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linux/drivers/firmware/iscsi_ibft_find.c
Yinghai Lu 935a9fee51 ibft: Fix finding IBFT ACPI table on UEFI
Found one system with UEFI/iBFT, kernel does not detect the iBFT during
iscsi_ibft module loading.

Root cause: on x86 (UEFI), we are calling of find_ibft_region() much earlier
- specifically in setup_arch() before ACPI is enabled.

Try to split acpi checking code out and call that later

At that time ACPI iBFT already get permanent mapped with ioremap.
So isa_virt_to_bus() will get wrong phys from right virt address.
We could just skip that phys address printing.

For legacy one, print the found address early.

-v2: update comments and description according to Konrad.
-v3: fix problem about module use case that is found by Konrad.
-v4: use acpi_get_table() instead of acpi_table_parse() to handle module use case that is found by Konrad again..
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
2011-12-13 09:08:31 -05:00

113 lines
2.8 KiB
C

/*
* 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)
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;
}