105 lines
2.4 KiB
C
105 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright 2007-2010 Red Hat, Inc.
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* by Peter Jones <pjones@redhat.com>
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* Copyright 2007 IBM, Inc.
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* by Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
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* Copyright 2008
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* by Konrad Rzeszutek <ketuzsezr@darnok.org>
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*
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* This code finds the iSCSI Boot Format Table.
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*/
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#include <linux/memblock.h>
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#include <linux/blkdev.h>
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#include <linux/ctype.h>
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#include <linux/device.h>
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#include <linux/efi.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/limits.h>
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/stat.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/acpi.h>
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#include <linux/iscsi_ibft.h>
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#include <asm/mmzone.h>
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/*
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* Physical location of iSCSI Boot Format Table.
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*/
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struct acpi_table_ibft *ibft_addr;
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EXPORT_SYMBOL_GPL(ibft_addr);
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static const struct {
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char *sign;
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} ibft_signs[] = {
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{ "iBFT" },
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{ "BIFT" }, /* Broadcom iSCSI Offload */
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};
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#define IBFT_SIGN_LEN 4
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#define IBFT_START 0x80000 /* 512kB */
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#define IBFT_END 0x100000 /* 1MB */
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#define VGA_MEM 0xA0000 /* VGA buffer */
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#define VGA_SIZE 0x20000 /* 128kB */
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static int __init find_ibft_in_mem(void)
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{
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unsigned long pos;
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unsigned int len = 0;
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void *virt;
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int i;
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for (pos = IBFT_START; pos < IBFT_END; pos += 16) {
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/* The table can't be inside the VGA BIOS reserved space,
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* so skip that area */
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if (pos == VGA_MEM)
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pos += VGA_SIZE;
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virt = isa_bus_to_virt(pos);
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for (i = 0; i < ARRAY_SIZE(ibft_signs); i++) {
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if (memcmp(virt, ibft_signs[i].sign, IBFT_SIGN_LEN) ==
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0) {
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unsigned long *addr =
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(unsigned long *)isa_bus_to_virt(pos + 4);
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len = *addr;
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/* if the length of the table extends past 1M,
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* the table cannot be valid. */
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if (pos + len <= (IBFT_END-1)) {
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ibft_addr = (struct acpi_table_ibft *)virt;
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pr_info("iBFT found at 0x%lx.\n", pos);
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goto done;
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}
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}
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}
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}
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done:
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return len;
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}
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/*
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* Routine used to find the iSCSI Boot Format Table. The logical
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* kernel address is set in the ibft_addr global variable.
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*/
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unsigned long __init find_ibft_region(unsigned long *sizep)
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{
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ibft_addr = NULL;
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/* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
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* only use ACPI for this */
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if (!efi_enabled(EFI_BOOT))
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find_ibft_in_mem();
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if (ibft_addr) {
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*sizep = PAGE_ALIGN(ibft_addr->header.length);
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return (u64)virt_to_phys(ibft_addr);
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}
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*sizep = 0;
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return 0;
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}
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