diff options
Diffstat (limited to 'drivers/firmware/iscsi_ibft_find.c')
| -rw-r--r-- | drivers/firmware/iscsi_ibft_find.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/drivers/firmware/iscsi_ibft_find.c b/drivers/firmware/iscsi_ibft_find.c new file mode 100644 index 000000000..2224f1dc0 --- /dev/null +++ b/drivers/firmware/iscsi_ibft_find.c @@ -0,0 +1,112 @@ +/* + * Copyright 2007-2010 Red Hat, Inc. + * by Peter Jones <pjones@redhat.com> + * Copyright 2007 IBM, Inc. + * by Konrad Rzeszutek <konradr@linux.vnet.ibm.com> + * Copyright 2008 + * by Konrad Rzeszutek <ketuzsezr@darnok.org> + * + * This code finds the iSCSI Boot Format Table. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License v2.0 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. + */ + +#include <linux/bootmem.h> +#include <linux/blkdev.h> +#include <linux/ctype.h> +#include <linux/device.h> +#include <linux/efi.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/limits.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/stat.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/acpi.h> +#include <linux/iscsi_ibft.h> + +#include <asm/mmzone.h> + +/* + * Physical location of iSCSI Boot Format Table. + */ +struct acpi_table_ibft *ibft_addr; +EXPORT_SYMBOL_GPL(ibft_addr); + +static const struct { + char *sign; +} ibft_signs[] = { + { "iBFT" }, + { "BIFT" }, /* Broadcom iSCSI Offload */ +}; + +#define IBFT_SIGN_LEN 4 +#define IBFT_START 0x80000 /* 512kB */ +#define IBFT_END 0x100000 /* 1MB */ +#define VGA_MEM 0xA0000 /* VGA buffer */ +#define VGA_SIZE 0x20000 /* 128kB */ + +static int __init find_ibft_in_mem(void) +{ + unsigned long pos; + unsigned int len = 0; + void *virt; + int i; + + for (pos = IBFT_START; pos < IBFT_END; pos += 16) { + /* The table can't be inside the VGA BIOS reserved space, + * so skip that area */ + if (pos == VGA_MEM) + pos += VGA_SIZE; + virt = isa_bus_to_virt(pos); + + for (i = 0; i < ARRAY_SIZE(ibft_signs); i++) { + if (memcmp(virt, ibft_signs[i].sign, IBFT_SIGN_LEN) == + 0) { + unsigned long *addr = + (unsigned long *)isa_bus_to_virt(pos + 4); + len = *addr; + /* if the length of the table extends past 1M, + * the table cannot be valid. */ + if (pos + len <= (IBFT_END-1)) { + ibft_addr = (struct acpi_table_ibft *)virt; + pr_info("iBFT found at 0x%lx.\n", pos); + goto done; + } + } + } + } +done: + return len; +} +/* + * Routine used to find the iSCSI Boot Format Table. The logical + * kernel address is set in the ibft_addr global variable. + */ +unsigned long __init find_ibft_region(unsigned long *sizep) +{ + ibft_addr = NULL; + + /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will + * only use ACPI for this */ + + if (!efi_enabled(EFI_BOOT)) + find_ibft_in_mem(); + + if (ibft_addr) { + *sizep = PAGE_ALIGN(ibft_addr->header.length); + return (u64)isa_virt_to_bus(ibft_addr); + } + + *sizep = 0; + return 0; +} |