trim: Target SCSI UNMAP command instead of WRITE SAME.

* The UNMAP command is theoretically much faster, as it can get many block
  ranges instead of just a single range.
* Furthermore, the ATA TRIM command resembles it much better.
* Therefore, fs_trim_data now gets an array of ranges, and we use SCSI UNMAP
  to trim.
* Updated BFS code to collect array ranges to fully support the new
  fs_trim_data possibilities.

headers/os/drivers/Drivers.h

@@ -172,9 +172,12 @@ typedef struct {
 
 /* B_TRIM_DEVICE data structure */
 typedef struct {
-	off_t	offset;					/* offset (in bytes) */
-	off_t	size;
-	off_t	trimmed_size;			/* filled on return */
+	uint32	range_count;
+	uint64	trimmed_size;			/* filled on return */
+	struct range {
+		uint64	offset;				/* offset (in bytes) */
+		uint64	size;
+	} ranges[1];
 } fs_trim_data;
 
 

headers/private/drivers/scsi_cmds.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2010, 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.
@@ -185,6 +185,8 @@
 #define SCSI_OP_WRITE_BUFFER				0x3b
 #define SCSI_OP_READ_BUFFER					0x3c
 #define SCSI_OP_CHANGE_DEFINITION			0x40
+#define SCSI_OP_WRITE_SAME_10				0x41
+#define SCSI_OP_UNMAP						0x42
 #define SCSI_OP_READ_SUB_CHANNEL			0x42
 #define SCSI_OP_READ_TOC					0x43
 #define SCSI_OP_PLAY_MSF					0x47
@@ -457,7 +459,38 @@ typedef struct scsi_cmd_wsame_16 {
 	);
 	uint8	control;
 } _PACKED scsi_cmd_wsame_16;
-	
+
+
+// UNMAP
+
+typedef struct scsi_cmd_unmap {
+	uint8	opcode;
+	LBITFIELD8_2(
+		anchor : 1,
+		_reserved1_7 : 7
+	);
+	uint32	_reserved1;
+	LBITFIELD8_2(
+		group_number : 5,
+		_reserved5_7 : 3
+	);
+	uint16	length;
+	uint8	control;
+} _PACKED scsi_cmd_unmap;
+
+struct scsi_unmap_block_descriptor {
+	uint64	lba;
+	uint32	block_count;
+	uint32	_reserved1;
+} _PACKED;
+
+struct scsi_unmap_parameter_list {
+	uint16	data_length;
+	uint16	block_data_length;
+	uint32	_reserved1;
+	struct scsi_unmap_block_descriptor blocks[1];
+} _PACKED;
+
 
 // REQUEST SENSE
 

headers/private/drivers/scsi_periph.h

@@ -72,6 +72,10 @@ typedef struct scsi_periph_callbacks {
 	void (*media_changed)(periph_device_cookie cookie, scsi_ccb *request);
 } scsi_periph_callbacks;
 
+typedef struct scsi_block_range {
+	uint64	offset;
+	uint64	size;
+} scsi_block_range;
 
 // functions provided by this module
 typedef struct scsi_periph_interface {
@@ -119,7 +123,7 @@ typedef struct scsi_periph_interface {
 	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);
+		scsi_block_range* ranges, uint32 rangeCount);
 
 	// *** removable media ***
 	// to be called when a medium change is detected to block subsequent commands

headers/private/fs_shell/fssh_drivers.h

@@ -215,9 +215,12 @@ typedef struct {
 
 /* B_TRIM_DEVICE data structure */
 typedef struct {
-	fssh_off_t	offset;					/* offset (in bytes) */
-	fssh_off_t	size;
-	fssh_off_t	trimmed_size;			/* filled on return */
+	uint32_t	range_count;
+	uint64_t	trimmed_size;			/* filled on return */
+	struct range {
+		uint64_t	offset;				/* offset (in bytes) */
+		uint64_t	size;
+	} ranges[1];
 } fssh_fs_trim_data;
 
 

headers/private/kernel/util/fs_trim_support.h

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2013, Axel Dörfler, [email protected].
+ * Distributed under the terms of the MIT license.
+ */
+#ifndef _FS_TRIM_SUPPORT_H
+#define _FS_TRIM_SUPPORT_H
+
+
+#include <Drivers.h>
+
+#include <kernel.h>
+
+
+static inline status_t
+copy_trim_data_from_user(void* buffer, size_t size, fs_trim_data*& _trimData)
+{
+	if (!IS_USER_ADDRESS(buffer))
+		return B_BAD_ADDRESS;
+
+	uint32 count;
+	if (user_memcpy(&count, buffer, sizeof(count)) != B_OK)
+		return B_BAD_ADDRESS;
+
+	size_t bytes = (count - 1) * sizeof(uint64) * 2 + sizeof(fs_trim_data);
+	if (bytes > size)
+		return B_BAD_VALUE;
+
+	void* trimBuffer = malloc(bytes);
+	if (trimBuffer == NULL)
+		return B_NO_MEMORY;
+
+	if (user_memcpy(trimBuffer, buffer, bytes) != B_OK)
+		return B_BAD_ADDRESS;
+
+	_trimData = (fs_trim_data*)trimBuffer;
+	return B_OK;
+}
+
+
+static inline status_t
+copy_trim_data_to_user(void* buffer, fs_trim_data* trimData)
+{
+	// Do not copy any ranges
+	return user_memcpy(buffer, trimData, sizeof(uint64) * 2);
+}
+
+
+#endif	// _FS_TRIM_SUPPORT_H