linux/drivers/tee/tee_shm.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015-2017, 2019-2021 Linaro Limited
 */
#include <linux/anon_inodes.h>
#include <linux/device.h>
#include <linux/idr.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/tee_core.h>
#include <linux/uaccess.h>
#include <linux/uio.h>
#include <linux/highmem.h>
#include "tee_private.h"

static void shm_put_kernel_pages(struct page **pages, size_t page_count)
{ … }

static void shm_get_kernel_pages(struct page **pages, size_t page_count)
{ … }

static void release_registered_pages(struct tee_shm *shm)
{ … }

static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
{ … }

static struct tee_shm *shm_alloc_helper(struct tee_context *ctx, size_t size,
					size_t align, u32 flags, int id)
{ … }

/**
 * tee_shm_alloc_user_buf() - Allocate shared memory for user space
 * @ctx:	Context that allocates the shared memory
 * @size:	Requested size of shared memory
 *
 * Memory allocated as user space shared memory is automatically freed when
 * the TEE file pointer is closed. The primary usage of this function is
 * when the TEE driver doesn't support registering ordinary user space
 * memory.
 *
 * @returns a pointer to 'struct tee_shm'
 */
struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size)
{ … }

/**
 * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer
 * @ctx:	Context that allocates the shared memory
 * @size:	Requested size of shared memory
 *
 * The returned memory registered in secure world and is suitable to be
 * passed as a memory buffer in parameter argument to
 * tee_client_invoke_func(). The memory allocated is later freed with a
 * call to tee_shm_free().
 *
 * @returns a pointer to 'struct tee_shm'
 */
struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
 *			      kernel buffer
 * @ctx:	Context that allocates the shared memory
 * @size:	Requested size of shared memory
 *
 * This function returns similar shared memory as
 * tee_shm_alloc_kernel_buf(), but with the difference that the memory
 * might not be registered in secure world in case the driver supports
 * passing memory not registered in advance.
 *
 * This function should normally only be used internally in the TEE
 * drivers.
 *
 * @returns a pointer to 'struct tee_shm'
 */
struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
{ … }
EXPORT_SYMBOL_GPL(…);

int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
			     int (*shm_register)(struct tee_context *ctx,
						 struct tee_shm *shm,
						 struct page **pages,
						 size_t num_pages,
						 unsigned long start))
{ … }
EXPORT_SYMBOL_GPL(…);

void tee_dyn_shm_free_helper(struct tee_shm *shm,
			     int (*shm_unregister)(struct tee_context *ctx,
						   struct tee_shm *shm))
{ … }
EXPORT_SYMBOL_GPL(…);

static struct tee_shm *
register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags,
		    int id)
{ … }

/**
 * tee_shm_register_user_buf() - Register a userspace shared memory buffer
 * @ctx:	Context that registers the shared memory
 * @addr:	The userspace address of the shared buffer
 * @length:	Length of the shared buffer
 *
 * @returns a pointer to 'struct tee_shm'
 */
struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
					  unsigned long addr, size_t length)
{ … }

/**
 * tee_shm_register_kernel_buf() - Register kernel memory to be shared with
 *				   secure world
 * @ctx:	Context that registers the shared memory
 * @addr:	The buffer
 * @length:	Length of the buffer
 *
 * @returns a pointer to 'struct tee_shm'
 */

struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
					    void *addr, size_t length)
{ … }
EXPORT_SYMBOL_GPL(…);

static int tee_shm_fop_release(struct inode *inode, struct file *filp)
{ … }

static int tee_shm_fop_mmap(struct file *filp, struct vm_area_struct *vma)
{ … }

static const struct file_operations tee_shm_fops = …;

/**
 * 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)
{ … }

/**
 * tee_shm_free() - Free shared memory
 * @shm:	Handle to shared memory to free
 */
void tee_shm_free(struct tee_shm *shm)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * tee_shm_put() - Decrease reference count on a shared memory handle
 * @shm:	Shared memory handle
 */
void tee_shm_put(struct tee_shm *shm)
{ … }
EXPORT_SYMBOL_GPL(…);