This gets the trim command as WRITE SAME operation to SCSI

* Neither hardware nor driver to test it; AHCI/IDE support is next
  on the table.

headers/private/drivers/scsi_periph.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2008, Haiku, Inc. All RightsReserved.
+ * Copyright 2004-2013, Haiku, Inc. All RightsReserved.
  * Copyright 2002/03, Thomas Kurschel. All rights reserved.
  *
  * Distributed under the terms of the MIT License.
@@ -7,6 +7,7 @@
 #ifndef _SCSI_PERIPH_H
 #define _SCSI_PERIPH_H
 
+
 /*!	Use this module to minimize work required to write a SCSI
 	peripheral driver.
 
@@ -114,6 +115,12 @@ typedef struct scsi_periph_interface {
 	// request - ccb for this device; is used to talk to device
 	status_t (*check_capacity)(scsi_periph_device device, scsi_ccb *request);
 
+	// synchronizes (flush) the device cache
+	err_res (*synchronize_cache)(scsi_periph_device device, scsi_ccb *request);
+
+	status_t (*trim_device)(scsi_periph_device_info *device, scsi_ccb *request,
+		uint64 offset, uint64 numBlocks);
+
 	// *** removable media ***
 	// to be called when a medium change is detected to block subsequent commands
 	void (*media_changed)(scsi_periph_device device);
@@ -128,8 +135,6 @@ typedef struct scsi_periph_interface {
 	// returns: B_OK, B_DEV_MEDIA_CHANGE_REQUESTED, B_NO_MEMORY or
 	// pending error reported by handle_get_error
 	status_t (*get_media_status)(scsi_periph_handle handle);
-	// synchronizes (flush) the device cache
-	err_res(*synchronize_cache)(scsi_periph_device device, scsi_ccb *request);
 
 	// compose device name consisting of prefix and path/target/LUN
 	// (result must be freed by caller)

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

@@ -1,9 +1,10 @@
 /*
- * Copyright 2008-2012, Axel Dörfler, [email protected].
+ * Copyright 2008-2013, Axel Dörfler, [email protected].
  * Copyright 2002/03, Thomas Kurschel. All rights reserved.
  * Distributed under the terms of the MIT License.
  */
 
+
 /*!	Peripheral driver to handle any kind of SCSI disks,
 	i.e. hard disk and floopy disks (ZIP etc.)
 
@@ -93,7 +94,6 @@ get_geometry(das_handle* handle, device_geometry* geometry)
 	if (status != B_OK)
 		return status;
 
-
 	devfs_compute_geometry_size(geometry, info->capacity, info->block_size);
 
 	geometry->device_type = B_DISK;
@@ -153,6 +153,24 @@ synchronize_cache(das_driver_info *device)
 }
 
 
+static status_t
+trim_device(das_driver_info* device, off_t offset, off_t size)
+{
+	TRACE("trim_device()\n");
+
+	scsi_ccb* request = device->scsi->alloc_ccb(device->scsi_device);
+	if (request == NULL)
+		return B_NO_MEMORY;
+
+	status_t status = sSCSIPeripheral->trim_device(device->scsi_periph_device,
+		request, offset / device->block_size, size / device->block_size);
+
+	device->scsi->free_ccb(request);
+
+	return status;
+}
+
+
 static int
 log2(uint32 x)
 {
@@ -385,6 +403,21 @@ das_ioctl(void* cookie, uint32 op, void* buffer, size_t length)
 		case B_FLUSH_DRIVE_CACHE:
 			return synchronize_cache(info);
 
+		case B_TRIM_DEVICE:
+		{
+			fs_trim_data trimData;
+			if (user_memcpy(&trimData, buffer, sizeof(fs_trim_data)) != B_OK)
+				return B_BAD_ADDRESS;
+
+			status_t status = trim_device(info, trimData.offset, trimData.size);
+			if (status != B_OK)
+				return status;
+
+			trimData.trimmed_size = trimData.size;
+
+			return user_memcpy(buffer, &trimData, sizeof(fs_trim_data));
+		}
+
 		default:
 			return sSCSIPeripheral->ioctl(handle->scsi_periph_handle, op,
 				buffer, length);
@@ -649,7 +682,7 @@ struct driver_module_info sSCSIDiskDriver = {
 	das_init_driver,
 	das_uninit_driver,
 	das_register_child_devices,
-	das_rescan_child_devices,	
+	das_rescan_child_devices,
 	NULL,	// removed
 };
 

src/add-ons/kernel/generic/scsi_periph/block.cpp

@@ -1,12 +1,12 @@
 /*
- * Copyright 2004-2011, Haiku, Inc. All RightsReserved.
+ * Copyright 2004-2013, Haiku, Inc. All RightsReserved.
  * Copyright 2002-2003, Thomas Kurschel. All rights reserved.
  *
  * Distributed under the terms of the MIT License.
  */
 
 
-//!	Handling of block device (currently, only a capacity check is provided)
+//!	Handling of block device
 
 
 #include "scsi_periph_int.h"
@@ -59,10 +59,10 @@ periph_check_capacity(scsi_periph_device_info *device, scsi_ccb *request)
 
 		if (capacity == UINT_MAX) {
 			mutex_unlock(&device->mutex);
-			
+
 			scsi_cmd_read_capacity_long *cmd
 				= (scsi_cmd_read_capacity_long *)request->cdb;
-			
+
 			scsi_res_read_capacity_long capacityLongResult;
 			request->data = (uint8*)&capacityLongResult;
 			request->data_length = sizeof(capacityLongResult);
@@ -114,3 +114,42 @@ periph_check_capacity(scsi_periph_device_info *device, scsi_ccb *request)
 	return res;
 }
 
+
+status_t
+periph_trim_device(scsi_periph_device_info *device, scsi_ccb *request,
+	uint64 offset, uint64 numBlocks)
+{
+	err_res res;
+	int retries = 0;
+
+	do {
+		request->flags = SCSI_DIR_OUT;
+		request->sort = offset;
+		request->timeout = device->std_timeout;
+
+		scsi_cmd_wsame_16* cmd = (scsi_cmd_wsame_16*)request->cdb;
+
+		memset(cmd, 0, sizeof(*cmd));
+		cmd->opcode = SCSI_OP_WRITE_SAME_16;
+		cmd->unmap = 1;
+		cmd->lba = B_HOST_TO_BENDIAN_INT64(offset);
+		cmd->length = B_HOST_TO_BENDIAN_INT32(numBlocks);
+
+		request->cdb_length = sizeof(*cmd);
+
+		device->scsi->async_io(request);
+
+		acquire_sem(request->completion_sem);
+
+		// ask generic peripheral layer what to do now
+		res = periph_check_error(device, request);
+	} while ((res.action == err_act_retry && retries++ < 3)
+		|| (res.action == err_act_many_retries && retries++ < 30));
+
+	// peripheral layer only creates "read" error
+	if (res.error_code == B_DEV_READ_ERROR)
+		return B_DEV_WRITE_ERROR;
+
+	return res.error_code;
+}
+

src/add-ons/kernel/generic/scsi_periph/scsi_periph.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2008, Haiku, Inc. All RightsReserved.
+ * Copyright 2004-2013, Haiku, Inc. All RightsReserved.
  * Copyright 2002-2003, Thomas Kurschel. All rights reserved.
  *
  * Distributed under the terms of the MIT License.
@@ -135,12 +135,13 @@ static scsi_periph_interface sSCSIPeripheralModule = {
 	periph_io,
 	periph_ioctl,
 	periph_check_capacity,
+	periph_synchronize_cache,
+	periph_trim_device,
 
 	periph_media_changed_public,
 	periph_check_error,
 	periph_send_start_stop,
 	periph_get_media_status,
-	periph_synchronize_cache,
 
 	periph_compose_device_name
 };

src/add-ons/kernel/generic/scsi_periph/scsi_periph_int.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2008, Haiku, Inc. All Rights Reserved.
+ * Copyright 2004-2013, Haiku, Inc. All Rights Reserved.
  * Copyright 2002, Thomas Kurschel. All rights reserved.
  * Distributed under the terms of the MIT License.
  */
@@ -77,6 +77,8 @@ status_t periph_handle_free(scsi_periph_handle_info *handle);
 // block.c
 
 status_t periph_check_capacity(scsi_periph_device_info *device, scsi_ccb *ccb);
+status_t periph_trim_device(scsi_periph_device_info *device, scsi_ccb *request,
+	uint64 offset, uint64 numBlocks);
 
 
 // device.c