patch-2.4.20 linux-2.4.20/arch/ia64/hp/common/sba_iommu.c

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diff -urN linux-2.4.19/arch/ia64/hp/common/sba_iommu.c linux-2.4.20/arch/ia64/hp/common/sba_iommu.c
@@ -0,0 +1,1867 @@
+/*
+**  IA64 System Bus Adapter (SBA) I/O MMU manager
+**
+**	(c) Copyright 2002 Alex Williamson
+**	(c) Copyright 2002 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 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 module initializes the IOC (I/O Controller) found on HP
+** McKinley machines and their successors.
+**
+*/
+
+#include <linux/config.h>
+#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/acpi.h>
+#include <linux/efi.h>
+
+#include <asm/delay.h>		/* ia64_get_itc() */
+#include <asm/io.h>
+#include <asm/page.h>		/* PAGE_OFFSET */
+
+
+#define PFX "IOC: "
+
+#define ALLOW_IOV_BYPASS
+#define ENABLE_MARK_CLEAN
+/*
+** The number of debug flags is a clue - this code is fragile.
+*/
+#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
+
+#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 issueing
+** 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	16
+
+#define DEFAULT_DMA_HINT_REG	0
+
+#define ZX1_IOC_ID	((PCI_DEVICE_ID_HP_ZX1_IOC << 16) | PCI_VENDOR_ID_HP)
+#define REO_IOC_ID	((PCI_DEVICE_ID_HP_REO_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
+
+/* AGP GART driver looks for this */
+#define ZX1_SBA_IOMMU_COOKIE	0x0000badbadc0ffeeUL
+
+/*
+** IOC supports 4/8/16/64KB page sizes (see TCNFG register)
+** It's safer (avoid memory corruption) to keep DMA page mappings
+** equivalently sized to VM PAGE_SIZE.
+**
+** We really can't avoid generating a new mapping for each
+** page since the Virtual Coherence Index has to be generated
+** and updated for each page.
+**
+** 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.
+*/
+#define IOVP_SIZE	PAGE_SIZE
+#define IOVP_SHIFT	PAGE_SHIFT
+#define IOVP_MASK	PAGE_MASK
+
+struct ioc {
+	void		*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 */
+	spinlock_t	res_lock;
+	unsigned long	hint_mask_pdir;	/* bits used for DMA hints */
+	unsigned int	res_bitshift;	/* from the RIGHT! */
+	unsigned int	res_size;	/* size of resource map in bytes */
+	unsigned int	hint_shift_pdir;
+	unsigned long	dma_mask;
+#if DELAYED_RESOURCE_CNT > 0
+	int saved_cnt;
+	struct sba_dma_pair {
+		dma_addr_t	iova;
+		size_t		size;
+	} saved[DELAYED_RESOURCE_CNT];
+#endif
+
+#ifdef CONFIG_PROC_FS
+#define SBA_SEARCH_SAMPLE	0x100
+	unsigned long avg_search[SBA_SEARCH_SAMPLE];
+	unsigned long avg_idx;	/* current index into avg_search */
+	unsigned long used_pages;
+	unsigned long msingle_calls;
+	unsigned long msingle_pages;
+	unsigned long msg_calls;
+	unsigned long msg_pages;
+	unsigned long usingle_calls;
+	unsigned long usingle_pages;
+	unsigned long usg_calls;
+	unsigned long usg_pages;
+#ifdef ALLOW_IOV_BYPASS
+	unsigned long msingle_bypass;
+	unsigned long usingle_bypass;
+	unsigned long msg_bypass;
+#endif
+#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;
+static int reserve_sba_gart = 1;
+
+#define sba_sg_iova(sg) (sg->address)
+#define sba_sg_len(sg) (sg->length)
+#define sba_sg_buffer(sg) (sg->orig_address)
+
+#define GET_IOC(dev)	((struct ioc *) PCI_CONTROLLER(dev)->iommu)
+
+/*
+** DMA_CHUNK_SIZE is used by the SCSI mid-layer to break up
+** (or rather not merge) DMA's into managable chunks.
+** On parisc, this is more of the software/tuning constraint
+** rather than the HW. I/O MMU allocation alogorithms can be
+** faster with smaller size is (to some degree).
+*/
+#define DMA_CHUNK_SIZE  (BITS_PER_LONG*PAGE_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) - 1)]);
+	uint rcnt;
+
+	/* printk(KERN_DEBUG "SBA: %s rp %p bit %d rval 0x%lx\n", */
+	printk("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("%s %2d %p %016Lx\n",
+			(rcnt == (pide & (BITS_PER_LONG - 1)))
+				? "    -->" : "       ",
+			rcnt, ptr, *ptr );
+		rcnt++;
+		ptr++;
+	}
+	printk("%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(" %d : %08lx/%05x %p\n",
+				nents,
+				(unsigned long) sba_sg_iova(startsg),
+				sba_sg_len(startsg),
+				sba_sg_buffer(startsg));
+		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_buffer(the_sg) == 0x0UL)
+			sba_dump_sg(NULL, startsg, nents);
+		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,hint_reg) ((ioc->ibase) | (iovp) | (offset) | ((hint_reg)<<(ioc->hint_shift_pdir)))
+#define SBA_IOVP(ioc,iova) (((iova) & ioc->hint_mask_pdir) & ~(ioc->ibase))
+
+/* FIXME : review these macros to verify correctness and usage */
+#define PDIR_INDEX(iovp)   ((iovp)>>IOVP_SHIFT)
+
+#define RESMAP_MASK(n)    ~(~0UL << (n))
+#define RESMAP_IDX_MASK   (sizeof(unsigned long) - 1)
+
+
+/**
+ * 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.
+ *
+ * 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, unsigned long bits_wanted)
+{
+	unsigned long *res_ptr = ioc->res_hint;
+	unsigned long *res_end = (unsigned long *) &(ioc->res_map[ioc->res_size]);
+	unsigned long pide = ~0UL;
+
+	ASSERT(((unsigned long) ioc->res_hint & (sizeof(unsigned long) - 1UL)) == 0);
+	ASSERT(res_ptr < res_end);
+	if (bits_wanted > (BITS_PER_LONG/2)) {
+		/* Search word at a time - no mask needed */
+		for(; res_ptr < res_end; ++res_ptr) {
+			if (*res_ptr == 0) {
+				*res_ptr = RESMAP_MASK(bits_wanted);
+				pide = ((unsigned long)res_ptr - (unsigned long)ioc->res_map);
+				pide <<= 3;	/* convert to bit address */
+				break;
+			}
+		}
+		/* point to the next word on next pass */
+		res_ptr++;
+		ioc->res_bitshift = 0;
+	} else {
+		/*
+		** 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_order(bits_wanted << PAGE_SHIFT);
+		uint bitshiftcnt = ROUNDUP(ioc->res_bitshift, o);
+		unsigned long mask;
+
+		if (bitshiftcnt >= BITS_PER_LONG) {
+			bitshiftcnt = 0;
+			res_ptr++;
+		}
+		mask = RESMAP_MASK(bits_wanted) << bitshiftcnt;
+
+		DBG_RES("%s() o %ld %p", __FUNCTION__, o, res_ptr);
+		while(res_ptr < res_end)
+		{ 
+			DBG_RES("    %p %lx %lx\n", res_ptr, mask, *res_ptr);
+			ASSERT(0 != mask);
+			if(0 == ((*res_ptr) & mask)) {
+				*res_ptr |= mask;     /* mark resources busy! */
+				pide = ((unsigned long)res_ptr - (unsigned long)ioc->res_map);
+				pide <<= 3;	/* convert to bit address */
+				pide += bitshiftcnt;
+				break;
+			}
+			mask <<= o;
+			bitshiftcnt += o;
+			if (0 == mask) {
+				mask = RESMAP_MASK(bits_wanted);
+				bitshiftcnt=0;
+				res_ptr++;
+			}
+		}
+		/* look in the same word on the next pass */
+		ioc->res_bitshift = bitshiftcnt + bits_wanted;
+	}
+
+	/* wrapped ? */
+	if (res_end <= res_ptr) {
+		ioc->res_hint = (unsigned long *) ioc->res_map;
+		ioc->res_bitshift = 0;
+	} else {
+		ioc->res_hint = res_ptr;
+	}
+	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, size_t size)
+{
+	unsigned int pages_needed = size >> IOVP_SHIFT;
+#ifdef CONFIG_PROC_FS
+	unsigned long itc_start = ia64_get_itc();
+#endif
+	unsigned long pide;
+
+	ASSERT(pages_needed);
+	ASSERT((pages_needed * IOVP_SIZE) <= DMA_CHUNK_SIZE);
+	ASSERT(pages_needed <= BITS_PER_LONG);
+	ASSERT(0 == (size & ~IOVP_MASK));
+
+	/*
+	** "seek and ye shall find"...praying never hurts either...
+	*/
+
+	pide = sba_search_bitmap(ioc, pages_needed);
+	if (pide >= (ioc->res_size << 3)) {
+		pide = sba_search_bitmap(ioc, pages_needed);
+		if (pide >= (ioc->res_size << 3))
+			panic(__FILE__ ": I/O MMU @ %lx is out of mapping resources\n", ioc->ioc_hpa);
+	}
+
+#ifdef ASSERT_PDIR_SANITY
+	/* verify the first enable bit is clear */
+	if(0x00 != ((u8 *) ioc->pdir_base)[pide*sizeof(u64) + 7]) {
+		sba_dump_pdir_entry(ioc, "sba_search_bitmap() botched it?", pide);
+	}
+#endif
+
+	DBG_RES("%s(%x) %d -> %lx hint %x/%x\n",
+		__FUNCTION__, size, pages_needed, pide,
+		(uint) ((unsigned long) ioc->res_hint - (unsigned long) ioc->res_map),
+		ioc->res_bitshift );
+
+#ifdef CONFIG_PROC_FS
+	{
+		unsigned long itc_end = ia64_get_itc();
+		unsigned long tmp = itc_end - itc_start;
+		/* check for roll over */
+		itc_start = (itc_end < itc_start) ?  -(tmp) : (tmp);
+	}
+	ioc->avg_search[ioc->avg_idx++] = itc_start;
+	ioc->avg_idx &= SBA_SEARCH_SAMPLE - 1;
+
+	ioc->used_pages += pages_needed;
+#endif
+
+	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;
+
+	/* 3-bits "bit" address plus 2 (or 3) bits for "byte" == bit in word */
+	unsigned long m = RESMAP_MASK(bits_not_wanted) << (pide & (BITS_PER_LONG - 1));
+
+	DBG_RES("%s( ,%x,%x) %x/%lx %x %p %lx\n",
+		__FUNCTION__, (uint) iova, size,
+		bits_not_wanted, m, pide, res_ptr, *res_ptr);
+
+#ifdef CONFIG_PROC_FS
+	ioc->used_pages -= bits_not_wanted;
+#endif
+
+	ASSERT(m != 0);
+	ASSERT(bits_not_wanted);
+	ASSERT((bits_not_wanted * IOVP_SIZE) <= DMA_CHUNK_SIZE);
+	ASSERT(bits_not_wanted <= BITS_PER_LONG);
+	ASSERT((*res_ptr & m) == m); /* verify same bits are set */
+	*res_ptr &= ~m;
+}
+
+
+/**************************************************************
+*
+*   "Dynamic DMA Mapping" support (aka "Coherent I/O")
+*
+***************************************************************/
+
+#define SBA_DMA_HINT(ioc, val) ((val) << (ioc)->hint_shift_pdir)
+
+
+/**
+ * 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 update_mmu_cache() 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(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 */
+
+		/*
+		** 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 {
+		u32 t = get_order(byte_cnt) + PAGE_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);
+			/* clear I/O Pdir entry "valid" bit first */
+			ioc->pdir_base[off] &= ~(0x80000000000000FFULL);
+			off++;
+			byte_cnt -= IOVP_SIZE;
+		} while (byte_cnt > 0);
+	}
+
+	WRITE_REG(iovp, ioc->ioc_hpa+IOC_PCOM);
+}
+
+/**
+ * sba_map_single - map one buffer and return IOVA for DMA
+ * @dev: instance of PCI owned by the driver that's asking.
+ * @addr:  driver buffer to map.
+ * @size:  number of bytes to map in driver buffer.
+ * @direction:  R/W or both.
+ *
+ * See Documentation/DMA-mapping.txt
+ */
+dma_addr_t
+sba_map_single(struct pci_dev *dev, void *addr, size_t size, int direction)
+{
+	struct ioc *ioc;
+	unsigned long flags; 
+	dma_addr_t iovp;
+	dma_addr_t offset;
+	u64 *pdir_start;
+	int pide;
+#ifdef ALLOW_IOV_BYPASS
+	unsigned long pci_addr = virt_to_phys(addr);
+#endif
+
+	ioc = GET_IOC(dev);
+	ASSERT(ioc);
+
+#ifdef ALLOW_IOV_BYPASS
+	/*
+ 	** Check if the PCI device can DMA to ptr... if so, just return ptr
+ 	*/
+	if ((pci_addr & ~dev->dma_mask) == 0) {
+		/*
+ 		** Device is bit capable of DMA'ing to the buffer...
+		** just return the PCI address of ptr
+ 		*/
+#ifdef CONFIG_PROC_FS
+		spin_lock_irqsave(&ioc->res_lock, flags);
+		ioc->msingle_bypass++;
+		spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif
+		DBG_BYPASS("sba_map_single() bypass mask/addr: 0x%lx/0x%lx\n",
+		           dev->dma_mask, pci_addr);
+		return pci_addr;
+	}
+#endif
+
+	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;
+
+	spin_lock_irqsave(&ioc->res_lock, flags);
+#ifdef ASSERT_PDIR_SANITY
+	if (sba_check_pdir(ioc,"Check before sba_map_single()"))
+		panic("Sanity check failed");
+#endif
+
+#ifdef CONFIG_PROC_FS
+	ioc->msingle_calls++;
+	ioc->msingle_pages += size >> IOVP_SHIFT;
+#endif
+	pide = sba_alloc_range(ioc, size);
+	iovp = (dma_addr_t) pide << IOVP_SHIFT;
+
+	DBG_RUN("%s() 0x%p -> 0x%lx\n",
+		__FUNCTION__, 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++;
+	}
+	/* form complete address */
+#ifdef ASSERT_PDIR_SANITY
+	sba_check_pdir(ioc,"Check after sba_map_single()");
+#endif
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+	return SBA_IOVA(ioc, iovp, offset, DEFAULT_DMA_HINT_REG);
+}
+
+/**
+ * sba_unmap_single - 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.
+ * @direction:  R/W or both.
+ *
+ * See Documentation/DMA-mapping.txt
+ */
+void sba_unmap_single(struct pci_dev *dev, dma_addr_t iova, size_t size,
+		int direction)
+{
+	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 ((iova & ioc->imask) != ioc->ibase) {
+		/*
+		** Address does not fall w/in IOVA, must be bypassing
+		*/
+#ifdef CONFIG_PROC_FS
+		spin_lock_irqsave(&ioc->res_lock, flags);
+		ioc->usingle_bypass++;
+		spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif
+		DBG_BYPASS("sba_unmap_single() bypass addr: 0x%lx\n", iova);
+
+#ifdef ENABLE_MARK_CLEAN
+		if (direction == PCI_DMA_FROMDEVICE) {
+			mark_clean(phys_to_virt(iova), size);
+		}
+#endif
+		return;
+	}
+#endif
+	offset = iova & ~IOVP_MASK;
+
+	DBG_RUN("%s() iovp 0x%lx/%x\n",
+		__FUNCTION__, (long) iova, size);
+
+	iova ^= offset;        /* clear offset bits */
+	size += offset;
+	size = ROUNDUP(size, IOVP_SIZE);
+
+	spin_lock_irqsave(&ioc->res_lock, flags);
+#ifdef CONFIG_PROC_FS
+	ioc->usingle_calls++;
+	ioc->usingle_pages += size >> IOVP_SHIFT;
+#endif
+
+#if DELAYED_RESOURCE_CNT > 0
+	d = &(ioc->saved[ioc->saved_cnt]);
+	d->iova = iova;
+	d->size = size;
+	if (++(ioc->saved_cnt) >= DELAYED_RESOURCE_CNT) {
+		int cnt = ioc->saved_cnt;
+		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 */
+	}
+#else /* DELAYED_RESOURCE_CNT == 0 */
+	sba_mark_invalid(ioc, iova, size);
+	sba_free_range(ioc, iova, size);
+	READ_REG(ioc->ioc_hpa+IOC_PCOM);	/* flush purges */
+#endif /* DELAYED_RESOURCE_CNT == 0 */
+#ifdef ENABLE_MARK_CLEAN
+	if (direction == PCI_DMA_FROMDEVICE) {
+		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 {
+			size_t byte_cnt = size;
+
+			do {
+				addr = phys_to_virt(ioc->pdir_base[off] &
+				                    ~0xE000000000000FFFULL);
+				mark_clean(addr, min(byte_cnt, IOVP_SIZE));
+				off++;
+				byte_cnt -= IOVP_SIZE;
+
+			   } while (byte_cnt > 0);
+		}
+	}
+#endif
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+
+	/* XXX REVISIT for 2.5 Linux - need syncdma for zero-copy support.
+	** For Astro based systems this isn't a big deal WRT performance.
+	** As long as 2.4 kernels copyin/copyout data from/to userspace,
+	** we don't need the syncdma. The issue here is I/O MMU cachelines
+	** are *not* coherent in all cases.  May be hwrev dependent.
+	** Need to investigate more.
+	asm volatile("syncdma");	
+	*/
+}
+
+
+/**
+ * sba_alloc_consistent - allocate/map shared mem for DMA
+ * @hwdev: 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/DMA-mapping.txt
+ */
+void *
+sba_alloc_consistent(struct pci_dev *hwdev, size_t size, dma_addr_t *dma_handle)
+{
+	struct ioc *ioc;
+	void *ret;
+
+	if (!hwdev) {
+		/* only support PCI */
+		*dma_handle = 0;
+		return 0;
+	}
+
+        ret = (void *) __get_free_pages(GFP_ATOMIC, get_order(size));
+
+	if (ret) {
+		memset(ret, 0, size);
+		/*
+		 * REVISIT: if sba_map_single starts needing more
+		 * than dma_mask from the device, this needs to be
+		 * updated.
+		 */
+		ioc = GET_IOC(hwdev);
+		*dma_handle = sba_map_single(ioc->sac_only_dev, ret, size, 0);
+	}
+
+	return ret;
+}
+
+
+/**
+ * sba_free_consistent - free/unmap shared mem for DMA
+ * @hwdev: 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/DMA-mapping.txt
+ */
+void sba_free_consistent(struct pci_dev *hwdev, size_t size, void *vaddr,
+		dma_addr_t dma_handle)
+{
+	sba_unmap_single(hwdev, dma_handle, size, 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 = 0;
+	unsigned long dma_offset = 0;
+
+	dma_sg--;
+	while (nents-- > 0) {
+		int     cnt = sba_sg_len(startsg);
+		sba_sg_len(startsg) = 0;
+
+#ifdef DEBUG_LARGE_SG_ENTRIES
+		if (dump_run_sg)
+			printk(" %2d : %08lx/%05x %p\n",
+				nents,
+				(unsigned long) sba_sg_iova(startsg), cnt,
+				sba_sg_buffer(startsg)
+		);
+#else
+		DBG_RUN_SG(" %d : %08lx/%05x %p\n",
+				nents,
+				(unsigned long) sba_sg_iova(startsg), cnt,
+				sba_sg_buffer(startsg)
+		);
+#endif
+		/*
+		** Look for the start of a new DMA stream
+		*/
+		if ((u64)sba_sg_iova(startsg) & PIDE_FLAG) {
+			u32 pide = (u64)sba_sg_iova(startsg) & ~PIDE_FLAG;
+			dma_offset = (unsigned long) pide & ~IOVP_MASK;
+			sba_sg_iova(startsg) = 0;
+			dma_sg++;
+			sba_sg_iova(dma_sg) = (char *)(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_buffer(startsg);
+			ASSERT(pdirp);
+
+			/* Since multiple Vcontig blocks could make up
+			** one DMA stream, *add* cnt to dma_len.
+			*/
+			sba_sg_len(dma_sg) += cnt;
+			cnt += dma_offset;
+			dma_offset=0;	/* only want offset on first chunk */
+			cnt = ROUNDUP(cnt, IOVP_SIZE);
+#ifdef CONFIG_PROC_FS
+			ioc->msg_pages += cnt >> IOVP_SHIFT;
+#endif
+			do {
+				sba_io_pdir_entry(pdirp, vaddr);
+				vaddr += IOVP_SIZE;
+				cnt -= IOVP_SIZE;
+				pdirp++;
+			} while (cnt > 0);
+		}
+		startsg++;
+	}
+#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 a page boundry.
+**
+** (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 - PAGE_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 seperate 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 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;
+
+	while (nents > 0) {
+		unsigned long vaddr = (unsigned long) (startsg->address); 
+
+		/*
+		** Prepare for first/next DMA stream
+		*/
+		dma_sg = vcontig_sg = startsg;
+		dma_len = vcontig_len = vcontig_end = sba_sg_len(startsg);
+		vcontig_end +=  vaddr;
+		dma_offset = vaddr & ~IOVP_MASK;
+
+		/* PARANOID: clear entries */
+		sba_sg_buffer(startsg) = sba_sg_iova(startsg);
+		sba_sg_iova(startsg) = 0;
+		sba_sg_len(startsg) = 0;
+
+		/*
+		** This loop terminates one iteration "early" since
+		** it's always looking one "ahead".
+		*/
+		while (--nents > 0) {
+			unsigned long vaddr;	/* tmp */
+
+			startsg++;
+
+			/* 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;
+
+			/*
+			** Then look for virtually contiguous blocks.
+			**
+			** append the next transaction?
+			*/
+			vaddr = (unsigned long) sba_sg_iova(startsg);
+			if  (vcontig_end == vaddr)
+			{
+				vcontig_len += sba_sg_len(startsg);
+				vcontig_end += sba_sg_len(startsg);
+				dma_len     += sba_sg_len(startsg);
+				sba_sg_buffer(startsg) = (char *)vaddr;
+				sba_sg_iova(startsg) = 0;
+				sba_sg_len(startsg) = 0;
+				continue;
+			}
+
+#ifdef DEBUG_LARGE_SG_ENTRIES
+			dump_run_sg = (vcontig_len > IOVP_SIZE);
+#endif
+
+			/*
+			** Not virtually contigous.
+			** 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.
+			*/
+			sba_sg_len(vcontig_sg) = vcontig_len;
+
+			vcontig_sg = startsg;
+			vcontig_len = sba_sg_len(startsg);
+
+			/*
+			** 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;
+				sba_sg_buffer(startsg) = (char *)vaddr;
+				sba_sg_iova(startsg) = 0;
+				continue;
+			} else {
+				break;
+			}
+		}
+
+		/*
+		** End of DMA Stream
+		** Terminate last VCONTIG block.
+		** Allocate space for DMA stream.
+		*/
+		sba_sg_len(vcontig_sg) = vcontig_len;
+		dma_len = (dma_len + dma_offset + ~IOVP_MASK) & IOVP_MASK;
+		ASSERT(dma_len <= DMA_CHUNK_SIZE);
+		sba_sg_iova(dma_sg) = (char *) (PIDE_FLAG 
+			| (sba_alloc_range(ioc, dma_len) << IOVP_SHIFT)
+			| dma_offset);
+		n_mappings++;
+	}
+
+	return n_mappings;
+}
+
+
+/**
+ * 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
+ * @direction:  R/W or both.
+ *
+ * See Documentation/DMA-mapping.txt
+ */
+int sba_map_sg(struct pci_dev *dev, struct scatterlist *sglist, int nents,
+		int direction)
+{
+	struct ioc *ioc;
+	int coalesced, filled = 0;
+	unsigned long flags;
+#ifdef ALLOW_IOV_BYPASS
+	struct scatterlist *sg;
+#endif
+
+	DBG_RUN_SG("%s() START %d entries\n", __FUNCTION__, nents);
+	ioc = GET_IOC(dev);
+	ASSERT(ioc);
+
+#ifdef ALLOW_IOV_BYPASS
+	if (dev->dma_mask >= ioc->dma_mask) {
+		for (sg = sglist ; filled < nents ; filled++, sg++){
+			sba_sg_buffer(sg) = sba_sg_iova(sg);
+			sba_sg_iova(sg) = (char *)virt_to_phys(sba_sg_buffer(sg));
+		}
+#ifdef CONFIG_PROC_FS
+		spin_lock_irqsave(&ioc->res_lock, flags);
+		ioc->msg_bypass++;
+		spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif
+		return filled;
+	}
+#endif
+	/* Fast path single entry scatterlists. */
+	if (nents == 1) {
+		sba_sg_buffer(sglist) = sba_sg_iova(sglist);
+		sba_sg_iova(sglist) = (char *)sba_map_single(dev,
+						sba_sg_buffer(sglist),
+						sba_sg_len(sglist), direction);
+#ifdef CONFIG_PROC_FS
+		/*
+		** Should probably do some stats counting, but trying to
+		** be precise quickly starts wasting CPU time.
+		*/
+#endif
+		return 1;
+	}
+
+	spin_lock_irqsave(&ioc->res_lock, flags);
+
+#ifdef ASSERT_PDIR_SANITY
+	if (sba_check_pdir(ioc,"Check before sba_map_sg()"))
+	{
+		sba_dump_sg(ioc, sglist, nents);
+		panic("Check before sba_map_sg()");
+	}
+#endif
+
+#ifdef CONFIG_PROC_FS
+	ioc->msg_calls++;
+#endif
+
+	/*
+	** 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, sglist, nents);
+ 
+	/*
+	** 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
+	if (sba_check_pdir(ioc,"Check after sba_map_sg()"))
+	{
+		sba_dump_sg(ioc, sglist, nents);
+		panic("Check after sba_map_sg()\n");
+	}
+#endif
+
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+
+	ASSERT(coalesced == filled);
+	DBG_RUN_SG("%s() DONE %d mappings\n", __FUNCTION__, filled);
+
+	return filled;
+}
+
+
+/**
+ * sba_unmap_sg - 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
+ * @direction:  R/W or both.
+ *
+ * See Documentation/DMA-mapping.txt
+ */
+void sba_unmap_sg(struct pci_dev *dev, struct scatterlist *sglist, int nents,
+		int direction)
+{
+	struct ioc *ioc;
+#ifdef ASSERT_PDIR_SANITY
+	unsigned long flags;
+#endif
+
+	DBG_RUN_SG("%s() START %d entries,  %p,%x\n",
+		__FUNCTION__, nents, sba_sg_buffer(sglist), sglist->length);
+
+	ioc = GET_IOC(dev);
+	ASSERT(ioc);
+
+#ifdef CONFIG_PROC_FS
+	ioc->usg_calls++;
+#endif
+
+#ifdef ASSERT_PDIR_SANITY
+	spin_lock_irqsave(&ioc->res_lock, flags);
+	sba_check_pdir(ioc,"Check before sba_unmap_sg()");
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif
+
+	while (sba_sg_len(sglist) && nents--) {
+
+		sba_unmap_single(dev, (dma_addr_t)sba_sg_iova(sglist),
+		                 sba_sg_len(sglist), direction);
+#ifdef CONFIG_PROC_FS
+		/*
+		** This leaves inconsistent data in the stats, but we can't
+		** tell which sg lists were mapped by map_single and which
+		** were coalesced to a single entry.  The stats are fun,
+		** but speed is more important.
+		*/
+		ioc->usg_pages += (((u64)sba_sg_iova(sglist) & ~IOVP_MASK) + sba_sg_len(sglist) + IOVP_SIZE - 1) >> PAGE_SHIFT;
+#endif
+		++sglist;
+	}
+
+	DBG_RUN_SG("%s() DONE (nents %d)\n", __FUNCTION__,  nents);
+
+#ifdef ASSERT_PDIR_SANITY
+	spin_lock_irqsave(&ioc->res_lock, flags);
+	sba_check_pdir(ioc,"Check after sba_unmap_sg()");
+	spin_unlock_irqrestore(&ioc->res_lock, flags);
+#endif
+
+}
+
+unsigned long
+sba_dma_address (struct scatterlist *sg)
+{
+	return ((unsigned long)sba_sg_iova(sg));
+}
+
+int
+sba_dma_supported (struct pci_dev *dev, u64 mask)
+{
+	return 1;
+}
+
+/**************************************************************
+*
+*   Initialization and claim
+*
+***************************************************************/
+
+static void __init
+ioc_iova_init(struct ioc *ioc)
+{
+	u32 iova_space_mask;
+	int iov_order, tcnfg;
+	int agp_found = 0;
+	struct pci_dev *device;
+
+	/*
+	** 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->iov_size = ~(READ_REG(ioc->ioc_hpa + IOC_IMASK) & 0xFFFFFFFFUL) + 1;
+
+	if (ioc->ibase == 0) {
+		if (((unsigned long) ioc->ioc_hpa & 0x3000UL) == 0x2000)
+			ioc->ibase = 0xc0000000;
+		else
+			ioc->ibase = 0x80000000;
+		printk("WARNING: IBASE is zero; setting to 0x%lx\n", ioc->ibase);
+	}
+
+	if (ioc->ibase < 0xfed00000UL && ioc->ibase + ioc->iov_size >= 0xfee00000UL) {
+		printk("WARNING: IOV space overlaps local config and interrupt message, truncating\n");
+		ioc->iov_size /= 2;
+	}
+
+	/*
+	** iov_order is always based on a 1GB IOVA space since we want to
+	** turn on the other half for AGP GART.
+	*/
+	iov_order = get_order(ioc->iov_size >> (IOVP_SHIFT - PAGE_SHIFT));
+	ioc->pdir_size = (ioc->iov_size / IOVP_SIZE) * sizeof(u64);
+
+	DBG_INIT("%s() hpa 0x%lx IOV %dMB (%d bits) PDIR size 0x%0x\n",
+		__FUNCTION__, ioc->ioc_hpa, ioc->iov_size >> 20,
+		iov_order + PAGE_SHIFT, ioc->pdir_size);
+
+	/* FIXME : DMA HINTs not used */
+	ioc->hint_shift_pdir = iov_order + PAGE_SHIFT;
+	ioc->hint_mask_pdir = ~(0x3 << (iov_order + PAGE_SHIFT));
+
+	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() pdir %p size %x hint_shift_pdir %x hint_mask_pdir %lx\n",
+		__FUNCTION__, ioc->pdir_base, ioc->pdir_size,
+		ioc->hint_shift_pdir, ioc->hint_mask_pdir);
+
+	ASSERT((((unsigned long) ioc->pdir_base) & PAGE_MASK) == (unsigned long) ioc->pdir_base);
+	WRITE_REG(virt_to_phys(ioc->pdir_base), ioc->ioc_hpa + IOC_PDIR_BASE);
+
+	DBG_INIT(" base %p\n", ioc->pdir_base);
+
+	/* build IMASK for IOC and Elroy */
+	iova_space_mask =  0xffffffff;
+	iova_space_mask <<= (iov_order + PAGE_SHIFT);
+	ioc->imask = iova_space_mask;
+
+	DBG_INIT("%s() IOV base 0x%lx mask 0x%0lx\n",
+		__FUNCTION__, ioc->ibase, ioc->imask);
+
+	/*
+	** FIXME: Hint registers are programmed with default hint
+	** values during boot, so hints should be sane even if we
+	** can't reprogram them the way drivers want.
+	*/
+	WRITE_REG(ioc->imask, ioc->ioc_hpa + IOC_IMASK);
+
+	/*
+	** Setting the upper bits makes checking for bypass addresses
+	** a little faster later on.
+	*/
+	ioc->imask |= 0xFFFFFFFF00000000UL;
+
+	/* Set I/O PDIR Page size to system page size */
+	switch (PAGE_SHIFT) {
+		case 12: tcnfg = 0; break;	/*  4K */
+		case 13: tcnfg = 1; break;	/*  8K */
+		case 14: tcnfg = 2; break;	/* 16K */
+		case 16: tcnfg = 3; break;	/* 64K */
+		default:
+			panic(PFX "Unsupported system page size %d",
+				1 << PAGE_SHIFT);
+			break;
+	}
+	WRITE_REG(tcnfg, ioc->ioc_hpa + IOC_TCNFG);
+
+	/*
+	** Program the IOC's ibase and enable IOVA translation
+	** Bit zero == enable bit.
+	*/
+	WRITE_REG(ioc->ibase | 1, ioc->ioc_hpa + IOC_IBASE);
+
+	/*
+	** Clear I/O TLB of any possible entries.
+	** (Yes. This is a bit paranoid...but so what)
+	*/
+	WRITE_REG(0 | 31, ioc->ioc_hpa + IOC_PCOM);
+
+	/*
+	** 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.
+	*/
+	pci_for_each_dev(device)
+		agp_found |= pci_find_capability(device, PCI_CAP_ID_AGP);
+
+	if (agp_found && reserve_sba_gart) {
+		DBG_INIT("%s: AGP device found, reserving half of IOVA for GART support\n", __FUNCTION__);
+		ioc->pdir_size /= 2;
+		((u64 *)ioc->pdir_base)[PDIR_INDEX(ioc->iov_size/2)] = ZX1_SBA_IOMMU_COOKIE;
+	}
+}
+
+static void __init
+ioc_resource_init(struct ioc *ioc)
+{
+	spin_lock_init(&ioc->res_lock);
+
+	/* resource map size dictated by pdir_size */
+	ioc->res_size = ioc->pdir_size / sizeof(u64); /* entries */
+	ioc->res_size >>= 3;  /* convert bit count to byte count */
+	DBG_INIT("%s() res_size 0x%x\n", __FUNCTION__, 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
+
+	DBG_INIT("%s() res_map %x %p\n", __FUNCTION__,
+		 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_consistent() must return a DMA address which is
+	 * SAC (single address cycle) addressable, so allocate a
+	 * pseudo-device to enforce that.
+	 */
+	sac = kmalloc(sizeof(*sac), GFP_KERNEL);
+	if (!sac)
+		panic(PFX "Couldn't allocate struct pci_dev");
+	memset(sac, 0, sizeof(*sac));
+
+	controller = kmalloc(sizeof(*controller), GFP_KERNEL);
+	if (!controller)
+		panic(PFX "Couldn't allocate struct pci_controller");
+	memset(controller, 0, sizeof(*controller));
+
+	controller->iommu = ioc;
+	sac->sysdata = controller;
+	sac->dma_mask = 0xFFFFFFFFUL;
+	ioc->sac_only_dev = sac;
+}
+
+static void __init
+ioc_zx1_init(struct ioc *ioc)
+{
+	if (ioc->rev < 0x20)
+		panic(PFX "IOC 2.0 or later required for IOMMU support\n");
+
+	ioc->dma_mask = 0xFFFFFFFFFFUL;
+}
+
+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 },
+	{ REO_IOC_ID, "REO" },
+};
+
+static struct ioc * __init
+ioc_init(u64 hpa, void *handle)
+{
+	struct ioc *ioc;
+	struct ioc_iommu *info;
+
+	ioc = kmalloc(sizeof(*ioc), GFP_KERNEL);
+	if (!ioc)
+		return NULL;
+
+	memset(ioc, 0, sizeof(*ioc));
+
+	ioc->next = ioc_list;
+	ioc_list = ioc;
+
+	ioc->handle = handle;
+	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);
+		}
+	}
+	if (!ioc->name)
+		ioc->name = "Unknown";
+
+	ioc_iova_init(ioc);
+	ioc_resource_init(ioc);
+	ioc_sac_init(ioc);
+
+	printk(KERN_INFO PFX
+		"Found %s IOC %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);
+
+	return ioc;
+}
+
+
+
+/**************************************************************************
+**
+**   SBA initialization code (HW and SW)
+**
+**   o identify SBA chip itself
+**   o FIXME: initialize DMA hints for reasonable defaults
+**
+**************************************************************************/
+
+#ifdef CONFIG_PROC_FS
+static int
+sba_proc_info_one(char *buf, struct ioc *ioc)
+{
+	int total_pages = (int) (ioc->res_size << 3); /* 8 bits per byte */
+	unsigned long i = 0, avg = 0, min, max;
+
+	sprintf(buf, "Hewlett Packard %s IOC rev %d.%d\n",
+		ioc->name, ((ioc->rev >> 4) & 0xF), (ioc->rev & 0xF));
+	sprintf(buf, "%sIO PDIR size    : %d bytes (%d entries)\n",
+		buf,
+		(int) ((ioc->res_size << 3) * sizeof(u64)), /* 8 bits/byte */
+		total_pages);
+
+	sprintf(buf, "%sIO PDIR entries : %ld free  %ld used (%d%%)\n", buf,
+		total_pages - ioc->used_pages, ioc->used_pages,
+		(int) (ioc->used_pages * 100 / total_pages));
+	
+	sprintf(buf, "%sResource bitmap : %d bytes (%d pages)\n", 
+		buf, ioc->res_size, ioc->res_size << 3);   /* 8 bits per byte */
+
+	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;
+	sprintf(buf, "%s  Bitmap search : %ld/%ld/%ld (min/avg/max CPU Cycles)\n",
+		buf, min, avg, max);
+
+	sprintf(buf, "%spci_map_single(): %12ld calls  %12ld pages (avg %d/1000)\n",
+		buf, ioc->msingle_calls, ioc->msingle_pages,
+		(int) ((ioc->msingle_pages * 1000)/ioc->msingle_calls));
+#ifdef ALLOW_IOV_BYPASS
+	sprintf(buf, "%spci_map_single(): %12ld bypasses\n",
+	        buf, ioc->msingle_bypass);
+#endif
+
+	sprintf(buf, "%spci_unmap_single: %12ld calls  %12ld pages (avg %d/1000)\n",
+		buf, ioc->usingle_calls, ioc->usingle_pages,
+		(int) ((ioc->usingle_pages * 1000)/ioc->usingle_calls));
+#ifdef ALLOW_IOV_BYPASS
+	sprintf(buf, "%spci_unmap_single: %12ld bypasses\n",
+	        buf, ioc->usingle_bypass);
+#endif
+
+	sprintf(buf, "%spci_map_sg()    : %12ld calls  %12ld pages (avg %d/1000)\n",
+		buf, ioc->msg_calls, ioc->msg_pages,
+		(int) ((ioc->msg_pages * 1000)/ioc->msg_calls));
+#ifdef ALLOW_IOV_BYPASS
+	sprintf(buf, "%spci_map_sg()    : %12ld bypasses\n",
+	        buf, ioc->msg_bypass);
+#endif
+
+	sprintf(buf, "%spci_unmap_sg()  : %12ld calls  %12ld pages (avg %d/1000)\n",
+		buf, ioc->usg_calls, ioc->usg_pages,
+		(int) ((ioc->usg_pages * 1000)/ioc->usg_calls));
+
+	return strlen(buf);
+}
+
+static int
+sba_proc_info(char *buf, char **start, off_t offset, int len)
+{
+	struct ioc *ioc;
+	char *base = buf;
+
+	for (ioc = ioc_list; ioc; ioc = ioc->next) {
+		buf += sba_proc_info_one(buf, ioc);
+	}
+
+	return strlen(base);
+}
+
+static int
+sba_resource_map_one(char *buf, struct ioc *ioc)
+{
+	unsigned int *res_ptr = (unsigned int *)ioc->res_map;
+	int i;
+
+	buf[0] = '\0';
+	for(i = 0; i < (ioc->res_size / sizeof(unsigned int)); ++i, ++res_ptr) {
+		if ((i & 7) == 0)
+		    strcat(buf,"\n   ");
+		sprintf(buf, "%s %08x", buf, *res_ptr);
+	}
+	strcat(buf, "\n");
+
+	return strlen(buf);
+}
+
+static int
+sba_resource_map(char *buf, char **start, off_t offset, int len)
+{
+	struct ioc *ioc;
+	char *base = buf;
+
+	for (ioc = ioc_list; ioc; ioc = ioc->next) {
+		buf += sba_resource_map_one(buf, ioc);
+	}
+
+	return strlen(base);
+}
+#endif
+
+void
+sba_enable_device(struct pci_dev *dev)
+{
+	acpi_handle handle, parent;
+	acpi_status status;
+	struct ioc *ioc;
+
+	handle = PCI_CONTROLLER(dev)->acpi_handle;
+	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(dev)->iommu = ioc;
+				return;
+			}
+
+		status = acpi_get_parent(handle, &parent);
+		handle = parent;
+	} while (ACPI_SUCCESS(status));
+
+	printk("No IOC for %s in ACPI\n", dev->slot_name);
+}
+
+static int __init
+acpi_sba_ioc_add(struct acpi_device *device)
+{
+	struct ioc *ioc;
+	acpi_status status;
+	u64 hpa, length;
+
+	/*
+	 * Only SBA appears in ACPI namespace.  It encloses the PCI
+	 * root bridges, and its CSR space includes the IOC function.
+	 */
+	status = acpi_hp_csr_space(device->handle, &hpa, &length);
+	if (ACPI_FAILURE(status))
+		return 1;
+	ioc = ioc_init(hpa + ZX1_IOC_OFFSET, device->handle);
+	if (!ioc)
+		return 1;
+
+	return 0;
+}
+
+static int __init
+acpi_ioc_add(struct acpi_device *device)
+{
+	struct ioc *ioc;
+	acpi_status status;
+	u64 hpa, length;
+
+	status = acpi_hp_csr_space(device->handle, &hpa, &length);
+	if (ACPI_FAILURE(status))
+		return 1;
+	ioc = ioc_init(hpa, device->handle);
+	if (!ioc)
+		return 1;
+
+	return 0;
+}
+
+static struct acpi_driver acpi_sba_ioc_driver = {
+	name:		"IOC IOMMU Driver",
+	ids:		"HWP0001",
+	ops: {
+		add:	acpi_sba_ioc_add,
+     },
+};
+
+static struct acpi_driver acpi_ioc_driver = {
+	name:		"IOC IOMMU Driver",
+	ids:		"HWP0004",
+	ops: {
+		add:	acpi_ioc_add,
+     },
+};
+
+void __init
+ioc_acpi_init(void)
+{
+	acpi_bus_register_driver(&acpi_sba_ioc_driver);
+	acpi_bus_register_driver(&acpi_ioc_driver);
+}
+
+void __init
+sba_init(void)
+{
+	ioc_acpi_init();
+
+#ifdef CONFIG_PROC_FS
+	if (ioc_list) {
+		struct proc_dir_entry * proc_mckinley_root;
+
+		proc_mckinley_root = proc_mkdir("bus/mckinley",0);
+		create_proc_info_entry(ioc_list->name, 0, proc_mckinley_root, sba_proc_info);
+		create_proc_info_entry("bitmap", 0, proc_mckinley_root, sba_resource_map);
+	}
+#endif
+}
+
+static int __init
+nosbagart(char *str)
+{
+	reserve_sba_gart = 0;
+	return 1;
+}
+
+__setup("nosbagart", nosbagart);
+
+EXPORT_SYMBOL(sba_init);
+EXPORT_SYMBOL(sba_map_single);
+EXPORT_SYMBOL(sba_unmap_single);
+EXPORT_SYMBOL(sba_map_sg);
+EXPORT_SYMBOL(sba_unmap_sg);
+EXPORT_SYMBOL(sba_dma_address);
+EXPORT_SYMBOL(sba_dma_supported);
+EXPORT_SYMBOL(sba_alloc_consistent);
+EXPORT_SYMBOL(sba_free_consistent);

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)