Since zEC12 we have the interlocked-access facility 2 which allows to
use the instructions ni/oi/xi to update a single byte in storage with
compare-and-swap semantics.
So change set_bit(), clear_bit() and change_bit() to generate such code
instead of a compare-and-swap loop (or using the load-and-* instruction
family), if possible.
This reduces the text segment by yet another 8KB (defconfig).
Alternatively the long displacement variants niy/oiy/xiy could have
been used, but the extended displacement field is usually not needed
and therefore would only increase the size of the text segment again.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Allow to generate code that only runs on zEC12 machines.
Also add a check which prevents the kernel to run on machines which
do not have any of the following new facilities installed:
- (48) decimal-floating-point zoned-conversion
- (49) execution-hint
- (49) load-and-trap
- (49) miscellaneous-instruction-extensions
- (49) processor-assist
- (50) constrained transactional-execution
- (73) transactional-execution
48, 49, 50 and 73 are the bit numbers of the facility indications for
each of the required facilities.
Note that we assume that user-space gets compiled with the same
compiler options, therefore we also test for a dfp facility even
if the kernel doesn't make use of it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Do the switch to z/Architecture (alias 64 bit) mode early in head.S.
If the machine is already running in 64 bit mode the sigp turns into
a nop. With this change it doesn't matter in which mode the kernel
is started.
Reviewd-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.
Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Remove the builtin tape ipl code. If somebody really wants to create a
tape which can be ipl'ed from, then this can be achieved by using zipl.
zipl can write an ipl record to a tape device and aftwards the kernel
image must be written to tape.
The steps are described in the "Linux on System z - Device Drivers,
Features, and Commands" book (SC33-8411).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The stfle() function writes into lowcore memory when stfl_fac_list
is initialized with "S390_lowcore.stfl_fac_list = 0". For older
compilers this triggers a lowcore exception. With newer compilers
and "-OXX" compile option the bug does not show up because
the "S390_lowcore.stfl_fac_list" initialization is removed by the
compiler. The reason for thatis the incorrect "=m"
(S390_lowcore.stfl_fac_list) constraint in the stfl inline assembly.
The following shows the disassembly of the stfle() optimized code
that is inlined in the lgr_info_get() function:
000000000011325c <lgr_info_get>:
11325c: eb 9f f0 60 00 24 stmg %r9,%r15,96(%r15)
113262: c0 d0 00 29 0e 47 larl %r13,634ef0 <servi..>
113268: a7 f1 3f c0 tml %r15,16320
11326c: b9 04 00 ef lgr %r14,%r15
113270: a7 84 00 01 je 113272 <lgr_info_g..>
113274: a7 fb ff c0 aghi %r15,-64
113278: b9 04 00 c2 lgr %r12,%r2
11327c: a7 29 00 01 lghi %r2,1
113280: e3 e0 f0 98 00 24 stg %r14,152(%r15)
113286: d7 97 c0 00 c0 00 xc 0(152,%r12),0(%r12)
11328c: c0 e5 00 28 db 4c brasl %r14,62e924 <add_e..>
113292: b2 b1 00 00 stfl 0
To fix the problem we now clear the S390_lowcore.stfl_fac_list at
startup in "head.S" for all machine types before lowcore protection
is enabled.
In addition to that the "=m" constraint is replaced by "+m".
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Another round of cleanup for entry[64].S, in particular the program check
handler looks more reasonable now. The code size for the 31 bit kernel
has been reduced by 616 byte and by 528 byte for the 64 bit version.
Even better the code is a bit faster as well.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch provides the architecture specific part of the s390 kdump
support.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The alignment is missing for various global symbols in s390 assembly code.
With a recent gcc and an instruction like stgrl this can lead to a
specification exception if the instruction uses such a mis-aligned address.
Specify the alignment explicitely and while add it define __ALIGN for s390
and use the ENTRY define to save some lines of code.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The latest binutils won't accept the stfl instruction with march=g5
which is the correct behaviour. Unfortunately head.S is assembled
with -march=g5 even if the target cpu is z900 or later. To get
31-bit kernels compiled again the easiest fix is to use the .insn
notation for the stfl instruction in head.S.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a kernel config option for the IBM zEnterprise 196. This will
produce faster code on newer compilers using the -march=z196 option.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Change default load address of the initrd in case of IPL from reader.
The new load address is directly behind the kernel image.
This way we can see immediatly if there are any problems with the code
which tries to rescue the initrd in case the bootmem bitmap would
overlap with the initrd.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix two bugs with the kernel image compression:
1) reset the bss section of the compressed vmlinux
2) clear the high half of the registers for 64 bit early enough
for the decompression step
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add the "bzImage" compile target and the necessary code to generate
compressed kernel images. The old style uncompressed "image" target
is preserved, a simple make will build them both.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move the ebcdic to ascii conversion of the kernel parameter line from
head.S to early.c and convert the assembler code to C.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use asm offsets to make sure the offset defines to struct _lowcore and
its layout don't get out of sync.
Also add a BUILD_BUG_ON() which checks that the size of the structure
is sane.
And while being at it change those sites which use odd casts to access
the current lowcore. These should use S390_lowcore instead.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Saves us more than 65k pointless IPIs.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This adds a mini sclp device driver for very early use. The primary
and probably only use will be to emit a message to the console if the
cpu doesn't provide the minimum required capabilities to run the kernel.
After printing the message a disabled wait will be loaded and the
machine stops operating.
Printing the message is also part of this patch.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This has the consequence of changing the section name use for head
code from ".text.head" to ".head.text". Since this commit changes all
users in the architecture, this change should be harmless.
Signed-off-by: Tim Abbott <tabbott@mit.edu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Start the cpu time accounting very early to catch the cpu time spent
for the initial kernel setup. To make the output of /proc/uptime
match the sum of all cpu accounting values of the boot cpu reset
xtime and wall_to_monotonic to sane values based on the TOD clock.
The values set by timekeeping_init are off by up to a second.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a read_persistent_clock function that does not just return 0.
Since timekeeping_init calls the function before time_init has been
called move reset_tod_clock to early.c to make sure that the TOD
clock is running when read_persistent_clock is invoked.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The lowcore.h header has quite a lot of whitespace damage and a rather
wild collection of entries. Remove all that whitespace and tidy up the
order of the lowcore fields.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch adds the code generation option for IBM System z10 and
adds a check in head[31,64].S to prevents the execution of a kernel
compiled for a new processor type on an old machine.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The SALIPL entry point has an needless memory detection routine as we
later check the memory size again. The SALIPL code also uses diagnose
0x060 if we are running under VM, but this diagnose is not compatible
with the 64 bit addressing mode. The solution is to get rid of this
code and rely on the memory detection in the startup code.
Signed-off-by: Christian Borntraeger <cborntra@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Convert GET_IPL_DEVICE assembler macro to C function.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move initrd if the bitmap of the bootmem allocator would overwrite it.
In addition this patch sets the default size and address of the initrd to 0.
Therefore all boot loaders must set the initrd size and address correctly.
This is especially relevant for ftp boot via HMC/SE, where this change
requires a special patch file entry in the .ins file which sets these two
values contained at address 0x10408 and 0x10410.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
There is almost no room left for any new code between 0x10000
and 0x10480. Move the code from 0x10000 to 0x11000.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Sanitize some s390 Kconfig options. We have ARCH_S390, ARCH_S390X,
ARCH_S390_31, 64BIT, S390_SUPPORT and COMPAT. Replace these 6 options by
S390, 64BIT and COMPAT.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Merge common parts of head.S and head64.S into head.S and move architecture
specific parts to head31.S and head64.S respectively. Saves us ~500 lines
of duplicated assembly code.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Don't switch back to 24 bit addressing mode when waiting for an external
interrupt and set the correct bit in wait PSW (external mask instead of I/O
mask).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The patch that introduced waiting for interrupts after resetting the reader
can cause the boot to fail because the system is waiting for an interrupt that
will never arrive. Add code to check if an interrupt is supposed to arrive
before waiting endlessly.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Limit reported memory size to 2GB if running in 31 bit mode.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The kernel uses the SIGP external call order code to signal other CPUs. When
running with dedicated CPUs external calls don't get delivered immediately but
within a fixed polling invervall. This can lead to delays where the system
appears to do nothing. Replace the SIGP external call order with the SIGP
emergency call order since this one gets delivered immediately.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Wait for interrupt and clear status pending after resetting the reader.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The kernel takes a very long time to boot if the memory size is bigger then
32767 MB. The memory size is contained in a structure created by an sclp
call. The kernel accesses the field with a LH instrution which performs a
sign extension of a 16 bit word. In the case of a memory size with bit 2^15
set this results in a very large value and the memory detection just loops for
a long time. In addition if more then 64 GB are used on a 64 bit system the
memory size is read from an incorrect storage location.
Use zero-extention to read the 16 bit memory size and the correct offset to
read the 4 byte memory size on 64 bit.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Heiko Carstens