Changeset f6bffee in mainline

Timestamp:

2011-04-06T20:19:04Z (13 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

55132b8, b910455

Parents:

b946bf83

Message:

Allow special flags that control processing of IPC_M_DATA_READ/WRITE in
the kernel:

• IPC_XF_NONE: default behavior
• IPC_XF_RESTRICT: restrict the transfer size if necessary

Make read() and write() use IPC_XF_RESTRICT.

Files:

• kernel/generic/include/ipc/ipc.h (modified) (1 diff)
• kernel/generic/src/ipc/sysipc.c (modified) (2 diffs)
• uspace/lib/c/generic/async.c (modified) (2 diffs)
• uspace/lib/c/generic/vfs/vfs.c (modified) (2 diffs)
• uspace/lib/c/include/async.h (modified) (2 diffs)

kernel/generic/include/ipc/ipc.h

@@ -115 +115 @@
  */
 #define IPC_FF_ROUTE_FROM_ME  (1 << 0)
+
+/* Data transfer flags. */
+#define IPC_XF_NONE             0
+
+/** Restrict the transfer size if necessary. */
+#define IPC_XF_RESTRICT         (1 << 0)
 
 /** Kernel IPC interfaces

kernel/generic/src/ipc/sysipc.c

@@ -426 +426 @@
         case IPC_M_DATA_READ: {
                 size_t size = IPC_GET_ARG2(call->data);
-                if ((size <= 0 || (size > DATA_XFER_LIMIT)))
+                if (size <= 0)
                         return ELIMIT;
-                
+                if (size > DATA_XFER_LIMIT) {
+                        int flags = IPC_GET_ARG3(call->data);
+                        if (flags & IPC_XF_RESTRICT)
+                                IPC_SET_ARG2(call->data, DATA_XFER_LIMIT);
+                        else
+                                return ELIMIT;
+                }
                 break;
         }
@@ -435 +441 @@
                 size_t size = IPC_GET_ARG2(call->data);
                 
-                if (size > DATA_XFER_LIMIT)
-                        return ELIMIT;
+                if (size > DATA_XFER_LIMIT) {
+                        int flags = IPC_GET_ARG3(call->data);
+                        if (flags & IPC_XF_RESTRICT) {
+                                size = DATA_XFER_LIMIT;
+                                IPC_SET_ARG2(call->data, size);
+                        } else
+                                return ELIMIT;
+                }
                 
                 call->buffer = (uint8_t *) malloc(size, 0);

uspace/lib/c/generic/async.c

@@ -1572 +1572 @@
  * @param dst     Address of the beginning of the destination buffer.
  * @param size    Size of the destination buffer.
+ * @param flags   Flags to control the data transfer.
  *
  * @return Zero on success or a negative error code from errno.h.
  *
  */
-int async_data_read_start(int phoneid, void *dst, size_t size)
-{
-        return async_req_2_0(phoneid, IPC_M_DATA_READ, (sysarg_t) dst,
-            (sysarg_t) size);
+int
+async_data_read_start_flexible(int phoneid, void *dst, size_t size, int flags)
+{
+        return async_req_3_0(phoneid, IPC_M_DATA_READ, (sysarg_t) dst,
+            (sysarg_t) size, (sysarg_t) flags);
 }
 
@@ -1669 +1671 @@
  * @param src     Address of the beginning of the source buffer.
  * @param size    Size of the source buffer.
+ * @param flags   Flags to control the data transfer.
  *
  * @return Zero on success or a negative error code from errno.h.
  *
  */
-int async_data_write_start(int phoneid, const void *src, size_t size)
-{
-        return async_req_2_0(phoneid, IPC_M_DATA_WRITE, (sysarg_t) src,
-            (sysarg_t) size);
+int
+async_data_write_start_flexible(int phoneid, const void *src, size_t size,
+    int flags)
+{
+        return async_req_3_0(phoneid, IPC_M_DATA_WRITE, (sysarg_t) src,
+            (sysarg_t) size, (sysarg_t) flags);
 }
 

uspace/lib/c/generic/vfs/vfs.c

@@ -378 +378 @@
         
         req = async_send_1(vfs_phone, VFS_IN_READ, fildes, &answer);
-        rc = async_data_read_start(vfs_phone, (void *)buf, nbyte);
+        rc = async_data_read_start_flexible(vfs_phone, (void *) buf, nbyte,
+            IPC_XF_RESTRICT);
         if (rc != EOK) {
                 vfs_exchange_end(vfs_phone);
@@ -407 +408 @@
         
         req = async_send_1(vfs_phone, VFS_IN_WRITE, fildes, &answer);
-        rc = async_data_write_start(vfs_phone, (void *)buf, nbyte);
+        rc = async_data_write_start_flexible(vfs_phone, (void *) buf, nbyte,
+            IPC_XF_RESTRICT);
         if (rc != EOK) {
                 vfs_exchange_end(vfs_phone);

uspace/lib/c/include/async.h

@@ -340 +340 @@
             (arg4), (answer))
 
-extern int async_data_read_start(int, void *, size_t);
+#define async_data_read_start(p, buf, len) \
+        async_data_read_start_flexible((p), (buf), (len), IPC_XF_NONE)
+
+extern int async_data_read_start_flexible(int, void *, size_t, int);
 extern bool async_data_read_receive(ipc_callid_t *, size_t *);
 extern int async_data_read_finalize(ipc_callid_t, const void *, size_t);
@@ -379 +382 @@
             (arg4), (answer))
 
-extern int async_data_write_start(int, const void *, size_t);
+#define async_data_write_start(p, buf, len) \
+        async_data_write_start_flexible((p), (buf), (len), IPC_XF_NONE)
+
+extern int async_data_write_start_flexible(int, const void *, size_t, int);
 extern bool async_data_write_receive(ipc_callid_t *, size_t *);
 extern int async_data_write_finalize(ipc_callid_t, void *, size_t);