block: IBM RamSan 70/80 device driver

This patch includes the device driver for the IBM RamSan
family of PCI SSD flash storage cards. This driver will
include support for the RamSan 70 and 80. The driver
presents a block device for device I/O.

Signed-off-by: Philip J Kelleher <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

MAINTAINERS

@@ -6306,6 +6306,12 @@ S:	Maintained
 F:	Documentation/blockdev/ramdisk.txt
 F:	drivers/block/brd.c
 
+RAMSAM DRIVER (IBM RamSan 70/80 PCI SSD Flash Card)
+M:	Joshua Morris <[email protected]>
+M:	Philip Kelleher <[email protected]>
+S:	Maintained
+F:	drivers/block/rsxx/
+
 RANDOM NUMBER DRIVER
 M:	Theodore Ts'o" <[email protected]>
 S:	Maintained

drivers/block/Kconfig

@@ -544,4 +544,14 @@ config BLK_DEV_RBD
 
 	  If unsure, say N.
 
+config BLK_DEV_RSXX
+	tristate "RamSam PCIe Flash SSD Device Driver"
+	depends on PCI
+	help
+	  Device driver for IBM's high speed PCIe SSD
+	  storage devices: RamSan-70 and RamSan-80.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called rsxx.
+
 endif # BLK_DEV

drivers/block/Makefile

@@ -41,4 +41,6 @@ obj-$(CONFIG_BLK_DEV_DRBD)     += drbd/
 obj-$(CONFIG_BLK_DEV_RBD)     += rbd.o
 obj-$(CONFIG_BLK_DEV_PCIESSD_MTIP32XX)	+= mtip32xx/
 
+obj-$(CONFIG_BLK_DEV_RSXX) += rsxx/
+
 swim_mod-y	:= swim.o swim_asm.o

drivers/block/rsxx/Makefile

@@ -0,0 +1,2 @@
+obj-$(CONFIG_BLK_DEV_RSXX) += rsxx.o
+rsxx-y := config.o core.o cregs.o dev.o dma.o

drivers/block/rsxx/config.c

@@ -0,0 +1,213 @@
+/*
+* Filename: config.c
+*
+*
+* Authors: Joshua Morris <[email protected]>
+*	Philip Kelleher <[email protected]>
+*
+* (C) Copyright 2013 IBM Corporation
+*
+* 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.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software Foundation,
+* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include <linux/types.h>
+#include <linux/crc32.h>
+#include <linux/swab.h>
+
+#include "rsxx_priv.h"
+#include "rsxx_cfg.h"
+
+static void initialize_config(void *config)
+{
+	struct rsxx_card_cfg *cfg = (struct rsxx_card_cfg *) config;
+
+	cfg->hdr.version = RSXX_CFG_VERSION;
+
+	cfg->data.block_size        = RSXX_HW_BLK_SIZE;
+	cfg->data.stripe_size       = RSXX_HW_BLK_SIZE;
+	cfg->data.vendor_id         = RSXX_VENDOR_ID_TMS_IBM;
+	cfg->data.cache_order       = (-1);
+	cfg->data.intr_coal.mode    = RSXX_INTR_COAL_DISABLED;
+	cfg->data.intr_coal.count   = 0;
+	cfg->data.intr_coal.latency = 0;
+}
+
+static u32 config_data_crc32(struct rsxx_card_cfg *cfg)
+{
+	/*
+	 * Return the compliment of the CRC to ensure compatibility
+	 * (i.e. this is how early rsxx drivers did it.)
+	 */
+
+	return ~crc32(~0, &cfg->data, sizeof(cfg->data));
+}
+
+
+/*----------------- Config Byte Swap Functions -------------------*/
+static void config_hdr_be_to_cpu(struct card_cfg_hdr *hdr)
+{
+	hdr->version = be32_to_cpu((__force __be32) hdr->version);
+	hdr->crc     = be32_to_cpu((__force __be32) hdr->crc);
+}
+
+static void config_hdr_cpu_to_be(struct card_cfg_hdr *hdr)
+{
+	hdr->version = (__force u32) cpu_to_be32(hdr->version);
+	hdr->crc     = (__force u32) cpu_to_be32(hdr->crc);
+}
+
+static void config_data_swab(struct rsxx_card_cfg *cfg)
+{
+	u32 *data = (u32 *) &cfg->data;
+	int i;
+
+	for (i = 0; i < (sizeof(cfg->data) / 4); i++)
+		data[i] = swab32(data[i]);
+}
+
+static void config_data_le_to_cpu(struct rsxx_card_cfg *cfg)
+{
+	u32 *data = (u32 *) &cfg->data;
+	int i;
+
+	for (i = 0; i < (sizeof(cfg->data) / 4); i++)
+		data[i] = le32_to_cpu((__force __le32) data[i]);
+}
+
+static void config_data_cpu_to_le(struct rsxx_card_cfg *cfg)
+{
+	u32 *data = (u32 *) &cfg->data;
+	int i;
+
+	for (i = 0; i < (sizeof(cfg->data) / 4); i++)
+		data[i] = (__force u32) cpu_to_le32(data[i]);
+}
+
+
+/*----------------- Config Operations ------------------*/
+int rsxx_save_config(struct rsxx_cardinfo *card)
+{
+	struct rsxx_card_cfg cfg;
+	int st;
+
+	memcpy(&cfg, &card->config, sizeof(cfg));
+
+	if (unlikely(cfg.hdr.version != RSXX_CFG_VERSION)) {
+		dev_err(CARD_TO_DEV(card),
+			"Cannot save config with invalid version %d\n",
+			cfg.hdr.version);
+		return -EINVAL;
+	}
+
+	/* Convert data to little endian for the CRC calculation. */
+	config_data_cpu_to_le(&cfg);
+
+	cfg.hdr.crc = config_data_crc32(&cfg);
+
+	/*
+	 * Swap the data from little endian to big endian so it can be
+	 * stored.
+	 */
+	config_data_swab(&cfg);
+	config_hdr_cpu_to_be(&cfg.hdr);
+
+	st = rsxx_creg_write(card, CREG_ADD_CONFIG, sizeof(cfg), &cfg, 1);
+	if (st)
+		return st;
+
+	return 0;
+}
+
+int rsxx_load_config(struct rsxx_cardinfo *card)
+{
+	int st;
+	u32 crc;
+
+	st = rsxx_creg_read(card, CREG_ADD_CONFIG, sizeof(card->config),
+				&card->config, 1);
+	if (st) {
+		dev_err(CARD_TO_DEV(card),
+			"Failed reading card config.\n");
+		return st;
+	}
+
+	config_hdr_be_to_cpu(&card->config.hdr);
+
+	if (card->config.hdr.version == RSXX_CFG_VERSION) {
+		/*
+		 * We calculate the CRC with the data in little endian, because
+		 * early drivers did not take big endian CPUs into account.
+		 * The data is always stored in big endian, so we need to byte
+		 * swap it before calculating the CRC.
+		 */
+
+		config_data_swab(&card->config);
+
+		/* Check the CRC */
+		crc = config_data_crc32(&card->config);
+		if (crc != card->config.hdr.crc) {
+			dev_err(CARD_TO_DEV(card),
+				"Config corruption detected!\n");
+			dev_info(CARD_TO_DEV(card),
+				"CRC (sb x%08x is x%08x)\n",
+				card->config.hdr.crc, crc);
+			return -EIO;
+		}
+
+		/* Convert the data to CPU byteorder */
+		config_data_le_to_cpu(&card->config);
+
+	} else if (card->config.hdr.version != 0) {
+		dev_err(CARD_TO_DEV(card),
+			"Invalid config version %d.\n",
+			card->config.hdr.version);
+		/*
+		 * Config version changes require special handling from the
+		 * user
+		 */
+		return -EINVAL;
+	} else {
+		dev_info(CARD_TO_DEV(card),
+			"Initializing card configuration.\n");
+		initialize_config(card);
+		st = rsxx_save_config(card);
+		if (st)
+			return st;
+	}
+
+	card->config_valid = 1;
+
+	dev_dbg(CARD_TO_DEV(card), "version:     x%08x\n",
+		card->config.hdr.version);
+	dev_dbg(CARD_TO_DEV(card), "crc:         x%08x\n",
+		card->config.hdr.crc);
+	dev_dbg(CARD_TO_DEV(card), "block_size:  x%08x\n",
+		card->config.data.block_size);
+	dev_dbg(CARD_TO_DEV(card), "stripe_size: x%08x\n",
+		card->config.data.stripe_size);
+	dev_dbg(CARD_TO_DEV(card), "vendor_id:   x%08x\n",
+		card->config.data.vendor_id);
+	dev_dbg(CARD_TO_DEV(card), "cache_order: x%08x\n",
+		card->config.data.cache_order);
+	dev_dbg(CARD_TO_DEV(card), "mode:        x%08x\n",
+		card->config.data.intr_coal.mode);
+	dev_dbg(CARD_TO_DEV(card), "count:       x%08x\n",
+		card->config.data.intr_coal.count);
+	dev_dbg(CARD_TO_DEV(card), "latency:     x%08x\n",
+		 card->config.data.intr_coal.latency);
+
+	return 0;
+}
+