1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * Driver for Qualcomm Secure Execution Environment (SEE) interface (QSEECOM). 4 * Responsible for setting up and managing QSEECOM client devices. 5 * 6 * Copyright (C) 2023 Maximilian Luz <luzmaximilian@gmail.com> 7 */ 8 9 #ifndef __QCOM_QSEECOM_H 10 #define __QCOM_QSEECOM_H 11 12 #include <linux/auxiliary_bus.h> 13 #include <linux/dma-mapping.h> 14 #include <linux/types.h> 15 16 #include <linux/firmware/qcom/qcom_scm.h> 17 18 /** 19 * struct qseecom_client - QSEECOM client device. 20 * @aux_dev: Underlying auxiliary device. 21 * @app_id: ID of the loaded application. 22 */ 23 struct qseecom_client { 24 struct auxiliary_device aux_dev; 25 u32 app_id; 26 }; 27 28 /** 29 * qseecom_scm_dev() - Get the SCM device associated with the QSEECOM client. 30 * @client: The QSEECOM client device. 31 * 32 * Returns the SCM device under which the provided QSEECOM client device 33 * operates. This function is intended to be used for DMA allocations. 34 */ 35 static inline struct device *qseecom_scm_dev(struct qseecom_client *client) 36 { 37 return client->aux_dev.dev.parent->parent; 38 } 39 40 /** 41 * qseecom_dma_alloc() - Allocate DMA memory for a QSEECOM client. 42 * @client: The QSEECOM client to allocate the memory for. 43 * @size: The number of bytes to allocate. 44 * @dma_handle: Pointer to where the DMA address should be stored. 45 * @gfp: Allocation flags. 46 * 47 * Wrapper function for dma_alloc_coherent(), allocating DMA memory usable for 48 * TZ/QSEECOM communication. Refer to dma_alloc_coherent() for details. 49 */ 50 static inline void *qseecom_dma_alloc(struct qseecom_client *client, size_t size, 51 dma_addr_t *dma_handle, gfp_t gfp) 52 { 53 return dma_alloc_coherent(qseecom_scm_dev(client), size, dma_handle, gfp); 54 } 55 56 /** 57 * dma_free_coherent() - Free QSEECOM DMA memory. 58 * @client: The QSEECOM client for which the memory has been allocated. 59 * @size: The number of bytes allocated. 60 * @cpu_addr: Virtual memory address to free. 61 * @dma_handle: DMA memory address to free. 62 * 63 * Wrapper function for dma_free_coherent(), freeing memory previously 64 * allocated with qseecom_dma_alloc(). Refer to dma_free_coherent() for 65 * details. 66 */ 67 static inline void qseecom_dma_free(struct qseecom_client *client, size_t size, 68 void *cpu_addr, dma_addr_t dma_handle) 69 { 70 return dma_free_coherent(qseecom_scm_dev(client), size, cpu_addr, dma_handle); 71 } 72 73 /** 74 * qcom_qseecom_app_send() - Send to and receive data from a given QSEE app. 75 * @client: The QSEECOM client associated with the target app. 76 * @req: Request buffer sent to the app (must be TZ memory). 77 * @req_size: Size of the request buffer. 78 * @rsp: Response buffer, written to by the app (must be TZ memory). 79 * @rsp_size: Size of the response buffer. 80 * 81 * Sends a request to the QSEE app associated with the given client and read 82 * back its response. The caller must provide two DMA memory regions, one for 83 * the request and one for the response, and fill out the @req region with the 84 * respective (app-specific) request data. The QSEE app reads this and returns 85 * its response in the @rsp region. 86 * 87 * Note: This is a convenience wrapper around qcom_scm_qseecom_app_send(). 88 * Clients should prefer to use this wrapper. 89 * 90 * Return: Zero on success, nonzero on failure. 91 */ 92 static inline int qcom_qseecom_app_send(struct qseecom_client *client, 93 void *req, size_t req_size, 94 void *rsp, size_t rsp_size) 95 { 96 return qcom_scm_qseecom_app_send(client->app_id, req, req_size, rsp, rsp_size); 97 } 98 99 #endif /* __QCOM_QSEECOM_H */ 100
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