arch/arc/include/asm/dsp-impl.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2020 Synopsys, Inc. (www.synopsys.com)
   4  *
   5  * Author: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
   6  */
   7 #ifndef __ASM_ARC_DSP_IMPL_H
   8 #define __ASM_ARC_DSP_IMPL_H
   9
  10 #include <asm/dsp.h>
  11
  12 #define DSP_CTRL_DISABLED_ALL           0
  13
  14 #ifdef __ASSEMBLY__
  15
  16 /* clobbers r5 register */
  17 .macro DSP_EARLY_INIT
  18         lr      r5, [ARC_AUX_DSP_BUILD]
  19         bmsk    r5, r5, 7
  20         breq    r5, 0, 1f
  21         mov     r5, DSP_CTRL_DISABLED_ALL
  22         sr      r5, [ARC_AUX_DSP_CTRL]
  23 1:
  24 .endm
  25
  26 /* clobbers r10, r11 registers pair */
  27 .macro DSP_SAVE_REGFILE_IRQ
  28 #if defined(CONFIG_ARC_DSP_KERNEL)
  29         /*
  30          * Drop any changes to DSP_CTRL made by userspace so userspace won't be
  31          * able to break kernel - reset it to DSP_CTRL_DISABLED_ALL value
  32          */
  33         mov     r10, DSP_CTRL_DISABLED_ALL
  34         sr      r10, [ARC_AUX_DSP_CTRL]
  35
  36 #elif defined(CONFIG_ARC_DSP_SAVE_RESTORE_REGS)
  37         /*
  38          * Save DSP_CTRL register and reset it to value suitable for kernel
  39          * (DSP_CTRL_DISABLED_ALL)
  40          */
  41         mov     r10, DSP_CTRL_DISABLED_ALL
  42         aex     r10, [ARC_AUX_DSP_CTRL]
  43         st      r10, [sp, PT_DSP_CTRL]
  44
  45 #endif
  46 .endm
  47
  48 /* clobbers r10, r11 registers pair */
  49 .macro DSP_RESTORE_REGFILE_IRQ
  50 #if defined(CONFIG_ARC_DSP_SAVE_RESTORE_REGS)
  51         ld      r10, [sp, PT_DSP_CTRL]
  52         sr      r10, [ARC_AUX_DSP_CTRL]
  53
  54 #endif
  55 .endm
  56
  57 #else /* __ASEMBLY__ */
  58
  59 #include <linux/sched.h>
  60 #include <asm/asserts.h>
  61 #include <asm/switch_to.h>
  62
  63 #ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
  64
  65 /*
  66  * As we save new and restore old AUX register value in the same place we
  67  * can optimize a bit and use AEX instruction (swap contents of an auxiliary
  68  * register with a core register) instead of LR + SR pair.
  69  */
  70 #define AUX_SAVE_RESTORE(_saveto, _readfrom, _offt, _aux)               \
  71 do {                                                                    \
  72         long unsigned int _scratch;                                     \
  73                                                                         \
  74         __asm__ __volatile__(                                           \
  75                 "ld     %0, [%2, %4]                    \n"             \
  76                 "aex    %0, [%3]                        \n"             \
  77                 "st     %0, [%1, %4]                    \n"             \
  78                 :                                                       \
  79                   "=&r" (_scratch)      /* must be early clobber */     \
  80                 :                                                       \
  81                    "r" (_saveto),                                       \
  82                    "r" (_readfrom),                                     \
  83                    "Ir" (_aux),                                         \
  84                    "Ir" (_offt)                                         \
  85                 :                                                       \
  86                   "memory"                                              \
  87         );                                                              \
  88 } while (0)
  89
  90 #define DSP_AUX_SAVE_RESTORE(_saveto, _readfrom, _aux)                  \
  91         AUX_SAVE_RESTORE(_saveto, _readfrom,                            \
  92                 offsetof(struct dsp_callee_regs, _aux),                 \
  93                 ARC_AUX_##_aux)
  94
  95 static inline void dsp_save_restore(struct task_struct *prev,
  96                                         struct task_struct *next)
  97 {
  98         long unsigned int *saveto = &prev->thread.dsp.ACC0_GLO;
  99         long unsigned int *readfrom = &next->thread.dsp.ACC0_GLO;
 100
 101         DSP_AUX_SAVE_RESTORE(saveto, readfrom, ACC0_GLO);
 102         DSP_AUX_SAVE_RESTORE(saveto, readfrom, ACC0_GHI);
 103
 104         DSP_AUX_SAVE_RESTORE(saveto, readfrom, DSP_BFLY0);
 105         DSP_AUX_SAVE_RESTORE(saveto, readfrom, DSP_FFT_CTRL);
 106 }
 107
 108 #else /* !CONFIG_ARC_DSP_SAVE_RESTORE_REGS */
 109 #define dsp_save_restore(p, n)
 110 #endif /* CONFIG_ARC_DSP_SAVE_RESTORE_REGS */
 111
 112 static inline bool dsp_exist(void)
 113 {
 114         struct bcr_generic bcr;
 115
 116         READ_BCR(ARC_AUX_DSP_BUILD, bcr);
 117         return !!bcr.ver;
 118 }
 119
 120 static inline void dsp_config_check(void)
 121 {
 122         CHK_OPT_STRICT(CONFIG_ARC_DSP_HANDLED, dsp_exist());
 123 }
 124
 125 #endif /* __ASEMBLY__ */
 126 #endif /* __ASM_ARC_DSP_IMPL_H */