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authorJens Wiklander <jens.wiklander@linaro.org>2015-03-11 16:39:39 +0300
committerJens Wiklander <jens.wiklander@linaro.org>2017-03-09 17:42:33 +0300
commit967c9cca2cc50569efc65945325c173cecba83bd (patch)
treecf64178161ee3ba1cb18762604b82f2df7738c33 /drivers/tee/tee_shm.c
parentc8bfafb1594435889b571b79325011e8b7fd087b (diff)
downloadlinux-967c9cca2cc50569efc65945325c173cecba83bd.tar.xz
tee: generic TEE subsystem
Initial patch for generic TEE subsystem. This subsystem provides: * Registration/un-registration of TEE drivers. * Shared memory between normal world and secure world. * Ioctl interface for interaction with user space. * Sysfs implementation_id of TEE driver A TEE (Trusted Execution Environment) driver is a driver that interfaces with a trusted OS running in some secure environment, for example, TrustZone on ARM cpus, or a separate secure co-processor etc. The TEE subsystem can serve a TEE driver for a Global Platform compliant TEE, but it's not limited to only Global Platform TEEs. This patch builds on other similar implementations trying to solve the same problem: * "optee_linuxdriver" by among others Jean-michel DELORME<jean-michel.delorme@st.com> and Emmanuel MICHEL <emmanuel.michel@st.com> * "Generic TrustZone Driver" by Javier González <javier@javigon.com> Acked-by: Andreas Dannenberg <dannenberg@ti.com> Tested-by: Jerome Forissier <jerome.forissier@linaro.org> (HiKey) Tested-by: Volodymyr Babchuk <vlad.babchuk@gmail.com> (RCAR H3) Tested-by: Scott Branden <scott.branden@broadcom.com> Reviewed-by: Javier González <javier@javigon.com> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Diffstat (limited to 'drivers/tee/tee_shm.c')
-rw-r--r--drivers/tee/tee_shm.c358
1 files changed, 358 insertions, 0 deletions
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
new file mode 100644
index 000000000000..0be1e3e93bee
--- /dev/null
+++ b/drivers/tee/tee_shm.c
@@ -0,0 +1,358 @@
+/*
+ * 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_kmap_atomic(struct dma_buf *dmabuf, unsigned long pgnum)
+{
+ return NULL;
+}
+
+static void *tee_shm_op_kmap(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 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,
+ .kmap_atomic = tee_shm_op_kmap_atomic,
+ .kmap = tee_shm_op_kmap,
+ .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);