diff options
Diffstat (limited to 'drivers/tee/qcomtee/async.c')
| -rw-r--r-- | drivers/tee/qcomtee/async.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/drivers/tee/qcomtee/async.c b/drivers/tee/qcomtee/async.c new file mode 100644 index 000000000000..31bff4309e67 --- /dev/null +++ b/drivers/tee/qcomtee/async.c @@ -0,0 +1,182 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include "qcomtee.h" + +#define QCOMTEE_ASYNC_VERSION_1_0 0x00010000U /* Maj: 0x0001, Min: 0x0000. */ +#define QCOMTEE_ASYNC_VERSION_1_1 0x00010001U /* Maj: 0x0001, Min: 0x0001. */ +#define QCOMTEE_ASYNC_VERSION_1_2 0x00010002U /* Maj: 0x0001, Min: 0x0002. */ +#define QCOMTEE_ASYNC_VERSION_CURRENT QCOMTEE_ASYNC_VERSION_1_2 + +#define QCOMTEE_ASYNC_VERSION_MAJOR(n) upper_16_bits(n) +#define QCOMTEE_ASYNC_VERSION_MINOR(n) lower_16_bits(n) + +#define QCOMTEE_ASYNC_VERSION_CURRENT_MAJOR \ + QCOMTEE_ASYNC_VERSION_MAJOR(QCOMTEE_ASYNC_VERSION_CURRENT) +#define QCOMTEE_ASYNC_VERSION_CURRENT_MINOR \ + QCOMTEE_ASYNC_VERSION_MINOR(QCOMTEE_ASYNC_VERSION_CURRENT) + +/** + * struct qcomtee_async_msg_hdr - Asynchronous message header format. + * @version: current async protocol version of the remote endpoint. + * @op: async operation. + * + * @version specifies the endpoint's (QTEE or driver) supported async protocol. + * For example, if QTEE sets @version to %QCOMTEE_ASYNC_VERSION_1_1, QTEE + * handles operations supported in %QCOMTEE_ASYNC_VERSION_1_1 or + * %QCOMTEE_ASYNC_VERSION_1_0. @op determines the message format. + */ +struct qcomtee_async_msg_hdr { + u32 version; + u32 op; +}; + +/* Size of an empty async message. */ +#define QCOMTEE_ASYNC_MSG_ZERO sizeof(struct qcomtee_async_msg_hdr) + +/** + * struct qcomtee_async_release_msg - Release asynchronous message. + * @hdr: message header as &struct qcomtee_async_msg_hdr. + * @counts: number of objects in @object_ids. + * @object_ids: array of object IDs that should be released. + * + * Available in Maj = 0x0001, Min >= 0x0000. + */ +struct qcomtee_async_release_msg { + struct qcomtee_async_msg_hdr hdr; + u32 counts; + u32 object_ids[] __counted_by(counts); +}; + +/** + * qcomtee_get_async_buffer() - Get the start of the asynchronous message. + * @oic: context used for the current invocation. + * @async_buffer: return buffer to extract from or fill in async messages. + * + * If @oic is used for direct object invocation, the whole outbound buffer + * is available for the async message. If @oic is used for a callback request, + * the tail of the outbound buffer (after the callback request message) is + * available for the async message. + * + * The start of the async buffer is aligned, see qcomtee_msg_offset_align(). + */ +static void qcomtee_get_async_buffer(struct qcomtee_object_invoke_ctx *oic, + struct qcomtee_buffer *async_buffer) +{ + struct qcomtee_msg_callback *msg; + unsigned int offset; + int i; + + if (!(oic->flags & QCOMTEE_OIC_FLAG_BUSY)) { + /* The outbound buffer is empty. Using the whole buffer. */ + offset = 0; + } else { + msg = (struct qcomtee_msg_callback *)oic->out_msg.addr; + + /* Start offset in a message for buffer arguments. */ + offset = qcomtee_msg_buffer_args(struct qcomtee_msg_callback, + qcomtee_msg_args(msg)); + + /* Add size of IB arguments. */ + qcomtee_msg_for_each_input_buffer(i, msg) + offset += qcomtee_msg_offset_align(msg->args[i].b.size); + + /* Add size of OB arguments. */ + qcomtee_msg_for_each_output_buffer(i, msg) + offset += qcomtee_msg_offset_align(msg->args[i].b.size); + } + + async_buffer->addr = oic->out_msg.addr + offset; + async_buffer->size = oic->out_msg.size - offset; +} + +/** + * async_release() - Process QTEE async release requests. + * @oic: context used for the current invocation. + * @msg: async message for object release. + * @size: size of the async buffer available. + * + * Return: Size of the outbound buffer used when processing @msg. + */ +static size_t async_release(struct qcomtee_object_invoke_ctx *oic, + struct qcomtee_async_msg_hdr *async_msg, + size_t size) +{ + struct qcomtee_async_release_msg *msg; + struct qcomtee_object *object; + int i; + + msg = (struct qcomtee_async_release_msg *)async_msg; + + for (i = 0; i < msg->counts; i++) { + object = qcomtee_idx_erase(oic, msg->object_ids[i]); + qcomtee_object_put(object); + } + + return struct_size(msg, object_ids, msg->counts); +} + +/** + * qcomtee_fetch_async_reqs() - Fetch and process asynchronous messages. + * @oic: context used for the current invocation. + * + * Calls handlers to process the requested operations in the async message. + * Currently, only supports async release requests. + */ +void qcomtee_fetch_async_reqs(struct qcomtee_object_invoke_ctx *oic) +{ + struct qcomtee_async_msg_hdr *async_msg; + struct qcomtee_buffer async_buffer; + size_t consumed, used = 0; + u16 major_ver; + + qcomtee_get_async_buffer(oic, &async_buffer); + + while (async_buffer.size - used > QCOMTEE_ASYNC_MSG_ZERO) { + async_msg = (struct qcomtee_async_msg_hdr *)(async_buffer.addr + + used); + /* + * QTEE assumes that the unused space of the async buffer is + * zeroed; so if version is zero, the buffer is unused. + */ + if (async_msg->version == 0) + goto out; + + major_ver = QCOMTEE_ASYNC_VERSION_MAJOR(async_msg->version); + /* Major version mismatch is a compatibility break. */ + if (major_ver != QCOMTEE_ASYNC_VERSION_CURRENT_MAJOR) { + pr_err("Async message version mismatch (%u != %u)\n", + major_ver, QCOMTEE_ASYNC_VERSION_CURRENT_MAJOR); + + goto out; + } + + switch (async_msg->op) { + case QCOMTEE_MSG_OBJECT_OP_RELEASE: + consumed = async_release(oic, async_msg, + async_buffer.size - used); + break; + default: + pr_err("Unsupported async message %u\n", async_msg->op); + goto out; + } + + /* Supported operation but unable to parse the message. */ + if (!consumed) { + pr_err("Unable to parse async message for op %u\n", + async_msg->op); + goto out; + } + + /* Next async message. */ + used += qcomtee_msg_offset_align(consumed); + } + +out: + /* Reset the async buffer so async requests do not loop to QTEE. */ + memzero_explicit(async_buffer.addr, async_buffer.size); +} |