src/runtime/os.h

   1 /*
   2  * common interface for OS-dependent functions
   3  */
   4
   5 /*
   6  * This software is part of the SBCL system. See the README file for
   7  * more information.
   8  *
   9  * This software is derived from the CMU CL system, which was
  10  * written at Carnegie Mellon University and released into the
  11  * public domain. The software is in the public domain and is
  12  * provided with absolutely no warranty. See the COPYING and CREDITS
  13  * files for more information.
  14  */
  15
  16 #if !defined(_OS_H_INCLUDED_)
  17
  18 #define _OS_H_INCLUDED_
  19
  20 #include "runtime.h"
  21
  22 /* Some standard preprocessor definitions and typedefs are needed from
  23  * the OS-specific #include files. This is an attempt to document
  24  * them on 20000729, by WHN the impatient reverse engineer.
  25  *
  26  * OS_VM_PROT_READ, OS_VM_PROT_WRITE, OS_VM_PROT_EXECUTE
  27  *   flags for mmap, mprotect, etc. controlling memory protection
  28  * os_vm_prot_t
  29  *   type used for flags for mmap, mprotect, etc.
  30  *
  31  * os_vm_address_t
  32  *   the type used to represent addresses? (dunno why not just void*)
  33  * os_vm_size_t, os_vm_off_t
  34  *   corresponding to standard (POSIX?) types size_t, off_t
  35  * os_context_t
  36  *   the type used to represent context in a POSIX sigaction SA_SIGACTION
  37  *   handler, i.e. the actual type of the thing pointed to by the
  38  *   void* third argument of a handler */
  39
  40 #include "target-os.h"
  41
  42
  43 #define OS_VM_PROT_ALL \
  44   (OS_VM_PROT_READ | OS_VM_PROT_WRITE | OS_VM_PROT_EXECUTE)
  45
  46 extern os_vm_size_t os_vm_page_size;
  47
  48 /* Do anything we need to do when starting up the runtime environment
  49  * in this OS. */
  50 extern void os_init(void);
  51
  52 /* Install any OS-dependent low-level signal handlers which are needed
  53  * by the runtime environment. E.g. the signals raised by a violation
  54  * of the gencgc write barrier need to be caught at a low level, and
  55  * they may be SIGSEGV on one OS and SIGBUS on another, so we install
  56  * them in an OS-dependent way. */
  57 extern void os_install_interrupt_handlers(void);
  58
  59 /* Clear a possibly-huge region of memory using any tricks available to
  60  * do it efficiently, e.g. possibly unmapping it and then remapping it.
  61  *
  62  * FIXME: For the x86 Linux/OpenBSD/FreeBSD ports, I'd be somewhat
  63  * surprised if bzero() wasn't substantially as efficient as
  64  * any tricks like this. It might make sense to benchmark it
  65  * and simplify if the difference isn't too large. */
  66 extern void os_zero(os_vm_address_t addr, os_vm_size_t length);
  67
  68 /* It looks as though this function allocates 'len' bytes at 'addr',
  69  * or at an OS-chosen address if 'addr' is zero.
  70  *
  71  * FIXME: There was some documentation for these functions in
  72  * "hp-ux.c" in the old CMU CL code. Perhaps move/merge it in here. */
  73 extern os_vm_address_t os_validate(os_vm_address_t addr, os_vm_size_t len);
  74
  75 /* This function seems to undo the effect of os_validate(..). */
  76 extern void os_invalidate(os_vm_address_t addr, os_vm_size_t len);
  77
  78 /* This maps a file into memory, or calls lose(..) for various
  79  * failures. */
  80 extern os_vm_address_t os_map(int fd,
  81                               int offset,
  82                               os_vm_address_t addr,
  83                               os_vm_size_t len);
  84
  85 /* This presumably flushes the instruction cache, if that can be done
  86  * explicitly. (It doesn't seem to be an issue for the i386 port,
  87  * which is all that exists for SBCL. It might be important for some
  88  * other architecture which CMU CL has been ported to, though. */
  89 extern void os_flush_icache(os_vm_address_t addr, os_vm_size_t len);
  90
  91 /* This sets access rights for an area of memory, e.g.
  92  * write-protecting a page so that the garbage collector can find out
  93  * whether it's modified by handling the signal. */
  94 extern void os_protect(os_vm_address_t addr,
  95                        os_vm_size_t len,
  96                        os_vm_prot_t protection);
  97
  98 /* This returns true for an address which makes sense at the Lisp level. */
  99 extern boolean is_valid_lisp_addr(os_vm_address_t test);
 100
 101 /* Given a signal context, return the address for storage of the
 102  * register, of the specified offset, for that context. The offset is
 103  * defined in the storage class (SC) defined in the Lisp virtual
 104  * machine (i.e. the file "vm.lisp" for the appropriate architecture). */
 105 os_context_register_t *
 106 os_context_register_addr(os_context_t *context, int offset);
 107
 108 /* FIXME: Pending investigation, this #ifdef stays as alpha. If it
 109  * turns out that the alpha truly requires this, it can change to
 110  * ARCH_HAS_FLOAT_REGISTERS (currently #defined in alpha-arch.h -- CSR
 111  * 2002-02-04 */
 112 #ifdef alpha
 113 os_context_register_t *
 114 os_context_float_register_addr(os_context_t *context, int offset);
 115 #endif
 116
 117 /* Given a signal context, return the address for storage of the
 118  * program counter for that context. */
 119 os_context_register_t *os_context_pc_addr(os_context_t *context);
 120 #ifdef ARCH_HAS_NPC_REGISTER
 121 os_context_register_t *os_context_npc_addr(os_context_t *context);
 122 #endif
 123 #ifdef ARCH_HAS_LINK_REGISTER
 124 os_context_register_t *os_context_lr_addr(os_context_t *context);
 125 #endif
 126
 127 /* Given a signal context, return the address for storage of the
 128  * system stack pointer for that context. */
 129 #ifdef ARCH_HAS_STACK_POINTER
 130 os_context_register_t *os_context_sp_addr(os_context_t *context);
 131 #endif
 132 /* Given a signal context, return the address for storage of the
 133  * signal mask for that context. */
 134 sigset_t *os_context_sigmask_addr(os_context_t *context);
 135
 136 /* (Note that there may be other accessors for os_context_t which
 137  * depend not only on the OS, but also on the architecture, e.g.
 138  * getting at EFL/EFLAGS on the x86. Such things are defined in the
 139  * architecture-dependence files, not the OS-dependence files.) */
 140
 141 /* These are not architecture-specific functions, but are instead
 142  * general utilities defined in terms of the architecture-specific
 143  * function os_validate(..) and os_invalidate(..).
 144  *
 145  * FIXME: os_reallocate(..) is complicated and seems no longer to be
 146  * used for anything. Perhaps we could delete it? */
 147 extern os_vm_address_t os_allocate(os_vm_size_t len);
 148 extern os_vm_address_t os_allocate_at(os_vm_address_t addr, os_vm_size_t len);
 149 extern os_vm_address_t os_reallocate(os_vm_address_t addr,
 150                                      os_vm_size_t old_len,
 151                                      os_vm_size_t len);
 152 extern void os_deallocate(os_vm_address_t addr, os_vm_size_t len);
 153
 154
 155 /* FIXME: The os_trunc_foo(..) and os_round_foo(..) macros here could
 156  * be functions. */
 157
 158 #define os_trunc_to_page(addr) \
 159     (os_vm_address_t)(((long)(addr))&~(os_vm_page_size-1))
 160 #define os_round_up_to_page(addr) \
 161     os_trunc_to_page((addr)+(os_vm_page_size-1))
 162
 163 #define os_trunc_size_to_page(size) \
 164     (os_vm_size_t)(((long)(size))&~(os_vm_page_size-1))
 165 #define os_round_up_size_to_page(size) \
 166     os_trunc_size_to_page((size)+(os_vm_page_size-1))
 167
 168 /* KLUDGE: The errno error reporting system is an ugly nonreentrant
 169  * botch which nonetheless wasn't too painful in the old days.
 170  * However, it's obviously not good for multithreaded programs, and n
 171  * order to accommodate multithreading while retaining the C-level
 172  * syntax of the old UNIX interface, errno has now been changed from a
 173  * true variable to a preprocessor definition which is too hairy for
 174  * us to try to unscrew in Lisp code. Instead, Lisp code calls this
 175  * service routine to do whatever hackery is necessary in C code, and
 176  * to return the value in a way that Lisp can understand. */
 177 int os_get_errno(void);
 178
 179 #endif