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Commit 18a44a7f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull more x86 fixes from Peter Anvin:
 "Additional x86 fixes.  Three of these patches are pure documentation,
  two are pretty trivial; the remaining one fixes boot problems on some
  non-BIOS machines."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Make sure we can boot in the case the BDA contains pure garbage
  x86, efi: Mark disable_runtime as __initdata
  x86, doc: Fix incorrect comment about 64-bit code segment descriptors
  doc, kernel-parameters: Document 'console=hvc<n>'
  doc, xen: Mention 'earlyprintk=xen' in the documentation.
  ACPI: Overriding ACPI tables via initrd only works with an initrd and on X86
parents 309667e5 7c100936

Documentation/kernel-parameters.txt

+5 −0
Original line number Diff line number Diff line
@@ -564,6 +564,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			UART at the specified I/O port or MMIO address,

			switching to the matching ttyS device later.  The

			options are the same as for ttyS, above.

		hvc<n>	Use the hypervisor console device <n>. This is for

			both Xen and PowerPC hypervisors.



                If the device connected to the port is not a TTY but a braille

                device, prepend "brl," before the device type, for instance
@@ -757,6 +759,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 


	earlyprintk=	[X86,SH,BLACKFIN]

			earlyprintk=vga

			earlyprintk=xen

			earlyprintk=serial[,ttySn[,baudrate]]

			earlyprintk=ttySn[,baudrate]

			earlyprintk=dbgp[debugController#]
@@ -774,6 +777,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			The VGA output is eventually overwritten by the real

			console.



			The xen output can only be used by Xen PV guests.



	ekgdboc=	[X86,KGDB] Allow early kernel console debugging

			ekgdboc=kbd

arch/x86/kernel/head.c

+34 −19
Original line number Diff line number Diff line
@@ -5,8 +5,6 @@ 
#include <asm/setup.h>

#include <asm/bios_ebda.h>



#define BIOS_LOWMEM_KILOBYTES 0x413



/*

 * The BIOS places the EBDA/XBDA at the top of conventional

 * memory, and usually decreases the reported amount of
@@ -16,17 +14,30 @@ 
 * chipset: reserve a page before VGA to prevent PCI prefetch

 * into it (errata #56). Usually the page is reserved anyways,

 * unless you have no PS/2 mouse plugged in.

 *

 * This functions is deliberately very conservative.  Losing

 * memory in the bottom megabyte is rarely a problem, as long

 * as we have enough memory to install the trampoline.  Using

 * memory that is in use by the BIOS or by some DMA device

 * the BIOS didn't shut down *is* a big problem.

 */



#define BIOS_LOWMEM_KILOBYTES	0x413

#define LOWMEM_CAP		0x9f000U	/* Absolute maximum */

#define INSANE_CUTOFF		0x20000U	/* Less than this = insane */



void __init reserve_ebda_region(void)

{

	unsigned int lowmem, ebda_addr;



	/* To determine the position of the EBDA and the */

	/* end of conventional memory, we need to look at */

	/* the BIOS data area. In a paravirtual environment */

	/* that area is absent. We'll just have to assume */

	/* that the paravirt case can handle memory setup */

	/* correctly, without our help. */

	/*

	 * To determine the position of the EBDA and the

	 * end of conventional memory, we need to look at

	 * the BIOS data area. In a paravirtual environment

	 * that area is absent. We'll just have to assume

	 * that the paravirt case can handle memory setup

	 * correctly, without our help.

	 */

	if (paravirt_enabled())

		return;
@@ -37,19 +48,23 @@ void __init reserve_ebda_region(void) 
	/* start of EBDA area */

	ebda_addr = get_bios_ebda();



	/* Fixup: bios puts an EBDA in the top 64K segment */

	/* of conventional memory, but does not adjust lowmem. */

	if ((lowmem - ebda_addr) <= 0x10000)

		lowmem = ebda_addr;

	/*

	 * Note: some old Dells seem to need 4k EBDA without

	 * reporting so, so just consider the memory above 0x9f000

	 * to be off limits (bugzilla 2990).

	 */



	/* If the EBDA address is below 128K, assume it is bogus */

	if (ebda_addr < INSANE_CUTOFF)

		ebda_addr = LOWMEM_CAP;



	/* Fixup: bios does not report an EBDA at all. */

	/* Some old Dells seem to need 4k anyhow (bugzilla 2990) */

	if ((ebda_addr == 0) && (lowmem >= 0x9f000))

		lowmem = 0x9f000;

	/* If lowmem is less than 128K, assume it is bogus */

	if (lowmem < INSANE_CUTOFF)

		lowmem = LOWMEM_CAP;



	/* Paranoia: should never happen, but... */

	if ((lowmem == 0) || (lowmem >= 0x100000))

		lowmem = 0x9f000;

	/* Use the lower of the lowmem and EBDA markers as the cutoff */

	lowmem = min(lowmem, ebda_addr);

	lowmem = min(lowmem, LOWMEM_CAP); /* Absolute cap */



	/* reserve all memory between lowmem and the 1MB mark */

	memblock_reserve(lowmem, 0x100000 - lowmem);

arch/x86/kernel/head_64.S

+2 −2
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ L3_START_KERNEL = pud_index(__START_KERNEL_map) 
	.globl startup_64

startup_64:

	/*

	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 1,

	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,

	 * and someone has loaded an identity mapped page table

	 * for us.  These identity mapped page tables map all of the

	 * kernel pages and possibly all of memory.
@@ -159,7 +159,7 @@ startup_64: 
	jmp 1f

ENTRY(secondary_startup_64)

	/*

	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 1,

	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,

	 * and someone has loaded a mapped page table.

	 *

	 * %rsi holds a physical pointer to real_mode_data.

arch/x86/platform/efi/efi.c

+1 −1
Original line number Diff line number Diff line
@@ -85,7 +85,7 @@ int efi_enabled(int facility) 
}

EXPORT_SYMBOL(efi_enabled);



static bool disable_runtime = false;

static bool __initdata disable_runtime = false;

static int __init setup_noefi(char *arg)

{

	disable_runtime = true;

drivers/acpi/Kconfig

+2 −1
Original line number Diff line number Diff line
@@ -266,7 +266,8 @@ config ACPI_CUSTOM_DSDT 
	default ACPI_CUSTOM_DSDT_FILE != ""



config ACPI_INITRD_TABLE_OVERRIDE

	bool "ACPI tables can be passed via uncompressed cpio in initrd"

	bool "ACPI tables override via initrd"

	depends on BLK_DEV_INITRD && X86

	default n

	help

	  This option provides functionality to override arbitrary ACPI tables