Changeset fbcdeb8 in mainline for abi/include/ipc/methods.h

Timestamp:

2011-12-19T17:30:39Z (12 years ago)

Author:

Martin Decky <martin@…>

Branches:

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

Children:

58f6229

Parents:

24cf31f1

Message:

Remove the two-phase way of creating virtual memory areas (first asking for a mappable address and then mapping it) which was prone to race conditions when two or more calls to as_get_mappable_page() and as_area_create() were interleaved. This for example caused the e1k driver to randomly fail.

The memory area related syscalls and IPC calls have all been altered to accept a special value (void *) -1, representing a demand to atomically search for a mappable address space "hole" and map to it.

Individual changes:

• IPC_M_SHARE_OUT: the destination address space area is supplied by the kernel, the callee only specifies the lower bound

(the address is returned to the callee via a pointer in an IPC reply argument)

• IPC_M_SHARE_IN: the destination address space ares is supplied by the kernel, the callee only specifies the lower bound

(the address is returned to the caller as usual via an IPC argument)

• SYS_AS_GET_UNMAPPED_AREA was removed
• dummy implementations of SYS_PHYSMEM_UNMAP and SYS_IOSPACE_DISABLE were added for the sake of symmetry (they do nothing yet)
• SYS_PHYSMEM_MAP and SYS_DMAMEM_MAP were altered to accept (void *) -1 as address space area base and a lower bound
• kernel as_area_create() and as_area_share() were altered to accept (void *) -1 as address space area base and a lower bound
• uspace libraries and programs were altered to reflect the new API

File:

• abi/include/ipc/methods.h (modified) (3 diffs)

abi/include/ipc/methods.h

@@ -127 +127 @@
  *
  * on answer, the recipient must set:
- * - ARG1 - dst as_area base adress
+ *
+ * - ARG1 - dst as_area lower bound
+ * - ARG2 - dst as_area base adress pointer
+ *          (filled automatically by the kernel)
  *
  */
@@ -133 +136 @@
 
 /** Receive as_area over IPC.
- * - ARG1 - destination as_area base address
- * - ARG2 - destination as_area size
- * - ARG3 - user defined argument
+ * - ARG1 - destination as_area size
+ * - ARG2 - user defined argument
  *
  * on answer, the recipient must set:
@@ -141 +143 @@
  * - ARG1 - source as_area base address
  * - ARG2 - flags that will be used for sharing
+ * - ARG3 - dst as_area lower bound
+ * - ARG4 - dst as_area base address (filled automatically by kernel)
  *
  */