diff options
Diffstat (limited to 'drivers/sfi/sfi_core.c')
| -rw-r--r-- | drivers/sfi/sfi_core.c | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/drivers/sfi/sfi_core.c b/drivers/sfi/sfi_core.c new file mode 100644 index 0000000..d3b4968 --- /dev/null +++ b/drivers/sfi/sfi_core.c @@ -0,0 +1,407 @@ +/* sfi_core.c Simple Firmware Interface - core internals */ + +/* + + This file is provided under a dual BSD/GPLv2 license. When using or + redistributing this file, you may do so under either license. + + GPL LICENSE SUMMARY + + Copyright(c) 2009 Intel Corporation. All rights reserved. + + This program is free software; you can redistribute it and/or modify + it under the terms of version 2 of the GNU General Public License as + published by the Free Software Foundation. + + 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. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + The full GNU General Public License is included in this distribution + in the file called LICENSE.GPL. + + BSD LICENSE + + Copyright(c) 2009 Intel Corporation. All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in + the documentation and/or other materials provided with the + distribution. + * Neither the name of Intel Corporation nor the names of its + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +*/ + +#define KMSG_COMPONENT "SFI" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/bootmem.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/acpi.h> +#include <linux/init.h> +#include <linux/sfi.h> + +#include "sfi_core.h" + +#define ON_SAME_PAGE(addr1, addr2) \ + (((unsigned long)(addr1) & PAGE_MASK) == \ + ((unsigned long)(addr2) & PAGE_MASK)) +#define TABLE_ON_PAGE(page, table, size) (ON_SAME_PAGE(page, table) && \ + ON_SAME_PAGE(page, table + size)) + +int sfi_disabled __read_mostly; +EXPORT_SYMBOL(sfi_disabled); + +static u64 syst_pa __read_mostly; +static struct sfi_table_simple *syst_va __read_mostly; + +/* + * FW creates and saves the SFI tables in memory. When these tables get + * used, they may need to be mapped to virtual address space, and the mapping + * can happen before or after the ioremap() is ready, so a flag is needed + * to indicating this + */ +static u32 sfi_use_ioremap __read_mostly; + +static void __iomem *sfi_map_memory(u64 phys, u32 size) +{ + if (!phys || !size) + return NULL; + + if (sfi_use_ioremap) + return ioremap(phys, size); + else + return early_ioremap(phys, size); +} + +static void sfi_unmap_memory(void __iomem *virt, u32 size) +{ + if (!virt || !size) + return; + + if (sfi_use_ioremap) + iounmap(virt); + else + early_iounmap(virt, size); +} + +static void sfi_print_table_header(unsigned long long pa, + struct sfi_table_header *header) +{ + pr_info("%4.4s %llX, %04X (v%d %6.6s %8.8s)\n", + header->sig, pa, + header->len, header->rev, header->oem_id, + header->oem_table_id); +} + +/* + * sfi_verify_table() + * Sanity check table lengh, calculate checksum + */ +static __init int sfi_verify_table(struct sfi_table_header *table) +{ + + u8 checksum = 0; + u8 *puchar = (u8 *)table; + u32 length = table->len; + + /* Sanity check table length against arbitrary 1MB limit */ + if (length > 0x100000) { + pr_err("Invalid table length 0x%x\n", length); + return -1; + } + + while (length--) + checksum += *puchar++; + + if (checksum) { + pr_err("Checksum %2.2X should be %2.2X\n", + table->csum, table->csum - checksum); + return -1; + } + return 0; +} + +/* + * sfi_map_table() + * + * Return address of mapped table + * Check for common case that we can re-use mapping to SYST, + * which requires syst_pa, syst_va to be initialized. + */ +struct sfi_table_header *sfi_map_table(u64 pa) +{ + struct sfi_table_header *th; + u32 length; + + if (!TABLE_ON_PAGE(syst_pa, pa, sizeof(struct sfi_table_header))) + th = sfi_map_memory(pa, sizeof(struct sfi_table_header)); + else + th = (void *)syst_va + (pa - syst_pa); + + /* If table fits on same page as its header, we are done */ + if (TABLE_ON_PAGE(th, th, th->len)) + return th; + + /* Entire table does not fit on same page as SYST */ + length = th->len; + if (!TABLE_ON_PAGE(syst_pa, pa, sizeof(struct sfi_table_header))) + sfi_unmap_memory(th, sizeof(struct sfi_table_header)); + + return sfi_map_memory(pa, length); +} + +/* + * sfi_unmap_table() + * + * Undoes effect of sfi_map_table() by unmapping table + * if it did not completely fit on same page as SYST. + */ +void sfi_unmap_table(struct sfi_table_header *th) +{ + if (!TABLE_ON_PAGE(syst_va, th, th->len)) + sfi_unmap_memory(th, TABLE_ON_PAGE(th, th, th->len) ? + sizeof(*th) : th->len); +} + +static int sfi_table_check_key(struct sfi_table_header *th, + struct sfi_table_key *key) +{ + + if (strncmp(th->sig, key->sig, SFI_SIGNATURE_SIZE) + || (key->oem_id && strncmp(th->oem_id, + key->oem_id, SFI_OEM_ID_SIZE)) + || (key->oem_table_id && strncmp(th->oem_table_id, + key->oem_table_id, SFI_OEM_TABLE_ID_SIZE))) + return -1; + + return 0; +} + +/* + * This function will be used in 2 cases: + * 1. used to enumerate and verify the tables addressed by SYST/XSDT, + * thus no signature will be given (in kernel boot phase) + * 2. used to parse one specific table, signature must exist, and + * the mapped virt address will be returned, and the virt space + * will be released by call sfi_put_table() later + * + * Return value: + * NULL: when can't find a table matching the key + * ERR_PTR(error): error value + * virt table address: when a matched table is found + */ +struct sfi_table_header *sfi_check_table(u64 pa, struct sfi_table_key *key) +{ + struct sfi_table_header *th; + void *ret = NULL; + + th = sfi_map_table(pa); + if (!th) + return ERR_PTR(-ENOMEM); + + if (!key->sig) { + sfi_print_table_header(pa, th); + if (sfi_verify_table(th)) + ret = ERR_PTR(-EINVAL); + } else { + if (!sfi_table_check_key(th, key)) + return th; /* Success */ + } + + sfi_unmap_table(th); + return ret; +} + +/* + * sfi_get_table() + * + * Search SYST for the specified table with the signature in + * the key, and return the mapped table + */ +struct sfi_table_header *sfi_get_table(struct sfi_table_key *key) +{ + struct sfi_table_header *th; + u32 tbl_cnt, i; + + tbl_cnt = SFI_GET_NUM_ENTRIES(syst_va, u64); + for (i = 0; i < tbl_cnt; i++) { + th = sfi_check_table(syst_va->pentry[i], key); + if (!IS_ERR(th) && th) + return th; + } + + return NULL; +} + +void sfi_put_table(struct sfi_table_header *th) +{ + sfi_unmap_table(th); +} + +/* Find table with signature, run handler on it */ +int sfi_table_parse(char *signature, char *oem_id, char *oem_table_id, + sfi_table_handler handler) +{ + struct sfi_table_header *table = NULL; + struct sfi_table_key key; + int ret = -EINVAL; + + if (sfi_disabled || !handler || !signature) + goto exit; + + key.sig = signature; + key.oem_id = oem_id; + key.oem_table_id = oem_table_id; + + table = sfi_get_table(&key); + if (!table) + goto exit; + + ret = handler(table); + sfi_put_table(table); +exit: + return ret; +} +EXPORT_SYMBOL_GPL(sfi_table_parse); + +/* + * sfi_parse_syst() + * Checksum all the tables in SYST and print their headers + * + * success: set syst_va, return 0 + */ +static int __init sfi_parse_syst(void) +{ + struct sfi_table_key key = SFI_ANY_KEY; + int tbl_cnt, i; + void *ret; + + syst_va = sfi_map_memory(syst_pa, sizeof(struct sfi_table_simple)); + if (!syst_va) + return -ENOMEM; + + tbl_cnt = SFI_GET_NUM_ENTRIES(syst_va, u64); + for (i = 0; i < tbl_cnt; i++) { + ret = sfi_check_table(syst_va->pentry[i], &key); + if (IS_ERR(ret)) + return PTR_ERR(ret); + } + + return 0; +} + +/* + * The OS finds the System Table by searching 16-byte boundaries between + * physical address 0x000E0000 and 0x000FFFFF. The OS shall search this region + * starting at the low address and shall stop searching when the 1st valid SFI + * System Table is found. + * + * success: set syst_pa, return 0 + * fail: return -1 + */ +static __init int sfi_find_syst(void) +{ + unsigned long offset, len; + void *start; + + len = SFI_SYST_SEARCH_END - SFI_SYST_SEARCH_BEGIN; + start = sfi_map_memory(SFI_SYST_SEARCH_BEGIN, len); + if (!start) + return -1; + + for (offset = 0; offset < len; offset += 16) { + struct sfi_table_header *syst_hdr; + + syst_hdr = start + offset; + if (strncmp(syst_hdr->sig, SFI_SIG_SYST, + SFI_SIGNATURE_SIZE)) + continue; + + if (syst_hdr->len > PAGE_SIZE) + continue; + + sfi_print_table_header(SFI_SYST_SEARCH_BEGIN + offset, + syst_hdr); + + if (sfi_verify_table(syst_hdr)) + continue; + + /* + * Enforce SFI spec mandate that SYST reside within a page. + */ + if (!ON_SAME_PAGE(syst_pa, syst_pa + syst_hdr->len)) { + pr_info("SYST 0x%llx + 0x%x crosses page\n", + syst_pa, syst_hdr->len); + continue; + } + + /* Success */ + syst_pa = SFI_SYST_SEARCH_BEGIN + offset; + sfi_unmap_memory(start, len); + return 0; + } + + sfi_unmap_memory(start, len); + return -1; +} + +void __init sfi_init(void) +{ + if (!acpi_disabled) + disable_sfi(); + + if (sfi_disabled) + return; + + pr_info("Simple Firmware Interface v0.7 http://simplefirmware.org\n"); + + if (sfi_find_syst() || sfi_parse_syst() || sfi_platform_init()) + disable_sfi(); + + return; +} + +void __init sfi_init_late(void) +{ + int length; + + if (sfi_disabled) + return; + + length = syst_va->header.len; + sfi_unmap_memory(syst_va, sizeof(struct sfi_table_simple)); + + /* Use ioremap now after it is ready */ + sfi_use_ioremap = 1; + syst_va = sfi_map_memory(syst_pa, length); + + sfi_acpi_init(); +} |