ReactOS 0.4.15-dev-8339-g4028de8
iomdl.c File Reference
#include <ntoskrnl.h>
#include <debug.h>
Include dependency graph for iomdl.c:

Go to the source code of this file.

Macros

#define NDEBUG
 

Functions

PMDL NTAPI IoAllocateMdl (IN PVOID VirtualAddress, IN ULONG Length, IN BOOLEAN SecondaryBuffer, IN BOOLEAN ChargeQuota, IN PIRP Irp)
 
VOID NTAPI IoBuildPartialMdl (IN PMDL SourceMdl, IN PMDL TargetMdl, IN PVOID VirtualAddress, IN ULONG Length)
 
VOID NTAPI IoFreeMdl (PMDL Mdl)
 

Macro Definition Documentation

◆ NDEBUG

#define NDEBUG

Definition at line 12 of file iomdl.c.

Function Documentation

◆ IoAllocateMdl()

PMDL NTAPI IoAllocateMdl ( IN PVOID  VirtualAddress,
IN ULONG  Length,
IN BOOLEAN  SecondaryBuffer,
IN BOOLEAN  ChargeQuota,
IN PIRP  Irp 
)

Definition at line 22 of file iomdl.c.

27{
28 PMDL Mdl = NULL, p;
29 ULONG Flags = 0;
30 ULONG Size;
31
32 /* Make sure we got a valid length */
33 ASSERT(Length != 0);
34
35 /* Fail if allocation is over 2GB */
36 if (Length & 0x80000000) return NULL;
37
38 /* Calculate the number of pages for the allocation */
40 if (Size > 23)
41 {
42 /* This is bigger then our fixed-size MDLs. Calculate real size */
43 Size *= sizeof(PFN_NUMBER);
44 Size += sizeof(MDL);
45 if (Size > MAXUSHORT) return NULL;
46 }
47 else
48 {
49 /* Use an internal fixed MDL size */
50 Size = (23 * sizeof(PFN_NUMBER)) + sizeof(MDL);
52
53 /* Allocate one from the lookaside list */
55 }
56
57 /* Check if we don't have an mdl yet */
58 if (!Mdl)
59 {
60 /* Allocate one from pool */
62 if (!Mdl) return NULL;
63 }
64
65 /* Initialize it */
67 Mdl->MdlFlags |= Flags;
68
69 /* Check if an IRP was given too */
70 if (Irp)
71 {
72 /* Check if it came with a secondary buffer */
74 {
75 /* Insert the MDL at the end */
76 p = Irp->MdlAddress;
77 while (p->Next) p = p->Next;
78 p->Next = Mdl;
79 }
80 else
81 {
82 /* Otherwise, insert it directly */
83 Irp->MdlAddress = Mdl;
84 }
85 }
86
87 /* Return the allocated mdl */
88 return Mdl;
89}
_In_ PIRP Irp
Definition: csq.h:116
#define NULL
Definition: types.h:112
#define ExAllocatePoolWithTag(hernya, size, tag)
Definition: env_spec_w32.h:350
#define NonPagedPool
Definition: env_spec_w32.h:307
GLfloat GLfloat p
Definition: glext.h:8902
#define ASSERT(a)
Definition: mode.c:44
@ LookasideMdlList
Definition: mmtypes.h:170
_In_ ULONG _In_ ULONG _In_ ULONG Length
Definition: ntddpcm.h:102
#define IopAllocateMdlFromLookaside
Definition: io.h:112
ULONG PFN_NUMBER
Definition: ke.h:9
#define TAG_MDL
Definition: tag.h:89
#define MAXUSHORT
Definition: typedefs.h:83
uint32_t ULONG
Definition: typedefs.h:59
_Must_inspect_result_ _In_ WDFDEVICE _In_ PWDF_DEVICE_PROPERTY_DATA _In_ DEVPROPTYPE _In_ ULONG Size
Definition: wdfdevice.h:4533
_Must_inspect_result_ _In_ WDFDMATRANSACTION _In_ PFN_WDF_PROGRAM_DMA _In_ WDF_DMA_DIRECTION _In_ PMDL _In_ PVOID VirtualAddress
_In_ WDFDEVICE _In_ PVOID _In_opt_ PMDL Mdl
_Must_inspect_result_ _In_ ULONG Flags
Definition: wsk.h:170
_In_ ULONG _In_ BOOLEAN SecondaryBuffer
Definition: iofuncs.h:660
#define MmInitializeMdl(_MemoryDescriptorList, _BaseVa, _Length)
#define ADDRESS_AND_SIZE_TO_SPAN_PAGES(_Va, _Size)
MDL
Definition: mmtypes.h:117
#define MDL_ALLOCATED_FIXED_SIZE
Definition: mmtypes.h:21

◆ IoBuildPartialMdl()

VOID NTAPI IoBuildPartialMdl ( IN PMDL  SourceMdl,
IN PMDL  TargetMdl,
IN PVOID  VirtualAddress,
IN ULONG  Length 
)

Definition at line 96 of file iomdl.c.

100{
101 PPFN_NUMBER TargetPages = (PPFN_NUMBER)(TargetMdl + 1);
102 PPFN_NUMBER SourcePages = (PPFN_NUMBER)(SourceMdl + 1);
104 ULONG FlagsMask = (MDL_IO_PAGE_READ |
108
109 /* Calculate the offset */
111 (ULONG_PTR)SourceMdl->StartVa) -
112 SourceMdl->ByteOffset;
113
114 /* Check if we don't have a length and calculate it */
115 if (!Length) Length = SourceMdl->ByteCount - Offset;
116
117 /* Write the process, start VA and byte data */
119 TargetMdl->Process = SourceMdl->Process;
120 TargetMdl->ByteCount = Length;
121 TargetMdl->ByteOffset = BYTE_OFFSET(VirtualAddress);
122
123 /* Recalculate the length in pages */
125
126 /* Set the MDL Flags */
128 TargetMdl->MdlFlags |= SourceMdl->MdlFlags & FlagsMask;
129 TargetMdl->MdlFlags |= MDL_PARTIAL;
130
131 /* Set the mapped VA */
132 TargetMdl->MappedSystemVa = (PCHAR)SourceMdl->MappedSystemVa + Offset;
133
134 /* Now do the copy */
135 Offset = (ULONG)(((ULONG_PTR)TargetMdl->StartVa -
136 (ULONG_PTR)SourceMdl->StartVa) >> PAGE_SHIFT);
137 SourcePages += Offset;
138 RtlCopyMemory(TargetPages, SourcePages, Length * sizeof(PFN_NUMBER));
139}
#define ULONG_PTR
Definition: config.h:101
#define PAGE_SHIFT
Definition: env_spec_w32.h:45
#define PCHAR
Definition: match.c:90
#define PAGE_ROUND_DOWN(x)
Definition: mmtypes.h:36
_In_ ULONG _In_ ULONG Offset
Definition: ntddpcm.h:101
ULONG * PPFN_NUMBER
Definition: ke.h:9
void * PVOID
Definition: typedefs.h:50
#define RtlCopyMemory(Destination, Source, Length)
Definition: typedefs.h:263
uint32_t ULONG_PTR
Definition: typedefs.h:65
_Inout_ PMDL TargetMdl
Definition: iofuncs.h:730
#define BYTE_OFFSET(Va)
#define MDL_ALLOCATED_MUST_SUCCEED
Definition: mmtypes.h:32
#define MDL_IO_SPACE
Definition: mmtypes.h:29
#define MDL_PARTIAL
Definition: mmtypes.h:22
#define MDL_IO_PAGE_READ
Definition: mmtypes.h:24
#define MDL_SOURCE_IS_NONPAGED_POOL
Definition: mmtypes.h:20
#define MDL_MAPPED_TO_SYSTEM_VA
Definition: mmtypes.h:18

Referenced by __attribute__(), _Requires_lock_held_(), CdMultipleXAAsync(), Ext2ReadWriteBlocks(), FatMultipleAsync(), FatPagingFileIo(), FreeBT_DispatchRead(), FreeBT_DispatchWrite(), FreeBT_WriteCompletion(), Mx::MxBuildPartialMdl(), NdisCopyBuffer(), ScratchBuffer_SetupReadWriteSrb(), SubmitTransferPacket(), USBSTOR_CBWCompletionRoutine(), USBSTOR_SendRequest(), VfatReadDiskPartial(), and VfatWriteDiskPartial().

◆ IoFreeMdl()

VOID NTAPI IoFreeMdl ( PMDL  Mdl)

Definition at line 146 of file iomdl.c.

147{
148 /* Tell Mm to reuse the MDL */
150
151 /* Check if this was a pool allocation */
152 if (!(Mdl->MdlFlags & MDL_ALLOCATED_FIXED_SIZE))
153 {
154 /* Free it from the pool */
156 }
157 else
158 {
159 /* Free it from the lookaside */
161 }
162}
#define ExFreePoolWithTag(_P, _T)
Definition: module.h:1109
#define IopFreeMdlFromLookaside
Definition: io.h:114
#define MmPrepareMdlForReuse(_Mdl)