1 files changed, 412 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
new file mode 100644
index 000000000..8df46f186
--- /dev/null
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -0,0 +1,412 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ */
+#ifndef __ASM_FP_H
+#define __ASM_FP_H
+
+#include <asm/errno.h>
+#include <asm/ptrace.h>
+#include <asm/processor.h>
+#include <asm/sigcontext.h>
+#include <asm/sysreg.h>
+
+#ifndef __ASSEMBLY__
+
+#include <linux/bitmap.h>
+#include <linux/build_bug.h>
+#include <linux/bug.h>
+#include <linux/cache.h>
+#include <linux/init.h>
+#include <linux/stddef.h>
+#include <linux/types.h>
+
+#ifdef CONFIG_COMPAT
+/* Masks for extracting the FPSR and FPCR from the FPSCR */
+#define VFP_FPSCR_STAT_MASK	0xf800009f
+#define VFP_FPSCR_CTRL_MASK	0x07f79f00
+/*
+ * The VFP state has 32x64-bit registers and a single 32-bit
+ * control/status register.
+ */
+#define VFP_STATE_SIZE		((32 * 8) + 4)
+#endif
+
+/*
+ * When we defined the maximum SVE vector length we defined the ABI so
+ * that the maximum vector length included all the reserved for future
+ * expansion bits in ZCR rather than those just currently defined by
+ * the architecture. While SME follows a similar pattern the fact that
+ * it includes a square matrix means that any allocations that attempt
+ * to cover the maximum potential vector length (such as happen with
+ * the regset used for ptrace) end up being extremely large. Define
+ * the much lower actual limit for use in such situations.
+ */
+#define SME_VQ_MAX	16
+
+struct task_struct;
+
+extern void fpsimd_save_state(struct user_fpsimd_state *state);
+extern void fpsimd_load_state(struct user_fpsimd_state *state);
+
+extern void fpsimd_thread_switch(struct task_struct *next);
+extern void fpsimd_flush_thread(void);
+
+extern void fpsimd_signal_preserve_current_state(void);
+extern void fpsimd_preserve_current_state(void);
+extern void fpsimd_restore_current_state(void);
+extern void fpsimd_update_current_state(struct user_fpsimd_state const *state);
+extern void fpsimd_kvm_prepare(void);
+
+struct cpu_fp_state {
+	struct user_fpsimd_state *st;
+	void *sve_state;
+	void *sme_state;
+	u64 *svcr;
+	unsigned int sve_vl;
+	unsigned int sme_vl;
+	enum fp_type *fp_type;
+	enum fp_type to_save;
+};
+
+extern void fpsimd_bind_state_to_cpu(struct cpu_fp_state *fp_state);
+
+extern void fpsimd_flush_task_state(struct task_struct *target);
+extern void fpsimd_save_and_flush_cpu_state(void);
+
+static inline bool thread_sm_enabled(struct thread_struct *thread)
+{
+	return system_supports_sme() && (thread->svcr & SVCR_SM_MASK);
+}
+
+static inline bool thread_za_enabled(struct thread_struct *thread)
+{
+	return system_supports_sme() && (thread->svcr & SVCR_ZA_MASK);
+}
+
+/* Maximum VL that SVE/SME VL-agnostic software can transparently support */
+#define VL_ARCH_MAX 0x100
+
+/* Offset of FFR in the SVE register dump */
+static inline size_t sve_ffr_offset(int vl)
+{
+	return SVE_SIG_FFR_OFFSET(sve_vq_from_vl(vl)) - SVE_SIG_REGS_OFFSET;
+}
+
+static inline void *sve_pffr(struct thread_struct *thread)
+{
+	unsigned int vl;
+
+	if (system_supports_sme() && thread_sm_enabled(thread))
+		vl = thread_get_sme_vl(thread);
+	else
+		vl = thread_get_sve_vl(thread);
+
+	return (char *)thread->sve_state + sve_ffr_offset(vl);
+}
+
+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);
+}
+
+extern void sve_save_state(void *state, u32 *pfpsr, int save_ffr);
+extern void sve_load_state(void const *state, u32 const *pfpsr,
+			   int restore_ffr);
+extern void sve_flush_live(bool flush_ffr, unsigned long vq_minus_1);
+extern unsigned int sve_get_vl(void);
+extern void sve_set_vq(unsigned long vq_minus_1);
+extern void sme_set_vq(unsigned long vq_minus_1);
+extern void sme_save_state(void *state, int zt);
+extern void sme_load_state(void const *state, int zt);
+
+struct arm64_cpu_capabilities;
+extern void sve_kernel_enable(const struct arm64_cpu_capabilities *__unused);
+extern void sme_kernel_enable(const struct arm64_cpu_capabilities *__unused);
+extern void sme2_kernel_enable(const struct arm64_cpu_capabilities *__unused);
+extern void fa64_kernel_enable(const struct arm64_cpu_capabilities *__unused);
+
+extern u64 read_zcr_features(void);
+extern u64 read_smcr_features(void);
+
+/*
+ * Helpers to translate bit indices in sve_vq_map to VQ values (and
+ * vice versa).  This allows find_next_bit() to be used to find the
+ * _maximum_ VQ not exceeding a certain value.
+ */
+static inline unsigned int __vq_to_bit(unsigned int vq)
+{
+	return SVE_VQ_MAX - vq;
+}
+
+static inline unsigned int __bit_to_vq(unsigned int bit)
+{
+	return SVE_VQ_MAX - bit;
+}
+
+
+struct vl_info {
+	enum vec_type type;
+	const char *name;		/* For display purposes */
+
+	/* Minimum supported vector length across all CPUs */
+	int min_vl;
+
+	/* Maximum supported vector length across all CPUs */
+	int max_vl;
+	int max_virtualisable_vl;
+
+	/*
+	 * Set of available vector lengths,
+	 * where length vq encoded as bit __vq_to_bit(vq):
+	 */
+	DECLARE_BITMAP(vq_map, SVE_VQ_MAX);
+
+	/* Set of vector lengths present on at least one cpu: */
+	DECLARE_BITMAP(vq_partial_map, SVE_VQ_MAX);
+};
+
+#ifdef CONFIG_ARM64_SVE
+
+extern void sve_alloc(struct task_struct *task, bool flush);
+extern void fpsimd_release_task(struct task_struct *task);
+extern void fpsimd_sync_to_sve(struct task_struct *task);
+extern void fpsimd_force_sync_to_sve(struct task_struct *task);
+extern void sve_sync_to_fpsimd(struct task_struct *task);
+extern void sve_sync_from_fpsimd_zeropad(struct task_struct *task);
+
+extern int vec_set_vector_length(struct task_struct *task, enum vec_type type,
+				 unsigned long vl, unsigned long flags);
+
+extern int sve_set_current_vl(unsigned long arg);
+extern int sve_get_current_vl(void);
+
+static inline void sve_user_disable(void)
+{
+	sysreg_clear_set(cpacr_el1, CPACR_EL1_ZEN_EL0EN, 0);
+}
+
+static inline void sve_user_enable(void)
+{
+	sysreg_clear_set(cpacr_el1, 0, CPACR_EL1_ZEN_EL0EN);
+}
+
+#define sve_cond_update_zcr_vq(val, reg)		\
+	do {						\
+		u64 __zcr = read_sysreg_s((reg));	\
+		u64 __new = __zcr & ~ZCR_ELx_LEN_MASK;	\
+		__new |= (val) & ZCR_ELx_LEN_MASK;	\
+		if (__zcr != __new)			\
+			write_sysreg_s(__new, (reg));	\
+	} while (0)
+
+/*
+ * Probing and setup functions.
+ * Calls to these functions must be serialised with one another.
+ */
+enum vec_type;
+
+extern void __init vec_init_vq_map(enum vec_type type);
+extern void vec_update_vq_map(enum vec_type type);
+extern int vec_verify_vq_map(enum vec_type type);
+extern void __init sve_setup(void);
+
+extern __ro_after_init struct vl_info vl_info[ARM64_VEC_MAX];
+
+static inline void write_vl(enum vec_type type, u64 val)
+{
+	u64 tmp;
+
+	switch (type) {
+#ifdef CONFIG_ARM64_SVE
+	case ARM64_VEC_SVE:
+		tmp = read_sysreg_s(SYS_ZCR_EL1) & ~ZCR_ELx_LEN_MASK;
+		write_sysreg_s(tmp | val, SYS_ZCR_EL1);
+		break;
+#endif
+#ifdef CONFIG_ARM64_SME
+	case ARM64_VEC_SME:
+		tmp = read_sysreg_s(SYS_SMCR_EL1) & ~SMCR_ELx_LEN_MASK;
+		write_sysreg_s(tmp | val, SYS_SMCR_EL1);
+		break;
+#endif
+	default:
+		WARN_ON_ONCE(1);
+		break;
+	}
+}
+
+static inline int vec_max_vl(enum vec_type type)
+{
+	return vl_info[type].max_vl;
+}
+
+static inline int vec_max_virtualisable_vl(enum vec_type type)
+{
+	return vl_info[type].max_virtualisable_vl;
+}
+
+static inline int sve_max_vl(void)
+{
+	return vec_max_vl(ARM64_VEC_SVE);
+}
+
+static inline int sve_max_virtualisable_vl(void)
+{
+	return vec_max_virtualisable_vl(ARM64_VEC_SVE);
+}
+
+/* Ensure vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX before calling this function */
+static inline bool vq_available(enum vec_type type, unsigned int vq)
+{
+	return test_bit(__vq_to_bit(vq), vl_info[type].vq_map);
+}
+
+static inline bool sve_vq_available(unsigned int vq)
+{
+	return vq_available(ARM64_VEC_SVE, vq);
+}
+
+size_t sve_state_size(struct task_struct const *task);
+
+#else /* ! CONFIG_ARM64_SVE */
+
+static inline void sve_alloc(struct task_struct *task, bool flush) { }
+static inline void fpsimd_release_task(struct task_struct *task) { }
+static inline void sve_sync_to_fpsimd(struct task_struct *task) { }
+static inline void sve_sync_from_fpsimd_zeropad(struct task_struct *task) { }
+
+static inline int sve_max_virtualisable_vl(void)
+{
+	return 0;
+}
+
+static inline int sve_set_current_vl(unsigned long arg)
+{
+	return -EINVAL;
+}
+
+static inline int sve_get_current_vl(void)
+{
+	return -EINVAL;
+}
+
+static inline int sve_max_vl(void)
+{
+	return -EINVAL;
+}
+
+static inline bool sve_vq_available(unsigned int vq) { return false; }
+
+static inline void sve_user_disable(void) { BUILD_BUG(); }
+static inline void sve_user_enable(void) { BUILD_BUG(); }
+
+#define sve_cond_update_zcr_vq(val, reg) do { } while (0)
+
+static inline void vec_init_vq_map(enum vec_type t) { }
+static inline void vec_update_vq_map(enum vec_type t) { }
+static inline int vec_verify_vq_map(enum vec_type t) { return 0; }
+static inline void sve_setup(void) { }
+
+static inline size_t sve_state_size(struct task_struct const *task)
+{
+	return 0;
+}
+
+#endif /* ! CONFIG_ARM64_SVE */
+
+#ifdef CONFIG_ARM64_SME
+
+static inline void sme_user_disable(void)
+{
+	sysreg_clear_set(cpacr_el1, CPACR_EL1_SMEN_EL0EN, 0);
+}
+
+static inline void sme_user_enable(void)
+{
+	sysreg_clear_set(cpacr_el1, 0, CPACR_EL1_SMEN_EL0EN);
+}
+
+static inline void sme_smstart_sm(void)
+{
+	asm volatile(__msr_s(SYS_SVCR_SMSTART_SM_EL0, "xzr"));
+}
+
+static inline void sme_smstop_sm(void)
+{
+	asm volatile(__msr_s(SYS_SVCR_SMSTOP_SM_EL0, "xzr"));
+}
+
+static inline void sme_smstop(void)
+{
+	asm volatile(__msr_s(SYS_SVCR_SMSTOP_SMZA_EL0, "xzr"));
+}
+
+extern void __init sme_setup(void);
+
+static inline int sme_max_vl(void)
+{
+	return vec_max_vl(ARM64_VEC_SME);
+}
+
+static inline int sme_max_virtualisable_vl(void)
+{
+	return vec_max_virtualisable_vl(ARM64_VEC_SME);
+}
+
+extern void sme_alloc(struct task_struct *task, bool flush);
+extern unsigned int sme_get_vl(void);
+extern int sme_set_current_vl(unsigned long arg);
+extern int sme_get_current_vl(void);
+
+/*
+ * Return how many bytes of memory are required to store the full SME
+ * specific state for task, given task's currently configured vector
+ * length.
+ */
+static inline size_t sme_state_size(struct task_struct const *task)
+{
+	unsigned int vl = task_get_sme_vl(task);
+	size_t size;
+
+	size = ZA_SIG_REGS_SIZE(sve_vq_from_vl(vl));
+
+	if (system_supports_sme2())
+		size += ZT_SIG_REG_SIZE;
+
+	return size;
+}
+
+#else
+
+static inline void sme_user_disable(void) { BUILD_BUG(); }
+static inline void sme_user_enable(void) { BUILD_BUG(); }
+
+static inline void sme_smstart_sm(void) { }
+static inline void sme_smstop_sm(void) { }
+static inline void sme_smstop(void) { }
+
+static inline void sme_alloc(struct task_struct *task, bool flush) { }
+static inline void sme_setup(void) { }
+static inline unsigned int sme_get_vl(void) { return 0; }
+static inline int sme_max_vl(void) { return 0; }
+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 sme_state_size(struct task_struct const *task)
+{
+	return 0;
+}
+
+#endif /* ! CONFIG_ARM64_SME */
+
+/* For use by EFI runtime services calls only */
+extern void __efi_fpsimd_begin(void);
+extern void __efi_fpsimd_end(void);
+
+#endif
+
+#endif