For KASAN shadow mappings, switch from physmem_alloc_or_die() to
physmem_alloc() and return INVALID_PHYS_ADDR on allocation failure. This
allows gracefully falling back from large pages to smaller pages (1MB
or 4KB) if the allocation of 2GB size/aligned pages cannot be fulfilled.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Add physmem_alloc() as a variant of physmem_alloc_or_die() that can return
an error instead of triggering a panic on OOM. This allows callers to
implement alternative fallback paths.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
The new name better reflects the function's behavior, emphasizing that
it will terminate execution if allocation fails.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Commit c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address
spaces") introduced a large_allowed() helper that restricts which mapping
modes can use large pages. This change unintentionally prevented KASAN
shadow mappings from using large pages, despite there being no reason
to avoid them. In fact, large pages are preferred for performance.
Since commit d8073dc6bc ("s390/mm: Allow large pages only for aligned
physical addresses"), both can_large_pud() and can_large_pmd() call _pa()
to check if large page physical addresses are aligned. However, _pa()
has a side effect: it allocates memory in POPULATE_KASAN_MAP_SHADOW
mode.
Rename large_allowed() to large_page_mapping_allowed() and add
POPULATE_KASAN_MAP_SHADOW to the allowed list to restore large page
mappings for KASAN shadows.
While large_page_mapping_allowed() isn't strictly necessary with current
mapping modes since disallowed modes either don't map anything or fail
alignment and size checks, keep it for clarity.
Rename _pa() to resolve_pa_may_alloc() for clarity and to emphasize
existing side effect. Rework can_large_pud()/can_large_pmd() to take
the side effect into consideration and actually return physical address
instead of just checking conditions.
Fixes: c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address spaces")
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
The futex operation FUTEX_OP_ANDN is supposed to implement
*(int *)UADDR2 &= ~OPARG;
The s390 implementation just implements an AND instead of ANDN.
Add the missing bitwise not operation to oparg to fix this.
This is broken since nearly 19 years, so it looks like user space is
not making use of this operation.
Fixes: 3363fbdd6f ("[PATCH] s390: futex atomic operations")
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Introduce diag310 and memory topology related subcodes.
Provide memory topology information obtanied from diag310 to userspace
via diag ioctl.
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Provide an optimized arch_test_bit() implementation which makes use of
flag output constraint. This generates slightly better code:
bloat-o-meter:
add/remove: 51/19 grow/shrink: 450/2444 up/down: 25198/-49136 (-23938)
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
The generic bitops implementation is nearly identical to the s390
implementation therefore switch to the generic variant.
This results in a small kernel image size decrease. This is because for
the generic variant the nr parameter for most bitops functions is of
type unsigned int while the s390 variant uses unsigned long.
bloat-o-meter:
add/remove: 670/670 grow/shrink: 167/209 up/down: 21440/-21792 (-352)
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
The inline assembly uses the ahi instruction to decrement and test
whether more than 256 bytes are left for conversion. But the nr
variable passed is of type unsigned long. Therefore use aghi.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reported-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
The current code compares whether the nr argument is less or equal to
zero. As nr is of type unsigned long, this isn't correct. Fix this by just
testing for zero. This is also reported by checkpatch:
unsignedLessThanZero: Checking if unsigned expression 'nr--' is less
than zero.
Reported-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
exrl is present in all machines currently supported, therefore prefer
it over ex. This saves one instruction and doesn't need an additional
register to hold the address of the target instruction.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
exrl is present in all machines currently supported, therefore prefer
it over ex. This saves one instruction and doesn't need an additional
register to hold the address of the target instruction.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
exrl is present in all machines currently supported, therefore prefer
it over ex. This saves one instruction and doesn't need an additional
register to hold the address of the target instruction.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
exrl is present in all machines currently supported, therefore prefer
it over ex. This saves one instruction and doesn't need an additional
register to hold the address of the target instruction.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
While converting to generic mmu_gather with commit 9de7d833e3
("s390/tlb: Convert to generic mmu_gather") __tlb_adjust_range()
is called from pte|pmd|p4d_free_tlb(), but not for pud_free_tlb().
__tlb_adjust_range() adjusts the span of TLB range to be flushed,
but s390 does not make use of it. Thus, this change is only for
consistency.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Instead of distributing the memory allocation and pointer arithmetic to
place slib and sl on the page that is allocated for them over multiple
functions and comments, move both into the same context directly next to
each other, so that the knowledge of how this is done is immediately
visible.
The actual layout in memory doesn't change with this, just the structure
of the code to achieve it.
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
ccw_device_get_ciw() already uses array indices to iterate over the vector
of CIWs, but then switches to pointer arithmetic when returning the one it
found. Change this to make it more consistent.
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Niklas Schnelle says:
===================
This patch series enhances the introspectability of the PCI device
recovery for firmware. Until now when Linux performs recovery in
response to a firmware error report. For example, until now firmware
debug data would have no indication if the recovery was successfull or
if it failed, for example due to KVM pass-through.
Improve on this by reporting recovery status as well as some debug
information such as device driver name and s390dbf/pci_msg/sprintf logs
via the SCLP Write Event Data Action Qualifier 2 (Log Data provided)
mechanism.
===================
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Retrieve electrical power readings for resources in a computing
environment via diag 0x324. diag 0x324 stores the power readings in the
power information block (pib).
Provide power readings from pib via diag324 ioctl interface. diag324
ioctl provides new pib to the user only if the threshold time has passed
since the last call. Otherwise, cache data is returned. When there are
no active readers, cleanup of pib buffer is performed.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Create a misc device /dev/diag to fetch diagnose specific information
from the kernel and provide it to userspace.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
exrl is present in all machines currently supported in the linux
kernel, therefore prefer it over ex. This saves one instruction
and doesn't need an additional register to hold the address of the
target instruction.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
By default page protection definitions like PAGE_RX have the _PAGE_NOEXEC
bit set. For older machines without the instruction execution protection
facility this bit is not allowed to be used in page table entries, and
therefore must be removed.
This is done at a couple of page table walkers, but also at some but not
all page table modification functions like ptep_modify_prot_commit(). Avoid
all of this and change the page, segment and region3 protection definitions
so that the noexec bit is masked out automatically if the instruction
execution-protection facility is not available. This is similar to what
also various other architectures do which had to solve the same problem.
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Remove an outdated comment that is also located at a random place. The
generic statement that read permissions imply execute permissions is
wrong since the instruction execution-protection facility is available.
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Using the newly introduced debug_dump() mechanism add formatted content
of pci_debug_msg_id to the PCI report. The formatting is based on the
existing sprintf format but removes caller pointer and area index and
adds an column header. This will allow the platform to collect this log
data together with hardware errors. This sets the reverse flag such that
the newest log entries get added to the PCI report even if not all debug
log entries fit.
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Co-developed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
In this mode debug_dump() writes the debug log starting at the newest
entry followed by earlier entries. To this end add a debug_prev_entry()
helper analogous to debug_next_entry() a helper to get the latest entry
which is one before the active entry and a helper to iterate either
forward or backward.
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Co-developed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
The debug_dump() function allows to get the content of a debug log and
view pair in a string buffer. One future application of this is to
provide debug logs to the platform to be collected with hardware error
logs during recovery.
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Co-developed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Split the allocation respectively freeing of file_private_info_t out
of open() respectively close(). This will be used in a follow on change
to access to debug views without going through the s390dbf filesystem.
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Contrary to convention debug_next_entry() returns a falsy 0 value if
there are more entries and a truthy 1 value when there are no more
entries. As there is only one caller just reverse this logic to be less
surprising and document the behavior in a kdoc comment. Also replace the
goto with an early return. In the future this allows using it in
a do {} while (debug_next_entry(...)) loop.
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Add a mechanism with which the status of PCI error recovery runs
is reported to the platform. Together with the status supply additional
information that may aid in problem determination.
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Although Kconfig specifies:
config KERNEL_IMAGE_BASE
hex "Kernel image base address"
range 0x100000 0x1FFFFFE0000000 if !KASAN
range 0x100000 0x1BFFFFE0000000 if KASAN
default 0x3FFE0000000 if !KASAN
default 0x7FFFE0000000 if KASAN
Running make defconfig or make debug_defconfig
followed by make kasan.config results in a suboptimal
CONFIG_KERNEL_IMAGE_BASE=0x3FFE0000000. Add
CONFIG_KERNEL_IMAGE_BASE=0x7FFFE0000000 to kasan.config to address that.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Add missing include of <linux/smp.h> in abs_lowcore.h to provide
declarations for get_cpu() and put_cpu() used in the code.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
For consistency, remove the `__bootdata` and `__bootdata_preserved`
section annotations from variable declarations in header files. Section
annotations should be applied to definitions, not declarations. This
change moves the annotations to the variable definitions in the
corresponding source files.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Use __atomic_add_const_and_test() within __preempt_count_dec_and_test().
With this it is possible to decrease preempt_count by one and test if
need_resched is set with one instruction, if the compiler has support for
flag output operand constraints.
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Provide arch_atomic_*_and_test() implementations which make use of flag
output constraints, and allow the compiler to generate slightly better
code.
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
GCC uses the number of lines of an inline assembly to calculate its length
(number of instructions). This has an impact on GCCs inlining decisions.
Therefore remove superfluous new lines from a couple of inline
assemblies, so that their real size is reflected.
Also use an "asm inline" statement for the fpu_lfpc_safe() inline assembly
to enforce that GCC assumes the minimum size for this inline assembly,
since it contains various statements which make it appear much larger than
the resulting code is.
Suggested-by: Juergen Christ <jchrist@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Remove the preempt count implementation for pre MARCH_HAS_Z196_FEATURES
builds. If the kernel is compiled with PREEMPT=n, which is the default for
all distributions, this has close to zero impact in the generated code.
Therefore remove the alternative implementation to keep things simple.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
The s390 preempt_count implementation is more or less a copy of the x86
implementation using different instructions. For clarification how this
works also add all comments from x86 with some minor modifications.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
With commit c8a91c285d ("s390/atomic: move remaining inline assemblies to
atomic_ops.h") all remaining atomic inline assemblies have been moved to
atomic_ops.h.
However the result is inconsistent: the functions in atomic_ops.h are
supposed to be used with integral types like int and long pointers, while
the functions in atomic.h work with atomic types.
This layering got violated with the named commit. Therefore adjust this
now, and also use consistent variable names in atomic_ops.h.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Implement arch_atomic_inc() / arch_atomic_dec() functions which result
in a single instruction if compiled for z196 or newer architectures.
Reduces the kernel image size by ~6K (defconfig):
bloat-o-meter:
add/remove: 0/0 grow/shrink: 12/1005 up/down: 106/-6404 (-6298)
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
