Commit fd8773f9 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

arch: remove frv port

The Fujitsu FRV kernel port has been around for a long time, but has not
seen regular updates in several years and instead was marked 'Orphaned'
in 2016 by long-time maintainer David Howells.

The SoC product line apparently is apparently still around in the form
of the Socionext Milbeaut image processor, but this one no longer uses
the FRV CPU cores.

This removes all FRV specific files from the kernel.

Link: http://www.socionext.com/en/products/assp/milbeaut/


Cc: David Howells <dhowells@redhat.com>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 739d875d
......@@ -172,8 +172,6 @@ fmc/
- information about the FMC bus abstraction
fpga/
- FPGA Manager Core.
frv/
- Fujitsu FR-V Linux documentation.
futex-requeue-pi.txt
- info on requeueing of tasks from a non-PI futex to a PI futex
gcc-plugins.txt
......
================================
Fujitsu FR-V LINUX DOCUMENTATION
================================
This directory contains documentation for the Fujitsu FR-V CPU architecture
port of Linux.
The following documents are available:
(*) features.txt
A description of the basic features inherent in this architecture port.
(*) configuring.txt
A summary of the configuration options particular to this architecture.
(*) booting.txt
A description of how to boot the kernel image and a summary of the kernel
command line options.
(*) gdbstub.txt
A description of how to debug the kernel using GDB attached by serial
port, and a summary of the services available.
(*) mmu-layout.txt
A description of the virtual and physical memory layout used in the
MMU linux kernel, and the registers used to support it.
(*) gdbinit
An example .gdbinit file for use with GDB. It includes macros for viewing
MMU state on the FR451. See mmu-layout.txt for more information.
(*) clock.txt
A description of the CPU clock scaling interface.
(*) atomic-ops.txt
A description of how the FR-V kernel's atomic operations work.
=====================================
FUJITSU FR-V KERNEL ATOMIC OPERATIONS
=====================================
On the FR-V CPUs, there is only one atomic Read-Modify-Write operation: the SWAP/SWAPI
instruction. Unfortunately, this alone can't be used to implement the following operations:
(*) Atomic add to memory
(*) Atomic subtract from memory
(*) Atomic bit modification (set, clear or invert)
(*) Atomic compare and exchange
On such CPUs, the standard way of emulating such operations in uniprocessor mode is to disable
interrupts, but on the FR-V CPUs, modifying the PSR takes a lot of clock cycles, and it has to be
done twice. This means the CPU runs for a relatively long time with interrupts disabled,
potentially having a great effect on interrupt latency.
=============
NEW ALGORITHM
=============
To get around this, the following algorithm has been implemented. It operates in a way similar to
the LL/SC instruction pairs supported on a number of platforms.
(*) The CCCR.CC3 register is reserved within the kernel to act as an atomic modify abort flag.
(*) In the exception prologues run on kernel->kernel entry, CCCR.CC3 is set to 0 (Undefined
state).
(*) All atomic operations can then be broken down into the following algorithm:
(1) Set ICC3.Z to true and set CC3 to True (ORCC/CKEQ/ORCR).
(2) Load the value currently in the memory to be modified into a register.
(3) Make changes to the value.
(4) If CC3 is still True, simultaneously and atomically (by VLIW packing):
(a) Store the modified value back to memory.
(b) Set ICC3.Z to false (CORCC on GR29 is sufficient for this - GR29 holds the current
task pointer in the kernel, and so is guaranteed to be non-zero).
(5) If ICC3.Z is still true, go back to step (1).
This works in a non-SMP environment because any interrupt or other exception that happens between
steps (1) and (4) will set CC3 to the Undefined, thus aborting the store in (4a), and causing the
condition in ICC3 to remain with the Z flag set, thus causing step (5) to loop back to step (1).
This algorithm suffers from two problems:
(1) The condition CCCR.CC3 is cleared unconditionally by an exception, irrespective of whether or
not any changes were made to the target memory location during that exception.
(2) The branch from step (5) back to step (1) may have to happen more than once until the store
manages to take place. In theory, this loop could cycle forever because there are too many
interrupts coming in, but it's unlikely.
=======
EXAMPLE
=======
Taking an example from include/asm-frv/atomic.h:
static inline int atomic_add_return(int i, atomic_t *v)
{
unsigned long val;
asm("0: \n"
It starts by setting ICC3.Z to true for later use, and also transforming that into CC3 being in the
True state.
" orcc gr0,gr0,gr0,icc3 \n" <-- (1)
" ckeq icc3,cc7 \n" <-- (1)
Then it does the load. Note that the final phase of step (1) is done at the same time as the
load. The VLIW packing ensures they are done simultaneously. The ".p" on the load must not be
removed without swapping the order of these two instructions.
" ld.p %M0,%1 \n" <-- (2)
" orcr cc7,cc7,cc3 \n" <-- (1)
Then the proposed modification is generated. Note that the old value can be retained if required
(such as in test_and_set_bit()).
" add%I2 %1,%2,%1 \n" <-- (3)
Then it attempts to store the value back, contingent on no exception having cleared CC3 since it
was set to True.
" cst.p %1,%M0 ,cc3,#1 \n" <-- (4a)
It simultaneously records the success or failure of the store in ICC3.Z.
" corcc gr29,gr29,gr0 ,cc3,#1 \n" <-- (4b)
Such that the branch can then be taken if the operation was aborted.
" beq icc3,#0,0b \n" <-- (5)
: "+U"(v->counter), "=&r"(val)
: "NPr"(i)
: "memory", "cc7", "cc3", "icc3"
);
return val;
}
=============
CONFIGURATION
=============
The atomic ops implementation can be made inline or out-of-line by changing the
CONFIG_FRV_OUTOFLINE_ATOMIC_OPS configuration variable. Making it out-of-line has a number of
advantages:
- The resulting kernel image may be smaller
- Debugging is easier as atomic ops can just be stepped over and they can be breakpointed
Keeping it inline also has a number of advantages:
- The resulting kernel may be Faster
- no out-of-line function calls need to be made
- the compiler doesn't have half its registers clobbered by making a call
The out-of-line implementations live in arch/frv/lib/atomic-ops.S.
=========================
BOOTING FR-V LINUX KERNEL
=========================
======================
PROVIDING A FILESYSTEM
======================
First of all, a root filesystem must be made available. This can be done in
one of two ways:
(1) NFS Export
A filesystem should be constructed in a directory on an NFS server that
the target board can reach. This directory should then be NFS exported
such that the target board can read and write into it as root.
(2) Flash Filesystem (JFFS2 Recommended)
In this case, the image must be stored or built up on flash before it
can be used. A complete image can be built using the mkfs.jffs2 or
similar program and then downloaded and stored into flash by RedBoot.
========================
LOADING THE KERNEL IMAGE
========================
The kernel will need to be loaded into RAM by RedBoot (or by some alternative
boot loader) before it can be run. The kernel image (arch/frv/boot/Image) may
be loaded in one of three ways:
(1) Load from Flash
This is the simplest. RedBoot can store an image in the flash (see the
RedBoot documentation) and then load it back into RAM. RedBoot keeps
track of the load address, entry point and size, so the command to do
this is simply:
fis load linux
The image is then ready to be executed.
(2) Load by TFTP
The following command will download a raw binary kernel image from the
default server (as negotiated by BOOTP) and store it into RAM:
load -b 0x00100000 -r /tftpboot/image.bin
The image is then ready to be executed.
(3) Load by Y-Modem
The following command will download a raw binary kernel image across the
serial port that RedBoot is currently using:
load -m ymodem -b 0x00100000 -r zImage
The serial client (such as minicom) must then be told to transmit the
program by Y-Modem.
When finished, the image will then be ready to be executed.
==================
BOOTING THE KERNEL
==================
Boot the image with the following RedBoot command:
exec -c "<CMDLINE>" 0x00100000
For example:
exec -c "console=ttySM0,115200 ip=:::::dhcp root=/dev/mtdblock2 rw"
This will start the kernel running. Note that if the GDB-stub is compiled in,
then the kernel will immediately wait for GDB to connect over serial before
doing anything else. See the section on kernel debugging with GDB.
The kernel command line <CMDLINE> tells the kernel where its console is and
how to find its root filesystem. This is made up of the following components,
separated by spaces:
(*) console=ttyS<x>[,<baud>[<parity>[<bits>[<flow>]]]]
This specifies that the system console should output through on-chip
serial port <x> (which can be "0" or "1").
<baud> is a standard baud rate between 1200 and 115200 (default 9600).
<parity> is a parity setting of "N", "O", "E", "M" or "S" for None, Odd,
Even, Mark or Space. "None" is the default.
<stop> is "7" or "8" for the number of bits per character. "8" is the
default.
<flow> is "r" to use flow control (XCTS on serial port 2 only). The
default is to not use flow control.
For example:
console=ttyS0,115200
To use the first on-chip serial port at baud rate 115200, no parity, 8
bits, and no flow control.
(*) root=<xxxx>
This specifies the device upon which the root filesystem resides. It
may be specified by major and minor number, device path, or even
partition uuid, if supported. For example:
/dev/nfs NFS root filesystem
/dev/mtdblock3 Fourth RedBoot partition on the System Flash
PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF/PARTNROFF=1
first partition after the partition with the given UUID
253:0 Device with major 253 and minor 0
Authoritative information can be found in
"Documentation/admin-guide/kernel-parameters.rst".
(*) rw
Start with the root filesystem mounted Read/Write.
The remaining components are all optional:
(*) ip=<ip>::::<host>:<iface>:<cfg>
Configure the network interface. If <cfg> is "off" then <ip> should
specify the IP address for the network device <iface>. <host> provide
the hostname for the device.
If <cfg> is "bootp" or "dhcp", then all of these parameters will be
discovered by consulting a BOOTP or DHCP server.
For example, the following might be used:
ip=192.168.73.12::::frv:eth0:off
This sets the IP address on the VDK motherboard RTL8029 ethernet chipset
(eth0) to be 192.168.73.12, and sets the board's hostname to be "frv".
(*) nfsroot=<server>:<dir>[,v<vers>]
This is mandatory if "root=/dev/nfs" is given as an option. It tells the
kernel the IP address of the NFS server providing its root filesystem,
and the pathname on that server of the filesystem.
The NFS version to use can also be specified. v2 and v3 are supported by
Linux.
For example:
nfsroot=192.168.73.1:/nfsroot-frv
(*) profile=1
Turns on the kernel profiler (accessible through /proc/profile).
(*) console=gdb0
This can be used as an alternative to the "console=ttyS..." listed
above. I tells the kernel to pass the console output to GDB if the
gdbstub is compiled in to the kernel.
If this is used, then the gdbstub passes the text to GDB, which then
simply dumps it to its standard output.
(*) mem=<xxx>M
Normally the kernel will work out how much SDRAM it has by reading the
SDRAM controller registers. That can be overridden with this
option. This allows the kernel to be told that it has <xxx> megabytes of
memory available.
(*) init=<prog> [<arg> [<arg> [<arg> ...]]]
This tells the kernel what program to run initially. By default this is
/sbin/init, but /sbin/sash or /bin/sh are common alternatives.
Clock scaling
-------------
The kernel supports scaling of CLCK.CMODE, CLCK.CM and CLKC.P0 clock
registers. If built with CONFIG_PM and CONFIG_SYSCTL options enabled, four
extra files will appear in the directory /proc/sys/pm/. Reading these files
will show:
p0 -- current value of the P0 bit in CLKC register.
cm -- current value of the CM bits in CLKC register.
cmode -- current value of the CMODE bits in CLKC register.
On all boards, the 'p0' file should also be writable, and either '1' or '0'
can be rewritten, to set or clear the CLKC_P0 bit respectively, hence
controlling whether the resource bus rate clock is halved.
The 'cm' file should also be available on all boards. '0' can be written to it
to shift the board into High-Speed mode (normal), and '1' can be written to
shift the board into Medium-Speed mode. Selecting Low-Speed mode is not
supported by this interface, even though some CPUs do support it.
On the boards with FR405 CPU (i.e. CB60 and CB70), the 'cmode' file is also
writable, allowing the CPU core speed (and other clock speeds) to be
controlled from userspace.
Determining current and possible settings
-----------------------------------------
The current state and the available masks can be found in /proc/cpuinfo. For
example, on the CB70:
# cat /proc/cpuinfo
CPU-Series: fr400
CPU-Core: fr405, gr0-31, BE, CCCR
CPU: mb93405
MMU: Prot
FP-Media: fr0-31, Media
System: mb93091-cb70, mb93090-mb00
PM-Controls: cmode=0xd31f, cm=0x3, p0=0x3, suspend=0x9
PM-Status: cmode=3, cm=0, p0=0
Clock-In: 50.00 MHz
Clock-Core: 300.00 MHz
Clock-SDRAM: 100.00 MHz
Clock-CBus: 100.00 MHz
Clock-Res: 50.00 MHz
Clock-Ext: 50.00 MHz
Clock-DSU: 25.00 MHz
BogoMips: 300.00
And on the PDK, the PM lines look like the following:
PM-Controls: cm=0x3, p0=0x3, suspend=0x9
PM-Status: cmode=9, cm=0, p0=0
The PM-Controls line, if present, will indicate which /proc/sys/pm files can
be set to what values. The specification values are bitmasks; so, for example,
"suspend=0x9" indicates that 0 and 3 can be written validly to
/proc/sys/pm/suspend.
The PM-Controls line will only be present if CONFIG_PM is configured to Y.
The PM-Status line indicates which clock controls are set to which value. If
the file can be read, then the suspend value must be 0, and so that's not
included.
=======================================
FUJITSU FR-V LINUX KERNEL CONFIGURATION
=======================================
=====================
CONFIGURATION OPTIONS
=====================
The most important setting is in the "MMU support options" tab (the first
presented in the configuration tools available):
(*) "Kernel Type"
This options allows selection of normal, MMU-requiring linux, and uClinux
(which doesn't require an MMU and doesn't have inter-process protection).
There are a number of settings in the "Processor type and features" section of
the kernel configuration that need to be considered.
(*) "CPU"
The register and instruction sets at the core of the processor. This can
only be set to "FR40x/45x/55x" at the moment - but this permits usage of
the kernel with MB93091 CB10, CB11, CB30, CB41, CB60, CB70 and CB451
CPU boards, and with the MB93093 PDK board.
(*) "System"
This option allows a choice of basic system. This governs the peripherals
that are expected to be available.
(*) "Motherboard"
This specifies the type of motherboard being used, and the peripherals
upon it. Currently only "MB93090-MB00" can be set here.
(*) "Default cache-write mode"
This controls the initial data cache write management mode. By default
Write-Through is selected, but Write-Back (Copy-Back) can also be
selected. This can be changed dynamically once the kernel is running (see
features.txt).
There are some architecture specific configuration options in the "General
Setup" section of the kernel configuration too:
(*) "Reserve memory uncached for (PCI) DMA"
This requests that a uClinux kernel set aside some memory in an uncached
window for the use as consistent DMA memory (mainly for PCI). At least a
megabyte will be allocated in this way, possibly more. Any memory so
reserved will not be available for normal allocations.
(*) "Kernel support for ELF-FDPIC binaries"
This enables the binary-format driver for the new FDPIC ELF binaries that
this platform normally uses. These binaries are totally relocatable -
their separate sections can relocated independently, allowing them to be
shared on uClinux where possible. This should normally be enabled.
(*) "Kernel image protection"
This makes the protection register governing access to the core kernel
image prohibit access by userspace programs. This option is available on
uClinux only.
There are also a number of settings in the "Kernel Hacking" section of the
kernel configuration especially for debugging a kernel on this
architecture. See the "gdbstub.txt" file for information about those.
======================
DEFAULT CONFIGURATIONS
======================
The kernel sources include a number of example default configurations:
(*) defconfig-mb93091
Default configuration for the MB93091-VDK with both CPU board and
MB93090-MB00 motherboard running uClinux.
(*) defconfig-mb93091-fb
Default configuration for the MB93091-VDK with CPU board,
MB93090-MB00 motherboard, and DAV board running uClinux.
Includes framebuffer driver.
(*) defconfig-mb93093
Default configuration for the MB93093-PDK board running uClinux.
(*) defconfig-cb70-standalone
Default configuration for the MB93091-VDK with only CB70 CPU board
running uClinux. This will use the CB70's DM9000 for network access.
(*) defconfig-mmu
Default configuration for the MB93091-VDK with both CB451 CPU board and
MB93090-MB00 motherboard running MMU linux.
(*) defconfig-mmu-audio
Default configuration for the MB93091-VDK with CB451 CPU board, DAV
board, and MB93090-MB00 motherboard running MMU linux. Includes
audio driver.
(*) defconfig-mmu-fb
Default configuration for the MB93091-VDK with CB451 CPU board, DAV
board, and MB93090-MB00 motherboard running MMU linux. Includes
framebuffer driver.
(*) defconfig-mmu-standalone
Default configuration for the MB93091-VDK with only CB451 CPU board
running MMU linux.
===========================
FUJITSU FR-V LINUX FEATURES
===========================
This kernel port has a number of features of which the user should be aware:
(*) Linux and uClinux
The FR-V architecture port supports both normal MMU linux and uClinux out
of the same sources.
(*) CPU support
Support for the FR401, FR403, FR405, FR451 and FR555 CPUs should work with
the same uClinux kernel configuration.
In normal (MMU) Linux mode, only the FR451 CPU will work as that is the
only one with a suitably featured CPU.
The kernel is written and compiled with the assumption that only the
bottom 32 GR registers and no FR registers will be used by the kernel
itself, however all extra userspace registers will be saved on context
switch. Note that since most CPUs can't support lazy switching, no attempt
is made to do lazy register saving where that would be possible (FR555
only currently).
(*) Board support
The board on which the kernel will run can be configured on the "Processor
type and features" configuration tab.
Set the System to "MB93093-PDK" to boot from the MB93093 (FR403) PDK.
Set the System to "MB93091-VDK" to boot from the CB11, CB30, CB41, CB60,
CB70 or CB451 VDK boards. Set the Motherboard setting to "MB93090-MB00" to
boot with the standard ATA90590B VDK motherboard, and set it to "None" to
boot without any motherboard.
(*) Binary Formats
The only userspace binary format supported is FDPIC ELF. Normal ELF, FLAT
and AOUT binaries are not supported for this architecture.
FDPIC ELF supports shared library and program interpreter facilities.
(*) Scheduler Speed
The kernel scheduler runs at 100Hz irrespective of the clock speed on this
architecture. This value is set in asm/param.h (see the HZ macro defined
there).
(*) Normal (MMU) Linux Memory Layout.
See mmu-layout.txt in this directory for a description of the normal linux
memory layout
See include/asm-frv/mem-layout.h for constants pertaining to the memory
layout.
See include/asm-frv/mb-regs.h for the constants pertaining to the I/O bus
controller configuration.
(*) uClinux Memory Layout
The memory layout used by the uClinux kernel is as follows:
0x00000000 - 0x00000FFF Null pointer catch page
0x20000000 - 0x200FFFFF CS2# [PDK] FPGA
0xC0000000 - 0xCFFFFFFF SDRAM
0xC0000000 Base of Linux kernel image
0xE0000000 - 0xEFFFFFFF CS2# [VDK] SLBUS/PCI window
0xF0000000 - 0xF0FFFFFF CS5# MB93493 CSC area (DAV daughter board)
0xF1000000 - 0xF1FFFFFF CS7# [CB70/CB451] CPU-card PCMCIA port space
0xFC000000 - 0xFC0FFFFF CS1# [VDK] MB86943 config space
0xFC100000 - 0xFC1FFFFF CS6# [CB70/CB451] CPU-card DM9000 NIC space
0xFC100000 - 0xFC1FFFFF CS6# [PDK] AX88796 NIC space
0xFC200000 - 0xFC2FFFFF CS3# MB93493 CSR area (DAV daughter board)
0xFD000000 - 0xFDFFFFFF CS4# [CB70/CB451] CPU-card extra flash space
0xFE000000 - 0xFEFFFFFF Internal CPU peripherals
0xFF000000 - 0xFF1FFFFF CS0# Flash 1
0xFF200000 - 0xFF3FFFFF CS0# Flash 2
0xFFC00000 - 0xFFC0001F CS0# [VDK] FPGA
The kernel reads the size of the SDRAM from the memory bus controller
registers by default.
The kernel initialisation code (1) adjusts the SDRAM base addresses to
move the SDRAM to desired address, (2) moves the kernel image down to the
bottom of SDRAM, (3) adjusts the bus controller registers to move I/O
windows, and (4) rearranges the protection registers to protect all of
this.
The reasons for doing this are: (1) the page at address 0 should be
inaccessible so that NULL pointer errors can be caught; and (2) the bottom
three quarters are left unoccupied so that an FR-V CPU with an MMU can use
it for virtual userspace mappings.
See include/asm-frv/mem-layout.h for constants pertaining to the memory
layout.
See include/asm-frv/mb-regs.h for the constants pertaining to the I/O bus
controller configuration.
(*) uClinux Memory Protection
A DAMPR register is used to cover the entire region used for I/O
(0xE0000000 - 0xFFFFFFFF). This permits the kernel to make uncached
accesses to this region. Userspace is not permitted to access it.
The DAMPR/IAMPR protection registers not in use for any other purpose are
tiled over the top of the SDRAM such that:
(1) The core kernel image is covered by as small a tile as possible
granting only the kernel access to the underlying data, whilst
making sure no SDRAM is actually made unavailable by this approach.
(2) All other tiles are arranged to permit userspace access to the rest
of the SDRAM.
Barring point (1), there is nothing to protect kernel data against
userspace damage - but this is uClinux.
(*) Exceptions and Fixups
Since the FR40x and FR55x CPUs that do not have full MMUs generate
imprecise data error exceptions, there are currently no automatic fixup
services available in uClinux. This includes misaligned memory access
fixups.
Userspace EFAULT errors can be trapped by issuing a MEMBAR instruction and
forcing the fault to happen there.
On the FR451, however, data exceptions are mostly precise, and so
exception fixup handling is implemented as normal.
(*) Userspace Breakpoints
The ptrace() system call supports the following userspace debugging
features:
(1) Hardware assisted single step.
(2) Breakpoint via the FR-V "BREAK" instruction.
(3) Breakpoint via the FR-V "TIRA GR0, #1" instruction.
(4) Syscall entry/exit trap.
Each of the above generates a SIGTRAP.
(*) On-Chip Serial Ports
The FR-V on-chip serial ports are made available as ttyS0 and ttyS1. Note
that if the GDB stub is compiled in, ttyS1 will not actually be available
as it will be being used for the GDB stub.
These ports can be made by:
mknod /dev/ttyS0 c 4 64
mknod /dev/ttyS1 c 4 65
(*) Maskable Interrupts
Level 15 (Non-maskable) interrupts are dealt with by the GDB stub if
present, and cause a panic if not. If the GDB stub is present, ttyS1's
interrupts are rated at level 15.
All other interrupts are distributed over the set of available priorities
so that no IRQs are shared where possible. The arch interrupt handling
routines attempt to disentangle the various sources available through the
CPU's own multiplexor, and those on off-CPU peripherals.
(*) Accessing PCI Devices
Where PCI is available, care must be taken when dealing with drivers that
access PCI devices. PCI devices present their data in little-endian form,
but the CPU sees it in big-endian form. The macros in asm/io.h try to get
this right, but may not under all circumstances...
(*) Ax88796 Ethernet Driver
The MB93093 PDK board has an Ax88796 ethernet chipset (an NE2000 clone). A
driver has been written to deal specifically with this. The driver
provides MII services for the card.
The driver can be configured by running make xconfig, and going to:
(*) Network device support
- turn on "Network device support"
(*) Ethernet (10 or 100Mbit)
- turn on "Ethernet (10 or 100Mbit)"
- turn on "AX88796 NE2000 compatible chipset"
The driver can be found in:
drivers/net/ax88796.c
include/asm/ax88796.h
(*) WorkRAM Driver
This driver provides a character device that permits access to the WorkRAM
that can be found on the FR451 CPU. Each page is accessible through a
separate minor number, thereby permitting each page to have its own
filesystem permissions set on the device file.
The device files should be:
mknod /dev/frv/workram0 c 240 0
mknod /dev/frv/workram1 c 240 1
mknod /dev/frv/workram2 c 240 2
...
The driver will not permit the opening of any device file that does not
correspond to at least a partial page of WorkRAM. So the first device file
is the only one available on the FR451. If any other CPU is detected, none
of the devices will be openable.
The devices can be accessed with read, write and llseek, and can also be
mmapped. If they're mmapped, they will only map at the appropriate
0x7e8nnnnn address on linux and at the 0xfe8nnnnn address on uClinux. If
MAP_FIXED is not specified, the appropriate address will be chosen anyway.
The mappings must be MAP_SHARED not MAP_PRIVATE, and must not be
PROT_EXEC. They must also start at file offset 0, and must not be longer
than one page in size.
This driver can be configured by running make xconfig, and going to:
(*) Character devices
- turn on "Fujitsu FR-V CPU WorkRAM support"
(*) Dynamic data cache write mode changing
It is possible to view and to change the data cache's write mode through
the /proc/sys/frv/cache-mode file while the kernel is running. There are
two modes available:
NAME MEANING
===== ==========================================
wthru Data cache is in Write-Through mode
wback Data cache is in Write-Back/Copy-Back mode
To read the cache mode:
# cat /proc/sys/frv/cache-mode
wthru
To change the cache mode:
# echo wback >/proc/sys/frv/cache-mode
# cat /proc/sys/frv/cache-mode
wback
(*) MMU Context IDs and Pinning
On MMU Linux the CPU supports the concept of a context ID in its MMU to
make it more efficient (TLB entries are labelled with a context ID to link
them to specific tasks).
Normally once a context ID is allocated, it will remain affixed to a task
or CLONE_VM'd group of tasks for as long as it exists. However, since the
kernel is capable of supporting more tasks than there are possible ID
numbers, the kernel will pass context IDs from one task to another if
there are insufficient available.
The context ID currently in use by a task can be viewed in /proc:
# grep CXNR /proc/1/status
CXNR: 1
Note that kernel threads do not have a userspace context, and so will not
show a CXNR entry in that file.
Under some circumstances, however, it is desirable to pin a context ID on
a process such that the kernel won't pass it on. This can be done by
writing the process ID of the target process to a special file:
# echo 17 >/proc/sys/frv/pin-cxnr
Reading from the file will then show the context ID pinned.
# cat /proc/sys/frv/pin-cxnr
4
The context ID will remain pinned as long as any process is using that
context, i.e.: when the all the subscribing processes have exited or
exec'd; or when an unpinning request happens:
# echo 0 >/proc/sys/frv/pin-cxnr
When there isn't a pinned context, the file shows -1:
# cat /proc/sys/frv/pin-cxnr
-1
set remotebreak 1
define _amr
printf "AMRx DAMR IAMR \n"
printf "==== ===================== =====================\n"
printf "amr0 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x0].L,__debug_mmu.damr[0x0].P,__debug_mmu.iamr[0x0].L,__debug_mmu.iamr[0x0].P
printf "amr1 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x1].L,__debug_mmu.damr[0x1].P,__debug_mmu.iamr[0x1].L,__debug_mmu.iamr[0x1].P
printf "amr2 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x2].L,__debug_mmu.damr[0x2].P,__debug_mmu.iamr[0x2].L,__debug_mmu.iamr[0x2].P
printf "amr3 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x3].L,__debug_mmu.damr[0x3].P,__debug_mmu.iamr[0x3].L,__debug_mmu.iamr[0x3].P
printf "amr4 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x4].L,__debug_mmu.damr[0x4].P,__debug_mmu.iamr[0x4].L,__debug_mmu.iamr[0x4].P
printf "amr5 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x5].L,__debug_mmu.damr[0x5].P,__debug_mmu.iamr[0x5].L,__debug_mmu.iamr[0x5].P
printf "amr6 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x6].L,__debug_mmu.damr[0x6].P,__debug_mmu.iamr[0x6].L,__debug_mmu.iamr[0x6].P
printf "amr7 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x7].L,__debug_mmu.damr[0x7].P,__debug_mmu.iamr[0x7].L,__debug_mmu.iamr[0x7].P
printf "amr8 : L:%08lx P:%08lx\n",__debug_mmu.damr[0x8].L,__debug_mmu.damr[0x8].P
printf "amr9 : L:%08lx P:%08lx\n",__debug_mmu.damr[0x9].L,__debug_mmu.damr[0x9].P
printf "amr10: L:%08lx P:%08lx\n",__debug_mmu.damr[0xa].L,__debug_mmu.damr[0xa].P
printf "amr11: L:%08lx P:%08lx\n",__debug_mmu.damr[0xb].L,__debug_mmu.damr[0xb].P
end
define _tlb
printf "tlb[0x00]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x0].L,__debug_mmu.tlb[0x0].P,__debug_mmu.tlb[0x40+0x0].L,__debug_mmu.tlb[0x40+0x0].P
printf "tlb[0x01]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1].L,__debug_mmu.tlb[0x1].P,__debug_mmu.tlb[0x40+0x1].L,__debug_mmu.tlb[0x40+0x1].P
printf "tlb[0x02]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2].L,__debug_mmu.tlb[0x2].P,__debug_mmu.tlb[0x40+0x2].L,__debug_mmu.tlb[0x40+0x2].P
printf "tlb[0x03]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3].L,__debug_mmu.tlb[0x3].P,__debug_mmu.tlb[0x40+0x3].L,__debug_mmu.tlb[0x40+0x3].P
printf "tlb[0x04]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x4].L,__debug_mmu.tlb[0x4].P,__debug_mmu.tlb[0x40+0x4].L,__debug_mmu.tlb[0x40+0x4].P
printf "tlb[0x05]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x5].L,__debug_mmu.tlb[0x5].P,__debug_mmu.tlb[0x40+0x5].L,__debug_mmu.tlb[0x40+0x5].P
printf "tlb[0x06]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x6].L,__debug_mmu.tlb[0x6].P,__debug_mmu.tlb[0x40+0x6].L,__debug_mmu.tlb[0x40+0x6].P
printf "tlb[0x07]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x7].L,__debug_mmu.tlb[0x7].P,__debug_mmu.tlb[0x40+0x7].L,__debug_mmu.tlb[0x40+0x7].P
printf "tlb[0x08]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x8].L,__debug_mmu.tlb[0x8].P,__debug_mmu.tlb[0x40+0x8].L,__debug_mmu.tlb[0x40+0x8].P
printf "tlb[0x09]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x9].L,__debug_mmu.tlb[0x9].P,__debug_mmu.tlb[0x40+0x9].L,__debug_mmu.tlb[0x40+0x9].P
printf "tlb[0x0a]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xa].L,__debug_mmu.tlb[0xa].P,__debug_mmu.tlb[0x40+0xa].L,__debug_mmu.tlb[0x40+0xa].P
printf "tlb[0x0b]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xb].L,__debug_mmu.tlb[0xb].P,__debug_mmu.tlb[0x40+0xb].L,__debug_mmu.tlb[0x40+0xb].P
printf "tlb[0x0c]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xc].L,__debug_mmu.tlb[0xc].P,__debug_mmu.tlb[0x40+0xc].L,__debug_mmu.tlb[0x40+0xc].P
printf "tlb[0x0d]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xd].L,__debug_mmu.tlb[0xd].P,__debug_mmu.tlb[0x40+0xd].L,__debug_mmu.tlb[0x40+0xd].P
printf "tlb[0x0e]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xe].L,__debug_mmu.tlb[0xe].P,__debug_mmu.tlb[0x40+0xe].L,__debug_mmu.tlb[0x40+0xe].P
printf "tlb[0x0f]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xf].L,__debug_mmu.tlb[0xf].P,__debug_mmu.tlb[0x40+0xf].L,__debug_mmu.tlb[0x40+0xf].P
printf "tlb[0x10]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x10].L,__debug_mmu.tlb[0x10].P,__debug_mmu.tlb[0x40+0x10].L,__debug_mmu.tlb[0x40+0x10].P
printf "tlb[0x11]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x11].L,__debug_mmu.tlb[0x11].P,__debug_mmu.tlb[0x40+0x11].L,__debug_mmu.tlb[0x40+0x11].P
printf "tlb[0x12]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x12].L,__debug_mmu.tlb[0x12].P,__debug_mmu.tlb[0x40+0x12].L,__debug_mmu.tlb[0x40+0x12].P
printf "tlb[0x13]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x13].L,__debug_mmu.tlb[0x13].P,__debug_mmu.tlb[0x40+0x13].L,__debug_mmu.tlb[0x40+0x13].P
printf "tlb[0x14]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x14].L,__debug_mmu.tlb[0x14].P,__debug_mmu.tlb[0x40+0x14].L,__debug_mmu.tlb[0x40+0x14].P
printf "tlb[0x15]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x15].L,__debug_mmu.tlb[0x15].P,__debug_mmu.tlb[0x40+0x15].L,__debug_mmu.tlb[0x40+0x15].P
printf "tlb[0x16]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x16].L,__debug_mmu.tlb[0x16].P,__debug_mmu.tlb[0x40+0x16].L,__debug_mmu.tlb[0x40+0x16].P
printf "tlb[0x17]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x17].L,__debug_mmu.tlb[0x17].P,__debug_mmu.tlb[0x40+0x17].L,__debug_mmu.tlb[0x40+0x17].P
printf "tlb[0x18]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x18].L,__debug_mmu.tlb[0x18].P,__debug_mmu.tlb[0x40+0x18].L,__debug_mmu.tlb[0x40+0x18].P
printf "tlb[0x19]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x19].L,__debug_mmu.tlb[0x19].P,__debug_mmu.tlb[0x40+0x19].L,__debug_mmu.tlb[0x40+0x19].P
printf "tlb[0x1a]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1a].L,__debug_mmu.tlb[0x1a].P,__debug_mmu.tlb[0x40+0x1a].L,__debug_mmu.tlb[0x40+0x1a].P
printf "tlb[0x1b]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1b].L,__debug_mmu.tlb[0x1b].P,__debug_mmu.tlb[0x40+0x1b].L,__debug_mmu.tlb[0x40+0x1b].P
printf "tlb[0x1c]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1c].L,__debug_mmu.tlb[0x1c].P,__debug_mmu.tlb[0x40+0x1c].L,__debug_mmu.tlb[0x40+0x1c].P
printf "tlb[0x1d]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1d].L,__debug_mmu.tlb[0x1d].P,__debug_mmu.tlb[0x40+0x1d].L,__debug_mmu.tlb[0x40+0x1d].P
printf "tlb[0x1e]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1e].L,__debug_mmu.tlb[0x1e].P,__debug_mmu.tlb[0x40+0x1e].L,__debug_mmu.tlb[0x40+0x1e].P
printf "tlb[0x1f]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1f].L,__debug_mmu.tlb[0x1f].P,__debug_mmu.tlb[0x40+0x1f].L,__debug_mmu.tlb[0x40+0x1f].P
printf "tlb[0x20]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x20].L,__debug_mmu.tlb[0x20].P,__debug_mmu.tlb[0x40+0x20].L,__debug_mmu.tlb[0x40+0x20].P
printf "tlb[0x21]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x21].L,__debug_mmu.tlb[0x21].P,__debug_mmu.tlb[0x40+0x21].L,__debug_mmu.tlb[0x40+0x21].P
printf "tlb[0x22]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x22].L,__debug_mmu.tlb[0x22].P,__debug_mmu.tlb[0x40+0x22].L,__debug_mmu.tlb[0x40+0x22].P
printf "tlb[0x23]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x23].L,__debug_mmu.tlb[0x23].P,__debug_mmu.tlb[0x40+0x23].L,__debug_mmu.tlb[0x40+0x23].P
printf "tlb[0x24]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x24].L,__debug_mmu.tlb[0x24].P,__debug_mmu.tlb[0x40+0x24].L,__debug_mmu.tlb[0x40+0x24].P
printf "tlb[0x25]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x25].L,__debug_mmu.tlb[0x25].P,__debug_mmu.tlb[0x40+0x25].L,__debug_mmu.tlb[0x40+0x25].P
printf "tlb[0x26]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x26].L,__debug_mmu.tlb[0x26].P,__debug_mmu.tlb[0x40+0x26].L,__debug_mmu.tlb[0x40+0x26].P
printf "tlb[0x27]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x27].L,__debug_mmu.tlb[0x27].P,__debug_mmu.tlb[0x40+0x27].L,__debug_mmu.tlb[0x40+0x27].P
printf "tlb[0x28]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x28].L,__debug_mmu.tlb[0x28].P,__debug_mmu.tlb[0x40+0x28].L,__debug_mmu.tlb[0x40+0x28].P
printf "tlb[0x29]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x29].L,__debug_mmu.tlb[0x29].P,__debug_mmu.tlb[0x40+0x29].L,__debug_mmu.tlb[0x40+0x29].P
printf "tlb[0x2a]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2a].L,__debug_mmu.tlb[0x2a].P,__debug_mmu.tlb[0x40+0x2a].L,__debug_mmu.tlb[0x40+0x2a].P
printf "tlb[0x2b]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2b].L,__debug_mmu.tlb[0x2b].P,__debug_mmu.tlb[0x40+0x2b].L,__debug_mmu.tlb[0x40+0x2b].P
printf "tlb[0x2c]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2c].L,__debug_mmu.tlb[0x2c].P,__debug_mmu.tlb[0x40+0x2c].L,__debug_mmu.tlb[0x40+0x2c].P
printf "tlb[0x2d]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2d].L,__debug_mmu.tlb[0x2d].P,__debug_mmu.tlb[0x40+0x2d].L,__debug_mmu.tlb[0x40+0x2d].P
printf "tlb[0x2e]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2e].L,__debug_mmu.tlb[0x2e].P,__debug_mmu.tlb[0x40+0x2e].L,__debug_mmu.tlb[0x40+0x2e].P
printf "tlb[0x2f]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2f].L,__debug_mmu.tlb[0x2f].P,__debug_mmu.tlb[0x40+0x2f].L,__debug_mmu.tlb[0x40+0x2f].P
printf "tlb[0x30]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x30].L,__debug_mmu.tlb[0x30].P,__debug_mmu.tlb[0x40+0x30].L,__debug_mmu.tlb[0x40+0x30].P
printf "tlb[0x31]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x31].L,__debug_mmu.tlb[0x31].P,__debug_mmu.tlb[0x40+0x31].L,__debug_mmu.tlb[0x40+0x31].P
printf "tlb[0x32]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x32].L,__debug_mmu.tlb[0x32].P,__debug_mmu.tlb[0x40+0x32].L,__debug_mmu.tlb[0x40+0x32].P
printf "tlb[0x33]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x33].L,__debug_mmu.tlb[0x33].P,__debug_mmu.tlb[0x40+0x33].L,__debug_mmu.tlb[0x40+0x33].P
printf "tlb[0x34]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x34].L,__debug_mmu.tlb[0x34].P,__debug_mmu.tlb[0x40+0x34].L,__debug_mmu.tlb[0x40+0x34].P
printf "tlb[0x35]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x35].L,__debug_mmu.tlb[0x35].P,__debug_mmu.tlb[0x40+0x35].L,__debug_mmu.tlb[0x40+0x35].P
printf "tlb[0x36]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x36].L,__debug_mmu.tlb[0x36].P,__debug_mmu.tlb[0x40+0x36].L,__debug_mmu.tlb[0x40+0x36].P
printf "tlb[0x37]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x37].L,__debug_mmu.tlb[0x37].P,__debug_mmu.tlb[0x40+0x37].L,__debug_mmu.tlb[0x40+0x37].P
printf "tlb[0x38]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x38].L,__debug_mmu.tlb[0x38].P,__debug_mmu.tlb[0x40+0x38].L,__debug_mmu.tlb[0x40+0x38].P
printf "tlb[0x39]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x39].L,__debug_mmu.tlb[0x39].P,__debug_mmu.tlb[0x40+0x39].L,__debug_mmu.tlb[0x40+0x39].P
printf "tlb[0x3a]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3a].L,__debug_mmu.tlb[0x3a].P,__debug_mmu.tlb[0x40+0x3a].L,__debug_mmu.tlb[0x40+0x3a].P
printf "tlb[0x3b]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3b].L,__debug_mmu.tlb[0x3b].P,__debug_mmu.tlb[0x40+0x3b].L,__debug_mmu.tlb[0x40+0x3b].P
printf "tlb[0x3c]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3c].L,__debug_mmu.tlb[0x3c].P,__debug_mmu.tlb[0x40+0x3c].L,__debug_mmu.tlb[0x40+0x3c].P
printf "tlb[0x3d]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3d].L,__debug_mmu.tlb[0x3d].P,__debug_mmu.tlb[0x40+0x3d].L,__debug_mmu.tlb[0x40+0x3d].P
printf "tlb[0x3e]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3e].L,__debug_mmu.tlb[0x3e].P,__debug_mmu.tlb[0x40+0x3e].L,__debug_mmu.tlb[0x40+0x3e].P
printf "tlb[0x3f]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3f].L,__debug_mmu.tlb[0x3f].P,__debug_mmu.tlb[0x40+0x3f].L,__debug_mmu.tlb[0x40+0x3f].P
end
define _pgd
p (pgd_t[0x40])*(pgd_t*)(__debug_mmu.damr[0x3].L)
end
define _ptd_i
p (pte_t[0x1000])*(pte_t*)(__debug_mmu.damr[0x4].L)
end
define _ptd_d
p (pte_t[0x1000])*(pte_t*)(__debug_mmu.damr[0x5].L)
end
====================
DEBUGGING FR-V LINUX
====================
The kernel contains a GDB stub that talks GDB remote protocol across a serial
port. This permits GDB to single step through the kernel, set breakpoints and
trap exceptions that happen in kernel space and interrupt execution. It also
permits the NMI interrupt button or serial port events to jump the kernel into
the debugger.
On the CPUs that have on-chip UARTs (FR400, FR403, FR405, FR555), the
GDB stub hijacks a serial port for its own purposes, and makes it
generate level 15 interrupts (NMI). The kernel proper cannot see the serial
port in question under these conditions.
On the MB93091-VDK CPU boards, the GDB stub uses UART1, which would otherwise
be /dev/ttyS1. On the MB93093-PDK, the GDB stub uses UART0. Therefore, on the
PDK there is no externally accessible serial port and the serial port to
which the touch screen is attached becomes /dev/ttyS0.
Note that the GDB stub runs entirely within CPU debug mode, and so should not
incur any exceptions or interrupts whilst it is active. In particular, note
that the clock will lose time since it is implemented in software.
==================
KERNEL PREPARATION
==================
Firstly, a debuggable kernel must be built. To do this, unpack the kernel tree
and copy the configuration that you wish to use to .config. Then reconfigure
the following things on the "Kernel Hacking" tab:
(*) "Include debugging information"
Set this to "Y". This causes all C and Assembly files to be compiled
to include debugging information.
(*) "In-kernel GDB stub"
Set this to "Y". This causes the GDB stub to be compiled into the
kernel.
(*) "Immediate activation"
Set this to "Y" if you want the GDB stub to activate as soon as possible
and wait for GDB to connect. This allows you to start tracing right from
the beginning of start_kernel() in init/main.c.
(*) "Console through GDB stub"
Set this to "Y" if you wish to be able to use "console=gdb0" on the
command line. That tells the kernel to pass system console messages to
GDB (which then prints them on its standard output). This is useful when
debugging the serial drivers that'd otherwise be used to pass console
messages to the outside world.
Then build as usual, download to the board and execute. Note that if
"Immediate activation" was selected, then the kernel will wait for GDB to
attach. If not, then the kernel will boot immediately and GDB will have to
interrupt it or wait for an exception to occur before doing anything with
the kernel.
=========================
KERNEL DEBUGGING WITH GDB
=========================
Set the serial port on the computer that's going to run GDB to the appropriate
baud rate. Assuming the board's debug port is connected to ttyS0/COM1 on the
computer doing the debugging:
stty -F /dev/ttyS0 115200
Then start GDB in the base of the kernel tree:
frv-uclinux-gdb linux [uClinux]
Or:
frv-uclinux-gdb vmlinux [MMU linux]
When the prompt appears:
GNU gdb frv-031024
Copyright 2003 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "--host=i686-pc-linux-gnu --target=frv-uclinux"...
(gdb)
Attach to the board like this:
(gdb) target remote /dev/ttyS0
Remote debugging using /dev/ttyS0
start_kernel () at init/main.c:395
(gdb)
This should show the appropriate lines from the source too. The kernel can
then be debugged almost as if it's any other program.
===============================
INTERRUPTING THE RUNNING KERNEL
===============================
The kernel can be interrupted whilst it is running, causing a jump back to the
GDB stub and the debugger:
(*) Pressing Ctrl-C in GDB. This will cause GDB to try and interrupt the
kernel by sending an RS232 BREAK over the serial line to the GDB
stub. This will (mostly) immediately interrupt the kernel and return it
to the debugger.
(*) Pressing the NMI button on the board will also cause a jump into the
debugger.
(*) Setting a software breakpoint. This sets a break instruction at the
desired location which the GDB stub then traps the exception for.
(*) Setting a hardware breakpoint. The GDB stub is capable of using the IBAR
and DBAR registers to assist debugging.
Furthermore, the GDB stub will intercept a number of exceptions automatically
if they are caused by kernel execution. It will also intercept BUG() macro
invocation.
=================================
INTERNAL KERNEL ABI FOR FR-V ARCH
=================================
The internal FRV kernel ABI is not quite the same as the userspace ABI. A
number of the registers are used for special purposed, and the ABI is not
consistent between modules vs core, and MMU vs no-MMU.
This partly stems from the fact that FRV CPUs do not have a separate
supervisor stack pointer, and most of them do not have any scratch
registers, thus requiring at least one general purpose register to be
clobbered in such an event. Also, within the kernel core, it is possible to
simply jump or call directly between functions using a relative offset.
This cannot be extended to modules for the displacement is likely to be too
far. Thus in modules the address of a function to call must be calculated
in a register and then used, requiring two extra instructions.
This document has the following sections:
(*) System call register ABI
(*) CPU operating modes
(*) Internal kernel-mode register ABI
(*) Internal debug-mode register ABI
(*) Virtual interrupt handling
========================
SYSTEM CALL REGISTER ABI
========================
When a system call is made, the following registers are effective:
REGISTERS CALL RETURN
=============== ======================= =======================
GR7 System call number Preserved
GR8 Syscall arg #1 Return value
GR9-GR13 Syscall arg #2-6 Preserved
===================
CPU OPERATING MODES
===================
The FR-V CPU has three basic operating modes. In order of increasing
capability:
(1) User mode.
Basic userspace running mode.
(2) Kernel mode.
Normal kernel mode. There are many additional control registers
available that may be accessed in this mode, in addition to all the
stuff available to user mode. This has two submodes:
(a) Exceptions enabled (PSR.T == 1).
Exceptions will invoke the appropriate normal kernel mode
handler. On entry to the handler, the PSR.T bit will be cleared.
(b) Exceptions disabled (PSR.T == 0).
No exceptions or interrupts may happen. Any mandatory exceptions
will cause the CPU to halt unless the CPU is told to jump into
debug mode instead.
(3) Debug mode.
No exceptions may happen in this mode. Memory protection and
management exceptions will be flagged for later consideration, but
the exception handler won't be invoked. Debugging traps such as
hardware breakpoints and watchpoints will be ignored. This mode is
entered only by debugging events obtained from the other two modes.
All kernel mode registers may be accessed, plus a few extra debugging
specific registers.
=================================
INTERNAL KERNEL-MODE REGISTER ABI
=================================
There are a number of permanent register assignments that are set up by
entry.S in the exception prologue. Note that there is a complete set of
exception prologues for each of user->kernel transition and kernel->kernel
transition. There are also user->debug and kernel->debug mode transition
prologues.
REGISTER FLAVOUR USE
=============== ======= ==============================================
GR1 Supervisor stack pointer
GR15 Current thread info pointer
GR16 GP-Rel base register for small data
GR28 Current exception frame pointer (__frame)
GR29 Current task pointer (current)
GR30 Destroyed by kernel mode entry
GR31 NOMMU Destroyed by debug mode entry
GR31 MMU Destroyed by TLB miss kernel mode entry
CCR.ICC2 Virtual interrupt disablement tracking
CCCR.CC3 Cleared by exception prologue
(atomic op emulation)
SCR0 MMU See mmu-layout.txt.
SCR1 MMU See mmu-layout.txt.
SCR2 MMU Save for EAR0 (destroyed by icache insns
in debug mode)
SCR3 MMU Save for GR31 during debug exceptions
DAMR/IAMR NOMMU Fixed memory protection layout.
DAMR/IAMR MMU See mmu-layout.txt.
Certain registers are also used or modified across function calls:
REGISTER CALL RETURN
=============== =============================== ======================
GR0 Fixed Zero -
GR2 Function call frame pointer
GR3 Special Preserved
GR3-GR7 - Clobbered
GR8 Function call arg #1 Return value
(or clobbered)
GR9 Function call arg #2 Return value MSW
(or clobbered)
GR10-GR13 Function call arg #3-#6 Clobbered
GR14 - Clobbered
GR15-GR16 Special Preserved
GR17-GR27 - Preserved
GR28-GR31 Special Only accessed
explicitly
LR Return address after CALL Clobbered
CCR/CCCR - Mostly Clobbered
================================
INTERNAL DEBUG-MODE REGISTER ABI
================================
This is the same as the kernel-mode register ABI for functions calls. The
difference is that in debug-mode there's a different stack and a different
exception frame. Almost all the global registers from kernel-mode
(including the stack pointer) may be changed.
REGISTER FLAVOUR USE
=============== ======= ==============================================
GR1 Debug stack pointer
GR16 GP-Rel base register for small data
GR31 Current debug exception frame pointer
(__debug_frame)
SCR3 MMU Saved value of GR31
Note that debug mode is able to interfere with the kernel's emulated atomic
ops, so it must be exceedingly careful not to do any that would interact
with the main kernel in this regard. Hence the debug mode code (gdbstub) is
almost completely self-contained. The only external code used is the
sprintf family of functions.
Furthermore, break.S is so complicated because single-step mode does not
switch off on entry to an exception. That means unless manually disabled,
single-stepping will blithely go on stepping into things like interrupts.
See gdbstub.txt for more information.
==========================
VIRTUAL INTERRUPT HANDLING
==========================
Because accesses to the PSR is so slow, and to disable interrupts we have
to access it twice (once to read and once to write), we don't actually
disable interrupts at all if we don't have to. What we do instead is use
the ICC2 condition code flags to note virtual disablement, such that if we
then do take an interrupt, we note the flag, really disable interrupts, set
another flag and resume execution at the point the interrupt happened.
Setting condition flags as a side effect of an arithmetic or logical
instruction is really fast. This use of the ICC2 only occurs within the
kernel - it does not affect userspace.
The flags we use are:
(*) CCR.ICC2.Z [Zero flag]
Set to virtually disable interrupts, clear when interrupts are
virtually enabled. Can be modified by logical instructions without
affecting the Carry flag.
(*) CCR.ICC2.C [Carry flag]
Clear to indicate hardware interrupts are really disabled, set otherwise.
What happens is this:
(1) Normal kernel-mode operation.
ICC2.Z is 0, ICC2.C is 1.
(2) An interrupt occurs. The exception prologue examines ICC2.Z and
determines that nothing needs doing. This is done simply with an
unlikely BEQ instruction.
(3) The interrupts are disabled (local_irq_disable)
ICC2.Z is set to 1.
(4) If interrupts were then re-enabled (local_irq_enable):
ICC2.Z would be set to 0.
A TIHI #2 instruction (trap #2 if condition HI - Z==0 && C==0) would
be used to trap if interrupts were now virtually enabled, but
physically disabled - which they're not, so the trap isn't taken. The
kernel would then be back to state (1).
(5) An interrupt occurs. The exception prologue examines ICC2.Z and
determines that the interrupt shouldn't actually have happened. It
jumps aside, and there disabled interrupts by setting PSR.PIL to 14
and then it clears ICC2.C.
(6) If interrupts were then saved and disabled again (local_irq_save):
ICC2.Z would be shifted into the save variable and masked off
(giving a 1).
ICC2.Z would then be set to 1 (thus unchanged), and ICC2.C would be
unaffected (ie: 0).
(7) If interrupts were then restored from state (6) (local_irq_restore):
ICC2.Z would be set to indicate the result of XOR'ing the saved
value (ie: 1) with 1, which gives a result of 0 - thus leaving
ICC2.Z set.
ICC2.C would remain unaffected (ie: 0).
A TIHI #2 instruction would be used to again assay the current state,
but this would do nothing as Z==1.
(8) If interrupts were then enabled (local_irq_enable):
ICC2.Z would be cleared. ICC2.C would be left unaffected. Both
flags would now be 0.
A TIHI #2 instruction again issued to assay the current state would
then trap as both Z==0 [interrupts virtually enabled] and C==0
[interrupts really disabled] would then be true.
(9) The trap #2 handler would simply enable hardware interrupts
(set PSR.PIL to 0), set ICC2.C to 1 and return.
(10) Immediately upon returning, the pending interrupt would be taken.
(11) The interrupt handler would take the path of actually processing the
interrupt (ICC2.Z is clear, BEQ fails as per step (2)).
(12) The interrupt handler would then set ICC2.C to 1 since hardware
interrupts are definitely enabled - or else the kernel wouldn't be here.
(13) On return from the interrupt handler, things would be back to state (1).
This trap (#2) is only available in kernel mode. In user mode it will
result in SIGILL.
=================================
FR451 MMU LINUX MEMORY MANAGEMENT
=================================
============
MMU HARDWARE
============
FR451 MMU Linux puts the MMU into EDAT mode whilst running. This means that it uses both the SAT
registers and the DAT TLB to perform address translation.
There are 8 IAMLR/IAMPR register pairs and 16 DAMLR/DAMPR register pairs for SAT mode.
In DAT mode, there is also a TLB organised in cache format as 64 lines x 2 ways. Each line spans a
16KB range of addresses, but can match a larger region.
===========================
MEMORY MANAGEMENT REGISTERS
===========================
Certain control registers are used by the kernel memory management routines:
REGISTERS USAGE
====================== ==================================================
IAMR0, DAMR0 Kernel image and data mappings
IAMR1, DAMR1 First-chance TLB lookup mapping
DAMR2 Page attachment for cache flush by page
DAMR3 Current PGD mapping
SCR0, DAMR4 Instruction TLB PGE/PTD cache
SCR1, DAMR5 Data TLB PGE/PTD cache
DAMR6-10 kmap_atomic() mappings
DAMR11 I/O mapping
CXNR mm_struct context ID
TTBR Page directory (PGD) pointer (physical address)
=====================
GENERAL MEMORY LAYOUT
=====================
The physical memory layout is as follows:
PHYSICAL ADDRESS CONTROLLER DEVICE
=================== ============== =======================================
00000000 - BFFFFFFF SDRAM SDRAM area
E0000000 - EFFFFFFF L-BUS CS2# VDK SLBUS/PCI window
F0000000 - F0FFFFFF L-BUS CS5# MB93493 CSC area (DAV daughter board)
F1000000 - F1FFFFFF L-BUS CS7# (CB70 CPU-card PCMCIA port I/O space)
FC000000 - FC0FFFFF L-BUS CS1# VDK MB86943 config space
FC100000 - FC1FFFFF L-BUS CS6# DM9000 NIC I/O space
FC200000 - FC2FFFFF L-BUS CS3# MB93493 CSR area (DAV daughter board)
FD000000 - FDFFFFFF L-BUS CS4# (CB70 CPU-card extra flash space)
FE000000 - FEFFFFFF Internal CPU peripherals
FF000000 - FF1FFFFF L-BUS CS0# Flash 1
FF200000 - FF3FFFFF L-BUS CS0# Flash 2
FFC00000 - FFC0001F L-BUS CS0# FPGA
The virtual memory layout is:
VIRTUAL ADDRESS PHYSICAL TRANSLATOR FLAGS SIZE OCCUPATION
================= ======== ============== ======= ======= ===================================
00004000-BFFFFFFF various TLB,xAMR1 D-N-??V 3GB Userspace
C0000000-CFFFFFFF 00000000 xAMPR0 -L-S--V 256MB Kernel image and data
D0000000-D7FFFFFF various TLB,xAMR1 D-NS??V 128MB vmalloc area
D8000000-DBFFFFFF various TLB,xAMR1 D-NS??V 64MB kmap() area
DC000000-DCFFFFFF various TLB 1MB Secondary kmap_atomic() frame
DD000000-DD27FFFF various DAMR 160KB Primary kmap_atomic() frame
DD040000 DAMR2/IAMR2 -L-S--V page Page cache flush attachment point
DD080000 DAMR3 -L-SC-V page Page Directory (PGD)
DD0C0000 DAMR4 -L-SC-V page Cached insn TLB Page Table lookup
DD100000 DAMR5 -L-SC-V page Cached data TLB Page Table lookup
DD140000 DAMR6 -L-S--V page kmap_atomic(KM_BOUNCE_READ)
DD180000 DAMR7 -L-S--V page kmap_atomic(KM_SKB_SUNRPC_DATA)
DD1C0000 DAMR8 -L-S--V page kmap_atomic(KM_SKB_DATA_SOFTIRQ)
DD200000 DAMR9 -L-S--V page kmap_atomic(KM_USER0)
DD240000 DAMR10 -L-S--V page kmap_atomic(KM_USER1)
E0000000-FFFFFFFF E0000000 DAMR11 -L-SC-V 512MB I/O region
IAMPR1 and DAMPR1 are used as an extension to the TLB.
====================
KMAP AND KMAP_ATOMIC
====================
To access pages in the page cache (which may not be directly accessible if highmem is available),
the kernel calls kmap(), does the access and then calls kunmap(); or it calls kmap_atomic(), does
the access and then calls kunmap_atomic().
kmap() creates an attachment between an arbitrary inaccessible page and a range of virtual
addresses by installing a PTE in a special page table. The kernel can then access this page as it
wills. When it's finished, the kernel calls kunmap() to clear the PTE.
kmap_atomic() does something slightly different. In the interests of speed, it chooses one of two
strategies:
(1) If possible, kmap_atomic() attaches the requested page to one of DAMPR5 through DAMPR10
register pairs; and the matching kunmap_atomic() clears the DAMPR. This makes high memory
support really fast as there's no need to flush the TLB or modify the page tables. The DAMLR
registers being used for this are preset during boot and don't change over the lifetime of the
process. There's a direct mapping between the first few kmap_atomic() types, DAMR number and
virtual address slot.
However, there are more kmap_atomic() types defined than there are DAMR registers available,
so we fall back to:
(2) kmap_atomic() uses a slot in the secondary frame (determined by the type parameter), and then
locks an entry in the TLB to translate that slot to the specified page. The number of slots is
obviously limited, and their positions are controlled such that each slot is matched by a
different line in the TLB. kunmap() ejects the entry from the TLB.
Note that the first three kmap atomic types are really just declared as placeholders. The DAMPR
registers involved are actually modified directly.
Also note that kmap() itself may sleep, kmap_atomic() may never sleep and both always succeed;
furthermore, a driver using kmap() may sleep before calling kunmap(), but may not sleep before
calling kunmap_atomic() if it had previously called kmap_atomic().
===============================
USING MORE THAN 256MB OF MEMORY
===============================
The kernel cannot access more than 256MB of memory directly. The physical layout, however, permits
up to 3GB of SDRAM (possibly 3.25GB) to be made available. By using CONFIG_HIGHMEM, the kernel can
allow userspace (by way of page tables) and itself (by way of kmap) to deal with the memory
allocation.
External devices can, of course, still DMA to and from all of the SDRAM, even if the kernel can't
see it directly. The kernel translates page references into real addresses for communicating to the
devices.
===================
PAGE TABLE TOPOLOGY
===================
The page tables are arranged in 2-layer format. There is a middle layer (PMD) that would be used in
3-layer format tables but that is folded into the top layer (PGD) and so consumes no extra memory
or processing power.
+------+ PGD PMD
| TTBR |--->+-------------------+
+------+ | | : STE |
| PGE0 | PME0 : STE |
| | : STE |
+-------------------+ Page Table
| | : STE -------------->+--------+ +0x0000
| PGE1 | PME0 : STE -----------+ | PTE0 |
| | : STE -------+ | +--------+
+-------------------+ | | | PTE63 |
| | : STE | | +-->+--------+ +0x0100
| PGE2 | PME0 : STE | | | PTE64 |
| | : STE | | +--------+
+-------------------+ | | PTE127 |
| | : STE | +------>+--------+ +0x0200
| PGE3 | PME0 : STE | | PTE128 |
| | : STE | +--------+
+-------------------+ | PTE191 |
+--------+ +0x0300
Each Page Directory (PGD) is 16KB (page size) in size and is divided into 64 entries (PGEs). Each
PGE contains one Page Mid Directory (PMD).
Each PMD is 256 bytes in size and contains a single entry (PME). Each PME holds 64 FR451 MMU
segment table entries of 4 bytes apiece. Each PME "points to" a page table. In practice, each STE
points to a subset of the page table, the first to PT+0x0000, the second to PT+0x0100, the third to
PT+0x200, and so on.
Each PGE and PME covers 64MB of the total virtual address space.
Each Page Table (PTD) is 16KB (page size) in size, and is divided into 4096 entries (PTEs). Each
entry can point to one 16KB page. In practice, each Linux page table is subdivided into 64 FR451
MMU page tables. But they are all grouped together to make management easier, in particular rmap
support is then trivial.
Grouping page tables in this fashion makes PGE caching in SCR0/SCR1 more efficient because the
coverage of the cached item is greater.
Page tables for the vmalloc area are allocated at boot time and shared between all mm_structs.
=================
USER SPACE LAYOUT
=================
For MMU capable Linux, the regions userspace code are allowed to access are kept entirely separate
from those dedicated to the kernel:
VIRTUAL ADDRESS SIZE PURPOSE
================= ===== ===================================
00000000-00003fff 4KB NULL pointer access trap
00004000-01ffffff ~32MB lower mmap space (grows up)
02000000-021fffff 2MB Stack space (grows down from top)
02200000-nnnnnnnn Executable mapping
nnnnnnnn- brk space (grows up)
-bfffffff upper mmap space (grows down)
This is so arranged so as to make best use of the 16KB page tables and the way in which PGEs/PMEs
are cached by the TLB handler. The lower mmap space is filled first, and then the upper mmap space
is filled.
===============================
GDB-STUB MMU DEBUGGING SERVICES
===============================
The gdb-stub included in this kernel provides a number of services to aid in the debugging of MMU
related kernel services:
(*) Every time the kernel stops, certain state information is dumped into __debug_mmu. This
variable is defined in arch/frv/kernel/gdb-stub.c. Note that the gdbinit file in this
directory has some useful macros for dealing with this.
(*) __debug_mmu.tlb[]
This receives the current TLB contents. This can be viewed with the _tlb GDB macro:
(gdb) _tlb
tlb[0x00]: 01000005 00718203 01000002 00718203
tlb[0x01]: 01004002 006d4201 01004005 006d4203
tlb[0x02]: 01008002 006d0201 01008006 00004200
tlb[0x03]: 0100c006 007f4202 0100c002 0064c202
tlb[0x04]: 01110005 00774201 01110002 00774201
tlb[0x05]: 01114005 00770201 01114002 00770201
tlb[0x06]: 01118002 0076c201 01118005 0076c201
...
tlb[0x3d]: 010f4002 00790200 001f4002 0054ca02
tlb[0x3e]: 010f8005 0078c201 010f8002 0078c201
tlb[0x3f]: 001fc002 0056ca01 001fc005 00538a01
(*) __debug_mmu.iamr[]
(*) __debug_mmu.damr[]
These receive the current IAMR and DAMR contents. These can be viewed with the _amr
GDB macro:
(gdb) _amr
AMRx DAMR IAMR
==== ===================== =====================
amr0 : L:c0000000 P:00000cb9 : L:c0000000 P:000004b9
amr1 : L:01070005 P:006f9203 : L:0102c005 P:006a1201
amr2 : L:d8d00000 P:00000000 : L:d8d00000 P:00000000
amr3 : L:d8d04000 P:00534c0d : L:00000000 P:00000000
amr4 : L:d8d08000 P:00554c0d : L:00000000 P:00000000
amr5 : L:d8d0c000 P:00554c0d : L:00000000 P:00000000
amr6 : L:d8d10000 P:00000000 : L:00000000 P:00000000
amr7 : L:d8d14000 P:00000000 : L:00000000 P:00000000
amr8 : L:d8d18000 P:00000000
amr9 : L:d8d1c000 P:00000000
amr10: L:d8d20000 P:00000000
amr11: L:e0000000 P:e0000ccd
(*) The current task's page directory is bound to DAMR3.
This can be viewed with the _pgd GDB macro:
(gdb) _pgd
$3 = {{pge = {{ste = {0x554001, 0x554101, 0x554201, 0x554301, 0x554401,
0x554501, 0x554601, 0x554701, 0x554801, 0x554901, 0x554a01,
0x554b01, 0x554c01, 0x554d01, 0x554e01, 0x554f01, 0x555001,
0x555101, 0x555201, 0x555301, 0x555401, 0x555501, 0x555601,
0x555701, 0x555801, 0x555901, 0x555a01, 0x555b01, 0x555c01,
0x555d01, 0x555e01, 0x555f01, 0x556001, 0x556101, 0x556201,
0x556301, 0x556401, 0x556501, 0x556601, 0x556701, 0x556801,
0x556901, 0x556a01, 0x556b01, 0x556c01, 0x556d01, 0x556e01,
0x556f01, 0x557001, 0x557101, 0x557201, 0x557301, 0x557401,
0x557501, 0x557601, 0x557701, 0x557801, 0x557901, 0x557a01,
0x557b01, 0x557c01, 0x557d01, 0x557e01, 0x557f01}}}}, {pge = {{
ste = {0x0 <repeats 64 times>}}}} <repeats 51 times>, {pge = {{ste = {
0x248001, 0x248101, 0x248201, 0x248301, 0x248401, 0x248501,
0x248601, 0x248701, 0x248801, 0x248901, 0x248a01, 0x248b01,
0x248c01, 0x248d01, 0x248e01, 0x248f01, 0x249001, 0x249101,
0x249201, 0x249301, 0x249401, 0x249501, 0x249601, 0x249701,
0x249801, 0x249901, 0x249a01, 0x249b01, 0x249c01, 0x249d01,
0x249e01, 0x249f01, 0x24a001, 0x24a101, 0x24a201, 0x24a301,
0x24a401, 0x24a501, 0x24a601, 0x24a701, 0x24a801, 0x24a901,
0x24aa01, 0x24ab01, 0x24ac01, 0x24ad01, 0x24ae01, 0x24af01,
0x24b001, 0x24b101, 0x24b201, 0x24b301, 0x24b401, 0x24b501,
0x24b601, 0x24b701, 0x24b801, 0x24b901, 0x24ba01, 0x24bb01,
0x24bc01, 0x24bd01, 0x24be01, 0x24bf01}}}}, {pge = {{ste = {
0x0 <repeats 64 times>}}}} <repeats 11 times>}
(*) The PTD last used by the instruction TLB miss handler is attached to DAMR4.
(*) The PTD last used by the data TLB miss handler is attached to DAMR5.
These can be viewed with the _ptd_i and _ptd_d GDB macros:
(gdb) _ptd_d
$5 = {{pte = 0x0} <repeats 127 times>, {pte = 0x539b01}, {
pte = 0x0} <repeats 896 times>, {pte = 0x719303}, {pte = 0x6d5303}, {
pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {
pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {pte = 0x6a1303}, {
pte = 0x0} <repeats 12 times>, {pte = 0x709303}, {pte = 0x0}, {pte = 0x0},
{pte = 0x6fd303}, {pte = 0x6f9303}, {pte = 0x6f5303}, {pte = 0x0}, {
pte = 0x6ed303}, {pte = 0x531b01}, {pte = 0x50db01}, {
pte = 0x0} <repeats 13 times>, {pte = 0x5303}, {pte = 0x7f5303}, {
pte = 0x509b01}, {pte = 0x505b01}, {pte = 0x7c9303}, {pte = 0x7b9303}, {
pte = 0x7b5303}, {pte = 0x7b1303}, {pte = 0x7ad303}, {pte = 0x0}, {
pte = 0x0}, {pte = 0x7a1303}, {pte = 0x0}, {pte = 0x795303}, {pte = 0x0}, {
pte = 0x78d303}, {pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {
pte = 0x0}, {pte = 0x775303}, {pte = 0x771303}, {pte = 0x76d303}, {
pte = 0x0}, {pte = 0x765303}, {pte = 0x7c5303}, {pte = 0x501b01}, {
pte = 0x4f1b01}, {pte = 0x4edb01}, {pte = 0x0}, {pte = 0x4f9b01}, {
pte = 0x4fdb01}, {pte = 0x0} <repeats 2992 times>}
......@@ -5799,10 +5799,6 @@ F: fs/crypto/
F: include/linux/fscrypt*.h
F: Documentation/filesystems/fscrypt.rst
FUJITSU FR-V (FRV) PORT
S: Orphan
F: arch/frv/
FUJITSU LAPTOP EXTRAS
M: Jonathan Woithe <jwoithe@just42.net>
L: platform-driver-x86@vger.kernel.org
......
# SPDX-License-Identifier: GPL-2.0
config FRV
bool
default y
select HAVE_IDE
select HAVE_ARCH_TRACEHOOK
select HAVE_PERF_EVENTS
select HAVE_UID16
select VIRT_TO_BUS
select GENERIC_IRQ_SHOW
select HAVE_DEBUG_BUGVERBOSE
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select GENERIC_CPU_DEVICES
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_WANT_IPC_PARSE_VERSION
select OLD_SIGSUSPEND3
select OLD_SIGACTION
select HAVE_DEBUG_STACKOVERFLOW
select ARCH_NO_COHERENT_DMA_MMAP
config CPU_BIG_ENDIAN
def_bool y
config ZONE_DMA
bool
default y
config RWSEM_GENERIC_SPINLOCK
bool
default y
config RWSEM_XCHGADD_ALGORITHM
bool
config GENERIC_HWEIGHT
bool
default y
config GENERIC_CALIBRATE_DELAY
bool
default n
config TIME_LOW_RES
bool
default y
config QUICKLIST
bool
default y
config ARCH_HAS_ILOG2_U32
bool
default y
config ARCH_HAS_ILOG2_U64
bool
default y
config HZ
int
default 1000
source "init/Kconfig"
source "kernel/Kconfig.freezer"
menu "Fujitsu FR-V system setup"
config MMU
bool "MMU support"
help
This options switches on and off support for the FR-V MMU
(effectively switching between vmlinux and uClinux). Not all FR-V
CPUs support this. Currently only the FR451 has a sufficiently
featured MMU.
config FRV_OUTOFLINE_ATOMIC_OPS
bool "Out-of-line the FRV atomic operations"
default n
help
Setting this option causes the FR-V atomic operations to be mostly
implemented out-of-line.
See Documentation/frv/atomic-ops.txt for more information.
config HIGHMEM
bool "High memory support"
depends on MMU
default y
help
If you wish to use more than 256MB of memory with your MMU based
system, you will need to select this option. The kernel can only see
the memory between 0xC0000000 and 0xD0000000 directly... everything
else must be kmapped.
The arch is, however, capable of supporting up to 3GB of SDRAM.
config HIGHPTE
bool "Allocate page tables in highmem"
depends on HIGHMEM
default y
help
The VM uses one page of memory for each page table. For systems
with a lot of RAM, this can be wasteful of precious low memory.
Setting this option will put user-space page tables in high memory.
source "mm/Kconfig"
choice
prompt "uClinux kernel load address"
depends on !MMU
default UCPAGE_OFFSET_C0000000
help
This option sets the base address for the uClinux kernel. The kernel
will rearrange the SDRAM layout to start at this address, and move
itself to start there. It must be greater than 0, and it must be
sufficiently less than 0xE0000000 that the SDRAM does not intersect
the I/O region.
The base address must also be aligned such that the SDRAM controller
can decode it. For instance, a 512MB SDRAM bank must be 512MB aligned.
config UCPAGE_OFFSET_20000000
bool "0x20000000"
config UCPAGE_OFFSET_40000000
bool "0x40000000"
config UCPAGE_OFFSET_60000000
bool "0x60000000"
config UCPAGE_OFFSET_80000000
bool "0x80000000"
config UCPAGE_OFFSET_A0000000
bool "0xA0000000"
config UCPAGE_OFFSET_C0000000
bool "0xC0000000 (Recommended)"
endchoice
config PAGE_OFFSET
hex
default 0x20000000 if UCPAGE_OFFSET_20000000
default 0x40000000 if UCPAGE_OFFSET_40000000
default 0x60000000 if UCPAGE_OFFSET_60000000
default 0x80000000 if UCPAGE_OFFSET_80000000
default 0xA0000000 if UCPAGE_OFFSET_A0000000
default 0xC0000000
config PROTECT_KERNEL
bool "Protect core kernel against userspace"
depends on !MMU
default y
help
Selecting this option causes the uClinux kernel to change the
permittivity of DAMPR register covering the core kernel image to
prevent userspace accessing the underlying memory directly.
choice
prompt "CPU Caching mode"
default FRV_DEFL_CACHE_WBACK
help
This option determines the default caching mode for the kernel.
Write-Back caching mode involves the all reads and writes causing
the affected cacheline to be read into the cache first before being
operated upon. Memory is not then updated by a write until the cache
is filled and a cacheline needs to be displaced from the cache to
make room. Only at that point is it written back.
Write-Behind caching is similar to Write-Back caching, except that a
write won't fetch a cacheline into the cache if there isn't already
one there; it will write directly to memory instead.
Write-Through caching only fetches cachelines from memory on a
read. Writes always get written directly to memory. If the affected
cacheline is also in cache, it will be updated too.
The final option is to turn of caching entirely.
Note that not all CPUs support Write-Behind caching. If the CPU on
which the kernel is running doesn't, it'll fall back to Write-Back
caching.
config FRV_DEFL_CACHE_WBACK
bool "Write-Back"
config FRV_DEFL_CACHE_WBEHIND
bool "Write-Behind"
config FRV_DEFL_CACHE_WTHRU
bool "Write-Through"
config FRV_DEFL_CACHE_DISABLED
bool "Disabled"
endchoice
menu "CPU core support"
config CPU_FR401
bool "Include FR401 core support"
depends on !MMU
default y
help
This enables support for the FR401, FR401A and FR403 CPUs
config CPU_FR405
bool "Include FR405 core support"
depends on !MMU
default y
help
This enables support for the FR405 CPU
config CPU_FR451
bool "Include FR451 core support"
default y
help
This enables support for the FR451 CPU
config CPU_FR451_COMPILE
bool "Specifically compile for FR451 core"
depends on CPU_FR451 && !CPU_FR401 && !CPU_FR405 && !CPU_FR551
default y
help
This causes appropriate flags to be passed to the compiler to
optimise for the FR451 CPU
config CPU_FR551
bool "Include FR551 core support"
depends on !MMU
default y
help
This enables support for the FR555 CPU
config CPU_FR551_COMPILE
bool "Specifically compile for FR551 core"
depends on CPU_FR551 && !CPU_FR401 && !CPU_FR405 && !CPU_FR451
default y
help
This causes appropriate flags to be passed to the compiler to
optimise for the FR555 CPU
config FRV_L1_CACHE_SHIFT
int
default "5" if CPU_FR401 || CPU_FR405 || CPU_FR451
default "6" if CPU_FR551
endmenu
choice
prompt "System support"
default MB93091_VDK
config MB93091_VDK
bool "MB93091 CPU board with or without motherboard"
config MB93093_PDK
bool "MB93093 PDK unit"
endchoice
if MB93091_VDK
choice
prompt "Motherboard support"
default MB93090_MB00
config MB93090_MB00
bool "Use the MB93090-MB00 motherboard"
help
Select this option if the MB93091 CPU board is going to be used with
a MB93090-MB00 VDK motherboard
config MB93091_NO_MB
bool "Use standalone"
help
Select this option if the MB93091 CPU board is going to be used
without a motherboard
endchoice
endif
config FUJITSU_MB93493
bool "MB93493 Multimedia chip"
help
Select this option if the MB93493 multimedia chip is going to be
used.
choice
prompt "GP-Relative data support"
default GPREL_DATA_8
help
This option controls what data, if any, should be placed in the GP
relative data sections. Using this means that the compiler can
generate accesses to the data using GR16-relative addressing which
is faster than absolute instructions and saves space (2 instructions
per access).
However, the GPREL region is limited in size because the immediate
value used in the load and store instructions is limited to a 12-bit
signed number.
So if the linker starts complaining that accesses to GPREL data are
out of range, try changing this option from the default.
Note that modules will always be compiled with this feature disabled
as the module data will not be in range of the GP base address.
config GPREL_DATA_8
bool "Put data objects of up to 8 bytes into GP-REL"
config GPREL_DATA_4
bool "Put data objects of up to 4 bytes into GP-REL"
config GPREL_DATA_NONE
bool "Don't use GP-REL"
endchoice
config FRV_ONCPU_SERIAL
bool "Use on-CPU serial ports"
select SERIAL_8250
default y
config PCI
bool "Use PCI"
depends on MB93090_MB00
default y
select GENERIC_PCI_IOMAP
help
Some FR-V systems (such as the MB93090-MB00 VDK) have PCI
onboard. If you have one of these boards and you wish to use the PCI
facilities, say Y here.
config RESERVE_DMA_COHERENT
bool "Reserve DMA coherent memory"
depends on PCI && !MMU
default y
help
Many PCI drivers require access to uncached memory for DMA device
communications (such as is done with some Ethernet buffer rings). If
a fully featured MMU is available, this can be done through page
table settings, but if not, a region has to be set aside and marked
with a special DAMPR register.
Setting this option causes uClinux to set aside a portion of the
available memory for use in this manner. The memory will then be
unavailable for normal kernel use.
source "drivers/pci/Kconfig"
source "drivers/pcmcia/Kconfig"
menu "Power management options"
config ARCH_SUSPEND_POSSIBLE
def_bool y
source kernel/power/Kconfig
endmenu
endmenu
menu "Executable formats"
source "fs/Kconfig.binfmt"
endmenu
source "net/Kconfig"
source "drivers/Kconfig"
source "fs/Kconfig"
source "arch/frv/Kconfig.debug"
source "security/Kconfig"
source "crypto/Kconfig"
source "lib/Kconfig"
# SPDX-License-Identifier: GPL-2.0
menu "Kernel hacking"
source "lib/Kconfig.debug"
config GDBSTUB
bool "Remote GDB kernel debugging"
depends on DEBUG_KERNEL
select DEBUG_INFO
select FRAME_POINTER
help
If you say Y here, it will be possible to remotely debug the kernel
using gdb. This enlarges your kernel ELF image disk size by several
megabytes and requires a machine with more than 16 MB, better 32 MB
RAM to avoid excessive linking time. This is only useful for kernel
hackers. If unsure, say N.
choice
prompt "GDB stub port"
default GDBSTUB_UART1
depends on GDBSTUB
help
Select the on-CPU port used for GDB-stub
config GDBSTUB_UART0
bool "/dev/ttyS0"
config GDBSTUB_UART1
bool "/dev/ttyS1"
endchoice
config GDBSTUB_IMMEDIATE
bool "Break into GDB stub immediately"
depends on GDBSTUB
help
If you say Y here, GDB stub will break into the program as soon as
possible, leaving the program counter at the beginning of
start_kernel() in init/main.c.
config GDB_CONSOLE
bool "Console output to GDB"
depends on GDBSTUB
help
If you are using GDB for remote debugging over a serial port and
would like kernel messages to be formatted into GDB $O packets so
that GDB prints them as program output, say 'Y'.
endmenu
#
# frv/Makefile
#
# This file is included by the global makefile so that you can add your own
# architecture-specific flags and dependencies. Remember to do have actions
# for "archclean" and "archdep" for cleaning up and making dependencies for
# this architecture
#
# This file is subject to the terms and conditions of the GNU General Public
# License. See the file "COPYING" in the main directory of this archive
# for more details.
#
# Copyright (c) 2003, 2004 Red Hat Inc.
# - Written by David Howells <dhowells@redhat.com>
# - Derived from arch/m68knommu/Makefile,
# Copyright (c) 1999,2001 D. Jeff Dionne <jeff@lineo.ca>,
# Rt-Control Inc. / Lineo, Inc.
#
# Copyright (C) 1998,1999 D. Jeff Dionne <jeff@uclinux.org>,
# Kenneth Albanowski <kjahds@kjahds.com>,
#
# Based on arch/m68k/Makefile:
# Copyright (C) 1994 by Hamish Macdonald
#
ifdef CONFIG_MMU
UTS_SYSNAME = -DUTS_SYSNAME=\"Linux\"
else
UTS_SYSNAME = -DUTS_SYSNAME=\"uClinux\"
endif
KBUILD_AFLAGS_MODULE += -G0 -mlong-calls
KBUILD_CFLAGS_MODULE += -G0 -mlong-calls
ifdef CONFIG_GPREL_DATA_8
KBUILD_CFLAGS += -G8
else
ifdef CONFIG_GPREL_DATA_4
KBUILD_CFLAGS += -G4
else
ifdef CONFIG_GPREL_DATA_NONE
KBUILD_CFLAGS += -G0
endif
endif
endif
#LDFLAGS_vmlinux := -Map linkmap.txt
ifdef CONFIG_GC_SECTIONS
KBUILD_CFLAGS += -ffunction-sections -fdata-sections
endif
ifndef CONFIG_FRAME_POINTER
KBUILD_CFLAGS += -mno-linked-fp
endif
ifdef CONFIG_CPU_FR451_COMPILE
KBUILD_CFLAGS += -mcpu=fr450
KBUILD_AFLAGS += -mcpu=fr450
else
ifdef CONFIG_CPU_FR551_COMPILE
KBUILD_CFLAGS += -mcpu=fr550
KBUILD_AFLAGS += -mcpu=fr550
else
KBUILD_CFLAGS += -mcpu=fr400
KBUILD_AFLAGS += -mcpu=fr400
endif
endif
# pretend the kernel is going to run on an FR400 with no media-fp unit
# - reserve CC3 for use with atomic ops
# - all the extra registers are dealt with only at context switch time
KBUILD_CFLAGS += -mno-fdpic -mgpr-32 -msoft-float -mno-media
KBUILD_CFLAGS += -ffixed-fcc3 -ffixed-cc3 -ffixed-gr15 -ffixed-icc2
KBUILD_AFLAGS += -mno-fdpic
head-y := arch/frv/kernel/head.o
core-y += arch/frv/kernel/ arch/frv/mm/
libs-y += arch/frv/lib/
core-$(CONFIG_MB93090_MB00) += arch/frv/mb93090-mb00/
all: Image
Image: vmlinux
$(Q)$(MAKE) $(build)=arch/frv/boot $@
archclean:
$(Q)$(MAKE) $(clean)=arch/frv/boot
#
# arch/arm/boot/Makefile
#
# This file is subject to the terms and conditions of the GNU General Public
# License. See the file "COPYING" in the main directory of this archive
# for more details.
#
# Copyright (C) 1995-2000 Russell King
#
targets := Image zImage bootpImage
SYSTEM =$(LINUX)
ZTEXTADDR = 0x02080000
PARAMS_PHYS = 0x0207c000
INITRD_PHYS = 0x02180000
INITRD_VIRT = 0x02180000
OBJCOPYFLAGS :=-O binary -R .note -R .note.gnu.build-id -R .comment
#
# If you don't define ZRELADDR above,
# then it defaults to ZTEXTADDR
#
ifeq ($(ZRELADDR),)
ZRELADDR = $(ZTEXTADDR)
endif
export SYSTEM ZTEXTADDR ZBSSADDR ZRELADDR INITRD_PHYS INITRD_VIRT PARAMS_PHYS
Image: $(obj)/Image
targets: $(obj)/Image
$(obj)/Image: vmlinux FORCE
$(OBJCOPY) $(OBJCOPYFLAGS) -S vmlinux $@
#$(obj)/Image: $(CONFIGURE) $(SYSTEM)
# $(OBJCOPY) $(OBJCOPYFLAGS) -g -S $(SYSTEM) $@
bzImage: zImage
zImage: $(CONFIGURE) compressed/$(LINUX)
$(OBJCOPY) $(OBJCOPYFLAGS) -S compressed/$(LINUX) $@
bootpImage: bootp/bootp
$(OBJCOPY) $(OBJCOPYFLAGS) -S bootp/bootp $@
compressed/$(LINUX): $(LINUX) dep
@$(MAKE) -C compressed $(LINUX)
bootp/bootp: zImage initrd
@$(MAKE) -C bootp bootp
initrd:
@test "$(INITRD_VIRT)" != "" || (echo This architecture does not support INITRD; exit -1)
@test "$(INITRD)" != "" || (echo You must specify INITRD; exit -1)
#
# installation
#
install: $(CONFIGURE) Image
sh ./install.sh $(KERNELRELEASE) Image System.map "$(INSTALL_PATH)"
zinstall: $(CONFIGURE) zImage
sh ./install.sh $(KERNELRELEASE) zImage System.map "$(INSTALL_PATH)"
#
# miscellany
#
mrproper clean:
# @$(MAKE) -C compressed clean
# @$(MAKE) -C bootp clean
dep:
CONFIG_EXPERIMENTAL=y
CONFIG_SYSVIPC=y
CONFIG_POSIX_MQUEUE=y
CONFIG_LOG_BUF_SHIFT=14
# CONFIG_CC_OPTIMIZE_FOR_SIZE is not set
CONFIG_EXPERT=y
# CONFIG_HOTPLUG is not set
CONFIG_MMU=y
CONFIG_FRV_OUTOFLINE_ATOMIC_OPS=y
CONFIG_FRV_DEFL_CACHE_WTHRU=y
CONFIG_GPREL_DATA_4=y
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
CONFIG_INET=y
CONFIG_IP_PNP=y
# CONFIG_IPV6 is not set
# CONFIG_STANDALONE is not set
# CONFIG_PREVENT_FIRMWARE_BUILD is not set
CONFIG_NETDEVICES=y
CONFIG_NET_ETHERNET=y
CONFIG_MII=y
CONFIG_NET_PCI=y
CONFIG_NE2K_PCI=y
# CONFIG_INPUT is not set
# CONFIG_SERIO is not set
# CONFIG_VT is not set
CONFIG_SERIAL_8250_CONSOLE=y
CONFIG_SERIAL_8250_NR_UARTS=1
CONFIG_SERIAL_8250_RUNTIME_UARTS=1
CONFIG_SERIAL_8250_EXTENDED=y
CONFIG_SERIAL_8250_SHARE_IRQ=y
# CONFIG_LEGACY_PTYS is not set
CONFIG_TMPFS=y
CONFIG_NFS_FS=y
CONFIG_ROOT_NFS=y
CONFIG_DEBUG_KERNEL=y
# CONFIG_DEBUG_BUGVERBOSE is not set
CONFIG_DEBUG_STACKOVERFLOW=y
generic-y += device.h
generic-y += exec.h
generic-y += extable.h
generic-y += fb.h
generic-y += irq_work.h
generic-y += mcs_spinlock.h
generic-y += mm-arch-hooks.h
generic-y += preempt.h
generic-y += trace_clock.h
generic-y += word-at-a-time.h
generic-y += kprobes.h
#include <generated/asm-offsets.h>
/* atomic.h: atomic operation emulation for FR-V
*
* For an explanation of how atomic ops work in this arch, see:
* Documentation/frv/atomic-ops.txt
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _ASM_ATOMIC_H
#define _ASM_ATOMIC_H
#include <linux/types.h>
#include <asm/cmpxchg.h>
#include <asm/barrier.h>
#ifdef CONFIG_SMP
#error not SMP safe
#endif
#include <asm/atomic_defs.h>
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*
* We do not have SMP systems, so we don't have to deal with that.
*/
#define ATOMIC_INIT(i) { (i) }
#define atomic_read(v) READ_ONCE((v)->counter)
#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
static inline int atomic_inc_return(atomic_t *v)
{
return __atomic_add_return(1, &v->counter);
}
static inline int atomic_dec_return(atomic_t *v)
{
return __atomic_sub_return(1, &v->counter);
}
static inline int atomic_add_return(int i, atomic_t *v)
{
return __atomic_add_return(i, &v->counter);
}
static inline int atomic_sub_return(int i, atomic_t *v)
{
return __atomic_sub_return(i, &v->counter);
}
static inline int atomic_add_negative(int i, atomic_t *v)
{
return atomic_add_return(i, v) < 0;
}
static inline void atomic_inc(atomic_t *v)
{
atomic_inc_return(v);
}
static inline void atomic_dec(atomic_t *v)
{
atomic_dec_return(v);
}
#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
/*
* 64-bit atomic ops
*/
typedef struct {
long long counter;
} atomic64_t;
#define ATOMIC64_INIT(i) { (i) }
static inline long long atomic64_read(const atomic64_t *v)
{
long long counter;
asm("ldd%I1 %M1,%0"
: "=e"(counter)
: "m"(v->counter));
return counter;
}
static inline void atomic64_set(atomic64_t *v, long long i)
{
asm volatile("std%I0 %1,%M0"
: "=m"(v->counter)
: "e"(i));
}
static inline long long atomic64_inc_return(atomic64_t *v)
{
return __atomic64_add_return(1, &v->counter);
}
static inline long long atomic64_dec_return(atomic64_t *v)
{
return __atomic64_sub_return(1, &v->counter);
}
static inline long long atomic64_add_return(long long i, atomic64_t *v)
{
return __atomic64_add_return(i, &v->counter);
}
static inline long long atomic64_sub_return(long long i, atomic64_t *v)
{
return __atomic64_sub_return(i, &v->counter);
}
static inline long long atomic64_add_negative(long long i, atomic64_t *v)
{
return atomic64_add_return(i, v) < 0;
}
static inline void atomic64_inc(atomic64_t *v)
{
atomic64_inc_return(v);
}
static inline void atomic64_dec(atomic64_t *v)
{
atomic64_dec_return(v);
}
#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
#define atomic64_inc_and_test(v) (atomic64_inc_return((v)) == 0)
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
#define atomic_cmpxchg(v, old, new) (cmpxchg(&(v)->counter, old, new))
#define atomic_xchg(v, new) (xchg(&(v)->counter, new))
#define atomic64_cmpxchg(v, old, new) (__cmpxchg_64(old, new, &(v)->counter))
#define atomic64_xchg(v, new) (__xchg_64(new, &(v)->counter))
static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
{
int c, old;
c = atomic_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c;
}
static inline int atomic64_add_unless(atomic64_t *v, long long i, long long u)
{
long long c, old;
c = atomic64_read(v);
for (;;) {
if (unlikely(c == u))
break;
old = atomic64_cmpxchg(v, c, c + i);
if (likely(old == c))
break;
c = old;
}
return c != u;
}
static inline long long atomic64_dec_if_positive(atomic64_t *v)
{
long long c, old, dec;
c = atomic64_read(v);
for (;;) {
dec = c - 1;
if (unlikely(dec < 0))
break;
old = atomic64_cmpxchg((v), c, dec);
if (likely(old == c))
break;
c = old;
}
return dec;
}
#define ATOMIC_OP(op) \
static inline int atomic_fetch_##op(int i, atomic_t *v) \
{ \
return __atomic32_fetch_##op(i, &v->counter); \
} \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
(void)__atomic32_fetch_##op(i, &v->counter); \
} \
\
static inline long long atomic64_fetch_##op(long long i, atomic64_t *v) \
{ \
return __atomic64_fetch_##op(i, &v->counter); \
} \
static inline void atomic64_##op(long long i, atomic64_t *v) \
{ \
(void)__atomic64_fetch_##op(i, &v->counter); \
}
ATOMIC_OP(or)
ATOMIC_OP(and)
ATOMIC_OP(xor)
ATOMIC_OP(add)
ATOMIC_OP(sub)
#undef ATOMIC_OP
#endif /* _ASM_ATOMIC_H */
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