x86: move x86-specific documentation into Documentation/x86

The current organization of the x86 documentation makes it appear as
if the "i386" documentation doesn't apply to x86-64, which is does.
Thus, move that documentation into Documentation/x86, and move the
x86-64-specific stuff into Documentation/x86/x86_64 with the eventual
goal to move stuff that isn't actually 64-bit specific back into
Documentation/x86.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

12 files changed, 1754 insertions, 0 deletions

diff --git a/Documentation/x86/i386/IO-APIC.txt b/Documentation/x86/i386/IO-APIC.txt
new file mode 100644
index 000000000000..30b4c714fbe1
--- /dev/null
+++ b/Documentation/x86/i386/IO-APIC.txt
@@ -0,0 +1,119 @@
+Most (all) Intel-MP compliant SMP boards have the so-called 'IO-APIC',
+which is an enhanced interrupt controller. It enables us to route
+hardware interrupts to multiple CPUs, or to CPU groups. Without an
+IO-APIC, interrupts from hardware will be delivered only to the
+CPU which boots the operating system (usually CPU#0).
+
+Linux supports all variants of compliant SMP boards, including ones with
+multiple IO-APICs. Multiple IO-APICs are used in high-end servers to
+distribute IRQ load further.
+
+There are (a few) known breakages in certain older boards, such bugs are
+usually worked around by the kernel. If your MP-compliant SMP board does
+not boot Linux, then consult the linux-smp mailing list archives first.
+
+If your box boots fine with enabled IO-APIC IRQs, then your
+/proc/interrupts will look like this one:
+
+   ---------------------------->
+  hell:~> cat /proc/interrupts
+             CPU0
+    0:    1360293    IO-APIC-edge  timer
+    1:          4    IO-APIC-edge  keyboard
+    2:          0          XT-PIC  cascade
+   13:          1          XT-PIC  fpu
+   14:       1448    IO-APIC-edge  ide0
+   16:      28232   IO-APIC-level  Intel EtherExpress Pro 10/100 Ethernet
+   17:      51304   IO-APIC-level  eth0
+  NMI:          0
+  ERR:          0
+  hell:~>
+  <----------------------------
+
+Some interrupts are still listed as 'XT PIC', but this is not a problem;
+none of those IRQ sources is performance-critical.
+
+
+In the unlikely case that your board does not create a working mp-table,
+you can use the pirq= boot parameter to 'hand-construct' IRQ entries. This
+is non-trivial though and cannot be automated. One sample /etc/lilo.conf
+entry:
+
+        append="pirq=15,11,10"
+
+The actual numbers depend on your system, on your PCI cards and on their
+PCI slot position. Usually PCI slots are 'daisy chained' before they are
+connected to the PCI chipset IRQ routing facility (the incoming PIRQ1-4
+lines):
+
+               ,-.        ,-.        ,-.        ,-.        ,-.
+     PIRQ4 ----| |-.    ,-| |-.    ,-| |-.    ,-| |--------| |
+               |S|  \  /  |S|  \  /  |S|  \  /  |S|        |S|
+     PIRQ3 ----|l|-. `/---|l|-. `/---|l|-. `/---|l|--------|l|
+               |o|  \/    |o|  \/    |o|  \/    |o|        |o|
+     PIRQ2 ----|t|-./`----|t|-./`----|t|-./`----|t|--------|t|
+               |1| /\     |2| /\     |3| /\     |4|        |5|
+     PIRQ1 ----| |-  `----| |-  `----| |-  `----| |--------| |
+               `-'        `-'        `-'        `-'        `-'
+
+Every PCI card emits a PCI IRQ, which can be INTA, INTB, INTC or INTD:
+
+                               ,-.
+                         INTD--| |
+                               |S|
+                         INTC--|l|
+                               |o|
+                         INTB--|t|
+                               |x|
+                         INTA--| |
+                               `-'
+
+These INTA-D PCI IRQs are always 'local to the card', their real meaning
+depends on which slot they are in. If you look at the daisy chaining diagram,
+a card in slot4, issuing INTA IRQ, it will end up as a signal on PIRQ4 of
+the PCI chipset. Most cards issue INTA, this creates optimal distribution
+between the PIRQ lines. (distributing IRQ sources properly is not a
+necessity, PCI IRQs can be shared at will, but it's a good for performance
+to have non shared interrupts). Slot5 should be used for videocards, they
+do not use interrupts normally, thus they are not daisy chained either.
+
+so if you have your SCSI card (IRQ11) in Slot1, Tulip card (IRQ9) in
+Slot2, then you'll have to specify this pirq= line:
+
+        append="pirq=11,9"
+
+the following script tries to figure out such a default pirq= line from
+your PCI configuration:
+
+        echo -n pirq=; echo `scanpci | grep T_L | cut -c56-` | sed 's/ /,/g'
+
+note that this script wont work if you have skipped a few slots or if your
+board does not do default daisy-chaining. (or the IO-APIC has the PIRQ pins
+connected in some strange way). E.g. if in the above case you have your SCSI
+card (IRQ11) in Slot3, and have Slot1 empty:
+
+        append="pirq=0,9,11"
+
+[value '0' is a generic 'placeholder', reserved for empty (or non-IRQ emitting)
+slots.]
+
+Generally, it's always possible to find out the correct pirq= settings, just
+permute all IRQ numbers properly ... it will take some time though. An
+'incorrect' pirq line will cause the booting process to hang, or a device
+won't function properly (e.g. if it's inserted as a module).
+
+If you have 2 PCI buses, then you can use up to 8 pirq values, although such
+boards tend to have a good configuration.
+
+Be prepared that it might happen that you need some strange pirq line:
+
+        append="pirq=0,0,0,0,0,0,9,11"
+
+Use smart trial-and-error techniques to find out the correct pirq line ...
+
+Good luck and mail to linux-smp@vger.kernel.org or
+linux-kernel@vger.kernel.org if you have any problems that are not covered
+by this document.
+
+-- mingo
+
diff --git a/Documentation/x86/i386/boot.txt b/Documentation/x86/i386/boot.txt
new file mode 100644
index 000000000000..147bfe511cdd
--- /dev/null
+++ b/Documentation/x86/i386/boot.txt
@@ -0,0 +1,900 @@
+                     THE LINUX/x86 BOOT PROTOCOL
+                     ---------------------------
+
+On the x86 platform, the Linux kernel uses a rather complicated boot
+convention.  This has evolved partially due to historical aspects, as
+well as the desire in the early days to have the kernel itself be a
+bootable image, the complicated PC memory model and due to changed
+expectations in the PC industry caused by the effective demise of
+real-mode DOS as a mainstream operating system.
+
+Currently, the following versions of the Linux/x86 boot protocol exist.
+
+Old kernels:    zImage/Image support only.  Some very early kernels
+                may not even support a command line.
+
+Protocol 2.00:  (Kernel 1.3.73) Added bzImage and initrd support, as
+                well as a formalized way to communicate between the
+                boot loader and the kernel.  setup.S made relocatable,
+                although the traditional setup area still assumed
+                writable.
+
+Protocol 2.01:  (Kernel 1.3.76) Added a heap overrun warning.
+
+Protocol 2.02:  (Kernel 2.4.0-test3-pre3) New command line protocol.
+                Lower the conventional memory ceiling.  No overwrite
+                of the traditional setup area, thus making booting
+                safe for systems which use the EBDA from SMM or 32-bit
+                BIOS entry points.  zImage deprecated but still
+                supported.
+
+Protocol 2.03:  (Kernel 2.4.18-pre1) Explicitly makes the highest possible
+                initrd address available to the bootloader.
+
+Protocol 2.04:  (Kernel 2.6.14) Extend the syssize field to four bytes.
+
+Protocol 2.05:  (Kernel 2.6.20) Make protected mode kernel relocatable.
+                Introduce relocatable_kernel and kernel_alignment fields.
+
+Protocol 2.06:  (Kernel 2.6.22) Added a field that contains the size of
+                the boot command line.
+
+Protocol 2.07:  (Kernel 2.6.24) Added paravirtualised boot protocol.
+                Introduced hardware_subarch and hardware_subarch_data
+                and KEEP_SEGMENTS flag in load_flags.
+
+Protocol 2.08:  (Kernel 2.6.26) Added crc32 checksum and ELF format
+                payload. Introduced payload_offset and payload length
+                fields to aid in locating the payload.
+
+Protocol 2.09:  (Kernel 2.6.26) Added a field of 64-bit physical
+                pointer to single linked list of struct setup_data.
+
+**** MEMORY LAYOUT
+
+The traditional memory map for the kernel loader, used for Image or
+zImage kernels, typically looks like:
+
+        |                        |
+0A0000  +------------------------+
+        |  Reserved for BIOS     |      Do not use.  Reserved for BIOS EBDA.
+09A000  +------------------------+
+        |  Command line          |
+        |  Stack/heap            |      For use by the kernel real-mode code.
+098000  +------------------------+      
+        |  Kernel setup          |      The kernel real-mode code.
+090200  +------------------------+
+        |  Kernel boot sector    |      The kernel legacy boot sector.
+090000  +------------------------+
+        |  Protected-mode kernel |      The bulk of the kernel image.
+010000  +------------------------+
+        |  Boot loader           |      <- Boot sector entry point 0000:7C00
+001000  +------------------------+
+        |  Reserved for MBR/BIOS |
+000800  +------------------------+
+        |  Typically used by MBR |
+000600  +------------------------+ 
+        |  BIOS use only         |
+000000  +------------------------+
+
+
+When using bzImage, the protected-mode kernel was relocated to
+0x100000 ("high memory"), and the kernel real-mode block (boot sector,
+setup, and stack/heap) was made relocatable to any address between
+0x10000 and end of low memory. Unfortunately, in protocols 2.00 and
+2.01 the 0x90000+ memory range is still used internally by the kernel;
+the 2.02 protocol resolves that problem.
+
+It is desirable to keep the "memory ceiling" -- the highest point in
+low memory touched by the boot loader -- as low as possible, since
+some newer BIOSes have begun to allocate some rather large amounts of
+memory, called the Extended BIOS Data Area, near the top of low
+memory.  The boot loader should use the "INT 12h" BIOS call to verify
+how much low memory is available.
+
+Unfortunately, if INT 12h reports that the amount of memory is too
+low, there is usually nothing the boot loader can do but to report an
+error to the user.  The boot loader should therefore be designed to
+take up as little space in low memory as it reasonably can.  For
+zImage or old bzImage kernels, which need data written into the
+0x90000 segment, the boot loader should make sure not to use memory
+above the 0x9A000 point; too many BIOSes will break above that point.
+
+For a modern bzImage kernel with boot protocol version >= 2.02, a
+memory layout like the following is suggested:
+
+        ~                        ~
+        |  Protected-mode kernel |
+100000  +------------------------+
+        |  I/O memory hole       |
+0A0000  +------------------------+
+        |  Reserved for BIOS     |      Leave as much as possible unused
+        ~                        ~
+        |  Command line          |      (Can also be below the X+10000 mark)
+X+10000 +------------------------+
+        |  Stack/heap            |      For use by the kernel real-mode code.
+X+08000 +------------------------+      
+        |  Kernel setup          |      The kernel real-mode code.
+        |  Kernel boot sector    |      The kernel legacy boot sector.
+X       +------------------------+
+        |  Boot loader           |      <- Boot sector entry point 0000:7C00
+001000  +------------------------+
+        |  Reserved for MBR/BIOS |
+000800  +------------------------+
+        |  Typically used by MBR |
+000600  +------------------------+ 
+        |  BIOS use only         |
+000000  +------------------------+
+
+... where the address X is as low as the design of the boot loader
+permits.
+
+
+**** THE REAL-MODE KERNEL HEADER
+
+In the following text, and anywhere in the kernel boot sequence, "a
+sector" refers to 512 bytes.  It is independent of the actual sector
+size of the underlying medium.
+
+The first step in loading a Linux kernel should be to load the
+real-mode code (boot sector and setup code) and then examine the
+following header at offset 0x01f1.  The real-mode code can total up to
+32K, although the boot loader may choose to load only the first two
+sectors (1K) and then examine the bootup sector size.
+
+The header looks like:
+
+Offset  Proto   Name            Meaning
+/Size
+
+01F1/1  ALL(1   setup_sects     The size of the setup in sectors
+01F2/2  ALL     root_flags      If set, the root is mounted readonly
+01F4/4  2.04+(2 syssize         The size of the 32-bit code in 16-byte paras
+01F8/2  ALL     ram_size        DO NOT USE - for bootsect.S use only
+01FA/2  ALL     vid_mode        Video mode control
+01FC/2  ALL     root_dev        Default root device number
+01FE/2  ALL     boot_flag       0xAA55 magic number
+0200/2  2.00+   jump            Jump instruction
+0202/4  2.00+   header          Magic signature "HdrS"
+0206/2  2.00+   version         Boot protocol version supported
+0208/4  2.00+   realmode_swtch  Boot loader hook (see below)
+020C/2  2.00+   start_sys       The load-low segment (0x1000) (obsolete)
+020E/2  2.00+   kernel_version  Pointer to kernel version string
+0210/1  2.00+   type_of_loader  Boot loader identifier
+0211/1  2.00+   loadflags       Boot protocol option flags
+0212/2  2.00+   setup_move_size Move to high memory size (used with hooks)
+0214/4  2.00+   code32_start    Boot loader hook (see below)
+0218/4  2.00+   ramdisk_image   initrd load address (set by boot loader)
+021C/4  2.00+   ramdisk_size    initrd size (set by boot loader)
+0220/4  2.00+   bootsect_kludge DO NOT USE - for bootsect.S use only
+0224/2  2.01+   heap_end_ptr    Free memory after setup end
+0226/2  N/A     pad1            Unused
+0228/4  2.02+   cmd_line_ptr    32-bit pointer to the kernel command line
+022C/4  2.03+   initrd_addr_max Highest legal initrd address
+0230/4  2.05+   kernel_alignment Physical addr alignment required for kernel
+0234/1  2.05+   relocatable_kernel Whether kernel is relocatable or not
+0235/3  N/A     pad2            Unused
+0238/4  2.06+   cmdline_size    Maximum size of the kernel command line
+023C/4  2.07+   hardware_subarch Hardware subarchitecture
+0240/8  2.07+   hardware_subarch_data Subarchitecture-specific data
+0248/4  2.08+   payload_offset  Offset of kernel payload
+024C/4  2.08+   payload_length  Length of kernel payload
+0250/8  2.09+   setup_data      64-bit physical pointer to linked list
+                                of struct setup_data
+
+(1) For backwards compatibility, if the setup_sects field contains 0, the
+    real value is 4.
+
+(2) For boot protocol prior to 2.04, the upper two bytes of the syssize
+    field are unusable, which means the size of a bzImage kernel
+    cannot be determined.
+
+If the "HdrS" (0x53726448) magic number is not found at offset 0x202,
+the boot protocol version is "old".  Loading an old kernel, the
+following parameters should be assumed:
+
+        Image type = zImage
+        initrd not supported
+        Real-mode kernel must be located at 0x90000.
+
+Otherwise, the "version" field contains the protocol version,
+e.g. protocol version 2.01 will contain 0x0201 in this field.  When
+setting fields in the header, you must make sure only to set fields
+supported by the protocol version in use.
+
+
+**** DETAILS OF HEADER FIELDS
+
+For each field, some are information from the kernel to the bootloader
+("read"), some are expected to be filled out by the bootloader
+("write"), and some are expected to be read and modified by the
+bootloader ("modify").
+
+All general purpose boot loaders should write the fields marked
+(obligatory).  Boot loaders who want to load the kernel at a
+nonstandard address should fill in the fields marked (reloc); other
+boot loaders can ignore those fields.
+
+The byte order of all fields is littleendian (this is x86, after all.)
+
+Field name:     setup_sects
+Type:           read
+Offset/size:    0x1f1/1
+Protocol:       ALL
+
+  The size of the setup code in 512-byte sectors.  If this field is
+  0, the real value is 4.  The real-mode code consists of the boot
+  sector (always one 512-byte sector) plus the setup code.
+
+Field name:      root_flags
+Type:            modify (optional)
+Offset/size:     0x1f2/2
+Protocol:        ALL
+
+  If this field is nonzero, the root defaults to readonly.  The use of
+  this field is deprecated; use the "ro" or "rw" options on the
+  command line instead.
+
+Field name:     syssize
+Type:           read
+Offset/size:    0x1f4/4 (protocol 2.04+) 0x1f4/2 (protocol ALL)
+Protocol:       2.04+
+
+  The size of the protected-mode code in units of 16-byte paragraphs.
+  For protocol versions older than 2.04 this field is only two bytes
+  wide, and therefore cannot be trusted for the size of a kernel if
+  the LOAD_HIGH flag is set.
+
+Field name:     ram_size
+Type:           kernel internal
+Offset/size:    0x1f8/2
+Protocol:       ALL
+
+  This field is obsolete.
+
+Field name:     vid_mode
+Type:           modify (obligatory)
+Offset/size:    0x1fa/2
+
+  Please see the section on SPECIAL COMMAND LINE OPTIONS.
+
+Field name:     root_dev
+Type:           modify (optional)
+Offset/size:    0x1fc/2
+Protocol:       ALL
+
+  The default root device device number.  The use of this field is
+  deprecated, use the "root=" option on the command line instead.
+
+Field name:     boot_flag
+Type:           read
+Offset/size:    0x1fe/2
+Protocol:       ALL
+
+  Contains 0xAA55.  This is the closest thing old Linux kernels have
+  to a magic number.
+
+Field name:     jump
+Type:           read
+Offset/size:    0x200/2
+Protocol:       2.00+
+
+  Contains an x86 jump instruction, 0xEB followed by a signed offset
+  relative to byte 0x202.  This can be used to determine the size of
+  the header.
+
+Field name:     header
+Type:           read
+Offset/size:    0x202/4
+Protocol:       2.00+
+
+  Contains the magic number "HdrS" (0x53726448).
+
+Field name:     version
+Type:           read
+Offset/size:    0x206/2
+Protocol:       2.00+
+
+  Contains the boot protocol version, in (major << 8)+minor format,
+  e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version
+  10.17.
+
+Field name:     readmode_swtch
+Type:           modify (optional)
+Offset/size:    0x208/4
+Protocol:       2.00+
+
+  Boot loader hook (see ADVANCED BOOT LOADER HOOKS below.)
+
+Field name:     start_sys
+Type:           read
+Offset/size:    0x20c/4
+Protocol:       2.00+
+
+  The load low segment (0x1000).  Obsolete.
+
+Field name:     kernel_version
+Type:           read
+Offset/size:    0x20e/2
+Protocol:       2.00+
+
+  If set to a nonzero value, contains a pointer to a NUL-terminated
+  human-readable kernel version number string, less 0x200.  This can
+  be used to display the kernel version to the user.  This value
+  should be less than (0x200*setup_sects).
+
+  For example, if this value is set to 0x1c00, the kernel version
+  number string can be found at offset 0x1e00 in the kernel file.
+  This is a valid value if and only if the "setup_sects" field
+  contains the value 15 or higher, as:
+
+        0x1c00  < 15*0x200 (= 0x1e00) but
+        0x1c00 >= 14*0x200 (= 0x1c00)
+
+        0x1c00 >> 9 = 14, so the minimum value for setup_secs is 15.
+
+Field name:     type_of_loader
+Type:           write (obligatory)
+Offset/size:    0x210/1
+Protocol:       2.00+
+
+  If your boot loader has an assigned id (see table below), enter
+  0xTV here, where T is an identifier for the boot loader and V is
+  a version number.  Otherwise, enter 0xFF here.
+
+  Assigned boot loader ids:
+        0  LILO                 (0x00 reserved for pre-2.00 bootloader)
+        1  Loadlin
+        2  bootsect-loader      (0x20, all other values reserved)
+        3  SYSLINUX
+        4  EtherBoot
+        5  ELILO
+        7  GRuB
+        8  U-BOOT
+        9  Xen
+        A  Gujin
+        B  Qemu
+
+  Please contact <hpa@zytor.com> if you need a bootloader ID
+  value assigned.
+
+Field name:     loadflags
+Type:           modify (obligatory)
+Offset/size:    0x211/1
+Protocol:       2.00+
+
+  This field is a bitmask.
+
+  Bit 0 (read): LOADED_HIGH
+        - If 0, the protected-mode code is loaded at 0x10000.
+        - If 1, the protected-mode code is loaded at 0x100000.
+
+  Bit 5 (write): QUIET_FLAG
+        - If 0, print early messages.
+        - If 1, suppress early messages.
+                This requests to the kernel (decompressor and early
+                kernel) to not write early messages that require
+                accessing the display hardware directly.
+
+  Bit 6 (write): KEEP_SEGMENTS
+        Protocol: 2.07+
+        - If 0, reload the segment registers in the 32bit entry point.
+        - If 1, do not reload the segment registers in the 32bit entry point.
+                Assume that %cs %ds %ss %es are all set to flat segments with
+                a base of 0 (or the equivalent for their environment).
+
+  Bit 7 (write): CAN_USE_HEAP
+        Set this bit to 1 to indicate that the value entered in the
+        heap_end_ptr is valid.  If this field is clear, some setup code
+        functionality will be disabled.
+
+Field name:     setup_move_size
+Type:           modify (obligatory)
+Offset/size:    0x212/2
+Protocol:       2.00-2.01
+
+  When using protocol 2.00 or 2.01, if the real mode kernel is not
+  loaded at 0x90000, it gets moved there later in the loading
+  sequence.  Fill in this field if you want additional data (such as
+  the kernel command line) moved in addition to the real-mode kernel
+  itself.
+
+  The unit is bytes starting with the beginning of the boot sector.
+  
+  This field is can be ignored when the protocol is 2.02 or higher, or
+  if the real-mode code is loaded at 0x90000.
+
+Field name:     code32_start
+Type:           modify (optional, reloc)
+Offset/size:    0x214/4
+Protocol:       2.00+
+
+  The address to jump to in protected mode.  This defaults to the load
+  address of the kernel, and can be used by the boot loader to
+  determine the proper load address.
+
+  This field can be modified for two purposes:
+
+  1. as a boot loader hook (see ADVANCED BOOT LOADER HOOKS below.)
+
+  2. if a bootloader which does not install a hook loads a
+     relocatable kernel at a nonstandard address it will have to modify
+     this field to point to the load address.
+
+Field name:     ramdisk_image
+Type:           write (obligatory)
+Offset/size:    0x218/4
+Protocol:       2.00+
+
+  The 32-bit linear address of the initial ramdisk or ramfs.  Leave at
+  zero if there is no initial ramdisk/ramfs.
+
+Field name:     ramdisk_size
+Type:           write (obligatory)
+Offset/size:    0x21c/4
+Protocol:       2.00+
+
+  Size of the initial ramdisk or ramfs.  Leave at zero if there is no
+  initial ramdisk/ramfs.
+
+Field name:     bootsect_kludge
+Type:           kernel internal
+Offset/size:    0x220/4
+Protocol:       2.00+
+
+  This field is obsolete.
+
+Field name:     heap_end_ptr
+Type:           write (obligatory)
+Offset/size:    0x224/2
+Protocol:       2.01+
+
+  Set this field to the offset (from the beginning of the real-mode
+  code) of the end of the setup stack/heap, minus 0x0200.
+
+Field name:     cmd_line_ptr
+Type:           write (obligatory)
+Offset/size:    0x228/4
+Protocol:       2.02+
+
+  Set this field to the linear address of the kernel command line.
+  The kernel command line can be located anywhere between the end of
+  the setup heap and 0xA0000; it does not have to be located in the
+  same 64K segment as the real-mode code itself.
+
+  Fill in this field even if your boot loader does not support a
+  command line, in which case you can point this to an empty string
+  (or better yet, to the string "auto".)  If this field is left at
+  zero, the kernel will assume that your boot loader does not support
+  the 2.02+ protocol.
+
+Field name:     initrd_addr_max
+Type:           read
+Offset/size:    0x22c/4
+Protocol:       2.03+
+
+  The maximum address that may be occupied by the initial
+  ramdisk/ramfs contents.  For boot protocols 2.02 or earlier, this
+  field is not present, and the maximum address is 0x37FFFFFF.  (This
+  address is defined as the address of the highest safe byte, so if
+  your ramdisk is exactly 131072 bytes long and this field is
+  0x37FFFFFF, you can start your ramdisk at 0x37FE0000.)
+
+Field name:     kernel_alignment
+Type:           read (reloc)
+Offset/size:    0x230/4
+Protocol:       2.05+
+
+  Alignment unit required by the kernel (if relocatable_kernel is true.)
+
+Field name:     relocatable_kernel
+Type:           read (reloc)
+Offset/size:    0x234/1
+Protocol:       2.05+
+
+  If this field is nonzero, the protected-mode part of the kernel can
+  be loaded at any address that satisfies the kernel_alignment field.
+  After loading, the boot loader must set the code32_start field to
+  point to the loaded code, or to a boot loader hook.
+
+Field name:     cmdline_size
+Type:           read
+Offset/size:    0x238/4
+Protocol:       2.06+
+
+  The maximum size of the command line without the terminating
+  zero. This means that the command line can contain at most
+  cmdline_size characters. With protocol version 2.05 and earlier, the
+  maximum size was 255.
+
+Field name:     hardware_subarch
+Type:           write (optional, defaults to x86/PC)
+Offset/size:    0x23c/4
+Protocol:       2.07+
+
+  In a paravirtualized environment the hardware low level architectural
+  pieces such as interrupt handling, page table handling, and
+  accessing process control registers needs to be done differently.
+
+  This field allows the bootloader to inform the kernel we are in one
+  one of those environments.
+
+  0x00000000    The default x86/PC environment
+  0x00000001    lguest
+  0x00000002    Xen
+
+Field name:     hardware_subarch_data
+Type:           write (subarch-dependent)
+Offset/size:    0x240/8
+Protocol:       2.07+
+
+  A pointer to data that is specific to hardware subarch
+  This field is currently unused for the default x86/PC environment,
+  do not modify.
+
+Field name:     payload_offset
+Type:           read
+Offset/size:    0x248/4
+Protocol:       2.08+
+
+  If non-zero then this field contains the offset from the end of the
+  real-mode code to the payload.
+
+  The payload may be compressed. The format of both the compressed and
+  uncompressed data should be determined using the standard magic
+  numbers. Currently only gzip compressed ELF is used.
+  
+Field name:     payload_length
+Type:           read
+Offset/size:    0x24c/4
+Protocol:       2.08+
+
+  The length of the payload.
+
+Field name:     setup_data
+Type:           write (special)
+Offset/size:    0x250/8
+Protocol:       2.09+
+
+  The 64-bit physical pointer to NULL terminated single linked list of
+  struct setup_data. This is used to define a more extensible boot
+  parameters passing mechanism. The definition of struct setup_data is
+  as follow:
+
+  struct setup_data {
+          u64 next;
+          u32 type;
+          u32 len;
+          u8  data[0];
+  };
+
+  Where, the next is a 64-bit physical pointer to the next node of
+  linked list, the next field of the last node is 0; the type is used
+  to identify the contents of data; the len is the length of data
+  field; the data holds the real payload.
+
+  This list may be modified at a number of points during the bootup
+  process.  Therefore, when modifying this list one should always make
+  sure to consider the case where the linked list already contains
+  entries.
+
+
+**** THE IMAGE CHECKSUM
+
+From boot protocol version 2.08 onwards the CRC-32 is calculated over
+the entire file using the characteristic polynomial 0x04C11DB7 and an
+initial remainder of 0xffffffff.  The checksum is appended to the
+file; therefore the CRC of the file up to the limit specified in the
+syssize field of the header is always 0.
+
+
+**** THE KERNEL COMMAND LINE
+
+The kernel command line has become an important way for the boot
+loader to communicate with the kernel.  Some of its options are also
+relevant to the boot loader itself, see "special command line options"
+below.
+
+The kernel command line is a null-terminated string. The maximum
+length can be retrieved from the field cmdline_size.  Before protocol
+version 2.06, the maximum was 255 characters.  A string that is too
+long will be automatically truncated by the kernel.
+
+If the boot protocol version is 2.02 or later, the address of the
+kernel command line is given by the header field cmd_line_ptr (see
+above.)  This address can be anywhere between the end of the setup
+heap and 0xA0000.
+
+If the protocol version is *not* 2.02 or higher, the kernel
+command line is entered using the following protocol:
+
+        At offset 0x0020 (word), "cmd_line_magic", enter the magic
+        number 0xA33F.
+
+        At offset 0x0022 (word), "cmd_line_offset", enter the offset
+        of the kernel command line (relative to the start of the
+        real-mode kernel).
+        
+        The kernel command line *must* be within the memory region
+        covered by setup_move_size, so you may need to adjust this
+        field.
+
+
+**** MEMORY LAYOUT OF THE REAL-MODE CODE
+
+The real-mode code requires a stack/heap to be set up, as well as
+memory allocated for the kernel command line.  This needs to be done
+in the real-mode accessible memory in bottom megabyte.
+
+It should be noted that modern machines often have a sizable Extended
+BIOS Data Area (EBDA).  As a result, it is advisable to use as little
+of the low megabyte as possible.
+
+Unfortunately, under the following circumstances the 0x90000 memory
+segment has to be used:
+
+        - When loading a zImage kernel ((loadflags & 0x01) == 0).
+        - When loading a 2.01 or earlier boot protocol kernel.
+
+          -> For the 2.00 and 2.01 boot protocols, the real-mode code
+             can be loaded at another address, but it is internally
+             relocated to 0x90000.  For the "old" protocol, the
+             real-mode code must be loaded at 0x90000.
+
+When loading at 0x90000, avoid using memory above 0x9a000.
+
+For boot protocol 2.02 or higher, the command line does not have to be
+located in the same 64K segment as the real-mode setup code; it is
+thus permitted to give the stack/heap the full 64K segment and locate
+the command line above it.
+
+The kernel command line should not be located below the real-mode
+code, nor should it be located in high memory.
+
+
+**** SAMPLE BOOT CONFIGURATION
+
+As a sample configuration, assume the following layout of the real
+mode segment:
+
+    When loading below 0x90000, use the entire segment:
+
+        0x0000-0x7fff   Real mode kernel
+        0x8000-0xdfff   Stack and heap
+        0xe000-0xffff   Kernel command line
+
+    When loading at 0x90000 OR the protocol version is 2.01 or earlier:
+
+        0x0000-0x7fff   Real mode kernel
+        0x8000-0x97ff   Stack and heap
+        0x9800-0x9fff   Kernel command line
+
+Such a boot loader should enter the following fields in the header:
+
+        unsigned long base_ptr; /* base address for real-mode segment */
+
+        if ( setup_sects == 0 ) {
+                setup_sects = 4;
+        }
+
+        if ( protocol >= 0x0200 ) {
+                type_of_loader = <type code>;
+                if ( loading_initrd ) {
+                        ramdisk_image = <initrd_address>;
+                        ramdisk_size = <initrd_size>;
+                }
+
+                if ( protocol >= 0x0202 && loadflags & 0x01 )
+                        heap_end = 0xe000;
+                else
+                        heap_end = 0x9800;
+
+                if ( protocol >= 0x0201 ) {
+                        heap_end_ptr = heap_end - 0x200;
+                        loadflags |= 0x80; /* CAN_USE_HEAP */
+                }
+
+                if ( protocol >= 0x0202 ) {
+                        cmd_line_ptr = base_ptr + heap_end;
+                        strcpy(cmd_line_ptr, cmdline);
+                } else {
+                        cmd_line_magic  = 0xA33F;
+                        cmd_line_offset = heap_end;
+                        setup_move_size = heap_end + strlen(cmdline)+1;
+                        strcpy(base_ptr+cmd_line_offset, cmdline);
+                }
+        } else {
+                /* Very old kernel */
+
+                heap_end = 0x9800;
+
+                cmd_line_magic  = 0xA33F;
+                cmd_line_offset = heap_end;
+
+                /* A very old kernel MUST have its real-mode code
+                   loaded at 0x90000 */
+
+                if ( base_ptr != 0x90000 ) {
+                        /* Copy the real-mode kernel */
+                        memcpy(0x90000, base_ptr, (setup_sects+1)*512);
+                        base_ptr = 0x90000;              /* Relocated */
+                }
+
+                strcpy(0x90000+cmd_line_offset, cmdline);
+
+                /* It is recommended to clear memory up to the 32K mark */
+                memset(0x90000 + (setup_sects+1)*512, 0,
+                       (64-(setup_sects+1))*512);
+        }
+
+
+**** LOADING THE REST OF THE KERNEL
+
+The 32-bit (non-real-mode) kernel starts at offset (setup_sects+1)*512
+in the kernel file (again, if setup_sects == 0 the real value is 4.)
+It should be loaded at address 0x10000 for Image/zImage kernels and
+0x100000 for bzImage kernels.
+
+The kernel is a bzImage kernel if the protocol >= 2.00 and the 0x01
+bit (LOAD_HIGH) in the loadflags field is set:
+
+        is_bzImage = (protocol >= 0x0200) && (loadflags & 0x01);
+        load_address = is_bzImage ? 0x100000 : 0x10000;
+
+Note that Image/zImage kernels can be up to 512K in size, and thus use
+the entire 0x10000-0x90000 range of memory.  This means it is pretty
+much a requirement for these kernels to load the real-mode part at
+0x90000.  bzImage kernels allow much more flexibility.
+
+
+**** SPECIAL COMMAND LINE OPTIONS
+
+If the command line provided by the boot loader is entered by the
+user, the user may expect the following command line options to work.
+They should normally not be deleted from the kernel command line even
+though not all of them are actually meaningful to the kernel.  Boot
+loader authors who need additional command line options for the boot
+loader itself should get them registered in
+Documentation/kernel-parameters.txt to make sure they will not
+conflict with actual kernel options now or in the future.
+
+  vga=<mode>
+        <mode> here is either an integer (in C notation, either
+        decimal, octal, or hexadecimal) or one of the strings
+        "normal" (meaning 0xFFFF), "ext" (meaning 0xFFFE) or "ask"
+        (meaning 0xFFFD).  This value should be entered into the
+        vid_mode field, as it is used by the kernel before the command
+        line is parsed.
+
+  mem=<size>
+        <size> is an integer in C notation optionally followed by
+        (case insensitive) K, M, G, T, P or E (meaning << 10, << 20,
+        << 30, << 40, << 50 or << 60).  This specifies the end of
+        memory to the kernel. This affects the possible placement of
+        an initrd, since an initrd should be placed near end of
+        memory.  Note that this is an option to *both* the kernel and
+        the bootloader!
+
+  initrd=<file>
+        An initrd should be loaded.  The meaning of <file> is
+        obviously bootloader-dependent, and some boot loaders
+        (e.g. LILO) do not have such a command.
+
+In addition, some boot loaders add the following options to the
+user-specified command line:
+
+  BOOT_IMAGE=<file>
+        The boot image which was loaded.  Again, the meaning of <file>
+        is obviously bootloader-dependent.
+
+  auto
+        The kernel was booted without explicit user intervention.
+
+If these options are added by the boot loader, it is highly
+recommended that they are located *first*, before the user-specified
+or configuration-specified command line.  Otherwise, "init=/bin/sh"
+gets confused by the "auto" option.
+
+
+**** RUNNING THE KERNEL
+
+The kernel is started by jumping to the kernel entry point, which is
+located at *segment* offset 0x20 from the start of the real mode
+kernel.  This means that if you loaded your real-mode kernel code at
+0x90000, the kernel entry point is 9020:0000.
+
+At entry, ds = es = ss should point to the start of the real-mode
+kernel code (0x9000 if the code is loaded at 0x90000), sp should be
+set up properly, normally pointing to the top of the heap, and
+interrupts should be disabled.  Furthermore, to guard against bugs in
+the kernel, it is recommended that the boot loader sets fs = gs = ds =
+es = ss.
+
+In our example from above, we would do:
+
+        /* Note: in the case of the "old" kernel protocol, base_ptr must
+           be == 0x90000 at this point; see the previous sample code */
+
+        seg = base_ptr >> 4;
+
+        cli();  /* Enter with interrupts disabled! */
+
+        /* Set up the real-mode kernel stack */
+        _SS = seg;
+        _SP = heap_end;
+
+        _DS = _ES = _FS = _GS = seg;
+        jmp_far(seg+0x20, 0);   /* Run the kernel */
+
+If your boot sector accesses a floppy drive, it is recommended to
+switch off the floppy motor before running the kernel, since the
+kernel boot leaves interrupts off and thus the motor will not be
+switched off, especially if the loaded kernel has the floppy driver as
+a demand-loaded module!
+
+
+**** ADVANCED BOOT LOADER HOOKS
+
+If the boot loader runs in a particularly hostile environment (such as
+LOADLIN, which runs under DOS) it may be impossible to follow the
+standard memory location requirements.  Such a boot loader may use the
+following hooks that, if set, are invoked by the kernel at the
+appropriate time.  The use of these hooks should probably be
+considered an absolutely last resort!
+
+IMPORTANT: All the hooks are required to preserve %esp, %ebp, %esi and
+%edi across invocation.
+
+  realmode_swtch:
+        A 16-bit real mode far subroutine invoked immediately before
+        entering protected mode.  The default routine disables NMI, so
+        your routine should probably do so, too.
+
+  code32_start:
+        A 32-bit flat-mode routine *jumped* to immediately after the
+        transition to protected mode, but before the kernel is
+        uncompressed.  No segments, except CS, are guaranteed to be
+        set up (current kernels do, but older ones do not); you should
+        set them up to BOOT_DS (0x18) yourself.
+
+        After completing your hook, you should jump to the address
+        that was in this field before your boot loader overwrote it
+        (relocated, if appropriate.)
+
+
+**** 32-bit BOOT PROTOCOL
+
+For machine with some new BIOS other than legacy BIOS, such as EFI,
+LinuxBIOS, etc, and kexec, the 16-bit real mode setup code in kernel
+based on legacy BIOS can not be used, so a 32-bit boot protocol needs
+to be defined.
+
+In 32-bit boot protocol, the first step in loading a Linux kernel
+should be to setup the boot parameters (struct boot_params,
+traditionally known as "zero page"). The memory for struct boot_params
+should be allocated and initialized to all zero. Then the setup header
+from offset 0x01f1 of kernel image on should be loaded into struct
+boot_params and examined. The end of setup header can be calculated as
+follow:
+
+        0x0202 + byte value at offset 0x0201
+
+In addition to read/modify/write the setup header of the struct
+boot_params as that of 16-bit boot protocol, the boot loader should
+also fill the additional fields of the struct boot_params as that
+described in zero-page.txt.
+
+After setupping the struct boot_params, the boot loader can load the
+32/64-bit kernel in the same way as that of 16-bit boot protocol.
+
+In 32-bit boot protocol, the kernel is started by jumping to the
+32-bit kernel entry point, which is the start address of loaded
+32/64-bit kernel.
+
+At entry, the CPU must be in 32-bit protected mode with paging
+disabled; a GDT must be loaded with the descriptors for selectors
+__BOOT_CS(0x10) and __BOOT_DS(0x18); both descriptors must be 4G flat
+segment; __BOOS_CS must have execute/read permission, and __BOOT_DS
+must have read/write permission; CS must be __BOOT_CS and DS, ES, SS
+must be __BOOT_DS; interrupt must be disabled; %esi must hold the base
+address of the struct boot_params; %ebp, %edi and %ebx must be zero.
diff --git a/Documentation/x86/i386/usb-legacy-support.txt b/Documentation/x86/i386/usb-legacy-support.txt
new file mode 100644
index 000000000000..1894cdfc69d9
--- /dev/null
+++ b/Documentation/x86/i386/usb-legacy-support.txt
@@ -0,0 +1,44 @@
+USB Legacy support
+~~~~~~~~~~~~~~~~~~
+
+Vojtech Pavlik <vojtech@suse.cz>, January 2004
+
+
+Also known as "USB Keyboard" or "USB Mouse support" in the BIOS Setup is a
+feature that allows one to use the USB mouse and keyboard as if they were
+their classic PS/2 counterparts.  This means one can use an USB keyboard to
+type in LILO for example.
+
+It has several drawbacks, though:
+
+1) On some machines, the emulated PS/2 mouse takes over even when no USB
+   mouse is present and a real PS/2 mouse is present.  In that case the extra
+   features (wheel, extra buttons, touchpad mode) of the real PS/2 mouse may
+   not be available.
+
+2) If CONFIG_HIGHMEM64G is enabled, the PS/2 mouse emulation can cause
+   system crashes, because the SMM BIOS is not expecting to be in PAE mode.
+   The Intel E7505 is a typical machine where this happens.
+
+3) If AMD64 64-bit mode is enabled, again system crashes often happen,
+   because the SMM BIOS isn't expecting the CPU to be in 64-bit mode.  The
+   BIOS manufacturers only test with Windows, and Windows doesn't do 64-bit
+   yet.
+
+Solutions:
+
+Problem 1) can be solved by loading the USB drivers prior to loading the
+PS/2 mouse driver. Since the PS/2 mouse driver is in 2.6 compiled into
+the kernel unconditionally, this means the USB drivers need to be
+compiled-in, too.
+
+Problem 2) can currently only be solved by either disabling HIGHMEM64G
+in the kernel config or USB Legacy support in the BIOS. A BIOS update
+could help, but so far no such update exists.
+
+Problem 3) is usually fixed by a BIOS update. Check the board
+manufacturers web site. If an update is not available, disable USB
+Legacy support in the BIOS. If this alone doesn't help, try also adding
+idle=poll on the kernel command line. The BIOS may be entering the SMM
+on the HLT instruction as well.
+
diff --git a/Documentation/x86/i386/zero-page.txt b/Documentation/x86/i386/zero-page.txt
new file mode 100644
index 000000000000..169ad423a3d1
--- /dev/null
+++ b/Documentation/x86/i386/zero-page.txt
@@ -0,0 +1,31 @@
+The additional fields in struct boot_params as a part of 32-bit boot
+protocol of kernel. These should be filled by bootloader or 16-bit
+real-mode setup code of the kernel. References/settings to it mainly
+are in:
+
+  include/asm-x86/bootparam.h
+
+
+Offset  Proto   Name            Meaning
+/Size
+
+000/040 ALL     screen_info     Text mode or frame buffer information
+                                (struct screen_info)
+040/014 ALL     apm_bios_info   APM BIOS information (struct apm_bios_info)
+060/010 ALL     ist_info        Intel SpeedStep (IST) BIOS support information
+                                (struct ist_info)
+080/010 ALL     hd0_info        hd0 disk parameter, OBSOLETE!!
+090/010 ALL     hd1_info        hd1 disk parameter, OBSOLETE!!
+0A0/010 ALL     sys_desc_table  System description table (struct sys_desc_table)
+140/080 ALL     edid_info       Video mode setup (struct edid_info)
+1C0/020 ALL     efi_info        EFI 32 information (struct efi_info)
+1E0/004 ALL     alk_mem_k       Alternative mem check, in KB
+1E4/004 ALL     scratch         Scratch field for the kernel setup code
+1E8/001 ALL     e820_entries    Number of entries in e820_map (below)
+1E9/001 ALL     eddbuf_entries  Number of entries in eddbuf (below)
+1EA/001 ALL     edd_mbr_sig_buf_entries Number of entries in edd_mbr_sig_buffer
+                                (below)
+290/040 ALL     edd_mbr_sig_buffer EDD MBR signatures
+2D0/A00 ALL     e820_map        E820 memory map table
+                                (array of struct e820entry)
+D00/1EC ALL     eddbuf          EDD data (array of struct edd_info)
diff --git a/Documentation/x86/x86_64/00-INDEX b/Documentation/x86/x86_64/00-INDEX
new file mode 100644
index 000000000000..92fc20ab5f0e
--- /dev/null
+++ b/Documentation/x86/x86_64/00-INDEX
@@ -0,0 +1,16 @@
+00-INDEX
+        - This file
+boot-options.txt
+        - AMD64-specific boot options.
+cpu-hotplug-spec
+        - Firmware support for CPU hotplug under Linux/x86-64
+fake-numa-for-cpusets
+        - Using numa=fake and CPUSets for Resource Management
+kernel-stacks
+        - Context-specific per-processor interrupt stacks.
+machinecheck
+        - Configurable sysfs parameters for the x86-64 machine check code.
+mm.txt
+        - Memory layout of x86-64 (4 level page tables, 46 bits physical).
+uefi.txt
+        - Booting Linux via Unified Extensible Firmware Interface.
diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt
new file mode 100644
index 000000000000..b0c7b6c4abda
--- /dev/null
+++ b/Documentation/x86/x86_64/boot-options.txt
@@ -0,0 +1,314 @@
+AMD64 specific boot options
+
+There are many others (usually documented in driver documentation), but
+only the AMD64 specific ones are listed here.
+
+Machine check
+
+   mce=off disable machine check
+   mce=bootlog Enable logging of machine checks left over from booting.
+               Disabled by default on AMD because some BIOS leave bogus ones.
+               If your BIOS doesn't do that it's a good idea to enable though
+               to make sure you log even machine check events that result
+               in a reboot. On Intel systems it is enabled by default.
+   mce=nobootlog
+                Disable boot machine check logging.
+   mce=tolerancelevel (number)
+                0: always panic on uncorrected errors, log corrected errors
+                1: panic or SIGBUS on uncorrected errors, log corrected errors
+                2: SIGBUS or log uncorrected errors, log corrected errors
+                3: never panic or SIGBUS, log all errors (for testing only)
+                Default is 1
+                Can be also set using sysfs which is preferable.
+
+   nomce (for compatibility with i386): same as mce=off
+
+   Everything else is in sysfs now.
+
+APICs
+
+   apic          Use IO-APIC. Default
+
+   noapic        Don't use the IO-APIC.
+
+   disableapic   Don't use the local APIC
+
+   nolapic       Don't use the local APIC (alias for i386 compatibility)
+
+   pirq=...      See Documentation/i386/IO-APIC.txt
+
+   noapictimer   Don't set up the APIC timer
+
+   no_timer_check Don't check the IO-APIC timer. This can work around
+                 problems with incorrect timer initialization on some boards.
+
+   apicmaintimer Run time keeping from the local APIC timer instead
+                 of using the PIT/HPET interrupt for this. This is useful
+                 when the PIT/HPET interrupts are unreliable.
+
+   noapicmaintimer  Don't do time keeping using the APIC timer.
+                 Useful when this option was auto selected, but doesn't work.
+
+   apicpmtimer
+                 Do APIC timer calibration using the pmtimer. Implies
+                 apicmaintimer. Useful when your PIT timer is totally
+                 broken.
+
+   disable_8254_timer / enable_8254_timer
+                 Enable interrupt 0 timer routing over the 8254 in addition to over
+                 the IO-APIC. The kernel tries to set a sensible default.
+
+Early Console
+
+   syntax: earlyprintk=vga
+           earlyprintk=serial[,ttySn[,baudrate]]
+
+   The early console is useful when the kernel crashes before the
+   normal console is initialized. It is not enabled by
+   default because it has some cosmetic problems.
+   Append ,keep to not disable it when the real console takes over.
+   Only vga or serial at a time, not both.
+   Currently only ttyS0 and ttyS1 are supported.
+   Interaction with the standard serial driver is not very good.
+   The VGA output is eventually overwritten by the real console.
+
+Timing
+
+  notsc
+  Don't use the CPU time stamp counter to read the wall time.
+  This can be used to work around timing problems on multiprocessor systems
+  with not properly synchronized CPUs.
+
+  report_lost_ticks
+  Report when timer interrupts are lost because some code turned off
+  interrupts for too long.
+
+  nmi_watchdog=NUMBER[,panic]
+  NUMBER can be:
+  0 don't use an NMI watchdog
+  1 use the IO-APIC timer for the NMI watchdog
+  2 use the local APIC for the NMI watchdog using a performance counter. Note
+  This will use one performance counter and the local APIC's performance
+  vector.
+  When panic is specified panic when an NMI watchdog timeout occurs.
+  This is useful when you use a panic=... timeout and need the box
+  quickly up again.
+
+  nohpet
+  Don't use the HPET timer.
+
+Idle loop
+
+  idle=poll
+  Don't do power saving in the idle loop using HLT, but poll for rescheduling
+  event. This will make the CPUs eat a lot more power, but may be useful
+  to get slightly better performance in multiprocessor benchmarks. It also
+  makes some profiling using performance counters more accurate.
+  Please note that on systems with MONITOR/MWAIT support (like Intel EM64T
+  CPUs) this option has no performance advantage over the normal idle loop.
+  It may also interact badly with hyperthreading.
+
+Rebooting
+
+   reboot=b[ios] | t[riple] | k[bd] | a[cpi] | e[fi] [, [w]arm | [c]old]
+   bios   Use the CPU reboot vector for warm reset
+   warm   Don't set the cold reboot flag
+   cold   Set the cold reboot flag
+   triple Force a triple fault (init)
+   kbd    Use the keyboard controller. cold reset (default)
+   acpi   Use the ACPI RESET_REG in the FADT. If ACPI is not configured or the
+          ACPI reset does not work, the reboot path attempts the reset using
+          the keyboard controller.
+   efi    Use efi reset_system runtime service. If EFI is not configured or the
+          EFI reset does not work, the reboot path attempts the reset using
+          the keyboard controller.
+
+   Using warm reset will be much faster especially on big memory
+   systems because the BIOS will not go through the memory check.
+   Disadvantage is that not all hardware will be completely reinitialized
+   on reboot so there may be boot problems on some systems.
+
+   reboot=force
+
+   Don't stop other CPUs on reboot. This can make reboot more reliable
+   in some cases.
+
+Non Executable Mappings
+
+  noexec=on|off
+
+  on      Enable(default)
+  off     Disable
+
+SMP
+
+  additional_cpus=NUM Allow NUM more CPUs for hotplug
+                 (defaults are specified by the BIOS, see Documentation/x86_64/cpu-hotplug-spec)
+
+NUMA
+
+  numa=off      Only set up a single NUMA node spanning all memory.
+
+  numa=noacpi   Don't parse the SRAT table for NUMA setup
+
+  numa=fake=CMDLINE
+                If a number, fakes CMDLINE nodes and ignores NUMA setup of the
+                actual machine.  Otherwise, system memory is configured
+                depending on the sizes and coefficients listed.  For example:
+                        numa=fake=2*512,1024,4*256,*128
+                gives two 512M nodes, a 1024M node, four 256M nodes, and the
+                rest split into 128M chunks.  If the last character of CMDLINE
+                is a *, the remaining memory is divided up equally among its
+                coefficient:
+                        numa=fake=2*512,2*
+                gives two 512M nodes and the rest split into two nodes.
+                Otherwise, the remaining system RAM is allocated to an
+                additional node.
+
+  numa=hotadd=percent
+                Only allow hotadd memory to preallocate page structures upto
+                percent of already available memory.
+                numa=hotadd=0 will disable hotadd memory.
+
+ACPI
+
+  acpi=off      Don't enable ACPI
+  acpi=ht       Use ACPI boot table parsing, but don't enable ACPI
+                interpreter
+  acpi=force    Force ACPI on (currently not needed)
+
+  acpi=strict   Disable out of spec ACPI workarounds.
+
+  acpi_sci={edge,level,high,low}  Set up ACPI SCI interrupt.
+
+  acpi=noirq    Don't route interrupts
+
+PCI
+
+  pci=off       Don't use PCI
+  pci=conf1     Use conf1 access.
+  pci=conf2     Use conf2 access.
+  pci=rom       Assign ROMs.
+  pci=assign-busses    Assign busses
+  pci=irqmask=MASK             Set PCI interrupt mask to MASK
+  pci=lastbus=NUMBER           Scan upto NUMBER busses, no matter what the mptable says.
+  pci=noacpi            Don't use ACPI to set up PCI interrupt routing.
+
+IOMMU (input/output memory management unit)
+
+ Currently four x86-64 PCI-DMA mapping implementations exist:
+
+   1. <arch/x86_64/kernel/pci-nommu.c>: use no hardware/software IOMMU at all
+      (e.g. because you have < 3 GB memory).
+      Kernel boot message: "PCI-DMA: Disabling IOMMU"
+
+   2. <arch/x86_64/kernel/pci-gart.c>: AMD GART based hardware IOMMU.
+      Kernel boot message: "PCI-DMA: using GART IOMMU"
+
+   3. <arch/x86_64/kernel/pci-swiotlb.c> : Software IOMMU implementation. Used
+      e.g. if there is no hardware IOMMU in the system and it is need because
+      you have >3GB memory or told the kernel to us it (iommu=soft))
+      Kernel boot message: "PCI-DMA: Using software bounce buffering
+      for IO (SWIOTLB)"
+
+   4. <arch/x86_64/pci-calgary.c> : IBM Calgary hardware IOMMU. Used in IBM
+      pSeries and xSeries servers. This hardware IOMMU supports DMA address
+      mapping with memory protection, etc.
+      Kernel boot message: "PCI-DMA: Using Calgary IOMMU"
+
+ iommu=[<size>][,noagp][,off][,force][,noforce][,leak[=<nr_of_leak_pages>]
+        [,memaper[=<order>]][,merge][,forcesac][,fullflush][,nomerge]
+        [,noaperture][,calgary]
+
+  General iommu options:
+    off                Don't initialize and use any kind of IOMMU.
+    noforce            Don't force hardware IOMMU usage when it is not needed.
+                       (default).
+    force              Force the use of the hardware IOMMU even when it is
+                       not actually needed (e.g. because < 3 GB memory).
+    soft               Use software bounce buffering (SWIOTLB) (default for
+                       Intel machines). This can be used to prevent the usage
+                       of an available hardware IOMMU.
+
+  iommu options only relevant to the AMD GART hardware IOMMU:
+    <size>             Set the size of the remapping area in bytes.
+    allowed            Overwrite iommu off workarounds for specific chipsets.
+    fullflush          Flush IOMMU on each allocation (default).
+    nofullflush        Don't use IOMMU fullflush.
+    leak               Turn on simple iommu leak tracing (only when
+                       CONFIG_IOMMU_LEAK is on). Default number of leak pages
+                       is 20.
+    memaper[=<order>]  Allocate an own aperture over RAM with size 32MB<<order.
+                       (default: order=1, i.e. 64MB)
+    merge              Do scatter-gather (SG) merging. Implies "force"
+                       (experimental).
+    nomerge            Don't do scatter-gather (SG) merging.
+    noaperture         Ask the IOMMU not to touch the aperture for AGP.
+    forcesac           Force single-address cycle (SAC) mode for masks <40bits
+                       (experimental).
+    noagp              Don't initialize the AGP driver and use full aperture.
+    allowdac           Allow double-address cycle (DAC) mode, i.e. DMA >4GB.
+                       DAC is used with 32-bit PCI to push a 64-bit address in
+                       two cycles. When off all DMA over >4GB is forced through
+                       an IOMMU or software bounce buffering.
+    nodac              Forbid DAC mode, i.e. DMA >4GB.
+    panic              Always panic when IOMMU overflows.
+    calgary            Use the Calgary IOMMU if it is available
+
+  iommu options only relevant to the software bounce buffering (SWIOTLB) IOMMU
+  implementation:
+    swiotlb=<pages>[,force]
+    <pages>            Prereserve that many 128K pages for the software IO
+                       bounce buffering.
+    force              Force all IO through the software TLB.
+
+  Settings for the IBM Calgary hardware IOMMU currently found in IBM
+  pSeries and xSeries machines:
+
+    calgary=[64k,128k,256k,512k,1M,2M,4M,8M]
+    calgary=[translate_empty_slots]
+    calgary=[disable=<PCI bus number>]
+    panic              Always panic when IOMMU overflows
+
+    64k,...,8M - Set the size of each PCI slot's translation table
+    when using the Calgary IOMMU. This is the size of the translation
+    table itself in main memory. The smallest table, 64k, covers an IO
+    space of 32MB; the largest, 8MB table, can cover an IO space of
+    4GB. Normally the kernel will make the right choice by itself.
+
+    translate_empty_slots - Enable translation even on slots that have
+    no devices attached to them, in case a device will be hotplugged
+    in the future.
+
+    disable=<PCI bus number> - Disable translation on a given PHB. For
+    example, the built-in graphics adapter resides on the first bridge
+    (PCI bus number 0); if translation (isolation) is enabled on this
+    bridge, X servers that access the hardware directly from user
+    space might stop working. Use this option if you have devices that
+    are accessed from userspace directly on some PCI host bridge.
+
+Debugging
+
+  oops=panic    Always panic on oopses. Default is to just kill the process,
+                but there is a small probability of deadlocking the machine.
+                This will also cause panics on machine check exceptions.
+                Useful together with panic=30 to trigger a reboot.
+
+  kstack=N      Print N words from the kernel stack in oops dumps.
+
+  pagefaulttrace  Dump all page faults. Only useful for extreme debugging
+                and will create a lot of output.
+
+  call_trace=[old|both|newfallback|new]
+                old: use old inexact backtracer
+                new: use new exact dwarf2 unwinder
+                both: print entries from both
+                newfallback: use new unwinder but fall back to old if it gets
+                        stuck (default)
+
+Miscellaneous
+
+        nogbpages
+                Do not use GB pages for kernel direct mappings.
+        gbpages
+                Use GB pages for kernel direct mappings.
diff --git a/Documentation/x86/x86_64/cpu-hotplug-spec b/Documentation/x86/x86_64/cpu-hotplug-spec
new file mode 100644
index 000000000000..3c23e0587db3
--- /dev/null
+++ b/Documentation/x86/x86_64/cpu-hotplug-spec
@@ -0,0 +1,21 @@
+Firmware support for CPU hotplug under Linux/x86-64
+---------------------------------------------------
+
+Linux/x86-64 supports CPU hotplug now. For various reasons Linux wants to
+know in advance of boot time the maximum number of CPUs that could be plugged
+into the system. ACPI 3.0 currently has no official way to supply
+this information from the firmware to the operating system.
+
+In ACPI each CPU needs an LAPIC object in the MADT table (5.2.11.5 in the
+ACPI 3.0 specification).  ACPI already has the concept of disabled LAPIC
+objects by setting the Enabled bit in the LAPIC object to zero.
+
+For CPU hotplug Linux/x86-64 expects now that any possible future hotpluggable
+CPU is already available in the MADT. If the CPU is not available yet
+it should have its LAPIC Enabled bit set to 0. Linux will use the number
+of disabled LAPICs to compute the maximum number of future CPUs.
+
+In the worst case the user can overwrite this choice using a command line
+option (additional_cpus=...), but it is recommended to supply the correct
+number (or a reasonable approximation of it, with erring towards more not less)
+in the MADT to avoid manual configuration.
diff --git a/Documentation/x86/x86_64/fake-numa-for-cpusets b/Documentation/x86/x86_64/fake-numa-for-cpusets
new file mode 100644
index 000000000000..d1a985c5b00a
--- /dev/null
+++ b/Documentation/x86/x86_64/fake-numa-for-cpusets
@@ -0,0 +1,66 @@
+Using numa=fake and CPUSets for Resource Management
+Written by David Rientjes <rientjes@cs.washington.edu>
+
+This document describes how the numa=fake x86_64 command-line option can be used
+in conjunction with cpusets for coarse memory management.  Using this feature,
+you can create fake NUMA nodes that represent contiguous chunks of memory and
+assign them to cpusets and their attached tasks.  This is a way of limiting the
+amount of system memory that are available to a certain class of tasks.
+
+For more information on the features of cpusets, see Documentation/cpusets.txt.
+There are a number of different configurations you can use for your needs.  For
+more information on the numa=fake command line option and its various ways of
+configuring fake nodes, see Documentation/x86_64/boot-options.txt.
+
+For the purposes of this introduction, we'll assume a very primitive NUMA
+emulation setup of "numa=fake=4*512,".  This will split our system memory into
+four equal chunks of 512M each that we can now use to assign to cpusets.  As
+you become more familiar with using this combination for resource control,
+you'll determine a better setup to minimize the number of nodes you have to deal
+with.
+
+A machine may be split as follows with "numa=fake=4*512," as reported by dmesg:
+
+        Faking node 0 at 0000000000000000-0000000020000000 (512MB)
+        Faking node 1 at 0000000020000000-0000000040000000 (512MB)
+        Faking node 2 at 0000000040000000-0000000060000000 (512MB)
+        Faking node 3 at 0000000060000000-0000000080000000 (512MB)
+        ...
+        On node 0 totalpages: 130975
+        On node 1 totalpages: 131072
+        On node 2 totalpages: 131072
+        On node 3 totalpages: 131072
+
+Now following the instructions for mounting the cpusets filesystem from
+Documentation/cpusets.txt, you can assign fake nodes (i.e. contiguous memory
+address spaces) to individual cpusets:
+
+        [root@xroads /]# mkdir exampleset
+        [root@xroads /]# mount -t cpuset none exampleset
+        [root@xroads /]# mkdir exampleset/ddset
+        [root@xroads /]# cd exampleset/ddset
+        [root@xroads /exampleset/ddset]# echo 0-1 > cpus
+        [root@xroads /exampleset/ddset]# echo 0-1 > mems
+
+Now this cpuset, 'ddset', will only allowed access to fake nodes 0 and 1 for
+memory allocations (1G).
+
+You can now assign tasks to these cpusets to limit the memory resources
+available to them according to the fake nodes assigned as mems:
+
+        [root@xroads /exampleset/ddset]# echo $$ > tasks
+        [root@xroads /exampleset/ddset]# dd if=/dev/zero of=tmp bs=1024 count=1G
+        [1] 13425
+
+Notice the difference between the system memory usage as reported by
+/proc/meminfo between the restricted cpuset case above and the unrestricted
+case (i.e. running the same 'dd' command without assigning it to a fake NUMA
+cpuset):
+                                Unrestricted    Restricted
+        MemTotal:               3091900 kB      3091900 kB
+        MemFree:                  42113 kB      1513236 kB
+
+This allows for coarse memory management for the tasks you assign to particular
+cpusets.  Since cpusets can form a hierarchy, you can create some pretty
+interesting combinations of use-cases for various classes of tasks for your
+memory management needs.
diff --git a/Documentation/x86/x86_64/kernel-stacks b/Documentation/x86/x86_64/kernel-stacks
new file mode 100644
index 000000000000..5ad65d51fb95
--- /dev/null
+++ b/Documentation/x86/x86_64/kernel-stacks
@@ -0,0 +1,99 @@
+Most of the text from Keith Owens, hacked by AK
+
+x86_64 page size (PAGE_SIZE) is 4K.
+
+Like all other architectures, x86_64 has a kernel stack for every
+active thread.  These thread stacks are THREAD_SIZE (2*PAGE_SIZE) big.
+These stacks contain useful data as long as a thread is alive or a
+zombie. While the thread is in user space the kernel stack is empty
+except for the thread_info structure at the bottom.
+
+In addition to the per thread stacks, there are specialized stacks
+associated with each CPU.  These stacks are only used while the kernel
+is in control on that CPU; when a CPU returns to user space the
+specialized stacks contain no useful data.  The main CPU stacks are:
+
+* Interrupt stack.  IRQSTACKSIZE
+
+  Used for external hardware interrupts.  If this is the first external
+  hardware interrupt (i.e. not a nested hardware interrupt) then the
+  kernel switches from the current task to the interrupt stack.  Like
+  the split thread and interrupt stacks on i386 (with CONFIG_4KSTACKS),
+  this gives more room for kernel interrupt processing without having
+  to increase the size of every per thread stack.
+
+  The interrupt stack is also used when processing a softirq.
+
+Switching to the kernel interrupt stack is done by software based on a
+per CPU interrupt nest counter. This is needed because x86-64 "IST"
+hardware stacks cannot nest without races.
+
+x86_64 also has a feature which is not available on i386, the ability
+to automatically switch to a new stack for designated events such as
+double fault or NMI, which makes it easier to handle these unusual
+events on x86_64.  This feature is called the Interrupt Stack Table
+(IST).  There can be up to 7 IST entries per CPU. The IST code is an
+index into the Task State Segment (TSS). The IST entries in the TSS
+point to dedicated stacks; each stack can be a different size.
+
+An IST is selected by a non-zero value in the IST field of an
+interrupt-gate descriptor.  When an interrupt occurs and the hardware
+loads such a descriptor, the hardware automatically sets the new stack
+pointer based on the IST value, then invokes the interrupt handler.  If
+software wants to allow nested IST interrupts then the handler must
+adjust the IST values on entry to and exit from the interrupt handler.
+(This is occasionally done, e.g. for debug exceptions.)
+
+Events with different IST codes (i.e. with different stacks) can be
+nested.  For example, a debug interrupt can safely be interrupted by an
+NMI.  arch/x86_64/kernel/entry.S::paranoidentry adjusts the stack
+pointers on entry to and exit from all IST events, in theory allowing
+IST events with the same code to be nested.  However in most cases, the
+stack size allocated to an IST assumes no nesting for the same code.
+If that assumption is ever broken then the stacks will become corrupt.
+
+The currently assigned IST stacks are :-
+
+* STACKFAULT_STACK.  EXCEPTION_STKSZ (PAGE_SIZE).
+
+  Used for interrupt 12 - Stack Fault Exception (#SS).
+
+  This allows the CPU to recover from invalid stack segments. Rarely
+  happens.
+
+* DOUBLEFAULT_STACK.  EXCEPTION_STKSZ (PAGE_SIZE).
+
+  Used for interrupt 8 - Double Fault Exception (#DF).
+
+  Invoked when handling one exception causes another exception. Happens
+  when the kernel is very confused (e.g. kernel stack pointer corrupt).
+  Using a separate stack allows the kernel to recover from it well enough
+  in many cases to still output an oops.
+
+* NMI_STACK.  EXCEPTION_STKSZ (PAGE_SIZE).
+
+  Used for non-maskable interrupts (NMI).
+
+  NMI can be delivered at any time, including when the kernel is in the
+  middle of switching stacks.  Using IST for NMI events avoids making
+  assumptions about the previous state of the kernel stack.
+
+* DEBUG_STACK.  DEBUG_STKSZ
+
+  Used for hardware debug interrupts (interrupt 1) and for software
+  debug interrupts (INT3).
+
+  When debugging a kernel, debug interrupts (both hardware and
+  software) can occur at any time.  Using IST for these interrupts
+  avoids making assumptions about the previous state of the kernel
+  stack.
+
+* MCE_STACK.  EXCEPTION_STKSZ (PAGE_SIZE).
+
+  Used for interrupt 18 - Machine Check Exception (#MC).
+
+  MCE can be delivered at any time, including when the kernel is in the
+  middle of switching stacks.  Using IST for MCE events avoids making
+  assumptions about the previous state of the kernel stack.
+
+For more details see the Intel IA32 or AMD AMD64 architecture manuals.
diff --git a/Documentation/x86/x86_64/machinecheck b/Documentation/x86/x86_64/machinecheck
new file mode 100644
index 000000000000..a05e58e7b159
--- /dev/null
+++ b/Documentation/x86/x86_64/machinecheck
@@ -0,0 +1,77 @@
+
+Configurable sysfs parameters for the x86-64 machine check code.
+
+Machine checks report internal hardware error conditions detected
+by the CPU. Uncorrected errors typically cause a machine check
+(often with panic), corrected ones cause a machine check log entry.
+
+Machine checks are organized in banks (normally associated with
+a hardware subsystem) and subevents in a bank. The exact meaning
+of the banks and subevent is CPU specific.
+
+mcelog knows how to decode them.
+
+When you see the "Machine check errors logged" message in the system
+log then mcelog should run to collect and decode machine check entries
+from /dev/mcelog. Normally mcelog should be run regularly from a cronjob.
+
+Each CPU has a directory in /sys/devices/system/machinecheck/machinecheckN
+(N = CPU number)
+
+The directory contains some configurable entries:
+
+Entries:
+
+bankNctl
+(N bank number)
+        64bit Hex bitmask enabling/disabling specific subevents for bank N
+        When a bit in the bitmask is zero then the respective
+        subevent will not be reported.
+        By default all events are enabled.
+        Note that BIOS maintain another mask to disable specific events
+        per bank.  This is not visible here
+
+The following entries appear for each CPU, but they are truly shared
+between all CPUs.
+
+check_interval
+        How often to poll for corrected machine check errors, in seconds
+        (Note output is hexademical). Default 5 minutes.  When the poller
+        finds MCEs it triggers an exponential speedup (poll more often) on
+        the polling interval.  When the poller stops finding MCEs, it
+        triggers an exponential backoff (poll less often) on the polling
+        interval. The check_interval variable is both the initial and
+        maximum polling interval.
+
+tolerant
+        Tolerance level. When a machine check exception occurs for a non
+        corrected machine check the kernel can take different actions.
+        Since machine check exceptions can happen any time it is sometimes
+        risky for the kernel to kill a process because it defies
+        normal kernel locking rules. The tolerance level configures
+        how hard the kernel tries to recover even at some risk of
+        deadlock.  Higher tolerant values trade potentially better uptime
+        with the risk of a crash or even corruption (for tolerant >= 3).
+
+        0: always panic on uncorrected errors, log corrected errors
+        1: panic or SIGBUS on uncorrected errors, log corrected errors
+        2: SIGBUS or log uncorrected errors, log corrected errors
+        3: never panic or SIGBUS, log all errors (for testing only)
+
+        Default: 1
+
+        Note this only makes a difference if the CPU allows recovery
+        from a machine check exception. Current x86 CPUs generally do not.
+
+trigger
+        Program to run when a machine check event is detected.
+        This is an alternative to running mcelog regularly from cron
+        and allows to detect events faster.
+
+TBD document entries for AMD threshold interrupt configuration
+
+For more details about the x86 machine check architecture
+see the Intel and AMD architecture manuals from their developer websites.
+
+For more details about the architecture see
+see http://one.firstfloor.org/~andi/mce.pdf
diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt
new file mode 100644
index 000000000000..b89b6d2bebfa
--- /dev/null
+++ b/Documentation/x86/x86_64/mm.txt
@@ -0,0 +1,29 @@
+
+<previous description obsolete, deleted>
+
+Virtual memory map with 4 level page tables:
+
+0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm
+hole caused by [48:63] sign extension
+ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole
+ffff810000000000 - ffffc0ffffffffff (=46 bits) direct mapping of all phys. memory
+ffffc10000000000 - ffffc1ffffffffff (=40 bits) hole
+ffffc20000000000 - ffffe1ffffffffff (=45 bits) vmalloc/ioremap space
+ffffe20000000000 - ffffe2ffffffffff (=40 bits) virtual memory map (1TB)
+... unused hole ...
+ffffffff80000000 - ffffffff82800000 (=40 MB)   kernel text mapping, from phys 0
+... unused hole ...
+ffffffff88000000 - fffffffffff00000 (=1919 MB) module mapping space
+
+The direct mapping covers all memory in the system up to the highest
+memory address (this means in some cases it can also include PCI memory
+holes).
+
+vmalloc space is lazily synchronized into the different PML4 pages of
+the processes using the page fault handler, with init_level4_pgt as
+reference.
+
+Current X86-64 implementations only support 40 bits of address space,
+but we support up to 46 bits. This expands into MBZ space in the page tables.
+
+-Andi Kleen, Jul 2004
diff --git a/Documentation/x86/x86_64/uefi.txt b/Documentation/x86/x86_64/uefi.txt
new file mode 100644
index 000000000000..7d77120a5184
--- /dev/null
+++ b/Documentation/x86/x86_64/uefi.txt
@@ -0,0 +1,38 @@
+General note on [U]EFI x86_64 support
+-------------------------------------
+
+The nomenclature EFI and UEFI are used interchangeably in this document.
+
+Although the tools below are _not_ needed for building the kernel,
+the needed bootloader support and associated tools for x86_64 platforms
+with EFI firmware and specifications are listed below.
+
+1. UEFI specification:  http://www.uefi.org
+
+2. Booting Linux kernel on UEFI x86_64 platform requires bootloader
+   support. Elilo with x86_64 support can be used.
+
+3. x86_64 platform with EFI/UEFI firmware.
+
+Mechanics:
+---------
+- Build the kernel with the following configuration.
+        CONFIG_FB_EFI=y
+        CONFIG_FRAMEBUFFER_CONSOLE=y
+  If EFI runtime services are expected, the following configuration should
+  be selected.
+        CONFIG_EFI=y
+        CONFIG_EFI_VARS=y or m          # optional
+- Create a VFAT partition on the disk
+- Copy the following to the VFAT partition:
+        elilo bootloader with x86_64 support, elilo configuration file,
+        kernel image built in first step and corresponding
+        initrd. Instructions on building elilo  and its dependencies
+        can be found in the elilo sourceforge project.
+- Boot to EFI shell and invoke elilo choosing the kernel image built
+  in first step.
+- If some or all EFI runtime services don't work, you can try following
+  kernel command line parameters to turn off some or all EFI runtime
+  services.
+        noefi           turn off all EFI runtime services
+        reboot_type=k   turn off EFI reboot runtime service