Changeset bf9cb2f in mainline for uspace/lib/c/generic/ddi.c

Timestamp:

2014-05-19T01:01:27Z (10 years ago)

Author:

Martin Decky <martin@…>

Branches:

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

Children:

10ef47ba

Parents:

527f1ca

Message:

complete the desired API semantics of physmem_map() and dmamem_map_anonymous() to be compatible with as_area_create()
(the user is allowed to request a specific virtual memory base address, the kernel uses an available base address if AS_AREA_ANY is used)

File:

• uspace/lib/c/generic/ddi.c (modified) (4 diffs)

uspace/lib/c/generic/ddi.c

@@ -71 +71 @@
  * @param flags Flags for the new address space area.
  * @param virt  Virtual address of the starting page.
- *
- * @return EOK on success
- * @return EPERM if the caller lacks the CAP_MEM_MANAGER capability
- * @return ENOENT if there is no task with specified ID
+ *              If set to AS_AREA_ANY ((void *) -1), a suitable value
+ *              is found by the kernel, otherwise the kernel tries to
+ *              obey the desired value.
+ *
+ * @return EOK on success.
+ * @return EPERM if the caller lacks the CAP_MEM_MANAGER capability.
  * @return ENOMEM if there was some problem in creating
  *         the address space area.
@@ -85 +87 @@
 }
 
+/** Lock a piece physical memory for DMA transfers.
+ *
+ * The mapping of the specified virtual memory address
+ * to physical memory address is locked in order to
+ * make it safe for DMA transferts.
+ *
+ * Caller of this function must have the CAP_MEM_MANAGER capability.
+ *
+ * @param virt      Virtual address of the memory to be locked.
+ * @param size      Number of bytes to lock.
+ * @param map_flags Desired virtual memory area flags.
+ * @param flags     Flags for the physical memory address.
+ * @param phys      Locked physical memory address.
+ *
+ * @return EOK on success.
+ * @return EPERM if the caller lacks the CAP_MEM_MANAGER capability.
+ * @return ENOMEM if there was some problem in creating
+ *         the address space area.
+ *
+ */
 int dmamem_map(void *virt, size_t size, unsigned int map_flags,
     unsigned int flags, uintptr_t *phys)
@@ -93 +115 @@
 }
 
+/** Map a piece of physical memory suitable for DMA transfers.
+ *
+ * Caller of this function must have the CAP_MEM_MANAGER capability.
+ *
+ * @param size       Number of bytes to map.
+ * @param constraint Bit mask defining the contraint on the physical
+ *                   address to be mapped.
+ * @param map_flags  Desired virtual memory area flags.
+ * @param flags      Flags for the physical memory address.
+ * @param virt       Virtual address of the starting page.
+ *                   If set to AS_AREA_ANY ((void *) -1), a suitable value
+ *                   is found by the kernel, otherwise the kernel tries to
+ *                   obey the desired value.
+ *
+ * @return EOK on success.
+ * @return EPERM if the caller lacks the CAP_MEM_MANAGER capability.
+ * @return ENOMEM if there was some problem in creating
+ *         the address space area.
+ *
+ */
 int dmamem_map_anonymous(size_t size, uintptr_t constraint,
     unsigned int map_flags, unsigned int flags, uintptr_t *phys, void **virt)
@@ -221 +263 @@
         size_t pages = SIZE2PAGES(offset + size);
         
-        void *virt_page;
+        void *virt_page = AS_AREA_ANY;
         int rc = physmem_map(phys_frame, pages,
             AS_AREA_READ | AS_AREA_WRITE, &virt_page);