unsigned int sve_get_vl(void)
@@ -218,8 +218,8 @@ static inline unsigned int sve_get_vl(void)
extern void sve_save_state(struct arm64_sve_state *state, int save_ffr);
extern void sve_load_state(const struct arm64_sve_state *state, int restore_ffr);
extern void sve_flush_live(bool flush_ffr, unsigned long vq_minus_1);
-extern void sme_save_state(void *state, int zt);
-extern void sme_load_state(void const *state, int zt);
+extern void sme_save_state(struct arm64_sme_state *state, int zt);
+extern void sme_load_state(const struct arm64_sme_state *state, int zt);
struct arm64_cpu_capabilities;
extern void cpu_enable_fpsimd(const struct arm64_cpu_capabilities *__unused);
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index 96c0c30eac50f..c2a627f393144 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -131,6 +131,7 @@ enum fp_type {
};
struct arm64_sve_state; /* Opaque type */
+struct arm64_sme_state; /* Opaque type */
struct cpu_context {
unsigned long x19;
@@ -167,7 +168,7 @@ struct thread_struct {
enum fp_type fp_type; /* registers FPSIMD or SVE? */
unsigned int fpsimd_cpu;
struct arm64_sve_state *sve_state; /* SVE registers, if any */
- void *sme_state; /* ZA and ZT state, if any */
+ struct arm64_sme_state *sme_state; /* ZA and ZT state, if any */
unsigned int vl[ARM64_VEC_MAX]; /* vector length */
unsigned int vl_onexec[ARM64_VEC_MAX]; /* vl after next exec */
unsigned long fault_address; /* fault info */
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 0da2f75de5dde..b9506422d29c6 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -808,7 +808,7 @@ static int change_live_vector_length(struct task_struct *task,
unsigned int sve_vl = task_get_sve_vl(task);
unsigned int sme_vl = task_get_sme_vl(task);
struct arm64_sve_state *sve_state = NULL;
- void *sme_state = NULL;
+ struct arm64_sme_state *sme_state = NULL;
if (type == ARM64_VEC_SME)
sme_vl = vl;
@@ -1645,7 +1645,7 @@ static void fpsimd_flush_thread_vl(enum vec_type type)
void fpsimd_flush_thread(void)
{
struct arm64_sve_state *sve_state = NULL;
- void *sme_state = NULL;
+ struct arm64_sme_state *sme_state = NULL;
if (!system_supports_fpsimd())
return;
--
2.30.2
next prev parent reply other threads:[~2026-06-02 15:12 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-02 15:11 [PATCH v3 00/18] arm64+KVM: FPSIMD/SVE/SME cleanups Mark Rutland
2026-06-02 15:11 ` [PATCH v3 01/18] KVM: arm64: Don't include <asm/fpsimdmacros.h> Mark Rutland
2026-06-02 15:11 ` [PATCH v3 02/18] KVM: arm64: Don't override FFR save/restore argument Mark Rutland
2026-06-02 15:36 ` Mark Brown
2026-06-03 9:25 ` Mark Rutland
2026-06-02 15:11 ` [PATCH v3 03/18] KVM: arm64: pkvm: Save host FPMR in host cpu context Mark Rutland
2026-06-02 15:11 ` [PATCH v3 04/18] KVM: arm64: pkvm: Remove struct cpu_sve_state Mark Rutland
2026-06-02 15:11 ` [PATCH v3 05/18] arm64: fpsimd: Fold sve_init_regs() into do_sve_acc() Mark Rutland
2026-06-02 15:11 ` [PATCH v3 06/18] arm64: fpsimd: Remove sve_set_vq() and sme_set_vq() Mark Rutland
2026-06-02 15:11 ` [PATCH v3 07/18] arm64: fpsimd: Use assembler for SVE instructions Mark Rutland
2026-06-02 15:11 ` [PATCH v3 08/18] arm64: fpsimd: Use assembler for baseline SME instructions Mark Rutland
2026-06-02 15:11 ` [PATCH v3 09/18] arm64: fpsimd: Move sve_get_vl() and sme_get_vl() inline Mark Rutland
2026-06-02 15:11 ` [PATCH v3 10/18] arm64: sysreg: Add FPCR and FPSR Mark Rutland
2026-06-02 15:11 ` [PATCH v3 11/18] arm64: fpsimd: Split FPSR/FPCR from SVE save/restore Mark Rutland
2026-06-02 15:11 ` [PATCH v3 12/18] arm64: fpsimd: Move fpsimd save/restore inline Mark Rutland
2026-06-02 15:11 ` [PATCH v3 13/18] arm64: fpsimd: Use opaque type for SVE state Mark Rutland
2026-06-02 15:11 ` Mark Rutland [this message]
2026-06-02 15:11 ` [PATCH v3 15/18] arm64: fpsimd: Move SVE save/restore inline Mark Rutland
2026-06-02 15:11 ` [PATCH v3 16/18] arm64: fpsimd: Move sve_flush_live() inline Mark Rutland
2026-06-02 15:11 ` [PATCH v3 17/18] arm64: fpsimd: Move SME save/restore inline Mark Rutland
2026-06-02 15:30 ` Mark Brown
2026-06-02 15:11 ` [PATCH v3 18/18] arm64: fpsimd: Remove <asm/fpsimdmacros.h> Mark Rutland
2026-06-02 15:33 ` Mark Brown
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