reactos操作系统实现(104)

AtapiFindPCIController函数是用来发现PCI总线上所有的IDE控制器，并发现相关的IDE设备。具体实现代码如下：

#001 ULONG

#002 NTAPI

#003 AtapiFindPCIController(

#004 IN PVOID HwDeviceExtension,

#005 IN PVOID Context,

#006 IN PVOID BusInformation,

#007 IN PCHAR ArgumentString,

#008 IN OUT PPORT_CONFIGURATION_INFORMATION ConfigInfo,

#009 OUT PBOOLEAN Again

#010 )

#011 /*++

#012

#013 Routine Description:

#014

#015 This function is called by the OS-specific port driver after

#016 the necessary storage has been allocated,to gather information

#017 about the adapter's configuration.

#018

#019 Arguments:

#020

#021 HwDeviceExtension - HBA miniport driver's adapter data storage

#022 Context - Address of adapter count

#023 BusInformation -

#024 ArgumentString - Used to determine whether driver is client of ntldr or crash dump utility.

#025 ConfigInfo - Configuration information structure describing HBA

#026 Again - Indicates search for adapters to continue

#027

#028 Return Value:

#029

#030 ULONG

#031

#032 --*/

#033

#034 {

#035 PHW_DEVICE_EXTENSION deviceExtension = HwDeviceExtension;

#036 PULONG adapterCount = (PULONG)Context;

#037 ULONG channel = 0;

#038 static ULONG functionNumber,

#039 slotNumber,

#040 controllers;

#041 ULONG i,j;

#042 PUCHAR ioSpace;

#043 BOOLEAN atapiOnly,

#044 lastSlot,

#045 controllerFound = FALSE,

#046 deviceFound = FALSE;

#047 UCHAR statusByte;

#048

#049 //

#050 // The following table specifies the ports to be checked when searching for

#051 // an IDE controller. A zero entry terminates the search.

#052 //

#053

这里设置IDE控制器的几个控制端口。

#054 CONST ULONG AdapterAddresses[5] = {0x1F0,0x170,0x1e8,0x168,0};

#055

#056 //

#057 // The following table specifies interrupt levels corresponding to the

#058 // port addresses in the previous table.

#059 //

#060

设置相应的IDE控制器的中断号。

#061 CONST ULONG InterruptLevels[5] = {14,15,11,10,0};

#062

检查设备对象扩展是否分配，如果没有分配，就返回失败。

#063 if (!deviceExtension) {

#064 return SP_RETURN_ERROR;

#065 }

#066

#067 //

#068 // Since scsiport will call this function first before it calls AtapiFindController

#069 // we need to bypass it if we have data installed in ConfigInfo,by the pcmcia driver.

#070 // In that case atapifindcontroller should be called first.

#071 // Instead of modifying atapi driverEntry to search of PCIBus first (now its ISA)

#072 // the check is put here.

#073 //

#074

当总线0上的设备配置不为空时，就进入进找相应的IDE控制器。

#075 if (ScsiPortConvertPhysicalAddressToUlong((*ConfigInfo->AccessRanges)[0].RangeStart) != 0) {

#076

下面调用函数AtapiFindController来发现相应的IDE控制器。

#077 return AtapiFindController(HwDeviceExtension,

#078 Context,

#079 BusInformation,

#080 ArgumentString,

#081 ConfigInfo,

#082 Again);

#083 }

#084

#085

#086 //

#087 // Gronk PCI config space looking for the broken PCI IDE controllers that have only

#088 // one FIFO for both channels.

#089 // Don't do this. It's incorrect and nasty. It has to be done to work around these

#090 // broken parts,no other reason can justify this.

#091 //

#092

下面查找分离的PCI设备配置空间。

#093 for (i = controllers; i < BROKEN_ADAPTERS; i++) {

#094

#095 //

#096 // Determine if both channels are enabled and have devices.

#097 //

#098

#099 lastSlot = FALSE;

#100

#101 if (FindBrokenController(deviceExtension,

#102 (PUCHAR)BrokenAdapters[i].VendorId,

#103 BrokenAdapters[i].VendorIdLength,

#104 (PUCHAR)BrokenAdapters[i].DeviceId,

#105 BrokenAdapters[i].DeviceIdLength,

#106 &functionNumber,

#107 &slotNumber,

#108 ConfigInfo->SystemIoBusNumber,

#109 &lastSlot)) {

#110

#111 slotNumber++;

#112 functionNumber = 0;

#113 controllerFound = TRUE;

#114

#115 DebugPrint((1,

#116 "Found broken PCI IDE controller: VendorId %s,DeviceId %s/n",

#117 BrokenAdapters[i].VendorId,

#118 BrokenAdapters[i].DeviceId));

#119

#120 if (AdapterAddresses[*adapterCount] != 0) {

#121

#122 for (j = 0; j < 2; j++) {

#123

#124 //

#125 // Get the system physical address for this IO range.

#126 //

#127

#128 ioSpace = ScsiPortGetDeviceBase(HwDeviceExtension,

#129 ConfigInfo->AdapterInterfaceType,

#130 ConfigInfo->SystemIoBusNumber,

#131 ScsiPortConvertUlongToPhysicalAddress(AdapterAddresses[*adapterCount]),

#132 8,

#133 TRUE);

#134

#135 //

#136 // Update the adapter count.

#137 //

#138

增加IDE控制器的个数。

#139 (*adapterCount)++;

#140

#141 //

#142 // Check if ioSpace accessible.

#143 //

#144

#145 if (!ioSpace) {

#146 continue;

#147 }

#148

#149 //

#150 // Select master.

#151 //

#152

#153 ScsiPortWritePortUchar(&((PIDE_REGISTERS_1)ioSpace)->DriveSelect,0xA0);

#154

#155 //

#156 // Check if card at this address.

#157 //

#158

#159 ScsiPortWritePortUchar(&((PIDE_REGISTERS_1)ioSpace)->CylinderLow,0xAA);

#160

#161 //

#162 // Check if indentifier can be read back.

#163 //

#164

#165 if ((statusByte = ScsiPortReadPortUchar(&((PIDE_REGISTERS_1)ioSpace)->CylinderLow)) != 0xAA) {

#166

#167 DebugPrint((2,

#168 "AtapiFindPciController: Identifier read back from Master (%x)/n",

#169 statusByte));

#170

#171

#172 //

#173 // Select slave.

#174 //

#175

#176 ScsiPortWritePortUchar(&((PIDE_REGISTERS_1)ioSpace)->DriveSelect,0xB0);

#177

#178 //

#179 // See if slave is present.

#180 //

#181

#182 ScsiPortWritePortUchar(&((PIDE_REGISTERS_1)ioSpace)->CylinderLow,0xAA);

#183

#184 if ((statusByte = ScsiPortReadPortUchar(&((PIDE_REGISTERS_1)ioSpace)->CylinderLow)) != 0xAA) {

#185

#186 DebugPrint((2,

#187 "AtapiFindPciController: Identifier read back from Slave (%x)/n",

#188 statusByte));

#189

#190 //

#191 //

#192 // No controller at this base address.

#193 //

#194

#195 ScsiPortFreeDeviceBase(HwDeviceExtension,

#196 ioSpace);

#197

继续查找第二个通道是否IDE控制器。

#198 //

#199 // If the chip is there,but we couldn't find the primary channel,try the secondary.

#200 // If we couldn't find a secondary,who cares.

#201 //

#202

#203 if (j == 1) {

#204

#205 goto setStatusAndExit;

#206

#207 } else {

#208 continue;

#209 }

#210 }

#211 }

#212

如果发现了IDE控制器，就保存相应的配置参数。

#213 if (controllerFound) {

#214

#215 //

#216 // Record base IO address.

#217 //

#218

#219 deviceExtension->BaseIoAddress1[channel] = (PIDE_REGISTERS_1)(ioSpace);

#220

#221 //

#222 // Fill in the access array information.

#223 //

#224

#225 (*ConfigInfo->AccessRanges)[channel].RangeStart =

#226 ScsiPortConvertUlongToPhysicalAddress(AdapterAddresses[*adapterCount - 1]);

#227

#228 (*ConfigInfo->AccessRanges)[channel].RangeLength = 8;

#229 (*ConfigInfo->AccessRanges)[channel].RangeInMemory = FALSE;

#230

#231 //

#232 // Indicate the interrupt level corresponding to this IO range.

#233 //

#234

根据不同的通道进行保存中断号和中断方式。

#235 if (channel == 0) {

#236 ConfigInfo->BusInterruptLevel = InterruptLevels[*adapterCount - 1];

#237 ConfigInfo->InterruptMode = Latched;

#238 } else {

#239 ConfigInfo->BusInterruptLevel2 = InterruptLevels[*adapterCount - 1];

#240 ConfigInfo->InterruptMode2 = Latched;

#241 }

#242

#243 //

#244 // Get the system physical address for the second IO range.

#245 //

#246

#247 ioSpace = ScsiPortGetDeviceBase(HwDeviceExtension,

#248 ConfigInfo->AdapterInterfaceType,

#249 ConfigInfo->SystemIoBusNumber,

#250 ScsiPortConvertUlongToPhysicalAddress(AdapterAddresses[*adapterCount - 1] + 0x206),

#251 1,

#252 TRUE);

#253

#254 deviceExtension->BaseIoAddress2[channel] = (PIDE_REGISTERS_2)(ioSpace);

#255

#256 deviceExtension->NumberChannels = 2;

#257

#258 //

#259 // Indicate only one bus.

#260 //

#261

#262 ConfigInfo->NumberOfBuses = 1;

#263

#264 //

#265 // Indicate four devices can be attached to the adapter,since we

#266 // have to serialize access to the two channels.

#267 //

#268

#269 ConfigInfo->MaximumNumberOfTargets = 4;

#270

#271 //

#272 // Indicate maximum transfer length is 64k.

#273 //

#274

#275 ConfigInfo->MaximumTransferLength = 0x10000;

#276

#277 DebugPrint((1,

#278 "AtapiFindPciController: Found broken IDE at %x/n",

#279 deviceExtension->BaseIoAddress1[channel]));

#280

#281 //

#282 // Since we will always pick up this part,and not atdisk,so indicate.

#283 //

#284

#285 atapiOnly = FALSE;

#286

保存中断模式。

#287 //

#288 // Save the Interrupe Mode for later use

#289 //

#290 deviceExtension->InterruptMode = ConfigInfo->InterruptMode;

#291

查找这个IDE控制器上所有的设备。

#292 //

#293 // Search for devices on this controller.

#294 //

#295

#296 if (FindDevices(HwDeviceExtension,

#297 atapiOnly,

#298 channel++)){

#299 deviceFound = TRUE;

#300 }

#301

判断是主IDE设备，还第二个IDE设备。

#302 //

#303 // Claim primary or secondary ATA IO range.

#304 //

#305

#306 if (*adapterCount == 1) {

#307 ConfigInfo->AtdiskPrimaryClaimed = TRUE;

#308 deviceExtension->PrimaryAddress = TRUE;

#309

#310 } else if (*adapterCount == 2) {

#311 ConfigInfo->AtdiskSecondaryClaimed = TRUE;

#312 deviceExtension->PrimaryAddress = FALSE;

#313 }

#314 }

#315 }

#316 }

#317 }

#318

#319 setStatusAndExit:

#320

#321 if (lastSlot) {

#322 slotNumber = 0;

#323 functionNumber = 0;

#324 }

#325

#326 controllers = i;

#327

#328 if (controllerFound && deviceFound) {

#329

返回已经搜索到设备。

#330 *Again = TRUE;

#331 return SP_RETURN_FOUND;

#332 }

#333 }

#334

#335

已经搜索完成，没有任设备发现。

#336 //

#337 // The entire table has been searched and no adapters have been found.

#338 //

#339

#340 *Again = FALSE;

#341

#342 return SP_RETURN_NOT_FOUND;

#343

#344} // end AtapiFindPCIController()

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