src/runtime/mips-linux-os.c

   1 /*
   2  * This is the MIPS Linux incarnation of arch-dependent OS-dependent
   3  * routines. See also "linux-os.c".
   4  */
   5
   6 /*
   7  * This software is part of the SBCL system. See the README file for
   8  * more information.
   9  *
  10  * This software is derived from the CMU CL system, which was
  11  * written at Carnegie Mellon University and released into the
  12  * public domain. The software is in the public domain and is
  13  * provided with absolutely no warranty. See the COPYING and CREDITS
  14  * files for more information.
  15  */
  16
  17 #include <stdio.h>
  18 #include <signal.h>
  19
  20 /* for cacheflush() */
  21 #include <sys/cachectl.h>
  22
  23 #include "sbcl.h"
  24 #include "os.h"
  25 #include "arch.h"
  26
  27 #define CAUSEF_BD (1 << 31)
  28
  29 size_t os_vm_page_size;
  30
  31 int
  32 arch_os_thread_init(struct thread *thread)
  33 {
  34 #ifdef LISP_FEATURE_SB_THREAD
  35 #warning "Check threading support functions"
  36 #endif
  37     return 1;                  /* success */
  38 }
  39
  40 int
  41 arch_os_thread_cleanup(struct thread *thread)
  42 {
  43 #ifdef LISP_FEATURE_SB_THREAD
  44 #warning "Check threading support functions"
  45 #endif
  46     return 1;                  /* success */
  47 }
  48
  49 os_context_register_t *
  50 os_context_register_addr(os_context_t *context, int offset)
  51 {
  52     return &(((struct sigcontext *)&(context->uc_mcontext))->sc_regs[offset]);
  53 }
  54
  55 os_context_register_t *
  56 os_context_fpregister_addr(os_context_t *context, int offset)
  57 {
  58     return &(((struct sigcontext *)&(context->uc_mcontext))->sc_fpregs[offset]);
  59 }
  60
  61 os_context_register_t *
  62 os_context_pc_addr(os_context_t *context)
  63 {
  64     /* Why do I get all the silly ports? -- CSR, 2002-08-11 */
  65     return &(((struct sigcontext *)&(context->uc_mcontext))->sc_pc);
  66 }
  67
  68 sigset_t *
  69 os_context_sigmask_addr(os_context_t *context)
  70 {
  71     return &(context->uc_sigmask);
  72 }
  73
  74 unsigned int
  75 os_context_fp_control(os_context_t *context)
  76 {
  77     /* FIXME: Probably do something. */
  78     return 0;
  79 }
  80
  81 void
  82 os_restore_fp_control(os_context_t *context)
  83 {
  84     /* FIXME: Probably do something. */
  85 }
  86
  87 unsigned int
  88 os_context_bd_cause(os_context_t *context)
  89 {
  90     /* We need to see if whatever happened, happened because of a
  91        branch delay event */
  92     /* FIXME: However, I'm not convinced that the values that Linux
  93        puts in this slot are actually right; specifically, attempting
  94        to compile sbcl with sbcl-0.7.7.7 lead to an "infinite SIGTRAP
  95        loop" where a (BREAK 16) not in a branch delay slot would have
  96        CAUSEF_BD filled. So, we comment
  97
  98         return (((struct sigcontext *) &(context->uc_mcontext))->sc_cause
  99                 & CAUSEF_BD);
 100
 101        out and return 0 always.  -- CSR, 2002-09-02 */
 102     /* Unfortunately, returning 0 fails for taken branches because
 103        os_context_bd_cause is also used to find out if a branch
 104        emulation is needed.  We work around that by checking if the
 105        current instruction is a jump or a branch.  */
 106     extern boolean arch_insn_with_bdelay_p(unsigned int insn);
 107
 108     os_vm_address_t addr
 109         = (os_vm_address_t)(unsigned int)*os_context_pc_addr(context);
 110     unsigned int insn = *(unsigned int *)addr;
 111
 112     if (arch_insn_with_bdelay_p(insn))
 113         return CAUSEF_BD;
 114
 115     return 0;
 116 }
 117
 118 void
 119 os_flush_icache(os_vm_address_t address, os_vm_size_t length)
 120 {
 121     if (cacheflush(address, length, ICACHE) == -1)
 122         perror("cacheflush");
 123 }