Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2147 insertions, 0 deletions

diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c
new file mode 100644
index 000000000..9148ddbf0
--- /dev/null
+++ b/arch/ia64/hp/common/sba_iommu.c
@@ -0,0 +1,2147 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+**  IA64 System Bus Adapter (SBA) I/O MMU manager
+**
+**	(c) Copyright 2002-2005 Alex Williamson
+**	(c) Copyright 2002-2003 Grant Grundler
+**	(c) Copyright 2002-2005 Hewlett-Packard Company
+**
+**	Portions (c) 2000 Grant Grundler (from parisc I/O MMU code)
+**	Portions (c) 1999 Dave S. Miller (from sparc64 I/O MMU code)
+**
+**
+**
+** This module initializes the IOC (I/O Controller) found on HP
+** McKinley machines and their successors.
+**
+*/
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/pci.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/acpi.h>
+#include <linux/efi.h>
+#include <linux/nodemask.h>
+#include <linux/bitops.h>         /* hweight64() */
+#include <linux/crash_dump.h>
+#include <linux/iommu-helper.h>
+#include <linux/dma-map-ops.h>
+#include <linux/prefetch.h>
+#include <linux/swiotlb.h>
+
+#include <asm/delay.h>		/* ia64_get_itc() */
+#include <asm/io.h>
+#include <asm/page.h>		/* PAGE_OFFSET */
+#include <asm/dma.h>
+
+#include <asm/acpi-ext.h>
+
+#define PFX "IOC: "
+
+/*
+** Enabling timing search of the pdir resource map.  Output in /proc.
+** Disabled by default to optimize performance.
+*/
+#undef PDIR_SEARCH_TIMING
+
+/*
+** This option allows cards capable of 64bit DMA to bypass the IOMMU.  If
+** not defined, all DMA will be 32bit and go through the TLB.
+** There's potentially a conflict in the bio merge code with us
+** advertising an iommu, but then bypassing it.  Since I/O MMU bypassing
+** appears to give more performance than bio-level virtual merging, we'll
+** do the former for now.  NOTE: BYPASS_SG also needs to be undef'd to
+** completely restrict DMA to the IOMMU.
+*/
+#define ALLOW_IOV_BYPASS
+
+/*
+** This option specifically allows/disallows bypassing scatterlists with
+** multiple entries.  Coalescing these entries can allow better DMA streaming
+** and in some cases shows better performance than entirely bypassing the
+** IOMMU.  Performance increase on the order of 1-2% sequential output/input
+** using bonnie++ on a RAID0 MD device (sym2 & mpt).
+*/
+#undef ALLOW_IOV_BYPASS_SG
+
+/*
+** If a device prefetches beyond the end of a valid pdir entry, it will cause
+** a hard failure, ie. MCA.  Version 3.0 and later of the zx1 LBA should
+** disconnect on 4k boundaries and prevent such issues.  If the device is
+** particularly aggressive, this option will keep the entire pdir valid such
+** that prefetching will hit a valid address.  This could severely impact
+** error containment, and is therefore off by default.  The page that is
+** used for spill-over is poisoned, so that should help debugging somewhat.
+*/
+#undef FULL_VALID_PDIR
+
+#define ENABLE_MARK_CLEAN
+
+/*
+** The number of debug flags is a clue - this code is fragile.  NOTE: since
+** tightening the use of res_lock the resource bitmap and actual pdir are no
+** longer guaranteed to stay in sync.  The sanity checking code isn't going to
+** like that.
+*/
+#undef DEBUG_SBA_INIT
+#undef DEBUG_SBA_RUN
+#undef DEBUG_SBA_RUN_SG
+#undef DEBUG_SBA_RESOURCE
+#undef ASSERT_PDIR_SANITY
+#undef DEBUG_LARGE_SG_ENTRIES
+#undef DEBUG_BYPASS
+
+#if defined(FULL_VALID_PDIR) && defined(ASSERT_PDIR_SANITY)
+#error FULL_VALID_PDIR and ASSERT_PDIR_SANITY are mutually exclusive
+#endif
+
+#define SBA_INLINE	__inline__
+/* #define SBA_INLINE */
+
+#ifdef DEBUG_SBA_INIT
+#define DBG_INIT(x...)	printk(x)
+#else
+#define DBG_INIT(x...)
+#endif
+
+#ifdef DEBUG_SBA_RUN
+#define DBG_RUN(x...)	printk(x)
+#else
+#define DBG_RUN(x...)
+#endif
+
+#ifdef DEBUG_SBA_RUN_SG
+#define DBG_RUN_SG(x...)	printk(x)
+#else
+#define DBG_RUN_SG(x...)
+#endif
+
+
+#ifdef DEBUG_SBA_RESOURCE
+#define DBG_RES(x...)	printk(x)
+#else
+#define DBG_RES(x...)
+#endif
+
+#ifdef DEBUG_BYPASS
+#define DBG_BYPASS(x...)	printk(x)
+#else
+#define DBG_BYPASS(x...)
+#endif
+
+#ifdef ASSERT_PDIR_SANITY
+#define ASSERT(expr) \
+        if(!(expr)) { \
+                printk( "\n" __FILE__ ":%d: Assertion " #expr " failed!\n",__LINE__); \
+                panic(#expr); \
+        }
+#else
+#define ASSERT(expr)
+#endif
+
+/*
+** The number of pdir entries to "free" before issuing
+** a read to PCOM register to flush out PCOM writes.
+** Interacts with allocation granularity (ie 4 or 8 entries
+** allocated and free'd/purged at a time might make this
+** less interesting).
+*/
+#define DELAYED_RESOURCE_CNT	64
+
+#define PCI_DEVICE_ID_HP_SX2000_IOC	0x12ec
+
+#define ZX1_IOC_ID	((PCI_DEVICE_ID_HP_ZX1_IOC << 16) | PCI_VENDOR_ID_HP)
+#define ZX2_IOC_ID	((PCI_DEVICE_ID_HP_ZX2_IOC << 16) | PCI_VENDOR_ID_HP)
+#define REO_IOC_ID	((PCI_DEVICE_ID_HP_REO_IOC << 16) | PCI_VENDOR_ID_HP)
+#define SX1000_IOC_ID	((PCI_DEVICE_ID_HP_SX1000_IOC << 16) | PCI_VENDOR_ID_HP)
+#define SX2000_IOC_ID	((PCI_DEVICE_ID_HP_SX2000_IOC << 16) | PCI_VENDOR_ID_HP)
+
+#define ZX1_IOC_OFFSET	0x1000	/* ACPI reports SBA, we want IOC */
+
+#define IOC_FUNC_ID	0x000
+#define IOC_FCLASS	0x008	/* function class, bist, header, rev... */
+#define IOC_IBASE	0x300	/* IO TLB */
+#define IOC_IMASK	0x308
+#define IOC_PCOM	0x310
+#define IOC_TCNFG	0x318
+#define IOC_PDIR_BASE	0x320
+
+#define IOC_ROPE0_CFG	0x500
+#define   IOC_ROPE_AO	  0x10	/* Allow "Relaxed Ordering" */
+
+
+/* AGP GART driver looks for this */
+#define ZX1_SBA_IOMMU_COOKIE	0x0000badbadc0ffeeUL
+
+/*
+** The zx1 IOC supports 4/8/16/64KB page sizes (see TCNFG register)
+**
+** Some IOCs (sx1000) can run at the above pages sizes, but are
+** really only supported using the IOC at a 4k page size.
+**
+** iovp_size could only be greater than PAGE_SIZE if we are
+** confident the drivers really only touch the next physical
+** page iff that driver instance owns it.
+*/
+static unsigned long iovp_size;
+static unsigned long iovp_shift;
+static unsigned long iovp_mask;
+
+struct ioc {
+	void __iomem	*ioc_hpa;	/* I/O MMU base address */
+	char		*res_map;	/* resource map, bit == pdir entry */
+	u64		*pdir_base;	/* physical base address */
+	unsigned long	ibase;		/* pdir IOV Space base */
+	unsigned long	imask;		/* pdir IOV Space mask */
+
+	unsigned long	*res_hint;	/* next avail IOVP - circular search */
+	unsigned long	dma_mask;
+	spinlock_t	res_lock;	/* protects the resource bitmap, but must be held when */
+					/* clearing pdir to prevent races with allocations. */
+	unsigned int	res_bitshift;	/* from the RIGHT! */
+	unsigned int	res_size;	/* size of resource map in bytes */
+#ifdef CONFIG_NUMA
+	unsigned int	node;		/* node where this IOC lives */
+#endif
+#if DELAYED_RESOURCE_CNT > 0
+	spinlock_t	saved_lock;	/* may want to try to get this on a separate cacheline */
+					/* than res_lock for bigger systems. */
+	int		saved_cnt;
+	struct sba_dma_pair {
+		dma_addr_t	iova;
+		size_t		size;
+	} saved[DELAYED_RESOURCE_CNT];
+#endif
+
+#ifdef PDIR_SEARCH_TIMING
+#define SBA_SEARCH_SAMPLE	0x100
+	unsigned long avg_search[SBA_SEARCH_SAMPLE];
+	unsigned long avg_idx;	/* current index into avg_search */
+#endif
+
+	/* Stuff we don't need in performance path */
+	struct ioc	*next;		/* list of IOC's in system */
+	acpi_handle	handle;		/* for multiple IOC's */
+	const char 	*name;
+	unsigned int	func_id;
+	unsigned int	rev;		/* HW revision of chip */
+	u32		iov_size;
+	unsigned int	pdir_size;	/* in bytes, determined by IOV Space size */
+	struct pci_dev	*sac_only_dev;
+};
+
+static struct ioc *ioc_list, *ioc_found;
+static int reserve_sba_gart = 1;
+
+static SBA_INLINE void sba_mark_invalid(struct ioc *, dma_addr_t, size_t);
+static SBA_INLINE void sba_free_range(struct ioc *, dma_addr_t, size_t);
+
+#define sba_sg_address(sg)	sg_virt((sg))
+
+#ifdef FULL_VALID_PDIR
+static u64 prefetch_spill_page;
+#endif
+
+#define GET_IOC(dev)	((dev_is_pci(dev))						\
+			 ? ((struct ioc *) PCI_CONTROLLER(to_pci_dev(dev))->iommu) : NULL)
+
+/*
+** DMA_CHUNK_SIZE is used by the SCSI mid-layer to break up
+** (or rather not merge) DMAs into manageable chunks.
+** On parisc, this is more of the software/tuning constraint
+** rather than the HW. I/O MMU allocation algorithms can be
+** faster with smaller sizes (to some degree).
+*/
+#define DMA_CHUNK_SIZE  (BITS_PER_LONG*iovp_size)
+
+#define ROUNDUP(x,y) ((x + ((y)-1)) & ~((y)-1))
+
+/************************************
+** SBA register read and write support
+**
+** BE WARNED: register writes are posted.
+**  (ie follow writes which must reach HW with a read)
+**
+*/
+#define READ_REG(addr)       __raw_readq(addr)
+#define WRITE_REG(val, addr) __raw_writeq(val, addr)
+
+#ifdef DEBUG_SBA_INIT
+
+/**
+ * sba_dump_tlb - debugging only - print IOMMU operating parameters
+ * @hpa: base address of the IOMMU
+ *
+ * Print the size/location of the IO MMU PDIR.
+ */
+static void
+sba_dump_tlb(char *hpa)
+{
+	DBG_INIT("IO TLB at 0x%p\n", (void *)hpa);
+	DBG_INIT("IOC_IBASE    : %016lx\n", READ_REG(hpa+IOC_IBASE));
+	DBG_INIT("IOC_IMASK    : %016lx\n", READ_REG(hpa+IOC_IMASK));
+	DBG_INIT("IOC_TCNFG    : %016lx\n", READ_REG(hpa+IOC_TCNFG));
+	DBG_INIT("IOC_PDIR_BASE: %016lx\n", READ_REG(hpa+IOC_PDIR_BASE));
+	DBG_INIT("\n");
+}
+#endif
+
+
+#ifdef ASSERT_PDIR_SANITY
+
+/**
+ * sba_dump_pdir_entry - debugging only - print one IOMMU PDIR entry
+ * @ioc: IO MMU structure which owns the pdir we are interested in.
+ * @msg: text to print ont the output line.
+ * @pide: pdir index.
+ *
+ * Print one entry of the IO MMU PDIR in human readable form.
+ */
+static void
+sba_dump_pdir_entry(struct ioc *ioc, char *msg, uint pide)
+{
+	/* start printing from lowest pde in rval */
+	u64 *ptr = &ioc->pdir_base[pide  & ~(BITS_PER_LONG - 1)];
+	unsigned long *rptr = (unsigned long *) &ioc->res_map[(pide >>3) & -sizeof(unsigned long)];
+	uint rcnt;
+
+	printk(KERN_DEBUG "SBA: %s rp %p bit %d rval 0x%lx\n",
+		 msg, rptr, pide & (BITS_PER_LONG - 1), *rptr);
+
+	rcnt = 0;
+	while (rcnt < BITS_PER_LONG) {
+		printk(KERN_DEBUG "%s %2d %p %016Lx\n",
+		       (rcnt == (pide & (BITS_PER_LONG - 1)))
+		       ? "    -->" : "       ",
+		       rcnt, ptr, (unsigned long long) *ptr );
+		rcnt++;
+		ptr++;
+	}
+	printk(KERN_DEBUG "%s", msg);
+}
+
+
+/**
+ * sba_check_pdir - debugging only - consistency checker
+ * @ioc: IO MMU structure which owns the pdir we are interested in.
+ * @msg: text to print ont the output line.
+ *
+ * Verify the resource map and pdir state is consistent
+ */
+static int
+sba_check_pdir(struct ioc *ioc, char *msg)
+{
+	u64 *rptr_end = (u64 *) &(ioc->res_map[ioc->res_size]);
+	u64 *rptr = (u64 *) ioc->res_map;	/* resource map ptr */
+	u64 *pptr = ioc->pdir_base;	/* pdir ptr */
+	uint pide = 0;
+
+	while (rptr < rptr_end) {
+		u64 rval;
+		int rcnt; /* number of bits we might check */
+
+		rval = *rptr;
+		rcnt = 64;
+
+		while (rcnt) {
+			/* Get last byte and highest bit from that */
+			u32 pde = ((u32)((*pptr >> (63)) & 0x1));
+			if ((rval & 0x1) ^ pde)
+			{
+				/*
+				** BUMMER!  -- res_map != pdir --
+				** Dump rval and matching pdir entries
+				*/
+				sba_dump_pdir_entry(ioc, msg, pide);
+				return(1);
+			}
+			rcnt--;
+			rval >>= 1;	/* try the next bit */
+			pptr++;
+			pide++;
+		}
+		rptr++;	/* look at next word of res_map */
+	}
+	/* It'd be nice if we always got here :^) */
+	return 0;
+}
+
+
+/**
+ * sba_dump_sg - debugging only - print Scatter-Gather list
+ * @ioc: IO MMU structure which owns the pdir we are interested in.
+ * @startsg: head of the SG list
+ * @nents: number of entries in SG list
+ *
+ * print the SG list so we can verify it's correct by hand.
+ */
+static void
+sba_dump_sg( struct ioc *ioc, struct scatterlist *startsg, int nents)
+{
+	while (nents-- > 0) {
+		printk(KERN_DEBUG " %d : DMA %08lx/%05x CPU %p\n", nents,
+		       startsg->dma_address, startsg->dma_length,
+		       sba_sg_address(startsg));
+		startsg = sg_next(startsg);
+	}
+}
+
+static void
+sba_check_sg( struct ioc *ioc, struct scatterlist *startsg, int nents)
+{
+	struct scatterlist *the_sg = startsg;
+	int the_nents = nents;
+
+	while (the_nents-- > 0) {
+		if (sba_sg_address(the_sg) == 0x0UL)
+			sba_dump_sg(NULL, startsg, nents);
+		the_sg = sg_next(the_sg);
+	}
+}
+
+#endif /* ASSERT_PDIR_SANITY */
+
+
+
+
+/**************************************************************
+*
+*   I/O Pdir Resource Management
+*
+*   Bits set in the resource map are in use.
+*   Each bit can represent a number of pages.
+*   LSbs represent lower addresses (IOVA's).
+*
+***************************************************************/
+#define PAGES_PER_RANGE 1	/* could increase this to 4 or 8 if needed */
+
+/* Convert from IOVP to IOVA and vice versa. */
+#define SBA_IOVA(ioc,iovp,offset) ((ioc->ibase) | (iovp) | (offset))
+#define SBA_IOVP(ioc,iova) ((iova) & ~(ioc->ibase))
+
+#define PDIR_ENTRY_SIZE	sizeof(u64)
+
+#define PDIR_INDEX(iovp)   ((iovp)>>iovp_shift)
+
+#define RESMAP_MASK(n)    ~(~0UL << (n))
+#define RESMAP_IDX_MASK   (sizeof(unsigned long) - 1)
+
+
+/**
+ * For most cases the normal get_order is sufficient, however it limits us
+ * to PAGE_SIZE being the minimum mapping alignment and TC flush granularity.
+ * It only incurs about 1 clock cycle to use this one with the static variable
+ * and makes the code more intuitive.
+ */
+static SBA_INLINE int
+get_iovp_order (unsigned long size)
+{
+	long double d = size - 1;
+	long order;
+
+	order = ia64_getf_exp(d);
+	order = order - iovp_shift - 0xffff + 1;
+	if (order < 0)
+		order = 0;
+	return order;
+}
+
+static unsigned long ptr_to_pide(struct ioc *ioc, unsigned long *res_ptr,
+				 unsigned int bitshiftcnt)
+{
+	return (((unsigned long)res_ptr - (unsigned long)ioc->res_map) << 3)
+		+ bitshiftcnt;
+}
+
+/**
+ * sba_search_bitmap - find free space in IO PDIR resource bitmap
+ * @ioc: IO MMU structure which owns the pdir we are interested in.
+ * @bits_wanted: number of entries we need.
+ * @use_hint: use res_hint to indicate where to start looking
+ *
+ * Find consecutive free bits in resource bitmap.
+ * Each bit represents one entry in the IO Pdir.
+ * Cool perf optimization: search for log2(size) bits at a time.
+ */
+static SBA_INLINE unsigned long
+sba_search_bitmap(struct ioc *ioc, struct device *dev,
+		  unsigned long bits_wanted, int use_hint)
+{
+	unsigned long *res_ptr;
+	unsigned long *res_end = (unsigned long *) &(ioc->res_map[ioc->res_size]);
+	unsigned long flags, pide = ~0UL, tpide;
+	unsigned long boundary_size;
+	unsigned long shift;
+	int ret;
+
+	ASSERT(((unsigned long) ioc->res_hint & (sizeof(unsigned long) - 1UL)) == 0);
+	ASSERT(res_ptr < res_end);
+
+	boundary_size = dma_get_seg_boundary_nr_pages(dev, iovp_shift);
+
+	BUG_ON(ioc->ibase & ~iovp_mask);
+	shift = ioc->ibase >> iovp_shift;
+
+	spin_lock_irqsave(&ioc->res_lock, flags);
+
+	/* Allow caller to force a search through the entire resource space */
+	if (likely(use_hint)) {
+		res_ptr = ioc->res_hint;
+	} else {
+		res_ptr = (ulong *)ioc->res_map;
+		ioc->res_bitshift = 0;
+	}
+
+	/*
+	 * N.B.  REO/Grande defect AR2305 can cause TLB fetch timeouts
+	 * if a TLB entry is purged while in use.  sba_mark_invalid()
+	 * purges IOTLB entries in power-of-two sizes, so we also
+	 * allocate IOVA space in power-of-two sizes.
+	 */
+	bits_wanted = 1UL << get_iovp_order(bits_wanted << iovp_shift);
+
+	if (likely(bits_wanted == 1)) {
+		unsigned int bitshiftcnt;
+		for(; res_ptr < res_end ; res_ptr++) {
+			if (likely(*res_ptr != ~0UL)) {
+				bitshiftcnt = ffz(*res_ptr);
+				*res_ptr |= (1UL << bitshiftcnt);
+				pide = ptr_to_pide(ioc, res_ptr, bitshiftcnt);
+				ioc->res_bitshift = bitshiftcnt + bits_wanted;
+				goto found_it;
+			}
+		}
+		goto not_found;
+
+	}
+	
+	if (likely(bits_wanted <= BITS_PER_LONG/2)) {
+		/*
+		** Search the resource bit map on well-aligned values.
+		** "o" is the alignment.
+		** We need the alignment to invalidate I/O TLB using
+		** SBA HW features in the unmap path.
+		*/
+		unsigned long o = 1 << get_iovp_order(bits_wanted << iovp_shift);
+		uint bitshiftcnt = ROUNDUP(ioc->res_bitshift, o);
+		unsigned long mask, base_mask;
+
+		base_mask = RESMAP_MASK(bits_wanted);
+		mask = base_mask << bitshiftcnt;
+
+		DBG_RES("%s() o %ld %p", __func__, o, res_ptr);
+		for(; res_ptr < res_end ; res_ptr++)
+		{ 
+			DBG_RES("    %p %lx %lx\n", res_ptr, mask, *res_ptr);
+			ASSERT(0 != mask);
+			for (; mask ; mask <<= o, bitshiftcnt += o) {
+				tpide = ptr_to_pide(ioc, res_ptr, bitshiftcnt);
+				ret = iommu_is_span_boundary(tpide, bits_wanted,
+							     shift,
+							     boundary_size);
+				if ((0 == ((*res_ptr) & mask)) && !ret) {
+					*res_ptr |= mask;     /* mark resources busy! */
+					pide = tpide;
+					ioc->res_bitshift = bitshiftcnt + bits_wanted;
+					goto found_it;
+				}
+			}
+
+			bitshiftcnt = 0;
+			mask = base_mask;
+
+		}
+
+	} else {
+		int qwords, bits, i;
+		unsigned long *end;
+
+		qwords = bits_wanted >> 6; /* /64 */
+		bits = bits_wanted - (qwords * BITS_PER_LONG);
+
+		end = res_end - qwords;
+
+		for (; res_ptr < end; res_ptr++) {
+			tpide = ptr_to_pide(ioc, res_ptr, 0);
+			ret = iommu_is_span_boundary(tpide, bits_wanted,
+						     shift, boundary_size);
+			if (ret)
+				goto next_ptr;
+			for (i = 0 ; i < qwords ; i++) {
+				if (res_ptr[i] != 0)
+					goto next_ptr;
+			}
+			if (bits && res_ptr[i] && (__ffs(res_ptr[i]) < bits))
+				continue;
+
+			/* Found it, mark it */
+			for (i = 0 ; i < qwords ; i++)
+				res_ptr[i] = ~0UL;
+			res_ptr[i] |= RESMAP_MASK(bits);
+
+			pide = tpide;
+			res_ptr += qwords;
+			ioc->res_bitshift = bits;
+			goto found_it;
+next_ptr:
+			;
+		}
+	}
+
+not_found:
+	prefetch(ioc->res_map);
+	ioc->res_hint = (unsigned long *) ioc->res_map;
+	ioc->res_bitshift = 0;
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+	return (pide);
+
+found_it:
+	ioc->res_hint = res_ptr;
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+	return (pide);
+}
+
+
+/**
+ * sba_alloc_range - find free bits and mark them in IO PDIR resource bitmap
+ * @ioc: IO MMU structure which owns the pdir we are interested in.
+ * @size: number of bytes to create a mapping for
+ *
+ * Given a size, find consecutive unmarked and then mark those bits in the
+ * resource bit map.
+ */
+static int
+sba_alloc_range(struct ioc *ioc, struct device *dev, size_t size)
+{
+	unsigned int pages_needed = size >> iovp_shift;
+#ifdef PDIR_SEARCH_TIMING
+	unsigned long itc_start;
+#endif
+	unsigned long pide;
+
+	ASSERT(pages_needed);
+	ASSERT(0 == (size & ~iovp_mask));
+
+#ifdef PDIR_SEARCH_TIMING
+	itc_start = ia64_get_itc();
+#endif
+	/*
+	** "seek and ye shall find"...praying never hurts either...
+	*/
+	pide = sba_search_bitmap(ioc, dev, pages_needed, 1);
+	if (unlikely(pide >= (ioc->res_size << 3))) {
+		pide = sba_search_bitmap(ioc, dev, pages_needed, 0);
+		if (unlikely(pide >= (ioc->res_size << 3))) {
+#if DELAYED_RESOURCE_CNT > 0
+			unsigned long flags;
+
+			/*
+			** With delayed resource freeing, we can give this one more shot.  We're
+			** getting close to being in trouble here, so do what we can to make this
+			** one count.
+			*/
+			spin_lock_irqsave(&ioc->saved_lock, flags);
+			if (ioc->saved_cnt > 0) {
+				struct sba_dma_pair *d;
+				int cnt = ioc->saved_cnt;
+
+				d = &(ioc->saved[ioc->saved_cnt - 1]);
+
+				spin_lock(&ioc->res_lock);
+				while (cnt--) {
+					sba_mark_invalid(ioc, d->iova, d->size);
+					sba_free_range(ioc, d->iova, d->size);
+					d--;
+				}
+				ioc->saved_cnt = 0;
+				READ_REG(ioc->ioc_hpa+IOC_PCOM);	/* flush purges */
+				spin_unlock(&ioc->res_lock);
+			}
+			spin_unlock_irqrestore(&ioc->saved_lock, flags);
+
+			pide = sba_search_bitmap(ioc, dev, pages_needed, 0);
+			if (unlikely(pide >= (ioc->res_size << 3))) {
+				printk(KERN_WARNING "%s: I/O MMU @ %p is"
+				       "out of mapping resources, %u %u %lx\n",
+				       __func__, ioc->ioc_hpa, ioc->res_size,
+				       pages_needed, dma_get_seg_boundary(dev));
+				return -1;
+			}
+#else
+			printk(KERN_WARNING "%s: I/O MMU @ %p is"
+			       "out of mapping resources, %u %u %lx\n",
+			       __func__, ioc->ioc_hpa, ioc->res_size,
+			       pages_needed, dma_get_seg_boundary(dev));
+			return -1;
+#endif
+		}
+	}
+
+#ifdef PDIR_SEARCH_TIMING
+	ioc->avg_search[ioc->avg_idx++] = (ia64_get_itc() - itc_start) / pages_needed;
+	ioc->avg_idx &= SBA_SEARCH_SAMPLE - 1;
+#endif
+
+	prefetchw(&(ioc->pdir_base[pide]));
+
+#ifdef ASSERT_PDIR_SANITY
+	/* verify the first enable bit is clear */
+	if(0x00 != ((u8 *) ioc->pdir_base)[pide*PDIR_ENTRY_SIZE + 7]) {
+		sba_dump_pdir_entry(ioc, "sba_search_bitmap() botched it?", pide);
+	}
+#endif
+
+	DBG_RES("%s(%x) %d -> %lx hint %x/%x\n",
+		__func__, size, pages_needed, pide,
+		(uint) ((unsigned long) ioc->res_hint - (unsigned long) ioc->res_map),
+		ioc->res_bitshift );
+
+	return (pide);
+}
+
+
+/**
+ * sba_free_range - unmark bits in IO PDIR resource bitmap
+ * @ioc: IO MMU structure which owns the pdir we are interested in.
+ * @iova: IO virtual address which was previously allocated.
+ * @size: number of bytes to create a mapping for
+ *
+ * clear bits in the ioc's resource map
+ */
+static SBA_INLINE void
+sba_free_range(struct ioc *ioc, dma_addr_t iova, size_t size)
+{
+	unsigned long iovp = SBA_IOVP(ioc, iova);
+	unsigned int pide = PDIR_INDEX(iovp);
+	unsigned int ridx = pide >> 3;	/* convert bit to byte address */
+	unsigned long *res_ptr = (unsigned long *) &((ioc)->res_map[ridx & ~RESMAP_IDX_MASK]);
+	int bits_not_wanted = size >> iovp_shift;
+	unsigned long m;
+
+	/* Round up to power-of-two size: see AR2305 note above */
+	bits_not_wanted = 1UL << get_iovp_order(bits_not_wanted << iovp_shift);
+	for (; bits_not_wanted > 0 ; res_ptr++) {
+		
+		if (unlikely(bits_not_wanted > BITS_PER_LONG)) {
+
+			/* these mappings start 64bit aligned */
+			*res_ptr = 0UL;
+			bits_not_wanted -= BITS_PER_LONG;
+			pide += BITS_PER_LONG;
+
+		} else {
+
+			/* 3-bits "bit" address plus 2 (or 3) bits for "byte" == bit in word */
+			m = RESMAP_MASK(bits_not_wanted) << (pide & (BITS_PER_LONG - 1));
+			bits_not_wanted = 0;
+
+			DBG_RES("%s( ,%x,%x) %x/%lx %x %p %lx\n", __func__, (uint) iova, size,
+			        bits_not_wanted, m, pide, res_ptr, *res_ptr);
+
+			ASSERT(m != 0);
+			ASSERT(bits_not_wanted);
+			ASSERT((*res_ptr & m) == m); /* verify same bits are set */
+			*res_ptr &= ~m;
+		}
+	}
+}
+
+
+/**************************************************************
+*
+*   "Dynamic DMA Mapping" support (aka "Coherent I/O")
+*
+***************************************************************/
+
+/**
+ * sba_io_pdir_entry - fill in one IO PDIR entry
+ * @pdir_ptr:  pointer to IO PDIR entry
+ * @vba: Virtual CPU address of buffer to map
+ *
+ * SBA Mapping Routine
+ *
+ * Given a virtual address (vba, arg1) sba_io_pdir_entry()
+ * loads the I/O PDIR entry pointed to by pdir_ptr (arg0).
+ * Each IO Pdir entry consists of 8 bytes as shown below
+ * (LSB == bit 0):
+ *
+ *  63                    40                                 11    7        0
+ * +-+---------------------+----------------------------------+----+--------+
+ * |V|        U            |            PPN[39:12]            | U  |   FF   |
+ * +-+---------------------+----------------------------------+----+--------+
+ *
+ *  V  == Valid Bit
+ *  U  == Unused
+ * PPN == Physical Page Number
+ *
+ * The physical address fields are filled with the results of virt_to_phys()
+ * on the vba.
+ */
+
+#if 1
+#define sba_io_pdir_entry(pdir_ptr, vba) *pdir_ptr = ((vba & ~0xE000000000000FFFULL)	\
+						      | 0x8000000000000000ULL)
+#else
+void SBA_INLINE
+sba_io_pdir_entry(u64 *pdir_ptr, unsigned long vba)
+{
+	*pdir_ptr = ((vba & ~0xE000000000000FFFULL) | 0x80000000000000FFULL);
+}
+#endif
+
+#ifdef ENABLE_MARK_CLEAN
+/**
+ * Since DMA is i-cache coherent, any (complete) pages that were written via
+ * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
+ * flush them when they get mapped into an executable vm-area.
+ */
+static void
+mark_clean (void *addr, size_t size)
+{
+	unsigned long pg_addr, end;
+
+	pg_addr = PAGE_ALIGN((unsigned long) addr);
+	end = (unsigned long) addr + size;
+	while (pg_addr + PAGE_SIZE <= end) {
+		struct page *page = virt_to_page((void *)pg_addr);
+		set_bit(PG_arch_1, &page->flags);
+		pg_addr += PAGE_SIZE;
+	}
+}
+#endif
+
+/**
+ * sba_mark_invalid - invalidate one or more IO PDIR entries
+ * @ioc: IO MMU structure which owns the pdir we are interested in.
+ * @iova:  IO Virtual Address mapped earlier
+ * @byte_cnt:  number of bytes this mapping covers.
+ *
+ * Marking the IO PDIR entry(ies) as Invalid and invalidate
+ * corresponding IO TLB entry. The PCOM (Purge Command Register)
+ * is to purge stale entries in the IO TLB when unmapping entries.
+ *
+ * The PCOM register supports purging of multiple pages, with a minium
+ * of 1 page and a maximum of 2GB. Hardware requires the address be
+ * aligned to the size of the range being purged. The size of the range
+ * must be a power of 2. The "Cool perf optimization" in the
+ * allocation routine helps keep that true.
+ */
+static SBA_INLINE void
+sba_mark_invalid(struct ioc *ioc, dma_addr_t iova, size_t byte_cnt)
+{
+	u32 iovp = (u32) SBA_IOVP(ioc,iova);
+
+	int off = PDIR_INDEX(iovp);
+
+	/* Must be non-zero and rounded up */
+	ASSERT(byte_cnt > 0);
+	ASSERT(0 == (byte_cnt & ~iovp_mask));
+
+#ifdef ASSERT_PDIR_SANITY
+	/* Assert first pdir entry is set */
+	if (!(ioc->pdir_base[off] >> 60)) {
+		sba_dump_pdir_entry(ioc,"sba_mark_invalid()", PDIR_INDEX(iovp));
+	}
+#endif
+
+	if (byte_cnt <= iovp_size)
+	{
+		ASSERT(off < ioc->pdir_size);
+
+		iovp |= iovp_shift;     /* set "size" field for PCOM */
+
+#ifndef FULL_VALID_PDIR
+		/*
+		** clear I/O PDIR entry "valid" bit
+		** Do NOT clear the rest - save it for debugging.
+		** We should only clear bits that have previously
+		** been enabled.
+		*/
+		ioc->pdir_base[off] &= ~(0x80000000000000FFULL);
+#else
+		/*
+  		** If we want to maintain the PDIR as valid, put in
+		** the spill page so devices prefetching won't
+		** cause a hard fail.
+		*/
+		ioc->pdir_base[off] = (0x80000000000000FFULL | prefetch_spill_page);
+#endif
+	} else {
+		u32 t = get_iovp_order(byte_cnt) + iovp_shift;
+
+		iovp |= t;
+		ASSERT(t <= 31);   /* 2GB! Max value of "size" field */
+
+		do {
+			/* verify this pdir entry is enabled */
+			ASSERT(ioc->pdir_base[off]  >> 63);
+#ifndef FULL_VALID_PDIR
+			/* clear I/O Pdir entry "valid" bit first */
+			ioc->pdir_base[off] &= ~(0x80000000000000FFULL);
+#else
+			ioc->pdir_base[off] = (0x80000000000000FFULL | prefetch_spill_page);
+#endif
+			off++;
+			byte_cnt -= iovp_size;
+		} while (byte_cnt > 0);
+	}
+
+	WRITE_REG(iovp | ioc->ibase, ioc->ioc_hpa+IOC_PCOM);
+}
+
+/**
+ * sba_map_page - map one buffer and return IOVA for DMA
+ * @dev: instance of PCI owned by the driver that's asking.
+ * @page: page to map
+ * @poff: offset into page
+ * @size: number of bytes to map
+ * @dir: dma direction
+ * @attrs: optional dma attributes
+ *
+ * See Documentation/core-api/dma-api-howto.rst
+ */
+static dma_addr_t sba_map_page(struct device *dev, struct page *page,
+			       unsigned long poff, size_t size,
+			       enum dma_data_direction dir,
+			       unsigned long attrs)
+{
+	struct ioc *ioc;
+	void *addr = page_address(page) + poff;
+	dma_addr_t iovp;
+	dma_addr_t offset;
+	u64 *pdir_start;
+	int pide;
+#ifdef ASSERT_PDIR_SANITY
+	unsigned long flags;
+#endif
+#ifdef ALLOW_IOV_BYPASS
+	unsigned long pci_addr = virt_to_phys(addr);
+#endif
+
+#ifdef ALLOW_IOV_BYPASS
+	ASSERT(to_pci_dev(dev)->dma_mask);
+	/*
+ 	** Check if the PCI device can DMA to ptr... if so, just return ptr
+ 	*/
+	if (likely((pci_addr & ~to_pci_dev(dev)->dma_mask) == 0)) {
+		/*
+ 		** Device is bit capable of DMA'ing to the buffer...
+		** just return the PCI address of ptr
+ 		*/
+		DBG_BYPASS("sba_map_page() bypass mask/addr: "
+			   "0x%lx/0x%lx\n",
+		           to_pci_dev(dev)->dma_mask, pci_addr);
+		return pci_addr;
+	}
+#endif
+	ioc = GET_IOC(dev);
+	ASSERT(ioc);
+
+	prefetch(ioc->res_hint);
+
+	ASSERT(size > 0);
+	ASSERT(size <= DMA_CHUNK_SIZE);
+
+	/* save offset bits */
+	offset = ((dma_addr_t) (long) addr) & ~iovp_mask;
+
+	/* round up to nearest iovp_size */
+	size = (size + offset + ~iovp_mask) & iovp_mask;
+
+#ifdef ASSERT_PDIR_SANITY
+	spin_lock_irqsave(&ioc->res_lock, flags);
+	if (sba_check_pdir(ioc,"Check before sba_map_page()"))
+		panic("Sanity check failed");
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif
+
+	pide = sba_alloc_range(ioc, dev, size);
+	if (pide < 0)
+		return DMA_MAPPING_ERROR;
+
+	iovp = (dma_addr_t) pide << iovp_shift;
+
+	DBG_RUN("%s() 0x%p -> 0x%lx\n", __func__, addr, (long) iovp | offset);
+
+	pdir_start = &(ioc->pdir_base[pide]);
+
+	while (size > 0) {
+		ASSERT(((u8 *)pdir_start)[7] == 0); /* verify availability */
+		sba_io_pdir_entry(pdir_start, (unsigned long) addr);
+
+		DBG_RUN("     pdir 0x%p %lx\n", pdir_start, *pdir_start);
+
+		addr += iovp_size;
+		size -= iovp_size;
+		pdir_start++;
+	}
+	/* force pdir update */
+	wmb();
+
+	/* form complete address */
+#ifdef ASSERT_PDIR_SANITY
+	spin_lock_irqsave(&ioc->res_lock, flags);
+	sba_check_pdir(ioc,"Check after sba_map_page()");
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif
+	return SBA_IOVA(ioc, iovp, offset);
+}
+
+#ifdef ENABLE_MARK_CLEAN
+static SBA_INLINE void
+sba_mark_clean(struct ioc *ioc, dma_addr_t iova, size_t size)
+{
+	u32	iovp = (u32) SBA_IOVP(ioc,iova);
+	int	off = PDIR_INDEX(iovp);
+	void	*addr;
+
+	if (size <= iovp_size) {
+		addr = phys_to_virt(ioc->pdir_base[off] &
+		                    ~0xE000000000000FFFULL);
+		mark_clean(addr, size);
+	} else {
+		do {
+			addr = phys_to_virt(ioc->pdir_base[off] &
+			                    ~0xE000000000000FFFULL);
+			mark_clean(addr, min(size, iovp_size));
+			off++;
+			size -= iovp_size;
+		} while (size > 0);
+	}
+}
+#endif
+
+/**
+ * sba_unmap_page - unmap one IOVA and free resources
+ * @dev: instance of PCI owned by the driver that's asking.
+ * @iova:  IOVA of driver buffer previously mapped.
+ * @size:  number of bytes mapped in driver buffer.
+ * @dir:  R/W or both.
+ * @attrs: optional dma attributes
+ *
+ * See Documentation/core-api/dma-api-howto.rst
+ */
+static void sba_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
+			   enum dma_data_direction dir, unsigned long attrs)
+{
+	struct ioc *ioc;
+#if DELAYED_RESOURCE_CNT > 0
+	struct sba_dma_pair *d;
+#endif
+	unsigned long flags;
+	dma_addr_t offset;
+
+	ioc = GET_IOC(dev);
+	ASSERT(ioc);
+
+#ifdef ALLOW_IOV_BYPASS
+	if (likely((iova & ioc->imask) != ioc->ibase)) {
+		/*
+		** Address does not fall w/in IOVA, must be bypassing
+		*/
+		DBG_BYPASS("sba_unmap_page() bypass addr: 0x%lx\n",
+			   iova);
+
+#ifdef ENABLE_MARK_CLEAN
+		if (dir == DMA_FROM_DEVICE) {
+			mark_clean(phys_to_virt(iova), size);
+		}
+#endif
+		return;
+	}
+#endif
+	offset = iova & ~iovp_mask;
+
+	DBG_RUN("%s() iovp 0x%lx/%x\n", __func__, (long) iova, size);
+
+	iova ^= offset;        /* clear offset bits */
+	size += offset;
+	size = ROUNDUP(size, iovp_size);
+
+#ifdef ENABLE_MARK_CLEAN
+	if (dir == DMA_FROM_DEVICE)
+		sba_mark_clean(ioc, iova, size);
+#endif
+
+#if DELAYED_RESOURCE_CNT > 0
+	spin_lock_irqsave(&ioc->saved_lock, flags);
+	d = &(ioc->saved[ioc->saved_cnt]);
+	d->iova = iova;
+	d->size = size;
+	if (unlikely(++(ioc->saved_cnt) >= DELAYED_RESOURCE_CNT)) {
+		int cnt = ioc->saved_cnt;
+		spin_lock(&ioc->res_lock);
+		while (cnt--) {
+			sba_mark_invalid(ioc, d->iova, d->size);
+			sba_free_range(ioc, d->iova, d->size);
+			d--;
+		}
+		ioc->saved_cnt = 0;
+		READ_REG(ioc->ioc_hpa+IOC_PCOM);	/* flush purges */
+		spin_unlock(&ioc->res_lock);
+	}
+	spin_unlock_irqrestore(&ioc->saved_lock, flags);
+#else /* DELAYED_RESOURCE_CNT == 0 */
+	spin_lock_irqsave(&ioc->res_lock, flags);
+	sba_mark_invalid(ioc, iova, size);
+	sba_free_range(ioc, iova, size);
+	READ_REG(ioc->ioc_hpa+IOC_PCOM);	/* flush purges */
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif /* DELAYED_RESOURCE_CNT == 0 */
+}
+
+/**
+ * sba_alloc_coherent - allocate/map shared mem for DMA
+ * @dev: instance of PCI owned by the driver that's asking.
+ * @size:  number of bytes mapped in driver buffer.
+ * @dma_handle:  IOVA of new buffer.
+ *
+ * See Documentation/core-api/dma-api-howto.rst
+ */
+static void *
+sba_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
+		   gfp_t flags, unsigned long attrs)
+{
+	struct page *page;
+	struct ioc *ioc;
+	int node = -1;
+	void *addr;
+
+	ioc = GET_IOC(dev);
+	ASSERT(ioc);
+#ifdef CONFIG_NUMA
+	node = ioc->node;
+#endif
+
+	page = alloc_pages_node(node, flags, get_order(size));
+	if (unlikely(!page))
+		return NULL;
+
+	addr = page_address(page);
+	memset(addr, 0, size);
+	*dma_handle = page_to_phys(page);
+
+#ifdef ALLOW_IOV_BYPASS
+	ASSERT(dev->coherent_dma_mask);
+	/*
+ 	** Check if the PCI device can DMA to ptr... if so, just return ptr
+ 	*/
+	if (likely((*dma_handle & ~dev->coherent_dma_mask) == 0)) {
+		DBG_BYPASS("sba_alloc_coherent() bypass mask/addr: 0x%lx/0x%lx\n",
+		           dev->coherent_dma_mask, *dma_handle);
+
+		return addr;
+	}
+#endif
+
+	/*
+	 * If device can't bypass or bypass is disabled, pass the 32bit fake
+	 * device to map single to get an iova mapping.
+	 */
+	*dma_handle = sba_map_page(&ioc->sac_only_dev->dev, page, 0, size,
+			DMA_BIDIRECTIONAL, 0);
+	if (dma_mapping_error(dev, *dma_handle))
+		return NULL;
+	return addr;
+}
+
+
+/**
+ * sba_free_coherent - free/unmap shared mem for DMA
+ * @dev: instance of PCI owned by the driver that's asking.
+ * @size:  number of bytes mapped in driver buffer.
+ * @vaddr:  virtual address IOVA of "consistent" buffer.
+ * @dma_handler:  IO virtual address of "consistent" buffer.
+ *
+ * See Documentation/core-api/dma-api-howto.rst
+ */
+static void sba_free_coherent(struct device *dev, size_t size, void *vaddr,
+			      dma_addr_t dma_handle, unsigned long attrs)
+{
+	sba_unmap_page(dev, dma_handle, size, 0, 0);
+	free_pages((unsigned long) vaddr, get_order(size));
+}
+
+
+/*
+** Since 0 is a valid pdir_base index value, can't use that
+** to determine if a value is valid or not. Use a flag to indicate
+** the SG list entry contains a valid pdir index.
+*/
+#define PIDE_FLAG 0x1UL
+
+#ifdef DEBUG_LARGE_SG_ENTRIES
+int dump_run_sg = 0;
+#endif
+
+
+/**
+ * sba_fill_pdir - write allocated SG entries into IO PDIR
+ * @ioc: IO MMU structure which owns the pdir we are interested in.
+ * @startsg:  list of IOVA/size pairs
+ * @nents: number of entries in startsg list
+ *
+ * Take preprocessed SG list and write corresponding entries
+ * in the IO PDIR.
+ */
+
+static SBA_INLINE int
+sba_fill_pdir(
+	struct ioc *ioc,
+	struct scatterlist *startsg,
+	int nents)
+{
+	struct scatterlist *dma_sg = startsg;	/* pointer to current DMA */
+	int n_mappings = 0;
+	u64 *pdirp = NULL;
+	unsigned long dma_offset = 0;
+
+	while (nents-- > 0) {
+		int     cnt = startsg->dma_length;
+		startsg->dma_length = 0;
+
+#ifdef DEBUG_LARGE_SG_ENTRIES
+		if (dump_run_sg)
+			printk(" %2d : %08lx/%05x %p\n",
+				nents, startsg->dma_address, cnt,
+				sba_sg_address(startsg));
+#else
+		DBG_RUN_SG(" %d : %08lx/%05x %p\n",
+				nents, startsg->dma_address, cnt,
+				sba_sg_address(startsg));
+#endif
+		/*
+		** Look for the start of a new DMA stream
+		*/
+		if (startsg->dma_address & PIDE_FLAG) {
+			u32 pide = startsg->dma_address & ~PIDE_FLAG;
+			dma_offset = (unsigned long) pide & ~iovp_mask;
+			startsg->dma_address = 0;
+			if (n_mappings)
+				dma_sg = sg_next(dma_sg);
+			dma_sg->dma_address = pide | ioc->ibase;
+			pdirp = &(ioc->pdir_base[pide >> iovp_shift]);
+			n_mappings++;
+		}
+
+		/*
+		** Look for a VCONTIG chunk
+		*/
+		if (cnt) {
+			unsigned long vaddr = (unsigned long) sba_sg_address(startsg);
+			ASSERT(pdirp);
+
+			/* Since multiple Vcontig blocks could make up
+			** one DMA stream, *add* cnt to dma_len.
+			*/
+			dma_sg->dma_length += cnt;
+			cnt += dma_offset;
+			dma_offset=0;	/* only want offset on first chunk */
+			cnt = ROUNDUP(cnt, iovp_size);
+			do {
+				sba_io_pdir_entry(pdirp, vaddr);
+				vaddr += iovp_size;
+				cnt -= iovp_size;
+				pdirp++;
+			} while (cnt > 0);
+		}
+		startsg = sg_next(startsg);
+	}
+	/* force pdir update */
+	wmb();
+
+#ifdef DEBUG_LARGE_SG_ENTRIES
+	dump_run_sg = 0;
+#endif
+	return(n_mappings);
+}
+
+
+/*
+** Two address ranges are DMA contiguous *iff* "end of prev" and
+** "start of next" are both on an IOV page boundary.
+**
+** (shift left is a quick trick to mask off upper bits)
+*/
+#define DMA_CONTIG(__X, __Y) \
+	(((((unsigned long) __X) | ((unsigned long) __Y)) << (BITS_PER_LONG - iovp_shift)) == 0UL)
+
+
+/**
+ * sba_coalesce_chunks - preprocess the SG list
+ * @ioc: IO MMU structure which owns the pdir we are interested in.
+ * @startsg:  list of IOVA/size pairs
+ * @nents: number of entries in startsg list
+ *
+ * First pass is to walk the SG list and determine where the breaks are
+ * in the DMA stream. Allocates PDIR entries but does not fill them.
+ * Returns the number of DMA chunks.
+ *
+ * Doing the fill separate from the coalescing/allocation keeps the
+ * code simpler. Future enhancement could make one pass through
+ * the sglist do both.
+ */
+static SBA_INLINE int
+sba_coalesce_chunks(struct ioc *ioc, struct device *dev,
+	struct scatterlist *startsg,
+	int nents)
+{
+	struct scatterlist *vcontig_sg;    /* VCONTIG chunk head */
+	unsigned long vcontig_len;         /* len of VCONTIG chunk */
+	unsigned long vcontig_end;
+	struct scatterlist *dma_sg;        /* next DMA stream head */
+	unsigned long dma_offset, dma_len; /* start/len of DMA stream */
+	int n_mappings = 0;
+	unsigned int max_seg_size = dma_get_max_seg_size(dev);
+	int idx;
+
+	while (nents > 0) {
+		unsigned long vaddr = (unsigned long) sba_sg_address(startsg);
+
+		/*
+		** Prepare for first/next DMA stream
+		*/
+		dma_sg = vcontig_sg = startsg;
+		dma_len = vcontig_len = vcontig_end = startsg->length;
+		vcontig_end +=  vaddr;
+		dma_offset = vaddr & ~iovp_mask;
+
+		/* PARANOID: clear entries */
+		startsg->dma_address = startsg->dma_length = 0;
+
+		/*
+		** This loop terminates one iteration "early" since
+		** it's always looking one "ahead".
+		*/
+		while (--nents > 0) {
+			unsigned long vaddr;	/* tmp */
+
+			startsg = sg_next(startsg);
+
+			/* PARANOID */
+			startsg->dma_address = startsg->dma_length = 0;
+
+			/* catch brokenness in SCSI layer */
+			ASSERT(startsg->length <= DMA_CHUNK_SIZE);
+
+			/*
+			** First make sure current dma stream won't
+			** exceed DMA_CHUNK_SIZE if we coalesce the
+			** next entry.
+			*/
+			if (((dma_len + dma_offset + startsg->length + ~iovp_mask) & iovp_mask)
+			    > DMA_CHUNK_SIZE)
+				break;
+
+			if (dma_len + startsg->length > max_seg_size)
+				break;
+
+			/*
+			** Then look for virtually contiguous blocks.
+			**
+			** append the next transaction?
+			*/
+			vaddr = (unsigned long) sba_sg_address(startsg);
+			if  (vcontig_end == vaddr)
+			{
+				vcontig_len += startsg->length;
+				vcontig_end += startsg->length;
+				dma_len     += startsg->length;
+				continue;
+			}
+
+#ifdef DEBUG_LARGE_SG_ENTRIES
+			dump_run_sg = (vcontig_len > iovp_size);
+#endif
+
+			/*
+			** Not virtually contiguous.
+			** Terminate prev chunk.
+			** Start a new chunk.
+			**
+			** Once we start a new VCONTIG chunk, dma_offset
+			** can't change. And we need the offset from the first
+			** chunk - not the last one. Ergo Successive chunks
+			** must start on page boundaries and dove tail
+			** with it's predecessor.
+			*/
+			vcontig_sg->dma_length = vcontig_len;
+
+			vcontig_sg = startsg;
+			vcontig_len = startsg->length;
+
+			/*
+			** 3) do the entries end/start on page boundaries?
+			**    Don't update vcontig_end until we've checked.
+			*/
+			if (DMA_CONTIG(vcontig_end, vaddr))
+			{
+				vcontig_end = vcontig_len + vaddr;
+				dma_len += vcontig_len;
+				continue;
+			} else {
+				break;
+			}
+		}
+
+		/*
+		** End of DMA Stream
+		** Terminate last VCONTIG block.
+		** Allocate space for DMA stream.
+		*/
+		vcontig_sg->dma_length = vcontig_len;
+		dma_len = (dma_len + dma_offset + ~iovp_mask) & iovp_mask;
+		ASSERT(dma_len <= DMA_CHUNK_SIZE);
+		idx = sba_alloc_range(ioc, dev, dma_len);
+		if (idx < 0) {
+			dma_sg->dma_length = 0;
+			return -1;
+		}
+		dma_sg->dma_address = (dma_addr_t)(PIDE_FLAG | (idx << iovp_shift)
+						   | dma_offset);
+		n_mappings++;
+	}
+
+	return n_mappings;
+}
+
+static void sba_unmap_sg_attrs(struct device *dev, struct scatterlist *sglist,
+			       int nents, enum dma_data_direction dir,
+			       unsigned long attrs);
+/**
+ * sba_map_sg - map Scatter/Gather list
+ * @dev: instance of PCI owned by the driver that's asking.
+ * @sglist:  array of buffer/length pairs
+ * @nents:  number of entries in list
+ * @dir:  R/W or both.
+ * @attrs: optional dma attributes
+ *
+ * See Documentation/core-api/dma-api-howto.rst
+ */
+static int sba_map_sg_attrs(struct device *dev, struct scatterlist *sglist,
+			    int nents, enum dma_data_direction dir,
+			    unsigned long attrs)
+{
+	struct ioc *ioc;
+	int coalesced, filled = 0;
+#ifdef ASSERT_PDIR_SANITY
+	unsigned long flags;
+#endif
+#ifdef ALLOW_IOV_BYPASS_SG
+	struct scatterlist *sg;
+#endif
+
+	DBG_RUN_SG("%s() START %d entries\n", __func__, nents);
+	ioc = GET_IOC(dev);
+	ASSERT(ioc);
+
+#ifdef ALLOW_IOV_BYPASS_SG
+	ASSERT(to_pci_dev(dev)->dma_mask);
+	if (likely((ioc->dma_mask & ~to_pci_dev(dev)->dma_mask) == 0)) {
+		for_each_sg(sglist, sg, nents, filled) {
+			sg->dma_length = sg->length;
+			sg->dma_address = virt_to_phys(sba_sg_address(sg));
+		}
+		return filled;
+	}
+#endif
+	/* Fast path single entry scatterlists. */
+	if (nents == 1) {
+		sglist->dma_length = sglist->length;
+		sglist->dma_address = sba_map_page(dev, sg_page(sglist),
+				sglist->offset, sglist->length, dir, attrs);
+		if (dma_mapping_error(dev, sglist->dma_address))
+			return 0;
+		return 1;
+	}
+
+#ifdef ASSERT_PDIR_SANITY
+	spin_lock_irqsave(&ioc->res_lock, flags);
+	if (sba_check_pdir(ioc,"Check before sba_map_sg_attrs()"))
+	{
+		sba_dump_sg(ioc, sglist, nents);
+		panic("Check before sba_map_sg_attrs()");
+	}
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif
+
+	prefetch(ioc->res_hint);
+
+	/*
+	** First coalesce the chunks and allocate I/O pdir space
+	**
+	** If this is one DMA stream, we can properly map using the
+	** correct virtual address associated with each DMA page.
+	** w/o this association, we wouldn't have coherent DMA!
+	** Access to the virtual address is what forces a two pass algorithm.
+	*/
+	coalesced = sba_coalesce_chunks(ioc, dev, sglist, nents);
+	if (coalesced < 0) {
+		sba_unmap_sg_attrs(dev, sglist, nents, dir, attrs);
+		return 0;
+	}
+
+	/*
+	** Program the I/O Pdir
+	**
+	** map the virtual addresses to the I/O Pdir
+	** o dma_address will contain the pdir index
+	** o dma_len will contain the number of bytes to map
+	** o address contains the virtual address.
+	*/
+	filled = sba_fill_pdir(ioc, sglist, nents);
+
+#ifdef ASSERT_PDIR_SANITY
+	spin_lock_irqsave(&ioc->res_lock, flags);
+	if (sba_check_pdir(ioc,"Check after sba_map_sg_attrs()"))
+	{
+		sba_dump_sg(ioc, sglist, nents);
+		panic("Check after sba_map_sg_attrs()\n");
+	}
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif
+
+	ASSERT(coalesced == filled);
+	DBG_RUN_SG("%s() DONE %d mappings\n", __func__, filled);
+
+	return filled;
+}
+
+/**
+ * sba_unmap_sg_attrs - unmap Scatter/Gather list
+ * @dev: instance of PCI owned by the driver that's asking.
+ * @sglist:  array of buffer/length pairs
+ * @nents:  number of entries in list
+ * @dir:  R/W or both.
+ * @attrs: optional dma attributes
+ *
+ * See Documentation/core-api/dma-api-howto.rst
+ */
+static void sba_unmap_sg_attrs(struct device *dev, struct scatterlist *sglist,
+			       int nents, enum dma_data_direction dir,
+			       unsigned long attrs)
+{
+#ifdef ASSERT_PDIR_SANITY
+	struct ioc *ioc;
+	unsigned long flags;
+#endif
+
+	DBG_RUN_SG("%s() START %d entries,  %p,%x\n",
+		   __func__, nents, sba_sg_address(sglist), sglist->length);
+
+#ifdef ASSERT_PDIR_SANITY
+	ioc = GET_IOC(dev);
+	ASSERT(ioc);
+
+	spin_lock_irqsave(&ioc->res_lock, flags);
+	sba_check_pdir(ioc,"Check before sba_unmap_sg_attrs()");
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif
+
+	while (nents && sglist->dma_length) {
+
+		sba_unmap_page(dev, sglist->dma_address, sglist->dma_length,
+			       dir, attrs);
+		sglist = sg_next(sglist);
+		nents--;
+	}
+
+	DBG_RUN_SG("%s() DONE (nents %d)\n", __func__,  nents);
+
+#ifdef ASSERT_PDIR_SANITY
+	spin_lock_irqsave(&ioc->res_lock, flags);
+	sba_check_pdir(ioc,"Check after sba_unmap_sg_attrs()");
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif
+
+}
+
+/**************************************************************
+*
+*   Initialization and claim
+*
+***************************************************************/
+
+static void
+ioc_iova_init(struct ioc *ioc)
+{
+	int tcnfg;
+	int agp_found = 0;
+	struct pci_dev *device = NULL;
+#ifdef FULL_VALID_PDIR
+	unsigned long index;
+#endif
+
+	/*
+	** Firmware programs the base and size of a "safe IOVA space"
+	** (one that doesn't overlap memory or LMMIO space) in the
+	** IBASE and IMASK registers.
+	*/
+	ioc->ibase = READ_REG(ioc->ioc_hpa + IOC_IBASE) & ~0x1UL;
+	ioc->imask = READ_REG(ioc->ioc_hpa + IOC_IMASK) | 0xFFFFFFFF00000000UL;
+
+	ioc->iov_size = ~ioc->imask + 1;
+
+	DBG_INIT("%s() hpa %p IOV base 0x%lx mask 0x%lx (%dMB)\n",
+		__func__, ioc->ioc_hpa, ioc->ibase, ioc->imask,
+		ioc->iov_size >> 20);
+
+	switch (iovp_size) {
+		case  4*1024: tcnfg = 0; break;
+		case  8*1024: tcnfg = 1; break;
+		case 16*1024: tcnfg = 2; break;
+		case 64*1024: tcnfg = 3; break;
+		default:
+			panic(PFX "Unsupported IOTLB page size %ldK",
+				iovp_size >> 10);
+			break;
+	}
+	WRITE_REG(tcnfg, ioc->ioc_hpa + IOC_TCNFG);
+
+	ioc->pdir_size = (ioc->iov_size / iovp_size) * PDIR_ENTRY_SIZE;
+	ioc->pdir_base = (void *) __get_free_pages(GFP_KERNEL,
+						   get_order(ioc->pdir_size));
+	if (!ioc->pdir_base)
+		panic(PFX "Couldn't allocate I/O Page Table\n");
+
+	memset(ioc->pdir_base, 0, ioc->pdir_size);
+
+	DBG_INIT("%s() IOV page size %ldK pdir %p size %x\n", __func__,
+		iovp_size >> 10, ioc->pdir_base, ioc->pdir_size);
+
+	ASSERT(ALIGN((unsigned long) ioc->pdir_base, 4*1024) == (unsigned long) ioc->pdir_base);
+	WRITE_REG(virt_to_phys(ioc->pdir_base), ioc->ioc_hpa + IOC_PDIR_BASE);
+
+	/*
+	** If an AGP device is present, only use half of the IOV space
+	** for PCI DMA.  Unfortunately we can't know ahead of time
+	** whether GART support will actually be used, for now we
+	** can just key on an AGP device found in the system.
+	** We program the next pdir index after we stop w/ a key for
+	** the GART code to handshake on.
+	*/
+	for_each_pci_dev(device)	
+		agp_found |= pci_find_capability(device, PCI_CAP_ID_AGP);
+
+	if (agp_found && reserve_sba_gart) {
+		printk(KERN_INFO PFX "reserving %dMb of IOVA space at 0x%lx for agpgart\n",
+		      ioc->iov_size/2 >> 20, ioc->ibase + ioc->iov_size/2);
+		ioc->pdir_size /= 2;
+		((u64 *)ioc->pdir_base)[PDIR_INDEX(ioc->iov_size/2)] = ZX1_SBA_IOMMU_COOKIE;
+	}
+#ifdef FULL_VALID_PDIR
+	/*
+  	** Check to see if the spill page has been allocated, we don't need more than
+	** one across multiple SBAs.
+	*/
+	if (!prefetch_spill_page) {
+		char *spill_poison = "SBAIOMMU POISON";
+		int poison_size = 16;
+		void *poison_addr, *addr;
+
+		addr = (void *)__get_free_pages(GFP_KERNEL, get_order(iovp_size));
+		if (!addr)
+			panic(PFX "Couldn't allocate PDIR spill page\n");
+
+		poison_addr = addr;
+		for ( ; (u64) poison_addr < addr + iovp_size; poison_addr += poison_size)
+			memcpy(poison_addr, spill_poison, poison_size);
+
+		prefetch_spill_page = virt_to_phys(addr);
+
+		DBG_INIT("%s() prefetch spill addr: 0x%lx\n", __func__, prefetch_spill_page);
+	}
+	/*
+  	** Set all the PDIR entries valid w/ the spill page as the target
+	*/
+	for (index = 0 ; index < (ioc->pdir_size / PDIR_ENTRY_SIZE) ; index++)
+		((u64 *)ioc->pdir_base)[index] = (0x80000000000000FF | prefetch_spill_page);
+#endif
+
+	/* Clear I/O TLB of any possible entries */
+	WRITE_REG(ioc->ibase | (get_iovp_order(ioc->iov_size) + iovp_shift), ioc->ioc_hpa + IOC_PCOM);
+	READ_REG(ioc->ioc_hpa + IOC_PCOM);
+
+	/* Enable IOVA translation */
+	WRITE_REG(ioc->ibase | 1, ioc->ioc_hpa + IOC_IBASE);
+	READ_REG(ioc->ioc_hpa + IOC_IBASE);
+}
+
+static void __init
+ioc_resource_init(struct ioc *ioc)
+{
+	spin_lock_init(&ioc->res_lock);
+#if DELAYED_RESOURCE_CNT > 0
+	spin_lock_init(&ioc->saved_lock);
+#endif
+
+	/* resource map size dictated by pdir_size */
+	ioc->res_size = ioc->pdir_size / PDIR_ENTRY_SIZE; /* entries */
+	ioc->res_size >>= 3;  /* convert bit count to byte count */
+	DBG_INIT("%s() res_size 0x%x\n", __func__, ioc->res_size);
+
+	ioc->res_map = (char *) __get_free_pages(GFP_KERNEL,
+						 get_order(ioc->res_size));
+	if (!ioc->res_map)
+		panic(PFX "Couldn't allocate resource map\n");
+
+	memset(ioc->res_map, 0, ioc->res_size);
+	/* next available IOVP - circular search */
+	ioc->res_hint = (unsigned long *) ioc->res_map;
+
+#ifdef ASSERT_PDIR_SANITY
+	/* Mark first bit busy - ie no IOVA 0 */
+	ioc->res_map[0] = 0x1;
+	ioc->pdir_base[0] = 0x8000000000000000ULL | ZX1_SBA_IOMMU_COOKIE;
+#endif
+#ifdef FULL_VALID_PDIR
+	/* Mark the last resource used so we don't prefetch beyond IOVA space */
+	ioc->res_map[ioc->res_size - 1] |= 0x80UL; /* res_map is chars */
+	ioc->pdir_base[(ioc->pdir_size / PDIR_ENTRY_SIZE) - 1] = (0x80000000000000FF
+							      | prefetch_spill_page);
+#endif
+
+	DBG_INIT("%s() res_map %x %p\n", __func__,
+		 ioc->res_size, (void *) ioc->res_map);
+}
+
+static void __init
+ioc_sac_init(struct ioc *ioc)
+{
+	struct pci_dev *sac = NULL;
+	struct pci_controller *controller = NULL;
+
+	/*
+	 * pci_alloc_coherent() must return a DMA address which is
+	 * SAC (single address cycle) addressable, so allocate a
+	 * pseudo-device to enforce that.
+	 */
+	sac = kzalloc(sizeof(*sac), GFP_KERNEL);
+	if (!sac)
+		panic(PFX "Couldn't allocate struct pci_dev");
+
+	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
+	if (!controller)
+		panic(PFX "Couldn't allocate struct pci_controller");
+
+	controller->iommu = ioc;
+	sac->sysdata = controller;
+	sac->dma_mask = 0xFFFFFFFFUL;
+	sac->dev.bus = &pci_bus_type;
+	ioc->sac_only_dev = sac;
+}
+
+static void __init
+ioc_zx1_init(struct ioc *ioc)
+{
+	unsigned long rope_config;
+	unsigned int i;
+
+	if (ioc->rev < 0x20)
+		panic(PFX "IOC 2.0 or later required for IOMMU support\n");
+
+	/* 38 bit memory controller + extra bit for range displaced by MMIO */
+	ioc->dma_mask = (0x1UL << 39) - 1;
+
+	/*
+	** Clear ROPE(N)_CONFIG AO bit.
+	** Disables "NT Ordering" (~= !"Relaxed Ordering")
+	** Overrides bit 1 in DMA Hint Sets.
+	** Improves netperf UDP_STREAM by ~10% for tg3 on bcm5701.
+	*/
+	for (i=0; i<(8*8); i+=8) {
+		rope_config = READ_REG(ioc->ioc_hpa + IOC_ROPE0_CFG + i);
+		rope_config &= ~IOC_ROPE_AO;
+		WRITE_REG(rope_config, ioc->ioc_hpa + IOC_ROPE0_CFG + i);
+	}
+}
+
+typedef void (initfunc)(struct ioc *);
+
+struct ioc_iommu {
+	u32 func_id;
+	char *name;
+	initfunc *init;
+};
+
+static struct ioc_iommu ioc_iommu_info[] __initdata = {
+	{ ZX1_IOC_ID, "zx1", ioc_zx1_init },
+	{ ZX2_IOC_ID, "zx2", NULL },
+	{ SX1000_IOC_ID, "sx1000", NULL },
+	{ SX2000_IOC_ID, "sx2000", NULL },
+};
+
+static void __init ioc_init(unsigned long hpa, struct ioc *ioc)
+{
+	struct ioc_iommu *info;
+
+	ioc->next = ioc_list;
+	ioc_list = ioc;
+
+	ioc->ioc_hpa = ioremap(hpa, 0x1000);
+
+	ioc->func_id = READ_REG(ioc->ioc_hpa + IOC_FUNC_ID);
+	ioc->rev = READ_REG(ioc->ioc_hpa + IOC_FCLASS) & 0xFFUL;
+	ioc->dma_mask = 0xFFFFFFFFFFFFFFFFUL;	/* conservative */
+
+	for (info = ioc_iommu_info; info < ioc_iommu_info + ARRAY_SIZE(ioc_iommu_info); info++) {
+		if (ioc->func_id == info->func_id) {
+			ioc->name = info->name;
+			if (info->init)
+				(info->init)(ioc);
+		}
+	}
+
+	iovp_size = (1 << iovp_shift);
+	iovp_mask = ~(iovp_size - 1);
+
+	DBG_INIT("%s: PAGE_SIZE %ldK, iovp_size %ldK\n", __func__,
+		PAGE_SIZE >> 10, iovp_size >> 10);
+
+	if (!ioc->name) {
+		ioc->name = kmalloc(24, GFP_KERNEL);
+		if (ioc->name)
+			sprintf((char *) ioc->name, "Unknown (%04x:%04x)",
+				ioc->func_id & 0xFFFF, (ioc->func_id >> 16) & 0xFFFF);
+		else
+			ioc->name = "Unknown";
+	}
+
+	ioc_iova_init(ioc);
+	ioc_resource_init(ioc);
+	ioc_sac_init(ioc);
+
+	printk(KERN_INFO PFX
+		"%s %d.%d HPA 0x%lx IOVA space %dMb at 0x%lx\n",
+		ioc->name, (ioc->rev >> 4) & 0xF, ioc->rev & 0xF,
+		hpa, ioc->iov_size >> 20, ioc->ibase);
+}
+
+
+
+/**************************************************************************
+**
+**   SBA initialization code (HW and SW)
+**
+**   o identify SBA chip itself
+**   o FIXME: initialize DMA hints for reasonable defaults
+**
+**************************************************************************/
+
+#ifdef CONFIG_PROC_FS
+static void *
+ioc_start(struct seq_file *s, loff_t *pos)
+{
+	struct ioc *ioc;
+	loff_t n = *pos;
+
+	for (ioc = ioc_list; ioc; ioc = ioc->next)
+		if (!n--)
+			return ioc;
+
+	return NULL;
+}
+
+static void *
+ioc_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	struct ioc *ioc = v;
+
+	++*pos;
+	return ioc->next;
+}
+
+static void
+ioc_stop(struct seq_file *s, void *v)
+{
+}
+
+static int
+ioc_show(struct seq_file *s, void *v)
+{
+	struct ioc *ioc = v;
+	unsigned long *res_ptr = (unsigned long *)ioc->res_map;
+	int i, used = 0;
+
+	seq_printf(s, "Hewlett Packard %s IOC rev %d.%d\n",
+		ioc->name, ((ioc->rev >> 4) & 0xF), (ioc->rev & 0xF));
+#ifdef CONFIG_NUMA
+	if (ioc->node != NUMA_NO_NODE)
+		seq_printf(s, "NUMA node       : %d\n", ioc->node);
+#endif
+	seq_printf(s, "IOVA size       : %ld MB\n", ((ioc->pdir_size >> 3) * iovp_size)/(1024*1024));
+	seq_printf(s, "IOVA page size  : %ld kb\n", iovp_size/1024);
+
+	for (i = 0; i < (ioc->res_size / sizeof(unsigned long)); ++i, ++res_ptr)
+		used += hweight64(*res_ptr);
+
+	seq_printf(s, "PDIR size       : %d entries\n", ioc->pdir_size >> 3);
+	seq_printf(s, "PDIR used       : %d entries\n", used);
+
+#ifdef PDIR_SEARCH_TIMING
+	{
+		unsigned long i = 0, avg = 0, min, max;
+		min = max = ioc->avg_search[0];
+		for (i = 0; i < SBA_SEARCH_SAMPLE; i++) {
+			avg += ioc->avg_search[i];
+			if (ioc->avg_search[i] > max) max = ioc->avg_search[i];
+			if (ioc->avg_search[i] < min) min = ioc->avg_search[i];
+		}
+		avg /= SBA_SEARCH_SAMPLE;
+		seq_printf(s, "Bitmap search   : %ld/%ld/%ld (min/avg/max CPU Cycles/IOVA page)\n",
+		           min, avg, max);
+	}
+#endif
+#ifndef ALLOW_IOV_BYPASS
+	 seq_printf(s, "IOVA bypass disabled\n");
+#endif
+	return 0;
+}
+
+static const struct seq_operations ioc_seq_ops = {
+	.start = ioc_start,
+	.next  = ioc_next,
+	.stop  = ioc_stop,
+	.show  = ioc_show
+};
+
+static void __init
+ioc_proc_init(void)
+{
+	struct proc_dir_entry *dir;
+
+	dir = proc_mkdir("bus/mckinley", NULL);
+	if (!dir)
+		return;
+
+	proc_create_seq(ioc_list->name, 0, dir, &ioc_seq_ops);
+}
+#endif
+
+static void
+sba_connect_bus(struct pci_bus *bus)
+{
+	acpi_handle handle, parent;
+	acpi_status status;
+	struct ioc *ioc;
+
+	if (!PCI_CONTROLLER(bus))
+		panic(PFX "no sysdata on bus %d!\n", bus->number);
+
+	if (PCI_CONTROLLER(bus)->iommu)
+		return;
+
+	handle = acpi_device_handle(PCI_CONTROLLER(bus)->companion);
+	if (!handle)
+		return;
+
+	/*
+	 * The IOC scope encloses PCI root bridges in the ACPI
+	 * namespace, so work our way out until we find an IOC we
+	 * claimed previously.
+	 */
+	do {
+		for (ioc = ioc_list; ioc; ioc = ioc->next)
+			if (ioc->handle == handle) {
+				PCI_CONTROLLER(bus)->iommu = ioc;
+				return;
+			}
+
+		status = acpi_get_parent(handle, &parent);
+		handle = parent;
+	} while (ACPI_SUCCESS(status));
+
+	printk(KERN_WARNING "No IOC for PCI Bus %04x:%02x in ACPI\n", pci_domain_nr(bus), bus->number);
+}
+
+static void __init
+sba_map_ioc_to_node(struct ioc *ioc, acpi_handle handle)
+{
+#ifdef CONFIG_NUMA
+	unsigned int node;
+
+	node = acpi_get_node(handle);
+	if (node != NUMA_NO_NODE && !node_online(node))
+		node = NUMA_NO_NODE;
+
+	ioc->node = node;
+#endif
+}
+
+static void __init acpi_sba_ioc_add(struct ioc *ioc)
+{
+	acpi_handle handle = ioc->handle;
+	acpi_status status;
+	u64 hpa, length;
+	struct acpi_device_info *adi;
+
+	ioc_found = ioc->next;
+	status = hp_acpi_csr_space(handle, &hpa, &length);
+	if (ACPI_FAILURE(status))
+		goto err;
+
+	status = acpi_get_object_info(handle, &adi);
+	if (ACPI_FAILURE(status))
+		goto err;
+
+	/*
+	 * For HWP0001, only SBA appears in ACPI namespace.  It encloses the PCI
+	 * root bridges, and its CSR space includes the IOC function.
+	 */
+	if (strncmp("HWP0001", adi->hardware_id.string, 7) == 0) {
+		hpa += ZX1_IOC_OFFSET;
+		/* zx1 based systems default to kernel page size iommu pages */
+		if (!iovp_shift)
+			iovp_shift = min(PAGE_SHIFT, 16);
+	}
+	kfree(adi);
+
+	/*
+	 * default anything not caught above or specified on cmdline to 4k
+	 * iommu page size
+	 */
+	if (!iovp_shift)
+		iovp_shift = 12;
+
+	ioc_init(hpa, ioc);
+	/* setup NUMA node association */
+	sba_map_ioc_to_node(ioc, handle);
+	return;
+
+ err:
+	kfree(ioc);
+}
+
+static const struct acpi_device_id hp_ioc_iommu_device_ids[] = {
+	{"HWP0001", 0},
+	{"HWP0004", 0},
+	{"", 0},
+};
+
+static int acpi_sba_ioc_attach(struct acpi_device *device,
+			       const struct acpi_device_id *not_used)
+{
+	struct ioc *ioc;
+
+	ioc = kzalloc(sizeof(*ioc), GFP_KERNEL);
+	if (!ioc)
+		return -ENOMEM;
+
+	ioc->next = ioc_found;
+	ioc_found = ioc;
+	ioc->handle = device->handle;
+	return 1;
+}
+
+
+static struct acpi_scan_handler acpi_sba_ioc_handler = {
+	.ids	= hp_ioc_iommu_device_ids,
+	.attach	= acpi_sba_ioc_attach,
+};
+
+static int __init acpi_sba_ioc_init_acpi(void)
+{
+	return acpi_scan_add_handler(&acpi_sba_ioc_handler);
+}
+/* This has to run before acpi_scan_init(). */
+arch_initcall(acpi_sba_ioc_init_acpi);
+
+static int sba_dma_supported (struct device *dev, u64 mask)
+{
+	/* make sure it's at least 32bit capable */
+	return ((mask & 0xFFFFFFFFUL) == 0xFFFFFFFFUL);
+}
+
+static const struct dma_map_ops sba_dma_ops = {
+	.alloc			= sba_alloc_coherent,
+	.free			= sba_free_coherent,
+	.map_page		= sba_map_page,
+	.unmap_page		= sba_unmap_page,
+	.map_sg			= sba_map_sg_attrs,
+	.unmap_sg		= sba_unmap_sg_attrs,
+	.dma_supported		= sba_dma_supported,
+	.mmap			= dma_common_mmap,
+	.get_sgtable		= dma_common_get_sgtable,
+	.alloc_pages		= dma_common_alloc_pages,
+	.free_pages		= dma_common_free_pages,
+};
+
+static int __init
+sba_init(void)
+{
+	/*
+	 * If we are booting a kdump kernel, the sba_iommu will cause devices
+	 * that were not shutdown properly to MCA as soon as they are turned
+	 * back on.  Our only option for a successful kdump kernel boot is to
+	 * use swiotlb.
+	 */
+	if (is_kdump_kernel())
+		return 0;
+
+	/*
+	 * ioc_found should be populated by the acpi_sba_ioc_handler's .attach()
+	 * routine, but that only happens if acpi_scan_init() has already run.
+	 */
+	while (ioc_found)
+		acpi_sba_ioc_add(ioc_found);
+
+	if (!ioc_list)
+		return 0;
+
+	{
+		struct pci_bus *b = NULL;
+		while ((b = pci_find_next_bus(b)) != NULL)
+			sba_connect_bus(b);
+	}
+
+	/* no need for swiotlb with the iommu */
+	swiotlb_exit();
+	dma_ops = &sba_dma_ops;
+
+#ifdef CONFIG_PROC_FS
+	ioc_proc_init();
+#endif
+	return 0;
+}
+
+subsys_initcall(sba_init); /* must be initialized after ACPI etc., but before any drivers... */
+
+static int __init
+nosbagart(char *str)
+{
+	reserve_sba_gart = 0;
+	return 1;
+}
+
+__setup("nosbagart", nosbagart);
+
+static int __init
+sba_page_override(char *str)
+{
+	unsigned long page_size;
+
+	page_size = memparse(str, &str);
+	switch (page_size) {
+		case 4096:
+		case 8192:
+		case 16384:
+		case 65536:
+			iovp_shift = ffs(page_size) - 1;
+			break;
+		default:
+			printk("%s: unknown/unsupported iommu page size %ld\n",
+			       __func__, page_size);
+	}
+
+	return 1;
+}
+
+__setup("sbapagesize=",sba_page_override);