xnu-792.6.22.tar.gz

[apple/xnu.git] / iokit / IOKit / IOBufferMemoryDescriptor.h

diff --git a/iokit/IOKit/IOBufferMemoryDescriptor.h b/iokit/IOKit/IOBufferMemoryDescriptor.h
index 733fa1dd10f01e49edd0e009497a56987f8ec506..afe2c1794490787ad191f192cf15b4dee17cfa00 100644 (file)
--- a/iokit/IOKit/IOBufferMemoryDescriptor.h
+++ b/iokit/IOKit/IOBufferMemoryDescriptor.h
@@ -25,14 +25,19 @@
 #include <IOKit/IOMemoryDescriptor.h>
 
 enum {
-    kIOMemoryDirectionMask             = 0x0000000f,
     kIOMemoryPhysicallyContiguous      = 0x00000010,
     kIOMemoryPageable                  = 0x00000020,
+    kIOMemoryPurgeable                 = 0x00000040,
     kIOMemorySharingTypeMask           = 0x000f0000,
     kIOMemoryUnshared                  = 0x00000000,
-    kIOMemoryKernelUserShared          = 0x00010000,
+    kIOMemoryKernelUserShared          = 0x00010000
 };
 
+#define _IOBUFFERMEMORYDESCRIPTOR_INTASKWITHOPTIONS_   1
+/*!
+    @class IOBufferMemoryDescriptor
+    @abstract Provides a simple memory descriptor that allocates its own buffer memory.
+*/
 
 class IOBufferMemoryDescriptor : public IOGeneralMemoryDescriptor
 {
@@ -42,7 +47,9 @@ protected:
 /*! @struct ExpansionData
     @discussion This structure will be used to expand the capablilties of this class in the future.
     */    
-    struct ExpansionData { };
+    struct ExpansionData {
+       vm_map_t        map;
+    };
 
 /*! @var reserved
     Reserved for future use.  (Internal use only)  */
@@ -57,7 +64,13 @@ protected:
     unsigned             _physSegCount;
 
 private:
-    OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 0);
+    virtual bool initWithOptions(
+                               IOOptionBits options,
+                               vm_size_t    capacity,
+                               vm_offset_t  alignment,
+                              task_t       inTask);
+
+    OSMetaClassDeclareReservedUsed(IOBufferMemoryDescriptor, 0);
     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 1);
     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 2);
     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 3);
@@ -126,6 +139,25 @@ public:
                                                     vm_size_t    capacity,
                                                     vm_offset_t  alignment = 1);
 
+/*! @function inTaskWithOptions
+    @abstract Creates a memory buffer with memory descriptor for that buffer. 
+    @discussion Added in Mac OS X 10.2, this method allocates a memory buffer with a given size and alignment in the task's address space specified, and returns a memory descriptor instance representing the memory. It is recommended that memory allocated for I/O or sharing via mapping be created via IOBufferMemoryDescriptor. Options passed with the request specify the kind of memory to be allocated - pageablity and sharing are specified with option bits. This function may block and so should not be called from interrupt level or while a simple lock is held.
+    @param inTask The task the buffer will be allocated in.
+    @param options Options for the allocation:<br>
+    kIOMemoryPhysicallyContiguous - pass to request memory be physically contiguous. This option is heavily discouraged. The request may fail if memory is fragmented, may cause large amounts of paging activity, and may take a very long time to execute.<br>
+    kIOMemoryPageable - pass to request memory be non-wired - the default for kernel allocated memory is wired.<br>
+    kIOMemoryPurgeable - pass to request memory that may later have its purgeable state set with IOMemoryDescriptor::setPurgeable. Only supported for kIOMemoryPageable allocations.<br>
+    kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.
+    @param capacity The number of bytes to allocate.
+    @param alignment The minimum required alignment of the buffer in bytes - 1 is the default for no required alignment. For example, pass 256 to get memory allocated at an address with bits 0-7 zero.
+    @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
+
+    static IOBufferMemoryDescriptor * inTaskWithOptions(
+                                           task_t       inTask,
+                                            IOOptionBits options,
+                                            vm_size_t    capacity,
+                                            vm_offset_t  alignment = 1);
+
     /*
      * withCapacity:
      *
@@ -210,15 +242,6 @@ public:
      * will not copy past the end of the memory descriptor's current capacity.
      */
     virtual bool appendBytes(const void *bytes, vm_size_t withLength);
-
-    /*
-     * getPhysicalSegment:
-     *
-     * Get the physical address of the buffer, relative to the current position.
-     * If the current position is at the end of the buffer, a zero is returned.
-     */
-    virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
-                                                IOByteCount * length);    
 };
 
 #endif /* !_IOBUFFERMEMORYDESCRIPTOR_H */