target/linux/generic/backport-5.4/300-MIPS-Exclude-more-dsemul-code-when-CONFIG_MIPS_FP_SU.patch

   1 From d96c3157f9ca177727fbad960fcf6f52f145f471 Mon Sep 17 00:00:00 2001
   2 From: Yousong Zhou <yszhou4tech@gmail.com>
   3 Date: Thu, 9 Jan 2020 11:33:19 +0800
   4 Subject: [PATCH] MIPS: Exclude more dsemul code when CONFIG_MIPS_FP_SUPPORT=n
   5
   6 This furthers what commit 42b10815d559 ("MIPS: Don't compile math-emu
   7 when CONFIG_MIPS_FP_SUPPORT=n") has done
   8
   9 Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
  10 ---
  11  arch/mips/include/asm/processor.h | 12 ++++++------
  12  arch/mips/kernel/process.c        | 10 ++++++++--
  13  arch/mips/kernel/vdso.c           | 26 +++++++++++++++-----------
  14  3 files changed, 29 insertions(+), 19 deletions(-)
  15
  16 --- a/arch/mips/include/asm/processor.h
  17 +++ b/arch/mips/include/asm/processor.h
  18 @@ -253,13 +253,13 @@ struct thread_struct {
  19  #ifdef CONFIG_MIPS_FP_SUPPORT
  20         /* Saved fpu/fpu emulator stuff. */
  21         struct mips_fpu_struct fpu FPU_ALIGN;
  22 -#endif
  23         /* Assigned branch delay slot 'emulation' frame */
  24         atomic_t bd_emu_frame;
  25         /* PC of the branch from a branch delay slot 'emulation' */
  26         unsigned long bd_emu_branch_pc;
  27         /* PC to continue from following a branch delay slot 'emulation' */
  28         unsigned long bd_emu_cont_pc;
  29 +#endif
  30  #ifdef CONFIG_MIPS_MT_FPAFF
  31         /* Emulated instruction count */
  32         unsigned long emulated_fp;
  33 @@ -302,7 +302,11 @@ struct thread_struct {
  34                 .fpr            = {{{0,},},},                   \
  35                 .fcr31          = 0,                            \
  36                 .msacsr         = 0,                            \
  37 -       },
  38 +       },                                                      \
  39 +       /* Delay slot emulation */                              \
  40 +       .bd_emu_frame = ATOMIC_INIT(BD_EMUFRAME_NONE),          \
  41 +       .bd_emu_branch_pc = 0,                                  \
  42 +       .bd_emu_cont_pc = 0,
  43  #else
  44  # define FPU_INIT
  45  #endif
  46 @@ -334,10 +338,6 @@ struct thread_struct {
  47          * FPU affinity state (null if not FPAFF)               \
  48          */                                                     \
  49         FPAFF_INIT                                              \
  50 -       /* Delay slot emulation */                              \
  51 -       .bd_emu_frame = ATOMIC_INIT(BD_EMUFRAME_NONE),          \
  52 -       .bd_emu_branch_pc = 0,                                  \
  53 -       .bd_emu_cont_pc = 0,                                    \
  54         /*                                                      \
  55          * Saved DSP stuff                                      \
  56          */                                                     \
  57 --- a/arch/mips/kernel/process.c
  58 +++ b/arch/mips/kernel/process.c
  59 @@ -75,7 +75,9 @@ void start_thread(struct pt_regs * regs,
  60         lose_fpu(0);
  61         clear_thread_flag(TIF_MSA_CTX_LIVE);
  62         clear_used_math();
  63 +#ifdef CONFIG_MIPS_FP_SUPPORT
  64         atomic_set(&current->thread.bd_emu_frame, BD_EMUFRAME_NONE);
  65 +#endif
  66         init_dsp();
  67         regs->cp0_epc = pc;
  68         regs->regs[29] = sp;
  69 @@ -176,7 +178,9 @@ int copy_thread_tls(unsigned long clone_
  70         clear_tsk_thread_flag(p, TIF_FPUBOUND);
  71  #endif /* CONFIG_MIPS_MT_FPAFF */
  72
  73 +#ifdef CONFIG_MIPS_FP_SUPPORT
  74         atomic_set(&p->thread.bd_emu_frame, BD_EMUFRAME_NONE);
  75 +#endif
  76
  77         if (clone_flags & CLONE_SETTLS)
  78                 ti->tp_value = tls;
  79 @@ -650,8 +654,10 @@ unsigned long mips_stack_top(void)
  80  {
  81         unsigned long top = TASK_SIZE & PAGE_MASK;
  82
  83 -       /* One page for branch delay slot "emulation" */
  84 -       top -= PAGE_SIZE;
  85 +       if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {
  86 +               /* One page for branch delay slot "emulation" */
  87 +               top -= PAGE_SIZE;
  88 +       }
  89
  90         /* Space for the VDSO, data page & GIC user page */
  91         top -= PAGE_ALIGN(current->thread.abi->vdso->size);
  92 --- a/arch/mips/kernel/vdso.c
  93 +++ b/arch/mips/kernel/vdso.c
  94 @@ -71,10 +71,12 @@ subsys_initcall(init_vdso);
  95
  96  static unsigned long vdso_base(void)
  97  {
  98 -       unsigned long base;
  99 +       unsigned long base = STACK_TOP;
 100
 101 -       /* Skip the delay slot emulation page */
 102 -       base = STACK_TOP + PAGE_SIZE;
 103 +       if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {
 104 +               /* Skip the delay slot emulation page */
 105 +               base += PAGE_SIZE;
 106 +       }
 107
 108         if (current->flags & PF_RANDOMIZE) {
 109                 base += get_random_int() & (VDSO_RANDOMIZE_SIZE - 1);
 110 @@ -95,14 +97,16 @@ int arch_setup_additional_pages(struct l
 111         if (down_write_killable(&mm->mmap_sem))
 112                 return -EINTR;
 113
 114 -       /* Map delay slot emulation page */
 115 -       base = mmap_region(NULL, STACK_TOP, PAGE_SIZE,
 116 -                          VM_READ | VM_EXEC |
 117 -                          VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
 118 -                          0, NULL);
 119 -       if (IS_ERR_VALUE(base)) {
 120 -               ret = base;
 121 -               goto out;
 122 +       if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {
 123 +               /* Map delay slot emulation page */
 124 +               base = mmap_region(NULL, STACK_TOP, PAGE_SIZE,
 125 +                               VM_READ | VM_EXEC |
 126 +                               VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
 127 +                               0, NULL);
 128 +               if (IS_ERR_VALUE(base)) {
 129 +                       ret = base;
 130 +                       goto out;
 131 +               }
 132         }
 133
 134         /*