[PATCH] HP iLO driver

[David Altobelli <david.altobelli@hp.com>]

A driver for the HP iLO/iLO2 management processor, which allows userspace
programs to query the management processor.  Programs can open a channel
to the device (/dev/hpilo_ccbN), and use this to send/receive queries.  
The O_EXCL open flag is used to indicate that a particular channel cannot
be shared between processes.  This driver will replace various packages
HP has shipped, including hprsm and hp-ilo.

Please CC me on any replies, thanks for your time.

Signed-off-by: David Altobelli <david.altobelli@hp.com>
---
 Kconfig  |   13 +
 Makefile |    1 
 hpilo.c  |  696 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 hpilo.h  |  218 +++++++++++++++++++
 4 files changed, 928 insertions(+)
diff -urpN linux-2.6.25.orig/drivers/char/hpilo.c linux-2.6.25/drivers/char/hpilo.c
--- linux-2.6.25.orig/drivers/char/hpilo.c	1969-12-31 18:00:00.000000000 -0600
+++ linux-2.6.25/drivers/char/hpilo.c	2008-06-12 13:05:14.000000000 -0500
@@ -0,0 +1,696 @@
+/*
+ * Driver for HP iLO/iLO2 management processor.
+ *
+ * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
+ *	David Altobelli <david.altobelli@hp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/pci.h>
+#include <linux/ioport.h>
+#include <linux/device.h>
+#include <linux/file.h>
+#include <linux/cdev.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include "hpilo.h"
+
+static struct class *ilo_class;
+static unsigned int ilo_major;
+static char ilo_hwdev[MAX_ILO_DEV];
+
+/*
+ * FIFO queues, shared with hardware.
+ *
+ * If a queue has empty slots, an entry is added to the queue tail,
+ * and that entry is marked as occupied.
+ * Entries can be dequeued from the head of the list, when the device
+ * has marked the entry as consumed.
+ *
+ * Returns true on successful queue/dequeue, false on failure.
+ */
+static int fifo_enqueue(struct ilo_hwinfo *hw, char *fifobar, int entry)
+{
+	struct fifo *Q = FIFOBARTOHANDLE(fifobar);
+	int ret = 0;
+
+	spin_lock(&hw->fifo_lock);
+	if (!(Q->fifobar[(Q->tail + 1) & Q->imask] & ENTRY_MASK_O)) {
+		Q->fifobar[Q->tail & Q->imask] |=
+			((entry & ENTRY_MASK_NOSTATE) | Q->merge);
+		Q->tail += 1;
+		ret = 1;
+	}
+	spin_unlock(&hw->fifo_lock);
+
+	return ret;
+}
+
+static int fifo_dequeue(struct ilo_hwinfo *hw, char *fifobar, int *entry)
+{
+	struct fifo *Q = FIFOBARTOHANDLE(fifobar);
+	int ret = 0;
+	u64 c;
+
+	spin_lock(&hw->fifo_lock);
+	c = Q->fifobar[Q->head & Q->imask];
+	if (c & ENTRY_MASK_C) {
+		if (entry)
+			*entry = c & ENTRY_MASK_NOSTATE;
+
+		Q->fifobar[Q->head & Q->imask] = ((c | ENTRY_MASK) + 1);
+		Q->head += 1;
+		ret = 1;
+	}
+	spin_unlock(&hw->fifo_lock);
+
+	return ret;
+}
+
+static int ilo_pkt_enqueue(struct ilo_hwinfo *hw, struct ccb *ccb,
+			   int dir, int id, int len)
+{
+	char *fifobar;
+	int entry;
+
+	if (dir == SENDQ)
+		fifobar = ccb->ccb_u1.send_fifobar;
+	else
+		fifobar = ccb->ccb_u3.recv_fifobar;
+
+	entry = id << ENTRY_BITPOS_DESCRIPTOR |
+		QWORDS(len) << ENTRY_BITPOS_QWORDS;
+
+	return fifo_enqueue(hw, fifobar, entry);
+}
+
+static int ilo_pkt_dequeue(struct ilo_hwinfo *hw, struct ccb *ccb,
+			   int dir, int *id, int *len, void **pkt)
+{
+	char *fifobar, *desc;
+	int entry = 0, pkt_id = 0;
+	int ret;
+
+	if (dir == SENDQ) {
+		fifobar = ccb->ccb_u1.send_fifobar;
+		desc = ccb->ccb_u2.send_desc;
+	} else {
+		fifobar = ccb->ccb_u3.recv_fifobar;
+		desc = ccb->ccb_u4.recv_desc;
+	}
+
+	ret = fifo_dequeue(hw, fifobar, &entry);
+	if (ret) {
+		pkt_id = GETDESC(entry);
+		if (id)
+			*id = pkt_id;
+		if (len)
+			*len = GETQWORDS(entry) << 3;
+		if (pkt)
+			*pkt = (void *)(desc + DESC_MEM_SZ(pkt_id));
+	}
+
+	return ret;
+}
+
+static void ctrl_setup(struct ccb *ccb, int nr_desc, int l2desc_sz)
+{
+	/* for simplicity, use the same parameters for send and recv ctrls */
+	CTRL_SET(ccb->send_ctrl, l2desc_sz, nr_desc-1, nr_desc-1, 0, 1);
+	CTRL_SET(ccb->recv_ctrl, l2desc_sz, nr_desc-1, nr_desc-1, 0, 1);
+}
+
+static void fifo_setup(void *base_addr, int nr_entry)
+{
+	struct fifo *Q = base_addr;
+	int i;
+
+	/* set up an empty fifo */
+	Q->head = 0;
+	Q->tail = 0;
+	Q->reset = 0;
+	Q->nrents = nr_entry;
+	Q->imask = nr_entry - 1;
+	Q->merge = ENTRY_MASK_O;
+
+	for (i = 0; i < nr_entry; i++)
+		Q->fifobar[i] = 0;
+}
+
+static void ilo_ccb_close(struct pci_dev *pdev, struct ccb_data *data)
+{
+	struct ccb *driver_ccb;
+	struct ccb __iomem *device_ccb;
+	int retries;
+
+	driver_ccb = &data->driver_ccb;
+	device_ccb = data->mapped_ccb;
+
+	/* complicated dance to tell the hw we are stopping */
+	DOORBELL_CLR(driver_ccb);
+	iowrite32(ioread32(&device_ccb->send_ctrl) & ~(1 << CTRL_BITPOS_G),
+		  &device_ccb->send_ctrl);
+	iowrite32(ioread32(&device_ccb->recv_ctrl) & ~(1 << CTRL_BITPOS_G),
+		  &device_ccb->recv_ctrl);
+
+	/* give iLO some time to process stop request */
+	for (retries = 1000; retries > 0; retries--) {
+		DOORBELL_SET(driver_ccb);
+		udelay(1);
+		if (!(ioread32(&device_ccb->send_ctrl) & (1 << CTRL_BITPOS_A))
+		    &&
+		    !(ioread32(&device_ccb->recv_ctrl) & (1 << CTRL_BITPOS_A)))
+			break;
+	}
+	if (retries == 0)
+		dev_err(&pdev->dev, "Closing, but controller still active\n");
+
+	/* clear the hw ccb */
+	memset_io(device_ccb, 0, sizeof(struct ccb));
+
+	/* free resources used to back send/recv queues */
+	pci_free_consistent(pdev, data->dma_size, data->dma_va, data->dma_pa);
+}
+
+static int ilo_ccb_open(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
+{
+	char *dma_va, *dma_pa;
+	int pkt_id, pkt_sz, i, error;
+	struct ccb *driver_ccb, *ilo_ccb;
+	struct pci_dev *pdev;
+
+	driver_ccb = &data->driver_ccb;
+	ilo_ccb = &data->ilo_ccb;
+	pdev = hw->ilo_dev;
+
+	data->dma_size = 2 * FIFO_SZ(NR_QENTRY) +
+			 2 * DESC_MEM_SZ(NR_QENTRY) +
+			 ILO_START_ALIGN + ILO_CACHE_SZ;
+
+	error = -ENOMEM;
+	data->dma_va = pci_alloc_consistent(pdev, data->dma_size,
+					    &data->dma_pa);
+	if (!data->dma_va)
+		goto out;
+
+	dma_va = (char *)data->dma_va;
+	dma_pa = (char *)data->dma_pa;
+
+	memset(dma_va, 0, data->dma_size);
+
+	dma_va = (char *)roundup((unsigned long)dma_va, ILO_START_ALIGN);
+	dma_pa = (char *)roundup((unsigned long)dma_pa, ILO_START_ALIGN);
+
+	/*
+	 * Create two ccb's, one with virt addrs, one with phys addrs.
+	 * Copy the phys addr ccb to device shared mem.
+	 */
+	ctrl_setup(driver_ccb, NR_QENTRY, L2_QENTRY_SZ);
+	ctrl_setup(ilo_ccb, NR_QENTRY, L2_QENTRY_SZ);
+
+	fifo_setup(dma_va, NR_QENTRY);
+	driver_ccb->ccb_u1.send_fifobar = (dma_va + FIFOHANDLESIZE);
+	ilo_ccb->ccb_u1.send_fifobar = (dma_pa + FIFOHANDLESIZE);
+	dma_va += FIFO_SZ(NR_QENTRY);
+	dma_pa += FIFO_SZ(NR_QENTRY);
+
+	dma_va = (char *)roundup((unsigned long)dma_va, ILO_CACHE_SZ);
+	dma_pa = (char *)roundup((unsigned long)dma_pa, ILO_CACHE_SZ);
+
+	fifo_setup(dma_va, NR_QENTRY);
+	driver_ccb->ccb_u3.recv_fifobar = (dma_va + FIFOHANDLESIZE);
+	ilo_ccb->ccb_u3.recv_fifobar = (dma_pa + FIFOHANDLESIZE);
+	dma_va += FIFO_SZ(NR_QENTRY);
+	dma_pa += FIFO_SZ(NR_QENTRY);
+
+	driver_ccb->ccb_u2.send_desc = dma_va;
+	ilo_ccb->ccb_u2.send_desc = dma_pa;
+	dma_pa += DESC_MEM_SZ(NR_QENTRY);
+	dma_va += DESC_MEM_SZ(NR_QENTRY);
+
+	driver_ccb->ccb_u4.recv_desc = dma_va;
+	ilo_ccb->ccb_u4.recv_desc = dma_pa;
+
+	driver_ccb->channel = slot;
+	ilo_ccb->channel = slot;
+
+	driver_ccb->ccb_u5.db_base = hw->db_vaddr + (slot << L2_DB_SIZE);
+	ilo_ccb->ccb_u5.db_base = NULL; /* hw ccb's doorbell is not used */
+
+	/* copy the ccb with physical addrs to device memory */
+	data->mapped_ccb = (struct ccb __iomem *)
+				(hw->ram_vaddr + (slot * ILOHW_CCB_SZ));
+	memcpy_toio(data->mapped_ccb, ilo_ccb, sizeof(struct ccb));
+
+	/* put packets on the send and receive queues */
+	pkt_sz = 0;
+	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++) {
+		ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, pkt_sz);
+		DOORBELL_SET(driver_ccb);
+	}
+
+	pkt_sz = DESC_MEM_SZ(1);
+	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++)
+		ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, pkt_sz);
+
+	DOORBELL_CLR(driver_ccb);
+
+	/* make sure iLO is really handling requests */
+	for (i = 1000; i > 0; i--) {
+		if (ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, NULL, NULL))
+			break;
+		udelay(1);
+	}
+
+	if (i) {
+		ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, 0);
+		DOORBELL_SET(driver_ccb);
+	} else {
+		dev_err(&pdev->dev, "Open could not dequeue a packet\n");
+		error = -EBUSY;
+		goto free;
+	}
+
+	return 0;
+free:
+	pci_free_consistent(pdev, data->dma_size, data->dma_va, data->dma_pa);
+out:
+	return error;
+}
+
+static void ilo_locked_reset(struct ilo_hwinfo *hw)
+{
+	int slot;
+
+	/*
+	 * Mapped memory is zeroed on ilo reset, so set a per ccb flag
+	 * to indicate that this ccb needs to be closed and reopened.
+	 */
+	for (slot = 0; slot < MAX_CCB; slot++) {
+		if (!hw->ccb_alloc[slot])
+			continue;
+		SET_CHANNEL_RESET(&hw->ccb_alloc[slot]->driver_ccb);
+	}
+
+	CLEAR_DEVICE(hw);
+}
+
+static void ilo_reset(struct ilo_hwinfo *hw)
+{
+	spin_lock(&hw->alloc_lock);
+
+	/* reset might have been handled after lock was taken */
+	if (IS_DEVICE_RESET(hw))
+		ilo_locked_reset(hw);
+
+	spin_unlock(&hw->alloc_lock);
+}
+
+static ssize_t ilo_read(struct file *fp, char __user *buf,
+			size_t len, loff_t *off)
+{
+	int err, found, cnt, pkt_id, pkt_len;
+	struct ccb_data *data;
+	struct ccb *driver_ccb;
+	struct ilo_hwinfo *hw;
+	void *pkt;
+
+	data = fp->private_data;
+	driver_ccb = &data->driver_ccb;
+	hw = data->ilo_hw;
+
+	if (IS_DEVICE_RESET(hw) || IS_CHANNEL_RESET(driver_ccb)) {
+		/*
+		 * If the device has been reset, applications
+		 * need to close and reopen all ccbs.
+		 */
+		ilo_reset(hw);
+		return -ENODEV;
+	}
+
+	/*
+	 * This function is to be called when data is expected
+	 * in the channel, and will return an error if no packet is found
+	 * during the loop below.  The sleep/retry logic is to allow
+	 * applications to call read() immediately post write(),
+	 * and give iLO some time to process the sent packet.
+	 */
+	cnt = 20;
+	do {
+		/* look for a received packet */
+		found = ilo_pkt_dequeue(hw, driver_ccb, RECVQ, &pkt_id,
+					&pkt_len, &pkt);
+		if (found)
+			break;
+		cnt--;
+		msleep(100);
+	} while (!found && cnt);
+
+	if (!found)
+		return -EAGAIN;
+
+	/* only copy the length of the received packet */
+	if (pkt_len < len)
+		len = pkt_len;
+
+	err = copy_to_user(buf, pkt, len);
+
+	/* return the received packet to the queue */
+	ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, DESC_MEM_SZ(1));
+
+	return (err ? -EFAULT : len);
+}
+
+static ssize_t ilo_write(struct file *fp, const char __user *buf,
+			 size_t len, loff_t *off)
+{
+	int err, pkt_id, pkt_len;
+	struct ccb_data *data;
+	struct ccb *driver_ccb;
+	struct ilo_hwinfo *hw;
+	void *pkt;
+
+	data = fp->private_data;
+	driver_ccb = &data->driver_ccb;
+	hw = data->ilo_hw;
+
+	if (IS_DEVICE_RESET(hw) || IS_CHANNEL_RESET(driver_ccb)) {
+		/*
+		 * If the device has been reset, applications
+		 * need to close and reopen all ccbs.
+		 */
+		ilo_reset(hw);
+		return -ENODEV;
+	}
+
+	/* get a packet to send the user command */
+	if (!ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, &pkt_len, &pkt))
+		return -EBUSY;
+
+	/* limit the length to the length of the packet */
+	if (pkt_len < len)
+		len = pkt_len;
+
+	/* on failure, set the len to 0 to return empty packet to the device */
+	err = copy_from_user(pkt, buf, len);
+	if (err)
+		len = 0;
+
+	/* send the packet */
+	ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, len);
+	DOORBELL_SET(driver_ccb);
+
+	return (err ? -EFAULT : len);
+}
+
+static int ilo_close(struct inode *ip, struct file *fp)
+{
+	int slot;
+	struct ccb_data *data;
+	struct ilo_hwinfo *hw;
+
+	slot = iminor(ip) % MAX_CCB;
+	hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);
+
+	spin_lock(&hw->alloc_lock);
+
+	if (IS_DEVICE_RESET(hw))
+		ilo_locked_reset(hw);
+
+	if (hw->ccb_alloc[slot]->ccb_cnt == 1) {
+
+		data = fp->private_data;
+
+		ilo_ccb_close(hw->ilo_dev, data);
+
+		kfree(data);
+		hw->ccb_alloc[slot] = NULL;
+	} else
+		hw->ccb_alloc[slot]->ccb_cnt--;
+
+	spin_unlock(&hw->alloc_lock);
+
+	return 0;
+}
+
+static int ilo_open(struct inode *ip, struct file *fp)
+{
+	int slot, error;
+	struct ccb_data *data;
+	struct ilo_hwinfo *hw;
+
+	slot = iminor(ip) % MAX_CCB;
+	hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);
+
+	spin_lock(&hw->alloc_lock);
+
+	if (IS_DEVICE_RESET(hw))
+		ilo_locked_reset(hw);
+
+	/* each fd private_data holds sw/hw view of ccb */
+	if (hw->ccb_alloc[slot] == NULL) {
+		/* new ccb allocation */
+		error = -ENOMEM;
+		data = kzalloc(sizeof(struct ccb_data), GFP_KERNEL);
+		if (!data)
+			goto out;
+
+		/* create a channel control block for this minor */
+		error = ilo_ccb_open(hw, data, slot);
+		if (error)
+			goto free;
+
+		hw->ccb_alloc[slot] = data;
+		hw->ccb_alloc[slot]->ccb_cnt = 1;
+		hw->ccb_alloc[slot]->ccb_excl = fp->f_flags & O_EXCL;
+		hw->ccb_alloc[slot]->ilo_hw = hw;
+	} else if (fp->f_flags & O_EXCL || hw->ccb_alloc[slot]->ccb_excl) {
+		/* either this open or a previous open wants exclusive access */
+		error = -EBUSY;
+		goto out;
+	} else
+		hw->ccb_alloc[slot]->ccb_cnt++;
+
+	spin_unlock(&hw->alloc_lock);
+
+	fp->private_data = hw->ccb_alloc[slot];
+
+	return 0;
+free:
+	kfree(data);
+out:
+	spin_unlock(&hw->alloc_lock);
+	return error;
+}
+
+static const struct file_operations ilo_fops = {
+	THIS_MODULE,
+	.read		= ilo_read,
+	.write		= ilo_write,
+	.open 		= ilo_open,
+	.release 	= ilo_close,
+};
+
+static void ilo_unmap_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
+{
+	pci_iounmap(pdev, hw->db_vaddr);
+	pci_iounmap(pdev, hw->ram_vaddr);
+	pci_iounmap(pdev, hw->mmio_vaddr);
+}
+
+static int __devinit ilo_map_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
+{
+	int error = -ENOMEM;
+
+	/* map the memory mapped i/o registers */
+	hw->mmio_vaddr = pci_iomap(pdev, 1, 0);
+	if (hw->mmio_vaddr == NULL) {
+		dev_err(&pdev->dev, "Error mapping mmio\n");
+		goto out;
+	}
+
+	/* map the adapter shared memory region */
+	hw->ram_vaddr = pci_iomap(pdev, 2, MAX_CCB * ILOHW_CCB_SZ);
+	if (hw->ram_vaddr == NULL) {
+		dev_err(&pdev->dev, "Error mapping shared mem\n");
+		goto mmio_free;
+	}
+
+	/* map the doorbell aperture */
+	hw->db_vaddr = pci_iomap(pdev, 3, MAX_CCB * ONE_DB_SIZE);
+	if (hw->db_vaddr == NULL) {
+		dev_err(&pdev->dev, "Error mapping doorbell\n");
+		goto ram_free;
+	}
+
+	return 0;
+ram_free:
+	pci_iounmap(pdev, hw->ram_vaddr);
+mmio_free:
+	pci_iounmap(pdev, hw->mmio_vaddr);
+out:
+	return error;
+}
+
+static void ilo_remove(struct pci_dev *pdev)
+{
+	int i, minor;
+	struct ilo_hwinfo *ilo_hw = pci_get_drvdata(pdev);
+
+	CLEAR_DEVICE(ilo_hw);
+
+	minor = MINOR(ilo_hw->cdev.dev);
+	for (i = minor; i < minor + MAX_CCB; i++)
+		device_destroy(ilo_class, MKDEV(ilo_major, i));
+
+	cdev_del(&ilo_hw->cdev);
+	ilo_unmap_device(pdev, ilo_hw);
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	kfree(ilo_hw);
+	ilo_hwdev[(minor / MAX_CCB)] = 0;
+}
+
+static int __devinit ilo_probe(struct pci_dev *pdev,
+			       const struct pci_device_id *ent)
+{
+	int devnum, minor, start, end, error;
+	struct ilo_hwinfo *ilo_hw;
+
+	/* find a free range for device files */
+	for (devnum = 0; devnum < MAX_ILO_DEV; devnum++) {
+		if (ilo_hwdev[devnum] == 0) {
+			ilo_hwdev[devnum] = 1;
+			break;
+		}
+	}
+
+	if (devnum == MAX_ILO_DEV) {
+		dev_err(&pdev->dev, "Error finding free device\n");
+		return -ENODEV;
+	}
+
+	/* track global allocations for this device */
+	error = -ENOMEM;
+	ilo_hw = kzalloc(sizeof(struct ilo_hwinfo), GFP_KERNEL);
+	if (!ilo_hw)
+		goto out;
+
+	ilo_hw->ilo_dev = pdev;
+	spin_lock_init(&ilo_hw->alloc_lock);
+	spin_lock_init(&ilo_hw->fifo_lock);
+
+	error = pci_enable_device(pdev);
+	if (error)
+		goto free;
+
+	pci_set_master(pdev);
+
+	error = pci_request_regions(pdev, ILO_NAME);
+	if (error)
+		goto disable;
+
+	error = ilo_map_device(pdev, ilo_hw);
+	if (error)
+		goto free_regions;
+
+	pci_set_drvdata(pdev, ilo_hw);
+	CLEAR_DEVICE(ilo_hw);
+
+	cdev_init(&ilo_hw->cdev, &ilo_fops);
+	ilo_hw->cdev.owner = THIS_MODULE;
+	start = devnum * MAX_CCB;
+	error = cdev_add(&ilo_hw->cdev, MKDEV(ilo_major, start), MAX_CCB);
+	if (error) {
+		dev_err(&pdev->dev, "Could not add cdev\n");
+		goto unmap;
+	}
+
+	end = start + MAX_CCB;
+	for (minor = start ; minor < end; minor++) {
+		if (IS_ERR(device_create(ilo_class, &pdev->dev,
+					 MKDEV(ilo_major, minor),
+					 "hpilo_ccb%d", minor)))
+			dev_err(&pdev->dev, "Could not create files\n");
+	}
+
+	return 0;
+unmap:
+	ilo_unmap_device(pdev, ilo_hw);
+free_regions:
+	pci_release_regions(pdev);
+disable:
+	pci_disable_device(pdev);
+free:
+	kfree(ilo_hw);
+out:
+	ilo_hwdev[devnum] = 0;
+	return error;
+}
+
+static struct pci_device_id ilo_devices[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB204) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, ilo_devices);
+
+static struct pci_driver ilo_driver = {
+	.name 	  = ILO_NAME,
+	.id_table = ilo_devices,
+	.probe 	  = ilo_probe,
+	.remove   = __devexit_p(ilo_remove),
+};
+
+static int __init ilo_init(void)
+{
+	int error;
+	dev_t dev;
+
+	ilo_class = class_create(THIS_MODULE, "iLO");
+	if (IS_ERR(ilo_class)) {
+		error = PTR_ERR(ilo_class);
+		goto out;
+	}
+
+	error = alloc_chrdev_region(&dev, 0, MAX_OPEN, ILO_NAME);
+	if (error)
+		goto class_destroy;
+
+	ilo_major = MAJOR(dev);
+
+	error =	pci_register_driver(&ilo_driver);
+	if (error)
+		goto chr_remove;
+
+	return 0;
+chr_remove:
+	unregister_chrdev_region(dev, MAX_OPEN);
+class_destroy:
+	class_destroy(ilo_class);
+out:
+	return error;
+}
+
+static void __exit ilo_exit(void)
+{
+	pci_unregister_driver(&ilo_driver);
+	unregister_chrdev_region(MKDEV(ilo_major, 0), MAX_OPEN);
+	class_destroy(ilo_class);
+}
+
+MODULE_VERSION("0.01");
+MODULE_ALIAS("hpilo");
+MODULE_DESCRIPTION(ILO_NAME);
+MODULE_AUTHOR("David Altobelli <david.altobelli@hp.com>");
+MODULE_LICENSE("GPL v2");
+
+module_init(ilo_init);
+module_exit(ilo_exit);
diff -urpN linux-2.6.25.orig/drivers/char/hpilo.h linux-2.6.25/drivers/char/hpilo.h
--- linux-2.6.25.orig/drivers/char/hpilo.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-2.6.25/drivers/char/hpilo.h	2008-06-12 13:05:14.000000000 -0500
@@ -0,0 +1,218 @@
+/*
+ * linux/drivers/char/hpilo.h
+ *
+ * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
+ *	David Altobelli <david.altobelli@hp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __HPILO_H
+#define __HPILO_H
+
+#define ILO_NAME "HP iLO Channel Interface"
+
+/* max number of open channel control blocks per device, hw limited to 32 */
+#define MAX_CCB		8
+/* max number of supported devices */
+#define MAX_ILO_DEV	1
+/* max number of files */
+#define MAX_OPEN	MAX_CCB * MAX_ILO_DEV
+
+/*
+ * Per device, used to track global memory allocations.
+ */
+struct ilo_hwinfo {
+	/* mmio registers on device */
+	char __iomem *mmio_vaddr;
+
+	/* doorbell registers on device */
+	char __iomem *db_vaddr;
+
+	/* shared memory on device used for channel control blocks */
+	char __iomem *ram_vaddr;
+
+	/* files corresponding to this device */
+	struct ccb_data *ccb_alloc[MAX_CCB];
+
+	struct pci_dev *ilo_dev;
+
+	spinlock_t alloc_lock;
+	spinlock_t fifo_lock;
+
+	struct cdev cdev;
+};
+
+/* offset from mmio_vaddr */
+#define DB_OUT		0xD4
+/* check for global reset condition */
+#define IS_DEVICE_RESET(hw) (ioread32(&(hw)->mmio_vaddr[DB_OUT]) & (1 << 26))
+/* clear the device (reset bits, pending channel entries) */
+#define CLEAR_DEVICE(hw)    (iowrite32(-1, &(hw)->mmio_vaddr[DB_OUT]))
+
+/*
+ * Channel control block. Used to manage hardware queues.
+ * The format must match hw's version.  The hw ccb is 128 bytes,
+ * but the context area shouldn't be touched by the driver.
+ */
+#define ILOSW_CCB_SZ	64
+#define ILOHW_CCB_SZ 	128
+struct ccb {
+	union {
+		char *send_fifobar;
+		u64 padding1;
+	} ccb_u1;
+	union {
+		char *send_desc;
+		u64 padding2;
+	} ccb_u2;
+	u64 send_ctrl;
+
+	union {
+		char *recv_fifobar;
+		u64 padding3;
+	} ccb_u3;
+	union {
+		char *recv_desc;
+		u64 padding4;
+	} ccb_u4;
+	u64 recv_ctrl;
+
+	union {
+		char __iomem *db_base;
+		u64 padding5;
+	} ccb_u5;
+
+	u64 channel;
+
+	/* unused context area (64 bytes) */
+};
+
+/* ccb queue parameters */
+#define SENDQ		1
+#define RECVQ 		2
+#define NR_QENTRY    	4
+#define L2_QENTRY_SZ 	12
+#define DESC_MEM_SZ(_descs) ((_descs) << L2_QENTRY_SZ)
+
+/* ccb ctrl bitfields */
+#define CTRL_BITPOS_L2SZ             0
+#define CTRL_BITPOS_FIFOINDEXMASK    4
+#define CTRL_BITPOS_DESCLIMIT        18
+#define CTRL_BITPOS_A                30
+#define CTRL_BITPOS_G                31
+
+#define CTRL_SET(_c, _l, _f, _d, _a, _g)	 \
+	((_c) =			 	 	 \
+	 (((_l) << CTRL_BITPOS_L2SZ)		|\
+	  ((_f) << CTRL_BITPOS_FIFOINDEXMASK)	|\
+	  ((_d) << CTRL_BITPOS_DESCLIMIT)	|\
+	  ((_a) << CTRL_BITPOS_A)		|\
+	  ((_g) << CTRL_BITPOS_G)))
+
+/* ccb doorbell macros */
+#define L2_DB_SIZE		14
+#define ONE_DB_SIZE		(1 << L2_DB_SIZE)
+#define DOORBELL_SET(_ccb)	(iowrite8(1, (_ccb)->ccb_u5.db_base))
+#define DOORBELL_CLR(_ccb)	(iowrite8(2, (_ccb)->ccb_u5.db_base))
+
+/*
+ * Per fd structure used to track the ccb allocated to that dev file.
+ */
+struct ccb_data {
+	/* software version of ccb, using virtual addrs */
+	struct ccb  driver_ccb;
+
+	/* hardware version of ccb, using physical addrs */
+	struct ccb  ilo_ccb;
+
+	/* hardware ccb is written to this shared mapped device memory */
+	struct ccb __iomem *mapped_ccb;
+
+	/* dma'able memory used for send/recv queues */
+	void       *dma_va;
+	dma_addr_t  dma_pa;
+	size_t      dma_size;
+
+	/* pointer to hardware device info */
+	struct ilo_hwinfo *ilo_hw;
+
+	/* usage count, to allow for shared ccb's */
+	int	    ccb_cnt;
+
+	/* open wanted exclusive access to this ccb */
+	int	    ccb_excl;
+};
+
+/*
+ * FIFO queue structure, shared with hw.
+ */
+#define ILO_START_ALIGN	4096
+#define ILO_CACHE_SZ 	 128
+struct fifo {
+    u64 nrents;	/* user requested number of fifo entries */
+    u64 imask;  /* mask to extract valid fifo index */
+    u64 merge;	/*  O/C bits to merge in during enqueue operation */
+    u64 reset;	/* set to non-zero when the target device resets */
+    u8  pad_0[ILO_CACHE_SZ - (sizeof(u64) * 4)];
+
+    u64 head;
+    u8  pad_1[ILO_CACHE_SZ - (sizeof(u64))];
+
+    u64 tail;
+    u8  pad_2[ILO_CACHE_SZ - (sizeof(u64))];
+
+    volatile u64 fifobar[1];
+};
+
+/* convert between struct fifo, and the fifobar, which is saved in the ccb */
+#define FIFOHANDLESIZE (sizeof(struct fifo) - sizeof(u64))
+#define FIFOBARTOHANDLE(_fifo) \
+	((struct fifo *)(((char *)(_fifo)) - FIFOHANDLESIZE))
+
+/* set a flag indicating this channel needs a reset */
+#define SET_CHANNEL_RESET(_ccb) \
+	(FIFOBARTOHANDLE((_ccb)->ccb_u1.send_fifobar)->reset = 1)
+
+/* check for this particular channel needing a reset */
+#define IS_CHANNEL_RESET(_ccb) \
+	(FIFOBARTOHANDLE((_ccb)->ccb_u1.send_fifobar)->reset)
+
+/* overall size of a fifo is determined by the number of entries it contains */
+#define FIFO_SZ(_num) (((_num)*sizeof(u64)) + FIFOHANDLESIZE)
+
+/* the number of qwords to consume from the entry descriptor */
+#define ENTRY_BITPOS_QWORDS      0
+/* descriptor index number (within a specified queue) */
+#define ENTRY_BITPOS_DESCRIPTOR  10
+/* state bit, fifo entry consumed by consumer */
+#define ENTRY_BITPOS_C           22
+/* state bit, fifo entry is occupied */
+#define ENTRY_BITPOS_O           23
+
+#define ENTRY_BITS_QWORDS        10
+#define ENTRY_BITS_DESCRIPTOR    12
+#define ENTRY_BITS_C             1
+#define ENTRY_BITS_O             1
+#define ENTRY_BITS_TOTAL	\
+	(ENTRY_BITS_C + ENTRY_BITS_O + \
+	 ENTRY_BITS_QWORDS + ENTRY_BITS_DESCRIPTOR)
+
+/* extract various entry fields */
+#define ENTRY_MASK ((1 << ENTRY_BITS_TOTAL) - 1)
+#define ENTRY_MASK_C (((1 << ENTRY_BITS_C) - 1) << ENTRY_BITPOS_C)
+#define ENTRY_MASK_O (((1 << ENTRY_BITS_O) - 1) << ENTRY_BITPOS_O)
+#define ENTRY_MASK_QWORDS \
+	(((1 << ENTRY_BITS_QWORDS) - 1) << ENTRY_BITPOS_QWORDS)
+#define ENTRY_MASK_DESCRIPTOR \
+	(((1 << ENTRY_BITS_DESCRIPTOR) - 1) << ENTRY_BITPOS_DESCRIPTOR)
+
+#define ENTRY_MASK_NOSTATE (ENTRY_MASK >> (ENTRY_BITS_C + ENTRY_BITS_O))
+
+#define GETQWORDS(_e) (((_e) & ENTRY_MASK_QWORDS) >> ENTRY_BITPOS_QWORDS)
+#define GETDESC(_e) (((_e) & ENTRY_MASK_DESCRIPTOR) >> ENTRY_BITPOS_DESCRIPTOR)
+
+#define QWORDS(_B) (((_B) & 7) ? (((_B) >> 3) + 1) : ((_B) >> 3))
+
+#endif /* __HPILO_H */
diff -urpN linux-2.6.25.orig/drivers/char/Kconfig linux-2.6.25/drivers/char/Kconfig
--- linux-2.6.25.orig/drivers/char/Kconfig	2008-04-30 16:42:55.000000000 -0500
+++ linux-2.6.25/drivers/char/Kconfig	2008-05-23 08:47:15.000000000 -0500
@@ -1049,5 +1049,18 @@ config DEVPORT
 
 source "drivers/s390/char/Kconfig"
 
+config HP_ILO
+	tristate "Channel interface driver for hp iLO/iLO2 processor"
+	default n
+	help
+	  The channel interface driver allows applications to communicate
+	  with iLO/iLO2 management processors present on HP ProLiant
+	  servers.  Upon loading, the driver exports /dev/hpilo_ccbN files, 
+	  which can be used to gather data from the management processor,
+	  via read and write system calls.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hpilo.
+	
 endmenu
 
diff -urpN linux-2.6.25.orig/drivers/char/Makefile linux-2.6.25/drivers/char/Makefile
--- linux-2.6.25.orig/drivers/char/Makefile	2008-04-30 16:42:56.000000000 -0500
+++ linux-2.6.25/drivers/char/Makefile	2008-05-22 16:22:28.000000000 -0500
@@ -97,6 +97,7 @@ obj-$(CONFIG_CS5535_GPIO)	+= cs5535_gpio
 obj-$(CONFIG_GPIO_VR41XX)	+= vr41xx_giu.o
 obj-$(CONFIG_GPIO_TB0219)	+= tb0219.o
 obj-$(CONFIG_TELCLOCK)		+= tlclk.o
+obj-$(CONFIG_HP_ILO)		+= hpilo.o
 
 obj-$(CONFIG_MWAVE)		+= mwave/
 obj-$(CONFIG_AGP)		+= agp/