Author: stepan Date: 2009-08-12 11:27:45 +0200 (Wed, 12 Aug 2009) New Revision: 677
Modified: trunk/chipset_enable.c trunk/flash.h trunk/physmap.c Log: Fix up MSR handling in flashrom to support more OSes than Linux. Signed-off-by: Stefan Reinauer stepan@coresystems.de Acked-by: Carl-Daniel Hailfinger c-d.hailfinger.devel.2006@gmx.net
Modified: trunk/chipset_enable.c =================================================================== --- trunk/chipset_enable.c 2009-08-11 12:15:39 UTC (rev 676) +++ trunk/chipset_enable.c 2009-08-12 09:27:45 UTC (rev 677) @@ -2,7 +2,7 @@ * This file is part of the flashrom project. * * Copyright (C) 2000 Silicon Integrated System Corporation - * Copyright (C) 2005-2009 coresystems GmbH stepan@coresystems.de + * Copyright (C) 2005-2009 coresystems GmbH * Copyright (C) 2006 Uwe Hermann uwe@hermann-uwe.de * * This program is free software; you can redistribute it and/or modify @@ -527,92 +527,36 @@
/** * Geode systems write protect the BIOS via RCONFs (cache settings similar - * to MTRRs). To unlock, change MSR 0x1808 top byte to 0x22. Reading and - * writing to MSRs, however requires instructions rdmsr/wrmsr, which are - * ring0 privileged instructions so only the kernel can do the read/write. - * This function, therefore, requires that the msr kernel module be loaded - * to access these instructions from user space using device /dev/cpu/0/msr. + * to MTRRs). To unlock, change MSR 0x1808 top byte to 0x22. * - * This hard-coded location could have potential problems on SMP machines - * since it assumes cpu0, but it is safe on the Geode which is not SMP. - * * Geode systems also write protect the NOR flash chip itself via MSR_NORF_CTL. * To enable write to NOR Boot flash for the benefit of systems that have such * a setup, raise MSR 0x51400018 WE_CS3 (write enable Boot Flash Chip Select). - * - * This is probably not portable beyond Linux. */ static int enable_flash_cs5536(struct pci_dev *dev, const char *name) { #define MSR_RCONF_DEFAULT 0x1808 #define MSR_NORF_CTL 0x51400018
- int fd_msr; - unsigned char buf[8]; + msr_t msr;
- fd_msr = open("/dev/cpu/0/msr", O_RDWR); - if (fd_msr == -1) { - perror("open(/dev/cpu/0/msr)"); - printf("Cannot operate on MSR. Did you run 'modprobe msr'?\n"); + /* Geode only has a single core */ + if (setup_cpu_msr(0)) return -1; - }
- if (lseek64(fd_msr, (off64_t) MSR_RCONF_DEFAULT, SEEK_SET) == -1) { - perror("lseek64"); - close(fd_msr); - return -1; + msr = rdmsr(MSR_RCONF_DEFAULT); + if ((msr.hi >> 24) != 0x22) { + msr.hi &= 0xfbffffff; + wrmsr(MSR_RCONF_DEFAULT, msr); }
- if (read(fd_msr, buf, 8) != 8) { - perror("read msr"); - close(fd_msr); - return -1; - } - - if (buf[7] != 0x22) { - buf[7] &= 0xfb; - if (lseek64(fd_msr, (off64_t) MSR_RCONF_DEFAULT, - SEEK_SET) == -1) { - perror("lseek64"); - close(fd_msr); - return -1; - } - - if (write(fd_msr, buf, 8) < 0) { - perror("msr write"); - close(fd_msr); - return -1; - } - } - - if (lseek64(fd_msr, (off64_t) MSR_NORF_CTL, SEEK_SET) == -1) { - perror("lseek64"); - close(fd_msr); - return -1; - } - - if (read(fd_msr, buf, 8) != 8) { - perror("read msr"); - close(fd_msr); - return -1; - } - + msr = rdmsr(MSR_NORF_CTL); /* Raise WE_CS3 bit. */ - buf[0] |= 0x08; + msr.lo |= 0x08; + wrmsr(MSR_NORF_CTL, msr);
- if (lseek64(fd_msr, (off64_t) MSR_NORF_CTL, SEEK_SET) == -1) { - perror("lseek64"); - close(fd_msr); - return -1; - } - if (write(fd_msr, buf, 8) < 0) { - perror("msr write"); - close(fd_msr); - return -1; - } + cleanup_cpu_msr();
- close(fd_msr); - #undef MSR_RCONF_DEFAULT #undef MSR_NORF_CTL return 0;
Modified: trunk/flash.h =================================================================== --- trunk/flash.h 2009-08-11 12:15:39 UTC (rev 676) +++ trunk/flash.h 2009-08-12 09:27:45 UTC (rev 677) @@ -3,7 +3,7 @@ * * Copyright (C) 2000 Silicon Integrated System Corporation * Copyright (C) 2000 Ronald G. Minnich rminnich@gmail.com - * Copyright (C) 2005-2007 coresystems GmbH stepan@coresystems.de + * Copyright (C) 2005-2009 coresystems GmbH * Copyright (C) 2006-2009 Carl-Daniel Hailfinger * * This program is free software; you can redistribute it and/or modify @@ -301,6 +301,13 @@ /* physmap.c */ void *physmap(const char *descr, unsigned long phys_addr, size_t len); void physunmap(void *virt_addr, size_t len); +int setup_cpu_msr(int cpu); +void cleanup_cpu_msr(void); +#ifndef __DARWIN__ +typedef struct { uint32_t hi, lo; } msr_t; +msr_t rdmsr(int addr); +int wrmsr(int addr, msr_t msr); +#endif
/* internal.c */ struct pci_dev *pci_dev_find_filter(struct pci_filter filter);
Modified: trunk/physmap.c =================================================================== --- trunk/physmap.c 2009-08-11 12:15:39 UTC (rev 676) +++ trunk/physmap.c 2009-08-12 09:27:45 UTC (rev 677) @@ -2,6 +2,7 @@ * This file is part of the flashrom project. * * Copyright (C) 2009 Peter Stuge peter@stuge.se + * Copyright (C) 2009 coresystems 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 @@ -21,6 +22,7 @@ #include <sys/stat.h> #include <fcntl.h> #include <stdlib.h> +#include <string.h> #include <errno.h> #include "flash.h"
@@ -117,3 +119,136 @@
return virt_addr; } + +#ifdef __linux__ +/* + * Reading and writing to MSRs, however requires instructions rdmsr/wrmsr, + * which are ring0 privileged instructions so only the kernel can do the + * read/write. This function, therefore, requires that the msr kernel module + * be loaded to access these instructions from user space using device + * /dev/cpu/0/msr. + */ + +static int fd_msr = -1; + +msr_t rdmsr(int addr) +{ + uint8_t buf[8]; + msr_t msr = { 0xffffffff, 0xffffffff }; + + if (lseek(fd_msr, (off_t) addr, SEEK_SET) == -1) { + perror("Could not lseek() to MSR"); + close(fd_msr); + exit(1); + } + + if (read(fd_msr, buf, 8) == 8) { + msr.lo = *(uint32_t *)buf; + msr.hi = *(uint32_t *)(buf + 4); + + return msr; + } + + if (errno != EIO) { + // A severe error. + perror("Could not read() MSR"); + close(fd_msr); + exit(1); + } + + return msr; +} + +int wrmsr(int addr, msr_t msr) +{ + if (lseek(fd_msr, (off_t) addr, SEEK_SET) == -1) { + perror("Could not lseek() to MSR"); + close(fd_msr); + exit(1); + } + + if (write(fd_msr, &msr, 8) != 8 && errno != EIO) { + perror("Could not write() MSR"); + close(fd_msr); + exit(1); + } + + /* some MSRs must not be written */ + if (errno == EIO) + return -1; + + return 0; +} + +int setup_cpu_msr(int cpu) +{ + char msrfilename[64]; + memset(msrfilename, 0, 64); + sprintf(msrfilename, "/dev/cpu/%d/msr", cpu); + + if (fd_msr != -1) { + printf("MSR was already initialized\n"); + return -1; + } + + fd_msr = open(msrfilename, O_RDWR); + + if (fd_msr < 0) { + perror("Error while opening /dev/cpu/0/msr"); + printf("Did you run 'modprobe msr'?\n"); + return -1; + } + + return 0; +} + +void cleanup_cpu_msr(void) +{ + if (fd_msr == -1) { + printf("No MSR initialized.\n"); + return; + } + + close(fd_msr); + + /* Clear MSR file descriptor */ + fd_msr = -1; +} +#else +#ifdef __DARWIN__ +int setup_cpu_msr(int cpu) +{ + // Always succeed for now + return 0; +} + +void cleanup_cpu_msr(void) +{ + // Nothing, yet. +} +#else +msr_t rdmsr(int addr) +{ + msr_t ret = { 0xffffffff, 0xffffffff }; + + return ret; +} + +int wrmsr(int addr, msr_t msr) +{ + return -1; +} + +int setup_cpu_msr(int cpu) +{ + printf("No MSR support for your OS yet.\n"); + return -1; +} + +void cleanup_cpu_msr(void) +{ + // Nothing, yet. +} +#endif +#endif +