init gnumach copy

1 files changed, 1038 insertions, 0 deletions

diff --git a/linux/dev/drivers/block/ahci.c b/linux/dev/drivers/block/ahci.c
new file mode 100644
index 0000000..751c7ca
--- /dev/null
+++ b/linux/dev/drivers/block/ahci.c
@@ -0,0 +1,1038 @@
+/*
+ *  Copyright (C) 2013 Free Software Foundation
+ *
+ * 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 the program ; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <ahci.h>
+#include <kern/assert.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/fs.h>
+#include <linux/bios32.h>
+#include <linux/major.h>
+#include <linux/hdreg.h>
+#include <linux/genhd.h>
+#include <asm/io.h>
+
+#define MAJOR_NR SCSI_DISK_MAJOR
+#include <linux/blk.h>
+
+/* Standard AHCI BAR for mmio */
+#define AHCI_PCI_BAR 5
+
+/* minor: 2 bits for device number, 6 bits for partition number. */
+
+#define MAX_PORTS 8
+#define PARTN_BITS 5
+#define PARTN_MASK ((1<<PARTN_BITS)-1)
+
+/* We need to use one DMA scatter element per physical page.
+ * ll_rw_block creates at most 8 buffer heads */
+/* See MAX_BUF */
+#define PRDTL_SIZE 8
+
+#define WAIT_MAX (1*HZ) /* Wait at most 1s for requests completion */
+
+/* AHCI standard structures */
+
+struct ahci_prdt {
+	u32 dba;			/* Data base address */
+	u32 dbau;			/* upper 32bit */
+	u32 rsv0;			/* Reserved */
+
+	u32 dbc;			/* Byte count bits 0-21,
+					 * bit31 interrupt on completion. */
+};
+
+struct ahci_cmd_tbl {
+	u8 cfis[64];
+	u8 acmd[16];
+	u8 rsv[48];
+
+	struct ahci_prdt prdtl[PRDTL_SIZE];
+};
+
+struct ahci_command {
+	u32 opts;			/* Command options */
+
+	u32 prdbc;			/* Physical Region Descriptor byte count */
+
+	u32 ctba;			/* Command Table Descriptor Base Address */
+	u32 ctbau;			/* upper 32bit */
+
+	u32 rsv1[4];			/* Reserved */
+};
+
+struct ahci_fis_dma {
+	u8 fis_type;
+	u8 flags;
+	u8 rsved[2];
+	u64 id;
+	u32 rsvd;
+	u32 offset;
+	u32 count;
+	u32 resvd;
+};
+
+struct ahci_fis_pio {
+	u8 fis_type;
+	u8 flags;
+	u8 status;
+	u8 error;
+
+	u8 lba0;
+	u8 lba1;
+	u8 lba2;
+	u8 device;
+
+	u8 lba3;
+	u8 lba4;
+	u8 lba5;
+	u8 rsv2;
+
+	u8 countl;
+	u8 counth;
+	u8 rsv3;
+	u8 e_status;
+
+	u16 tc;	/* Transfer Count */
+	u8 rsv4[2];
+};
+
+struct ahci_fis_d2h {
+	u8 fis_type;
+	u8 flags;
+	u8 status;
+	u8 error;
+
+	u8 lba0;
+	u8 lba1;
+	u8 lba2;
+	u8 device;
+
+	u8 lba3;
+	u8 lba4;
+	u8 lba5;
+	u8 rsv2;
+
+	u8 countl;
+	u8 counth;
+	u8 rsv3[2];
+
+	u8 rsv4[4];
+};
+
+struct ahci_fis_dev {
+	u8 rsvd[8];
+};
+
+struct ahci_fis_h2d {
+	u8 fis_type;
+	u8 flags;
+	u8 command;
+	u8 featurel;
+
+	u8 lba0;
+	u8 lba1;
+	u8 lba2;
+	u8 device;
+
+	u8 lba3;
+	u8 lba4;
+	u8 lba5;
+	u8 featureh;
+
+	u8 countl;
+	u8 counth;
+	u8 icc;
+	u8 control;
+
+	u8 rsv1[4];
+};
+
+struct ahci_fis_data {
+	u8 fis_type;
+	u8 flags;
+	u8 rsv1[2];
+	u32 data1[];
+};
+
+struct ahci_fis {
+	struct ahci_fis_dma dma_fis;
+	u8 pad0[4];
+
+	struct ahci_fis_pio pio_fis;
+	u8 pad1[12];
+
+	struct ahci_fis_d2h d2h_fis;
+	u8 pad2[4];
+
+	struct ahci_fis_dev dev_fis;
+
+	u8 ufis[64];
+
+	u8 rsv[0x100 - 0xa0];
+};
+
+struct ahci_port {
+	u32 clb;			/* Command List Base address */
+	u32 clbu;			/* upper 32bit */
+	u32 fb;				/* FIS Base */
+	u32 fbu;			/* upper 32bit */
+	u32 is;				/* Interrupt Status */
+	u32 ie;				/* Interrupt Enable */
+	u32 cmd;			/* Command and Status */
+	u32 rsv0;			/* Reserved */
+	u32 tfd;			/* Task File Data */
+	u32 sig;			/* Signature */
+	u32 ssts;			/* SATA Status */
+	u32 sctl;			/* SATA Control */
+	u32 serr;			/* SATA Error */
+	u32 sact;			/* SATA Active */
+	u32 ci;				/* Command Issue */
+	u32 sntf;			/* SATA Notification */
+	u32 fbs;			/* FIS-based switch control */
+	u8 rsv1[0x70 - 0x44];		/* Reserved */
+	u8 vendor[0x80 - 0x70];		/* Vendor-specific */
+};
+
+struct ahci_host {
+	u32 cap;			/* Host capabilities */
+	u32 ghc;			/* Global Host Control */
+	u32 is;				/* Interrupt Status */
+	u32 pi;				/* Port Implemented */
+	u32 v;				/* Version */
+	u32 ccc_ctl;			/* Command Completion Coalescing control */
+	u32 ccc_pts;			/* Command Completion Coalescing ports */
+	u32 em_loc;			/* Enclosure Management location */
+	u32 em_ctrl;			/* Enclosure Management control */
+	u32 cap2;			/* Host capabilities extended */
+	u32 bohc;			/* BIOS/OS Handoff Control and status */
+	u8 rsv[0xa0 - 0x2c];		/* Reserved */
+	u8 vendor[0x100 - 0xa0];	/* Vendor-specific */
+	struct ahci_port ports[];	/* Up to 32 ports */
+};
+
+/* Our own data */
+
+static struct port {
+	/* memory-mapped regions */
+	const volatile struct ahci_host *ahci_host;
+	const volatile struct ahci_port *ahci_port;
+
+	/* host-memory buffers */
+	struct ahci_command *command;
+	struct ahci_fis *fis;
+	struct ahci_cmd_tbl *prdtl;
+
+	struct hd_driveid id;
+	unsigned is_cd;
+	unsigned long long capacity;	/* Nr of sectors */
+	u32 status;			/* interrupt status */
+	unsigned cls;			/* Command list maximum size.
+					   We currently only use 1. */
+	struct wait_queue *q;		/* IRQ wait queue */
+	struct hd_struct *part;		/* drive partition table */
+	unsigned lba48;			/* Whether LBA48 is supported */
+	unsigned identify;		/* Whether we are just identifying
+					   at boot */
+	struct gendisk *gd;
+} ports[MAX_PORTS];
+
+
+/* do_request() gets called by the block layer to push a request to the disk.
+   We just push one, and when an interrupt tells it's over, we call do_request()
+   ourself again to push the next request, etc. */
+
+/* Request completed, either successfully or with an error */
+static void ahci_end_request(int uptodate)
+{
+	struct request *rq = CURRENT;
+	struct buffer_head *bh;
+
+	rq->errors = 0;
+	if (!uptodate) {
+		if (!rq->quiet)
+			printk("end_request: I/O error, dev %s, sector %lu\n",
+					kdevname(rq->rq_dev), rq->sector);
+	}
+
+	for (bh = rq->bh; bh; )
+	{
+		struct buffer_head *next = bh->b_reqnext;
+		bh->b_reqnext = NULL;
+		mark_buffer_uptodate (bh, uptodate);
+		unlock_buffer (bh);
+		bh = next;
+	}
+
+	CURRENT = rq->next;
+	if (rq->sem != NULL)
+		up(rq->sem);
+	rq->rq_status = RQ_INACTIVE;
+	wake_up(&wait_for_request);
+}
+
+/* Push the request to the controler port */
+static int ahci_do_port_request(struct port *port, unsigned long long sector, struct request *rq)
+{
+	struct ahci_command *command = port->command;
+	struct ahci_cmd_tbl *prdtl = port->prdtl;
+	struct ahci_fis_h2d *fis_h2d;
+	unsigned slot = 0;
+	struct buffer_head *bh;
+	unsigned i;
+
+	rq->rq_status = RQ_SCSI_BUSY;
+
+	/* Shouldn't ever happen: the block glue is limited at 8 blocks */
+	assert(rq->nr_sectors < 0x10000);
+
+	fis_h2d = (void*) &prdtl[slot].cfis;
+	fis_h2d->fis_type = FIS_TYPE_REG_H2D;
+	fis_h2d->flags = 128;
+	if (port->lba48) {
+		if (sector >= 1ULL << 48) {
+			printk("sector %llu beyond LBA48\n", sector);
+			return -EOVERFLOW;
+		}
+		if (rq->cmd == READ)
+			fis_h2d->command = WIN_READDMA_EXT;
+		else
+			fis_h2d->command = WIN_WRITEDMA_EXT;
+	} else {
+		if (sector >= 1ULL << 28) {
+			printk("sector %llu beyond LBA28\n", sector);
+			return -EOVERFLOW;
+		}
+		if (rq->cmd == READ)
+			fis_h2d->command = WIN_READDMA;
+		else
+			fis_h2d->command = WIN_WRITEDMA;
+	}
+
+	fis_h2d->device = 1<<6;	/* LBA */
+
+	fis_h2d->lba0 = sector;
+	fis_h2d->lba1 = sector >> 8;
+	fis_h2d->lba2 = sector >> 16;
+
+	fis_h2d->lba3 = sector >> 24;
+	fis_h2d->lba4 = sector >> 32;
+	fis_h2d->lba5 = sector >> 40;
+
+	fis_h2d->countl = rq->nr_sectors;
+	fis_h2d->counth = rq->nr_sectors >> 8;
+
+	command[slot].opts = sizeof(*fis_h2d) / sizeof(u32);
+
+	if (rq->cmd == WRITE)
+		command[slot].opts |= AHCI_CMD_WRITE;
+
+	for (i = 0, bh = rq->bh; bh; i++, bh = bh->b_reqnext)
+	{
+		assert(i < PRDTL_SIZE);
+		assert((((unsigned long) bh->b_data) & ~PAGE_MASK) ==
+			(((unsigned long) bh->b_data + bh->b_size - 1) & ~PAGE_MASK));
+		prdtl[slot].prdtl[i].dbau = 0;
+		prdtl[slot].prdtl[i].dba = vmtophys(bh->b_data);
+		prdtl[slot].prdtl[i].dbc = bh->b_size - 1;
+	}
+
+	command[slot].opts |= i << 16;
+
+	/* Make sure main memory buffers are up to date */
+	mb();
+
+	/* Issue command */
+	writel(1 << slot, &port->ahci_port->ci);
+
+	/* TODO: IRQ timeout handler */
+	return 0;
+}
+
+/* Called by block core to push a request */
+/* TODO: ideally, would have one request queue per port */
+/* TODO: ideally, would use tags to process several requests at a time */
+static void ahci_do_request()	/* invoked with cli() */
+{
+	struct request *rq;
+	unsigned minor, unit;
+	unsigned long long block, blockend;
+	struct port *port;
+
+	rq = CURRENT;
+	if (!rq)
+		return;
+
+	if (rq->rq_status != RQ_ACTIVE)
+		/* Current one is already ongoing, let the interrupt handler
+		 * push the new one when the current one is finished. */
+		return;
+
+	if (MAJOR(rq->rq_dev) != MAJOR_NR) {
+		printk("bad ahci major %u\n", MAJOR(rq->rq_dev));
+		goto kill_rq;
+	}
+
+	minor = MINOR(rq->rq_dev);
+	unit = minor >> PARTN_BITS;
+	if (unit >= MAX_PORTS) {
+		printk("bad ahci unit %u\n", unit);
+		goto kill_rq;
+	}
+
+	port = &ports[unit];
+
+	/* Compute start sector */
+	block = rq->sector;
+	block += port->part[minor & PARTN_MASK].start_sect;
+
+	/* And check end */
+	blockend = block + rq->nr_sectors;
+	if (blockend < block) {
+		if (!rq->quiet)
+			printk("bad blockend %lu vs %lu\n", (unsigned long) blockend, (unsigned long) block);
+		goto kill_rq;
+	}
+	if (blockend > port->capacity) {
+		if (!rq->quiet)
+		{
+			printk("offset for %u was %lu\n", minor, port->part[minor & PARTN_MASK].start_sect);
+			printk("bad access: block %lu, count= %lu\n", (unsigned long) blockend, (unsigned long) port->capacity);
+		}
+		goto kill_rq;
+	}
+
+	/* Push this to the port */
+	if (ahci_do_port_request(port, block, rq))
+		goto kill_rq;
+	return;
+
+kill_rq:
+	ahci_end_request(0);
+}
+
+/* The given port got an interrupt, terminate the current request if any */
+static void ahci_port_interrupt(struct port *port, u32 status)
+{
+	unsigned slot = 0;
+
+	if (readl(&port->ahci_port->ci) & (1 << slot)) {
+		/* Command still pending */
+		return;
+	}
+
+	if (port->identify) {
+		port->status = status;
+		wake_up(&port->q);
+		return;
+	}
+
+	if (!CURRENT || CURRENT->rq_status != RQ_SCSI_BUSY) {
+		/* No request currently running */
+		return;
+	}
+
+	if (status & (PORT_IRQ_TF_ERR | PORT_IRQ_HBUS_ERR | PORT_IRQ_HBUS_DATA_ERR | PORT_IRQ_IF_ERR | PORT_IRQ_IF_NONFATAL)) {
+		printk("ahci error %x %x\n", status, readl(&port->ahci_port->tfd));
+		ahci_end_request(0);
+		return;
+	}
+
+	ahci_end_request(1);
+}
+
+/* Start of IRQ handler. Iterate over all ports for this host */
+static void ahci_interrupt (int irq, void *host, struct pt_regs *regs)
+{
+	struct port *port;
+	struct ahci_host *ahci_host = host;
+	u32 irq_mask;
+	u32 status;
+
+	irq_mask = readl(&ahci_host->is);
+
+	if (!irq_mask)
+		return;
+
+	for (port = &ports[0]; port < &ports[MAX_PORTS]; port++) {
+		if (port->ahci_host == ahci_host && (irq_mask & (1 << (port->ahci_port - ahci_host->ports)))) {
+			status = readl(&port->ahci_port->is);
+			/* Clear interrupt before possibly triggering others */
+			writel(status, &port->ahci_port->is);
+			ahci_port_interrupt (port, status);
+		}
+	}
+
+	if (CURRENT)
+		/* Still some requests, queue another one */
+		ahci_do_request();
+
+	/* Clear host after clearing ports */
+	writel(irq_mask, &ahci_host->is);
+
+	/* unlock */
+}
+
+static int ahci_ioctl (struct inode *inode, struct file *file,
+			unsigned int cmd, unsigned long arg)
+{
+	int major, unit;
+
+	if (!inode || !inode->i_rdev)
+		return -EINVAL;
+
+	major = MAJOR(inode->i_rdev);
+	if (major != MAJOR_NR)
+		return -ENOTTY;
+
+	unit = DEVICE_NR(inode->i_rdev);
+	if (unit >= MAX_PORTS)
+		return -EINVAL;
+
+	switch (cmd) {
+		case BLKRRPART:
+			if (!suser()) return -EACCES;
+			if (!ports[unit].gd)
+				return -EINVAL;
+			resetup_one_dev(ports[unit].gd, unit);
+			return 0;
+		default:
+			return -EPERM;
+	}
+}
+
+static int ahci_open (struct inode *inode, struct file *file)
+{
+	int target;
+
+	if (MAJOR(inode->i_rdev) != MAJOR_NR)
+		return -ENXIO;
+
+	target = MINOR(inode->i_rdev) >> PARTN_BITS;
+	if (target >= MAX_PORTS)
+		return -ENXIO;
+
+	if (!ports[target].ahci_port)
+		return -ENXIO;
+
+	return 0;
+}
+
+static void ahci_release (struct inode *inode, struct file *file)
+{
+}
+
+static int ahci_fsync (struct inode *inode, struct file *file)
+{
+	printk("fsync\n");
+	return -ENOSYS;
+}
+
+static struct file_operations ahci_fops = {
+	.lseek = NULL,
+	.read = block_read,
+	.write = block_write,
+	.readdir = NULL,
+	.select = NULL,
+	.ioctl = ahci_ioctl,
+	.mmap = NULL,
+	.open = ahci_open,
+	.release = ahci_release,
+	.fsync = ahci_fsync,
+	.fasync = NULL,
+	.check_media_change = NULL,
+	.revalidate = NULL,
+};
+
+/* Disk timed out while processing identify, interrupt ahci_probe_port */
+static void identify_timeout(unsigned long data)
+{
+	struct port *port = (void*) data;
+
+	wake_up(&port->q);
+}
+
+static struct timer_list identify_timer = { .function = identify_timeout };
+
+static int ahci_identify(const volatile struct ahci_host *ahci_host, const volatile struct ahci_port *ahci_port, struct port *port, unsigned cmd)
+{
+	struct hd_driveid id;
+	struct ahci_fis_h2d *fis_h2d;
+	struct ahci_command *command = port->command;
+	struct ahci_cmd_tbl *prdtl = port->prdtl;
+	unsigned long flags;
+	unsigned slot;
+	unsigned long first_part;
+	unsigned long long timeout;
+	int ret = 0;
+
+	/* Identify device */
+	/* TODO: make this a request */
+	slot = 0;
+
+	fis_h2d = (void*) &prdtl[slot].cfis;
+	fis_h2d->fis_type = FIS_TYPE_REG_H2D;
+	fis_h2d->flags = 128;
+	fis_h2d->command = cmd;
+	fis_h2d->device = 0;
+
+	/* Fetch the 512 identify data */
+	memset(&id, 0, sizeof(id));
+
+	command[slot].opts = sizeof(*fis_h2d) / sizeof(u32);
+
+	first_part = PAGE_ALIGN((unsigned long) &id) - (unsigned long) &id;
+
+	if (first_part && first_part < sizeof(id)) {
+		/* split over two pages */
+
+		command[slot].opts |= (2 << 16);
+
+		prdtl[slot].prdtl[0].dbau = 0;
+		prdtl[slot].prdtl[0].dba = vmtophys((void*) &id);
+		prdtl[slot].prdtl[0].dbc = first_part - 1;
+		prdtl[slot].prdtl[1].dbau = 0;
+		prdtl[slot].prdtl[1].dba = vmtophys((void*) &id + first_part);
+		prdtl[slot].prdtl[1].dbc = sizeof(id) - first_part - 1;
+	}
+	else
+	{
+		command[slot].opts |= (1 << 16);
+
+		prdtl[slot].prdtl[0].dbau = 0;
+		prdtl[slot].prdtl[0].dba = vmtophys((void*) &id);
+		prdtl[slot].prdtl[0].dbc = sizeof(id) - 1;
+	}
+
+	timeout = jiffies + WAIT_MAX;
+	while (readl(&ahci_port->tfd) & (BUSY_STAT | DRQ_STAT))
+		if (jiffies > timeout) {
+			printk("sd%u: timeout waiting for ready\n", port-ports);
+			port->ahci_host = NULL;
+			port->ahci_port = NULL;
+			return 3;
+		}
+
+	save_flags(flags);
+	cli();
+
+	port->identify = 1;
+	port->status = 0;
+
+	/* Issue command */
+	mb();
+	writel(1 << slot, &ahci_port->ci);
+
+	timeout = jiffies + WAIT_MAX;
+	identify_timer.expires = timeout;
+	identify_timer.data = (unsigned long) port;
+	add_timer(&identify_timer);
+	while (!port->status) {
+		if (jiffies >= timeout) {
+                       printk("sd%u: timeout waiting for identify\n", port-ports);
+			port->ahci_host = NULL;
+			port->ahci_port = NULL;
+			del_timer(&identify_timer);
+			restore_flags(flags);
+			return 3;
+		}
+		sleep_on(&port->q);
+	}
+	del_timer(&identify_timer);
+	restore_flags(flags);
+
+	if ((port->status & PORT_IRQ_TF_ERR) || readl(&ahci_port->is) & PORT_IRQ_TF_ERR)
+	{
+		/* Identify error */
+		port->capacity = 0;
+		port->lba48 = 0;
+		ret = 2;
+	} else {
+		memcpy(&port->id, &id, sizeof(id));
+		port->is_cd = 0;
+
+		ide_fixstring(id.model,     sizeof(id.model),     1);
+		ide_fixstring(id.fw_rev,    sizeof(id.fw_rev),    1);
+		ide_fixstring(id.serial_no, sizeof(id.serial_no), 1);
+		if (cmd == WIN_PIDENTIFY)
+		{
+			unsigned char type = (id.config >> 8) & 0x1f;
+
+			printk("sd%u: %s, ATAPI ", port - ports, id.model);
+			if (type == 5)
+			{
+				printk("unsupported CDROM drive\n");
+				port->is_cd = 1;
+				port->lba48 = 0;
+				port->capacity = 0;
+			}
+			else
+			{
+				printk("unsupported type %d\n", type);
+				port->lba48 = 0;
+				port->capacity = 0;
+				return 2;
+			}
+			return 0;
+		}
+
+		if (id.command_set_2 & (1U<<10))
+		{
+			port->lba48 = 1;
+			port->capacity = id.lba_capacity_2;
+			if (port->capacity >= (1ULL << 32))
+			{
+				port->capacity = (1ULL << 32) - 1;
+				printk("Warning: truncating disk size to 2TiB\n");
+			}
+		}
+		else
+		{
+			port->lba48 = 0;
+			port->capacity = id.lba_capacity;
+			if (port->capacity > (1ULL << 24))
+			{
+				port->capacity = (1ULL << 24);
+				printk("Warning: truncating disk size to 128GiB\n");
+			}
+		}
+		if (port->capacity/2048 >= 10240)
+			printk("sd%u: %s, %uGB w/%dkB Cache\n", (unsigned) (port - ports), id.model, (unsigned) (port->capacity/(2048*1024)), id.buf_size/2);
+		else
+			printk("sd%u: %s, %uMB w/%dkB Cache\n", (unsigned) (port - ports), id.model, (unsigned) (port->capacity/2048), id.buf_size/2);
+	}
+	port->identify = 0;
+
+	return ret;
+}
+
+/* Probe one AHCI port */
+static void ahci_probe_port(const volatile struct ahci_host *ahci_host, const volatile struct ahci_port *ahci_port)
+{
+	struct port *port;
+	void *mem;
+	unsigned cls = ((readl(&ahci_host->cap) >> 8) & 0x1f) + 1;
+	struct ahci_command *command;
+	struct ahci_fis *fis;
+	struct ahci_cmd_tbl *prdtl;
+	vm_size_t size =
+		  cls * sizeof(*command)
+		+ sizeof(*fis)
+		+ cls * sizeof(*prdtl);
+	unsigned i;
+	unsigned long long timeout;
+
+	for (i = 0; i < MAX_PORTS; i++) {
+		if (!ports[i].ahci_port)
+			break;
+	}
+	if (i == MAX_PORTS)
+		return;
+	port = &ports[i];
+
+	/* Has to be 1K-aligned */
+	mem = vmalloc (size);
+	if (!mem)
+		return;
+	assert (!(((unsigned long) mem) & (1024-1)));
+	memset (mem, 0, size);
+
+	port->ahci_host = ahci_host;
+	port->ahci_port = ahci_port;
+	port->cls = cls;
+
+	port->command = command = mem;
+	port->fis = fis = (void*) command + cls * sizeof(*command);
+	port->prdtl = prdtl = (void*) fis + sizeof(*fis);
+
+	/* Stop commands */
+	writel(readl(&ahci_port->cmd) & ~PORT_CMD_START, &ahci_port->cmd);
+	timeout = jiffies + WAIT_MAX;
+	while (readl(&ahci_port->cmd) & PORT_CMD_LIST_ON)
+		if (jiffies > timeout) {
+			printk("sd%u: timeout waiting for list completion\n", (unsigned) (port-ports));
+			port->ahci_host = NULL;
+			port->ahci_port = NULL;
+			return;
+		}
+
+	writel(readl(&ahci_port->cmd) & ~PORT_CMD_FIS_RX, &ahci_port->cmd);
+	timeout = jiffies + WAIT_MAX;
+	while (readl(&ahci_port->cmd) & PORT_CMD_FIS_ON)
+		if (jiffies > timeout) {
+			printk("sd%u: timeout waiting for FIS completion\n", (unsigned) (port-ports));
+			port->ahci_host = NULL;
+			port->ahci_port = NULL;
+			return;
+		}
+
+	/* We don't support 64bit */
+	/* Point controller to our buffers */
+	writel(0, &ahci_port->clbu);
+	writel(vmtophys((void*) command), &ahci_port->clb);
+	writel(0, &ahci_port->fbu);
+	writel(vmtophys((void*) fis), &ahci_port->fb);
+
+	/* Clear any previous interrupts */
+	writel(readl(&ahci_port->is), &ahci_port->is);
+	writel(1 << (ahci_port - ahci_host->ports), &ahci_host->is);
+
+	/* And activate them */
+	writel(DEF_PORT_IRQ, &ahci_port->ie);
+	writel(readl(&ahci_host->ghc) | HOST_IRQ_EN, &ahci_host->ghc);
+
+	for (i = 0; i < cls; i++)
+	{
+		command[i].ctbau = 0;
+		command[i].ctba = vmtophys((void*) &prdtl[i]);
+	}
+
+	/* Start commands */
+	timeout = jiffies + WAIT_MAX;
+	while (readl(&ahci_port->cmd) & PORT_CMD_LIST_ON)
+		if (jiffies > timeout) {
+			printk("sd%u: timeout waiting for list completion\n", (unsigned) (port-ports));
+			port->ahci_host = NULL;
+			port->ahci_port = NULL;
+			return;
+		}
+
+	writel(readl(&ahci_port->cmd) | PORT_CMD_FIS_RX | PORT_CMD_START, &ahci_port->cmd);
+
+       /* if PxCMD.ATAPI is set, try ATAPI identify; otherwise try AHCI, then ATAPI */
+       if (readl(&ahci_port->cmd) & PORT_CMD_ATAPI ||
+              ahci_identify(ahci_host, ahci_port, port, WIN_IDENTIFY) >= 2)
+                ahci_identify(ahci_host, ahci_port, port, WIN_PIDENTIFY);
+}
+
+/* Probe one AHCI PCI device */
+static void ahci_probe_dev(unsigned char bus, unsigned char device)
+{
+	unsigned char hdrtype;
+	unsigned char dev, fun;
+	const volatile struct ahci_host *ahci_host;
+	const volatile struct ahci_port *ahci_port;
+	unsigned nports, n, i;
+	unsigned port_map;
+	unsigned bar;
+	unsigned char irq;
+
+	dev = PCI_SLOT(device);
+	fun = PCI_FUNC(device);
+
+	/* Get configuration */
+	if (pcibios_read_config_byte(bus, device, PCI_HEADER_TYPE, &hdrtype) != PCIBIOS_SUCCESSFUL) {
+		printk("ahci: %02x:%02x.%x: Can not read configuration", bus, dev, fun);
+		return;
+	}
+	/* Ignore multifunction bit */
+	hdrtype &= ~0x80;
+
+	if (hdrtype != 0) {
+		printk("ahci: %02x:%02x.%x: Unknown hdrtype %d\n", bus, dev, fun, hdrtype);
+		return;
+	}
+
+	if (pcibios_read_config_dword(bus, device, PCI_BASE_ADDRESS_5, &bar) != PCIBIOS_SUCCESSFUL) {
+		printk("ahci: %02x:%02x.%x: Can not read BAR 5", bus, dev, fun);
+		return;
+	}
+	if (bar & PCI_BASE_ADDRESS_SPACE_IO) {
+		printk("ahci: %02x:%02x.%x: BAR 5 is I/O?!", bus, dev, fun);
+		return;
+	}
+	bar &= PCI_BASE_ADDRESS_MEM_MASK;
+
+	if (pcibios_read_config_byte(bus, device, PCI_INTERRUPT_LINE, &irq) != PCIBIOS_SUCCESSFUL) {
+		printk("ahci: %02x:%02x.%x: Can not read IRQ", bus, dev, fun);
+		return;
+	}
+
+	printk("AHCI SATA %02x:%02x.%x BAR 0x%x IRQ %u\n", bus, dev, fun, bar, irq);
+
+	/* Map mmio */
+	ahci_host = vremap(bar, 0x2000);
+
+	/* Request IRQ */
+	if (request_irq(irq, &ahci_interrupt, SA_SHIRQ, "ahci", (void*) ahci_host)) {
+		printk("ahci: %02x:%02x.%x: Can not get irq %u\n", bus, dev, fun, irq);
+		return;
+	}
+
+#ifdef CONFIG_BLK_DEV_IDE
+	/* OK, we will handle it. Disable probing on legacy IDE ports it may have.  */
+	for (i = 0; i < 6; i++)
+	{
+		unsigned mybar;
+		if (pcibios_read_config_dword(bus, device, PCI_BASE_ADDRESS_0 + i*4, &mybar) == PCIBIOS_SUCCESSFUL) {
+			if (!(bar & PCI_BASE_ADDRESS_SPACE_IO))
+				/* Memory, don't care */
+				continue;
+			/* printk("ahci: %02x:%02x.%x: BAR %d is %x\n", bus, dev, fun, i, mybar); */
+			ide_disable_base(bar & PCI_BASE_ADDRESS_IO_MASK);
+		}
+	}
+#endif
+
+	nports = (readl(&ahci_host->cap) & 0x1f) + 1;
+	port_map = readl(&ahci_host->pi);
+
+	for (n = 0, i = 0; i < AHCI_MAX_PORTS; i++)
+		if (port_map & (1U << i))
+			n++;
+
+	if (nports != n) {
+		printk("ahci: %02x:%02x.%x: Odd number of ports %u, assuming %u is correct\n", bus, dev, fun, n, nports);
+		port_map = 0;
+	}
+	if (!port_map) {
+		port_map = (1U << nports) - 1;
+	}
+
+	for (i = 0; i < AHCI_MAX_PORTS; i++) {
+		u32 ssts;
+               u8 det, ipm;
+
+		if (!(port_map & (1U << i)))
+			continue;
+
+		ahci_port = &ahci_host->ports[i];
+
+		ssts = readl(&ahci_port->ssts);
+               det = ssts & 0xf;
+               switch (det)
+		{
+			case 0x0:
+				/* Device not present */
+				continue;
+			case 0x1:
+				printk("ahci: %02x:%02x.%x: Port %u communication not established. TODO: power on device\n", bus, dev, fun, i);
+				continue;
+			case 0x3:
+				/* Present and communication established */
+				break;
+			case 0x4:
+				printk("ahci: %02x:%02x.%x: Port %u phy offline?!\n", bus, dev, fun, i);
+				continue;
+			default:
+                               printk("ahci: %02x:%02x.%x: Unknown port %u DET %x\n", bus, dev, fun, i, det);
+				continue;
+		}
+
+		ipm = (ssts >> 8) & 0xf;
+		switch (ipm)
+		{
+			case 0x0:
+				/* Device not present */
+				continue;
+			case 0x1:
+				/* Active */
+				break;
+			case 0x2:
+				printk("ahci: %02x:%02x.%x: Port %u in Partial power management. TODO: power on device\n", bus, dev, fun, i);
+				continue;
+			case 0x6:
+				printk("ahci: %02x:%02x.%x: Port %u in Slumber power management. TODO: power on device\n", bus, dev, fun, i);
+				continue;
+			default:
+				printk("ahci: %02x:%02x.%x: Unknown port %u IPM %x\n", bus, dev, fun, i, ipm);
+				continue;
+		}
+
+		/* OK! Probe this port */
+		ahci_probe_port(ahci_host, ahci_port);
+	}
+}
+
+/* genhd callback to set size of disks */
+static void ahci_geninit(struct gendisk *gd)
+{
+	unsigned unit;
+	struct port *port;
+
+	for (unit = 0; unit < gd->nr_real; unit++) {
+		port = &ports[unit];
+		port->part[0].nr_sects = port->capacity;
+		if (!port->part[0].nr_sects)
+			port->part[0].nr_sects = -1;
+	}
+}
+
+/* Probe all AHCI PCI devices */
+void ahci_probe_pci(void)
+{
+	unsigned char bus, device;
+	unsigned short index;
+	int ret;
+	unsigned nports, unit, nminors;
+	struct port *port;
+	struct gendisk *gd, **gdp;
+	int *bs;
+
+	for (index = 0;
+		(ret = pcibios_find_class(PCI_CLASS_STORAGE_SATA_AHCI, index, &bus, &device)) == PCIBIOS_SUCCESSFUL;
+		index++)
+	{
+		/* Note: this prevents from also having a SCSI controler.
+		 * It shouldn't harm too much until we have proper hardware
+		 * enumeration.
+		 */
+		if (register_blkdev(MAJOR_NR, "sd", &ahci_fops) < 0)
+			printk("could not register ahci\n");
+		ahci_probe_dev(bus, device);
+	}
+
+	for (nports = 0, port = &ports[0]; port < &ports[MAX_PORTS]; port++)
+		if (port->ahci_port)
+			nports++;
+
+	nminors = nports * (1<<PARTN_BITS);
+
+	gd              = kmalloc(sizeof(*gd), GFP_KERNEL);
+	gd->sizes       = kmalloc(nminors * sizeof(*gd->sizes), GFP_KERNEL);
+	gd->part        = kmalloc(nminors * sizeof(*gd->part), GFP_KERNEL);
+	bs              = kmalloc(nminors * sizeof(*bs), GFP_KERNEL);
+
+	blksize_size[MAJOR_NR] = bs;
+	for (unit = 0; unit < nminors; unit++)
+		/* We prefer to transfer whole pages */
+		*bs++ = PAGE_SIZE;
+
+	memset(gd->part, 0, nminors * sizeof(*gd->part));
+
+	for (unit = 0; unit < nports; unit++) {
+		ports[unit].gd = gd;
+		ports[unit].part = &gd->part[unit << PARTN_BITS];
+	}
+
+	gd->major       = MAJOR_NR;
+	gd->major_name  = "sd";
+	gd->minor_shift = PARTN_BITS;
+	gd->max_p       = 1<<PARTN_BITS;
+	gd->max_nr      = nports;
+	gd->nr_real     = nports;
+	gd->init        = ahci_geninit;
+	gd->next        = NULL;
+
+	for (gdp = &gendisk_head; *gdp; gdp = &((*gdp)->next))
+		;
+	*gdp = gd;
+
+	blk_dev[MAJOR_NR].request_fn = ahci_do_request;
+}