msm: Add MSM IOMMU support

Add support for the IOMMUs found on the upcoming Qualcomm
MSM8x60 chips. These IOMMUs allow virtualization of the
address space used by most of the multimedia cores on these
chips.
Signed-off-by: NStepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: NDaniel Walker <dwalker@codeaurora.org>

arch/arm/mach-msm/include/mach/iommu.h

+/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef MSM_IOMMU_H
+#define MSM_IOMMU_H
+
+#include <linux/interrupt.h>
+
+/* Maximum number of Machine IDs that we are allowing to be mapped to the same
+ * context bank. The number of MIDs mapped to the same CB does not affect
+ * performance, but there is a practical limit on how many distinct MIDs may
+ * be present. These mappings are typically determined at design time and are
+ * not expected to change at run time.
+ */
+#define MAX_NUM_MIDS	16
+
+/**
+ * struct msm_iommu_dev - a single IOMMU hardware instance
+ * name		Human-readable name given to this IOMMU HW instance
+ * clk_rate	Rate to set for this IOMMU's clock, if applicable to this
+ *		particular IOMMU. 0 means don't set a rate.
+ *		-1 means it is an AXI clock with no valid rate
+ *
+ */
+struct msm_iommu_dev {
+	const char *name;
+	int clk_rate;
+};
+
+/**
+ * struct msm_iommu_ctx_dev - an IOMMU context bank instance
+ * name		Human-readable name given to this context bank
+ * num		Index of this context bank within the hardware
+ * mids		List of Machine IDs that are to be mapped into this context
+ *		bank, terminated by -1. The MID is a set of signals on the
+ *		AXI bus that identifies the function associated with a specific
+ *		memory request. (See ARM spec).
+ */
+struct msm_iommu_ctx_dev {
+	const char *name;
+	int num;
+	int mids[MAX_NUM_MIDS];
+};
+
+
+/**
+ * struct msm_iommu_drvdata - A single IOMMU hardware instance
+ * @base:	IOMMU config port base address (VA)
+ * @irq:	Interrupt number
+  *
+ * A msm_iommu_drvdata holds the global driver data about a single piece
+ * of an IOMMU hardware instance.
+ */
+struct msm_iommu_drvdata {
+	void __iomem *base;
+	int irq;
+};
+
+/**
+ * struct msm_iommu_ctx_drvdata - an IOMMU context bank instance
+ * @num:		Hardware context number of this context
+ * @pdev:		Platform device associated wit this HW instance
+ * @attached_elm:	List element for domains to track which devices are
+ *			attached to them
+ *
+ * A msm_iommu_ctx_drvdata holds the driver data for a single context bank
+ * within each IOMMU hardware instance
+ */
+struct msm_iommu_ctx_drvdata {
+	int num;
+	struct platform_device *pdev;
+	struct list_head attached_elm;
+};
+
+/*
+ * Look up an IOMMU context device by its context name. NULL if none found.
+ * Useful for testing and drivers that do not yet fully have IOMMU stuff in
+ * their platform devices.
+ */
+struct device *msm_iommu_get_ctx(const char *ctx_name);
+
+/*
+ * Interrupt handler for the IOMMU context fault interrupt. Hooking the
+ * interrupt is not supported in the API yet, but this will print an error
+ * message and dump useful IOMMU registers.
+ */
+irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id);
+
+#endif

arch/arm/mach-msm/iommu.c

+/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/iommu.h>
+
+#include <asm/cacheflush.h>
+#include <asm/sizes.h>
+
+#include <mach/iommu_hw-8xxx.h>
+#include <mach/iommu.h>
+
+DEFINE_SPINLOCK(msm_iommu_lock);
+
+struct msm_priv {
+	unsigned long *pgtable;
+	struct list_head list_attached;
+};
+
+static void __flush_iotlb(struct iommu_domain *domain)
+{
+	struct msm_priv *priv = domain->priv;
+	struct msm_iommu_drvdata *iommu_drvdata;
+	struct msm_iommu_ctx_drvdata *ctx_drvdata;
+
+#ifndef CONFIG_IOMMU_PGTABLES_L2
+	unsigned long *fl_table = priv->pgtable;
+	int i;
+
+	dmac_flush_range(fl_table, fl_table + SZ_16K);
+
+	for (i = 0; i < NUM_FL_PTE; i++)
+		if ((fl_table[i] & 0x03) == FL_TYPE_TABLE) {
+			void *sl_table = __va(fl_table[i] & FL_BASE_MASK);
+			dmac_flush_range(sl_table, sl_table + SZ_4K);
+		}
+#endif
+
+	list_for_each_entry(ctx_drvdata, &priv->list_attached, attached_elm) {
+		if (!ctx_drvdata->pdev || !ctx_drvdata->pdev->dev.parent)
+			BUG();
+
+		iommu_drvdata = dev_get_drvdata(ctx_drvdata->pdev->dev.parent);
+		SET_CTX_TLBIALL(iommu_drvdata->base, ctx_drvdata->num, 0);
+	}
+}
+
+static void __reset_context(void __iomem *base, int ctx)
+{
+	SET_BPRCOSH(base, ctx, 0);
+	SET_BPRCISH(base, ctx, 0);
+	SET_BPRCNSH(base, ctx, 0);
+	SET_BPSHCFG(base, ctx, 0);
+	SET_BPMTCFG(base, ctx, 0);
+	SET_ACTLR(base, ctx, 0);
+	SET_SCTLR(base, ctx, 0);
+	SET_FSRRESTORE(base, ctx, 0);
+	SET_TTBR0(base, ctx, 0);
+	SET_TTBR1(base, ctx, 0);
+	SET_TTBCR(base, ctx, 0);
+	SET_BFBCR(base, ctx, 0);
+	SET_PAR(base, ctx, 0);
+	SET_FAR(base, ctx, 0);
+	SET_CTX_TLBIALL(base, ctx, 0);
+	SET_TLBFLPTER(base, ctx, 0);
+	SET_TLBSLPTER(base, ctx, 0);
+	SET_TLBLKCR(base, ctx, 0);
+	SET_PRRR(base, ctx, 0);
+	SET_NMRR(base, ctx, 0);
+	SET_CONTEXTIDR(base, ctx, 0);
+}
+
+static void __program_context(void __iomem *base, int ctx, phys_addr_t pgtable)
+{
+	__reset_context(base, ctx);
+
+	/* Set up HTW mode */
+	/* TLB miss configuration: perform HTW on miss */
+	SET_TLBMCFG(base, ctx, 0x3);
+
+	/* V2P configuration: HTW for access */
+	SET_V2PCFG(base, ctx, 0x3);
+
+	SET_TTBCR(base, ctx, 0);
+	SET_TTBR0_PA(base, ctx, (pgtable >> 14));
+
+	/* Invalidate the TLB for this context */
+	SET_CTX_TLBIALL(base, ctx, 0);
+
+	/* Set interrupt number to "secure" interrupt */
+	SET_IRPTNDX(base, ctx, 0);
+
+	/* Enable context fault interrupt */
+	SET_CFEIE(base, ctx, 1);
+
+	/* Stall access on a context fault and let the handler deal with it */
+	SET_CFCFG(base, ctx, 1);
+
+	/* Redirect all cacheable requests to L2 slave port. */
+	SET_RCISH(base, ctx, 1);
+	SET_RCOSH(base, ctx, 1);
+	SET_RCNSH(base, ctx, 1);
+
+	/* Turn on TEX Remap */
+	SET_TRE(base, ctx, 1);
+
+	/* Do not configure PRRR / NMRR on the IOMMU for now. We will assume
+	 * TEX class 0 for everything until attributes are properly worked out
+	 */
+	SET_PRRR(base, ctx, 0);
+	SET_NMRR(base, ctx, 0);
+
+	/* Turn on BFB prefetch */
+	SET_BFBDFE(base, ctx, 1);
+
+#ifdef CONFIG_IOMMU_PGTABLES_L2
+	/* Configure page tables as inner-cacheable and shareable to reduce
+	 * the TLB miss penalty.
+	 */
+	SET_TTBR0_SH(base, ctx, 1);
+	SET_TTBR1_SH(base, ctx, 1);
+
+	SET_TTBR0_NOS(base, ctx, 1);
+	SET_TTBR1_NOS(base, ctx, 1);
+
+	SET_TTBR0_IRGNH(base, ctx, 0); /* WB, WA */
+	SET_TTBR0_IRGNL(base, ctx, 1);
+
+	SET_TTBR1_IRGNH(base, ctx, 0); /* WB, WA */
+	SET_TTBR1_IRGNL(base, ctx, 1);
+
+	SET_TTBR0_ORGN(base, ctx, 1); /* WB, WA */
+	SET_TTBR1_ORGN(base, ctx, 1); /* WB, WA */
+#endif
+
+	/* Enable the MMU */
+	SET_M(base, ctx, 1);
+}
+
+static int msm_iommu_domain_init(struct iommu_domain *domain)
+{
+	struct msm_priv *priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+
+	if (!priv)
+		goto fail_nomem;
+
+	INIT_LIST_HEAD(&priv->list_attached);
+	priv->pgtable = (unsigned long *)__get_free_pages(GFP_KERNEL,
+							  get_order(SZ_16K));
+
+	if (!priv->pgtable)
+		goto fail_nomem;
+
+	memset(priv->pgtable, 0, SZ_16K);
+	domain->priv = priv;
+	return 0;
+
+fail_nomem:
+	kfree(priv);
+	return -ENOMEM;
+}
+
+static void msm_iommu_domain_destroy(struct iommu_domain *domain)
+{
+	struct msm_priv *priv;
+	unsigned long flags;
+	unsigned long *fl_table;
+	int i;
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+	priv = domain->priv;
+	domain->priv = NULL;
+
+	if (priv) {
+		fl_table = priv->pgtable;
+
+		for (i = 0; i < NUM_FL_PTE; i++)
+			if ((fl_table[i] & 0x03) == FL_TYPE_TABLE)
+				free_page((unsigned long) __va(((fl_table[i]) &
+								FL_BASE_MASK)));
+
+		free_pages((unsigned long)priv->pgtable, get_order(SZ_16K));
+		priv->pgtable = NULL;
+	}
+
+	kfree(priv);
+	spin_unlock_irqrestore(&msm_iommu_lock, flags);
+}
+
+static int msm_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
+{
+	struct msm_priv *priv;
+	struct msm_iommu_ctx_dev *ctx_dev;
+	struct msm_iommu_drvdata *iommu_drvdata;
+	struct msm_iommu_ctx_drvdata *ctx_drvdata;
+	struct msm_iommu_ctx_drvdata *tmp_drvdata;
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+
+	priv = domain->priv;
+
+	if (!priv || !dev) {
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	iommu_drvdata = dev_get_drvdata(dev->parent);
+	ctx_drvdata = dev_get_drvdata(dev);
+	ctx_dev = dev->platform_data;
+
+	if (!iommu_drvdata || !ctx_drvdata || !ctx_dev) {
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	list_for_each_entry(tmp_drvdata, &priv->list_attached, attached_elm)
+		if (tmp_drvdata == ctx_drvdata) {
+			ret = -EBUSY;
+			goto fail;
+		}
+
+	__program_context(iommu_drvdata->base, ctx_dev->num,
+			  __pa(priv->pgtable));
+
+	list_add(&(ctx_drvdata->attached_elm), &priv->list_attached);
+	__flush_iotlb(domain);
+
+fail:
+	spin_unlock_irqrestore(&msm_iommu_lock, flags);
+	return ret;
+}
+
+static void msm_iommu_detach_dev(struct iommu_domain *domain,
+				 struct device *dev)
+{
+	struct msm_priv *priv;
+	struct msm_iommu_ctx_dev *ctx_dev;
+	struct msm_iommu_drvdata *iommu_drvdata;
+	struct msm_iommu_ctx_drvdata *ctx_drvdata;
+	unsigned long flags;
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+	priv = domain->priv;
+
+	if (!priv || !dev)
+		goto fail;
+
+	iommu_drvdata = dev_get_drvdata(dev->parent);
+	ctx_drvdata = dev_get_drvdata(dev);
+	ctx_dev = dev->platform_data;
+
+	if (!iommu_drvdata || !ctx_drvdata || !ctx_dev)
+		goto fail;
+
+	__flush_iotlb(domain);
+	__reset_context(iommu_drvdata->base, ctx_dev->num);
+	list_del_init(&ctx_drvdata->attached_elm);
+
+fail:
+	spin_unlock_irqrestore(&msm_iommu_lock, flags);
+}
+
+static int msm_iommu_map(struct iommu_domain *domain, unsigned long va,
+			 phys_addr_t pa, int order, int prot)
+{
+	struct msm_priv *priv;
+	unsigned long flags;
+	unsigned long *fl_table;
+	unsigned long *fl_pte;
+	unsigned long fl_offset;
+	unsigned long *sl_table;
+	unsigned long *sl_pte;
+	unsigned long sl_offset;
+	size_t len = 0x1000UL << order;
+	int ret = 0;
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+	priv = domain->priv;
+
+	if (!priv) {
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	fl_table = priv->pgtable;
+
+	if (len != SZ_16M && len != SZ_1M &&
+	    len != SZ_64K && len != SZ_4K) {
+		pr_debug("Bad size: %d\n", len);
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	if (!fl_table) {
+		pr_debug("Null page table\n");
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	fl_offset = FL_OFFSET(va);	/* Upper 12 bits */
+	fl_pte = fl_table + fl_offset;	/* int pointers, 4 bytes */
+
+	if (len == SZ_16M) {
+		int i = 0;
+		for (i = 0; i < 16; i++)
+			*(fl_pte+i) = (pa & 0xFF000000) | FL_SUPERSECTION |
+				  FL_AP_READ | FL_AP_WRITE | FL_TYPE_SECT |
+				  FL_SHARED;
+	}
+
+	if (len == SZ_1M)
+		*fl_pte = (pa & 0xFFF00000) | FL_AP_READ | FL_AP_WRITE |
+						FL_TYPE_SECT | FL_SHARED;
+
+	/* Need a 2nd level table */
+	if ((len == SZ_4K || len == SZ_64K) && (*fl_pte) == 0) {
+		unsigned long *sl;
+		sl = (unsigned long *) __get_free_pages(GFP_KERNEL,
+							get_order(SZ_4K));
+
+		if (!sl) {
+			pr_debug("Could not allocate second level table\n");
+			ret = -ENOMEM;
+			goto fail;
+		}
+
+		memset(sl, 0, SZ_4K);
+		*fl_pte = ((((int)__pa(sl)) & FL_BASE_MASK) | FL_TYPE_TABLE);
+	}
+
+	sl_table = (unsigned long *) __va(((*fl_pte) & FL_BASE_MASK));
+	sl_offset = SL_OFFSET(va);
+	sl_pte = sl_table + sl_offset;
+
+
+	if (len == SZ_4K)
+		*sl_pte = (pa & SL_BASE_MASK_SMALL) | SL_AP0 | SL_AP1 |
+					  SL_SHARED | SL_TYPE_SMALL;
+
+	if (len == SZ_64K) {
+		int i;
+
+		for (i = 0; i < 16; i++)
+			*(sl_pte+i) = (pa & SL_BASE_MASK_LARGE) | SL_AP0 |
+					    SL_AP1 | SL_SHARED | SL_TYPE_LARGE;
+	}
+
+	__flush_iotlb(domain);
+fail:
+	spin_unlock_irqrestore(&msm_iommu_lock, flags);
+	return ret;
+}
+
+static int msm_iommu_unmap(struct iommu_domain *domain, unsigned long va,
+			    int order)
+{
+	struct msm_priv *priv;
+	unsigned long flags;
+	unsigned long *fl_table;
+	unsigned long *fl_pte;
+	unsigned long fl_offset;
+	unsigned long *sl_table;
+	unsigned long *sl_pte;
+	unsigned long sl_offset;
+	size_t len = 0x1000UL << order;
+	int i, ret = 0;
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+
+	priv = domain->priv;
+
+	if (!priv) {
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	fl_table = priv->pgtable;
+
+	if (len != SZ_16M && len != SZ_1M &&
+	    len != SZ_64K && len != SZ_4K) {
+		pr_debug("Bad length: %d\n", len);
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	if (!fl_table) {
+		pr_debug("Null page table\n");
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	fl_offset = FL_OFFSET(va);	/* Upper 12 bits */
+	fl_pte = fl_table + fl_offset;	/* int pointers, 4 bytes */
+
+	if (*fl_pte == 0) {
+		pr_debug("First level PTE is 0\n");
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	/* Unmap supersection */
+	if (len == SZ_16M)
+		for (i = 0; i < 16; i++)
+			*(fl_pte+i) = 0;
+
+	if (len == SZ_1M)
+		*fl_pte = 0;
+
+	sl_table = (unsigned long *) __va(((*fl_pte) & FL_BASE_MASK));
+	sl_offset = SL_OFFSET(va);
+	sl_pte = sl_table + sl_offset;
+
+	if (len == SZ_64K) {
+		for (i = 0; i < 16; i++)
+			*(sl_pte+i) = 0;
+	}
+
+	if (len == SZ_4K)
+		*sl_pte = 0;
+
+	if (len == SZ_4K || len == SZ_64K) {
+		int used = 0;
+
+		for (i = 0; i < NUM_SL_PTE; i++)
+			if (sl_table[i])
+				used = 1;
+		if (!used) {
+			free_page((unsigned long)sl_table);
+			*fl_pte = 0;
+		}
+	}
+
+	__flush_iotlb(domain);
+fail:
+	spin_unlock_irqrestore(&msm_iommu_lock, flags);
+	return ret;
+}
+
+static phys_addr_t msm_iommu_iova_to_phys(struct iommu_domain *domain,
+					  unsigned long va)
+{
+	struct msm_priv *priv;
+	struct msm_iommu_drvdata *iommu_drvdata;
+	struct msm_iommu_ctx_drvdata *ctx_drvdata;
+	unsigned int par;
+	unsigned long flags;
+	void __iomem *base;
+	phys_addr_t ret = 0;
+	int ctx;
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+
+	priv = domain->priv;
+	if (list_empty(&priv->list_attached))
+		goto fail;
+
+	ctx_drvdata = list_entry(priv->list_attached.next,
+				 struct msm_iommu_ctx_drvdata, attached_elm);
+	iommu_drvdata = dev_get_drvdata(ctx_drvdata->pdev->dev.parent);
+
+	base = iommu_drvdata->base;
+	ctx = ctx_drvdata->num;
+
+	/* Invalidate context TLB */
+	SET_CTX_TLBIALL(base, ctx, 0);
+	SET_V2PPR_VA(base, ctx, va >> V2Pxx_VA_SHIFT);
+
+	if (GET_FAULT(base, ctx))
+		goto fail;
+
+	par = GET_PAR(base, ctx);
+
+	/* We are dealing with a supersection */
+	if (GET_NOFAULT_SS(base, ctx))
+		ret = (par & 0xFF000000) | (va & 0x00FFFFFF);
+	else	/* Upper 20 bits from PAR, lower 12 from VA */
+		ret = (par & 0xFFFFF000) | (va & 0x00000FFF);
+
+fail:
+	spin_unlock_irqrestore(&msm_iommu_lock, flags);
+	return ret;
+}
+
+static int msm_iommu_domain_has_cap(struct iommu_domain *domain,
+				    unsigned long cap)
+{
+	return 0;
+}
+
+static void print_ctx_regs(void __iomem *base, int ctx)
+{
+	unsigned int fsr = GET_FSR(base, ctx);
+	pr_err("FAR    = %08x    PAR    = %08x\n",
+	       GET_FAR(base, ctx), GET_PAR(base, ctx));
+	pr_err("FSR    = %08x [%s%s%s%s%s%s%s%s%s%s]\n", fsr,
+			(fsr & 0x02) ? "TF " : "",
+			(fsr & 0x04) ? "AFF " : "",
+			(fsr & 0x08) ? "APF " : "",
+			(fsr & 0x10) ? "TLBMF " : "",
+			(fsr & 0x20) ? "HTWDEEF " : "",
+			(fsr & 0x40) ? "HTWSEEF " : "",
+			(fsr & 0x80) ? "MHF " : "",
+			(fsr & 0x10000) ? "SL " : "",
+			(fsr & 0x40000000) ? "SS " : "",
+			(fsr & 0x80000000) ? "MULTI " : "");
+
+	pr_err("FSYNR0 = %08x    FSYNR1 = %08x\n",
+	       GET_FSYNR0(base, ctx), GET_FSYNR1(base, ctx));
+	pr_err("TTBR0  = %08x    TTBR1  = %08x\n",
+	       GET_TTBR0(base, ctx), GET_TTBR1(base, ctx));
+	pr_err("SCTLR  = %08x    ACTLR  = %08x\n",
+	       GET_SCTLR(base, ctx), GET_ACTLR(base, ctx));
+	pr_err("PRRR   = %08x    NMRR   = %08x\n",
+	       GET_PRRR(base, ctx), GET_NMRR(base, ctx));
+}
+
+irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id)
+{
+	struct msm_iommu_drvdata *drvdata = dev_id;
+	void __iomem *base;
+	unsigned int fsr = 0;
+	int ncb = 0, i = 0;
+
+	spin_lock(&msm_iommu_lock);
+
+	if (!drvdata) {
+		pr_err("Invalid device ID in context interrupt handler\n");
+		goto fail;
+	}
+
+	base = drvdata->base;
+
+	pr_err("===== WOAH! =====\n");
+	pr_err("Unexpected IOMMU page fault!\n");
+	pr_err("base = %08x\n", (unsigned int) base);
+
+	ncb = GET_NCB(base)+1;
+	for (i = 0; i < ncb; i++) {
+		fsr = GET_FSR(base, i);
+		if (fsr) {
+			pr_err("Fault occurred in context %d.\n", i);
+			pr_err("Interesting registers:\n");
+			print_ctx_regs(base, i);
+			SET_FSR(base, i, 0x4000000F);
+		}
+	}
+fail:
+	spin_unlock(&msm_iommu_lock);
+	return 0;
+}
+
+static struct iommu_ops msm_iommu_ops = {
+	.domain_init = msm_iommu_domain_init,
+	.domain_destroy = msm_iommu_domain_destroy,
+	.attach_dev = msm_iommu_attach_dev,
+	.detach_dev = msm_iommu_detach_dev,
+	.map = msm_iommu_map,
+	.unmap = msm_iommu_unmap,
+	.iova_to_phys = msm_iommu_iova_to_phys,
+	.domain_has_cap = msm_iommu_domain_has_cap
+};
+
+static int msm_iommu_init(void)
+{
+	register_iommu(&msm_iommu_ops);
+	return 0;
+}
+
+subsys_initcall(msm_iommu_init);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Stepan Moskovchenko <stepanm@codeaurora.org>");