Rework the dump_trace() stack unwinder interface to support different
unwinding algorithms. The new interface looks like this:

	struct unwind_state state;
	unwind_for_each_frame(&state, task, regs, start_stack)
		do_something(state.sp, state.ip, state.reliable);

The unwind_bc.c file contains the implementation for the classic
back-chain unwinder.

One positive side effect of the new code is it now handles ftraced
functions gracefully. It prints the real name of the return function
instead of 'return_to_handler'.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Change the __EMIT_BUG inline assembly to emit mergeable __bug_table
entries with type @progbits and specify the size of each entry.
The entry size is encoded sh_entsize field of the section definition,
it allows to identify which struct bug_entry to use to decode the
entries. This will be needed for the objtool support.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The text_dma.S code uses its own macro to generate an inline version of an
expoline. To make it easier to identify all expolines in the kernel use a
thunk and a branch to the thunk just like the rest of the kernel code does
it.

The name of the text_dma.S expoline thunk is __dma__s390_indirect_jump_r14
and the section is named .dma.text.__s390_indirect_jump_r14.

This will be needed for the objtool support.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The assembler version of the expoline thunk use the naming
__s390x_indirect_jump_rxuse_ry while the compiler generates names
like __s390_indirect_jump_rx_use_ry. Make the naming more consistent.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The assembler code in arch/s390 misses proper ENDPROC statements
to properly end functions in a few places. Add them.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The following warning occurred on s390:
WARNING: CPU: 0 PID: 804 at kernel/locking/lockdep.c:1025 lockdep_register_key+0x30/0x150

This is because the check in static_obj() assumes that all memory within
[_stext, _end] belongs to static objects, which at least for s390 isn't
true. The init section is also part of this range, and freeing it allows
the buddy allocator to allocate memory from it. We have virt == phys for
the kernel on s390, so that such allocations would then have addresses
within the range [_stext, _end].

To fix this, introduce arch_is_kernel_initmem_freed(), similar to
arch_is_kernel_text/data(), and add it to the checks in static_obj().
This will always return 0 on architectures that do not define
arch_is_kernel_initmem_freed. On s390, it will return 1 if initmem has
been freed and the address is in the range [__init_begin, __init_end].
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch adds support for relocating the kernel to a random address.
The random kernel offset is obtained from cpacf, using either TRNG, PRNO,
or KMC_PRNG, depending on supported MSA level.

KERNELOFFSET is added to vmcoreinfo, for crash --kaslr support.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

With a relocatable kernel that could reside at any place in memory, code
and data that has to stay below 2 GB needs special handling.

This patch introduces .dma sections for such text, data and ex_table.
The sections will be part of the decompressor kernel, so they will not
be relocated and stay below 2 GB. Their location is passed over to the
decompressed / relocated kernel via the .boot.preserved.data section.

The duald and aste for control register setup also need to stay below
2 GB, so move the setup code from arch/s390/kernel/head64.S to
arch/s390/boot/head.S. The duct and linkage_stack could reside above
2 GB, but their content has to be preserved for the decompresed kernel,
so they are also moved into the .dma section.

The start and end address of the .dma sections is added to vmcoreinfo,
for crash support, to help debugging in case the kernel crashed there.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The sccbs for init/read/sdias/early have to be located below 2 GB, and
they are currently defined as a static buffer.

With a relocatable kernel that could reside at any place in memory, this
will no longer guarantee the location below 2 GB, so use a dynamic
GFP_DMA allocation instead.

The sclp_early_sccb buffer needs special handling, as it can be used
very early, and by both the decompressor and also the decompressed
kernel. Therefore, a fixed 4 KB buffer is introduced at 0x11000, the
former PARMAREA_END. The new PARMAREA_END is now 0x12000, and it is
renamed to HEAD_END, as it is rather the end of head.S and not the end
of the parmarea.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

With a relocatable kernel that could reside at any place in memory, the
current logic for allocating a kprobes insn_page does not work. The
GFP_DMA allocated buffer might be more than 2 GB away from the kernel.

Use a static buffer for the insn_page instead.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

With a relocatable kernel that could reside at any place in memory, the
storage size for the SYSCALL and PGM_CHECK handlers needs to be
increased from .long to .quad.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch adds support for building a relocatable kernel with -fPIE.
The kernel will be relocated to 0 early in the boot process.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Allow for userspace to use PCI MIO instructions.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Allow users to disable usage of MIO instructions by specifying pci=nomio
at the kernel command line.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Provide support for PCI I/O instructions that work on mapped IO addresses.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

ISM devices are special in how they access PCI memory space. Provide
wrappers for handling commands to the device. No functional change.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This is a preparation patch for usage of new pci instructions.
No functional change.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Provide a kernel parameter to force the usage of floating interrupts.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Gather statistics to distinguish floating and directed interrupts.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Improve /proc/interrupts on s390 to show statistics for individual
MSI interrupts.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Up until now all interrupts on s390 have been floating. For MSI interrupts
we've used a global summary bit vector (with a bit for each function) and
a per-function interrupt bit vector (with a bit per MSI).

This patch introduces a new IRQ delivery mode: CPU directed interrupts.
In this new mode a per-CPU interrupt bit vector is used (with a bit per
MSI per function). Further it is now possible to direct an IRQ to a
specific CPU so we can finally support IRQ affinity.

If an interrupt can't be delivered because the appointed CPU is occupied
by a hypervisor the interrupt is delivered floating. For this a global
summary bit vector is used (with a bit per CPU).
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Provide the ability to create cachesize aligned interrupt vectors.
These will be used for per-CPU interrupt vectors.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Rename and clarify the usage of the interrupt bit vectors. Also change
the array of the per-function bit vectors to be dynamically allocated.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add an extra parameter for airq handlers to recognize
floating vs. directed interrupts.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Detect the adapter CPU directed interruption facility.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Move everything interrupt related from pci.c to pci_irq.c.
No functional change.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

No users of pr_debug in that file.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

No point to keep that around.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Provide an interface for userspace so it can find out if a machine is
capeable of doing secure boot. The interface is, for example, needed for
zipl so it can find out which file format it can/should write to disk.
Signed-off-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

A kernel loaded via kexec_load cannot be verified. Thus disable kexec_load
systemcall in kernels which where IPLed securely. Use the IMA mechanism to
do so.
Signed-off-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add kernel signature verification to kexec_file. The verification is based
on module signature verification and works with kernel images signed via
scripts/sign-file.
Signed-off-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The leading 64 kB of a kernel image doesn't contain any data needed to boot
the new kernel when it was loaded via kexec_file. Thus kexec_file currently
strips them off before loading the image. Keep the leading 64 kB in order
to be able to pass a ipl_report to the next kernel.
Signed-off-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

s390_image_load and s390_elf_load have the same code to load the different
components. Combine this functionality in one shared function.

While at it move kexec_file_update_kernel into the new function as well.
Signed-off-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Access the parmarea in head.S via a struct instead of individual offsets.

While at it make the fields in the parmarea .quads.
Signed-off-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Omit use of script/bin2c hack. Directly include into assembler file instead.
Signed-off-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The purgatory is compiled into the vmlinux and keept in memory all the time
during runtime. Thus any section not needed to load the purgatory
unnecessarily bloats up its foot print in file- and memorysize. Reduce the
purgatory size by stripping the unneeded sections from the purgatory.

This reduces the purgatories size by ~33%.
Signed-off-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

To register data for the next kernel (command line, oldmem_base, etc.) the
current kernel needs to find the ELF segment that contains head.S. This is
currently done by checking ifor 'phdr->p_paddr == 0'. This works fine for
the current kernel build but in theory the first few pages could be
skipped. Make the detection more robust by checking if the entry point lies
within the segment.
Signed-off-by: NPhilipp Rudo <prudo@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When loading an ELF image via kexec_file the segment alignment is ignored
in the calculation for the load address of the next segment. When there are
multiple segments this can lead to segment overlap and thus load failure.
Signed-off-by: NPhilipp Rudo <prudo@linux.ibm.com>
Fixes: 8be01882 ("s390/kexec_file: Add ELF loader")
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>