Manish V Badarkhe | cc2c743 | 2022-02-24 20:22:39 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2022 Arm Limited. All rights reserved. |
| 3 | * |
| 4 | * SPDX-License-Identifier: BSD-3-Clause |
| 5 | * |
| 6 | * DRTM DMA protection. |
| 7 | * |
| 8 | * Authors: |
| 9 | * Lucian Paul-Trifu <lucian.paultrifu@gmail.com> |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <stdint.h> |
| 14 | #include <string.h> |
| 15 | |
| 16 | #include <common/debug.h> |
| 17 | |
| 18 | #include "drtm_dma_prot.h" |
| 19 | #include <plat/common/platform.h> |
| 20 | |
| 21 | /* |
| 22 | * This function checks that platform supports complete DMA protection. |
| 23 | * and returns false - if the platform supports complete DMA protection. |
| 24 | * and returns true - if the platform does not support complete DMA protection. |
| 25 | */ |
| 26 | bool drtm_dma_prot_init(void) |
| 27 | { |
| 28 | bool must_init_fail = false; |
| 29 | const uintptr_t *smmus; |
| 30 | size_t num_smmus = 0; |
| 31 | unsigned int total_smmus; |
| 32 | |
| 33 | /* Warns presence of non-host platforms */ |
| 34 | if (plat_has_non_host_platforms()) { |
| 35 | WARN("DRTM: the platform includes trusted DMA-capable devices" |
| 36 | " (non-host platforms)\n"); |
| 37 | } |
| 38 | |
| 39 | /* |
| 40 | * DLME protection is uncertain on platforms with peripherals whose |
| 41 | * DMA is not managed by an SMMU. DRTM doesn't work on such platforms. |
| 42 | */ |
| 43 | if (plat_has_unmanaged_dma_peripherals()) { |
| 44 | ERROR("DRTM: this platform does not provide DMA protection\n"); |
| 45 | must_init_fail = true; |
| 46 | } |
| 47 | |
| 48 | /* |
| 49 | * Check that the platform reported all SMMUs. |
| 50 | * It is acceptable if the platform doesn't have any SMMUs when it |
| 51 | * doesn't have any DMA-capable devices. |
| 52 | */ |
| 53 | total_smmus = plat_get_total_smmus(); |
| 54 | plat_enumerate_smmus(&smmus, &num_smmus); |
| 55 | if (num_smmus != total_smmus) { |
| 56 | ERROR("DRTM: could not discover all SMMUs\n"); |
| 57 | must_init_fail = true; |
| 58 | } |
| 59 | |
| 60 | return must_init_fail; |
| 61 | } |