amdccp.c revision 1.1.2.2
1 1.1.2.2 pgoyette /* $NetBSD: amdccp.c,v 1.1.2.2 2018/10/20 06:58:31 pgoyette Exp $ */ 2 1.1.2.2 pgoyette 3 1.1.2.2 pgoyette /* 4 1.1.2.2 pgoyette * Copyright (c) 2018 Jonathan A. Kollasch 5 1.1.2.2 pgoyette * All rights reserved. 6 1.1.2.2 pgoyette * 7 1.1.2.2 pgoyette * Redistribution and use in source and binary forms, with or without 8 1.1.2.2 pgoyette * modification, are permitted provided that the following conditions 9 1.1.2.2 pgoyette * are met: 10 1.1.2.2 pgoyette * 1. Redistributions of source code must retain the above copyright 11 1.1.2.2 pgoyette * notice, this list of conditions and the following disclaimer. 12 1.1.2.2 pgoyette * 2. Redistributions in binary form must reproduce the above copyright 13 1.1.2.2 pgoyette * notice, this list of conditions and the following disclaimer in the 14 1.1.2.2 pgoyette * documentation and/or other materials provided with the distribution. 15 1.1.2.2 pgoyette * 16 1.1.2.2 pgoyette * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 1.1.2.2 pgoyette * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 1.1.2.2 pgoyette * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 1.1.2.2 pgoyette * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 20 1.1.2.2 pgoyette * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 21 1.1.2.2 pgoyette * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 22 1.1.2.2 pgoyette * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 23 1.1.2.2 pgoyette * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 24 1.1.2.2 pgoyette * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 25 1.1.2.2 pgoyette * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 26 1.1.2.2 pgoyette * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 1.1.2.2 pgoyette */ 28 1.1.2.2 pgoyette 29 1.1.2.2 pgoyette #include <sys/cdefs.h> 30 1.1.2.2 pgoyette 31 1.1.2.2 pgoyette __KERNEL_RCSID(0, "$NetBSD: amdccp.c,v 1.1.2.2 2018/10/20 06:58:31 pgoyette Exp $"); 32 1.1.2.2 pgoyette 33 1.1.2.2 pgoyette #include <sys/param.h> 34 1.1.2.2 pgoyette #include <sys/systm.h> 35 1.1.2.2 pgoyette #include <sys/device.h> 36 1.1.2.2 pgoyette #include <sys/bus.h> 37 1.1.2.2 pgoyette #include <sys/rndpool.h> 38 1.1.2.2 pgoyette #include <sys/rndsource.h> 39 1.1.2.2 pgoyette 40 1.1.2.2 pgoyette #include <dev/ic/amdccpvar.h> 41 1.1.2.2 pgoyette 42 1.1.2.2 pgoyette static uint32_t amdccp_rnd_read(struct amdccp_softc *); 43 1.1.2.2 pgoyette static void amdccp_rnd_callback(size_t, void *); 44 1.1.2.2 pgoyette 45 1.1.2.2 pgoyette void 46 1.1.2.2 pgoyette amdccp_common_attach(struct amdccp_softc *sc) 47 1.1.2.2 pgoyette { 48 1.1.2.2 pgoyette mutex_init(&sc->sc_rndlock, MUTEX_DEFAULT, IPL_VM); 49 1.1.2.2 pgoyette rndsource_setcb(&sc->sc_rndsource, amdccp_rnd_callback, sc); 50 1.1.2.2 pgoyette rnd_attach_source(&sc->sc_rndsource, device_xname(sc->sc_dev), 51 1.1.2.2 pgoyette RND_TYPE_RNG, RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB); 52 1.1.2.2 pgoyette amdccp_rnd_callback(RND_POOLBITS / NBBY, sc); 53 1.1.2.2 pgoyette } 54 1.1.2.2 pgoyette 55 1.1.2.2 pgoyette static uint32_t 56 1.1.2.2 pgoyette amdccp_rnd_read(struct amdccp_softc *sc) 57 1.1.2.2 pgoyette { 58 1.1.2.2 pgoyette size_t retries = 5; 59 1.1.2.2 pgoyette uint32_t bits; 60 1.1.2.2 pgoyette 61 1.1.2.2 pgoyette /* TRNG register reads 0x0 when bits aren't valid */ 62 1.1.2.2 pgoyette while (retries--) { 63 1.1.2.2 pgoyette bits = bus_space_read_4(sc->sc_bst, sc->sc_bsh, CCP_TRNG_REG); 64 1.1.2.2 pgoyette if (bits != 0x0) 65 1.1.2.2 pgoyette break; 66 1.1.2.2 pgoyette } 67 1.1.2.2 pgoyette 68 1.1.2.2 pgoyette return bits; 69 1.1.2.2 pgoyette } 70 1.1.2.2 pgoyette 71 1.1.2.2 pgoyette static void 72 1.1.2.2 pgoyette amdccp_rnd_callback(size_t bytes_wanted, void *priv) 73 1.1.2.2 pgoyette { 74 1.1.2.2 pgoyette struct amdccp_softc * const sc = priv; 75 1.1.2.2 pgoyette uint32_t buf[128]; 76 1.1.2.2 pgoyette size_t cnt; 77 1.1.2.2 pgoyette 78 1.1.2.2 pgoyette mutex_enter(&sc->sc_rndlock); 79 1.1.2.2 pgoyette while (bytes_wanted) { 80 1.1.2.2 pgoyette const size_t nbytes = MIN(bytes_wanted, sizeof(buf)); 81 1.1.2.2 pgoyette const size_t nwords = howmany(nbytes, sizeof(buf[0])); 82 1.1.2.2 pgoyette for (cnt = 0; cnt < nwords; cnt++) { 83 1.1.2.2 pgoyette buf[cnt] = amdccp_rnd_read(sc); 84 1.1.2.2 pgoyette if (buf[cnt] == 0) { 85 1.1.2.2 pgoyette break; 86 1.1.2.2 pgoyette } 87 1.1.2.2 pgoyette } 88 1.1.2.2 pgoyette const size_t cntby = cnt * sizeof(buf[0]); 89 1.1.2.2 pgoyette rnd_add_data_sync(&sc->sc_rndsource, buf, cntby, cntby * NBBY); 90 1.1.2.2 pgoyette bytes_wanted -= MIN(bytes_wanted, cntby); 91 1.1.2.2 pgoyette } 92 1.1.2.2 pgoyette explicit_memset(buf, 0, sizeof(buf)); 93 1.1.2.2 pgoyette mutex_exit(&sc->sc_rndlock); 94 1.1.2.2 pgoyette } 95
Indexes created Mon Oct 13 01:09:56 GMT 2025