rom/exec/exec_locks.c

   1 /*
   2     Copyright © 2017, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 /*
   7     Desc:
   8
   9         Exposes a Public resource on smp systems that allows user space code
  10         to create (spin) locks, and exposes locking on exec Lists.
  11
  12         e.g. LDDemon uses this to lock access to the system lists
  13         when scanning devices/libraries etc - since are not allowed
  14         to directly call the kernel locking functions or access the exec locks.
  15
  16     Lang: english
  17 */
  18
  19 #include <aros/config.h>
  20
  21 #if defined(__AROSEXEC_SMP__)
  22
  23 #define DEBUG 1
  24
  25 #include <aros/debug.h>
  26 #include <proto/exec.h>
  27
  28 #include "exec_debug.h"
  29 #include "exec_intern.h"
  30 #include "exec_locks.h"
  31
  32 int ExecLock__InternObtainSystemLock(struct List *systemList, ULONG mode, ULONG flags)
  33 {
  34     spinlock_t *sysListLock = NULL;
  35     D(char *name = "??");
  36
  37     if (systemList)
  38     {
  39         if (&SysBase->ResourceList == systemList) {
  40             D(name="ResourceList");
  41             sysListLock = &PrivExecBase(SysBase)->ResourceListSpinLock;
  42         }
  43         else if (&SysBase->DeviceList == systemList) {
  44             D(name="DeviceList");
  45             sysListLock = &PrivExecBase(SysBase)->DeviceListSpinLock;
  46         }
  47         else if (&SysBase->IntrList == systemList) {
  48             D(name="IntrList");
  49             sysListLock = &PrivExecBase(SysBase)->IntrListSpinLock;
  50         }
  51         else if (&SysBase->LibList == systemList) {
  52             D(name="LibList");
  53             sysListLock = &PrivExecBase(SysBase)->LibListSpinLock;
  54         }
  55         else if (&SysBase->PortList == systemList) {
  56             D(name="PortList");
  57             sysListLock = &PrivExecBase(SysBase)->PortListSpinLock;
  58         }
  59         else if (&SysBase->SemaphoreList == systemList) {
  60             D(name="SemaphoreList");
  61             sysListLock = &PrivExecBase(SysBase)->SemListSpinLock;
  62         }
  63     }
  64     D(bug("[Exec:Lock] %s(), List='%s' (%p), mode=%s, flags=%d\n", __func__, name, systemList, mode == SPINLOCK_MODE_WRITE ? "write":"read", flags));
  65     if (sysListLock)
  66     {
  67         if (flags && LOCKF_DISABLE)
  68             Disable();
  69         if (flags && LOCKF_FORBID)
  70             Forbid();
  71
  72         EXEC_SPINLOCK_LOCK(sysListLock, NULL, mode);
  73
  74         return TRUE;
  75     }
  76     return FALSE;
  77 }
  78
  79 void ExecLock__InternReleaseSystemLock(struct List *systemList, ULONG flags)
  80 {
  81     spinlock_t *sysListLock = NULL;
  82     D(char *name = "??");
  83
  84     if (systemList)
  85     {
  86         if (&SysBase->ResourceList == systemList) {
  87             D(name="ResourceList");
  88             sysListLock = &PrivExecBase(SysBase)->ResourceListSpinLock;
  89         }
  90         else if (&SysBase->DeviceList == systemList) {
  91             D(name="DeviceList");
  92             sysListLock = &PrivExecBase(SysBase)->DeviceListSpinLock;
  93         }
  94         else if (&SysBase->IntrList == systemList) {
  95             D(name="IntrList");
  96             sysListLock = &PrivExecBase(SysBase)->IntrListSpinLock;
  97         }
  98         else if (&SysBase->LibList == systemList) {
  99             D(name="LibList");
 100             sysListLock = &PrivExecBase(SysBase)->LibListSpinLock;
 101         }
 102         else if (&SysBase->PortList == systemList) {
 103             D(name="PortList");
 104             sysListLock = &PrivExecBase(SysBase)->PortListSpinLock;
 105         }
 106         else if (&SysBase->SemaphoreList == systemList) {
 107             D(name="SemaphoreList");
 108             sysListLock = &PrivExecBase(SysBase)->SemListSpinLock;
 109         }
 110     }
 111     D(bug("[Exec:Lock] %s(), list='%s' (%p), flags=%d\n", __func__, name, systemList, flags));
 112     if (sysListLock)
 113     {
 114         EXEC_SPINLOCK_UNLOCK(sysListLock);
 115
 116         if (flags & LOCKF_FORBID)
 117             Permit();
 118         if (flags & LOCKF_DISABLE)
 119             Enable();
 120     }
 121 }
 122 #if 0
 123 /* Locking mechanism for userspace */
 124 void *ExecLock__AllocLock()
 125 {
 126     spinlock_t *publicLock;
 127
 128     D(bug("[Exec:Lock] %s()\n", __func__));
 129
 130     if ((publicLock = (spinlock_t *)AllocMem(sizeof(spinlock_t), MEMF_ANY)) != NULL)
 131     {
 132         EXEC_SPINLOCK_INIT(publicLock);
 133     }
 134     return publicLock;
 135 }
 136
 137 void *ExecLock__ObtainLock(void *lock, ULONG mode)
 138 {
 139     D(bug("[Exec:Lock] %s()\n", __func__));
 140
 141     if (lock)
 142     {
 143         EXEC_SPINLOCK_LOCK(lock, NULL, mode);
 144         return (void *)TRUE;
 145     }
 146     return NULL;
 147 }
 148
 149 void ExecLock__ReleaseLock(void *lock)
 150 {
 151     D(bug("[Exec:Lock] %s()\n", __func__));
 152
 153     if (lock)
 154     {
 155         EXEC_SPINLOCK_UNLOCK(lock);
 156     }
 157 }
 158
 159 void ExecLock__FreeLock(void *lock)
 160 {
 161     D(bug("[Exec:Lock] %s()\n", __func__));
 162
 163     if (lock)
 164     {
 165         FreeMem(lock, sizeof(spinlock_t));
 166     }
 167 }
 168 #endif
 169
 170 AROS_LH1 (struct ExecLockBase *, ResourceOpen,
 171     AROS_LHA (ULONG, version, D0),
 172     struct ExecLockBase *, ExecLockBase, 1, ExecLock
 173 )
 174 {
 175     AROS_LIBFUNC_INIT
 176
 177     D(bug("[Exec:Lock] %s()\n", __func__));
 178
 179     ((struct Library *)ExecLockBase)->lib_OpenCnt++;
 180     ((struct Library *)ExecLockBase)->lib_Flags &= ~LIBF_DELEXP;
 181
 182     return ExecLockBase;
 183
 184     AROS_LIBFUNC_EXIT
 185 }
 186
 187 AROS_LH3 (int, ObtainSystemLock,
 188     AROS_LHA(struct List *, systemList, A0),
 189     AROS_LHA(ULONG, mode, D0),
 190     AROS_LHA(ULONG, flags, D1),
 191     struct ExecLockBase *, ExecLockBase, 5, ExecLock
 192 )
 193 {
 194     AROS_LIBFUNC_INIT
 195
 196     D(bug("[Exec:Lock] %s()\n", __func__));
 197
 198     return ExecLock__InternObtainSystemLock(systemList, mode, flags);
 199
 200     AROS_LIBFUNC_EXIT
 201 }
 202
 203 AROS_LH2 (void, ReleaseSystemLock,
 204     AROS_LHA(struct List *, systemList, A0),
 205     AROS_LHA(ULONG, flags, D1),
 206     struct ExecLockBase *, ExecLockBase, 6, ExecLock
 207 )
 208 {
 209     AROS_LIBFUNC_INIT
 210
 211     D(bug("[Exec:Lock] %s()\n", __func__));
 212
 213     ExecLock__InternReleaseSystemLock(systemList, flags);
 214
 215     AROS_LIBFUNC_EXIT
 216 }
 217
 218
 219 const APTR ExecLock__FuncTable[]=
 220 {
 221     &AROS_SLIB_ENTRY(ResourceOpen,ExecLock,1),
 222     NULL,
 223     NULL,
 224     NULL,
 225     /* Version 36 */
 226     &AROS_SLIB_ENTRY(ObtainSystemLock,ExecLock,5),
 227     &AROS_SLIB_ENTRY(ReleaseSystemLock,ExecLock,6),
 228     (void *)-1
 229 };
 230
 231
 232 APTR ExecLock__PrepareBase(struct MemHeader *mh)
 233 {
 234     APTR ExecLockResBase;
 235     struct ExecLockBase *ExecLockBase;
 236
 237     D(bug("[Exec:Lock] %s()\n", __func__));
 238
 239     ExecLockResBase = Allocate(mh, sizeof(struct ExecLockBase) + sizeof(*ExecLock__FuncTable));
 240     ExecLockBase = (struct ExecLockBase *)((IPTR)ExecLockResBase + sizeof(*ExecLock__FuncTable));
 241
 242     MakeFunctions(ExecLockBase, ExecLock__FuncTable, NULL);
 243
 244     ExecLockBase->el_Node.ln_Name = "execlock.resource";
 245     ExecLockBase->el_Node.ln_Type = NT_RESOURCE;
 246     ExecLockBase->ObtainSystemLock = ExecLock__InternObtainSystemLock;
 247     ExecLockBase->ReleaseSystemLock = ExecLock__InternReleaseSystemLock;
 248
 249     AddResource(ExecLockBase);
 250
 251     return ExecLockBase;
 252 }
 253
 254 #endif