From: Jens Wiklander <jens.wiklan...@linaro.org>

Added new ioctl to allow users register own buffers as a shared memory.

Signed-off-by: Jens Wiklander <jens.wiklan...@linaro.org>
Signed-off-by: Volodymyr Babchuk <vlad.babc...@gmail.com>
---
 drivers/tee/tee_core.c   |  41 +++++++++-
 drivers/tee/tee_shm.c    | 205 +++++++++++++++++++++++++++++++++++++++++------
 include/linux/tee_drv.h  |  47 ++++++++++-
 include/uapi/linux/tee.h |  30 +++++++
 4 files changed, 293 insertions(+), 30 deletions(-)

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 58a5009..295910f 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -114,8 +114,6 @@ static int tee_ioctl_shm_alloc(struct tee_context *ctx,
        if (data.flags)
                return -EINVAL;
 
-       data.id = -1;
-
        shm = tee_shm_alloc(ctx, data.size, TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
        if (IS_ERR(shm))
                return PTR_ERR(shm);
@@ -138,6 +136,43 @@ static int tee_ioctl_shm_alloc(struct tee_context *ctx,
        return ret;
 }
 
+static int
+tee_ioctl_shm_register(struct tee_context *ctx,
+                      struct tee_ioctl_shm_register_data __user *udata)
+{
+       long ret;
+       struct tee_ioctl_shm_register_data data;
+       struct tee_shm *shm;
+
+       if (copy_from_user(&data, udata, sizeof(data)))
+               return -EFAULT;
+
+       /* Currently no input flags are supported */
+       if (data.flags)
+               return -EINVAL;
+
+       shm = tee_shm_register(ctx, data.addr, data.length,
+                              TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
+       if (IS_ERR(shm))
+               return PTR_ERR(shm);
+
+       data.id = shm->id;
+       data.flags = shm->flags;
+       data.length = shm->size;
+
+       if (copy_to_user(udata, &data, sizeof(data)))
+               ret = -EFAULT;
+       else
+               ret = tee_shm_get_fd(shm);
+       /*
+        * When user space closes the file descriptor the shared memory
+        * should be freed or if tee_shm_get_fd() failed then it will
+        * be freed immediately.
+        */
+       tee_shm_put(shm);
+       return ret;
+}
+
 static int params_from_user(struct tee_context *ctx, struct tee_param *params,
                            size_t num_params,
                            struct tee_ioctl_param __user *uparams)
@@ -586,6 +621,8 @@ static long tee_ioctl(struct file *filp, unsigned int cmd, 
unsigned long arg)
                return tee_ioctl_version(ctx, uarg);
        case TEE_IOC_SHM_ALLOC:
                return tee_ioctl_shm_alloc(ctx, uarg);
+       case TEE_IOC_SHM_REGISTER:
+               return tee_ioctl_shm_register(ctx, uarg);
        case TEE_IOC_OPEN_SESSION:
                return tee_ioctl_open_session(ctx, uarg);
        case TEE_IOC_INVOKE:
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index fdda89e..177e341 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -23,7 +23,6 @@
 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);
@@ -31,12 +30,29 @@ static void tee_shm_release(struct tee_shm *shm)
                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;
+       if (shm->flags & TEE_SHM_POOL) {
+               struct tee_shm_pool_mgr *poolm;
+
+               if (shm->flags & TEE_SHM_DMA_BUF)
+                       poolm = teedev->pool->dma_buf_mgr;
+               else
+                       poolm = teedev->pool->private_mgr;
+
+               poolm->ops->free(poolm, shm);
+       } else if (shm->flags & TEE_SHM_REGISTER) {
+               size_t n;
+               int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
+
+               if (rc)
+                       dev_err(teedev->dev.parent,
+                               "unregister shm %p failed: %d", shm, rc);
+
+               for (n = 0; n < shm->num_pages; n++)
+                       put_page(shm->pages[n]);
+
+               kfree(shm->pages);
+       }
 
-       poolm->ops->free(poolm, shm);
        kfree(shm);
 
        tee_device_put(teedev);
@@ -76,6 +92,10 @@ 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;
 
+       /* Refuse sharing shared memory provided by application */
+       if (shm->flags & TEE_SHM_REGISTER)
+               return -EINVAL;
+
        return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
                               size, vma->vm_page_prot);
 }
@@ -89,26 +109,20 @@ static const struct dma_buf_ops tee_shm_dma_buf_ops = {
        .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_shm *__tee_shm_alloc(struct tee_context *ctx,
+                               struct tee_device *teedev,
+                               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 (ctx && ctx->teedev != teedev) {
+               dev_err(teedev->dev.parent, "ctx and teedev mismatch\n");
+               return ERR_PTR(-EINVAL);
+       }
+
        if (!(flags & TEE_SHM_MAPPED)) {
                dev_err(teedev->dev.parent,
                        "only mapped allocations supported\n");
@@ -135,7 +149,7 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, 
size_t size, u32 flags)
                goto err_dev_put;
        }
 
-       shm->flags = flags;
+       shm->flags = flags | TEE_SHM_POOL;
        shm->teedev = teedev;
        shm->ctx = ctx;
        if (flags & TEE_SHM_DMA_BUF)
@@ -171,9 +185,12 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, 
size_t size, u32 flags)
                        goto err_rem;
                }
        }
-       mutex_lock(&teedev->mutex);
-       list_add_tail(&shm->link, &ctx->list_shm);
-       mutex_unlock(&teedev->mutex);
+
+       if (ctx) {
+               mutex_lock(&teedev->mutex);
+               list_add_tail(&shm->link, &ctx->list_shm);
+               mutex_unlock(&teedev->mutex);
+       }
 
        return shm;
 err_rem:
@@ -188,8 +205,139 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, 
size_t size, u32 flags)
        tee_device_put(teedev);
        return ret;
 }
+/**
+ * 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)
+{
+       return __tee_shm_alloc(ctx, ctx->teedev, size, flags);
+}
 EXPORT_SYMBOL_GPL(tee_shm_alloc);
 
+struct tee_shm *tee_shm_priv_alloc(struct tee_device *teedev, size_t size)
+{
+       return __tee_shm_alloc(NULL, teedev, size, TEE_SHM_MAPPED);
+}
+EXPORT_SYMBOL_GPL(tee_shm_priv_alloc);
+
+struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
+                                size_t length, u32 flags)
+{
+       struct tee_device *teedev = ctx->teedev;
+       const u32 req_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
+       struct tee_shm *shm;
+       void *ret;
+       int rc;
+       int num_pages;
+       unsigned long start;
+
+       if (flags != req_flags)
+               return ERR_PTR(-ENOTSUPP);
+
+       if (!tee_device_get(teedev))
+               return ERR_PTR(-EINVAL);
+
+       if (!teedev->desc->ops->shm_register ||
+           !teedev->desc->ops->shm_unregister) {
+               tee_device_put(teedev);
+               return ERR_PTR(-ENOTSUPP);
+       }
+
+       shm = kzalloc(sizeof(*shm), GFP_KERNEL);
+       if (!shm) {
+               ret = ERR_PTR(-ENOMEM);
+               goto err;
+       }
+
+       shm->flags = flags | TEE_SHM_REGISTER;
+       shm->teedev = teedev;
+       shm->ctx = ctx;
+       shm->id = -1;
+       start = rounddown(addr, PAGE_SIZE);
+       shm->offset = addr - start;
+       shm->size = length;
+       num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
+       shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
+       if (!shm->pages) {
+               ret = ERR_PTR(-ENOMEM);
+               goto err;
+       }
+
+       rc = get_user_pages_fast(start, num_pages, 1, shm->pages);
+       if (rc > 0)
+               shm->num_pages = rc;
+       if (rc != num_pages) {
+               if (rc > 0)
+                       rc = -ENOMEM;
+               ret = ERR_PTR(rc);
+               goto err;
+       }
+
+       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;
+       }
+
+       rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
+                                            shm->num_pages);
+       if (rc) {
+               ret = ERR_PTR(rc);
+               goto err;
+       }
+
+       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);
+                       teedev->desc->ops->shm_unregister(ctx, shm);
+                       goto err;
+               }
+       }
+
+       mutex_lock(&teedev->mutex);
+       list_add_tail(&shm->link, &ctx->list_shm);
+       mutex_unlock(&teedev->mutex);
+
+       return shm;
+err:
+       if (shm) {
+               size_t n;
+
+               if (shm->id >= 0) {
+                       mutex_lock(&teedev->mutex);
+                       idr_remove(&teedev->idr, shm->id);
+                       mutex_unlock(&teedev->mutex);
+               }
+               for (n = 0; n < shm->num_pages; n++)
+                       put_page(shm->pages[n]);
+               kfree(shm->pages);
+       }
+       kfree(shm);
+       tee_device_put(teedev);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(tee_shm_register);
+
 /**
  * tee_shm_get_fd() - Increase reference count and return file descriptor
  * @shm:       Shared memory handle
@@ -197,10 +345,9 @@ EXPORT_SYMBOL_GPL(tee_shm_alloc);
  */
 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)
+       if (!(shm->flags & TEE_SHM_DMA_BUF))
                return -EINVAL;
 
        fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
@@ -238,6 +385,8 @@ EXPORT_SYMBOL_GPL(tee_shm_free);
  */
 int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
 {
+       if (!(shm->flags & TEE_SHM_MAPPED))
+               return -EINVAL;
        /* Check that we're in the range of the shm */
        if ((char *)va < (char *)shm->kaddr)
                return -EINVAL;
@@ -258,6 +407,8 @@ EXPORT_SYMBOL_GPL(tee_shm_va2pa);
  */
 int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
 {
+       if (!(shm->flags & TEE_SHM_MAPPED))
+               return -EINVAL;
        /* Check that we're in the range of the shm */
        if (pa < shm->paddr)
                return -EINVAL;
@@ -284,6 +435,8 @@ EXPORT_SYMBOL_GPL(tee_shm_pa2va);
  */
 void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
 {
+       if (!(shm->flags & TEE_SHM_MAPPED))
+               return ERR_PTR(-EINVAL);
        if (offs >= shm->size)
                return ERR_PTR(-EINVAL);
        return (char *)shm->kaddr + offs;
diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index e9be4a4..70b9c73 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -25,8 +25,12 @@
  * specific TEE driver.
  */
 
-#define TEE_SHM_MAPPED         0x1     /* Memory mapped by the kernel */
-#define TEE_SHM_DMA_BUF                0x2     /* Memory with dma-buf handle */
+#define TEE_SHM_MAPPED         BIT(0)  /* Memory mapped by the kernel */
+#define TEE_SHM_DMA_BUF                BIT(1)  /* Memory with dma-buf handle */
+#define TEE_SHM_EXT_DMA_BUF    BIT(2)  /* Memory with dma-buf handle */
+#define TEE_SHM_REGISTER       BIT(3)  /* Memory registered in secure world */
+#define TEE_SHM_USER_MAPPED    BIT(4)  /* Memory mapped in user space */
+#define TEE_SHM_POOL           BIT(5)  /* Memory allocated from pool */
 
 struct device;
 struct tee_device;
@@ -76,6 +80,8 @@ struct tee_param {
  * @cancel_req:                request cancel of an ongoing invoke or open
  * @supp_revc:         called for supplicant to get a command
  * @supp_send:         called for supplicant to send a response
+ * @shm_register:      register shared memory buffer in TEE
+ * @shm_unregister:    unregister shared memory buffer in TEE
  */
 struct tee_driver_ops {
        void (*get_version)(struct tee_device *teedev,
@@ -94,6 +100,9 @@ struct tee_driver_ops {
                         struct tee_param *param);
        int (*supp_send)(struct tee_context *ctx, u32 ret, u32 num_params,
                         struct tee_param *param);
+       int (*shm_register)(struct tee_context *ctx, struct tee_shm *shm,
+                           struct page **pages, size_t num_pages);
+       int (*shm_unregister)(struct tee_context *ctx, struct tee_shm *shm);
 };
 
 /**
@@ -302,6 +311,30 @@ void *tee_get_drvdata(struct tee_device *teedev);
 struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags);
 
 /**
+ * tee_shm_priv_alloc() - Allocate shared memory privately
+ * @dev:       Device that allocates the shared memory
+ * @size:      Requested size of shared memory
+ *
+ * Allocates shared memory buffer that is not associated with any client
+ * context. Such buffers are owned by TEE driver and used for internal calls.
+ *
+ * @returns a pointer to 'struct tee_shm'
+ */
+struct tee_shm *tee_shm_priv_alloc(struct tee_device *teedev, size_t size);
+
+/**
+ * tee_shm_register() - Register shared memory buffer
+ * @ctx:       Context that registers the shared memory
+ * @addr:      Address is userspace of the shared buffer
+ * @length:    Length of the shared buffer
+ * @flags:     Flags setting properties for the requested shared memory.
+ *
+ * @returns a pointer to 'struct tee_shm'
+ */
+struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
+                                size_t length, u32 flags);
+
+/**
  * tee_shm_free() - Free shared memory
  * @shm:       Handle to shared memory to free
  */
@@ -366,4 +399,14 @@ int tee_shm_get_id(struct tee_shm *shm);
  */
 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id);
 
+/**
+ * tee_shm_is_registered() - Check if shared memory object in registered in TEE
+ * @shm:       Shared memory handle
+ * @returns true if object is registered in TEE
+ */
+static inline bool tee_shm_is_registered(struct tee_shm *shm)
+{
+       return shm && (shm->flags & TEE_SHM_REGISTER);
+}
+
 #endif /*__TEE_DRV_H*/
diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
index 688782e..d41a07a 100644
--- a/include/uapi/linux/tee.h
+++ b/include/uapi/linux/tee.h
@@ -50,6 +50,7 @@
 
 #define TEE_GEN_CAP_GP         (1 << 0)/* GlobalPlatform compliant TEE */
 #define TEE_GEN_CAP_PRIVILEGED (1 << 1)/* Privileged device (for supplicant) */
+#define TEE_GEN_CAP_REG_MEM    (1 << 2)/* Supports registering shared memory */
 
 /*
  * TEE Implementation ID
@@ -332,6 +333,35 @@ struct tee_iocl_supp_send_arg {
 #define TEE_IOC_SUPPL_SEND     _IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 7, \
                                     struct tee_ioctl_buf_data)
 
+/**
+ * struct tee_ioctl_shm_register_data - Shared memory register argument
+ * @addr:      [in] Start address of shared memory to register
+ * @length:    [in/out] Length of shared memory to register
+ * @flags:     [in/out] Flags to/from registration.
+ * @id:                [out] Identifier of the shared memory
+ *
+ * The flags field should currently be zero as input. Updated by the call
+ * with actual flags as defined by TEE_IOCTL_SHM_* above.
+ * This structure is used as argument for TEE_IOC_SHM_REGISTER below.
+ */
+struct tee_ioctl_shm_register_data {
+       __u64 addr;
+       __u64 length;
+       __u32 flags;
+       __s32 id;
+};
+
+/**
+ * TEE_IOC_SHM_REGISTER - Register shared memory argument
+ *
+ * Registers shared memory between the user space process and secure OS.
+ *
+ * Returns a file descriptor on success or < 0 on failure
+ *
+ * The shared memory is unregisterred when the descriptor is closed.
+ */
+#define TEE_IOC_SHM_REGISTER   _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 9, \
+                                    struct tee_ioctl_shm_register_data)
 /*
  * Five syscalls are used when communicating with the TEE driver.
  * open(): opens the device associated with the driver
-- 
2.7.4

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