Adding upstream version 5.10.209.upstream/5.10.209

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

1 files changed, 1089 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
new file mode 100644
index 000000000..d04079b34
--- /dev/null
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -0,0 +1,1089 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * IOMMU implementation for Cell Broadband Processor Architecture
+ *
+ * (C) Copyright IBM Corporation 2006-2008
+ *
+ * Author: Jeremy Kerr <jk@ozlabs.org>
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+#include <linux/memblock.h>
+
+#include <asm/prom.h>
+#include <asm/iommu.h>
+#include <asm/machdep.h>
+#include <asm/pci-bridge.h>
+#include <asm/udbg.h>
+#include <asm/firmware.h>
+#include <asm/cell-regs.h>
+
+#include "cell.h"
+#include "interrupt.h"
+
+/* Define CELL_IOMMU_REAL_UNMAP to actually unmap non-used pages
+ * instead of leaving them mapped to some dummy page. This can be
+ * enabled once the appropriate workarounds for spider bugs have
+ * been enabled
+ */
+#define CELL_IOMMU_REAL_UNMAP
+
+/* Define CELL_IOMMU_STRICT_PROTECTION to enforce protection of
+ * IO PTEs based on the transfer direction. That can be enabled
+ * once spider-net has been fixed to pass the correct direction
+ * to the DMA mapping functions
+ */
+#define CELL_IOMMU_STRICT_PROTECTION
+
+
+#define NR_IOMMUS			2
+
+/* IOC mmap registers */
+#define IOC_Reg_Size			0x2000
+
+#define IOC_IOPT_CacheInvd		0x908
+#define IOC_IOPT_CacheInvd_NE_Mask	0xffe0000000000000ul
+#define IOC_IOPT_CacheInvd_IOPTE_Mask	0x000003fffffffff8ul
+#define IOC_IOPT_CacheInvd_Busy		0x0000000000000001ul
+
+#define IOC_IOST_Origin			0x918
+#define IOC_IOST_Origin_E		0x8000000000000000ul
+#define IOC_IOST_Origin_HW		0x0000000000000800ul
+#define IOC_IOST_Origin_HL		0x0000000000000400ul
+
+#define IOC_IO_ExcpStat			0x920
+#define IOC_IO_ExcpStat_V		0x8000000000000000ul
+#define IOC_IO_ExcpStat_SPF_Mask	0x6000000000000000ul
+#define IOC_IO_ExcpStat_SPF_S		0x6000000000000000ul
+#define IOC_IO_ExcpStat_SPF_P		0x2000000000000000ul
+#define IOC_IO_ExcpStat_ADDR_Mask	0x00000007fffff000ul
+#define IOC_IO_ExcpStat_RW_Mask		0x0000000000000800ul
+#define IOC_IO_ExcpStat_IOID_Mask	0x00000000000007fful
+
+#define IOC_IO_ExcpMask			0x928
+#define IOC_IO_ExcpMask_SFE		0x4000000000000000ul
+#define IOC_IO_ExcpMask_PFE		0x2000000000000000ul
+
+#define IOC_IOCmd_Offset		0x1000
+
+#define IOC_IOCmd_Cfg			0xc00
+#define IOC_IOCmd_Cfg_TE		0x0000800000000000ul
+
+
+/* Segment table entries */
+#define IOSTE_V			0x8000000000000000ul /* valid */
+#define IOSTE_H			0x4000000000000000ul /* cache hint */
+#define IOSTE_PT_Base_RPN_Mask  0x3ffffffffffff000ul /* base RPN of IOPT */
+#define IOSTE_NPPT_Mask		0x0000000000000fe0ul /* no. pages in IOPT */
+#define IOSTE_PS_Mask		0x0000000000000007ul /* page size */
+#define IOSTE_PS_4K		0x0000000000000001ul /*   - 4kB  */
+#define IOSTE_PS_64K		0x0000000000000003ul /*   - 64kB */
+#define IOSTE_PS_1M		0x0000000000000005ul /*   - 1MB  */
+#define IOSTE_PS_16M		0x0000000000000007ul /*   - 16MB */
+
+
+/* IOMMU sizing */
+#define IO_SEGMENT_SHIFT	28
+#define IO_PAGENO_BITS(shift)	(IO_SEGMENT_SHIFT - (shift))
+
+/* The high bit needs to be set on every DMA address */
+#define SPIDER_DMA_OFFSET	0x80000000ul
+
+struct iommu_window {
+	struct list_head list;
+	struct cbe_iommu *iommu;
+	unsigned long offset;
+	unsigned long size;
+	unsigned int ioid;
+	struct iommu_table table;
+};
+
+#define NAMESIZE 8
+struct cbe_iommu {
+	int nid;
+	char name[NAMESIZE];
+	void __iomem *xlate_regs;
+	void __iomem *cmd_regs;
+	unsigned long *stab;
+	unsigned long *ptab;
+	void *pad_page;
+	struct list_head windows;
+};
+
+/* Static array of iommus, one per node
+ *   each contains a list of windows, keyed from dma_window property
+ *   - on bus setup, look for a matching window, or create one
+ *   - on dev setup, assign iommu_table ptr
+ */
+static struct cbe_iommu iommus[NR_IOMMUS];
+static int cbe_nr_iommus;
+
+static void invalidate_tce_cache(struct cbe_iommu *iommu, unsigned long *pte,
+		long n_ptes)
+{
+	u64 __iomem *reg;
+	u64 val;
+	long n;
+
+	reg = iommu->xlate_regs + IOC_IOPT_CacheInvd;
+
+	while (n_ptes > 0) {
+		/* we can invalidate up to 1 << 11 PTEs at once */
+		n = min(n_ptes, 1l << 11);
+		val = (((n /*- 1*/) << 53) & IOC_IOPT_CacheInvd_NE_Mask)
+			| (__pa(pte) & IOC_IOPT_CacheInvd_IOPTE_Mask)
+		        | IOC_IOPT_CacheInvd_Busy;
+
+		out_be64(reg, val);
+		while (in_be64(reg) & IOC_IOPT_CacheInvd_Busy)
+			;
+
+		n_ptes -= n;
+		pte += n;
+	}
+}
+
+static int tce_build_cell(struct iommu_table *tbl, long index, long npages,
+		unsigned long uaddr, enum dma_data_direction direction,
+		unsigned long attrs)
+{
+	int i;
+	unsigned long *io_pte, base_pte;
+	struct iommu_window *window =
+		container_of(tbl, struct iommu_window, table);
+
+	/* implementing proper protection causes problems with the spidernet
+	 * driver - check mapping directions later, but allow read & write by
+	 * default for now.*/
+#ifdef CELL_IOMMU_STRICT_PROTECTION
+	/* to avoid referencing a global, we use a trick here to setup the
+	 * protection bit. "prot" is setup to be 3 fields of 4 bits appended
+	 * together for each of the 3 supported direction values. It is then
+	 * shifted left so that the fields matching the desired direction
+	 * lands on the appropriate bits, and other bits are masked out.
+	 */
+	const unsigned long prot = 0xc48;
+	base_pte =
+		((prot << (52 + 4 * direction)) &
+		 (CBE_IOPTE_PP_W | CBE_IOPTE_PP_R)) |
+		CBE_IOPTE_M | CBE_IOPTE_SO_RW |
+		(window->ioid & CBE_IOPTE_IOID_Mask);
+#else
+	base_pte = CBE_IOPTE_PP_W | CBE_IOPTE_PP_R | CBE_IOPTE_M |
+		CBE_IOPTE_SO_RW | (window->ioid & CBE_IOPTE_IOID_Mask);
+#endif
+	if (unlikely(attrs & DMA_ATTR_WEAK_ORDERING))
+		base_pte &= ~CBE_IOPTE_SO_RW;
+
+	io_pte = (unsigned long *)tbl->it_base + (index - tbl->it_offset);
+
+	for (i = 0; i < npages; i++, uaddr += (1 << tbl->it_page_shift))
+		io_pte[i] = base_pte | (__pa(uaddr) & CBE_IOPTE_RPN_Mask);
+
+	mb();
+
+	invalidate_tce_cache(window->iommu, io_pte, npages);
+
+	pr_debug("tce_build_cell(index=%lx,n=%lx,dir=%d,base_pte=%lx)\n",
+		 index, npages, direction, base_pte);
+	return 0;
+}
+
+static void tce_free_cell(struct iommu_table *tbl, long index, long npages)
+{
+
+	int i;
+	unsigned long *io_pte, pte;
+	struct iommu_window *window =
+		container_of(tbl, struct iommu_window, table);
+
+	pr_debug("tce_free_cell(index=%lx,n=%lx)\n", index, npages);
+
+#ifdef CELL_IOMMU_REAL_UNMAP
+	pte = 0;
+#else
+	/* spider bridge does PCI reads after freeing - insert a mapping
+	 * to a scratch page instead of an invalid entry */
+	pte = CBE_IOPTE_PP_R | CBE_IOPTE_M | CBE_IOPTE_SO_RW |
+		__pa(window->iommu->pad_page) |
+		(window->ioid & CBE_IOPTE_IOID_Mask);
+#endif
+
+	io_pte = (unsigned long *)tbl->it_base + (index - tbl->it_offset);
+
+	for (i = 0; i < npages; i++)
+		io_pte[i] = pte;
+
+	mb();
+
+	invalidate_tce_cache(window->iommu, io_pte, npages);
+}
+
+static irqreturn_t ioc_interrupt(int irq, void *data)
+{
+	unsigned long stat, spf;
+	struct cbe_iommu *iommu = data;
+
+	stat = in_be64(iommu->xlate_regs + IOC_IO_ExcpStat);
+	spf = stat & IOC_IO_ExcpStat_SPF_Mask;
+
+	/* Might want to rate limit it */
+	printk(KERN_ERR "iommu: DMA exception 0x%016lx\n", stat);
+	printk(KERN_ERR "  V=%d, SPF=[%c%c], RW=%s, IOID=0x%04x\n",
+	       !!(stat & IOC_IO_ExcpStat_V),
+	       (spf == IOC_IO_ExcpStat_SPF_S) ? 'S' : ' ',
+	       (spf == IOC_IO_ExcpStat_SPF_P) ? 'P' : ' ',
+	       (stat & IOC_IO_ExcpStat_RW_Mask) ? "Read" : "Write",
+	       (unsigned int)(stat & IOC_IO_ExcpStat_IOID_Mask));
+	printk(KERN_ERR "  page=0x%016lx\n",
+	       stat & IOC_IO_ExcpStat_ADDR_Mask);
+
+	/* clear interrupt */
+	stat &= ~IOC_IO_ExcpStat_V;
+	out_be64(iommu->xlate_regs + IOC_IO_ExcpStat, stat);
+
+	return IRQ_HANDLED;
+}
+
+static int cell_iommu_find_ioc(int nid, unsigned long *base)
+{
+	struct device_node *np;
+	struct resource r;
+
+	*base = 0;
+
+	/* First look for new style /be nodes */
+	for_each_node_by_name(np, "ioc") {
+		if (of_node_to_nid(np) != nid)
+			continue;
+		if (of_address_to_resource(np, 0, &r)) {
+			printk(KERN_ERR "iommu: can't get address for %pOF\n",
+			       np);
+			continue;
+		}
+		*base = r.start;
+		of_node_put(np);
+		return 0;
+	}
+
+	/* Ok, let's try the old way */
+	for_each_node_by_type(np, "cpu") {
+		const unsigned int *nidp;
+		const unsigned long *tmp;
+
+		nidp = of_get_property(np, "node-id", NULL);
+		if (nidp && *nidp == nid) {
+			tmp = of_get_property(np, "ioc-translation", NULL);
+			if (tmp) {
+				*base = *tmp;
+				of_node_put(np);
+				return 0;
+			}
+		}
+	}
+
+	return -ENODEV;
+}
+
+static void cell_iommu_setup_stab(struct cbe_iommu *iommu,
+				unsigned long dbase, unsigned long dsize,
+				unsigned long fbase, unsigned long fsize)
+{
+	struct page *page;
+	unsigned long segments, stab_size;
+
+	segments = max(dbase + dsize, fbase + fsize) >> IO_SEGMENT_SHIFT;
+
+	pr_debug("%s: iommu[%d]: segments: %lu\n",
+			__func__, iommu->nid, segments);
+
+	/* set up the segment table */
+	stab_size = segments * sizeof(unsigned long);
+	page = alloc_pages_node(iommu->nid, GFP_KERNEL, get_order(stab_size));
+	BUG_ON(!page);
+	iommu->stab = page_address(page);
+	memset(iommu->stab, 0, stab_size);
+}
+
+static unsigned long *cell_iommu_alloc_ptab(struct cbe_iommu *iommu,
+		unsigned long base, unsigned long size, unsigned long gap_base,
+		unsigned long gap_size, unsigned long page_shift)
+{
+	struct page *page;
+	int i;
+	unsigned long reg, segments, pages_per_segment, ptab_size,
+		      n_pte_pages, start_seg, *ptab;
+
+	start_seg = base >> IO_SEGMENT_SHIFT;
+	segments  = size >> IO_SEGMENT_SHIFT;
+	pages_per_segment = 1ull << IO_PAGENO_BITS(page_shift);
+	/* PTEs for each segment must start on a 4K boundary */
+	pages_per_segment = max(pages_per_segment,
+				(1 << 12) / sizeof(unsigned long));
+
+	ptab_size = segments * pages_per_segment * sizeof(unsigned long);
+	pr_debug("%s: iommu[%d]: ptab_size: %lu, order: %d\n", __func__,
+			iommu->nid, ptab_size, get_order(ptab_size));
+	page = alloc_pages_node(iommu->nid, GFP_KERNEL, get_order(ptab_size));
+	BUG_ON(!page);
+
+	ptab = page_address(page);
+	memset(ptab, 0, ptab_size);
+
+	/* number of 4K pages needed for a page table */
+	n_pte_pages = (pages_per_segment * sizeof(unsigned long)) >> 12;
+
+	pr_debug("%s: iommu[%d]: stab at %p, ptab at %p, n_pte_pages: %lu\n",
+			__func__, iommu->nid, iommu->stab, ptab,
+			n_pte_pages);
+
+	/* initialise the STEs */
+	reg = IOSTE_V | ((n_pte_pages - 1) << 5);
+
+	switch (page_shift) {
+	case 12: reg |= IOSTE_PS_4K;  break;
+	case 16: reg |= IOSTE_PS_64K; break;
+	case 20: reg |= IOSTE_PS_1M;  break;
+	case 24: reg |= IOSTE_PS_16M; break;
+	default: BUG();
+	}
+
+	gap_base = gap_base >> IO_SEGMENT_SHIFT;
+	gap_size = gap_size >> IO_SEGMENT_SHIFT;
+
+	pr_debug("Setting up IOMMU stab:\n");
+	for (i = start_seg; i < (start_seg + segments); i++) {
+		if (i >= gap_base && i < (gap_base + gap_size)) {
+			pr_debug("\toverlap at %d, skipping\n", i);
+			continue;
+		}
+		iommu->stab[i] = reg | (__pa(ptab) + (n_pte_pages << 12) *
+					(i - start_seg));
+		pr_debug("\t[%d] 0x%016lx\n", i, iommu->stab[i]);
+	}
+
+	return ptab;
+}
+
+static void cell_iommu_enable_hardware(struct cbe_iommu *iommu)
+{
+	int ret;
+	unsigned long reg, xlate_base;
+	unsigned int virq;
+
+	if (cell_iommu_find_ioc(iommu->nid, &xlate_base))
+		panic("%s: missing IOC register mappings for node %d\n",
+		      __func__, iommu->nid);
+
+	iommu->xlate_regs = ioremap(xlate_base, IOC_Reg_Size);
+	iommu->cmd_regs = iommu->xlate_regs + IOC_IOCmd_Offset;
+
+	/* ensure that the STEs have updated */
+	mb();
+
+	/* setup interrupts for the iommu. */
+	reg = in_be64(iommu->xlate_regs + IOC_IO_ExcpStat);
+	out_be64(iommu->xlate_regs + IOC_IO_ExcpStat,
+			reg & ~IOC_IO_ExcpStat_V);
+	out_be64(iommu->xlate_regs + IOC_IO_ExcpMask,
+			IOC_IO_ExcpMask_PFE | IOC_IO_ExcpMask_SFE);
+
+	virq = irq_create_mapping(NULL,
+			IIC_IRQ_IOEX_ATI | (iommu->nid << IIC_IRQ_NODE_SHIFT));
+	BUG_ON(!virq);
+
+	ret = request_irq(virq, ioc_interrupt, 0, iommu->name, iommu);
+	BUG_ON(ret);
+
+	/* set the IOC segment table origin register (and turn on the iommu) */
+	reg = IOC_IOST_Origin_E | __pa(iommu->stab) | IOC_IOST_Origin_HW;
+	out_be64(iommu->xlate_regs + IOC_IOST_Origin, reg);
+	in_be64(iommu->xlate_regs + IOC_IOST_Origin);
+
+	/* turn on IO translation */
+	reg = in_be64(iommu->cmd_regs + IOC_IOCmd_Cfg) | IOC_IOCmd_Cfg_TE;
+	out_be64(iommu->cmd_regs + IOC_IOCmd_Cfg, reg);
+}
+
+static void cell_iommu_setup_hardware(struct cbe_iommu *iommu,
+	unsigned long base, unsigned long size)
+{
+	cell_iommu_setup_stab(iommu, base, size, 0, 0);
+	iommu->ptab = cell_iommu_alloc_ptab(iommu, base, size, 0, 0,
+					    IOMMU_PAGE_SHIFT_4K);
+	cell_iommu_enable_hardware(iommu);
+}
+
+#if 0/* Unused for now */
+static struct iommu_window *find_window(struct cbe_iommu *iommu,
+		unsigned long offset, unsigned long size)
+{
+	struct iommu_window *window;
+
+	/* todo: check for overlapping (but not equal) windows) */
+
+	list_for_each_entry(window, &(iommu->windows), list) {
+		if (window->offset == offset && window->size == size)
+			return window;
+	}
+
+	return NULL;
+}
+#endif
+
+static inline u32 cell_iommu_get_ioid(struct device_node *np)
+{
+	const u32 *ioid;
+
+	ioid = of_get_property(np, "ioid", NULL);
+	if (ioid == NULL) {
+		printk(KERN_WARNING "iommu: missing ioid for %pOF using 0\n",
+		       np);
+		return 0;
+	}
+
+	return *ioid;
+}
+
+static struct iommu_table_ops cell_iommu_ops = {
+	.set = tce_build_cell,
+	.clear = tce_free_cell
+};
+
+static struct iommu_window * __init
+cell_iommu_setup_window(struct cbe_iommu *iommu, struct device_node *np,
+			unsigned long offset, unsigned long size,
+			unsigned long pte_offset)
+{
+	struct iommu_window *window;
+	struct page *page;
+	u32 ioid;
+
+	ioid = cell_iommu_get_ioid(np);
+
+	window = kzalloc_node(sizeof(*window), GFP_KERNEL, iommu->nid);
+	BUG_ON(window == NULL);
+
+	window->offset = offset;
+	window->size = size;
+	window->ioid = ioid;
+	window->iommu = iommu;
+
+	window->table.it_blocksize = 16;
+	window->table.it_base = (unsigned long)iommu->ptab;
+	window->table.it_index = iommu->nid;
+	window->table.it_page_shift = IOMMU_PAGE_SHIFT_4K;
+	window->table.it_offset =
+		(offset >> window->table.it_page_shift) + pte_offset;
+	window->table.it_size = size >> window->table.it_page_shift;
+	window->table.it_ops = &cell_iommu_ops;
+
+	iommu_init_table(&window->table, iommu->nid, 0, 0);
+
+	pr_debug("\tioid      %d\n", window->ioid);
+	pr_debug("\tblocksize %ld\n", window->table.it_blocksize);
+	pr_debug("\tbase      0x%016lx\n", window->table.it_base);
+	pr_debug("\toffset    0x%lx\n", window->table.it_offset);
+	pr_debug("\tsize      %ld\n", window->table.it_size);
+
+	list_add(&window->list, &iommu->windows);
+
+	if (offset != 0)
+		return window;
+
+	/* We need to map and reserve the first IOMMU page since it's used
+	 * by the spider workaround. In theory, we only need to do that when
+	 * running on spider but it doesn't really matter.
+	 *
+	 * This code also assumes that we have a window that starts at 0,
+	 * which is the case on all spider based blades.
+	 */
+	page = alloc_pages_node(iommu->nid, GFP_KERNEL, 0);
+	BUG_ON(!page);
+	iommu->pad_page = page_address(page);
+	clear_page(iommu->pad_page);
+
+	__set_bit(0, window->table.it_map);
+	tce_build_cell(&window->table, window->table.it_offset, 1,
+		       (unsigned long)iommu->pad_page, DMA_TO_DEVICE, 0);
+
+	return window;
+}
+
+static struct cbe_iommu *cell_iommu_for_node(int nid)
+{
+	int i;
+
+	for (i = 0; i < cbe_nr_iommus; i++)
+		if (iommus[i].nid == nid)
+			return &iommus[i];
+	return NULL;
+}
+
+static unsigned long cell_dma_nommu_offset;
+
+static unsigned long dma_iommu_fixed_base;
+static bool cell_iommu_enabled;
+
+/* iommu_fixed_is_weak is set if booted with iommu_fixed=weak */
+bool iommu_fixed_is_weak;
+
+static struct iommu_table *cell_get_iommu_table(struct device *dev)
+{
+	struct iommu_window *window;
+	struct cbe_iommu *iommu;
+
+	/* Current implementation uses the first window available in that
+	 * node's iommu. We -might- do something smarter later though it may
+	 * never be necessary
+	 */
+	iommu = cell_iommu_for_node(dev_to_node(dev));
+	if (iommu == NULL || list_empty(&iommu->windows)) {
+		dev_err(dev, "iommu: missing iommu for %pOF (node %d)\n",
+		       dev->of_node, dev_to_node(dev));
+		return NULL;
+	}
+	window = list_entry(iommu->windows.next, struct iommu_window, list);
+
+	return &window->table;
+}
+
+static u64 cell_iommu_get_fixed_address(struct device *dev);
+
+static void cell_dma_dev_setup(struct device *dev)
+{
+	if (cell_iommu_enabled) {
+		u64 addr = cell_iommu_get_fixed_address(dev);
+
+		if (addr != OF_BAD_ADDR)
+			dev->archdata.dma_offset = addr + dma_iommu_fixed_base;
+		set_iommu_table_base(dev, cell_get_iommu_table(dev));
+	} else {
+		dev->archdata.dma_offset = cell_dma_nommu_offset;
+	}
+}
+
+static void cell_pci_dma_dev_setup(struct pci_dev *dev)
+{
+	cell_dma_dev_setup(&dev->dev);
+}
+
+static int cell_of_bus_notify(struct notifier_block *nb, unsigned long action,
+			      void *data)
+{
+	struct device *dev = data;
+
+	/* We are only intereted in device addition */
+	if (action != BUS_NOTIFY_ADD_DEVICE)
+		return 0;
+
+	if (cell_iommu_enabled)
+		dev->dma_ops = &dma_iommu_ops;
+	cell_dma_dev_setup(dev);
+	return 0;
+}
+
+static struct notifier_block cell_of_bus_notifier = {
+	.notifier_call = cell_of_bus_notify
+};
+
+static int __init cell_iommu_get_window(struct device_node *np,
+					 unsigned long *base,
+					 unsigned long *size)
+{
+	const __be32 *dma_window;
+	unsigned long index;
+
+	/* Use ibm,dma-window if available, else, hard code ! */
+	dma_window = of_get_property(np, "ibm,dma-window", NULL);
+	if (dma_window == NULL) {
+		*base = 0;
+		*size = 0x80000000u;
+		return -ENODEV;
+	}
+
+	of_parse_dma_window(np, dma_window, &index, base, size);
+	return 0;
+}
+
+static struct cbe_iommu * __init cell_iommu_alloc(struct device_node *np)
+{
+	struct cbe_iommu *iommu;
+	int nid, i;
+
+	/* Get node ID */
+	nid = of_node_to_nid(np);
+	if (nid < 0) {
+		printk(KERN_ERR "iommu: failed to get node for %pOF\n",
+		       np);
+		return NULL;
+	}
+	pr_debug("iommu: setting up iommu for node %d (%pOF)\n",
+		 nid, np);
+
+	/* XXX todo: If we can have multiple windows on the same IOMMU, which
+	 * isn't the case today, we probably want here to check whether the
+	 * iommu for that node is already setup.
+	 * However, there might be issue with getting the size right so let's
+	 * ignore that for now. We might want to completely get rid of the
+	 * multiple window support since the cell iommu supports per-page ioids
+	 */
+
+	if (cbe_nr_iommus >= NR_IOMMUS) {
+		printk(KERN_ERR "iommu: too many IOMMUs detected ! (%pOF)\n",
+		       np);
+		return NULL;
+	}
+
+	/* Init base fields */
+	i = cbe_nr_iommus++;
+	iommu = &iommus[i];
+	iommu->stab = NULL;
+	iommu->nid = nid;
+	snprintf(iommu->name, sizeof(iommu->name), "iommu%d", i);
+	INIT_LIST_HEAD(&iommu->windows);
+
+	return iommu;
+}
+
+static void __init cell_iommu_init_one(struct device_node *np,
+				       unsigned long offset)
+{
+	struct cbe_iommu *iommu;
+	unsigned long base, size;
+
+	iommu = cell_iommu_alloc(np);
+	if (!iommu)
+		return;
+
+	/* Obtain a window for it */
+	cell_iommu_get_window(np, &base, &size);
+
+	pr_debug("\ttranslating window 0x%lx...0x%lx\n",
+		 base, base + size - 1);
+
+	/* Initialize the hardware */
+	cell_iommu_setup_hardware(iommu, base, size);
+
+	/* Setup the iommu_table */
+	cell_iommu_setup_window(iommu, np, base, size,
+				offset >> IOMMU_PAGE_SHIFT_4K);
+}
+
+static void __init cell_disable_iommus(void)
+{
+	int node;
+	unsigned long base, val;
+	void __iomem *xregs, *cregs;
+
+	/* Make sure IOC translation is disabled on all nodes */
+	for_each_online_node(node) {
+		if (cell_iommu_find_ioc(node, &base))
+			continue;
+		xregs = ioremap(base, IOC_Reg_Size);
+		if (xregs == NULL)
+			continue;
+		cregs = xregs + IOC_IOCmd_Offset;
+
+		pr_debug("iommu: cleaning up iommu on node %d\n", node);
+
+		out_be64(xregs + IOC_IOST_Origin, 0);
+		(void)in_be64(xregs + IOC_IOST_Origin);
+		val = in_be64(cregs + IOC_IOCmd_Cfg);
+		val &= ~IOC_IOCmd_Cfg_TE;
+		out_be64(cregs + IOC_IOCmd_Cfg, val);
+		(void)in_be64(cregs + IOC_IOCmd_Cfg);
+
+		iounmap(xregs);
+	}
+}
+
+static int __init cell_iommu_init_disabled(void)
+{
+	struct device_node *np = NULL;
+	unsigned long base = 0, size;
+
+	/* When no iommu is present, we use direct DMA ops */
+
+	/* First make sure all IOC translation is turned off */
+	cell_disable_iommus();
+
+	/* If we have no Axon, we set up the spider DMA magic offset */
+	if (of_find_node_by_name(NULL, "axon") == NULL)
+		cell_dma_nommu_offset = SPIDER_DMA_OFFSET;
+
+	/* Now we need to check to see where the memory is mapped
+	 * in PCI space. We assume that all busses use the same dma
+	 * window which is always the case so far on Cell, thus we
+	 * pick up the first pci-internal node we can find and check
+	 * the DMA window from there.
+	 */
+	for_each_node_by_name(np, "axon") {
+		if (np->parent == NULL || np->parent->parent != NULL)
+			continue;
+		if (cell_iommu_get_window(np, &base, &size) == 0)
+			break;
+	}
+	if (np == NULL) {
+		for_each_node_by_name(np, "pci-internal") {
+			if (np->parent == NULL || np->parent->parent != NULL)
+				continue;
+			if (cell_iommu_get_window(np, &base, &size) == 0)
+				break;
+		}
+	}
+	of_node_put(np);
+
+	/* If we found a DMA window, we check if it's big enough to enclose
+	 * all of physical memory. If not, we force enable IOMMU
+	 */
+	if (np && size < memblock_end_of_DRAM()) {
+		printk(KERN_WARNING "iommu: force-enabled, dma window"
+		       " (%ldMB) smaller than total memory (%lldMB)\n",
+		       size >> 20, memblock_end_of_DRAM() >> 20);
+		return -ENODEV;
+	}
+
+	cell_dma_nommu_offset += base;
+
+	if (cell_dma_nommu_offset != 0)
+		cell_pci_controller_ops.dma_dev_setup = cell_pci_dma_dev_setup;
+
+	printk("iommu: disabled, direct DMA offset is 0x%lx\n",
+	       cell_dma_nommu_offset);
+
+	return 0;
+}
+
+/*
+ *  Fixed IOMMU mapping support
+ *
+ *  This code adds support for setting up a fixed IOMMU mapping on certain
+ *  cell machines. For 64-bit devices this avoids the performance overhead of
+ *  mapping and unmapping pages at runtime. 32-bit devices are unable to use
+ *  the fixed mapping.
+ *
+ *  The fixed mapping is established at boot, and maps all of physical memory
+ *  1:1 into device space at some offset. On machines with < 30 GB of memory
+ *  we setup the fixed mapping immediately above the normal IOMMU window.
+ *
+ *  For example a machine with 4GB of memory would end up with the normal
+ *  IOMMU window from 0-2GB and the fixed mapping window from 2GB to 6GB. In
+ *  this case a 64-bit device wishing to DMA to 1GB would be told to DMA to
+ *  3GB, plus any offset required by firmware. The firmware offset is encoded
+ *  in the "dma-ranges" property.
+ *
+ *  On machines with 30GB or more of memory, we are unable to place the fixed
+ *  mapping above the normal IOMMU window as we would run out of address space.
+ *  Instead we move the normal IOMMU window to coincide with the hash page
+ *  table, this region does not need to be part of the fixed mapping as no
+ *  device should ever be DMA'ing to it. We then setup the fixed mapping
+ *  from 0 to 32GB.
+ */
+
+static u64 cell_iommu_get_fixed_address(struct device *dev)
+{
+	u64 cpu_addr, size, best_size, dev_addr = OF_BAD_ADDR;
+	struct device_node *np;
+	const u32 *ranges = NULL;
+	int i, len, best, naddr, nsize, pna, range_size;
+
+	/* We can be called for platform devices that have no of_node */
+	np = of_node_get(dev->of_node);
+	if (!np)
+		goto out;
+
+	while (1) {
+		naddr = of_n_addr_cells(np);
+		nsize = of_n_size_cells(np);
+		np = of_get_next_parent(np);
+		if (!np)
+			break;
+
+		ranges = of_get_property(np, "dma-ranges", &len);
+
+		/* Ignore empty ranges, they imply no translation required */
+		if (ranges && len > 0)
+			break;
+	}
+
+	if (!ranges) {
+		dev_dbg(dev, "iommu: no dma-ranges found\n");
+		goto out;
+	}
+
+	len /= sizeof(u32);
+
+	pna = of_n_addr_cells(np);
+	range_size = naddr + nsize + pna;
+
+	/* dma-ranges format:
+	 * child addr	: naddr cells
+	 * parent addr	: pna cells
+	 * size		: nsize cells
+	 */
+	for (i = 0, best = -1, best_size = 0; i < len; i += range_size) {
+		cpu_addr = of_translate_dma_address(np, ranges + i + naddr);
+		size = of_read_number(ranges + i + naddr + pna, nsize);
+
+		if (cpu_addr == 0 && size > best_size) {
+			best = i;
+			best_size = size;
+		}
+	}
+
+	if (best >= 0) {
+		dev_addr = of_read_number(ranges + best, naddr);
+	} else
+		dev_dbg(dev, "iommu: no suitable range found!\n");
+
+out:
+	of_node_put(np);
+
+	return dev_addr;
+}
+
+static bool cell_pci_iommu_bypass_supported(struct pci_dev *pdev, u64 mask)
+{
+	return mask == DMA_BIT_MASK(64) &&
+		cell_iommu_get_fixed_address(&pdev->dev) != OF_BAD_ADDR;
+}
+
+static void insert_16M_pte(unsigned long addr, unsigned long *ptab,
+			   unsigned long base_pte)
+{
+	unsigned long segment, offset;
+
+	segment = addr >> IO_SEGMENT_SHIFT;
+	offset = (addr >> 24) - (segment << IO_PAGENO_BITS(24));
+	ptab = ptab + (segment * (1 << 12) / sizeof(unsigned long));
+
+	pr_debug("iommu: addr %lx ptab %p segment %lx offset %lx\n",
+		  addr, ptab, segment, offset);
+
+	ptab[offset] = base_pte | (__pa(addr) & CBE_IOPTE_RPN_Mask);
+}
+
+static void cell_iommu_setup_fixed_ptab(struct cbe_iommu *iommu,
+	struct device_node *np, unsigned long dbase, unsigned long dsize,
+	unsigned long fbase, unsigned long fsize)
+{
+	unsigned long base_pte, uaddr, ioaddr, *ptab;
+
+	ptab = cell_iommu_alloc_ptab(iommu, fbase, fsize, dbase, dsize, 24);
+
+	dma_iommu_fixed_base = fbase;
+
+	pr_debug("iommu: mapping 0x%lx pages from 0x%lx\n", fsize, fbase);
+
+	base_pte = CBE_IOPTE_PP_W | CBE_IOPTE_PP_R | CBE_IOPTE_M |
+		(cell_iommu_get_ioid(np) & CBE_IOPTE_IOID_Mask);
+
+	if (iommu_fixed_is_weak)
+		pr_info("IOMMU: Using weak ordering for fixed mapping\n");
+	else {
+		pr_info("IOMMU: Using strong ordering for fixed mapping\n");
+		base_pte |= CBE_IOPTE_SO_RW;
+	}
+
+	for (uaddr = 0; uaddr < fsize; uaddr += (1 << 24)) {
+		/* Don't touch the dynamic region */
+		ioaddr = uaddr + fbase;
+		if (ioaddr >= dbase && ioaddr < (dbase + dsize)) {
+			pr_debug("iommu: fixed/dynamic overlap, skipping\n");
+			continue;
+		}
+
+		insert_16M_pte(uaddr, ptab, base_pte);
+	}
+
+	mb();
+}
+
+static int __init cell_iommu_fixed_mapping_init(void)
+{
+	unsigned long dbase, dsize, fbase, fsize, hbase, hend;
+	struct cbe_iommu *iommu;
+	struct device_node *np;
+
+	/* The fixed mapping is only supported on axon machines */
+	np = of_find_node_by_name(NULL, "axon");
+	of_node_put(np);
+
+	if (!np) {
+		pr_debug("iommu: fixed mapping disabled, no axons found\n");
+		return -1;
+	}
+
+	/* We must have dma-ranges properties for fixed mapping to work */
+	np = of_find_node_with_property(NULL, "dma-ranges");
+	of_node_put(np);
+
+	if (!np) {
+		pr_debug("iommu: no dma-ranges found, no fixed mapping\n");
+		return -1;
+	}
+
+	/* The default setup is to have the fixed mapping sit after the
+	 * dynamic region, so find the top of the largest IOMMU window
+	 * on any axon, then add the size of RAM and that's our max value.
+	 * If that is > 32GB we have to do other shennanigans.
+	 */
+	fbase = 0;
+	for_each_node_by_name(np, "axon") {
+		cell_iommu_get_window(np, &dbase, &dsize);
+		fbase = max(fbase, dbase + dsize);
+	}
+
+	fbase = ALIGN(fbase, 1 << IO_SEGMENT_SHIFT);
+	fsize = memblock_phys_mem_size();
+
+	if ((fbase + fsize) <= 0x800000000ul)
+		hbase = 0; /* use the device tree window */
+	else {
+		/* If we're over 32 GB we need to cheat. We can't map all of
+		 * RAM with the fixed mapping, and also fit the dynamic
+		 * region. So try to place the dynamic region where the hash
+		 * table sits, drivers never need to DMA to it, we don't
+		 * need a fixed mapping for that area.
+		 */
+		if (!htab_address) {
+			pr_debug("iommu: htab is NULL, on LPAR? Huh?\n");
+			return -1;
+		}
+		hbase = __pa(htab_address);
+		hend  = hbase + htab_size_bytes;
+
+		/* The window must start and end on a segment boundary */
+		if ((hbase != ALIGN(hbase, 1 << IO_SEGMENT_SHIFT)) ||
+		    (hend != ALIGN(hend, 1 << IO_SEGMENT_SHIFT))) {
+			pr_debug("iommu: hash window not segment aligned\n");
+			return -1;
+		}
+
+		/* Check the hash window fits inside the real DMA window */
+		for_each_node_by_name(np, "axon") {
+			cell_iommu_get_window(np, &dbase, &dsize);
+
+			if (hbase < dbase || (hend > (dbase + dsize))) {
+				pr_debug("iommu: hash window doesn't fit in"
+					 "real DMA window\n");
+				of_node_put(np);
+				return -1;
+			}
+		}
+
+		fbase = 0;
+	}
+
+	/* Setup the dynamic regions */
+	for_each_node_by_name(np, "axon") {
+		iommu = cell_iommu_alloc(np);
+		BUG_ON(!iommu);
+
+		if (hbase == 0)
+			cell_iommu_get_window(np, &dbase, &dsize);
+		else {
+			dbase = hbase;
+			dsize = htab_size_bytes;
+		}
+
+		printk(KERN_DEBUG "iommu: node %d, dynamic window 0x%lx-0x%lx "
+			"fixed window 0x%lx-0x%lx\n", iommu->nid, dbase,
+			 dbase + dsize, fbase, fbase + fsize);
+
+		cell_iommu_setup_stab(iommu, dbase, dsize, fbase, fsize);
+		iommu->ptab = cell_iommu_alloc_ptab(iommu, dbase, dsize, 0, 0,
+						    IOMMU_PAGE_SHIFT_4K);
+		cell_iommu_setup_fixed_ptab(iommu, np, dbase, dsize,
+					     fbase, fsize);
+		cell_iommu_enable_hardware(iommu);
+		cell_iommu_setup_window(iommu, np, dbase, dsize, 0);
+	}
+
+	cell_pci_controller_ops.iommu_bypass_supported =
+		cell_pci_iommu_bypass_supported;
+	return 0;
+}
+
+static int iommu_fixed_disabled;
+
+static int __init setup_iommu_fixed(char *str)
+{
+	struct device_node *pciep;
+
+	if (strcmp(str, "off") == 0)
+		iommu_fixed_disabled = 1;
+
+	/* If we can find a pcie-endpoint in the device tree assume that
+	 * we're on a triblade or a CAB so by default the fixed mapping
+	 * should be set to be weakly ordered; but only if the boot
+	 * option WASN'T set for strong ordering
+	 */
+	pciep = of_find_node_by_type(NULL, "pcie-endpoint");
+
+	if (strcmp(str, "weak") == 0 || (pciep && strcmp(str, "strong") != 0))
+		iommu_fixed_is_weak = true;
+
+	of_node_put(pciep);
+
+	return 1;
+}
+__setup("iommu_fixed=", setup_iommu_fixed);
+
+static int __init cell_iommu_init(void)
+{
+	struct device_node *np;
+
+	/* If IOMMU is disabled or we have little enough RAM to not need
+	 * to enable it, we setup a direct mapping.
+	 *
+	 * Note: should we make sure we have the IOMMU actually disabled ?
+	 */
+	if (iommu_is_off ||
+	    (!iommu_force_on && memblock_end_of_DRAM() <= 0x80000000ull))
+		if (cell_iommu_init_disabled() == 0)
+			goto bail;
+
+	/* Setup various callbacks */
+	cell_pci_controller_ops.dma_dev_setup = cell_pci_dma_dev_setup;
+
+	if (!iommu_fixed_disabled && cell_iommu_fixed_mapping_init() == 0)
+		goto done;
+
+	/* Create an iommu for each /axon node.  */
+	for_each_node_by_name(np, "axon") {
+		if (np->parent == NULL || np->parent->parent != NULL)
+			continue;
+		cell_iommu_init_one(np, 0);
+	}
+
+	/* Create an iommu for each toplevel /pci-internal node for
+	 * old hardware/firmware
+	 */
+	for_each_node_by_name(np, "pci-internal") {
+		if (np->parent == NULL || np->parent->parent != NULL)
+			continue;
+		cell_iommu_init_one(np, SPIDER_DMA_OFFSET);
+	}
+ done:
+	/* Setup default PCI iommu ops */
+	set_pci_dma_ops(&dma_iommu_ops);
+	cell_iommu_enabled = true;
+ bail:
+	/* Register callbacks on OF platform device addition/removal
+	 * to handle linking them to the right DMA operations
+	 */
+	bus_register_notifier(&platform_bus_type, &cell_of_bus_notifier);
+
+	return 0;
+}
+machine_arch_initcall(cell, cell_iommu_init);