[PATCH v4 01/21] arm64/sme: Rename za_state to sme_state

From: Mark Brown
Date: Mon Jan 16 2023 - 11:07:46 EST

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In preparation for adding support for storage for ZT0 to the thread_struct
rename za_state to sme_state. Since ZT0 is accessible when PSTATE.ZA is
set just like ZA itself we will extend the allocation done for ZA to
cover it, avoiding the need to further expand task_struct for non-SME
tasks.

No functional changes.

Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
arch/arm64/include/asm/fpsimd.h | 15 +++++++++------
arch/arm64/include/asm/processor.h | 2 +-
arch/arm64/kernel/fpsimd.c | 34 +++++++++++++++++-----------------
arch/arm64/kernel/process.c | 13 +++++++------
arch/arm64/kernel/ptrace.c | 6 +++---
arch/arm64/kernel/signal.c | 8 ++++----
arch/arm64/kvm/fpsimd.c | 2 +-
7 files changed, 42 insertions(+), 38 deletions(-)

diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
index e6fa1e2982c8..2d3fa80cd95d 100644
--- a/arch/arm64/include/asm/fpsimd.h
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -61,7 +61,7 @@ extern void fpsimd_kvm_prepare(void);
struct cpu_fp_state {
struct user_fpsimd_state *st;
void *sve_state;
- void *za_state;
+ void *sme_state;
u64 *svcr;
unsigned int sve_vl;
unsigned int sme_vl;
@@ -355,14 +355,17 @@ extern int sme_get_current_vl(void);

/*
* Return how many bytes of memory are required to store the full SME
- * specific state (currently just ZA) for task, given task's currently
- * configured vector length.
+ * specific state for task, given task's currently configured vector
+ * length.
*/
-static inline size_t za_state_size(struct task_struct const *task)
+static inline size_t sme_state_size(struct task_struct const *task)
{
unsigned int vl = task_get_sme_vl(task);
+ size_t size;

- return ZA_SIG_REGS_SIZE(sve_vq_from_vl(vl));
+ size = ZA_SIG_REGS_SIZE(sve_vq_from_vl(vl));
+
+ return size;
}

#else
@@ -382,7 +385,7 @@ static inline int sme_max_virtualisable_vl(void) { return 0; }
static inline int sme_set_current_vl(unsigned long arg) { return -EINVAL; }
static inline int sme_get_current_vl(void) { return -EINVAL; }

-static inline size_t za_state_size(struct task_struct const *task)
+static inline size_t sme_state_size(struct task_struct const *task)
{
return 0;
}
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index d51b32a69309..3918f2a67970 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -161,7 +161,7 @@ struct thread_struct {
enum fp_type fp_type; /* registers FPSIMD or SVE? */
unsigned int fpsimd_cpu;
void *sve_state; /* SVE registers, if any */
- void *za_state; /* ZA register, if any */
+ void *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 dcc81e7200d4..9e168a9eb615 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -299,7 +299,7 @@ void task_set_vl_onexec(struct task_struct *task, enum vec_type type,
/*
* TIF_SME controls whether a task can use SME without trapping while
* in userspace, when TIF_SME is set then we must have storage
- * alocated in sve_state and za_state to store the contents of both ZA
+ * alocated in sve_state and sme_state to store the contents of both ZA
* and the SVE registers for both streaming and non-streaming modes.
*
* If both SVCR.ZA and SVCR.SM are disabled then at any point we
@@ -429,7 +429,7 @@ static void task_fpsimd_load(void)
write_sysreg_s(current->thread.svcr, SYS_SVCR);

if (thread_za_enabled(&current->thread))
- za_load_state(current->thread.za_state);
+ za_load_state(current->thread.sme_state);

if (thread_sm_enabled(&current->thread))
restore_ffr = system_supports_fa64();
@@ -490,7 +490,7 @@ static void fpsimd_save(void)
*svcr = read_sysreg_s(SYS_SVCR);

if (*svcr & SVCR_ZA_MASK)
- za_save_state(last->za_state);
+ za_save_state(last->sme_state);

/* If we are in streaming mode override regular SVE. */
if (*svcr & SVCR_SM_MASK) {
@@ -1257,30 +1257,30 @@ void fpsimd_release_task(struct task_struct *dead_task)
#ifdef CONFIG_ARM64_SME

/*
- * Ensure that task->thread.za_state is allocated and sufficiently large.
+ * Ensure that task->thread.sme_state is allocated and sufficiently large.
*
* This function should be used only in preparation for replacing
- * task->thread.za_state with new data. The memory is always zeroed
+ * task->thread.sme_state with new data. The memory is always zeroed
* here to prevent stale data from showing through: this is done in
* the interest of testability and predictability, the architecture
* guarantees that when ZA is enabled it will be zeroed.
*/
void sme_alloc(struct task_struct *task)
{
- if (task->thread.za_state) {
- memset(task->thread.za_state, 0, za_state_size(task));
+ if (task->thread.sme_state) {
+ memset(task->thread.sme_state, 0, sme_state_size(task));
return;
}

/* This could potentially be up to 64K. */
- task->thread.za_state =
- kzalloc(za_state_size(task), GFP_KERNEL);
+ task->thread.sme_state =
+ kzalloc(sme_state_size(task), GFP_KERNEL);
}

static void sme_free(struct task_struct *task)
{
- kfree(task->thread.za_state);
- task->thread.za_state = NULL;
+ kfree(task->thread.sme_state);
+ task->thread.sme_state = NULL;
}

void sme_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p)
@@ -1488,7 +1488,7 @@ void do_sme_acc(unsigned long esr, struct pt_regs *regs)

sve_alloc(current, false);
sme_alloc(current);
- if (!current->thread.sve_state || !current->thread.za_state) {
+ if (!current->thread.sve_state || !current->thread.sme_state) {
force_sig(SIGKILL);
return;
}
@@ -1609,7 +1609,7 @@ static void fpsimd_flush_thread_vl(enum vec_type type)
void fpsimd_flush_thread(void)
{
void *sve_state = NULL;
- void *za_state = NULL;
+ void *sme_state = NULL;

if (!system_supports_fpsimd())
return;
@@ -1634,8 +1634,8 @@ void fpsimd_flush_thread(void)
clear_thread_flag(TIF_SME);

/* Defer kfree() while in atomic context */
- za_state = current->thread.za_state;
- current->thread.za_state = NULL;
+ sme_state = current->thread.sme_state;
+ current->thread.sme_state = NULL;

fpsimd_flush_thread_vl(ARM64_VEC_SME);
current->thread.svcr = 0;
@@ -1645,7 +1645,7 @@ void fpsimd_flush_thread(void)

put_cpu_fpsimd_context();
kfree(sve_state);
- kfree(za_state);
+ kfree(sme_state);
}

/*
@@ -1711,7 +1711,7 @@ static void fpsimd_bind_task_to_cpu(void)
WARN_ON(!system_supports_fpsimd());
last->st = &current->thread.uw.fpsimd_state;
last->sve_state = current->thread.sve_state;
- last->za_state = current->thread.za_state;
+ last->sme_state = current->thread.sme_state;
last->sve_vl = task_get_sve_vl(current);
last->sme_vl = task_get_sme_vl(current);
last->svcr = &current->thread.svcr;
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 269ac1c25ae2..4ce0c4313ec6 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -311,23 +311,24 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
* This may be shortly freed if we exec() or if CLONE_SETTLS
* but it's simpler to do it here. To avoid confusing the rest
* of the code ensure that we have a sve_state allocated
- * whenever za_state is allocated.
+ * whenever sme_state is allocated.
*/
if (thread_za_enabled(&src->thread)) {
dst->thread.sve_state = kzalloc(sve_state_size(src),
GFP_KERNEL);
if (!dst->thread.sve_state)
return -ENOMEM;
- dst->thread.za_state = kmemdup(src->thread.za_state,
- za_state_size(src),
- GFP_KERNEL);
- if (!dst->thread.za_state) {
+
+ dst->thread.sme_state = kmemdup(src->thread.sme_state,
+ sme_state_size(src),
+ GFP_KERNEL);
+ if (!dst->thread.sme_state) {
kfree(dst->thread.sve_state);
dst->thread.sve_state = NULL;
return -ENOMEM;
}
} else {
- dst->thread.za_state = NULL;
+ dst->thread.sme_state = NULL;
clear_tsk_thread_flag(dst, TIF_SME);
}

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 2686ab157601..67256e7772e4 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -1045,7 +1045,7 @@ static int za_get(struct task_struct *target,
if (thread_za_enabled(&target->thread)) {
start = end;
end = ZA_PT_SIZE(vq);
- membuf_write(&to, target->thread.za_state, end - start);
+ membuf_write(&to, target->thread.sme_state, end - start);
}

/* Zero any trailing padding */
@@ -1099,7 +1099,7 @@ static int za_set(struct task_struct *target,

/* Allocate/reinit ZA storage */
sme_alloc(target);
- if (!target->thread.za_state) {
+ if (!target->thread.sme_state) {
ret = -ENOMEM;
goto out;
}
@@ -1124,7 +1124,7 @@ static int za_set(struct task_struct *target,
start = ZA_PT_ZA_OFFSET;
end = ZA_PT_SIZE(vq);
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
- target->thread.za_state,
+ target->thread.sme_state,
start, end);
if (ret)
goto out;
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index e0d09bf5b01b..27768809dd3e 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -389,7 +389,7 @@ static int preserve_za_context(struct za_context __user *ctx)
* fpsimd_signal_preserve_current_state().
*/
err |= __copy_to_user((char __user *)ctx + ZA_SIG_REGS_OFFSET,
- current->thread.za_state,
+ current->thread.sme_state,
ZA_SIG_REGS_SIZE(vq));
}

@@ -420,7 +420,7 @@ static int restore_za_context(struct user_ctxs *user)

/*
* Careful: we are about __copy_from_user() directly into
- * thread.za_state with preemption enabled, so protection is
+ * thread.sme_state with preemption enabled, so protection is
* needed to prevent a racing context switch from writing stale
* registers back over the new data.
*/
@@ -429,13 +429,13 @@ static int restore_za_context(struct user_ctxs *user)
/* From now, fpsimd_thread_switch() won't touch thread.sve_state */

sme_alloc(current);
- if (!current->thread.za_state) {
+ if (!current->thread.sme_state) {
current->thread.svcr &= ~SVCR_ZA_MASK;
clear_thread_flag(TIF_SME);
return -ENOMEM;
}

- err = __copy_from_user(current->thread.za_state,
+ err = __copy_from_user(current->thread.sme_state,
(char __user const *)user->za +
ZA_SIG_REGS_OFFSET,
ZA_SIG_REGS_SIZE(vq));
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index 02dd7e9ebd39..235775d0c825 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -143,7 +143,7 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu)
fp_state.st = &vcpu->arch.ctxt.fp_regs;
fp_state.sve_state = vcpu->arch.sve_state;
fp_state.sve_vl = vcpu->arch.sve_max_vl;
- fp_state.za_state = NULL;
+ fp_state.sme_state = NULL;
fp_state.svcr = &vcpu->arch.svcr;
fp_state.fp_type = &vcpu->arch.fp_type;

--
2.34.1

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