x86/kernel/pci-calgary_64.c

/*
 * Derived from arch/powerpc/kernel/iommu.c
 *
 * Copyright IBM Corporation, 2006-2007
 * Copyright (C) 2006  Jon Mason <jdmason@kudzu.us>
 *
 * Author: Jon Mason <jdmason@kudzu.us>
 * Author: Muli Ben-Yehuda <muli@il.ibm.com>

 * 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/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/crash_dump.h>
#include <linux/dma-mapping.h>
#include <linux/bitmap.h>
#include <linux/pci_ids.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/scatterlist.h>
#include <linux/iommu-helper.h>

#include <asm/iommu.h>
#include <asm/calgary.h>
#include <asm/tce.h>
#include <asm/pci-direct.h>
#include <asm/system.h>
#include <asm/dma.h>
#include <asm/rio.h>
#include <asm/bios_ebda.h>
#include <asm/x86_init.h>
#include <asm/iommu_table.h>

#ifdef CONFIG_CALGARY_IOMMU_ENABLED_BY_DEFAULT
int use_calgary __read_mostly = 1;
#else
int use_calgary __read_mostly = 0;
#endif /* CONFIG_CALGARY_DEFAULT_ENABLED */

#define PCI_DEVICE_ID_IBM_CALGARY 0x02a1
#define PCI_DEVICE_ID_IBM_CALIOC2 0x0308

/* register offsets inside the host bridge space */
#define CALGARY_CONFIG_REG	0x0108
#define PHB_CSR_OFFSET		0x0110 /* Channel Status */
#define PHB_PLSSR_OFFSET	0x0120
#define PHB_CONFIG_RW_OFFSET	0x0160
#define PHB_IOBASE_BAR_LOW	0x0170
#define PHB_IOBASE_BAR_HIGH	0x0180
#define PHB_MEM_1_LOW		0x0190
#define PHB_MEM_1_HIGH		0x01A0
#define PHB_IO_ADDR_SIZE	0x01B0
#define PHB_MEM_1_SIZE		0x01C0
#define PHB_MEM_ST_OFFSET	0x01D0
#define PHB_AER_OFFSET		0x0200
#define PHB_CONFIG_0_HIGH	0x0220
#define PHB_CONFIG_0_LOW	0x0230
#define PHB_CONFIG_0_END	0x0240
#define PHB_MEM_2_LOW		0x02B0
#define PHB_MEM_2_HIGH		0x02C0
#define PHB_MEM_2_SIZE_HIGH	0x02D0
#define PHB_MEM_2_SIZE_LOW	0x02E0
#define PHB_DOSHOLE_OFFSET	0x08E0

/* CalIOC2 specific */
#define PHB_SAVIOR_L2		0x0DB0
#define PHB_PAGE_MIG_CTRL	0x0DA8
#define PHB_PAGE_MIG_DEBUG	0x0DA0
#define PHB_ROOT_COMPLEX_STATUS 0x0CB0

/* PHB_CONFIG_RW */
#define PHB_TCE_ENABLE		0x20000000
#define PHB_SLOT_DISABLE	0x1C000000
#define PHB_DAC_DISABLE		0x01000000
#define PHB_MEM2_ENABLE		0x00400000
#define PHB_MCSR_ENABLE		0x00100000
/* TAR (Table Address Register) */
#define TAR_SW_BITS		0x0000ffffffff800fUL
#define TAR_VALID		0x0000000000000008UL
/* CSR (Channel/DMA Status Register) */
#define CSR_AGENT_MASK		0xffe0ffff
/* CCR (Calgary Configuration Register) */
#define CCR_2SEC_TIMEOUT	0x000000000000000EUL
/* PMCR/PMDR (Page Migration Control/Debug Registers */
#define PMR_SOFTSTOP		0x80000000
#define PMR_SOFTSTOPFAULT	0x40000000
#define PMR_HARDSTOP		0x20000000

/*
 * The maximum PHB bus number.
 * x3950M2 (rare): 8 chassis, 48 PHBs per chassis = 384
 * x3950M2: 4 chassis, 48 PHBs per chassis        = 192
 * x3950 (PCIE): 8 chassis, 32 PHBs per chassis   = 256
 * x3950 (PCIX): 8 chassis, 16 PHBs per chassis   = 128
 */
#define MAX_PHB_BUS_NUM		256

#define PHBS_PER_CALGARY	  4

/* register offsets in Calgary's internal register space */
static const unsigned long tar_offsets[] = {
	0x0580 /* TAR0 */,
	0x0588 /* TAR1 */,
	0x0590 /* TAR2 */,
	0x0598 /* TAR3 */
};

static const unsigned long split_queue_offsets[] = {
	0x4870 /* SPLIT QUEUE 0 */,
	0x5870 /* SPLIT QUEUE 1 */,
	0x6870 /* SPLIT QUEUE 2 */,
	0x7870 /* SPLIT QUEUE 3 */
};

static const unsigned long phb_offsets[] = {
	0x8000 /* PHB0 */,
	0x9000 /* PHB1 */,
	0xA000 /* PHB2 */,
	0xB000 /* PHB3 */
};

/* PHB debug registers */

static const unsigned long phb_debug_offsets[] = {
	0x4000	/* PHB 0 DEBUG */,
	0x5000	/* PHB 1 DEBUG */,
	0x6000	/* PHB 2 DEBUG */,
	0x7000	/* PHB 3 DEBUG */
};

/*
 * STUFF register for each debug PHB,
 * byte 1 = start bus number, byte 2 = end bus number
 */

#define PHB_DEBUG_STUFF_OFFSET	0x0020

#define EMERGENCY_PAGES 32 /* = 128KB */

unsigned int specified_table_size = TCE_TABLE_SIZE_UNSPECIFIED;
static int translate_empty_slots __read_mostly = 0;
static int calgary_detected __read_mostly = 0;

static struct rio_table_hdr	*rio_table_hdr __initdata;
static struct scal_detail	*scal_devs[MAX_NUMNODES] __initdata;
static struct rio_detail	*rio_devs[MAX_NUMNODES * 4] __initdata;

struct calgary_bus_info {
	void *tce_space;
	unsigned char translation_disabled;
	signed char phbid;
	void __iomem *bbar;
};

static void calgary_handle_quirks(struct iommu_table *tbl, struct pci_dev *dev);
static void calgary_tce_cache_blast(struct iommu_table *tbl);
static void calgary_dump_error_regs(struct iommu_table *tbl);
static void calioc2_handle_quirks(struct iommu_table *tbl, struct pci_dev *dev);
static void calioc2_tce_cache_blast(struct iommu_table *tbl);
static void calioc2_dump_error_regs(struct iommu_table *tbl);
static void calgary_init_bitmap_from_tce_table(struct iommu_table *tbl);
static void get_tce_space_from_tar(void);

static struct cal_chipset_ops calgary_chip_ops = {
	.handle_quirks = calgary_handle_quirks,
	.tce_cache_blast = calgary_tce_cache_blast,
	.dump_error_regs = calgary_dump_error_regs
};

static struct cal_chipset_ops calioc2_chip_ops = {
	.handle_quirks = calioc2_handle_quirks,
	.tce_cache_blast = calioc2_tce_cache_blast,
	.dump_error_regs = calioc2_dump_error_regs
};

static struct calgary_bus_info bus_info[MAX_PHB_BUS_NUM] = { { NULL, 0, 0 }, };

static inline int translation_enabled(struct iommu_table *tbl)
{
	/* only PHBs with translation enabled have an IOMMU table */
	return (tbl != NULL);
}

static void iommu_range_reserve(struct iommu_table *tbl,
	unsigned long start_addr, unsigned int npages)
{
	unsigned long index;
	unsigned long end;
	unsigned long flags;

	index = start_addr >> PAGE_SHIFT;

	/* bail out if we're asked to reserve a region we don't cover */
	if (index >= tbl->it_size)
		return;

	end = index + npages;
	if (end > tbl->it_size) /* don't go off the table */
		end = tbl->it_size;

	spin_lock_irqsave(&tbl->it_lock, flags);

	bitmap_set(tbl->it_map, index, npages);

	spin_unlock_irqrestore(&tbl->it_lock, flags);
}

static unsigned long iommu_range_alloc(struct device *dev,
				       struct iommu_table *tbl,
				       unsigned int npages)
{
	unsigned long flags;
	unsigned long offset;
	unsigned long boundary_size;

	boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
			      PAGE_SIZE) >> PAGE_SHIFT;

	BUG_ON(npages == 0);

	spin_lock_irqsave(&tbl->it_lock, flags);

	offset = iommu_area_alloc(tbl->it_map, tbl->it_size, tbl->it_hint,
				  npages, 0, boundary_size, 0);
	if (offset == ~0UL) {
		tbl->chip_ops->tce_cache_blast(tbl);

		offset = iommu_area_alloc(tbl->it_map, tbl->it_size, 0,
					  npages, 0, boundary_size, 0);
		if (offset == ~0UL) {
			printk(KERN_WARNING "Calgary: IOMMU full.\n");
			spin_unlock_irqrestore(&tbl->it_lock, flags);
			if (panic_on_overflow)
				panic("Calgary: fix the allocator.\n");
			else
				return DMA_ERROR_CODE;
		}
	}

	tbl->it_hint = offset + npages;
	BUG_ON(tbl->it_hint > tbl->it_size);

	spin_unlock_irqrestore(&tbl->it_lock, flags);

	return offset;
}

static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
			      void *vaddr, unsigned int npages, int direction)
{
	unsigned long entry;
	dma_addr_t ret;

	entry = iommu_range_alloc(dev, tbl, npages);

	if (unlikely(entry == DMA_ERROR_CODE)) {
		printk(KERN_WARNING "Calgary: failed to allocate %u pages in "
		       "iommu %p\n", npages, tbl);
		return DMA_ERROR_CODE;
	}

	/* set the return dma address */
	ret = (entry << PAGE_SHIFT) | ((unsigned long)vaddr & ~PAGE_MASK);

	/* put the TCEs in the HW table */
	tce_build(tbl, entry, npages, (unsigned long)vaddr & PAGE_MASK,
		  direction);
	return ret;
}

static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
	unsigned int npages)
{
	unsigned long entry;
	unsigned long badend;
	unsigned long flags;

	/* were we called with bad_dma_address? */
	badend = DMA_ERROR_CODE + (EMERGENCY_PAGES * PAGE_SIZE);
	if (unlikely((dma_addr >= DMA_ERROR_CODE) && (dma_addr < badend))) {
		WARN(1, KERN_ERR "Calgary: driver tried unmapping bad DMA "
		       "address 0x%Lx\n", dma_addr);
		return;
	}

	entry = dma_addr >> PAGE_SHIFT;

	BUG_ON(entry + npages > tbl->it_size);

	tce_free(tbl, entry, npages);

	spin_lock_irqsave(&tbl->it_lock, flags);

	bitmap_clear(tbl->it_map, entry, npages);

	spin_unlock_irqrestore(&tbl->it_lock, flags);
}

static inline struct iommu_table *find_iommu_table(struct device *dev)
{
	struct pci_dev *pdev;
	struct pci_bus *pbus;
	struct iommu_table *tbl;

	pdev = to_pci_dev(dev);

	/* search up the device tree for an iommu */
	pbus = pdev->bus;
	do {
		tbl = pci_iommu(pbus);
		if (tbl && tbl->it_busno == pbus->number)
			break;
		tbl = NULL;
		pbus = pbus->parent;
	} while (pbus);

	BUG_ON(tbl && (tbl->it_busno != pbus->number));

	return tbl;
}

static void calgary_unmap_sg(struct device *dev, struct scatterlist *sglist,
			     int nelems,enum dma_data_direction dir,
			     struct dma_attrs *attrs)
{
	struct iommu_table *tbl = find_iommu_table(dev);
	struct scatterlist *s;
	int i;

	if (!translation_enabled(tbl))
		return;

	for_each_sg(sglist, s, nelems, i) {
		unsigned int npages;
		dma_addr_t dma = s->dma_address;
		unsigned int dmalen = s->dma_length;

		if (dmalen == 0)
			break;

		npages = iommu_num_pages(dma, dmalen, PAGE_SIZE);
		iommu_free(tbl, dma, npages);
	}
}

static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
			  int nelems, enum dma_data_direction dir,
			  struct dma_attrs *attrs)
{
	struct iommu_table *tbl = find_iommu_table(dev);
	struct scatterlist *s;
	unsigned long vaddr;
	unsigned int npages;
	unsigned long entry;
	int i;

	for_each_sg(sg, s, nelems, i) {
		BUG_ON(!sg_page(s));

		vaddr = (unsigned long) sg_virt(s);
		npages = iommu_num_pages(vaddr, s->length, PAGE_SIZE);

		entry = iommu_range_alloc(dev, tbl, npages);
		if (entry == DMA_ERROR_CODE) {
			/* makes sure unmap knows to stop */
			s->dma_length = 0;
			goto error;
		}

		s->dma_address = (entry << PAGE_SHIFT) | s->offset;

		/* insert into HW table */
		tce_build(tbl, entry, npages, vaddr & PAGE_MASK, dir);

		s->dma_length = s->length;
	}

	return nelems;
error:
	calgary_unmap_sg(dev, sg, nelems, dir, NULL);
	for_each_sg(sg, s, nelems, i) {
		sg->dma_address = DMA_ERROR_CODE;
		sg->dma_length = 0;
	}
	return 0;
}

static dma_addr_t calgary_map_page(struct device *dev, struct page *page,
				   unsigned long offset, size_t size,
				   enum dma_data_direction dir,
				   struct dma_attrs *attrs)
{
	void *vaddr = page_address(page) + offset;
	unsigned long uaddr;
	unsigned int npages;
	struct iommu_table *tbl = find_iommu_table(dev);

	uaddr = (unsigned long)vaddr;
	npages = iommu_num_pages(uaddr, size, PAGE_SIZE);

	return iommu_alloc(dev, tbl, vaddr, npages, dir);
}

static void calgary_unmap_page(struct device *dev, dma_addr_t dma_addr,
			       size_t size, enum dma_data_direction dir,
			       struct dma_attrs *attrs)
{
	struct iommu_table *tbl = find_iommu_table(dev);
	unsigned int npages;

	npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
	iommu_free(tbl, dma_addr, npages);
}

static void* calgary_alloc_coherent(struct device *dev, size_t size,
	dma_addr_t *dma_handle, gfp_t flag)
{
	void *ret = NULL;
	dma_addr_t mapping;
	unsigned int npages, order;
	struct iommu_table *tbl = find_iommu_table(dev);

	size = PAGE_ALIGN(size); /* size rounded up to full pages */
	npages = size >> PAGE_SHIFT;
	order = get_order(size);

	flag &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);

	/* alloc enough pages (and possibly more) */
	ret = (void *)__get_free_pages(flag, order);
	if (!ret)
		goto error;
	memset(ret, 0, size);

	/* set up tces to cover the allocated range */
	mapping = iommu_alloc(dev, tbl, ret, npages, DMA_BIDIRECTIONAL);
	if (mapping == DMA_ERROR_CODE)
		goto free;
	*dma_handle = mapping;
	return ret;
free:
	free_pages((unsigned long)ret, get_order(size));
	ret = NULL;
error:
	return ret;
}

static void calgary_free_coherent(struct device *dev, size_t size,
				  void *vaddr, dma_addr_t dma_handle)
{
	unsigned int npages;
	struct iommu_table *tbl = find_iommu_table(dev);

	size = PAGE_ALIGN(size);
	npages = size >> PAGE_SHIFT;

	iommu_free(tbl, dma_handle, npages);
	free_pages((unsigned long)vaddr, get_order(size));
}

static struct dma_map_ops calgary_dma_ops = {
	.alloc_coherent = calgary_alloc_coherent,
	.free_coherent = calgary_free_coherent,
	.map_sg = calgary_map_sg,
	.unmap_sg = calgary_unmap_sg,
	.map_page = calgary_map_page,
	.unmap_page = calgary_unmap_page,
};

static inline void __iomem * busno_to_bbar(unsigned char num)
{
	return bus_info[num].bbar;
}

static inline int busno_to_phbid(unsigned char num)
{
	return bus_info[num].phbid;
}

static inline unsigned long split_queue_offset(unsigned char num)
{
	size_t idx = busno_to_phbid(num);

	return split_queue_offsets[idx];
}

static inline unsigned long tar_offset(unsigned char num)
{
	size_t idx = busno_to_phbid(num);

	return tar_offsets[idx];
}

static inline unsigned long phb_offset(unsigned char num)
{
	size_t idx = busno_to_phbid(num);

	return phb_offsets[idx];
}

static inline void __iomem* calgary_reg(void __iomem *bar, unsigned long offset)
{
	unsigned long target = ((unsigned long)bar) | offset;
	return (void __iomem*)target;
}

static inline int is_calioc2(unsigned short device)
{
	return (device == PCI_DEVICE_ID_IBM_CALIOC2);
}

static inline int is_calgary(unsigned short device)
{
	return (device == PCI_DEVICE_ID_IBM_CALGARY);
}

static inline int is_cal_pci_dev(unsigned short device)
{
	return (is_calgary(device) || is_calioc2(device));
}

static void calgary_tce_cache_blast(struct iommu_table *tbl)
{
	u64 val;
	u32 aer;
	int i = 0;
	void __iomem *bbar = tbl->bbar;
	void __iomem *target;

	/* disable arbitration on the bus */
	target = calgary_reg(bbar, phb_offset(tbl->it_busno) | PHB_AER_OFFSET);
	aer = readl(target);
	writel(0, target);

	/* read plssr to ensure it got there */
	target = calgary_reg(bbar, phb_offset(tbl->it_busno) | PHB_PLSSR_OFFSET);
	val = readl(target);

	/* poll split queues until all DMA activity is done */
	target = calgary_reg(bbar, split_queue_offset(tbl->it_busno));
	do {
		val = readq(target);
		i++;
	} while ((val & 0xff) != 0xff && i < 100);
	if (i == 100)
		printk(KERN_WARNING "Calgary: PCI bus not quiesced, "
		       "continuing anyway\n");

	/* invalidate TCE cache */
	target = calgary_reg(bbar, tar_offset(tbl->it_busno));
	writeq(tbl->tar_val, target);

	/* enable arbitration */
	target = calgary_reg(bbar, phb_offset(tbl->it_busno) | PHB_AER_OFFSET);
	writel(aer, target);
	(void)readl(target); /* flush */
}

static void calioc2_tce_cache_blast(struct iommu_table *tbl)
{
	void __iomem *bbar = tbl->bbar;
	void __iomem *target;
	u64 val64;
	u32 val;
	int i = 0;
	int count = 1;
	unsigned char bus = tbl->it_busno;

begin:
	printk(KERN_DEBUG "Calgary: CalIOC2 bus 0x%x entering tce cache blast "
	       "sequence - count %d\n", bus, count);

	/* 1. using the Page Migration Control reg set SoftStop */
	target = calgary_reg(bbar, phb_offset(bus) | PHB_PAGE_MIG_CTRL);
	val = be32_to_cpu(readl(target));
	printk(KERN_DEBUG "1a. read 0x%x [LE] from %p\n", val, target);
	val |= PMR_SOFTSTOP;
	printk(KERN_DEBUG "1b. writing 0x%x [LE] to %p\n", val, target);
	writel(cpu_to_be32(val), target);

	/* 2. poll split queues until all DMA activity is done */
	printk(KERN_DEBUG "2a. starting to poll split queues\n");
	target = calgary_reg(bbar, split_queue_offset(bus));
	do {
		val64 = readq(target);
		i++;
	} while ((val64 & 0xff) != 0xff && i < 100);
	if (i == 100)
		printk(KERN_WARNING "CalIOC2: PCI bus not quiesced, "
		       "continuing anyway\n");

	/* 3. poll Page Migration DEBUG for SoftStopFault */
	target = calgary_reg(bbar, phb_offset(bus) | PHB_PAGE_MIG_DEBUG);
	val = be32_to_cpu(readl(target));
	printk(KERN_DEBUG "3. read 0x%x [LE] from %p\n", val, target);

	/* 4. if SoftStopFault - goto (1) */
	if (val & PMR_SOFTSTOPFAULT) {
		if (++count < 100)
			goto begin;
		else {
			printk(KERN_WARNING "CalIOC2: too many SoftStopFaults, "
			       "aborting TCE cache flush sequence!\n");
			return; /* pray for the best */
		}
	}

	/* 5. Slam into HardStop by reading PHB_PAGE_MIG_CTRL */
	target = calgary_reg(bbar, phb_offset(bus) | PHB_PAGE_MIG_CTRL);
	printk(KERN_DEBUG "5a. slamming into HardStop by reading %p\n", target);
	val = be32_to_cpu(readl(target));
	printk(KERN_DEBUG "5b. read 0x%x [LE] from %p\n", val, target);
	target = calgary_reg(bbar, phb_offset(bus) | PHB_PAGE_MIG_DEBUG);
	val = be32_to_cpu(readl(target));
	printk(KERN_DEBUG "5c. read 0x%x [LE] from %p (debug)\n", val, target);

	/* 6. invalidate TCE cache */
	printk(KERN_DEBUG "6. invalidating TCE cache\n");
	target = calgary_reg(bbar, tar_offset(bus));
	writeq(tbl->tar_val, target);

	/* 7. Re-read PMCR */
	printk(KERN_DEBUG "7a. Re-reading PMCR\n");
	target = calgary_reg(bbar, phb_offset(bus) | PHB_PAGE_MIG_CTRL);
	val = be32_to_cpu(readl(target));
	printk(KERN_DEBUG "7b. read 0x%x [LE] from %p\n", val, target);

	/* 8. Remove HardStop */
	printk(KERN_DEBUG "8a. removing HardStop from PMCR\n");
	target = calgary_reg(bbar, phb_offset(bus) | PHB_PAGE_MIG_CTRL);
	val = 0;
	printk(KERN_DEBUG "8b. writing 0x%x [LE] to %p\n", val, target);
	writel(cpu_to_be32(val), target);
	val = be32_to_cpu(readl(target));
	printk(KERN_DEBUG "8c. read 0x%x [LE] from %p\n", val, target);
}

static void __init calgary_reserve_mem_region(struct pci_dev *dev, u64 start,
	u64 limit)
{
	unsigned int numpages;

	limit = limit | 0xfffff;
	limit++;

	numpages = ((limit - start) >> PAGE_SHIFT);
	iommu_range_reserve(pci_iommu(dev->bus), start, numpages);
}

static void __init calgary_reserve_peripheral_mem_1(struct pci_dev *dev)
{
	void __iomem *target;
	u64 low, high, sizelow;
	u64 start, limit;
	struct iommu_table *tbl = pci_iommu(dev->bus);
	unsigned char busnum = dev->bus->number;
	void __iomem *bbar = tbl->bbar;

	/* peripheral MEM_1 region */
	target = calgary_reg(bbar, phb_offset(busnum) | PHB_MEM_1_LOW);
	low = be32_to_cpu(readl(target));
	target = calgary_reg(bbar, phb_offset(busnum) | PHB_MEM_1_HIGH);
	high = be32_to_cpu(readl(target));
	target = calgary_reg(bbar, phb_offset(busnum) | PHB_MEM_1_SIZE);
	sizelow = be32_to_cpu(readl(target));

	start = (high << 32) | low;
	limit = sizelow;

	calgary_reserve_mem_region(dev, start, limit);
}

static void __init calgary_reserve_peripheral_mem_2(struct pci_dev *dev)
{
	void __iomem *target;
	u32 val32;
	u64 low, high, sizelow, sizehigh;
	u64 start, limit;
	struct iommu_table *tbl = pci_iommu(dev->bus);
	unsigned char busnum = dev->bus->number;
	void __iomem *bbar = tbl->bbar;

	/* is it enabled? */
	target = calgary_reg(bbar, phb_offset(busnum) | PHB_CONFIG_RW_OFFSET);
	val32 = be32_to_cpu(readl(target));
	if (!(val32 & PHB_MEM2_ENABLE))
		return;

	target = calgary_reg(bbar, phb_offset(busnum) | PHB_MEM_2_LOW);
	low = be32_to_cpu(readl(target));
	target = calgary_reg(bbar, phb_offset(busnum) | PHB_MEM_2_HIGH);
	high = be32_to_cpu(readl(target));
	target = calgary_reg(bbar, phb_offset(busnum) | PHB_MEM_2_SIZE_LOW);
	sizelow = be32_to_cpu(readl(target));
	target = calgary_reg(bbar, phb_offset(busnum) | PHB_MEM_2_SIZE_HIGH);
	sizehigh = be32_to_cpu(readl(target));

	start = (high << 32) | low;
	limit = (sizehigh << 32) | sizelow;

	calgary_reserve_mem_region(dev, start, limit);
}

/*
 * some regions of the IO address space do not get translated, so we
 * must not give devices IO addresses in those regions. The regions
 * are the 640KB-1MB region and the two PCI peripheral memory holes.
 * Reserve all of them in the IOMMU bitmap to avoid giving them out
 * later.
 */
static void __init calgary_reserve_regions(struct pci_dev *dev)
{
	unsigned int npages;
	u64 start;
	struct iommu_table *tbl = pci_iommu(dev->bus);

	/* reserve EMERGENCY_PAGES from bad_dma_address and up */
	iommu_range_reserve(tbl, DMA_ERROR_CODE, EMERGENCY_PAGES);

	/* avoid the BIOS/VGA first 640KB-1MB region */
	/* for CalIOC2 - avoid the entire first MB */
	if (is_calgary(dev->device)) {
		start = (640 * 1024);
		npages = ((1024 - 640) * 1024) >> PAGE_SHIFT;
	} else { /* calioc2 */
		start = 0;
		npages = (1 * 1024 * 1024) >> PAGE_SHIFT;
	}
	iommu_range_reserve(tbl, start, npages);

	/* reserve the two PCI peripheral memory regions in IO space */
	calgary_reserve_peripheral_mem_1(dev);
	calgary_reserve_peripheral_mem_2(dev);
}

static int __init calgary_setup_tar(struct pci_dev *dev, void __iomem *bbar)
{
	u64 val64;
	u64 table_phys;
	void __iomem *target;
	int ret;
	struct iommu_table *tbl;

	/* build TCE tables for each PHB */
	ret = build_tce_table(dev, bbar);
	if (ret)
		return ret;

	tbl = pci_iommu(dev->bus);
	tbl->it_base = (unsigned long)bus_info[dev->bus->number].tce_space;

	if (is_kdump_kernel())
		calgary_init_bitmap_from_tce_table(tbl);
	else
		tce_free(tbl, 0, tbl->it_size);

	if (is_calgary(dev->device))
		tbl->chip_ops = &calgary_chip_ops;
	else if (is_calioc2(dev->device))
		tbl->chip_ops = &calioc2_chip_ops;
	else
		BUG();

	calgary_reserve_regions(dev);

	/* set TARs for each PHB */
	target = calgary_reg(bbar, tar_offset(dev->bus->number));
	val64 = be64_to_cpu(readq(target));

	/* zero out all TAR bits under sw control */
	val64 &= ~TAR_SW_BITS;
	table_phys = (u64)__pa(tbl->it_base);

	val64 |= table_phys;

	BUG_ON(specified_table_size > TCE_TABLE_SIZE_8M);
	val64 |= (u64) specified_table_size;

	tbl->tar_val = cpu_to_be64(val64);

	writeq(tbl->tar_val, target);
	readq(target); /* flush */

	return 0;
}

static void __init calgary_free_bus(struct pci_dev *dev)
{
	u64 val64;
	struct iommu_table *tbl = pci_iommu(dev->bus);
	void __iomem *target;
	unsigned int bitmapsz;

	target = calgary_reg(tbl->bbar, tar_offset(dev->bus->number));
	val64 = be64_to_cpu(readq(target));
	val64 &= ~TAR_SW_BITS;
	writeq(cpu_to_be64(val64), target);
	readq(target); /* flush */

	bitmapsz = tbl->it_size / BITS_PER_BYTE;
	free_pages((unsigned long)tbl->it_map, get_order(bitmapsz));
	tbl->it_map = NULL;

	kfree(tbl);

	set_pci_iommu(dev->bus, NULL);

	/* Can't free bootmem allocated memory after system is up :-( */
	bus_info[dev->bus->number].tce_space = NULL;
}

static void calgary_dump_error_regs(struct iommu_table *tbl)
{
	void __iomem *bbar = tbl->bbar;
	void __iomem *target;
	u32 csr, plssr;

	target = calgary_reg(bbar, phb_offset(tbl->it_busno) | PHB_CSR_OFFSET);
	csr = be32_to_cpu(readl(target));

	target = calgary_reg(bbar, phb_offset(tbl->it_busno) | PHB_PLSSR_OFFSET);
	plssr = be32_to_cpu(readl(target));

	/* If no error, the agent ID in the CSR is not valid */
	printk(KERN_EMERG "Calgary: DMA error on Calgary PHB 0x%x, "
	       "0x%08x@CSR 0x%08x@PLSSR\n", tbl->it_busno, csr, plssr);
}

static void calioc2_dump_error_regs(struct iommu_table *tbl)
{
	void __iomem *bbar = tbl->bbar;
	u32 csr, csmr, plssr, mck, rcstat;
	void __iomem *target;
	unsigned long phboff = phb_offset(tbl->it_busno);
	unsigned long erroff;
	u32 errregs[7];
	int i;

	/* dump CSR */
	target = calgary_reg(bbar, phboff | PHB_CSR_OFFSET);
	csr = be32_to_cpu(readl(target));
	/* dump PLSSR */
	target = calgary_reg(bbar, phboff | PHB_PLSSR_OFFSET);
	plssr = be32_to_cpu(readl(target));
	/* dump CSMR */
	target = calgary_reg(bbar, phboff | 0x290);
	csmr = be32_to_cpu(readl(target));
	/* dump mck */
	target = calgary_reg(bbar, phboff | 0x800);
	mck = be32_to_cpu(readl(target));

	printk(KERN_EMERG "Calgary: DMA error on CalIOC2 PHB 0x%x\n",
	       tbl->it_busno);

	printk(KERN_EMERG "Calgary: 0x%08x@CSR 0x%08x@PLSSR 0x%08x@CSMR 0x%08x@MCK\n",
	       csr, plssr, csmr, mck);

	/* dump rest of error regs */
	printk(KERN_EMERG "Calgary: ");
	for (i = 0; i < ARRAY_SIZE(errregs); i++) {
		/* err regs are at 0x810 - 0x870 */
		erroff = (0x810 + (i * 0x10));
		target = calgary_reg(bbar, phboff | erroff);
		errregs[i] = be32_to_cpu(readl(target));
		printk("0x%08x@0x%lx ", errregs[i], erroff);
	}
	printk("\n");

	/* root complex status */
	target = calgary_reg(bbar, phboff | PHB_ROOT_COMPLEX_STATUS);
	rcstat = be32_to_cpu(readl(target));
	printk(KERN_EMERG "Calgary: 0x%08x@0x%x\n", rcstat,
	       PHB_ROOT_COMPLEX_STATUS);
}

static void calgary_watchdog(unsigned long data)
{
	struct pci_dev *dev = (struct pci_dev *)data;
	struct iommu_table *tbl = pci_iommu(dev->bus);
	void __iomem *bbar = tbl->bbar;
	u32 val32;
	void __iomem *target;

	target = calgary_reg(bbar, phb_offset(tbl->it_busno) | PHB_CSR_OFFSET);
	val32 = be32_to_cpu(readl(target));

	/* If no error, the agent ID in the CSR is not valid */
	if (val32 & CSR_AGENT_MASK) {
		tbl->chip_ops->dump_error_regs(tbl);

		/* reset error */
		writel(0, target);

		/* Disable bus that caused the error */
		target = calgary_reg(bbar, phb_offset(tbl->it_busno) |
				     PHB_CONFIG_RW_OFFSET);
		val32 = be32_to_cpu(readl(target));
		val32 |= PHB_SLOT_DISABLE;
		writel(cpu_to_be32(val32), target);
		readl(target); /* flush */
	} else {
		/* Reset the timer */
		mod_timer(&tbl->watchdog_timer, jiffies + 2 * HZ);
	}
}

static void __init calgary_set_split_completion_timeout(void __iomem *bbar,
	unsigned char busnum, unsigned long timeout)
{
	u64 val64;
	void __iomem *target;
	unsigned int phb_shift = ~0; /* silence gcc */
	u64 mask;

	switch (busno_to_phbid(busnum)) {
	case 0: phb_shift = (63 - 19);
		break;
	case 1: phb_shift = (63 - 23);
		break;
	case 2: phb_shift = (63 - 27);
		break;
	case 3: phb_shift = (63 - 35);
		break;
	default:
		BUG_ON(busno_to_phbid(busnum));
	}

	target = calgary_reg(bbar, CALGARY_CONFIG_REG);
	val64 = be64_to_cpu(readq(target));

	/* zero out this PHB's timer bits */
	mask = ~(0xFUL << phb_shift);
	val64 &= mask;
	val64 |= (timeout << phb_shift);
	writeq(cpu_to_be64(val64), target);
	readq(target); /* flush */
}

static void __init calioc2_handle_quirks(struct iommu_table *tbl, struct pci_dev *dev)
{
	unsigned char busnum = dev->bus->number;
	void __iomem *bbar = tbl->bbar;
	void __iomem *target;
	u32 val;

	/*
	 * CalIOC2 designers recommend setting bit 8 in 0xnDB0 to 1
	 */
	target = calgary_reg(bbar, phb_offset(busnum) | PHB_SAVIOR_L2);
	val = cpu_to_be32(readl(target));
	val |= 0x00800000;
	writel(cpu_to_be32(val), target);
}

static void __init calgary_handle_quirks(struct iommu_table *tbl, struct pci_dev *dev)
{
	unsigned char busnum = dev->bus->number;

	/*
	 * Give split completion a longer timeout on bus 1 for aic94xx
	 * http://bugzilla.kernel.org/show_bug.cgi?id=7180
	 */
	if (is_calgary(dev->device) && (busnum == 1))
		calgary_set_split_completion_timeout(tbl->bbar, busnum,
						     CCR_2SEC_TIMEOUT);
}

static void __init calgary_enable_translation(struct pci_dev *dev)
{
	u32 val32;
	unsigned char busnum;
	void __iomem *target;
	void __iomem *bbar;
	struct iommu_table *tbl;

	busnum = dev->bus->number;
	tbl = pci_iommu(dev->bus);
	bbar = tbl->bbar;

	/* enable TCE in PHB Config Register */
	target = calgary_reg(bbar, phb_offset(busnum) | PHB_CONFIG_RW_OFFSET);
	val32 = be32_to_cpu(readl(target));
	val32 |= PHB_TCE_ENABLE | PHB_DAC_DISABLE | PHB_MCSR_ENABLE;

	printk(KERN_INFO "Calgary: enabling translation on %s PHB %#x\n",
	       (dev->device == PCI_DEVICE_ID_IBM_CALGARY) ?
	       "Calgary" : "CalIOC2", busnum);
	printk(KERN_INFO "Calgary: errant DMAs will now be prevented on this "
	       "bus.\n");

	writel(cpu_to_be32(val32), target);
	readl(target); /* flush */

	init_timer(&tbl->watchdog_timer);
	tbl->watchdog_timer.function = &calgary_watchdog;
	tbl->watchdog_timer.data = (unsigned long)dev;
	mod_timer(&tbl->watchdog_timer, jiffies);
}

static void __init calgary_disable_translation(struct pci_dev *dev)
{
	u32 val32;
	unsigned char busnum;
	void __iomem *target;
	void __iomem *bbar;
	struct iommu_table *tbl;

	busnum = dev->bus->number;
	tbl = pci_iommu(dev->bus);
	bbar = tbl->bbar;

	/* disable TCE in PHB Config Register */
	target = calgary_reg(bbar, phb_offset(busnum) | PHB_CONFIG_RW_OFFSET);
	val32 = be32_to_cpu(readl(target));
	val32 &= ~(PHB_TCE_ENABLE | PHB_DAC_DISABLE | PHB_MCSR_ENABLE);

	printk(KERN_INFO "Calgary: disabling translation on PHB %#x!\n", busnum);
	writel(cpu_to_be32(val32), target);
	readl(target); /* flush */

	del_timer_sync(&tbl->watchdog_timer);
}

static void __init calgary_init_one_nontraslated(struct pci_dev *dev)
{
	pci_dev_get(dev);
	set_pci_iommu(dev->bus, NULL);

	/* is the device behind a bridge? */
	if (dev->bus->parent)
		dev->bus->parent->self = dev;
	else
		dev->bus->self = dev;
}

static int __init calgary_init_one(struct pci_dev *dev)
{
	void __iomem *bbar;
	struct iommu_table *tbl;
	int ret;

	bbar = busno_to_bbar(dev->bus->number);
	ret = calgary_setup_tar(dev, bbar);
	if (ret)
		goto done;

	pci_dev_get(dev);

	if (dev->bus->parent) {
		if (dev->bus->parent->self)
			printk(KERN_WARNING "Calgary: IEEEE, dev %p has "
			       "bus->parent->self!\n", dev);
		dev->bus->parent->self = dev;
	} else
		dev->bus->self = dev;

	tbl = pci_iommu(dev->bus);
	tbl->chip_ops->handle_quirks(tbl, dev);

	calgary_enable_translation(dev);

	return 0;

done:
	return ret;
}

static int __init calgary_locate_bbars(void)
{
	int ret;
	int rioidx, phb, bus;
	void __iomem *bbar;
	void __iomem *target;
	unsigned long offset;
	u8 start_bus, end_bus;
	u32 val;

	ret = -ENODATA;
	for (rioidx = 0; rioidx < rio_table_hdr->num_rio_dev; rioidx++) {
		struct rio_detail *rio = rio_devs[rioidx];

		if ((rio->type != COMPAT_CALGARY) && (rio->type != ALT_CALGARY))
			continue;

		/* map entire 1MB of Calgary config space */
		bbar = ioremap_nocache(rio->BBAR, 1024 * 1024);
		if (!bbar)
			goto error;

		for (phb = 0; phb < PHBS_PER_CALGARY; phb++) {
			offset = phb_debug_offsets[phb] | PHB_DEBUG_STUFF_OFFSET;
			target = calgary_reg(bbar, offset);

			val = be32_to_cpu(readl(target));

			start_bus = (u8)((val & 0x00FF0000) >> 16);
			end_bus = (u8)((val & 0x0000FF00) >> 8);

			if (end_bus) {
				for (bus = start_bus; bus <= end_bus; bus++) {
					bus_info[bus].bbar = bbar;
					bus_info[bus].phbid = phb;
				}
			} else {
				bus_info[start_bus].bbar = bbar;
				bus_info[start_bus].phbid = phb;
			}
		}
	}

	return 0;

error:
	/* scan bus_info and iounmap any bbars we previously ioremap'd */
	for (bus = 0; bus < ARRAY_SIZE(bus_info); bus++)
		if (bus_info[bus].bbar)
			iounmap(bus_info[bus].bbar);

	return ret;
}

static int __init calgary_init(void)
{
	int ret;
	struct pci_dev *dev = NULL;
	struct calgary_bus_info *info;

	ret = calgary_locate_bbars();
	if (ret)
		return ret;

	/* Purely for kdump kernel case */
	if (is_kdump_kernel())
		get_tce_space_from_tar();

	do {
		dev = pci_get_device(PCI_VENDOR_ID_IBM, PCI_ANY_ID, dev);
		if (!dev)
			break;
		if (!is_cal_pci_dev(dev->device))
			continue;

		info = &bus_info[dev->bus->number];
		if (info->translation_disabled) {
			calgary_init_one_nontraslated(dev);
			continue;
		}

		if (!info->tce_space && !translate_empty_slots)
			continue;

		ret = calgary_init_one(dev);
		if (ret)
			goto error;
	} while (1);

	dev = NULL;
	for_each_pci_dev(dev) {
		struct iommu_table *tbl;

		tbl = find_iommu_table(&dev->dev);

		if (translation_enabled(tbl))
			dev->dev.archdata.dma_ops = &calgary_dma_ops;
	}

	return ret;

error:
	do {
		dev = pci_get_device(PCI_VENDOR_ID_IBM, PCI_ANY_ID, dev);
		if (!dev)
			break;
		if (!is_cal_pci_dev(dev->device))
			continue;

		info = &bus_info[dev->bus->number];
		if (info->translation_disabled) {
			pci_dev_put(dev);
			continue;
		}
		if (!info->tce_space && !translate_empty_slots)
			continue;

		calgary_disable_translation(dev);
		calgary_free_bus(dev);
		pci_dev_put(dev); /* Undo calgary_init_one()'s pci_dev_get() */
		dev->dev.archdata.dma_ops = NULL;
	} while (1);

	return ret;
}

static inline int __init determine_tce_table_size(u64 ram)
{
	int ret;

	if (specified_table_size != TCE_TABLE_SIZE_UNSPECIFIED)
		return specified_table_size;

	/*
	 * Table sizes are from 0 to 7 (TCE_TABLE_SIZE_64K to
	 * TCE_TABLE_SIZE_8M). Table size 0 has 8K entries and each
	 * larger table size has twice as many entries, so shift the
	 * max ram address by 13 to divide by 8K and then look at the
	 * order of the result to choose between 0-7.
	 */
	ret = get_order(ram >> 13);
	if (ret > TCE_TABLE_SIZE_8M)
		ret = TCE_TABLE_SIZE_8M;

	return ret;
}

static int __init build_detail_arrays(void)
{
	unsigned long ptr;
	unsigned numnodes, i;
	int scal_detail_size, rio_detail_size;

	numnodes = rio_table_hdr->num_scal_dev;
	if (numnodes > MAX_NUMNODES){
		printk(KERN_WARNING
			"Calgary: MAX_NUMNODES too low! Defined as %d, "
			"but system has %d nodes.\n",
			MAX_NUMNODES, numnodes);
		return -ENODEV;
	}

	switch (rio_table_hdr->version){
	case 2:
		scal_detail_size = 11;
		rio_detail_size = 13;
		break;
	case 3:
		scal_detail_size = 12;
		rio_detail_size = 15;
		break;
	default:
		printk(KERN_WARNING
		       "Calgary: Invalid Rio Grande Table Version: %d\n",
		       rio_table_hdr->version);
		return -EPROTO;
	}

	ptr = ((unsigned long)rio_table_hdr) + 3;
	for (i = 0; i < numnodes; i++, ptr += scal_detail_size)
		scal_devs[i] = (struct scal_detail *)ptr;

	for (i = 0; i < rio_table_hdr->num_rio_dev;
		    i++, ptr += rio_detail_size)
		rio_devs[i] = (struct rio_detail *)ptr;

	return 0;
}

static int __init calgary_bus_has_devices(int bus, unsigned short pci_dev)
{
	int dev;
	u32 val;

	if (pci_dev == PCI_DEVICE_ID_IBM_CALIOC2) {
		/*
		 * FIXME: properly scan for devices across the
		 * PCI-to-PCI bridge on every CalIOC2 port.
		 */
		return 1;
	}

	for (dev = 1; dev < 8; dev++) {
		val = read_pci_config(bus, dev, 0, 0);
		if (val != 0xffffffff)
			break;
	}
	return (val != 0xffffffff);
}

/*
 * calgary_init_bitmap_from_tce_table():
 * Function for kdump case. In the second/kdump kernel initialize
 * the bitmap based on the tce table entries obtained from first kernel
 */
static void calgary_init_bitmap_from_tce_table(struct iommu_table *tbl)
{
	u64 *tp;
	unsigned int index;
	tp = ((u64 *)tbl->it_base);
	for (index = 0 ; index < tbl->it_size; index++) {
		if (*tp != 0x0)
			set_bit(index, tbl->it_map);
		tp++;
	}
}

/*
 * get_tce_space_from_tar():
 * Function for kdump case. Get the tce tables from first kernel
 * by reading the contents of the base address register of calgary iommu
 */
static void __init get_tce_space_from_tar(void)
{
	int bus;
	void __iomem *target;
	unsigned long tce_space;

	for (bus = 0; bus < MAX_PHB_BUS_NUM; bus++) {
		struct calgary_bus_info *info = &bus_info[bus];
		unsigned short pci_device;
		u32 val;

		val = read_pci_config(bus, 0, 0, 0);
		pci_device = (val & 0xFFFF0000) >> 16;

		if (!is_cal_pci_dev(pci_device))
			continue;
		if (info->translation_disabled)
			continue;

		if (calgary_bus_has_devices(bus, pci_device) ||
						translate_empty_slots) {
			target = calgary_reg(bus_info[bus].bbar,
						tar_offset(bus));
			tce_space = be64_to_cpu(readq(target));
			tce_space = tce_space & TAR_SW_BITS;

			tce_space = tce_space & (~specified_table_size);
			info->tce_space = (u64 *)__va(tce_space);
		}
	}
	return;
}

static int __init calgary_iommu_init(void)
{
	int ret;

	/* ok, we're trying to use Calgary - let's roll */
	printk(KERN_INFO "PCI-DMA: Using Calgary IOMMU\n");

	ret = calgary_init();
	if (ret) {
		printk(KERN_ERR "PCI-DMA: Calgary init failed %d, "
		       "falling back to no_iommu\n", ret);
		return ret;
	}

	return 0;
}

int __init detect_calgary(void)
{
	int bus;
	void *tbl;
	int calgary_found = 0;
	unsigned long ptr;
	unsigned int offset, prev_offset;
	int ret;

	/*
	 * if the user specified iommu=off or iommu=soft or we found
	 * another HW IOMMU already, bail out.
	 */
	if (no_iommu || iommu_detected)
		return -ENODEV;

	if (!use_calgary)
		return -ENODEV;

	if (!early_pci_allowed())
		return -ENODEV;

	printk(KERN_DEBUG "Calgary: detecting Calgary via BIOS EBDA area\n");

	ptr = (unsigned long)phys_to_virt(get_bios_ebda());

	rio_table_hdr = NULL;
	prev_offset = 0;
	offset = 0x180;
	/*
	 * The next offset is stored in the 1st word.
	 * Only parse up until the offset increases:
	 */
	while (offset > prev_offset) {
		/* The block id is stored in the 2nd word */
		if (*((unsigned short *)(ptr + offset + 2)) == 0x4752){
			/* set the pointer past the offset & block id */
			rio_table_hdr = (struct rio_table_hdr *)(ptr + offset + 4);
			break;
		}
		prev_offset = offset;
		offset = *((unsigned short *)(ptr + offset));
	}
	if (!rio_table_hdr) {
		printk(KERN_DEBUG "Calgary: Unable to locate Rio Grande table "
		       "in EBDA - bailing!\n");
		return -ENODEV;
	}

	ret = build_detail_arrays();
	if (ret) {
		printk(KERN_DEBUG "Calgary: build_detail_arrays ret %d\n", ret);
		return -ENOMEM;
	}

	specified_table_size = determine_tce_table_size((is_kdump_kernel() ?
					saved_max_pfn : max_pfn) * PAGE_SIZE);

	for (bus = 0; bus < MAX_PHB_BUS_NUM; bus++) {
		struct calgary_bus_info *info = &bus_info[bus];
		unsigned short pci_device;
		u32 val;

		val = read_pci_config(bus, 0, 0, 0);
		pci_device = (val & 0xFFFF0000) >> 16;

		if (!is_cal_pci_dev(pci_device))
			continue;

		if (info->translation_disabled)
			continue;

		if (calgary_bus_has_devices(bus, pci_device) ||
		    translate_empty_slots) {
			/*
			 * If it is kdump kernel, find and use tce tables
			 * from first kernel, else allocate tce tables here
			 */
			if (!is_kdump_kernel()) {
				tbl = alloc_tce_table();
				if (!tbl)
					goto cleanup;
				info->tce_space = tbl;
			}
			calgary_found = 1;
		}
	}

	printk(KERN_DEBUG "Calgary: finished detection, Calgary %s\n",
	       calgary_found ? "found" : "not found");

	if (calgary_found) {
		iommu_detected = 1;
		calgary_detected = 1;
		printk(KERN_INFO "PCI-DMA: Calgary IOMMU detected.\n");
		printk(KERN_INFO "PCI-DMA: Calgary TCE table spec is %d\n",
		       specified_table_size);

		x86_init.iommu.iommu_init = calgary_iommu_init;
	}
	return calgary_found;

cleanup:
	for (--bus; bus >= 0; --bus) {
		struct calgary_bus_info *info = &bus_info[bus];

		if (info->tce_space)
			free_tce_table(info->tce_space);
	}
	return -ENOMEM;
}

static int __init calgary_parse_options(char *p)
{
	unsigned int bridge;
	size_t len;
	char* endp;

	while (*p) {
		if (!strncmp(p, "64k", 3))
			specified_table_size = TCE_TABLE_SIZE_64K;
		else if (!strncmp(p, "128k", 4))
			specified_table_size = TCE_TABLE_SIZE_128K;
		else if (!strncmp(p, "256k", 4))
			specified_table_size = TCE_TABLE_SIZE_256K;
		else if (!strncmp(p, "512k", 4))
			specified_table_size = TCE_TABLE_SIZE_512K;
		else if (!strncmp(p, "1M", 2))
			specified_table_size = TCE_TABLE_SIZE_1M;
		else if (!strncmp(p, "2M", 2))
			specified_table_size = TCE_TABLE_SIZE_2M;
		else if (!strncmp(p, "4M", 2))
			specified_table_size = TCE_TABLE_SIZE_4M;
		else if (!strncmp(p, "8M", 2))
			specified_table_size = TCE_TABLE_SIZE_8M;

		len = strlen("translate_empty_slots");
		if (!strncmp(p, "translate_empty_slots", len))
			translate_empty_slots = 1;

		len = strlen("disable");
		if (!strncmp(p, "disable", len)) {
			p += len;
			if (*p == '=')
				++p;
			if (*p == '\0')
				break;
			bridge = simple_strtoul(p, &endp, 0);
			if (p == endp)
				break;

			if (bridge < MAX_PHB_BUS_NUM) {
				printk(KERN_INFO "Calgary: disabling "
				       "translation for PHB %#x\n", bridge);
				bus_info[bridge].translation_disabled = 1;
			}
		}

		p = strpbrk(p, ",");
		if (!p)
			break;

		p++; /* skip ',' */
	}
	return 1;
}
__setup("calgary=", calgary_parse_options);

static void __init calgary_fixup_one_tce_space(struct pci_dev *dev)
{
	struct iommu_table *tbl;
	unsigned int npages;
	int i;

	tbl = pci_iommu(dev->bus);

	for (i = 0; i < 4; i++) {
		struct resource *r = &dev->resource[PCI_BRIDGE_RESOURCES + i];

		/* Don't give out TCEs that map MEM resources */
		if (!(r->flags & IORESOURCE_MEM))
			continue;

		/* 0-based? we reserve the whole 1st MB anyway */
		if (!r->start)
			continue;

		/* cover the whole region */
		npages = resource_size(r) >> PAGE_SHIFT;
		npages++;

		iommu_range_reserve(tbl, r->start, npages);
	}
}

static int __init calgary_fixup_tce_spaces(void)
{
	struct pci_dev *dev = NULL;
	struct calgary_bus_info *info;

	if (no_iommu || swiotlb || !calgary_detected)
		return -ENODEV;

	printk(KERN_DEBUG "Calgary: fixing up tce spaces\n");

	do {
		dev = pci_get_device(PCI_VENDOR_ID_IBM, PCI_ANY_ID, dev);
		if (!dev)
			break;
		if (!is_cal_pci_dev(dev->device))
			continue;

		info = &bus_info[dev->bus->number];
		if (info->translation_disabled)
			continue;

		if (!info->tce_space)
			continue;

		calgary_fixup_one_tce_space(dev);

	} while (1);

	return 0;
}

/*
 * We need to be call after pcibios_assign_resources (fs_initcall level)
 * and before device_initcall.
 */
rootfs_initcall(calgary_fixup_tce_spaces);

IOMMU_INIT_POST(detect_calgary);