linux.git/include/asm-s390/processor.h, branch v2.6.21.7

[S390] New get_cpu_id() inline assembly

2007-02-21T09:55:18+00:00

Replace two stidp inline assemblies with one global implementation.

Signed-off-by: Michael Holzheu 
Signed-off-by: Martin Schwidefsky

[S390] Convert memory detection into C code.

2007-02-05T20:18:37+00:00

Hopefully this will make it more maintainable and less error prone.
Code makes use of search_exception_tables(). Since it calls this
function before the kernel exeception table is sorted, there is an
early call to sort_main_extable().

This way it's easy to use the already present infrastructure of fixup
sections. Also this would allows to easily convert the rest of
head[31|64].S into C code.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

[S390] Calibrate delay and bogomips.

2007-02-05T20:18:31+00:00

Preset the bogomips number to the cpu capacity value reported by
store system information in SYSIB 1.2.2. This value is constant
for a particular machine model and can be used to determine
relative performance differences between machines.

Signed-off-by: Martin Schwidefsky

[S390] noexec protection

2007-02-05T20:18:17+00:00

This provides a noexec protection on s390 hardware. Our hardware does
not have any bits left in the pte for a hw noexec bit, so this is a
different approach using shadow page tables and a special addressing
mode that allows separate address spaces for code and data.

As a special feature of our "secondary-space" addressing mode, separate
page tables can be specified for the translation of data addresses
(storage operands) and instruction addresses. The shadow page table is
used for the instruction addresses and the standard page table for the
data addresses.
The shadow page table is linked to the standard page table by a pointer
in page->lru.next of the struct page corresponding to the page that
contains the standard page table (since page->private is not really
private with the pte_lock and the page table pages are not in the LRU
list).
Depending on the software bits of a pte, it is either inserted into
both page tables or just into the standard (data) page table. Pages of
a vma that does not have the VM_EXEC bit set get mapped only in the
data address space. Any try to execute code on such a page will cause a
page translation exception. The standard reaction to this is a SIGSEGV
with two exceptions: the two system call opcodes 0x0a77 (sys_sigreturn)
and 0x0aad (sys_rt_sigreturn) are allowed. They are stored by the
kernel to the signal stack frame. Unfortunately, the signal return
mechanism cannot be modified to use an SA_RESTORER because the
exception unwinding code depends on the system call opcode stored
behind the signal stack frame.

This feature requires that user space is executed in secondary-space
mode and the kernel in home-space mode, which means that the addressing
modes need to be switched and that the noexec protection only works
for user space.
After switching the addressing modes, we cannot use the mvcp/mvcs
instructions anymore to copy between kernel and user space. A new
mvcos instruction has been added to the z9 EC/BC hardware which allows
to copy between arbitrary address spaces, but on older hardware the
page tables need to be walked manually.

Signed-off-by: Gerald Schaefer 
Signed-off-by: Martin Schwidefsky

[S390] Add set_fs(USER_DS) to start_thread().

2007-02-05T20:17:38+00:00

Currently works anyway since search_binary_handler has a
set_fs(USER_DS). But start_thread() is the place where this should be
done. Following all other architectures...

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

[S390] Small barrier() and cpu_relax() cleanup.

2007-02-05T20:17:20+00:00

cpu_relax() has barrier() semantics hence there is no need to use both
of them in conjunction in sclp_sync_wait(). Also change cpu_relax()
so it's more obvious that it has barrier semantics.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

[S390] Inline assembly cleanup.

2006-09-28T14:56:43+00:00

Major cleanup of all s390 inline assemblies. They now have a common
coding style. Quite a few have been shortened, mainly by using register
asm variables. Use of the EX_TABLE macro helps  as well. The atomic ops,
bit ops and locking inlines new use the Q-constraint if a newer gcc
is used.  That results in slightly better code.

Thanks to Christian Borntraeger for proof reading the changes.

Signed-off-by: Martin Schwidefsky

[PATCH] bootmem: use MAX_DMA_ADDRESS instead of LOW32LIMIT

2006-09-26T15:48:49+00:00

Introduce ARCH_LOW_ADDRESS_LIMIT which can be set per architecture to
override the 4GB default limit used by the bootmem allocater within
__alloc_bootmem_low() and __alloc_bootmem_low_node().  E.g.  s390 needs a
2GB limit instead of 4GB.

Acked-by: Ingo Molnar 
Cc: Martin Schwidefsky 
Signed-off-by: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[S390] EX_TABLE macro.

2006-09-20T13:58:20+00:00

Add EX_TABLE helper macro to simplify creation of inline assembly
exception table entries.

Signed-off-by: Martin Schwidefsky

[S390] cpu_relax() is supposed to have barrier() semantics.

2006-07-12T14:39:58+00:00

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky