Added (untested) support for ATA devices. This code should be generic

enough to support both real IDE chipsets and AoE.

2 files changed, 362 insertions, 0 deletions

diff --git a/src/drivers/block/ata.c b/src/drivers/block/ata.c
new file mode 100644
index 000000000..0e4c77923
--- /dev/null
+++ b/src/drivers/block/ata.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stddef.h>
+#include <string.h>
+#include <byteswap.h>
+#include <gpxe/blockdev.h>
+#include <gpxe/ata.h>
+
+/** @file
+ *
+ * ATA block device
+ *
+ */
+
+static inline __attribute__ (( always_inline )) struct ata_device *
+block_to_ata ( struct block_device *blockdev ) {
+	return container_of ( blockdev, struct ata_device, blockdev );
+}
+
+/**
+ * Issue ATA command
+ *
+ * @v ata		ATA device
+ * @v command		ATA command
+ * @ret rc		Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+ata_command ( struct ata_device *ata, struct ata_command *command ) {
+	DBG ( "ATA cmd %02x dev %02x fl %02x LBA %llx count %04x\n",
+	      command.cb.cmd_stat, command.cb.device, command.cb.flags,
+	      ( unsigned long long ) command.cb.lba.native,
+	      command.cb.count.native );
+
+	return ata->command ( ata, command );	
+}
+
+/**
+ * Read block from / write block to ATA device
+ *
+ * @v write		Write flag (ATA_FL_WRITE or 0)
+ * @v blockdev		Block device
+ * @v block		LBA block number
+ * @v count		Block count
+ * @v buffer		Data buffer
+ * @ret rc		Return status code
+ */
+static __attribute__ (( regparm ( 1 ) )) int
+ata_rw ( int write, struct block_device *blockdev, uint64_t block,
+	 unsigned long count, userptr_t buffer ) {
+	struct ata_device *ata = block_to_ata ( blockdev );
+	struct ata_command command;
+	int lba48 = ( ata->flags & ATA_FL_LBA48 );
+
+	memset ( &command, 0, sizeof ( command ) );
+	command.cb.lba.native = block;
+	command.cb.count.native = count;
+	command.cb.device = ( ata->flags | ATA_DEV_OBSOLETE | ATA_DEV_LBA );
+	command.cb.flags = ( ata->flags | write );
+	command.cb.cmd_stat = ( write ? ATA_CMD_WRITE : ATA_CMD_READ );
+	if ( lba48 ) {
+		command.cb.cmd_stat |= ATA_CMD_EXT;
+	} else {
+		command.cb.device |= command.cb.lba.bytes.low_prev;
+	}
+	command.data = buffer;
+	command.data_len = ( count * blockdev->blksize );
+	return ata_command ( ata, &command );
+}
+
+/**
+ * Read block from ATA device
+ *
+ * @v blockdev		Block device
+ * @v block		LBA block number
+ * @v count		Block count
+ * @v buffer		Data buffer
+ * @ret rc		Return status code
+ */
+static int ata_read ( struct block_device *blockdev, uint64_t block,
+		      unsigned long count, userptr_t buffer ) {
+	/* Pass through to ata_rw().  Since ata_rw is regparm(1), this
+	 * is extremely efficient; just a mov and a jmp.
+	 */
+	return ata_rw ( 0, blockdev, block, count, buffer );
+}
+
+/**
+ * Write block to ATA device
+ *
+ * @v blockdev		Block device
+ * @v block		LBA block number
+ * @v count		Block count
+ * @v buffer		Data buffer
+ * @ret rc		Return status code
+ */
+static int ata_write ( struct block_device *blockdev, uint64_t block,
+		       unsigned long count, userptr_t buffer ) {
+	/* Pass through to ata_rw().  Since ata_rw is regparm(1), this
+	 * is extremely efficient; just a mov and a jmp.
+	 */
+	return ata_rw ( ATA_FL_WRITE, blockdev, block, count, buffer );
+}
+
+/**
+ * Identify ATA device
+ *
+ * @v blockdev		Block device
+ * @ret rc		Return status code
+ */
+static int ata_identify ( struct block_device *blockdev ) {
+	struct ata_device *ata = block_to_ata ( blockdev );
+	struct ata_command command;
+	struct ata_identity identity;
+	int rc;
+
+	/* Issue IDENTIFY */
+	memset ( &command, 0, sizeof ( command ) );
+	command.cb.device = ( ata->flags | ATA_DEV_OBSOLETE | ATA_DEV_LBA );
+	command.cb.cmd_stat = ATA_CMD_IDENTIFY;
+	command.data = virt_to_user ( &identity );
+	command.data_len = sizeof ( identity );
+	if ( ( rc = ata_command ( ata, &command ) ) != 0 )
+		return rc;
+
+	/* Fill in block device parameters */
+	blockdev->blksize = ATA_SECTOR_SIZE;
+	if ( identity.supports_lba48 & cpu_to_le16 ( ATA_SUPPORTS_LBA48 ) ) {
+		ata->flags |= ATA_FL_LBA48;
+		blockdev->blocks = le64_to_cpu ( identity.lba48_sectors );
+	} else {
+		blockdev->blocks = le32_to_cpu ( identity.lba_sectors );
+	}
+	return 0;
+}
+
+/**
+ * Initialise ATA device
+ *
+ * @v ata		ATA device
+ * @ret rc		Return status code
+ *
+ * Initialises an ATA device.  The ata_device::command field and the
+ * @c ATA_FL_SLAVE portion of the ata_device::flags field must already
+ * be filled in.  This function will configure ata_device::blockdev,
+ * including issuing an IDENTIFY DEVICE call to determine the block
+ * size and total device size.
+ */
+int init_atadev ( struct ata_device *ata ) {
+	/** Fill in read and write methods, and get device capacity */
+	ata->blockdev.read = ata_read;
+	ata->blockdev.write = ata_write;
+	return ata_identify ( &ata->blockdev );
+}
diff --git a/src/include/gpxe/ata.h b/src/include/gpxe/ata.h
new file mode 100644
index 000000000..3cc01cf8c
--- /dev/null
+++ b/src/include/gpxe/ata.h
@@ -0,0 +1,193 @@
+#ifndef _GPXE_ATA_H
+#define _GPXE_ATA_H
+
+#include <stdint.h>
+#include <gpxe/blockdev.h>
+#include <gpxe/uaccess.h>
+
+/** @file
+ *
+ * ATA devices
+ *
+ */
+
+/**
+ * An ATA Logical Block Address
+ *
+ * ATA controllers have three byte-wide registers for specifying the
+ * block address: LBA Low, LBA Mid and LBA High.  This allows for a
+ * 24-bit address.  Some devices support the "48-bit address feature
+ * set" (LBA48), in which case each of these byte-wide registers is
+ * actually a two-entry FIFO, and the "previous" byte pushed into the
+ * FIFO is used as the corresponding high-order byte.  So, to set up
+ * the 48-bit address 0x12345678abcd, you would issue
+ *
+ *     0x56 -> LBA Low register
+ *     0xcd -> LBA Low register
+ *     0x34 -> LBA Mid register
+ *     0xab -> LBA Mid register
+ *     0x12 -> LBA High register
+ *     0x78 -> LBA High register
+ *
+ * This structure encapsulates this information by providing a single
+ * 64-bit integer in native byte order, unioned with bytes named so
+ * that the sequence becomes
+ *
+ *     low_prev  -> LBA Low register
+ *     low_cur   -> LBA Low register
+ *     mid_prev  -> LBA Mid register
+ *     mid_cur   -> LBA Mid register
+ *     high_prev -> LBA High register
+ *     high_cur  -> LBA High register
+ *
+ * Just to complicate matters further, in non-LBA48 mode it is
+ * possible to have a 28-bit address, in which case bits 27:24 must be
+ * written into the low four bits of the Device register.
+ */
+union ata_lba {
+	/** LBA as a 64-bit integer in native-endian order */
+	uint64_t native;
+	/** ATA registers */
+	struct {
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+		uint8_t low_cur;
+		uint8_t mid_cur;
+		uint8_t high_cur;
+		uint8_t low_prev;
+		uint8_t mid_prev;
+		uint8_t high_prev;
+		uint8_t pad[2];
+#elif __BYTE_ORDER == __BIG_ENDIAN
+		uint8_t pad[2];
+		uint8_t high_prev;
+		uint8_t mid_prev;
+		uint8_t low_prev;
+		uint8_t high_cur;
+		uint8_t mid_cur;
+		uint8_t low_cur;
+#else
+#error "I need a byte order"
+#endif
+	} bytes;
+};
+
+/** An ATA 2-byte FIFO register */
+union ata_fifo {
+	/** Value in native-endian order */
+	uint16_t native;
+	/** ATA registers */
+	struct {
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+		uint8_t cur;
+		uint8_t prev;
+#elif __BYTE_ORDER == __BIG_ENDIAN
+		uint8_t prev;
+		uint8_t cur;
+#else
+#error "I need a byte order"
+#endif
+	} bytes;
+};
+
+/** ATA command block */
+struct ata_cb {
+	/** Logical block address */
+	union ata_lba lba;
+	/** Sector count */
+	union ata_fifo count;
+	/** Error/feature register */
+	union ata_fifo err_feat;
+	/** Device register */
+	uint8_t device;
+	/** Command/status register */
+	uint8_t cmd_stat;
+	/** Flags
+	 *
+	 * This field does not correspond to any ATA register.
+	 */
+	uint8_t flags;
+};
+
+/** LBA48 extended addressing */
+#define ATA_FL_LBA48 0x40
+
+/** Device 1 ("slave") */
+#define ATA_FL_SLAVE 0x10
+
+/** Write command */
+#define ATA_FL_WRITE 0x01
+
+/** Obsolete bits in the ATA device register */
+#define ATA_DEV_OBSOLETE 0xa0
+
+/** LBA flag in the ATA device register */
+#define ATA_DEV_LBA 0x40
+
+/** "Read sectors" command */
+#define ATA_CMD_READ 0x20
+
+/** "Write sectors" command */
+#define ATA_CMD_WRITE 0x30
+
+/** "Identify" command */
+#define ATA_CMD_IDENTIFY 0xec
+
+/** "Extended (LBA48)" command modifier
+ *
+ * This doesn't apply to all ATA commands, but it does for @c
+ * ATA_CMD_READ and @c ATA_CMD_WRITE.
+ */
+#define ATA_CMD_EXT 0x04
+
+/** An ATA command */
+struct ata_command {
+	/** ATA command block */
+	struct ata_cb cb;
+	/** Data buffer */
+	userptr_t data;
+	/** Data buffer length */
+	size_t data_len;
+};
+
+/**
+ * Structure returned by ATA IDENTIFY command
+ *
+ * This is a huge structure with many fields that we don't care about,
+ * so we implement only a few fields.
+ */
+struct ata_identity {
+	uint16_t ignore_a[60]; /* words 0-59 */
+	uint32_t lba_sectors; /* words 60-61 */
+	uint16_t ignore_b[21]; /* words 62-82 */
+	uint16_t supports_lba48; /* word 83 */
+	uint16_t ignore_c[16]; /* words 84-99 */
+	uint64_t lba48_sectors; /* words 100-103 */
+	uint16_t ignore_d[152]; /* words 104-255 */
+};
+
+/** Supports LBA48 flag */
+#define ATA_SUPPORTS_LBA48 ( 1 << 10 )
+
+/** ATA sector size */
+#define ATA_SECTOR_SIZE 512
+
+/** An ATA device */
+struct ata_device {
+	/** Block device interface */
+	struct block_device blockdev;
+	/** Flags */
+	int flags;
+	/**
+	 * Issue ATA command
+	 *
+	 * @v ata		ATA device
+	 * @v command		ATA command
+	 * @ret rc		Return status code
+	 */
+	int ( * command ) ( struct ata_device *ata,
+			    struct ata_command *command );
+};
+
+extern int init_atadev ( struct ata_device *ata );
+
+#endif /* _GPXE_ATA_H */