block: Add driver for Micron RealSSD pcie flash cards

This adds mtip32xx, a driver supporting Microns line of
pci-express flash storage cards.
Signed-off-by: NAsai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: NSam Bradshaw <sbradshaw@micron.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

drivers/block/Kconfig

@@ -116,6 +116,8 @@ config PARIDE
 
 source "drivers/block/paride/Kconfig"
 
+source "drivers/block/mtip32xx/Kconfig"
+
 config BLK_CPQ_DA
 	tristate "Compaq SMART2 support"
 	depends on PCI && VIRT_TO_BUS

drivers/block/Makefile

@@ -39,5 +39,6 @@ obj-$(CONFIG_XEN_BLKDEV_FRONTEND)	+= xen-blkfront.o
 obj-$(CONFIG_XEN_BLKDEV_BACKEND)	+= xen-blkback/
 obj-$(CONFIG_BLK_DEV_DRBD)     += drbd/
 obj-$(CONFIG_BLK_DEV_RBD)     += rbd.o
+obj-$(CONFIG_BLK_DEV_PCIESSD_MTIP32XX)	+= mtip32xx/
 
 swim_mod-y	:= swim.o swim_asm.o

drivers/block/mtip32xx/Kconfig

+#
+# mtip32xx device driver configuration
+#
+
+config BLK_DEV_PCIESSD_MTIP32XX
+	tristate "Block Device Driver for Micron PCIe SSDs"
+	depends on HOTPLUG_PCI_PCIE
+	help
+          This enables the block driver for Micron PCIe SSDs.

drivers/block/mtip32xx/Makefile

+#
+# Makefile for  Block device driver for Micron PCIe SSD
+#
+
+obj-$(CONFIG_BLK_DEV_PCIESSD_MTIP32XX) += mtip32xx.o

drivers/block/mtip32xx/mtip32xx.h

+/*
+ * mtip32xx.h - Header file for the P320 SSD Block Driver
+ *   Copyright (C) 2011 Micron Technology, Inc.
+ *
+ * Portions of this code were derived from works subjected to the
+ * following copyright:
+ *    Copyright (C) 2009 Integrated Device Technology, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef __MTIP32XX_H__
+#define __MTIP32XX_H__
+
+#include <linux/spinlock.h>
+#include <linux/rwsem.h>
+#include <linux/ata.h>
+#include <linux/interrupt.h>
+#include <linux/genhd.h>
+#include <linux/version.h>
+
+/* Offset of Subsystem Device ID in pci confoguration space */
+#define PCI_SUBSYSTEM_DEVICEID	0x2E
+
+/* offset of Device Control register in PCIe extended capabilites space */
+#define PCIE_CONFIG_EXT_DEVICE_CONTROL_OFFSET	0x48
+
+/* # of times to retry timed out IOs */
+#define MTIP_MAX_RETRIES	5
+
+/* Various timeout values in ms */
+#define MTIP_NCQ_COMMAND_TIMEOUT_MS       5000
+#define MTIP_IOCTL_COMMAND_TIMEOUT_MS     5000
+#define MTIP_INTERNAL_COMMAND_TIMEOUT_MS  5000
+
+/* check for timeouts every 500ms */
+#define MTIP_TIMEOUT_CHECK_PERIOD	500
+
+/* ftl rebuild */
+#define MTIP_FTL_REBUILD_OFFSET		142
+#define MTIP_FTL_REBUILD_MAGIC		0xed51
+#define MTIP_FTL_REBUILD_TIMEOUT_MS	2400000
+
+/* Macro to extract the tag bit number from a tag value. */
+#define MTIP_TAG_BIT(tag)	(tag & 0x1f)
+
+/*
+ * Macro to extract the tag index from a tag value. The index
+ * is used to access the correct s_active/Command Issue register based
+ * on the tag value.
+ */
+#define MTIP_TAG_INDEX(tag)	(tag >> 5)
+
+/*
+ * Maximum number of scatter gather entries
+ * a single command may have.
+ */
+#define MTIP_MAX_SG		128
+
+/*
+ * Maximum number of slot groups (Command Issue & s_active registers)
+ * NOTE: This is the driver maximum; check dd->slot_groups for actual value.
+ */
+#define MTIP_MAX_SLOT_GROUPS	8
+
+/* Internal command tag. */
+#define MTIP_TAG_INTERNAL	0
+
+/* Micron Vendor ID & P320x SSD Device ID */
+#define PCI_VENDOR_ID_MICRON    0x1344
+#define P320_DEVICE_ID		0x5150
+
+/* Driver name and version strings */
+#define MTIP_DRV_NAME		"mtip32xx"
+#define MTIP_DRV_VERSION	"1.2.6os2"
+
+/* Maximum number of minor device numbers per device. */
+#define MTIP_MAX_MINORS		16
+
+/* Maximum number of supported command slots. */
+#define MTIP_MAX_COMMAND_SLOTS	(MTIP_MAX_SLOT_GROUPS * 32)
+
+/*
+ * Per-tag bitfield size in longs.
+ * Linux bit manipulation functions
+ * (i.e. test_and_set_bit, find_next_zero_bit)
+ * manipulate memory in longs, so we try to make the math work.
+ * take the slot groups and find the number of longs, rounding up.
+ * Careful! i386 and x86_64 use different size longs!
+ */
+#define U32_PER_LONG	(sizeof(long) / sizeof(u32))
+#define SLOTBITS_IN_LONGS ((MTIP_MAX_SLOT_GROUPS + \
+					(U32_PER_LONG-1))/U32_PER_LONG)
+
+/* BAR number used to access the HBA registers. */
+#define MTIP_ABAR		5
+
+/* Forced Unit Access Bit */
+#define FUA_BIT			0x80
+
+#ifdef DEBUG
+ #define dbg_printk(format, arg...)	\
+	printk(pr_fmt(format), ##arg);
+#else
+ #define dbg_printk(format, arg...)
+#endif
+
+/* Register Frame Information Structure (FIS), host to device. */
+struct host_to_dev_fis {
+	/*
+	 * FIS type.
+	 * - 27h Register FIS, host to device.
+	 * - 34h Register FIS, device to host.
+	 * - 39h DMA Activate FIS, device to host.
+	 * - 41h DMA Setup FIS, bi-directional.
+	 * - 46h Data FIS, bi-directional.
+	 * - 58h BIST Activate FIS, bi-directional.
+	 * - 5Fh PIO Setup FIS, device to host.
+	 * - A1h Set Device Bits FIS, device to host.
+	 */
+	unsigned char type;
+	unsigned char opts;
+	unsigned char command;
+	unsigned char features;
+
+	union {
+		unsigned char lba_low;
+		unsigned char sector;
+	};
+	union {
+		unsigned char lba_mid;
+		unsigned char cyl_low;
+	};
+	union {
+		unsigned char lba_hi;
+		unsigned char cyl_hi;
+	};
+	union {
+		unsigned char device;
+		unsigned char head;
+	};
+
+	union {
+		unsigned char lba_low_ex;
+		unsigned char sector_ex;
+	};
+	union {
+		unsigned char lba_mid_ex;
+		unsigned char cyl_low_ex;
+	};
+	union {
+		unsigned char lba_hi_ex;
+		unsigned char cyl_hi_ex;
+	};
+	unsigned char features_ex;
+
+	unsigned char sect_count;
+	unsigned char sect_cnt_ex;
+	unsigned char res2;
+	unsigned char control;
+
+	unsigned int res3;
+};
+
+/* Command header structure. */
+struct mtip_cmd_hdr {
+	/*
+	 * Command options.
+	 * - Bits 31:16 Number of PRD entries.
+	 * - Bits 15:8 Unused in this implementation.
+	 * - Bit 7 Prefetch bit, informs the drive to prefetch PRD entries.
+	 * - Bit 6 Write bit, should be set when writing data to the device.
+	 * - Bit 5 Unused in this implementation.
+	 * - Bits 4:0 Length of the command FIS in DWords (DWord = 4 bytes).
+	 */
+	unsigned int opts;
+	/* This field is unsed when using NCQ. */
+	union {
+		unsigned int byte_count;
+		unsigned int status;
+	};
+	/*
+	 * Lower 32 bits of the command table address associated with this
+	 * header. The command table addresses must be 128 byte aligned.
+	 */
+	unsigned int ctba;
+	/*
+	 * If 64 bit addressing is used this field is the upper 32 bits
+	 * of the command table address associated with this command.
+	 */
+	unsigned int ctbau;
+	/* Reserved and unused. */
+	unsigned int res[4];
+};
+
+/* Command scatter gather structure (PRD). */
+struct mtip_cmd_sg {
+	/*
+	 * Low 32 bits of the data buffer address. For P320 this
+	 * address must be 8 byte aligned signified by bits 2:0 being
+	 * set to 0.
+	 */
+	unsigned int dba;
+	/*
+	 * When 64 bit addressing is used this field is the upper
+	 * 32 bits of the data buffer address.
+	 */
+	unsigned int dba_upper;
+	/* Unused. */
+	unsigned int reserved;
+	/*
+	 * Bit 31: interrupt when this data block has been transferred.
+	 * Bits 30..22: reserved
+	 * Bits 21..0: byte count (minus 1).  For P320 the byte count must be
+	 * 8 byte aligned signified by bits 2:0 being set to 1.
+	 */
+	unsigned int info;
+};
+struct mtip_port;
+
+/* Structure used to describe a command. */
+struct mtip_cmd {
+
+	struct mtip_cmd_hdr *command_header; /* ptr to command header entry */
+
+	dma_addr_t command_header_dma; /* corresponding physical address */
+
+	void *command; /* ptr to command table entry */
+
+	dma_addr_t command_dma; /* corresponding physical address */
+
+	void *comp_data; /* data passed to completion function comp_func() */
+	/*
+	 * Completion function called by the ISR upon completion of
+	 * a command.
+	 */
+	void (*comp_func)(struct mtip_port *port,
+				int tag,
+				void *data,
+				int status);
+	/* Additional callback function that may be called by comp_func() */
+	void (*async_callback)(void *data, int status);
+
+	void *async_data; /* Addl. data passed to async_callback() */
+
+	int scatter_ents; /* Number of scatter list entries used */
+
+	struct scatterlist sg[MTIP_MAX_SG]; /* Scatter list entries */
+
+	int retries; /* The number of retries left for this command. */
+
+	int direction; /* Data transfer direction */
+
+	unsigned long comp_time; /* command completion time, in jiffies */
+
+	atomic_t active; /* declares if this command sent to the drive.  */
+};
+
+/* Structure used to describe a port. */
+struct mtip_port {
+	/* Pointer back to the driver data for this port. */
+	struct driver_data *dd;
+	/*
+	 * Used to determine if the data pointed to by the
+	 * identify field is valid.
+	 */
+	unsigned long identify_valid;
+	/* Base address of the memory mapped IO for the port. */
+	void __iomem *mmio;
+	/* Array of pointers to the memory mapped s_active registers. */
+	void __iomem *s_active[MTIP_MAX_SLOT_GROUPS];
+	/* Array of pointers to the memory mapped completed registers.  */
+	void __iomem *completed[MTIP_MAX_SLOT_GROUPS];
+	/* Array of pointers to the memory mapped Command Issue registers. */
+	void __iomem *cmd_issue[MTIP_MAX_SLOT_GROUPS];
+	/*
+	 * Pointer to the beginning of the command header memory as used
+	 * by the driver.
+	 */
+	void *command_list;
+	/*
+	 * Pointer to the beginning of the command header memory as used
+	 * by the DMA.
+	 */
+	dma_addr_t command_list_dma;
+	/*
+	 * Pointer to the beginning of the RX FIS memory as used
+	 * by the driver.
+	 */
+	void *rxfis;
+	/*
+	 * Pointer to the beginning of the RX FIS memory as used
+	 * by the DMA.
+	 */
+	dma_addr_t rxfis_dma;
+	/*
+	 * Pointer to the beginning of the command table memory as used
+	 * by the driver.
+	 */
+	void *command_table;
+	/*
+	 * Pointer to the beginning of the command table memory as used
+	 * by the DMA.
+	 */
+	dma_addr_t command_tbl_dma;
+	/*
+	 * Pointer to the beginning of the identify data memory as used
+	 * by the driver.
+	 */
+	u16 *identify;
+	/*
+	 * Pointer to the beginning of the identify data memory as used
+	 * by the DMA.
+	 */
+	dma_addr_t identify_dma;
+	/*
+	 * Pointer to the beginning of a sector buffer that is used
+	 * by the driver when issuing internal commands.
+	 */
+	u16 *sector_buffer;
+	/*
+	 * Pointer to the beginning of a sector buffer that is used
+	 * by the DMA when the driver issues internal commands.
+	 */
+	dma_addr_t sector_buffer_dma;
+	/*
+	 * Bit significant, used to determine if a command slot has
+	 * been allocated. i.e. the slot is in use.  Bits are cleared
+	 * when the command slot and all associated data structures
+	 * are no longer needed.
+	 */
+	unsigned long allocated[SLOTBITS_IN_LONGS];
+	/*
+	 * Array of command slots. Structure includes pointers to the
+	 * command header and command table, and completion function and data
+	 * pointers.
+	 */
+	struct mtip_cmd commands[MTIP_MAX_COMMAND_SLOTS];
+	/* Non-zero if an internal command is in progress. */
+	int internal_cmd_in_progress;
+	/*
+	 * Timer used to complete commands that have been active for too long.
+	 */
+	struct timer_list cmd_timer;
+	/*
+	 * Semaphore used to block threads if there are no
+	 * command slots available.
+	 */
+	struct semaphore cmd_slot;
+	/* Spinlock for working around command-issue bug. */
+	spinlock_t cmd_issue_lock;
+};
+
+/*
+ * Driver private data structure.
+ *
+ * One structure is allocated per probed device.
+ */
+struct driver_data {
+	void __iomem *mmio; /* Base address of the HBA registers. */
+
+	int major; /* Major device number. */
+
+	int instance; /* Instance number. First device probed is 0, ... */
+
+	int protocol; /* FIXME: Protocol ops array index. */
+
+	struct gendisk *disk; /* Pointer to our gendisk structure. */
+
+	struct pci_dev *pdev; /* Pointer to the PCI device structure. */
+
+	struct request_queue *queue; /* Our request queue. */
+	/*
+	 * Semaphore used to lock out read/write commands during the
+	 * execution of an internal command.
+	 */
+	struct rw_semaphore internal_sem;
+
+	struct mtip_port *port; /* Pointer to the port data structure. */
+
+	/* Tasklet used to process the bottom half of the ISR. */
+	struct tasklet_struct tasklet;
+
+	unsigned product_type; /* magic value declaring the product type */
+
+	unsigned slot_groups; /* number of slot groups the product supports */
+
+	atomic_t drv_cleanup_done; /* Atomic variable for SRSI */
+
+	unsigned long index; /* Index to determine the disk name */
+
+	unsigned int ftlrebuildflag; /* FTL rebuild flag */
+
+	atomic_t resumeflag; /* Atomic variable to track suspend/resume */
+
+	atomic_t eh_active; /* Flag for error handling tracking */
+};
+
+/* Function declarations */
+extern int mtip_block_initialize(struct driver_data *dd);
+extern int mtip_block_remove(struct driver_data *dd);
+extern int mtip_block_shutdown(struct driver_data *dd);
+extern int mtip_block_suspend(struct driver_data *dd);
+extern int mtip_block_resume(struct driver_data *dd);
+extern int mtip_hw_init(struct driver_data *dd);
+extern int mtip_hw_exit(struct driver_data *dd);
+extern int mtip_hw_shutdown(struct driver_data *dd);
+extern bool mtip_hw_get_capacity(struct driver_data *dd, sector_t *sectors);
+extern void mtip_hw_release_scatterlist(
+			struct driver_data *dd,
+			int tag);
+extern struct scatterlist *mtip_hw_get_scatterlist(
+			struct driver_data *dd,
+			int *tag);
+extern void mtip_hw_submit_io(struct driver_data *dd,
+			sector_t start,
+			int nsect,
+			int nents,
+			int tag,
+			void *callback,
+			void *data,
+			int barrier,
+			int dir);
+extern int mtip_hw_ioctl(struct driver_data *dd,
+			unsigned int cmd,
+			unsigned long arg,
+			unsigned char compat);
+extern int mtip_hw_sysfs_init(struct driver_data *dd, struct kobject *kobj);
+extern int mtip_hw_sysfs_exit(struct driver_data *dd, struct kobject *kobj);
+extern int mtip_hw_resume(struct driver_data *dd);
+extern int mtip_hw_suspend(struct driver_data *dd);
+void mtip_command_cleanup(struct driver_data *dd);
+bool mtip_check_surprise_removal(struct pci_dev *pdev);
+void mtip_restart_port(struct mtip_port *port);
+
+#endif