From 6220f8d8338a17b0af5dde5d99d890fba7660cfe Mon Sep 17 00:00:00 2001 From: Patrick Rudolph Date: Fri, 22 Feb 2019 12:06:41 +0100 Subject: soc/cavium/cn81xx: Enable RNG for DRAM init MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The Cavium DRAM init might use the RNG for pattern generation. Initialize it before running DRAM init. Tested on OpenCellular Elgon. The RNG generates non identical numbers. Change-Id: I886f920e9941793fb76b56cc5a24a42e23b082e0 Signed-off-by: Patrick Rudolph Reviewed-on: https://review.coreboot.org/c/31567 Tested-by: build bot (Jenkins) Reviewed-by: Kyösti Mälkki --- src/soc/cavium/cn81xx/sdram.c | 46 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/src/soc/cavium/cn81xx/sdram.c b/src/soc/cavium/cn81xx/sdram.c index 2342b049ef..05546cc9b1 100644 --- a/src/soc/cavium/cn81xx/sdram.c +++ b/src/soc/cavium/cn81xx/sdram.c @@ -3,6 +3,7 @@ * * Copyright 2018 Facebook, Inc. * Copyright 2003-2017 Cavium Inc. + * Copyright 2019 9elements Agency GmbH * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -28,17 +29,61 @@ #include #include #include +#include +#include +#include size_t sdram_size_mb(void) { return bdk_dram_get_size_mbytes(0); } +#define BDK_RNM_CTL_STATUS 0 +#define BDK_RNM_RANDOM 0x100000 + +#if ENV_ROMSTAGE +/* Enable RNG for DRAM init */ +static void rnm_init(void) +{ + /* Bus numbers are hardcoded in ASIC. No need to program bridges. */ + pci_devfn_t dev = PCI_DEV(2, 0, 0); + + u64 *bar = (u64 *)ecam0_get_bar_val(dev, 0); + if (!bar) { + printk(BIOS_ERR, "RNG: Failed to get BAR0\n"); + return; + } + + printk(BIOS_DEBUG, "RNG: BAR0 at %p\n", bar); + + u64 reg = read64(&bar[BDK_RNM_CTL_STATUS]); + /* + * Enables the output of the RNG. + * Entropy enable for random number generator. + */ + reg |= 3; + write64(&bar[BDK_RNM_CTL_STATUS], reg); + + /* Read back after enable so we know it is done. */ + reg = read64(&bar[BDK_RNM_CTL_STATUS]); + /* + * Errata (RNM-22528) First consecutive reads to RNM_RANDOM return same + * value. Before using the random entropy, read RNM_RANDOM at least once + * and discard the data + */ + reg = read64(&bar[BDK_RNM_RANDOM]); + printk(BIOS_SPEW, "RNG: RANDOM %llx\n", reg); + reg = read64(&bar[BDK_RNM_RANDOM]); + printk(BIOS_SPEW, "RNG: RANDOM %llx\n", reg); +} + /* based on bdk_boot_dram() */ void sdram_init(void) { printk(BIOS_DEBUG, "Initializing DRAM\n"); + rnm_init(); + /** * FIXME: second arg is actually a desired frequency if set (the * function usually obtains frequency via the config). That might @@ -100,3 +145,4 @@ void sdram_init(void) printk(BIOS_INFO, "SDRAM initialization finished.\n"); } +#endif -- cgit v1.2.3