Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 827 insertions, 0 deletions

diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
new file mode 100644
index 000000000..16179a9a7
--- /dev/null
+++ b/drivers/iommu/msm_iommu.c
@@ -0,0 +1,827 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * Author: Stepan Moskovchenko <stepanm@codeaurora.org>
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/io-pgtable.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/iommu.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+
+#include <asm/cacheflush.h>
+#include <linux/sizes.h>
+
+#include "msm_iommu_hw-8xxx.h"
+#include "msm_iommu.h"
+
+#define MRC(reg, processor, op1, crn, crm, op2)				\
+__asm__ __volatile__ (							\
+"   mrc   "   #processor "," #op1 ", %0,"  #crn "," #crm "," #op2 "\n"  \
+: "=r" (reg))
+
+/* bitmap of the page sizes currently supported */
+#define MSM_IOMMU_PGSIZES	(SZ_4K | SZ_64K | SZ_1M | SZ_16M)
+
+static DEFINE_SPINLOCK(msm_iommu_lock);
+static LIST_HEAD(qcom_iommu_devices);
+static struct iommu_ops msm_iommu_ops;
+
+struct msm_priv {
+	struct list_head list_attached;
+	struct iommu_domain domain;
+	struct io_pgtable_cfg	cfg;
+	struct io_pgtable_ops	*iop;
+	struct device		*dev;
+	spinlock_t		pgtlock; /* pagetable lock */
+};
+
+static struct msm_priv *to_msm_priv(struct iommu_domain *dom)
+{
+	return container_of(dom, struct msm_priv, domain);
+}
+
+static int __enable_clocks(struct msm_iommu_dev *iommu)
+{
+	int ret;
+
+	ret = clk_enable(iommu->pclk);
+	if (ret)
+		goto fail;
+
+	if (iommu->clk) {
+		ret = clk_enable(iommu->clk);
+		if (ret)
+			clk_disable(iommu->pclk);
+	}
+fail:
+	return ret;
+}
+
+static void __disable_clocks(struct msm_iommu_dev *iommu)
+{
+	if (iommu->clk)
+		clk_disable(iommu->clk);
+	clk_disable(iommu->pclk);
+}
+
+static void msm_iommu_reset(void __iomem *base, int ncb)
+{
+	int ctx;
+
+	SET_RPUE(base, 0);
+	SET_RPUEIE(base, 0);
+	SET_ESRRESTORE(base, 0);
+	SET_TBE(base, 0);
+	SET_CR(base, 0);
+	SET_SPDMBE(base, 0);
+	SET_TESTBUSCR(base, 0);
+	SET_TLBRSW(base, 0);
+	SET_GLOBAL_TLBIALL(base, 0);
+	SET_RPU_ACR(base, 0);
+	SET_TLBLKCRWE(base, 1);
+
+	for (ctx = 0; ctx < ncb; 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_CONTEXTIDR(base, ctx, 0);
+	}
+}
+
+static void __flush_iotlb(void *cookie)
+{
+	struct msm_priv *priv = cookie;
+	struct msm_iommu_dev *iommu = NULL;
+	struct msm_iommu_ctx_dev *master;
+	int ret = 0;
+
+	list_for_each_entry(iommu, &priv->list_attached, dom_node) {
+		ret = __enable_clocks(iommu);
+		if (ret)
+			goto fail;
+
+		list_for_each_entry(master, &iommu->ctx_list, list)
+			SET_CTX_TLBIALL(iommu->base, master->num, 0);
+
+		__disable_clocks(iommu);
+	}
+fail:
+	return;
+}
+
+static void __flush_iotlb_range(unsigned long iova, size_t size,
+				size_t granule, bool leaf, void *cookie)
+{
+	struct msm_priv *priv = cookie;
+	struct msm_iommu_dev *iommu = NULL;
+	struct msm_iommu_ctx_dev *master;
+	int ret = 0;
+	int temp_size;
+
+	list_for_each_entry(iommu, &priv->list_attached, dom_node) {
+		ret = __enable_clocks(iommu);
+		if (ret)
+			goto fail;
+
+		list_for_each_entry(master, &iommu->ctx_list, list) {
+			temp_size = size;
+			do {
+				iova &= TLBIVA_VA;
+				iova |= GET_CONTEXTIDR_ASID(iommu->base,
+							    master->num);
+				SET_TLBIVA(iommu->base, master->num, iova);
+				iova += granule;
+			} while (temp_size -= granule);
+		}
+
+		__disable_clocks(iommu);
+	}
+
+fail:
+	return;
+}
+
+static void __flush_iotlb_walk(unsigned long iova, size_t size,
+			       size_t granule, void *cookie)
+{
+	__flush_iotlb_range(iova, size, granule, false, cookie);
+}
+
+static void __flush_iotlb_page(struct iommu_iotlb_gather *gather,
+			       unsigned long iova, size_t granule, void *cookie)
+{
+	__flush_iotlb_range(iova, granule, granule, true, cookie);
+}
+
+static const struct iommu_flush_ops msm_iommu_flush_ops = {
+	.tlb_flush_all = __flush_iotlb,
+	.tlb_flush_walk = __flush_iotlb_walk,
+	.tlb_add_page = __flush_iotlb_page,
+};
+
+static int msm_iommu_alloc_ctx(unsigned long *map, int start, int end)
+{
+	int idx;
+
+	do {
+		idx = find_next_zero_bit(map, end, start);
+		if (idx == end)
+			return -ENOSPC;
+	} while (test_and_set_bit(idx, map));
+
+	return idx;
+}
+
+static void msm_iommu_free_ctx(unsigned long *map, int idx)
+{
+	clear_bit(idx, map);
+}
+
+static void config_mids(struct msm_iommu_dev *iommu,
+			struct msm_iommu_ctx_dev *master)
+{
+	int mid, ctx, i;
+
+	for (i = 0; i < master->num_mids; i++) {
+		mid = master->mids[i];
+		ctx = master->num;
+
+		SET_M2VCBR_N(iommu->base, mid, 0);
+		SET_CBACR_N(iommu->base, ctx, 0);
+
+		/* Set VMID = 0 */
+		SET_VMID(iommu->base, mid, 0);
+
+		/* Set the context number for that MID to this context */
+		SET_CBNDX(iommu->base, mid, ctx);
+
+		/* Set MID associated with this context bank to 0*/
+		SET_CBVMID(iommu->base, ctx, 0);
+
+		/* Set the ASID for TLB tagging for this context */
+		SET_CONTEXTIDR_ASID(iommu->base, ctx, ctx);
+
+		/* Set security bit override to be Non-secure */
+		SET_NSCFG(iommu->base, mid, 3);
+	}
+}
+
+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);
+}
+
+static void __program_context(void __iomem *base, int ctx,
+			      struct msm_priv *priv)
+{
+	__reset_context(base, ctx);
+
+	/* Turn on TEX Remap */
+	SET_TRE(base, ctx, 1);
+	SET_AFE(base, ctx, 1);
+
+	/* 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, priv->cfg.arm_v7s_cfg.tcr);
+	SET_TTBR0(base, ctx, priv->cfg.arm_v7s_cfg.ttbr);
+	SET_TTBR1(base, ctx, 0);
+
+	/* Set prrr and nmrr */
+	SET_PRRR(base, ctx, priv->cfg.arm_v7s_cfg.prrr);
+	SET_NMRR(base, ctx, priv->cfg.arm_v7s_cfg.nmrr);
+
+	/* 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 BFB prefetch */
+	SET_BFBDFE(base, ctx, 1);
+
+	/* Enable the MMU */
+	SET_M(base, ctx, 1);
+}
+
+static struct iommu_domain *msm_iommu_domain_alloc(unsigned type)
+{
+	struct msm_priv *priv;
+
+	if (type != IOMMU_DOMAIN_UNMANAGED)
+		return NULL;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		goto fail_nomem;
+
+	INIT_LIST_HEAD(&priv->list_attached);
+
+	priv->domain.geometry.aperture_start = 0;
+	priv->domain.geometry.aperture_end   = (1ULL << 32) - 1;
+	priv->domain.geometry.force_aperture = true;
+
+	return &priv->domain;
+
+fail_nomem:
+	kfree(priv);
+	return NULL;
+}
+
+static void msm_iommu_domain_free(struct iommu_domain *domain)
+{
+	struct msm_priv *priv;
+	unsigned long flags;
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+	priv = to_msm_priv(domain);
+	kfree(priv);
+	spin_unlock_irqrestore(&msm_iommu_lock, flags);
+}
+
+static int msm_iommu_domain_config(struct msm_priv *priv)
+{
+	spin_lock_init(&priv->pgtlock);
+
+	priv->cfg = (struct io_pgtable_cfg) {
+		.pgsize_bitmap = msm_iommu_ops.pgsize_bitmap,
+		.ias = 32,
+		.oas = 32,
+		.tlb = &msm_iommu_flush_ops,
+		.iommu_dev = priv->dev,
+	};
+
+	priv->iop = alloc_io_pgtable_ops(ARM_V7S, &priv->cfg, priv);
+	if (!priv->iop) {
+		dev_err(priv->dev, "Failed to allocate pgtable\n");
+		return -EINVAL;
+	}
+
+	msm_iommu_ops.pgsize_bitmap = priv->cfg.pgsize_bitmap;
+
+	return 0;
+}
+
+/* Must be called under msm_iommu_lock */
+static struct msm_iommu_dev *find_iommu_for_dev(struct device *dev)
+{
+	struct msm_iommu_dev *iommu, *ret = NULL;
+	struct msm_iommu_ctx_dev *master;
+
+	list_for_each_entry(iommu, &qcom_iommu_devices, dev_node) {
+		master = list_first_entry(&iommu->ctx_list,
+					  struct msm_iommu_ctx_dev,
+					  list);
+		if (master->of_node == dev->of_node) {
+			ret = iommu;
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static struct iommu_device *msm_iommu_probe_device(struct device *dev)
+{
+	struct msm_iommu_dev *iommu;
+	unsigned long flags;
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+	iommu = find_iommu_for_dev(dev);
+	spin_unlock_irqrestore(&msm_iommu_lock, flags);
+
+	if (!iommu)
+		return ERR_PTR(-ENODEV);
+
+	return &iommu->iommu;
+}
+
+static int msm_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
+{
+	int ret = 0;
+	unsigned long flags;
+	struct msm_iommu_dev *iommu;
+	struct msm_priv *priv = to_msm_priv(domain);
+	struct msm_iommu_ctx_dev *master;
+
+	priv->dev = dev;
+	msm_iommu_domain_config(priv);
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+	list_for_each_entry(iommu, &qcom_iommu_devices, dev_node) {
+		master = list_first_entry(&iommu->ctx_list,
+					  struct msm_iommu_ctx_dev,
+					  list);
+		if (master->of_node == dev->of_node) {
+			ret = __enable_clocks(iommu);
+			if (ret)
+				goto fail;
+
+			list_for_each_entry(master, &iommu->ctx_list, list) {
+				if (master->num) {
+					dev_err(dev, "domain already attached");
+					ret = -EEXIST;
+					goto fail;
+				}
+				master->num =
+					msm_iommu_alloc_ctx(iommu->context_map,
+							    0, iommu->ncb);
+				if (IS_ERR_VALUE(master->num)) {
+					ret = -ENODEV;
+					goto fail;
+				}
+				config_mids(iommu, master);
+				__program_context(iommu->base, master->num,
+						  priv);
+			}
+			__disable_clocks(iommu);
+			list_add(&iommu->dom_node, &priv->list_attached);
+		}
+	}
+
+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 = to_msm_priv(domain);
+	unsigned long flags;
+	struct msm_iommu_dev *iommu;
+	struct msm_iommu_ctx_dev *master;
+	int ret;
+
+	free_io_pgtable_ops(priv->iop);
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+	list_for_each_entry(iommu, &priv->list_attached, dom_node) {
+		ret = __enable_clocks(iommu);
+		if (ret)
+			goto fail;
+
+		list_for_each_entry(master, &iommu->ctx_list, list) {
+			msm_iommu_free_ctx(iommu->context_map, master->num);
+			__reset_context(iommu->base, master->num);
+		}
+		__disable_clocks(iommu);
+	}
+fail:
+	spin_unlock_irqrestore(&msm_iommu_lock, flags);
+}
+
+static int msm_iommu_map(struct iommu_domain *domain, unsigned long iova,
+			 phys_addr_t pa, size_t len, int prot, gfp_t gfp)
+{
+	struct msm_priv *priv = to_msm_priv(domain);
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&priv->pgtlock, flags);
+	ret = priv->iop->map(priv->iop, iova, pa, len, prot, GFP_ATOMIC);
+	spin_unlock_irqrestore(&priv->pgtlock, flags);
+
+	return ret;
+}
+
+static void msm_iommu_sync_map(struct iommu_domain *domain, unsigned long iova,
+			       size_t size)
+{
+	struct msm_priv *priv = to_msm_priv(domain);
+
+	__flush_iotlb_range(iova, size, SZ_4K, false, priv);
+}
+
+static size_t msm_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
+			      size_t len, struct iommu_iotlb_gather *gather)
+{
+	struct msm_priv *priv = to_msm_priv(domain);
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->pgtlock, flags);
+	len = priv->iop->unmap(priv->iop, iova, len, gather);
+	spin_unlock_irqrestore(&priv->pgtlock, flags);
+
+	return len;
+}
+
+static phys_addr_t msm_iommu_iova_to_phys(struct iommu_domain *domain,
+					  dma_addr_t va)
+{
+	struct msm_priv *priv;
+	struct msm_iommu_dev *iommu;
+	struct msm_iommu_ctx_dev *master;
+	unsigned int par;
+	unsigned long flags;
+	phys_addr_t ret = 0;
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+
+	priv = to_msm_priv(domain);
+	iommu = list_first_entry(&priv->list_attached,
+				 struct msm_iommu_dev, dom_node);
+
+	if (list_empty(&iommu->ctx_list))
+		goto fail;
+
+	master = list_first_entry(&iommu->ctx_list,
+				  struct msm_iommu_ctx_dev, list);
+	if (!master)
+		goto fail;
+
+	ret = __enable_clocks(iommu);
+	if (ret)
+		goto fail;
+
+	/* Invalidate context TLB */
+	SET_CTX_TLBIALL(iommu->base, master->num, 0);
+	SET_V2PPR(iommu->base, master->num, va & V2Pxx_VA);
+
+	par = GET_PAR(iommu->base, master->num);
+
+	/* We are dealing with a supersection */
+	if (GET_NOFAULT_SS(iommu->base, master->num))
+		ret = (par & 0xFF000000) | (va & 0x00FFFFFF);
+	else	/* Upper 20 bits from PAR, lower 12 from VA */
+		ret = (par & 0xFFFFF000) | (va & 0x00000FFF);
+
+	if (GET_FAULT(iommu->base, master->num))
+		ret = 0;
+
+	__disable_clocks(iommu);
+fail:
+	spin_unlock_irqrestore(&msm_iommu_lock, flags);
+	return ret;
+}
+
+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));
+}
+
+static int insert_iommu_master(struct device *dev,
+				struct msm_iommu_dev **iommu,
+				struct of_phandle_args *spec)
+{
+	struct msm_iommu_ctx_dev *master = dev_iommu_priv_get(dev);
+	int sid;
+
+	if (list_empty(&(*iommu)->ctx_list)) {
+		master = kzalloc(sizeof(*master), GFP_ATOMIC);
+		if (!master) {
+			dev_err(dev, "Failed to allocate iommu_master\n");
+			return -ENOMEM;
+		}
+		master->of_node = dev->of_node;
+		list_add(&master->list, &(*iommu)->ctx_list);
+		dev_iommu_priv_set(dev, master);
+	}
+
+	for (sid = 0; sid < master->num_mids; sid++)
+		if (master->mids[sid] == spec->args[0]) {
+			dev_warn(dev, "Stream ID 0x%x repeated; ignoring\n",
+				 sid);
+			return 0;
+		}
+
+	master->mids[master->num_mids++] = spec->args[0];
+	return 0;
+}
+
+static int qcom_iommu_of_xlate(struct device *dev,
+			       struct of_phandle_args *spec)
+{
+	struct msm_iommu_dev *iommu = NULL, *iter;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&msm_iommu_lock, flags);
+	list_for_each_entry(iter, &qcom_iommu_devices, dev_node) {
+		if (iter->dev->of_node == spec->np) {
+			iommu = iter;
+			break;
+		}
+	}
+
+	if (!iommu) {
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	ret = insert_iommu_master(dev, &iommu, spec);
+fail:
+	spin_unlock_irqrestore(&msm_iommu_lock, flags);
+
+	return ret;
+}
+
+irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id)
+{
+	struct msm_iommu_dev *iommu = dev_id;
+	unsigned int fsr;
+	int i, ret;
+
+	spin_lock(&msm_iommu_lock);
+
+	if (!iommu) {
+		pr_err("Invalid device ID in context interrupt handler\n");
+		goto fail;
+	}
+
+	pr_err("Unexpected IOMMU page fault!\n");
+	pr_err("base = %08x\n", (unsigned int)iommu->base);
+
+	ret = __enable_clocks(iommu);
+	if (ret)
+		goto fail;
+
+	for (i = 0; i < iommu->ncb; i++) {
+		fsr = GET_FSR(iommu->base, i);
+		if (fsr) {
+			pr_err("Fault occurred in context %d.\n", i);
+			pr_err("Interesting registers:\n");
+			print_ctx_regs(iommu->base, i);
+			SET_FSR(iommu->base, i, 0x4000000F);
+		}
+	}
+	__disable_clocks(iommu);
+fail:
+	spin_unlock(&msm_iommu_lock);
+	return 0;
+}
+
+static struct iommu_ops msm_iommu_ops = {
+	.domain_alloc = msm_iommu_domain_alloc,
+	.probe_device = msm_iommu_probe_device,
+	.device_group = generic_device_group,
+	.pgsize_bitmap = MSM_IOMMU_PGSIZES,
+	.of_xlate = qcom_iommu_of_xlate,
+	.default_domain_ops = &(const struct iommu_domain_ops) {
+		.attach_dev	= msm_iommu_attach_dev,
+		.detach_dev	= msm_iommu_detach_dev,
+		.map		= msm_iommu_map,
+		.unmap		= msm_iommu_unmap,
+		/*
+		 * Nothing is needed here, the barrier to guarantee
+		 * completion of the tlb sync operation is implicitly
+		 * taken care when the iommu client does a writel before
+		 * kick starting the other master.
+		 */
+		.iotlb_sync	= NULL,
+		.iotlb_sync_map	= msm_iommu_sync_map,
+		.iova_to_phys	= msm_iommu_iova_to_phys,
+		.free		= msm_iommu_domain_free,
+	}
+};
+
+static int msm_iommu_probe(struct platform_device *pdev)
+{
+	struct resource *r;
+	resource_size_t ioaddr;
+	struct msm_iommu_dev *iommu;
+	int ret, par, val;
+
+	iommu = devm_kzalloc(&pdev->dev, sizeof(*iommu), GFP_KERNEL);
+	if (!iommu)
+		return -ENODEV;
+
+	iommu->dev = &pdev->dev;
+	INIT_LIST_HEAD(&iommu->ctx_list);
+
+	iommu->pclk = devm_clk_get(iommu->dev, "smmu_pclk");
+	if (IS_ERR(iommu->pclk))
+		return dev_err_probe(iommu->dev, PTR_ERR(iommu->pclk),
+				     "could not get smmu_pclk\n");
+
+	ret = clk_prepare(iommu->pclk);
+	if (ret)
+		return dev_err_probe(iommu->dev, ret,
+				     "could not prepare smmu_pclk\n");
+
+	iommu->clk = devm_clk_get(iommu->dev, "iommu_clk");
+	if (IS_ERR(iommu->clk)) {
+		clk_unprepare(iommu->pclk);
+		return dev_err_probe(iommu->dev, PTR_ERR(iommu->clk),
+				     "could not get iommu_clk\n");
+	}
+
+	ret = clk_prepare(iommu->clk);
+	if (ret) {
+		clk_unprepare(iommu->pclk);
+		return dev_err_probe(iommu->dev, ret, "could not prepare iommu_clk\n");
+	}
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	iommu->base = devm_ioremap_resource(iommu->dev, r);
+	if (IS_ERR(iommu->base)) {
+		ret = dev_err_probe(iommu->dev, PTR_ERR(iommu->base), "could not get iommu base\n");
+		goto fail;
+	}
+	ioaddr = r->start;
+
+	iommu->irq = platform_get_irq(pdev, 0);
+	if (iommu->irq < 0) {
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	ret = of_property_read_u32(iommu->dev->of_node, "qcom,ncb", &val);
+	if (ret) {
+		dev_err(iommu->dev, "could not get ncb\n");
+		goto fail;
+	}
+	iommu->ncb = val;
+
+	msm_iommu_reset(iommu->base, iommu->ncb);
+	SET_M(iommu->base, 0, 1);
+	SET_PAR(iommu->base, 0, 0);
+	SET_V2PCFG(iommu->base, 0, 1);
+	SET_V2PPR(iommu->base, 0, 0);
+	par = GET_PAR(iommu->base, 0);
+	SET_V2PCFG(iommu->base, 0, 0);
+	SET_M(iommu->base, 0, 0);
+
+	if (!par) {
+		pr_err("Invalid PAR value detected\n");
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	ret = devm_request_threaded_irq(iommu->dev, iommu->irq, NULL,
+					msm_iommu_fault_handler,
+					IRQF_ONESHOT | IRQF_SHARED,
+					"msm_iommu_secure_irpt_handler",
+					iommu);
+	if (ret) {
+		pr_err("Request IRQ %d failed with ret=%d\n", iommu->irq, ret);
+		goto fail;
+	}
+
+	list_add(&iommu->dev_node, &qcom_iommu_devices);
+
+	ret = iommu_device_sysfs_add(&iommu->iommu, iommu->dev, NULL,
+				     "msm-smmu.%pa", &ioaddr);
+	if (ret) {
+		pr_err("Could not add msm-smmu at %pa to sysfs\n", &ioaddr);
+		goto fail;
+	}
+
+	ret = iommu_device_register(&iommu->iommu, &msm_iommu_ops, &pdev->dev);
+	if (ret) {
+		pr_err("Could not register msm-smmu at %pa\n", &ioaddr);
+		goto fail;
+	}
+
+	pr_info("device mapped at %p, irq %d with %d ctx banks\n",
+		iommu->base, iommu->irq, iommu->ncb);
+
+	return ret;
+fail:
+	clk_unprepare(iommu->clk);
+	clk_unprepare(iommu->pclk);
+	return ret;
+}
+
+static const struct of_device_id msm_iommu_dt_match[] = {
+	{ .compatible = "qcom,apq8064-iommu" },
+	{}
+};
+
+static int msm_iommu_remove(struct platform_device *pdev)
+{
+	struct msm_iommu_dev *iommu = platform_get_drvdata(pdev);
+
+	clk_unprepare(iommu->clk);
+	clk_unprepare(iommu->pclk);
+	return 0;
+}
+
+static struct platform_driver msm_iommu_driver = {
+	.driver = {
+		.name	= "msm_iommu",
+		.of_match_table = msm_iommu_dt_match,
+	},
+	.probe		= msm_iommu_probe,
+	.remove		= msm_iommu_remove,
+};
+builtin_platform_driver(msm_iommu_driver);