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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | // SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause /* * Copyright (c) 2024, Max Resch */ #include <dm.h> #include <malloc.h> #include <rng.h> #include <asm/dma-mapping.h> #include <asm/types.h> #include <mach/mbox.h> /* size of entropy buffer */ #define RNG_BUFFER_SIZE 128U struct turris_rwtm_rng_priv { phys_addr_t buffer; }; static int turris_rwtm_rng_fill_entropy(phys_addr_t entropy, size_t size) { u32 args[3] = { 1, (u32)entropy, size }; int ret; /* flush data cache */ flush_dcache_range(entropy, entropy + size); /* * get entropy * args[0] = 1 copies BYTES array in args[1] of length args[2] */ ret = mbox_do_cmd(MBOX_CMD_GET_RANDOM, args, 3, NULL, 0); if (ret < 0) return ret; /* invalidate data cache */ invalidate_dcache_range(entropy, entropy + size); return 0; } static int turris_rwtm_rng_random_read(struct udevice *dev, void *data, size_t count) { struct turris_rwtm_rng_priv *priv = dev_get_priv(dev); phys_addr_t phys; size_t size; int ret; phys = priv->buffer; while (count) { size = min_t(size_t, RNG_BUFFER_SIZE, count); ret = turris_rwtm_rng_fill_entropy(phys, size); if (ret < 0) return ret; memcpy(data, (void *)phys, size); count -= size; data = (u8 *)data + size; } return 0; } static int turris_rwtm_rng_probe(struct udevice *dev) { struct turris_rwtm_rng_priv *priv = dev_get_priv(dev); u32 args[] = { 0 }; int ret; /* * check if the random command is supported * args[0] = 0 would copy 16 DWORDS entropy to out but we ignore them */ ret = mbox_do_cmd(MBOX_CMD_GET_RANDOM, args, ARRAY_SIZE(args), NULL, 0); if (ret < 0) return ret; /* entropy buffer */ priv->buffer = 0; /* buffer address need to be aligned */ dma_alloc_coherent(RNG_BUFFER_SIZE, (unsigned long *)&priv->buffer); if (!priv->buffer) return -ENOMEM; return 0; } static int turris_rwtm_rng_remove(struct udevice *dev) { struct turris_rwtm_rng_priv *priv = dev_get_priv(dev); phys_addr_t phys = priv->buffer; dma_free_coherent((void *)phys); return 0; } static const struct dm_rng_ops turris_rwtm_rng_ops = { .read = turris_rwtm_rng_random_read, }; /* * only Turris MOX firmware has the RNG but allow all probable devices to be * probed the default firmware will just reject the probe */ static const struct udevice_id turris_rwtm_rng_match[] = { { .compatible = "cznic,turris-mox-rwtm" }, { .compatible = "marvell,armada-3700-rwtm-firmware" }, {}, }; U_BOOT_DRIVER(turris_rwtm_rng) = { .name = "turris-rwtm-rng", .id = UCLASS_RNG, .of_match = turris_rwtm_rng_match, .ops = &turris_rwtm_rng_ops, .probe = turris_rwtm_rng_probe, .remove = turris_rwtm_rng_remove, .priv_auto = sizeof(struct turris_rwtm_rng_priv), }; |