LXR linux/arch/arm64/include/asm/fpsimd.h

   1/*
   2 * Copyright (C) 2012 ARM Ltd.
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 * GNU General Public License for more details.
  12 *
  13 * You should have received a copy of the GNU General Public License
  14 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15 */
  16#ifndef __ASM_FP_H
  17#define __ASM_FP_H
  18
  19#include <asm/errno.h>
  20#include <asm/ptrace.h>
  21#include <asm/processor.h>
  22#include <asm/sigcontext.h>
  23#include <asm/sysreg.h>
  24
  25#ifndef __ASSEMBLY__
  26
  27#include <linux/bitmap.h>
  28#include <linux/build_bug.h>
  29#include <linux/bug.h>
  30#include <linux/cache.h>
  31#include <linux/init.h>
  32#include <linux/stddef.h>
  33#include <linux/types.h>
  34
  35#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
  36/* Masks for extracting the FPSR and FPCR from the FPSCR */
  37#define VFP_FPSCR_STAT_MASK     0xf800009f
  38#define VFP_FPSCR_CTRL_MASK     0x07f79f00
  39/*
  40 * The VFP state has 32x64-bit registers and a single 32-bit
  41 * control/status register.
  42 */
  43#define VFP_STATE_SIZE          ((32 * 8) + 4)
  44#endif
  45
  46struct task_struct;
  47
  48extern void fpsimd_save_state(struct user_fpsimd_state *state);
  49extern void fpsimd_load_state(struct user_fpsimd_state *state);
  50
  51extern void fpsimd_thread_switch(struct task_struct *next);
  52extern void fpsimd_flush_thread(void);
  53
  54extern void fpsimd_signal_preserve_current_state(void);
  55extern void fpsimd_preserve_current_state(void);
  56extern void fpsimd_restore_current_state(void);
  57extern void fpsimd_update_current_state(struct user_fpsimd_state const *state);
  58
  59extern void fpsimd_bind_task_to_cpu(void);
  60extern void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *state,
  61                                     void *sve_state, unsigned int sve_vl);
  62
  63extern void fpsimd_flush_task_state(struct task_struct *target);
  64extern void fpsimd_save_and_flush_cpu_state(void);
  65
  66/* Maximum VL that SVE VL-agnostic software can transparently support */
  67#define SVE_VL_ARCH_MAX 0x100
  68
  69/* Offset of FFR in the SVE register dump */
  70static inline size_t sve_ffr_offset(int vl)
  71{
  72        return SVE_SIG_FFR_OFFSET(sve_vq_from_vl(vl)) - SVE_SIG_REGS_OFFSET;
  73}
  74
  75static inline void *sve_pffr(struct thread_struct *thread)
  76{
  77        return (char *)thread->sve_state + sve_ffr_offset(thread->sve_vl);
  78}
  79
  80extern void sve_save_state(void *state, u32 *pfpsr);
  81extern void sve_load_state(void const *state, u32 const *pfpsr,
  82                           unsigned long vq_minus_1);
  83extern unsigned int sve_get_vl(void);
  84
  85struct arm64_cpu_capabilities;
  86extern void sve_kernel_enable(const struct arm64_cpu_capabilities *__unused);
  87
  88extern u64 read_zcr_features(void);
  89
  90extern int __ro_after_init sve_max_vl;
  91extern int __ro_after_init sve_max_virtualisable_vl;
  92extern __ro_after_init DECLARE_BITMAP(sve_vq_map, SVE_VQ_MAX);
  93
  94/*
  95 * Helpers to translate bit indices in sve_vq_map to VQ values (and
  96 * vice versa).  This allows find_next_bit() to be used to find the
  97 * _maximum_ VQ not exceeding a certain value.
  98 */
  99static inline unsigned int __vq_to_bit(unsigned int vq)
 100{
 101        return SVE_VQ_MAX - vq;
 102}
 103
 104static inline unsigned int __bit_to_vq(unsigned int bit)
 105{
 106        return SVE_VQ_MAX - bit;
 107}
 108
 109/* Ensure vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX before calling this function */
 110static inline bool sve_vq_available(unsigned int vq)
 111{
 112        return test_bit(__vq_to_bit(vq), sve_vq_map);
 113}
 114
 115#ifdef CONFIG_ARM64_SVE
 116
 117extern size_t sve_state_size(struct task_struct const *task);
 118
 119extern void sve_alloc(struct task_struct *task);
 120extern void fpsimd_release_task(struct task_struct *task);
 121extern void fpsimd_sync_to_sve(struct task_struct *task);
 122extern void sve_sync_to_fpsimd(struct task_struct *task);
 123extern void sve_sync_from_fpsimd_zeropad(struct task_struct *task);
 124
 125extern int sve_set_vector_length(struct task_struct *task,
 126                                 unsigned long vl, unsigned long flags);
 127
 128extern int sve_set_current_vl(unsigned long arg);
 129extern int sve_get_current_vl(void);
 130
 131static inline void sve_user_disable(void)
 132{
 133        sysreg_clear_set(cpacr_el1, CPACR_EL1_ZEN_EL0EN, 0);
 134}
 135
 136static inline void sve_user_enable(void)
 137{
 138        sysreg_clear_set(cpacr_el1, 0, CPACR_EL1_ZEN_EL0EN);
 139}
 140
 141/*
 142 * Probing and setup functions.
 143 * Calls to these functions must be serialised with one another.
 144 */
 145extern void __init sve_init_vq_map(void);
 146extern void sve_update_vq_map(void);
 147extern int sve_verify_vq_map(void);
 148extern void __init sve_setup(void);
 149
 150#else /* ! CONFIG_ARM64_SVE */
 151
 152static inline void sve_alloc(struct task_struct *task) { }
 153static inline void fpsimd_release_task(struct task_struct *task) { }
 154static inline void sve_sync_to_fpsimd(struct task_struct *task) { }
 155static inline void sve_sync_from_fpsimd_zeropad(struct task_struct *task) { }
 156
 157static inline int sve_set_current_vl(unsigned long arg)
 158{
 159        return -EINVAL;
 160}
 161
 162static inline int sve_get_current_vl(void)
 163{
 164        return -EINVAL;
 165}
 166
 167static inline void sve_user_disable(void) { BUILD_BUG(); }
 168static inline void sve_user_enable(void) { BUILD_BUG(); }
 169
 170static inline void sve_init_vq_map(void) { }
 171static inline void sve_update_vq_map(void) { }
 172static inline int sve_verify_vq_map(void) { return 0; }
 173static inline void sve_setup(void) { }
 174
 175#endif /* ! CONFIG_ARM64_SVE */
 176
 177/* For use by EFI runtime services calls only */
 178extern void __efi_fpsimd_begin(void);
 179extern void __efi_fpsimd_end(void);
 180
 181#endif
 182
 183#endif
 184