From bd4bcab8addf8791a9100140ae963415450b9663 Mon Sep 17 00:00:00 2001 From: Patrick Rudolph Date: Sun, 30 Jun 2019 22:12:15 +0200 Subject: [PATCH] lib: Rewrite qemu-armv7 ramdetect * Move armv7 RAM dection to a common place * Enable it for all emulated platforms * Use 32bit probe values and restore memory even on failure * Use the new logic on the following boards: ** qemu-armv7 ** qemu-riscv Tested on qemu-system-riscv: Fixes kernel panic due to wrong memory limits reported. Change-Id: I37386c6a95bfc3b7b25aeae32c6e14cff9913513 Signed-off-by: Patrick Rudolph Reviewed-on: https://review.coreboot.org/c/coreboot/+/33934 Tested-by: build bot (Jenkins) Reviewed-by: Angel Pons --- .../mainboard.h => include/ramdetect.h} | 21 +++-- src/lib/Makefile.inc | 3 + src/lib/ramdetect.c | 78 +++++++++++++++++++ src/mainboard/emulation/qemu-armv7/Kconfig | 4 + src/mainboard/emulation/qemu-armv7/cbmem.c | 48 +----------- .../emulation/qemu-armv7/mainboard.c | 5 +- .../emulation/qemu-riscv/mainboard.c | 6 +- src/soc/ucb/riscv/cbmem.c | 12 +-- 8 files changed, 108 insertions(+), 69 deletions(-) rename src/{mainboard/emulation/qemu-armv7/mainboard.h => include/ramdetect.h} (53%) create mode 100644 src/lib/ramdetect.c diff --git a/src/mainboard/emulation/qemu-armv7/mainboard.h b/src/include/ramdetect.h similarity index 53% rename from src/mainboard/emulation/qemu-armv7/mainboard.h rename to src/include/ramdetect.h index 87fa3beee6..b63cdf14cf 100644 --- a/src/mainboard/emulation/qemu-armv7/mainboard.h +++ b/src/include/ramdetect.h @@ -1,12 +1,9 @@ /* * This file is part of the coreboot project. * - * Copyright (C) 2016 Vladimir Serbinenko - * * 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 - * the Free Software Foundation; version 2 or, at your option, any later - * version of the License. + * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of @@ -14,10 +11,12 @@ * GNU General Public License for more details. */ -#ifndef QEMU_ARMV7_MAINBOARD_H -#define QEMU_ARMV7_MAINBOARD_H - -/* Returns RAM size in mebibytes. */ -int probe_ramsize(void); - -#endif +/* + * Probe an area if it's read/writable. + * Primary use case is the detection of DRAM amount on emulators. + * + * @param dram_start Physical address of DRAM start + * @param probe_size Maximum size in MiB to probe for + * @return The detected DRAM size in MiB + */ +size_t probe_ramsize(const uintptr_t dram_start, const size_t probe_size); diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc index 7492b162dc..9deb5bf377 100644 --- a/src/lib/Makefile.inc +++ b/src/lib/Makefile.inc @@ -65,6 +65,7 @@ verstage-$(CONFIG_CONSOLE_CBMEM) += cbmem_console.c verstage-$(CONFIG_GENERIC_UDELAY) += timer.c verstage-$(CONFIG_GENERIC_GPIO_LIB) += gpio.c +romstage-$(CONFIG_VENDOR_EMULATION) += ramdetect.c romstage-y += prog_loaders.c romstage-y += prog_ops.c romstage-y += memchr.c @@ -105,6 +106,7 @@ endif romstage-$(CONFIG_GENERIC_UDELAY) += timer.c +ramstage-$(CONFIG_VENDOR_EMULATION) += ramdetect.c ramstage-y += prog_loaders.c ramstage-y += prog_ops.c ramstage-y += hardwaremain.c @@ -155,6 +157,7 @@ ramstage-y += cbmem_common.c ramstage-y += imd_cbmem.c ramstage-y += imd.c +postcar-$(CONFIG_VENDOR_EMULATION) += ramdetect.c postcar-y += cbmem_common.c postcar-$(CONFIG_CONSOLE_CBMEM) += cbmem_console.c postcar-y += imd_cbmem.c diff --git a/src/lib/ramdetect.c b/src/lib/ramdetect.c new file mode 100644 index 0000000000..5416a580dd --- /dev/null +++ b/src/lib/ramdetect.c @@ -0,0 +1,78 @@ +/* + * This file is part of the coreboot project. + * + * 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 + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include + +#define OVERLAP(a, b, s, e) ((b) > (s) && (a) < (e)) + +static int probe_mb(const uintptr_t dram_start, const uintptr_t size) +{ + uintptr_t addr = dram_start + (size * MiB) - sizeof(uint32_t); + static const uint32_t patterns[] = { + 0x55aa55aa, + 0x12345678 + }; + void *ptr = (void *) addr; + size_t i; + + /* Don't accidentally clober oneself. */ + if (OVERLAP(addr, addr + sizeof(uint32_t), (uintptr_t)_program, (uintptr_t) _eprogram)) + return 1; + + uint32_t old = read32(ptr); + for (i = 0; i < ARRAY_SIZE(patterns); i++) { + write32(ptr, patterns[i]); + if (read32(ptr) != patterns[i]) + break; + } + + write32(ptr, old); + return i == ARRAY_SIZE(patterns); +} + +/* - 20 as probe_size is in MiB, - 1 as i is signed */ +#define MAX_ADDRESSABLE_SPACE (sizeof(size_t) * 8 - 20 - 1) + +/* Probe an area if it's read/writable. */ +size_t probe_ramsize(const uintptr_t dram_start, const size_t probe_size) +{ + ssize_t i; + size_t msb = 0; + size_t discovered = 0; + + static size_t saved_result; + if (saved_result) + return saved_result; + + /* Find the MSB + 1. */ + size_t tmp = probe_size; + do { + msb++; + } while (tmp >>= 1); + + /* Limit search to accessible address space */ + msb = MIN(msb, MAX_ADDRESSABLE_SPACE); + + /* Compact binary search. */ + for (i = msb; i >= 0; i--) + if (probe_mb(dram_start, (discovered | (1ULL << i)))) + discovered |= (1ULL << i); + + saved_result = discovered; + printk(BIOS_DEBUG, "RAMDETECT: Found %zu MiB RAM\n", discovered); + return discovered; +} diff --git a/src/mainboard/emulation/qemu-armv7/Kconfig b/src/mainboard/emulation/qemu-armv7/Kconfig index fc770cf27d..73b2d5dede 100644 --- a/src/mainboard/emulation/qemu-armv7/Kconfig +++ b/src/mainboard/emulation/qemu-armv7/Kconfig @@ -53,4 +53,8 @@ config MAINBOARD_VENDOR string default "ARM Ltd." +config DRAM_SIZE_MB + int + default 1024 + endif # BOARD_EMULATION_QEMU_ARMV7 diff --git a/src/mainboard/emulation/qemu-armv7/cbmem.c b/src/mainboard/emulation/qemu-armv7/cbmem.c index 927bd42d54..542e08d05e 100644 --- a/src/mainboard/emulation/qemu-armv7/cbmem.c +++ b/src/mainboard/emulation/qemu-armv7/cbmem.c @@ -11,55 +11,11 @@ * GNU General Public License for more details. */ -#include #include #include -#include -#include "mainboard.h" - -#define PATTERN1 0x55 -#define PATTERN2 0xaa - -/* Returns 1 if mebibyte mb is present and 0 otherwise. */ -static int probe_mb(int mb) -{ - char *ptr = (char *) 0x60000000 + (mb << 20) + 0xfffff; - char old; - if (ptr < (char *) &_eprogram) { - /* Don't probe below _end to avoid accidentally clobering - oneself. */ - return 1; - } - - old = read8(ptr); - write8(ptr, PATTERN1); - if (read8(ptr) != PATTERN1) - return 0; - write8(ptr, PATTERN2); - if (read8(ptr) != PATTERN2) - return 0; - write8(ptr, old); - return 1; -} - -int probe_ramsize(void) -{ - int i; - int discovered = 0; - static int saved_result; - if (saved_result) - return saved_result; - /* Compact binary search. */ - /* 1 GiB is the largest supported RAM by this machine. */ - for (i = 9; i >= 0; i--) - if (probe_mb(discovered | (1 << i))) - discovered |= (1 << i); - discovered++; - saved_result = discovered; - return discovered; -} +#include void *cbmem_top(void) { - return _dram + (probe_ramsize() << 20); + return _dram + (probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB) * MiB); } diff --git a/src/mainboard/emulation/qemu-armv7/mainboard.c b/src/mainboard/emulation/qemu-armv7/mainboard.c index cc14dd8e7b..338cff9321 100644 --- a/src/mainboard/emulation/qemu-armv7/mainboard.c +++ b/src/mainboard/emulation/qemu-armv7/mainboard.c @@ -18,9 +18,10 @@ #include #include #include -#include "mainboard.h" #include #include +#include +#include static void init_gfx(void) { @@ -57,7 +58,7 @@ static void mainboard_enable(struct device *dev) halt(); } - discovered = probe_ramsize(); + discovered = probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB); printk(BIOS_DEBUG, "%d MiB of RAM discovered\n", discovered); ram_resource(dev, 0, 0x60000000 >> 10, discovered << 10); cbmem_recovery(0); diff --git a/src/mainboard/emulation/qemu-riscv/mainboard.c b/src/mainboard/emulation/qemu-riscv/mainboard.c index 4b428aa486..02356aa70e 100644 --- a/src/mainboard/emulation/qemu-riscv/mainboard.c +++ b/src/mainboard/emulation/qemu-riscv/mainboard.c @@ -17,15 +17,19 @@ #include #include #include +#include static void mainboard_enable(struct device *dev) { + size_t dram_mb_detected; if (!dev) { die("No dev0; die\n"); } - ram_resource(dev, 0, (uintptr_t)_dram / KiB, CONFIG_DRAM_SIZE_MB * KiB); + dram_mb_detected = probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB); + ram_resource(dev, 0, (uintptr_t)_dram / KiB, dram_mb_detected / KiB); + cbmem_recovery(0); } diff --git a/src/soc/ucb/riscv/cbmem.c b/src/soc/ucb/riscv/cbmem.c index 2ee400ab8b..542e08d05e 100644 --- a/src/soc/ucb/riscv/cbmem.c +++ b/src/soc/ucb/riscv/cbmem.c @@ -12,16 +12,10 @@ */ #include +#include +#include void *cbmem_top(void) { - uintptr_t base; - size_t size; - - /* Use dummy values until we can query the memory size again */ - //query_mem(configstring(), &base, &size); - base = 0x80000000; - size = 128 * MiB; - - return (void *)(base + size); + return _dram + (probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB) * MiB); }