drivers/tee/tee_shm.c - arm/linux - Git at Google

 /*
  * Copyright (c) 2015-2016, Linaro Limited
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * 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.
  *
  */
 #include <linux/device.h>
 #include <linux/dma-buf.h>
 #include <linux/fdtable.h>
 #include <linux/idr.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/tee_drv.h>
 #include "tee_private.h"

 static void tee_shm_release(struct tee_shm *shm)
 {
 	struct tee_device *teedev = shm->teedev;
 	struct tee_shm_pool_mgr *poolm;

 	mutex_lock(&teedev->mutex);
 	idr_remove(&teedev->idr, shm->id);
 	if (shm->ctx)
 		list_del(&shm->link);
 	mutex_unlock(&teedev->mutex);

 	if (shm->flags & TEE_SHM_DMA_BUF)
 		poolm = &teedev->pool->dma_buf_mgr;
 	else
 		poolm = &teedev->pool->private_mgr;

 	poolm->ops->free(poolm, shm);
 	kfree(shm);

 	tee_device_put(teedev);
 }

 static struct sg_table *tee_shm_op_map_dma_buf(struct dma_buf_attachment
 			*attach, enum dma_data_direction dir)
 {
 	return NULL;
 }

 static void tee_shm_op_unmap_dma_buf(struct dma_buf_attachment *attach,
 				     struct sg_table *table,
 				     enum dma_data_direction dir)
 {
 }

 static void tee_shm_op_release(struct dma_buf *dmabuf)
 {
 	struct tee_shm *shm = dmabuf->priv;

 	tee_shm_release(shm);
 }

 static void *tee_shm_op_map_atomic(struct dma_buf *dmabuf, unsigned long pgnum)
 {
 	return NULL;
 }

 static void *tee_shm_op_map(struct dma_buf *dmabuf, unsigned long pgnum)
 {
 	return NULL;
 }

 static int tee_shm_op_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
 {
 	struct tee_shm *shm = dmabuf->priv;
 	size_t size = vma->vm_end - vma->vm_start;

 	return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
 			       size, vma->vm_page_prot);
 }

 static const struct dma_buf_ops tee_shm_dma_buf_ops = {
 	.map_dma_buf = tee_shm_op_map_dma_buf,
 	.unmap_dma_buf = tee_shm_op_unmap_dma_buf,
 	.release = tee_shm_op_release,
 	.map_atomic = tee_shm_op_map_atomic,
 	.map = tee_shm_op_map,
 	.mmap = tee_shm_op_mmap,
 };

 /**
  * tee_shm_alloc() - Allocate shared memory
  * @ctx:	Context that allocates the shared memory
  * @size:	Requested size of shared memory
  * @flags:	Flags setting properties for the requested shared memory.
  *
  * Memory allocated as global shared memory is automatically freed when the
  * TEE file pointer is closed. The @flags field uses the bits defined by
  * TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
  * set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
  * associated with a dma-buf handle, else driver private memory.
  */
 struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
 {
 	struct tee_device *teedev = ctx->teedev;
 	struct tee_shm_pool_mgr *poolm = NULL;
 	struct tee_shm *shm;
 	void *ret;
 	int rc;

 	if (!(flags & TEE_SHM_MAPPED)) {
 		dev_err(teedev->dev.parent,
 			"only mapped allocations supported\n");
 		return ERR_PTR(-EINVAL);
 	}

 	if ((flags & ~(TEE_SHM_MAPPED | TEE_SHM_DMA_BUF))) {
 		dev_err(teedev->dev.parent, "invalid shm flags 0x%x", flags);
 		return ERR_PTR(-EINVAL);
 	}

 	if (!tee_device_get(teedev))
 		return ERR_PTR(-EINVAL);

 	if (!teedev->pool) {
 		/* teedev has been detached from driver */
 		ret = ERR_PTR(-EINVAL);
 		goto err_dev_put;
 	}

 	shm = kzalloc(sizeof(*shm), GFP_KERNEL);
 	if (!shm) {
 		ret = ERR_PTR(-ENOMEM);
 		goto err_dev_put;
 	}

 	shm->flags = flags;
 	shm->teedev = teedev;
 	shm->ctx = ctx;
 	if (flags & TEE_SHM_DMA_BUF)
 		poolm = &teedev->pool->dma_buf_mgr;
 	else
 		poolm = &teedev->pool->private_mgr;

 	rc = poolm->ops->alloc(poolm, shm, size);
 	if (rc) {
 		ret = ERR_PTR(rc);
 		goto err_kfree;
 	}

 	mutex_lock(&teedev->mutex);
 	shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
 	mutex_unlock(&teedev->mutex);
 	if (shm->id < 0) {
 		ret = ERR_PTR(shm->id);
 		goto err_pool_free;
 	}

 	if (flags & TEE_SHM_DMA_BUF) {
 		DEFINE_DMA_BUF_EXPORT_INFO(exp_info);

 		exp_info.ops = &tee_shm_dma_buf_ops;
 		exp_info.size = shm->size;
 		exp_info.flags = O_RDWR;
 		exp_info.priv = shm;

 		shm->dmabuf = dma_buf_export(&exp_info);
 		if (IS_ERR(shm->dmabuf)) {
 			ret = ERR_CAST(shm->dmabuf);
 			goto err_rem;
 		}
 	}
 	mutex_lock(&teedev->mutex);
 	list_add_tail(&shm->link, &ctx->list_shm);
 	mutex_unlock(&teedev->mutex);

 	return shm;
 err_rem:
 	mutex_lock(&teedev->mutex);
 	idr_remove(&teedev->idr, shm->id);
 	mutex_unlock(&teedev->mutex);
 err_pool_free:
 	poolm->ops->free(poolm, shm);
 err_kfree:
 	kfree(shm);
 err_dev_put:
 	tee_device_put(teedev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(tee_shm_alloc);

 /**
  * tee_shm_get_fd() - Increase reference count and return file descriptor
  * @shm:	Shared memory handle
  * @returns user space file descriptor to shared memory
  */
 int tee_shm_get_fd(struct tee_shm *shm)
 {
 	u32 req_flags = TEE_SHM_MAPPED | TEE_SHM_DMA_BUF;
 	int fd;

 	if ((shm->flags & req_flags) != req_flags)
 		return -EINVAL;

 	fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
 	if (fd >= 0)
 		get_dma_buf(shm->dmabuf);
 	return fd;
 }

 /**
  * tee_shm_free() - Free shared memory
  * @shm:	Handle to shared memory to free
  */
 void tee_shm_free(struct tee_shm *shm)
 {
 	/*
 	 * dma_buf_put() decreases the dmabuf reference counter and will
 	 * call tee_shm_release() when the last reference is gone.
 	 *
 	 * In the case of driver private memory we call tee_shm_release
 	 * directly instead as it doesn't have a reference counter.
 	 */
 	if (shm->flags & TEE_SHM_DMA_BUF)
 		dma_buf_put(shm->dmabuf);
 	else
 		tee_shm_release(shm);
 }
 EXPORT_SYMBOL_GPL(tee_shm_free);

 /**
  * tee_shm_va2pa() - Get physical address of a virtual address
  * @shm:	Shared memory handle
  * @va:		Virtual address to tranlsate
  * @pa:		Returned physical address
  * @returns 0 on success and < 0 on failure
  */
 int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
 {
 	/* Check that we're in the range of the shm */
 	if ((char *)va < (char *)shm->kaddr)
 		return -EINVAL;
 	if ((char *)va >= ((char *)shm->kaddr + shm->size))
 		return -EINVAL;

 	return tee_shm_get_pa(
 			shm, (unsigned long)va - (unsigned long)shm->kaddr, pa);
 }
 EXPORT_SYMBOL_GPL(tee_shm_va2pa);

 /**
  * tee_shm_pa2va() - Get virtual address of a physical address
  * @shm:	Shared memory handle
  * @pa:		Physical address to tranlsate
  * @va:		Returned virtual address
  * @returns 0 on success and < 0 on failure
  */
 int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
 {
 	/* Check that we're in the range of the shm */
 	if (pa < shm->paddr)
 		return -EINVAL;
 	if (pa >= (shm->paddr + shm->size))
 		return -EINVAL;

 	if (va) {
 		void *v = tee_shm_get_va(shm, pa - shm->paddr);

 		if (IS_ERR(v))
 			return PTR_ERR(v);
 		*va = v;
 	}
 	return 0;
 }
 EXPORT_SYMBOL_GPL(tee_shm_pa2va);

 /**
  * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
  * @shm:	Shared memory handle
  * @offs:	Offset from start of this shared memory
  * @returns virtual address of the shared memory + offs if offs is within
  *	the bounds of this shared memory, else an ERR_PTR
  */
 void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
 {
 	if (offs >= shm->size)
 		return ERR_PTR(-EINVAL);
 	return (char *)shm->kaddr + offs;
 }
 EXPORT_SYMBOL_GPL(tee_shm_get_va);

 /**
  * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
  * @shm:	Shared memory handle
  * @offs:	Offset from start of this shared memory
  * @pa:		Physical address to return
  * @returns 0 if offs is within the bounds of this shared memory, else an
  *	error code.
  */
 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
 {
 	if (offs >= shm->size)
 		return -EINVAL;
 	if (pa)
 		*pa = shm->paddr + offs;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(tee_shm_get_pa);

 /**
  * tee_shm_get_from_id() - Find shared memory object and increase reference
  * count
  * @ctx:	Context owning the shared memory
  * @id:		Id of shared memory object
  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
  */
 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
 {
 	struct tee_device *teedev;
 	struct tee_shm *shm;

 	if (!ctx)
 		return ERR_PTR(-EINVAL);

 	teedev = ctx->teedev;
 	mutex_lock(&teedev->mutex);
 	shm = idr_find(&teedev->idr, id);
 	if (!shm || shm->ctx != ctx)
 		shm = ERR_PTR(-EINVAL);
 	else if (shm->flags & TEE_SHM_DMA_BUF)
 		get_dma_buf(shm->dmabuf);
 	mutex_unlock(&teedev->mutex);
 	return shm;
 }
 EXPORT_SYMBOL_GPL(tee_shm_get_from_id);

 /**
  * tee_shm_get_id() - Get id of a shared memory object
  * @shm:	Shared memory handle
  * @returns id
  */
 int tee_shm_get_id(struct tee_shm *shm)
 {
 	return shm->id;
 }
 EXPORT_SYMBOL_GPL(tee_shm_get_id);

 /**
  * tee_shm_put() - Decrease reference count on a shared memory handle
  * @shm:	Shared memory handle
  */
 void tee_shm_put(struct tee_shm *shm)
 {
 	if (shm->flags & TEE_SHM_DMA_BUF)
 		dma_buf_put(shm->dmabuf);
 }
 EXPORT_SYMBOL_GPL(tee_shm_put);
	/*
	* Copyright (c) 2015-2016, Linaro Limited
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* 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.
	*
	*/
	#include <linux/device.h>
	#include <linux/dma-buf.h>
	#include <linux/fdtable.h>
	#include <linux/idr.h>
	#include <linux/sched.h>
	#include <linux/slab.h>
	#include <linux/tee_drv.h>
	#include "tee_private.h"

	static void tee_shm_release(struct tee_shm *shm)
	{
	struct tee_device *teedev = shm->teedev;
	struct tee_shm_pool_mgr *poolm;

	mutex_lock(&teedev->mutex);
	idr_remove(&teedev->idr, shm->id);
	if (shm->ctx)
	list_del(&shm->link);
	mutex_unlock(&teedev->mutex);

	if (shm->flags & TEE_SHM_DMA_BUF)
	poolm = &teedev->pool->dma_buf_mgr;
	else
	poolm = &teedev->pool->private_mgr;

	poolm->ops->free(poolm, shm);
	kfree(shm);

	tee_device_put(teedev);
	}

	static struct sg_table *tee_shm_op_map_dma_buf(struct dma_buf_attachment
	*attach, enum dma_data_direction dir)
	{
	return NULL;
	}

	static void tee_shm_op_unmap_dma_buf(struct dma_buf_attachment *attach,
	struct sg_table *table,
	enum dma_data_direction dir)
	{
	}

	static void tee_shm_op_release(struct dma_buf *dmabuf)
	{
	struct tee_shm *shm = dmabuf->priv;

	tee_shm_release(shm);
	}

	static void tee_shm_op_map_atomic(struct dma_buf dmabuf, unsigned long pgnum)
	{
	return NULL;
	}

	static void tee_shm_op_map(struct dma_buf dmabuf, unsigned long pgnum)
	{
	return NULL;
	}

	static int tee_shm_op_mmap(struct dma_buf dmabuf, struct vm_area_struct vma)
	{
	struct tee_shm *shm = dmabuf->priv;
	size_t size = vma->vm_end - vma->vm_start;

	return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
	size, vma->vm_page_prot);
	}

	static const struct dma_buf_ops tee_shm_dma_buf_ops = {
	.map_dma_buf = tee_shm_op_map_dma_buf,
	.unmap_dma_buf = tee_shm_op_unmap_dma_buf,
	.release = tee_shm_op_release,
	.map_atomic = tee_shm_op_map_atomic,
	.map = tee_shm_op_map,
	.mmap = tee_shm_op_mmap,
	};

	/**
	* tee_shm_alloc() - Allocate shared memory
	* @ctx: Context that allocates the shared memory
	* @size: Requested size of shared memory
	* @flags: Flags setting properties for the requested shared memory.
	*
	* Memory allocated as global shared memory is automatically freed when the
	* TEE file pointer is closed. The @flags field uses the bits defined by
	* TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
	* set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
	* associated with a dma-buf handle, else driver private memory.
	*/
	struct tee_shm tee_shm_alloc(struct tee_context ctx, size_t size, u32 flags)
	{
	struct tee_device *teedev = ctx->teedev;
	struct tee_shm_pool_mgr *poolm = NULL;
	struct tee_shm *shm;
	void *ret;
	int rc;

	if (!(flags & TEE_SHM_MAPPED)) {
	dev_err(teedev->dev.parent,
	"only mapped allocations supported\n");
	return ERR_PTR(-EINVAL);
	}

	if ((flags & ~(TEE_SHM_MAPPED \| TEE_SHM_DMA_BUF))) {
	dev_err(teedev->dev.parent, "invalid shm flags 0x%x", flags);
	return ERR_PTR(-EINVAL);
	}

	if (!tee_device_get(teedev))
	return ERR_PTR(-EINVAL);

	if (!teedev->pool) {
	/* teedev has been detached from driver */
	ret = ERR_PTR(-EINVAL);
	goto err_dev_put;
	}

	shm = kzalloc(sizeof(*shm), GFP_KERNEL);
	if (!shm) {
	ret = ERR_PTR(-ENOMEM);
	goto err_dev_put;
	}

	shm->flags = flags;
	shm->teedev = teedev;
	shm->ctx = ctx;
	if (flags & TEE_SHM_DMA_BUF)
	poolm = &teedev->pool->dma_buf_mgr;
	else
	poolm = &teedev->pool->private_mgr;

	rc = poolm->ops->alloc(poolm, shm, size);
	if (rc) {
	ret = ERR_PTR(rc);
	goto err_kfree;
	}

	mutex_lock(&teedev->mutex);
	shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
	mutex_unlock(&teedev->mutex);
	if (shm->id < 0) {
	ret = ERR_PTR(shm->id);
	goto err_pool_free;
	}

	if (flags & TEE_SHM_DMA_BUF) {
	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);

	exp_info.ops = &tee_shm_dma_buf_ops;
	exp_info.size = shm->size;
	exp_info.flags = O_RDWR;
	exp_info.priv = shm;

	shm->dmabuf = dma_buf_export(&exp_info);
	if (IS_ERR(shm->dmabuf)) {
	ret = ERR_CAST(shm->dmabuf);
	goto err_rem;
	}
	}
	mutex_lock(&teedev->mutex);
	list_add_tail(&shm->link, &ctx->list_shm);
	mutex_unlock(&teedev->mutex);

	return shm;
	err_rem:
	mutex_lock(&teedev->mutex);
	idr_remove(&teedev->idr, shm->id);
	mutex_unlock(&teedev->mutex);
	err_pool_free:
	poolm->ops->free(poolm, shm);
	err_kfree:
	kfree(shm);
	err_dev_put:
	tee_device_put(teedev);
	return ret;
	}
	EXPORT_SYMBOL_GPL(tee_shm_alloc);

	/**
	* tee_shm_get_fd() - Increase reference count and return file descriptor
	* @shm: Shared memory handle
	* @returns user space file descriptor to shared memory
	*/
	int tee_shm_get_fd(struct tee_shm *shm)
	{
	u32 req_flags = TEE_SHM_MAPPED \| TEE_SHM_DMA_BUF;
	int fd;

	if ((shm->flags & req_flags) != req_flags)
	return -EINVAL;

	fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
	if (fd >= 0)
	get_dma_buf(shm->dmabuf);
	return fd;
	}

	/**
	* tee_shm_free() - Free shared memory
	* @shm: Handle to shared memory to free
	*/
	void tee_shm_free(struct tee_shm *shm)
	{
	/*
	* dma_buf_put() decreases the dmabuf reference counter and will
	* call tee_shm_release() when the last reference is gone.
	*
	* In the case of driver private memory we call tee_shm_release
	* directly instead as it doesn't have a reference counter.
	*/
	if (shm->flags & TEE_SHM_DMA_BUF)
	dma_buf_put(shm->dmabuf);
	else
	tee_shm_release(shm);
	}
	EXPORT_SYMBOL_GPL(tee_shm_free);

	/**
	* tee_shm_va2pa() - Get physical address of a virtual address
	* @shm: Shared memory handle
	* @va: Virtual address to tranlsate
	* @pa: Returned physical address
	* @returns 0 on success and < 0 on failure
	*/
	int tee_shm_va2pa(struct tee_shm shm, void va, phys_addr_t *pa)
	{
	/* Check that we're in the range of the shm */
	if ((char )va < (char )shm->kaddr)
	return -EINVAL;
	if ((char )va >= ((char )shm->kaddr + shm->size))
	return -EINVAL;

	return tee_shm_get_pa(
	shm, (unsigned long)va - (unsigned long)shm->kaddr, pa);
	}
	EXPORT_SYMBOL_GPL(tee_shm_va2pa);

	/**
	* tee_shm_pa2va() - Get virtual address of a physical address
	* @shm: Shared memory handle
	* @pa: Physical address to tranlsate
	* @va: Returned virtual address
	* @returns 0 on success and < 0 on failure
	*/
	int tee_shm_pa2va(struct tee_shm shm, phys_addr_t pa, void *va)
	{
	/* Check that we're in the range of the shm */
	if (pa < shm->paddr)
	return -EINVAL;
	if (pa >= (shm->paddr + shm->size))
	return -EINVAL;

	if (va) {
	void *v = tee_shm_get_va(shm, pa - shm->paddr);

	if (IS_ERR(v))
	return PTR_ERR(v);
	*va = v;
	}
	return 0;
	}
	EXPORT_SYMBOL_GPL(tee_shm_pa2va);

	/**
	* tee_shm_get_va() - Get virtual address of a shared memory plus an offset
	* @shm: Shared memory handle
	* @offs: Offset from start of this shared memory
	* @returns virtual address of the shared memory + offs if offs is within
	* the bounds of this shared memory, else an ERR_PTR
	*/
	void tee_shm_get_va(struct tee_shm shm, size_t offs)
	{
	if (offs >= shm->size)
	return ERR_PTR(-EINVAL);
	return (char *)shm->kaddr + offs;
	}
	EXPORT_SYMBOL_GPL(tee_shm_get_va);

	/**
	* tee_shm_get_pa() - Get physical address of a shared memory plus an offset
	* @shm: Shared memory handle
	* @offs: Offset from start of this shared memory
	* @pa: Physical address to return
	* @returns 0 if offs is within the bounds of this shared memory, else an
	* error code.
	*/
	int tee_shm_get_pa(struct tee_shm shm, size_t offs, phys_addr_t pa)
	{
	if (offs >= shm->size)
	return -EINVAL;
	if (pa)
	*pa = shm->paddr + offs;
	return 0;
	}
	EXPORT_SYMBOL_GPL(tee_shm_get_pa);

	/**
	* tee_shm_get_from_id() - Find shared memory object and increase reference
	* count
	* @ctx: Context owning the shared memory
	* @id: Id of shared memory object
	* @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
	*/
	struct tee_shm tee_shm_get_from_id(struct tee_context ctx, int id)
	{
	struct tee_device *teedev;
	struct tee_shm *shm;

	if (!ctx)
	return ERR_PTR(-EINVAL);

	teedev = ctx->teedev;
	mutex_lock(&teedev->mutex);
	shm = idr_find(&teedev->idr, id);
	if (!shm \|\| shm->ctx != ctx)
	shm = ERR_PTR(-EINVAL);
	else if (shm->flags & TEE_SHM_DMA_BUF)
	get_dma_buf(shm->dmabuf);
	mutex_unlock(&teedev->mutex);
	return shm;
	}
	EXPORT_SYMBOL_GPL(tee_shm_get_from_id);

	/**
	* tee_shm_get_id() - Get id of a shared memory object
	* @shm: Shared memory handle
	* @returns id
	*/
	int tee_shm_get_id(struct tee_shm *shm)
	{
	return shm->id;
	}
	EXPORT_SYMBOL_GPL(tee_shm_get_id);

	/**
	* tee_shm_put() - Decrease reference count on a shared memory handle
	* @shm: Shared memory handle
	*/
	void tee_shm_put(struct tee_shm *shm)
	{
	if (shm->flags & TEE_SHM_DMA_BUF)
	dma_buf_put(shm->dmabuf);
	}
	EXPORT_SYMBOL_GPL(tee_shm_put);