Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 567 insertions, 0 deletions

diff --git a/arch/ppc64/kernel/iommu.c b/arch/ppc64/kernel/iommu.c
new file mode 100644
index 00000000000..344164681d2
--- /dev/null
+++ b/arch/ppc64/kernel/iommu.c
@@ -0,0 +1,567 @@
+/*
+ * arch/ppc64/kernel/iommu.c
+ * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
+ * 
+ * Rewrite, cleanup, new allocation schemes, virtual merging: 
+ * Copyright (C) 2004 Olof Johansson, IBM Corporation
+ *               and  Ben. Herrenschmidt, IBM Corporation
+ *
+ * Dynamic DMA mapping support, bus-independent parts.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/dma-mapping.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/iommu.h>
+#include <asm/pci-bridge.h>
+#include <asm/machdep.h>
+
+#define DBG(...)
+
+#ifdef CONFIG_IOMMU_VMERGE
+static int novmerge = 0;
+#else
+static int novmerge = 1;
+#endif
+
+static int __init setup_iommu(char *str)
+{
+	if (!strcmp(str, "novmerge"))
+		novmerge = 1;
+	else if (!strcmp(str, "vmerge"))
+		novmerge = 0;
+	return 1;
+}
+
+__setup("iommu=", setup_iommu);
+
+static unsigned long iommu_range_alloc(struct iommu_table *tbl,
+                                       unsigned long npages,
+                                       unsigned long *handle,
+                                       unsigned int align_order)
+{ 
+	unsigned long n, end, i, start;
+	unsigned long limit;
+	int largealloc = npages > 15;
+	int pass = 0;
+	unsigned long align_mask;
+
+	align_mask = 0xffffffffffffffffl >> (64 - align_order);
+
+	/* This allocator was derived from x86_64's bit string search */
+
+	/* Sanity check */
+	if (unlikely(npages) == 0) {
+		if (printk_ratelimit())
+			WARN_ON(1);
+		return DMA_ERROR_CODE;
+	}
+
+	if (handle && *handle)
+		start = *handle;
+	else
+		start = largealloc ? tbl->it_largehint : tbl->it_hint;
+
+	/* Use only half of the table for small allocs (15 pages or less) */
+	limit = largealloc ? tbl->it_size : tbl->it_halfpoint;
+
+	if (largealloc && start < tbl->it_halfpoint)
+		start = tbl->it_halfpoint;
+
+	/* The case below can happen if we have a small segment appended
+	 * to a large, or when the previous alloc was at the very end of
+	 * the available space. If so, go back to the initial start.
+	 */
+	if (start >= limit)
+		start = largealloc ? tbl->it_largehint : tbl->it_hint;
+	
+ again:
+
+	n = find_next_zero_bit(tbl->it_map, limit, start);
+
+	/* Align allocation */
+	n = (n + align_mask) & ~align_mask;
+
+	end = n + npages;
+
+	if (unlikely(end >= limit)) {
+		if (likely(pass < 2)) {
+			/* First failure, just rescan the half of the table.
+			 * Second failure, rescan the other half of the table.
+			 */
+			start = (largealloc ^ pass) ? tbl->it_halfpoint : 0;
+			limit = pass ? tbl->it_size : limit;
+			pass++;
+			goto again;
+		} else {
+			/* Third failure, give up */
+			return DMA_ERROR_CODE;
+		}
+	}
+
+	for (i = n; i < end; i++)
+		if (test_bit(i, tbl->it_map)) {
+			start = i+1;
+			goto again;
+		}
+
+	for (i = n; i < end; i++)
+		__set_bit(i, tbl->it_map);
+
+	/* Bump the hint to a new block for small allocs. */
+	if (largealloc) {
+		/* Don't bump to new block to avoid fragmentation */
+		tbl->it_largehint = end;
+	} else {
+		/* Overflow will be taken care of at the next allocation */
+		tbl->it_hint = (end + tbl->it_blocksize - 1) &
+		                ~(tbl->it_blocksize - 1);
+	}
+
+	/* Update handle for SG allocations */
+	if (handle)
+		*handle = end;
+
+	return n;
+}
+
+static dma_addr_t iommu_alloc(struct iommu_table *tbl, void *page,
+		       unsigned int npages, enum dma_data_direction direction,
+		       unsigned int align_order)
+{
+	unsigned long entry, flags;
+	dma_addr_t ret = DMA_ERROR_CODE;
+	
+	spin_lock_irqsave(&(tbl->it_lock), flags);
+
+	entry = iommu_range_alloc(tbl, npages, NULL, align_order);
+
+	if (unlikely(entry == DMA_ERROR_CODE)) {
+		spin_unlock_irqrestore(&(tbl->it_lock), flags);
+		return DMA_ERROR_CODE;
+	}
+
+	entry += tbl->it_offset;	/* Offset into real TCE table */
+	ret = entry << PAGE_SHIFT;	/* Set the return dma address */
+
+	/* Put the TCEs in the HW table */
+	ppc_md.tce_build(tbl, entry, npages, (unsigned long)page & PAGE_MASK,
+			 direction);
+
+
+	/* Flush/invalidate TLB caches if necessary */
+	if (ppc_md.tce_flush)
+		ppc_md.tce_flush(tbl);
+
+	spin_unlock_irqrestore(&(tbl->it_lock), flags);
+
+	/* Make sure updates are seen by hardware */
+	mb();
+
+	return ret;
+}
+
+static void __iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr, 
+			 unsigned int npages)
+{
+	unsigned long entry, free_entry;
+	unsigned long i;
+
+	entry = dma_addr >> PAGE_SHIFT;
+	free_entry = entry - tbl->it_offset;
+
+	if (((free_entry + npages) > tbl->it_size) ||
+	    (entry < tbl->it_offset)) {
+		if (printk_ratelimit()) {
+			printk(KERN_INFO "iommu_free: invalid entry\n");
+			printk(KERN_INFO "\tentry     = 0x%lx\n", entry); 
+			printk(KERN_INFO "\tdma_addr  = 0x%lx\n", (u64)dma_addr);
+			printk(KERN_INFO "\tTable     = 0x%lx\n", (u64)tbl);
+			printk(KERN_INFO "\tbus#      = 0x%lx\n", (u64)tbl->it_busno);
+			printk(KERN_INFO "\tsize      = 0x%lx\n", (u64)tbl->it_size);
+			printk(KERN_INFO "\tstartOff  = 0x%lx\n", (u64)tbl->it_offset);
+			printk(KERN_INFO "\tindex     = 0x%lx\n", (u64)tbl->it_index);
+			WARN_ON(1);
+		}
+		return;
+	}
+
+	ppc_md.tce_free(tbl, entry, npages);
+	
+	for (i = 0; i < npages; i++)
+		__clear_bit(free_entry+i, tbl->it_map);
+}
+
+static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
+		unsigned int npages)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&(tbl->it_lock), flags);
+
+	__iommu_free(tbl, dma_addr, npages);
+
+	/* Make sure TLB cache is flushed if the HW needs it. We do
+	 * not do an mb() here on purpose, it is not needed on any of
+	 * the current platforms.
+	 */
+	if (ppc_md.tce_flush)
+		ppc_md.tce_flush(tbl);
+
+	spin_unlock_irqrestore(&(tbl->it_lock), flags);
+}
+
+int iommu_map_sg(struct device *dev, struct iommu_table *tbl,
+		struct scatterlist *sglist, int nelems,
+		enum dma_data_direction direction)
+{
+	dma_addr_t dma_next = 0, dma_addr;
+	unsigned long flags;
+	struct scatterlist *s, *outs, *segstart;
+	int outcount;
+	unsigned long handle;
+
+	BUG_ON(direction == DMA_NONE);
+
+	if ((nelems == 0) || !tbl)
+		return 0;
+
+	outs = s = segstart = &sglist[0];
+	outcount = 1;
+	handle = 0;
+
+	/* Init first segment length for backout at failure */
+	outs->dma_length = 0;
+
+	DBG("mapping %d elements:\n", nelems);
+
+	spin_lock_irqsave(&(tbl->it_lock), flags);
+
+	for (s = outs; nelems; nelems--, s++) {
+		unsigned long vaddr, npages, entry, slen;
+
+		slen = s->length;
+		/* Sanity check */
+		if (slen == 0) {
+			dma_next = 0;
+			continue;
+		}
+		/* Allocate iommu entries for that segment */
+		vaddr = (unsigned long)page_address(s->page) + s->offset;
+		npages = PAGE_ALIGN(vaddr + slen) - (vaddr & PAGE_MASK);
+		npages >>= PAGE_SHIFT;
+		entry = iommu_range_alloc(tbl, npages, &handle, 0);
+
+		DBG("  - vaddr: %lx, size: %lx\n", vaddr, slen);
+
+		/* Handle failure */
+		if (unlikely(entry == DMA_ERROR_CODE)) {
+			if (printk_ratelimit())
+				printk(KERN_INFO "iommu_alloc failed, tbl %p vaddr %lx"
+				       " npages %lx\n", tbl, vaddr, npages);
+			goto failure;
+		}
+
+		/* Convert entry to a dma_addr_t */
+		entry += tbl->it_offset;
+		dma_addr = entry << PAGE_SHIFT;
+		dma_addr |= s->offset;
+
+		DBG("  - %lx pages, entry: %lx, dma_addr: %lx\n",
+			    npages, entry, dma_addr);
+
+		/* Insert into HW table */
+		ppc_md.tce_build(tbl, entry, npages, vaddr & PAGE_MASK, direction);
+
+		/* If we are in an open segment, try merging */
+		if (segstart != s) {
+			DBG("  - trying merge...\n");
+			/* We cannot merge if:
+			 * - allocated dma_addr isn't contiguous to previous allocation
+			 */
+			if (novmerge || (dma_addr != dma_next)) {
+				/* Can't merge: create a new segment */
+				segstart = s;
+				outcount++; outs++;
+				DBG("    can't merge, new segment.\n");
+			} else {
+				outs->dma_length += s->length;
+				DBG("    merged, new len: %lx\n", outs->dma_length);
+			}
+		}
+
+		if (segstart == s) {
+			/* This is a new segment, fill entries */
+			DBG("  - filling new segment.\n");
+			outs->dma_address = dma_addr;
+			outs->dma_length = slen;
+		}
+
+		/* Calculate next page pointer for contiguous check */
+		dma_next = dma_addr + slen;
+
+		DBG("  - dma next is: %lx\n", dma_next);
+	}
+
+	/* Flush/invalidate TLB caches if necessary */
+	if (ppc_md.tce_flush)
+		ppc_md.tce_flush(tbl);
+
+	spin_unlock_irqrestore(&(tbl->it_lock), flags);
+
+	/* Make sure updates are seen by hardware */
+	mb();
+
+	DBG("mapped %d elements:\n", outcount);
+
+	/* For the sake of iommu_free_sg, we clear out the length in the
+	 * next entry of the sglist if we didn't fill the list completely
+	 */
+	if (outcount < nelems) {
+		outs++;
+		outs->dma_address = DMA_ERROR_CODE;
+		outs->dma_length = 0;
+	}
+	return outcount;
+
+ failure:
+	for (s = &sglist[0]; s <= outs; s++) {
+		if (s->dma_length != 0) {
+			unsigned long vaddr, npages;
+
+			vaddr = s->dma_address & PAGE_MASK;
+			npages = (PAGE_ALIGN(s->dma_address + s->dma_length) - vaddr)
+				>> PAGE_SHIFT;
+			__iommu_free(tbl, vaddr, npages);
+		}
+	}
+	spin_unlock_irqrestore(&(tbl->it_lock), flags);
+	return 0;
+}
+
+
+void iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist,
+		int nelems, enum dma_data_direction direction)
+{
+	unsigned long flags;
+
+	BUG_ON(direction == DMA_NONE);
+
+	if (!tbl)
+		return;
+
+	spin_lock_irqsave(&(tbl->it_lock), flags);
+
+	while (nelems--) {
+		unsigned int npages;
+		dma_addr_t dma_handle = sglist->dma_address;
+
+		if (sglist->dma_length == 0)
+			break;
+		npages = (PAGE_ALIGN(dma_handle + sglist->dma_length)
+			  - (dma_handle & PAGE_MASK)) >> PAGE_SHIFT;
+		__iommu_free(tbl, dma_handle, npages);
+		sglist++;
+	}
+
+	/* Flush/invalidate TLBs if necessary. As for iommu_free(), we
+	 * do not do an mb() here, the affected platforms do not need it
+	 * when freeing.
+	 */
+	if (ppc_md.tce_flush)
+		ppc_md.tce_flush(tbl);
+
+	spin_unlock_irqrestore(&(tbl->it_lock), flags);
+}
+
+/*
+ * Build a iommu_table structure.  This contains a bit map which
+ * is used to manage allocation of the tce space.
+ */
+struct iommu_table *iommu_init_table(struct iommu_table *tbl)
+{
+	unsigned long sz;
+	static int welcomed = 0;
+
+	/* Set aside 1/4 of the table for large allocations. */
+	tbl->it_halfpoint = tbl->it_size * 3 / 4;
+
+	/* number of bytes needed for the bitmap */
+	sz = (tbl->it_size + 7) >> 3;
+
+	tbl->it_map = (unsigned long *)__get_free_pages(GFP_ATOMIC, get_order(sz));
+	if (!tbl->it_map)
+		panic("iommu_init_table: Can't allocate %ld bytes\n", sz);
+
+	memset(tbl->it_map, 0, sz);
+
+	tbl->it_hint = 0;
+	tbl->it_largehint = tbl->it_halfpoint;
+	spin_lock_init(&tbl->it_lock);
+
+	if (!welcomed) {
+		printk(KERN_INFO "IOMMU table initialized, virtual merging %s\n",
+		       novmerge ? "disabled" : "enabled");
+		welcomed = 1;
+	}
+
+	return tbl;
+}
+
+void iommu_free_table(struct device_node *dn)
+{
+	struct iommu_table *tbl = dn->iommu_table;
+	unsigned long bitmap_sz, i;
+	unsigned int order;
+
+	if (!tbl || !tbl->it_map) {
+		printk(KERN_ERR "%s: expected TCE map for %s\n", __FUNCTION__,
+				dn->full_name);
+		return;
+	}
+
+	/* verify that table contains no entries */
+	/* it_size is in entries, and we're examining 64 at a time */
+	for (i = 0; i < (tbl->it_size/64); i++) {
+		if (tbl->it_map[i] != 0) {
+			printk(KERN_WARNING "%s: Unexpected TCEs for %s\n",
+				__FUNCTION__, dn->full_name);
+			break;
+		}
+	}
+
+	/* calculate bitmap size in bytes */
+	bitmap_sz = (tbl->it_size + 7) / 8;
+
+	/* free bitmap */
+	order = get_order(bitmap_sz);
+	free_pages((unsigned long) tbl->it_map, order);
+
+	/* free table */
+	kfree(tbl);
+}
+
+/* Creates TCEs for a user provided buffer.  The user buffer must be
+ * contiguous real kernel storage (not vmalloc).  The address of the buffer
+ * passed here is the kernel (virtual) address of the buffer.  The buffer
+ * need not be page aligned, the dma_addr_t returned will point to the same
+ * byte within the page as vaddr.
+ */
+dma_addr_t iommu_map_single(struct iommu_table *tbl, void *vaddr,
+		size_t size, enum dma_data_direction direction)
+{
+	dma_addr_t dma_handle = DMA_ERROR_CODE;
+	unsigned long uaddr;
+	unsigned int npages;
+
+	BUG_ON(direction == DMA_NONE);
+
+	uaddr = (unsigned long)vaddr;
+	npages = PAGE_ALIGN(uaddr + size) - (uaddr & PAGE_MASK);
+	npages >>= PAGE_SHIFT;
+
+	if (tbl) {
+		dma_handle = iommu_alloc(tbl, vaddr, npages, direction, 0);
+		if (dma_handle == DMA_ERROR_CODE) {
+			if (printk_ratelimit())  {
+				printk(KERN_INFO "iommu_alloc failed, "
+						"tbl %p vaddr %p npages %d\n",
+						tbl, vaddr, npages);
+			}
+		} else
+			dma_handle |= (uaddr & ~PAGE_MASK);
+	}
+
+	return dma_handle;
+}
+
+void iommu_unmap_single(struct iommu_table *tbl, dma_addr_t dma_handle,
+		size_t size, enum dma_data_direction direction)
+{
+	BUG_ON(direction == DMA_NONE);
+
+	if (tbl)
+		iommu_free(tbl, dma_handle, (PAGE_ALIGN(dma_handle + size) -
+					(dma_handle & PAGE_MASK)) >> PAGE_SHIFT);
+}
+
+/* Allocates a contiguous real buffer and creates mappings over it.
+ * Returns the virtual address of the buffer and sets dma_handle
+ * to the dma address (mapping) of the first page.
+ */
+void *iommu_alloc_coherent(struct iommu_table *tbl, size_t size,
+		dma_addr_t *dma_handle, unsigned int __nocast flag)
+{
+	void *ret = NULL;
+	dma_addr_t mapping;
+	unsigned int npages, order;
+
+	size = PAGE_ALIGN(size);
+	npages = size >> PAGE_SHIFT;
+	order = get_order(size);
+
+ 	/*
+	 * Client asked for way too much space.  This is checked later
+	 * anyway.  It is easier to debug here for the drivers than in
+	 * the tce tables.
+	 */
+	if (order >= IOMAP_MAX_ORDER) {
+		printk("iommu_alloc_consistent size too large: 0x%lx\n", size);
+		return NULL;
+	}
+
+	if (!tbl)
+		return NULL;
+
+	/* Alloc enough pages (and possibly more) */
+	ret = (void *)__get_free_pages(flag, order);
+	if (!ret)
+		return NULL;
+	memset(ret, 0, size);
+
+	/* Set up tces to cover the allocated range */
+	mapping = iommu_alloc(tbl, ret, npages, DMA_BIDIRECTIONAL, order);
+	if (mapping == DMA_ERROR_CODE) {
+		free_pages((unsigned long)ret, order);
+		ret = NULL;
+	} else
+		*dma_handle = mapping;
+	return ret;
+}
+
+void iommu_free_coherent(struct iommu_table *tbl, size_t size,
+			 void *vaddr, dma_addr_t dma_handle)
+{
+	unsigned int npages;
+
+	if (tbl) {
+		size = PAGE_ALIGN(size);
+		npages = size >> PAGE_SHIFT;
+		iommu_free(tbl, dma_handle, npages);
+		free_pages((unsigned long)vaddr, get_order(size));
+	}
+}