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linux-next/drivers/firmware/pcdp.c
Greg Pearson 6c4088ac3a pcdp: use early_ioremap/early_iounmap to access pcdp table
efi_setup_pcdp_console() is called during boot to parse the HCDP/PCDP
EFI system table and setup an early console for printk output.  The
routine uses ioremap/iounmap to setup access to the HCDP/PCDP table
information.

The call to ioremap is happening early in the boot process which leads
to a panic on x86_64 systems:

    panic+0x01ca
    do_exit+0x043c
    oops_end+0x00a7
    no_context+0x0119
    __bad_area_nosemaphore+0x0138
    bad_area_nosemaphore+0x000e
    do_page_fault+0x0321
    page_fault+0x0020
    reserve_memtype+0x02a1
    __ioremap_caller+0x0123
    ioremap_nocache+0x0012
    efi_setup_pcdp_console+0x002b
    setup_arch+0x03a9
    start_kernel+0x00d4
    x86_64_start_reservations+0x012c
    x86_64_start_kernel+0x00fe

This replaces the calls to ioremap/iounmap in efi_setup_pcdp_console()
with calls to early_ioremap/early_iounmap which can be called during
early boot.

This patch was tested on an x86_64 prototype system which uses the
HCDP/PCDP table for early console setup.

Signed-off-by: Greg Pearson <greg.pearson@hp.com>
Acked-by: Khalid Aziz <khalid.aziz@hp.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:11 -07:00

137 lines
3.3 KiB
C

/*
* Parse the EFI PCDP table to locate the console device.
*
* (c) Copyright 2002, 2003, 2004 Hewlett-Packard Development Company, L.P.
* Khalid Aziz <khalid.aziz@hp.com>
* Alex Williamson <alex.williamson@hp.com>
* Bjorn Helgaas <bjorn.helgaas@hp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/acpi.h>
#include <linux/console.h>
#include <linux/efi.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <asm/vga.h>
#include "pcdp.h"
static int __init
setup_serial_console(struct pcdp_uart *uart)
{
#ifdef CONFIG_SERIAL_8250_CONSOLE
int mmio;
static char options[64], *p = options;
char parity;
mmio = (uart->addr.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
p += sprintf(p, "uart8250,%s,0x%llx",
mmio ? "mmio" : "io", uart->addr.address);
if (uart->baud) {
p += sprintf(p, ",%llu", uart->baud);
if (uart->bits) {
switch (uart->parity) {
case 0x2: parity = 'e'; break;
case 0x3: parity = 'o'; break;
default: parity = 'n';
}
p += sprintf(p, "%c%d", parity, uart->bits);
}
}
add_preferred_console("uart", 8250, &options[9]);
return setup_early_serial8250_console(options);
#else
return -ENODEV;
#endif
}
static int __init
setup_vga_console(struct pcdp_device *dev)
{
#if defined(CONFIG_VT) && defined(CONFIG_VGA_CONSOLE)
u8 *if_ptr;
if_ptr = ((u8 *)dev + sizeof(struct pcdp_device));
if (if_ptr[0] == PCDP_IF_PCI) {
struct pcdp_if_pci if_pci;
/* struct copy since ifptr might not be correctly aligned */
memcpy(&if_pci, if_ptr, sizeof(if_pci));
if (if_pci.trans & PCDP_PCI_TRANS_IOPORT)
vga_console_iobase = if_pci.ioport_tra;
if (if_pci.trans & PCDP_PCI_TRANS_MMIO)
vga_console_membase = if_pci.mmio_tra;
}
if (efi_mem_type(vga_console_membase + 0xA0000) == EFI_CONVENTIONAL_MEMORY) {
printk(KERN_ERR "PCDP: VGA selected, but frame buffer is not MMIO!\n");
return -ENODEV;
}
conswitchp = &vga_con;
printk(KERN_INFO "PCDP: VGA console\n");
return 0;
#else
return -ENODEV;
#endif
}
int __init
efi_setup_pcdp_console(char *cmdline)
{
struct pcdp *pcdp;
struct pcdp_uart *uart;
struct pcdp_device *dev, *end;
int i, serial = 0;
int rc = -ENODEV;
if (efi.hcdp == EFI_INVALID_TABLE_ADDR)
return -ENODEV;
pcdp = early_ioremap(efi.hcdp, 4096);
printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, efi.hcdp);
if (strstr(cmdline, "console=hcdp")) {
if (pcdp->rev < 3)
serial = 1;
} else if (strstr(cmdline, "console=")) {
printk(KERN_INFO "Explicit \"console=\"; ignoring PCDP\n");
goto out;
}
if (pcdp->rev < 3 && efi_uart_console_only())
serial = 1;
for (i = 0, uart = pcdp->uart; i < pcdp->num_uarts; i++, uart++) {
if (uart->flags & PCDP_UART_PRIMARY_CONSOLE || serial) {
if (uart->type == PCDP_CONSOLE_UART) {
rc = setup_serial_console(uart);
goto out;
}
}
}
end = (struct pcdp_device *) ((u8 *) pcdp + pcdp->length);
for (dev = (struct pcdp_device *) (pcdp->uart + pcdp->num_uarts);
dev < end;
dev = (struct pcdp_device *) ((u8 *) dev + dev->length)) {
if (dev->flags & PCDP_PRIMARY_CONSOLE) {
if (dev->type == PCDP_CONSOLE_VGA) {
rc = setup_vga_console(dev);
goto out;
}
}
}
out:
early_iounmap(pcdp, 4096);
return rc;
}