drivers/iommu/msm_iommu_sec.c - kernel/msm - Gitiles

 /* Copyright (c) 2012 Linux Foundation. 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.
  */

 #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/mutex.h>
 #include <linux/slab.h>
 #include <linux/iommu.h>
 #include <linux/clk.h>
 #include <linux/scatterlist.h>
 #include <linux/of.h>
 #include <linux/of_device.h>

 #include <asm/sizes.h>

 #include <mach/iommu_hw-v2.h>
 #include <mach/iommu.h>
 #include <mach/scm.h>

 /* bitmap of the page sizes currently supported */
 #define MSM_IOMMU_PGSIZES	(SZ_4K | SZ_64K | SZ_1M | SZ_16M)

 #define IOMMU_SECURE_CFG	2
 #define IOMMU_SECURE_PTBL_SIZE  3
 #define IOMMU_SECURE_PTBL_INIT  4
 #define IOMMU_SECURE_MAP	6
 #define IOMMU_SECURE_UNMAP      7

 static DEFINE_MUTEX(msm_iommu_lock);

 struct msm_priv {
 	struct list_head list_attached;
 };

 struct msm_scm_paddr_list {
 	unsigned int list;
 	unsigned int list_size;
 	unsigned int size;
 };

 struct msm_scm_mapping_info {
 	unsigned int id;
 	unsigned int ctx_id;
 	unsigned int va;
 	unsigned int size;
 };

 struct msm_scm_map_req {
 	struct msm_scm_paddr_list plist;
 	struct msm_scm_mapping_info info;
 };

 static int msm_iommu_sec_ptbl_init(void)
 {
 	struct device_node *np;
 	struct msm_scm_ptbl_init {
 		unsigned int paddr;
 		unsigned int size;
 		unsigned int spare;
 	} pinit;
 	unsigned int *buf;
 	int psize[2] = {0, 0};
 	unsigned int spare;
 	int ret, ptbl_ret = 0;

 	for_each_compatible_node(np, NULL, "qcom,msm-smmu-v2")
 		if (of_find_property(np, "qcom,iommu-secure-id", NULL))
 			break;

 	if (!np)
 		return 0;

 	of_node_put(np);
 	ret = scm_call(SCM_SVC_CP, IOMMU_SECURE_PTBL_SIZE, &spare,
 			sizeof(spare), psize, sizeof(psize));
 	if (ret) {
 		pr_err("scm call IOMMU_SECURE_PTBL_SIZE failed\n");
 		goto fail;
 	}

 	if (psize[1]) {
 		pr_err("scm call IOMMU_SECURE_PTBL_SIZE failed\n");
 		goto fail;
 	}

 	buf = kmalloc(psize[0], GFP_KERNEL);
 	if (!buf) {
 		pr_err("%s: Failed to allocate %d bytes for PTBL\n",
 			__func__, psize[0]);
 		ret = -ENOMEM;
 		goto fail;
 	}

 	pinit.paddr = virt_to_phys(buf);
 	pinit.size = psize[0];

 	ret = scm_call(SCM_SVC_CP, IOMMU_SECURE_PTBL_INIT, &pinit,
 			sizeof(pinit), &ptbl_ret, sizeof(ptbl_ret));
 	if (ret) {
 		pr_err("scm call IOMMU_SECURE_PTBL_INIT failed\n");
 		goto fail_mem;
 	}
 	if (ptbl_ret) {
 		pr_err("scm call IOMMU_SECURE_PTBL_INIT extended ret fail\n");
 		goto fail_mem;
 	}

 	return 0;

 fail_mem:
 	kfree(buf);
 fail:
 	return ret;
 }

 int msm_iommu_sec_program_iommu(int sec_id)
 {
 	struct msm_scm_sec_cfg {
 		unsigned int id;
 		unsigned int spare;
 	} cfg;
 	int ret, scm_ret = 0;

 	cfg.id = sec_id;

 	ret = scm_call(SCM_SVC_CP, IOMMU_SECURE_CFG, &cfg, sizeof(cfg),
 			&scm_ret, sizeof(scm_ret));
 	if (ret || scm_ret) {
 		pr_err("scm call IOMMU_SECURE_CFG failed\n");
 		return ret ? ret : -EINVAL;
 	}

 	return ret;
 }

 static int msm_iommu_sec_ptbl_map(struct msm_iommu_drvdata *iommu_drvdata,
 			struct msm_iommu_ctx_drvdata *ctx_drvdata,
 			unsigned long va, phys_addr_t pa, size_t len)
 {
 	struct msm_scm_map_req map;
 	int ret = 0;

 	map.plist.list = virt_to_phys(&pa);
 	map.plist.list_size = 1;
 	map.plist.size = len;
 	map.info.id = iommu_drvdata->sec_id;
 	map.info.ctx_id = ctx_drvdata->num;
 	map.info.va = va;
 	map.info.size = len;

 	if (scm_call(SCM_SVC_CP, IOMMU_SECURE_MAP, &map, sizeof(map), &ret,
 								sizeof(ret)))
 		return -EINVAL;
 	if (ret)
 		return -EINVAL;

 	return 0;
 }

 static unsigned int get_phys_addr(struct scatterlist *sg)
 {
 	/*
 	 * Try sg_dma_address first so that we can
 	 * map carveout regions that do not have a
 	 * struct page associated with them.
 	 */
 	unsigned int pa = sg_dma_address(sg);
 	if (pa == 0)
 		pa = sg_phys(sg);
 	return pa;
 }

 static int msm_iommu_sec_ptbl_map_range(struct msm_iommu_drvdata *iommu_drvdata,
 			struct msm_iommu_ctx_drvdata *ctx_drvdata,
 			unsigned long va, struct scatterlist *sg, size_t len)
 {
 	struct scatterlist *sgiter;
 	struct msm_scm_map_req map;
 	unsigned int *pa_list = 0;
 	unsigned int pa, cnt;
 	unsigned int offset = 0, chunk_offset = 0;
 	int ret, scm_ret;

 	map.info.id = iommu_drvdata->sec_id;
 	map.info.ctx_id = ctx_drvdata->num;
 	map.info.va = va;
 	map.info.size = len;

 	if (sg->length == len) {
 		pa = get_phys_addr(sg);
 		map.plist.list = virt_to_phys(&pa);
 		map.plist.list_size = 1;
 		map.plist.size = len;
 	} else {
 		sgiter = sg;
 		cnt = sg->length / SZ_1M;
 		while ((sgiter = sg_next(sgiter)))
 			cnt += sgiter->length / SZ_1M;

 		pa_list = kmalloc(cnt * sizeof(*pa_list), GFP_KERNEL);
 		if (!pa_list)
 			return -ENOMEM;

 		sgiter = sg;
 		cnt = 0;
 		pa = get_phys_addr(sgiter);
 		while (offset < len) {
 			pa += chunk_offset;
 			pa_list[cnt] = pa;
 			chunk_offset += SZ_1M;
 			offset += SZ_1M;
 			cnt++;

 			if (chunk_offset >= sgiter->length && offset < len) {
 				chunk_offset = 0;
 				sgiter = sg_next(sgiter);
 				pa = get_phys_addr(sgiter);
 			}
 		}

 		map.plist.list = virt_to_phys(pa_list);
 		map.plist.list_size = cnt;
 		map.plist.size = SZ_1M;
 	}

 	ret = scm_call(SCM_SVC_CP, IOMMU_SECURE_MAP, &map, sizeof(map),
 			&scm_ret, sizeof(scm_ret));
 	kfree(pa_list);
 	return ret;
 }

 static int msm_iommu_sec_ptbl_unmap(struct msm_iommu_drvdata *iommu_drvdata,
 			struct msm_iommu_ctx_drvdata *ctx_drvdata,
 			unsigned long va, size_t len)
 {
 	struct msm_scm_mapping_info mi;
 	int ret, scm_ret;

 	mi.id = iommu_drvdata->sec_id;
 	mi.ctx_id = ctx_drvdata->num;
 	mi.va = va;
 	mi.size = len;

 	ret = scm_call(SCM_SVC_CP, IOMMU_SECURE_UNMAP, &mi, sizeof(mi),
 			&scm_ret, sizeof(scm_ret));
 	return ret;
 }

 static int __enable_clocks(struct msm_iommu_drvdata *drvdata)
 {
 	int ret;

 	ret = clk_prepare_enable(drvdata->pclk);
 	if (ret)
 		goto fail;

 	ret = clk_prepare_enable(drvdata->clk);
 	if (ret)
 		clk_disable_unprepare(drvdata->pclk);

 	if (drvdata->aclk) {
 		ret = clk_prepare_enable(drvdata->aclk);
 		if (ret) {
 			clk_disable_unprepare(drvdata->clk);
 			clk_disable_unprepare(drvdata->pclk);
 		}
 	}
 fail:
 	return ret;
 }

 static void __disable_clocks(struct msm_iommu_drvdata *drvdata)
 {
 	if (drvdata->aclk)
 		clk_disable_unprepare(drvdata->aclk);
 	clk_disable_unprepare(drvdata->clk);
 	clk_disable_unprepare(drvdata->pclk);
 }

 static int msm_iommu_domain_init(struct iommu_domain *domain, int flags)
 {
 	struct msm_priv *priv;

 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	INIT_LIST_HEAD(&priv->list_attached);
 	domain->priv = priv;
 	return 0;
 }

 static void msm_iommu_domain_destroy(struct iommu_domain *domain)
 {
 	struct msm_priv *priv;

 	mutex_lock(&msm_iommu_lock);
 	priv = domain->priv;
 	domain->priv = NULL;

 	kfree(priv);
 	mutex_unlock(&msm_iommu_lock);
 }

 static int msm_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
 {
 	struct msm_priv *priv;
 	struct msm_iommu_drvdata *iommu_drvdata;
 	struct msm_iommu_ctx_drvdata *ctx_drvdata;
 	struct msm_iommu_ctx_drvdata *tmp_drvdata;
 	int ret = 0;

 	mutex_lock(&msm_iommu_lock);

 	priv = domain->priv;
 	if (!priv || !dev) {
 		ret = -EINVAL;
 		goto fail;
 	}

 	iommu_drvdata = dev_get_drvdata(dev->parent);
 	ctx_drvdata = dev_get_drvdata(dev);
 	if (!iommu_drvdata || !ctx_drvdata) {
 		ret = -EINVAL;
 		goto fail;
 	}

 	if (!list_empty(&ctx_drvdata->attached_elm)) {
 		ret = -EBUSY;
 		goto fail;
 	}

 	list_for_each_entry(tmp_drvdata, &priv->list_attached, attached_elm)
 		if (tmp_drvdata == ctx_drvdata) {
 			ret = -EBUSY;
 			goto fail;
 		}

 	ret = regulator_enable(iommu_drvdata->gdsc);
 	if (ret)
 		goto fail;

 	ret = __enable_clocks(iommu_drvdata);
 	if (ret) {
 		regulator_disable(iommu_drvdata->gdsc);
 		goto fail;
 	}

 	ret = msm_iommu_sec_program_iommu(iommu_drvdata->sec_id);
 	__disable_clocks(iommu_drvdata);
 	if (ret) {
 		regulator_disable(iommu_drvdata->gdsc);
 		goto fail;
 	}

 	list_add(&(ctx_drvdata->attached_elm), &priv->list_attached);
 	ctx_drvdata->attached_domain = domain;

 fail:
 	mutex_unlock(&msm_iommu_lock);
 	return ret;
 }

 static void msm_iommu_detach_dev(struct iommu_domain *domain,
 				 struct device *dev)
 {
 	struct msm_iommu_drvdata *iommu_drvdata;
 	struct msm_iommu_ctx_drvdata *ctx_drvdata;

 	mutex_lock(&msm_iommu_lock);
 	if (!dev)
 		goto fail;

 	iommu_drvdata = dev_get_drvdata(dev->parent);
 	ctx_drvdata = dev_get_drvdata(dev);
 	if (!iommu_drvdata || !ctx_drvdata || !ctx_drvdata->attached_domain)
 		goto fail;

 	list_del_init(&ctx_drvdata->attached_elm);
 	ctx_drvdata->attached_domain = NULL;

 	regulator_disable(iommu_drvdata->gdsc);

 fail:
 	mutex_unlock(&msm_iommu_lock);
 }

 static int get_drvdata(struct iommu_domain *domain,
 			struct msm_iommu_drvdata **iommu_drvdata,
 			struct msm_iommu_ctx_drvdata **ctx_drvdata)
 {
 	struct msm_priv *priv = domain->priv;
 	struct msm_iommu_ctx_drvdata *ctx;

 	list_for_each_entry(ctx, &priv->list_attached, attached_elm) {
 		if (ctx->attached_domain == domain)
 			break;
 	}

 	if (ctx->attached_domain != domain)
 		return -EINVAL;

 	*ctx_drvdata = ctx;
 	*iommu_drvdata = dev_get_drvdata(ctx->pdev->dev.parent);
 	return 0;
 }

 static int msm_iommu_map(struct iommu_domain *domain, unsigned long va,
 			 phys_addr_t pa, size_t len, int prot)
 {
 	struct msm_iommu_drvdata *iommu_drvdata;
 	struct msm_iommu_ctx_drvdata *ctx_drvdata;
 	int ret = 0;

 	mutex_lock(&msm_iommu_lock);

 	ret = get_drvdata(domain, &iommu_drvdata, &ctx_drvdata);
 	if (ret)
 		goto fail;

 	ret = msm_iommu_sec_ptbl_map(iommu_drvdata, ctx_drvdata,
 					va, pa, len);
 fail:
 	mutex_unlock(&msm_iommu_lock);
 	return ret;
 }

 static size_t msm_iommu_unmap(struct iommu_domain *domain, unsigned long va,
 			    size_t len)
 {
 	struct msm_iommu_drvdata *iommu_drvdata;
 	struct msm_iommu_ctx_drvdata *ctx_drvdata;
 	int ret = -ENODEV;

 	mutex_lock(&msm_iommu_lock);

 	ret = get_drvdata(domain, &iommu_drvdata, &ctx_drvdata);
 	if (ret)
 		goto fail;

 	ret = msm_iommu_sec_ptbl_unmap(iommu_drvdata, ctx_drvdata,
 					va, len);
 fail:
 	mutex_unlock(&msm_iommu_lock);

 	/* the IOMMU API requires us to return how many bytes were unmapped */
 	len = ret ? 0 : len;
 	return len;
 }

 static int msm_iommu_map_range(struct iommu_domain *domain, unsigned int va,
 			       struct scatterlist *sg, unsigned int len,
 			       int prot)
 {
 	int ret;
 	struct msm_iommu_drvdata *iommu_drvdata;
 	struct msm_iommu_ctx_drvdata *ctx_drvdata;

 	mutex_lock(&msm_iommu_lock);

 	ret = get_drvdata(domain, &iommu_drvdata, &ctx_drvdata);
 	if (ret)
 		goto fail;
 	ret = msm_iommu_sec_ptbl_map_range(iommu_drvdata, ctx_drvdata,
 						va, sg, len);
 fail:
 	mutex_unlock(&msm_iommu_lock);
 	return ret;
 }


 static int msm_iommu_unmap_range(struct iommu_domain *domain, unsigned int va,
 				 unsigned int len)
 {
 	struct msm_iommu_drvdata *iommu_drvdata;
 	struct msm_iommu_ctx_drvdata *ctx_drvdata;
 	int ret;

 	mutex_lock(&msm_iommu_lock);

 	ret = get_drvdata(domain, &iommu_drvdata, &ctx_drvdata);
 	if (ret)
 		goto fail;

 	ret = msm_iommu_sec_ptbl_unmap(iommu_drvdata, ctx_drvdata, va, len);

 fail:
 	mutex_unlock(&msm_iommu_lock);
 	return 0;
 }

 static phys_addr_t msm_iommu_iova_to_phys(struct iommu_domain *domain,
 					  unsigned long va)
 {
 	return 0;
 }

 static int msm_iommu_domain_has_cap(struct iommu_domain *domain,
 				    unsigned long cap)
 {
 	return 0;
 }

 static phys_addr_t msm_iommu_get_pt_base_addr(struct iommu_domain *domain)
 {
 	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,
 	.map_range = msm_iommu_map_range,
 	.unmap_range = msm_iommu_unmap_range,
 	.iova_to_phys = msm_iommu_iova_to_phys,
 	.domain_has_cap = msm_iommu_domain_has_cap,
 	.get_pt_base_addr = msm_iommu_get_pt_base_addr,
 	.pgsize_bitmap = MSM_IOMMU_PGSIZES,
 };

 static int __init msm_iommu_sec_init(void)
 {
 	int ret;

 	ret = bus_register(&msm_iommu_sec_bus_type);
 	if (ret)
 		goto fail;

 	bus_set_iommu(&msm_iommu_sec_bus_type, &msm_iommu_ops);
 	ret = msm_iommu_sec_ptbl_init();
 fail:
 	return ret;
 }

 subsys_initcall(msm_iommu_sec_init);

 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("MSM SMMU Secure Driver");
	/* Copyright (c) 2012 Linux Foundation. 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.
	*/

	#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/mutex.h>
	#include <linux/slab.h>
	#include <linux/iommu.h>
	#include <linux/clk.h>
	#include <linux/scatterlist.h>
	#include <linux/of.h>
	#include <linux/of_device.h>

	#include <asm/sizes.h>

	#include <mach/iommu_hw-v2.h>
	#include <mach/iommu.h>
	#include <mach/scm.h>

	/* bitmap of the page sizes currently supported */
	#define MSM_IOMMU_PGSIZES (SZ_4K \| SZ_64K \| SZ_1M \| SZ_16M)

	#define IOMMU_SECURE_CFG 2
	#define IOMMU_SECURE_PTBL_SIZE 3
	#define IOMMU_SECURE_PTBL_INIT 4
	#define IOMMU_SECURE_MAP 6
	#define IOMMU_SECURE_UNMAP 7

	static DEFINE_MUTEX(msm_iommu_lock);

	struct msm_priv {
	struct list_head list_attached;
	};

	struct msm_scm_paddr_list {
	unsigned int list;
	unsigned int list_size;
	unsigned int size;
	};

	struct msm_scm_mapping_info {
	unsigned int id;
	unsigned int ctx_id;
	unsigned int va;
	unsigned int size;
	};

	struct msm_scm_map_req {
	struct msm_scm_paddr_list plist;
	struct msm_scm_mapping_info info;
	};

	static int msm_iommu_sec_ptbl_init(void)
	{
	struct device_node *np;
	struct msm_scm_ptbl_init {
	unsigned int paddr;
	unsigned int size;
	unsigned int spare;
	} pinit;
	unsigned int *buf;
	int psize[2] = {0, 0};
	unsigned int spare;
	int ret, ptbl_ret = 0;

	for_each_compatible_node(np, NULL, "qcom,msm-smmu-v2")
	if (of_find_property(np, "qcom,iommu-secure-id", NULL))
	break;

	if (!np)
	return 0;

	of_node_put(np);
	ret = scm_call(SCM_SVC_CP, IOMMU_SECURE_PTBL_SIZE, &spare,
	sizeof(spare), psize, sizeof(psize));
	if (ret) {
	pr_err("scm call IOMMU_SECURE_PTBL_SIZE failed\n");
	goto fail;
	}

	if (psize[1]) {
	pr_err("scm call IOMMU_SECURE_PTBL_SIZE failed\n");
	goto fail;
	}

	buf = kmalloc(psize[0], GFP_KERNEL);
	if (!buf) {
	pr_err("%s: Failed to allocate %d bytes for PTBL\n",
	__func__, psize[0]);
	ret = -ENOMEM;
	goto fail;
	}

	pinit.paddr = virt_to_phys(buf);
	pinit.size = psize[0];

	ret = scm_call(SCM_SVC_CP, IOMMU_SECURE_PTBL_INIT, &pinit,
	sizeof(pinit), &ptbl_ret, sizeof(ptbl_ret));
	if (ret) {
	pr_err("scm call IOMMU_SECURE_PTBL_INIT failed\n");
	goto fail_mem;
	}
	if (ptbl_ret) {
	pr_err("scm call IOMMU_SECURE_PTBL_INIT extended ret fail\n");
	goto fail_mem;
	}

	return 0;

	fail_mem:
	kfree(buf);
	fail:
	return ret;
	}

	int msm_iommu_sec_program_iommu(int sec_id)
	{
	struct msm_scm_sec_cfg {
	unsigned int id;
	unsigned int spare;
	} cfg;
	int ret, scm_ret = 0;

	cfg.id = sec_id;

	ret = scm_call(SCM_SVC_CP, IOMMU_SECURE_CFG, &cfg, sizeof(cfg),
	&scm_ret, sizeof(scm_ret));
	if (ret \|\| scm_ret) {
	pr_err("scm call IOMMU_SECURE_CFG failed\n");
	return ret ? ret : -EINVAL;
	}

	return ret;
	}

	static int msm_iommu_sec_ptbl_map(struct msm_iommu_drvdata *iommu_drvdata,
	struct msm_iommu_ctx_drvdata *ctx_drvdata,
	unsigned long va, phys_addr_t pa, size_t len)
	{
	struct msm_scm_map_req map;
	int ret = 0;

	map.plist.list = virt_to_phys(&pa);
	map.plist.list_size = 1;
	map.plist.size = len;
	map.info.id = iommu_drvdata->sec_id;
	map.info.ctx_id = ctx_drvdata->num;
	map.info.va = va;
	map.info.size = len;

	if (scm_call(SCM_SVC_CP, IOMMU_SECURE_MAP, &map, sizeof(map), &ret,
	sizeof(ret)))
	return -EINVAL;
	if (ret)
	return -EINVAL;

	return 0;
	}

	static unsigned int get_phys_addr(struct scatterlist *sg)
	{
	/*
	* Try sg_dma_address first so that we can
	* map carveout regions that do not have a
	* struct page associated with them.
	*/
	unsigned int pa = sg_dma_address(sg);
	if (pa == 0)
	pa = sg_phys(sg);
	return pa;
	}

	static int msm_iommu_sec_ptbl_map_range(struct msm_iommu_drvdata *iommu_drvdata,
	struct msm_iommu_ctx_drvdata *ctx_drvdata,
	unsigned long va, struct scatterlist *sg, size_t len)
	{
	struct scatterlist *sgiter;
	struct msm_scm_map_req map;
	unsigned int *pa_list = 0;
	unsigned int pa, cnt;
	unsigned int offset = 0, chunk_offset = 0;
	int ret, scm_ret;

	map.info.id = iommu_drvdata->sec_id;
	map.info.ctx_id = ctx_drvdata->num;
	map.info.va = va;
	map.info.size = len;

	if (sg->length == len) {
	pa = get_phys_addr(sg);
	map.plist.list = virt_to_phys(&pa);
	map.plist.list_size = 1;
	map.plist.size = len;
	} else {
	sgiter = sg;
	cnt = sg->length / SZ_1M;
	while ((sgiter = sg_next(sgiter)))
	cnt += sgiter->length / SZ_1M;

	pa_list = kmalloc(cnt * sizeof(*pa_list), GFP_KERNEL);
	if (!pa_list)
	return -ENOMEM;

	sgiter = sg;
	cnt = 0;
	pa = get_phys_addr(sgiter);
	while (offset < len) {
	pa += chunk_offset;
	pa_list[cnt] = pa;
	chunk_offset += SZ_1M;
	offset += SZ_1M;
	cnt++;

	if (chunk_offset >= sgiter->length && offset < len) {
	chunk_offset = 0;
	sgiter = sg_next(sgiter);
	pa = get_phys_addr(sgiter);
	}
	}

	map.plist.list = virt_to_phys(pa_list);
	map.plist.list_size = cnt;
	map.plist.size = SZ_1M;
	}

	ret = scm_call(SCM_SVC_CP, IOMMU_SECURE_MAP, &map, sizeof(map),
	&scm_ret, sizeof(scm_ret));
	kfree(pa_list);
	return ret;
	}

	static int msm_iommu_sec_ptbl_unmap(struct msm_iommu_drvdata *iommu_drvdata,
	struct msm_iommu_ctx_drvdata *ctx_drvdata,
	unsigned long va, size_t len)
	{
	struct msm_scm_mapping_info mi;
	int ret, scm_ret;

	mi.id = iommu_drvdata->sec_id;
	mi.ctx_id = ctx_drvdata->num;
	mi.va = va;
	mi.size = len;

	ret = scm_call(SCM_SVC_CP, IOMMU_SECURE_UNMAP, &mi, sizeof(mi),
	&scm_ret, sizeof(scm_ret));
	return ret;
	}

	static int __enable_clocks(struct msm_iommu_drvdata *drvdata)
	{
	int ret;

	ret = clk_prepare_enable(drvdata->pclk);
	if (ret)
	goto fail;

	ret = clk_prepare_enable(drvdata->clk);
	if (ret)
	clk_disable_unprepare(drvdata->pclk);

	if (drvdata->aclk) {
	ret = clk_prepare_enable(drvdata->aclk);
	if (ret) {
	clk_disable_unprepare(drvdata->clk);
	clk_disable_unprepare(drvdata->pclk);
	}
	}
	fail:
	return ret;
	}

	static void __disable_clocks(struct msm_iommu_drvdata *drvdata)
	{
	if (drvdata->aclk)
	clk_disable_unprepare(drvdata->aclk);
	clk_disable_unprepare(drvdata->clk);
	clk_disable_unprepare(drvdata->pclk);
	}

	static int msm_iommu_domain_init(struct iommu_domain *domain, int flags)
	{
	struct msm_priv *priv;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	INIT_LIST_HEAD(&priv->list_attached);
	domain->priv = priv;
	return 0;
	}

	static void msm_iommu_domain_destroy(struct iommu_domain *domain)
	{
	struct msm_priv *priv;

	mutex_lock(&msm_iommu_lock);
	priv = domain->priv;
	domain->priv = NULL;

	kfree(priv);
	mutex_unlock(&msm_iommu_lock);
	}

	static int msm_iommu_attach_dev(struct iommu_domain domain, struct device dev)
	{
	struct msm_priv *priv;
	struct msm_iommu_drvdata *iommu_drvdata;
	struct msm_iommu_ctx_drvdata *ctx_drvdata;
	struct msm_iommu_ctx_drvdata *tmp_drvdata;
	int ret = 0;

	mutex_lock(&msm_iommu_lock);

	priv = domain->priv;
	if (!priv \|\| !dev) {
	ret = -EINVAL;
	goto fail;
	}

	iommu_drvdata = dev_get_drvdata(dev->parent);
	ctx_drvdata = dev_get_drvdata(dev);
	if (!iommu_drvdata \|\| !ctx_drvdata) {
	ret = -EINVAL;
	goto fail;
	}

	if (!list_empty(&ctx_drvdata->attached_elm)) {
	ret = -EBUSY;
	goto fail;
	}

	list_for_each_entry(tmp_drvdata, &priv->list_attached, attached_elm)
	if (tmp_drvdata == ctx_drvdata) {
	ret = -EBUSY;
	goto fail;
	}

	ret = regulator_enable(iommu_drvdata->gdsc);
	if (ret)
	goto fail;

	ret = __enable_clocks(iommu_drvdata);
	if (ret) {
	regulator_disable(iommu_drvdata->gdsc);
	goto fail;
	}

	ret = msm_iommu_sec_program_iommu(iommu_drvdata->sec_id);
	__disable_clocks(iommu_drvdata);
	if (ret) {
	regulator_disable(iommu_drvdata->gdsc);
	goto fail;
	}

	list_add(&(ctx_drvdata->attached_elm), &priv->list_attached);
	ctx_drvdata->attached_domain = domain;

	fail:
	mutex_unlock(&msm_iommu_lock);
	return ret;
	}

	static void msm_iommu_detach_dev(struct iommu_domain *domain,
	struct device *dev)
	{
	struct msm_iommu_drvdata *iommu_drvdata;
	struct msm_iommu_ctx_drvdata *ctx_drvdata;

	mutex_lock(&msm_iommu_lock);
	if (!dev)
	goto fail;

	iommu_drvdata = dev_get_drvdata(dev->parent);
	ctx_drvdata = dev_get_drvdata(dev);
	if (!iommu_drvdata \|\| !ctx_drvdata \|\| !ctx_drvdata->attached_domain)
	goto fail;

	list_del_init(&ctx_drvdata->attached_elm);
	ctx_drvdata->attached_domain = NULL;

	regulator_disable(iommu_drvdata->gdsc);

	fail:
	mutex_unlock(&msm_iommu_lock);
	}

	static int get_drvdata(struct iommu_domain *domain,
	struct msm_iommu_drvdata **iommu_drvdata,
	struct msm_iommu_ctx_drvdata **ctx_drvdata)
	{
	struct msm_priv *priv = domain->priv;
	struct msm_iommu_ctx_drvdata *ctx;

	list_for_each_entry(ctx, &priv->list_attached, attached_elm) {
	if (ctx->attached_domain == domain)
	break;
	}

	if (ctx->attached_domain != domain)
	return -EINVAL;

	*ctx_drvdata = ctx;
	*iommu_drvdata = dev_get_drvdata(ctx->pdev->dev.parent);
	return 0;
	}

	static int msm_iommu_map(struct iommu_domain *domain, unsigned long va,
	phys_addr_t pa, size_t len, int prot)
	{
	struct msm_iommu_drvdata *iommu_drvdata;
	struct msm_iommu_ctx_drvdata *ctx_drvdata;
	int ret = 0;

	mutex_lock(&msm_iommu_lock);

	ret = get_drvdata(domain, &iommu_drvdata, &ctx_drvdata);
	if (ret)
	goto fail;

	ret = msm_iommu_sec_ptbl_map(iommu_drvdata, ctx_drvdata,
	va, pa, len);
	fail:
	mutex_unlock(&msm_iommu_lock);
	return ret;
	}

	static size_t msm_iommu_unmap(struct iommu_domain *domain, unsigned long va,
	size_t len)
	{
	struct msm_iommu_drvdata *iommu_drvdata;
	struct msm_iommu_ctx_drvdata *ctx_drvdata;
	int ret = -ENODEV;

	mutex_lock(&msm_iommu_lock);

	ret = get_drvdata(domain, &iommu_drvdata, &ctx_drvdata);
	if (ret)
	goto fail;

	ret = msm_iommu_sec_ptbl_unmap(iommu_drvdata, ctx_drvdata,
	va, len);
	fail:
	mutex_unlock(&msm_iommu_lock);

	/* the IOMMU API requires us to return how many bytes were unmapped */
	len = ret ? 0 : len;
	return len;
	}

	static int msm_iommu_map_range(struct iommu_domain *domain, unsigned int va,
	struct scatterlist *sg, unsigned int len,
	int prot)
	{
	int ret;
	struct msm_iommu_drvdata *iommu_drvdata;
	struct msm_iommu_ctx_drvdata *ctx_drvdata;

	mutex_lock(&msm_iommu_lock);

	ret = get_drvdata(domain, &iommu_drvdata, &ctx_drvdata);
	if (ret)
	goto fail;
	ret = msm_iommu_sec_ptbl_map_range(iommu_drvdata, ctx_drvdata,
	va, sg, len);
	fail:
	mutex_unlock(&msm_iommu_lock);
	return ret;
	}


	static int msm_iommu_unmap_range(struct iommu_domain *domain, unsigned int va,
	unsigned int len)
	{
	struct msm_iommu_drvdata *iommu_drvdata;
	struct msm_iommu_ctx_drvdata *ctx_drvdata;
	int ret;

	mutex_lock(&msm_iommu_lock);

	ret = get_drvdata(domain, &iommu_drvdata, &ctx_drvdata);
	if (ret)
	goto fail;

	ret = msm_iommu_sec_ptbl_unmap(iommu_drvdata, ctx_drvdata, va, len);

	fail:
	mutex_unlock(&msm_iommu_lock);
	return 0;
	}

	static phys_addr_t msm_iommu_iova_to_phys(struct iommu_domain *domain,
	unsigned long va)
	{
	return 0;
	}

	static int msm_iommu_domain_has_cap(struct iommu_domain *domain,
	unsigned long cap)
	{
	return 0;
	}

	static phys_addr_t msm_iommu_get_pt_base_addr(struct iommu_domain *domain)
	{
	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,
	.map_range = msm_iommu_map_range,
	.unmap_range = msm_iommu_unmap_range,
	.iova_to_phys = msm_iommu_iova_to_phys,
	.domain_has_cap = msm_iommu_domain_has_cap,
	.get_pt_base_addr = msm_iommu_get_pt_base_addr,
	.pgsize_bitmap = MSM_IOMMU_PGSIZES,
	};

	static int __init msm_iommu_sec_init(void)
	{
	int ret;

	ret = bus_register(&msm_iommu_sec_bus_type);
	if (ret)
	goto fail;

	bus_set_iommu(&msm_iommu_sec_bus_type, &msm_iommu_ops);
	ret = msm_iommu_sec_ptbl_init();
	fail:
	return ret;
	}

	subsys_initcall(msm_iommu_sec_init);

	MODULE_LICENSE("GPL v2");
	MODULE_DESCRIPTION("MSM SMMU Secure Driver");