AbstractModuleDevice: Add generic read/write hooks via "io" hook.

This substitutes for the already-existing behavior of scsi_cd, scsi_disk,
and virtio_block, so we can delete their hooks and let them use
these new generic fallbacks.

Some other drivers perform clamping, and so using these fallbacks would
constitute a behavioral change.

Change-Id: I9a2e503f2e03abc276bdfc02d1cff1565a9742e9

src/add-ons/kernel/drivers/disk/scsi/scsi_cd/scsi_cd.cpp

@@ -761,46 +761,6 @@ cd_io(void* cookie, io_request* request)
 }
 
 
-static status_t
-cd_read(void* cookie, off_t pos, void* buffer, size_t* _length)
-{
-	size_t length = *_length;
-
-	IORequest request;
-	status_t status = request.Init(pos, (addr_t)buffer, length, false, 0);
-	if (status != B_OK)
-		return status;
-
-	status = cd_io(cookie, &request);
-	if (status != B_OK)
-		return status;
-
-	status = request.Wait(0, 0);
-	*_length = request.TransferredBytes();
-	return status;
-}
-
-
-static status_t
-cd_write(void* cookie, off_t pos, const void* buffer, size_t* _length)
-{
-	size_t length = *_length;
-
-	IORequest request;
-	status_t status = request.Init(pos, (addr_t)buffer, length, true, 0);
-	if (status != B_OK)
-		return status;
-
-	status = cd_io(cookie, &request);
-	if (status != B_OK)
-		return status;
-
-	status = request.Wait(0, 0);
-	*_length = request.TransferredBytes();
-	return status;
-}
-
-
 static status_t
 cd_ioctl(void* cookie, uint32 op, void* buffer, size_t length)
 {
@@ -1186,8 +1146,8 @@ struct device_module_info sSCSICDDevice = {
 	cd_open,
 	cd_close,
 	cd_free,
-	cd_read,
+	NULL,	// read
-	cd_write,
+	NULL,	// write
 	cd_io,
 	cd_ioctl,
 

src/add-ons/kernel/drivers/disk/scsi/scsi_disk/scsi_disk.cpp

@@ -325,54 +325,6 @@ das_free(void* cookie)
 }
 
 
-static status_t
-das_read(void* cookie, off_t pos, void* buffer, size_t* _length)
-{
-	das_handle* handle = (das_handle*)cookie;
-	size_t length = *_length;
-
-	IORequest request;
-	status_t status = request.Init(pos, (addr_t)buffer, length, false, 0);
-	if (status != B_OK)
-		return status;
-
-	status = handle->info->io_scheduler->ScheduleRequest(&request);
-	if (status != B_OK)
-		return status;
-
-	status = request.Wait(0, 0);
-	*_length = request.TransferredBytes();
-	if (status != B_OK)
-		dprintf("das_read: request.Wait() returned: %s\n", strerror(status));
-
-	return status;
-}
-
-
-static status_t
-das_write(void* cookie, off_t pos, const void* buffer, size_t* _length)
-{
-	das_handle* handle = (das_handle*)cookie;
-	size_t length = *_length;
-
-	IORequest request;
-	status_t status = request.Init(pos, (addr_t)buffer, length, true, 0);
-	if (status != B_OK)
-		return status;
-
-	status = handle->info->io_scheduler->ScheduleRequest(&request);
-	if (status != B_OK)
-		return status;
-
-	status = request.Wait(0, 0);
-	*_length = request.TransferredBytes();
-	if (status != B_OK)
-		dprintf("das_write: request.Wait() returned: %s\n", strerror(status));
-
-	return status;
-}
-
-
 static status_t
 das_io(void *cookie, io_request *request)
 {
@@ -702,8 +654,8 @@ struct device_module_info sSCSIDiskDevice = {
 	das_open,
 	das_close,
 	das_free,
-	das_read,
+	NULL,	// read
-	das_write,
+	NULL,	// write
 	das_io,
 	das_ioctl,
 

src/add-ons/kernel/drivers/disk/virtual/virtio_block/virtio_block.cpp

@@ -335,57 +335,6 @@ virtio_block_free(void* cookie)
 }
 
 
-static status_t
-virtio_block_read(void* cookie, off_t pos, void* buffer, size_t* _length)
-{
-	CALLED();
-	virtio_block_handle* handle = (virtio_block_handle*)cookie;
-	size_t length = *_length;
-
-	IORequest request;
-	status_t status = request.Init(pos, (addr_t)buffer, length, false, 0);
-	if (status != B_OK)
-		return status;
-
-	status = handle->info->io_scheduler->ScheduleRequest(&request);
-	if (status != B_OK)
-		return status;
-
-	status = request.Wait(0, 0);
-	*_length = request.TransferredBytes();
-	if (status != B_OK)
-		dprintf("virtio_block_read: request.Wait() returned: %s\n", strerror(status));
-
-	return status;
-}
-
-
-static status_t
-virtio_block_write(void* cookie, off_t pos, const void* buffer,
-	size_t* _length)
-{
-	CALLED();
-	virtio_block_handle* handle = (virtio_block_handle*)cookie;
-	size_t length = *_length;
-
-	IORequest request;
-	status_t status = request.Init(pos, (addr_t)buffer, length, true, 0);
-	if (status != B_OK)
-		return status;
-
-	status = handle->info->io_scheduler->ScheduleRequest(&request);
-	if (status != B_OK)
-		return status;
-
-	status = request.Wait(0, 0);
-	*_length = request.TransferredBytes();
-	if (status != B_OK)
-		dprintf("virtio_block_write: request.Wait() returned: %s\n", strerror(status));
-
-	return status;
-}
-
-
 static status_t
 virtio_block_io(void *cookie, io_request *request)
 {
@@ -655,8 +604,8 @@ struct device_module_info sVirtioBlockDevice = {
 	virtio_block_open,
 	virtio_block_close,
 	virtio_block_free,
-	virtio_block_read,
+	NULL,	// read
-	virtio_block_write,
+	NULL,	// write
 	virtio_block_io,
 	virtio_block_ioctl,
 

src/system/kernel/device_manager/AbstractModuleDevice.cpp

@@ -7,6 +7,8 @@
 
 #include "AbstractModuleDevice.h"
 
+#include "IORequest.h"
+
 
 AbstractModuleDevice::AbstractModuleDevice()
 	:
@@ -65,11 +67,34 @@ AbstractModuleDevice::Open(const char* path, int openMode, void** _cookie)
 }
 
 
+status_t
+AbstractModuleDevice::_DoIO(void* cookie, off_t pos,
+	void* buffer, size_t* _length, bool isWrite)
+{
+	IORequest request;
+	status_t status = request.Init(pos, (addr_t)buffer, *_length, isWrite, 0);
+	if (status != B_OK)
+		return status;
+
+	status = IO(cookie, &request);
+	if (status != B_OK)
+		return status;
+
+	status = request.Wait(0, 0);
+	*_length = request.TransferredBytes();
+	return status;
+}
+
+
 status_t
 AbstractModuleDevice::Read(void* cookie, off_t pos, void* buffer, size_t* _length)
 {
-	if (Module()->read == NULL)
+	if (Module()->read == NULL) {
+		if (Module()->io == NULL)
 			return BaseDevice::Read(cookie, pos, buffer, _length);
+
+		return _DoIO(cookie, pos, buffer, _length, false);
+	}
 	return Module()->read(cookie, pos, buffer, _length);
 }
 
@@ -77,8 +102,12 @@ AbstractModuleDevice::Read(void* cookie, off_t pos, void* buffer, size_t* _lengt
 status_t
 AbstractModuleDevice::Write(void* cookie, off_t pos, const void* buffer, size_t* _length)
 {
-	if (Module()->write == NULL)
+	if (Module()->write == NULL) {
+		if (Module()->io == NULL)
 			return BaseDevice::Write(cookie, pos, buffer, _length);
+
+		return _DoIO(cookie, pos, const_cast<void*>(buffer), _length, true);
+	}
 	return Module()->write(cookie, pos, buffer, _length);
 }
 

src/system/kernel/device_manager/AbstractModuleDevice.h

@@ -45,6 +45,10 @@ public:
 	virtual	status_t		Close(void* cookie);
 	virtual	status_t		Free(void* cookie);
 
+protected:
+			status_t 		_DoIO(void* cookie, off_t pos,
+								void* buffer, size_t* _length, bool isWrite);
+
 protected:
 	device_node*			fNode;
 	int32					fInitialized;