recipes/linux/linux-omap-pm-2.6.29/vfp/02-vfp-ptrace.patch

   1 From: Catalin Marinas <catalin.marinas@arm.com>
   2 Date: Wed, 11 Feb 2009 11:12:56 +0000 (+0100)
   3 Subject: 5387/1: Add ptrace VFP support on ARM
   4 X-Git-Url: http://siarhei.siamashka.name/gitweb/?p=linux-omap-2.6.git;a=commitdiff_plain;h=4dd5beb2244f15c895aba46474bd89545327d1a6
   5
   6 5387/1: Add ptrace VFP support on ARM
   7
   8 [ARM] 5387/1: Add ptrace VFP support on ARM
   9
  10 This patch adds ptrace support for setting and getting the VFP registers
  11 using PTRACE_SETVFPREGS and PTRACE_GETVFPREGS. The user_vfp structure
  12 defined in asm/user.h contains 32 double registers (to cover VFPv3 and
  13 Neon hardware) and the FPSCR register.
  14
  15 Cc: Paul Brook <paul@codesourcery.com>
  16 Cc: Daniel Jacobowitz <dan@codesourcery.com>
  17 Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
  18 Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
  19 ---
  20
  21 diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
  22 index 7319261..236a06b 100644
  23 --- a/arch/arm/include/asm/ptrace.h
  24 +++ b/arch/arm/include/asm/ptrace.h
  25 @@ -27,6 +27,8 @@
  26  /* PTRACE_SYSCALL is 24 */
  27  #define PTRACE_GETCRUNCHREGS   25
  28  #define PTRACE_SETCRUNCHREGS   26
  29 +#define PTRACE_GETVFPREGS      27
  30 +#define PTRACE_SETVFPREGS      28
  31
  32  /*
  33   * PSR bits
  34 diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
  35 index 68b9ec8..b9dc8a8 100644
  36 --- a/arch/arm/include/asm/thread_info.h
  37 +++ b/arch/arm/include/asm/thread_info.h
  38 @@ -113,6 +113,8 @@ extern void iwmmxt_task_restore(struct thread_info *, void *);
  39  extern void iwmmxt_task_release(struct thread_info *);
  40  extern void iwmmxt_task_switch(struct thread_info *);
  41
  42 +extern void vfp_sync_state(struct thread_info *thread);
  43 +
  44  #endif
  45
  46  /*
  47 diff --git a/arch/arm/include/asm/user.h b/arch/arm/include/asm/user.h
  48 index 825c1e7..df95e05 100644
  49 --- a/arch/arm/include/asm/user.h
  50 +++ b/arch/arm/include/asm/user.h
  51 @@ -81,4 +81,13 @@ struct user{
  52  #define HOST_TEXT_START_ADDR (u.start_code)
  53  #define HOST_STACK_END_ADDR (u.start_stack + u.u_ssize * NBPG)
  54
  55 +/*
  56 + * User specific VFP registers. If only VFPv2 is present, registers 16 to 31
  57 + * are ignored by the ptrace system call.
  58 + */
  59 +struct user_vfp {
  60 +       unsigned long long fpregs[32];
  61 +       unsigned long fpscr;
  62 +};
  63 +
  64  #endif /* _ARM_USER_H */
  65 diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
  66 index df653ea..89882a1 100644
  67 --- a/arch/arm/kernel/ptrace.c
  68 +++ b/arch/arm/kernel/ptrace.c
  69 @@ -653,6 +653,54 @@ static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
  70  }
  71  #endif
  72
  73 +#ifdef CONFIG_VFP
  74 +/*
  75 + * Get the child VFP state.
  76 + */
  77 +static int ptrace_getvfpregs(struct task_struct *tsk, void __user *data)
  78 +{
  79 +       struct thread_info *thread = task_thread_info(tsk);
  80 +       union vfp_state *vfp = &thread->vfpstate;
  81 +       struct user_vfp __user *ufp = data;
  82 +
  83 +       vfp_sync_state(thread);
  84 +
  85 +       /* copy the floating point registers */
  86 +       if (copy_to_user(&ufp->fpregs, &vfp->hard.fpregs,
  87 +                        sizeof(vfp->hard.fpregs)))
  88 +               return -EFAULT;
  89 +
  90 +       /* copy the status and control register */
  91 +       if (put_user(vfp->hard.fpscr, &ufp->fpscr))
  92 +               return -EFAULT;
  93 +
  94 +       return 0;
  95 +}
  96 +
  97 +/*
  98 + * Set the child VFP state.
  99 + */
 100 +static int ptrace_setvfpregs(struct task_struct *tsk, void __user *data)
 101 +{
 102 +       struct thread_info *thread = task_thread_info(tsk);
 103 +       union vfp_state *vfp = &thread->vfpstate;
 104 +       struct user_vfp __user *ufp = data;
 105 +
 106 +       vfp_sync_state(thread);
 107 +
 108 +       /* copy the floating point registers */
 109 +       if (copy_from_user(&vfp->hard.fpregs, &ufp->fpregs,
 110 +                          sizeof(vfp->hard.fpregs)))
 111 +               return -EFAULT;
 112 +
 113 +       /* copy the status and control register */
 114 +       if (get_user(vfp->hard.fpscr, &ufp->fpscr))
 115 +               return -EFAULT;
 116 +
 117 +       return 0;
 118 +}
 119 +#endif
 120 +
 121  long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 122  {
 123         int ret;
 124 @@ -775,6 +823,16 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 125                         break;
 126  #endif
 127
 128 +#ifdef CONFIG_VFP
 129 +               case PTRACE_GETVFPREGS:
 130 +                       ret = ptrace_getvfpregs(child, (void __user *)data);
 131 +                       break;
 132 +
 133 +               case PTRACE_SETVFPREGS:
 134 +                       ret = ptrace_setvfpregs(child, (void __user *)data);
 135 +                       break;
 136 +#endif
 137 +
 138                 default:
 139                         ret = ptrace_request(child, request, addr, data);
 140                         break;
 141 diff --git a/arch/arm/vfp/vfp.h b/arch/arm/vfp/vfp.h
 142 index 8de86e4..c8c98dd 100644
 143 --- a/arch/arm/vfp/vfp.h
 144 +++ b/arch/arm/vfp/vfp.h
 145 @@ -377,6 +377,4 @@ struct op {
 146         u32 flags;
 147  };
 148
 149 -#if defined(CONFIG_SMP) || defined(CONFIG_PM)
 150  extern void vfp_save_state(void *location, u32 fpexc);
 151 -#endif
 152 diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S
 153 index b21f43f..902d396 100644
 154 --- a/arch/arm/vfp/vfphw.S
 155 +++ b/arch/arm/vfp/vfphw.S
 156 @@ -166,7 +166,6 @@ process_exception:
 157                                         @ retry the faulted instruction
 158  ENDPROC(vfp_support_entry)
 159
 160 -#if defined(CONFIG_SMP) || defined(CONFIG_PM)
 161  ENTRY(vfp_save_state)
 162         @ Save the current VFP state
 163         @ r0 - save location
 164 @@ -181,7 +180,6 @@ ENTRY(vfp_save_state)
 165         stmia   r0, {r1, r2, r3, r12}   @ save FPEXC, FPSCR, FPINST, FPINST2
 166         mov     pc, lr
 167  ENDPROC(vfp_save_state)
 168 -#endif
 169
 170  last_VFP_context_address:
 171         .word   last_VFP_context
 172 diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
 173 index 9f476a1..7e12390 100644
 174 --- a/arch/arm/vfp/vfpmodule.c
 175 +++ b/arch/arm/vfp/vfpmodule.c
 176 @@ -377,6 +377,55 @@ static void vfp_pm_init(void)
 177  static inline void vfp_pm_init(void) { }
 178  #endif /* CONFIG_PM */
 179
 180 +/*
 181 + * Synchronise the hardware VFP state of a thread other than current with the
 182 + * saved one. This function is used by the ptrace mechanism.
 183 + */
 184 +#ifdef CONFIG_SMP
 185 +void vfp_sync_state(struct thread_info *thread)
 186 +{
 187 +       /*
 188 +        * On SMP systems, the VFP state is automatically saved at every
 189 +        * context switch. We mark the thread VFP state as belonging to a
 190 +        * non-existent CPU so that the saved one will be reloaded when
 191 +        * needed.
 192 +        */
 193 +       thread->vfpstate.hard.cpu = NR_CPUS;
 194 +}
 195 +#else
 196 +void vfp_sync_state(struct thread_info *thread)
 197 +{
 198 +       unsigned int cpu = get_cpu();
 199 +       u32 fpexc = fmrx(FPEXC);
 200 +
 201 +       /*
 202 +        * If VFP is enabled, the previous state was already saved and
 203 +        * last_VFP_context updated.
 204 +        */
 205 +       if (fpexc & FPEXC_EN)
 206 +               goto out;
 207 +
 208 +       if (!last_VFP_context[cpu])
 209 +               goto out;
 210 +
 211 +       /*
 212 +        * Save the last VFP state on this CPU.
 213 +        */
 214 +       fmxr(FPEXC, fpexc | FPEXC_EN);
 215 +       vfp_save_state(last_VFP_context[cpu], fpexc);
 216 +       fmxr(FPEXC, fpexc);
 217 +
 218 +       /*
 219 +        * Set the context to NULL to force a reload the next time the thread
 220 +        * uses the VFP.
 221 +        */
 222 +       last_VFP_context[cpu] = NULL;
 223 +
 224 +out:
 225 +       put_cpu();
 226 +}
 227 +#endif
 228 +
 229  #include <linux/smp.h>
 230
 231  /*