- 03 Aug, 2021 1 commit
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Ilya Leoshkevich authored
Implementing live patching on s390 requires each function's prologue to contain a very special kind of nop, which gcc and clang don't generate. However, the current code assumes that if CC_USING_NOP_MCOUNT is defined, then whatever the compiler generates is good enough. Move the CC_USING_NOP_MCOUNT check into the new ftrace_need_init_nop() macro, that the architectures can override. An alternative solution is to disable using -mnop-mcount in the Makefile, however, this makes the build logic (even) more complicated and forces the arch-specific code to deal with the useless __fentry__ symbol. Signed-off-by:
Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20210728212546.128248-2-iii@linux.ibm.comSigned-off-by:
Heiko Carstens <hca@linux.ibm.com>
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- 30 Jul, 2021 8 commits
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Masahiro Yamada authored
Currently, the install target in arch/s390/Makefile descends into arch/s390/boot/Makefile to invoke the shell script, but there is no good reason to do so. arch/s390/Makefile can run the shell script directly. Signed-off-by:
Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20210729142338.446002-1-masahiroy@kernel.orgSigned-off-by:
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Ilya Leoshkevich authored
s390x GCC and SystemZ Clang have ThreadSanitizer support now [1] [2], so enable KCSAN for s390. [1] https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ea22954e7c58 [2] https://reviews.llvm.org/D105629Signed-off-by:
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Heiko Carstens authored
cycles_t has a different type across architectures: unsigned int, unsinged long, or unsigned long long. Depending on architecture this will generate this warning: kernel/kcsan/debugfs.c: In function ‘microbenchmark’: ./include/linux/kern_levels.h:5:25: warning: format ‘%llu’ expects argument of type ‘long long unsigned int’, but argument 3 has type ‘cycles_t’ {aka ‘long unsigned int’} [-Wformat=] To avoid this simply change the type of cycle to u64 in microbenchmark(), since u64 is of type unsigned long long for all architectures. Acked-by:Marco Elver <elver@google.com> Link: https://lore.kernel.org/r/20210729142811.1309391-1-hca@linux.ibm.comSigned-off-by:
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Sven Schnelle authored
Signed-off-by:
Sven Schnelle <svens@linux.ibm.com> Link: https://lore.kernel.org/r/20210728190254.3921642-5-hca@linux.ibm.comSigned-off-by:
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Sven Schnelle authored
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Sven Schnelle authored
s390 only reports the page address during a translation fault. To make the kfence unit tests pass, add a function that might be implemented by architectures to mask out address bits. Signed-off-by:
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Heiko Carstens authored
Implement set_memory_4k() which will split any present large or huge mapping in the given range to a 4k mapping. Link: https://lore.kernel.org/r/20210728190254.3921642-2-hca@linux.ibm.comSigned-off-by:
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Marco Elver authored
x86's <asm/tlbflush.h> only declares non-module accessible functions (such as flush_tlb_one_kernel) if !MODULE. In preparation of including <asm/kfence.h> from the KFENCE test module, only define the helpers if !MODULE to avoid breaking the build with CONFIG_KFENCE_KUNIT_TEST=m. Signed-off-by:
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- 27 Jul, 2021 31 commits
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Heiko Carstens authored
After all the changes to delay.c there are many includes which are not needed anymore. Get rid of them. Signed-off-by: -
Heiko Carstens authored
sparse warning: CHECK arch/s390/boot/startup.c arch/s390/boot/startup.c:283:39: error: arithmetics on pointers to functions Signed-off-by: -
Ilya Leoshkevich authored
struct brace should be on the same line. Signed-off-by:
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Heiko Carstens authored
Commit 7f16d7e7 ("s390: show virtualization support in /proc/cpuinfo") introduced special handling for sie capability, saying this should not be exposed via hwcaps, without giving a reason. However this leads to an inconsistent /proc/cpuinfo features line where all features except the sie capability are also present in hwcaps. I really don't see a reason to not add that to hwcaps - it might be quite pointless, but at least this way it is possible to get rid of some special handling. Signed-off-by:
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Heiko Carstens authored
Remove the not so obvious "(elf_hwcap & (1UL << 2)" which only checks if stfle is available. This used to be required for old code before test_facility() was introduced. test_facility() will do the right thing, regardless if stfle is available or not. Signed-off-by: -
Heiko Carstens authored
Remove a leftover from the common 31/64 bit code. z/Architecture mode is now always active, there is no need to check. Signed-off-by: -
Heiko Carstens authored
Use a consistent coding style within setup_hwcaps() and remove obvious and outdated comments. Signed-off-by: -
Heiko Carstens authored
The first six hwcap bits are initialized in a rather odd way: an array contains the stfl(e) bits which need to be set, so that the corresponding bit position (= array index) within hwcaps are set. Better open code it like it is done for all other bits, making it obvious which bit is set when. Signed-off-by: -
Heiko Carstens authored
setup_hwcaps() is a quite large function. Make it smaller by moving the elf platform setup code into an independent setup function. Signed-off-by: -
Heiko Carstens authored
Move setup_hwcaps() to processor.c for two reasons: - make setup.c a bit smaller - have allmost all of the hwcap code in one file Signed-off-by: -
Heiko Carstens authored
Add BUILD_BUG_ON() sanity checks to make sure the hwcap string array contains a string for each hwcap. Signed-off-by: -
Heiko Carstens authored
Use named initializers to make it obvious which hwcap string array element belongs to which hwcap. Signed-off-by: -
Heiko Carstens authored
Introduce HWCAP bit numbers, making it easier to tell at which bit number we currently are. Also use these bits with the BIT macro to define the real HWCAP masks. Signed-off-by: -
Heiko Carstens authored
Remove s390 part of all HWCAP defines, just to make them shorter and easier to handle. The namespace is anyway per architecture. This is similar to what arm64 has. Signed-off-by: -
Niklas Schnelle authored
In order to support the use of enhanced PCI instructions in both kernel- and userspace we need both hardware support and proper setup in the kernel. The latter can be toggled off with the pci=nomio command line option. Thus availability of this feature in userspace depends on all of kernel configuration (CONFIG_PCI), hardware support and the current kernel command line and can thus not rely solely on a facility bit. Instead let's introduce a new ELF hardware capability bit HWCAP_S390_PCI_MIO to tell userspace whether these PCI instructions can be used. Reviewed-by:
Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by:
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Niklas Schnelle authored
Kernel support for the newer PCI mio instructions can be toggled off with the pci=nomio command line option which needs to integrate with common code PCI option parsing. However this option then toggles static branches which can't be toggled yet in an early_param() call. Thus commit 9964f396 ("s390: fix setting of mio addressing control") moved toggling the static branches to the PCI init routine. With this setup however we can't check for mio support outside the PCI code during early boot, i.e. before switching the static branches, which we need to be able to export this as an ELF HWCAP. Improve on this by turning mio availability into a machine flag that gets initially set based on CONFIG_PCI and the facility bit and gets toggled off if pci=nomio is found during PCI option parsing allowing simple access to this machine flag after early init. Reviewed-by:
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Heiko Carstens authored
Add more instructions to the kernel disassembler. Signed-off-by: -
Heiko Carstens authored
Add hardware capability bits and feature tags to /proc/cpuinfo for NNPA and Vector-Packed-Decimal-Enhancement Facility 2. Signed-off-by: -
Julian Wiedmann authored
These macros haven't seen any use in a long time. Also note that the queue_irqs_*() ones wouldn't even compile anymore. Signed-off-by:
Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by:
Benjamin Block <bblock@linux.ibm.com> Signed-off-by:
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Julian Wiedmann authored
Now that all drivers use qdio_inspect_queue() and qdio's internal queue tasklets are gone, the driver-specified queue handlers are only called for async error reporting (eg. for an error condition in the QEBSM code). So take a moment to clean up the Output Queue handlers (they are _always_ called with qdio_error != 0), and clarify which error types can be reported through what interface. As Benjamin already suggested a while ago, we should turn these into distinct enums at some point. Signed-off-by:
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Julian Wiedmann authored
get_outbound_buffer_frontier() is only reached via qdio_inspect_queue(), and there we already call qdio_siga_sync_q() unconditionally. Signed-off-by:
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Julian Wiedmann authored
Both qdio drivers have moved away from using qdio's internal tasklet and timer mechanisms for Output Queues. Rip out all the leftovers. Signed-off-by:
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Julian Wiedmann authored
If qdio_cancel_ccw() times out (or is interrupted) before the interrupt for the {halt,clear} action arrives, report this back to the caller as an error. Signed-off-by: -
Julian Wiedmann authored
If the ESTABLISH ccw fails (ie. the qdio_irq is set to QDIO_IRQ_STATE_ERR), we don't need to call qdio_shutdown() for rolling back our earlier actions. All the needed logic is already available in qdio_establish()'s error chain, and using it means we don't have to temporarily drop the setup_mutex either. This makes qdio_shutdown() a purely external function, that should only be called by the driver if an earlier qdio_establish() succeeded. Signed-off-by:
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Julian Wiedmann authored
When the ESTABLISH ccw does not complete within the specified timeout, try our best to cancel the ccw program that is still active on the device. Otherwise the IO subsystem might be accessing it even after the driver eg. called qdio_free(). Fixes: 779e6e1c ("[S390] qdio: new qdio driver.") Signed-off-by:
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Julian Wiedmann authored
When qdio_establish() times out while waiting for the ESTABLISH ccw to complete, it calls qdio_shutdown() to roll back all of its previous actions. But at this point the qdio_irq's state is still QDIO_IRQ_STATE_INACTIVE, so qdio_shutdown() will exit immediately without doing any actual work. Which means that eg. the qdio_irq's thinint-indicator stays registered, and cdev->handler isn't restored to its old value. And since commit 954d6235 ("s390/qdio: make thinint registration symmetric") the qdio_irq also stays on the tiq_list, so on the next qdio_establish() we might get a helpful BUG from the list-debugging code: ... [ 4633.512591] list_add double add: new=00000000005a4110, prev=00000001b357db78, next=00000000005a4110. [ 4633.512621] ------------[ cut here ]------------ [ 4633.512623] kernel BUG at lib/list_debug.c:29! ... [ 4633.512796] [<00000001b2c6ee9a>] __list_add_valid+0x82/0xa0 [ 4633.512798] ([<00000001b2c6ee96>] __list_add_valid+0x7e/0xa0) [ 4633.512800] [<00000001b2fcecce>] qdio_establish_thinint+0x116/0x190 [ 4633.512805] [<00000001b2fcbe58>] qdio_establish+0x128/0x498 ... Fix this by extracting a goto-chain from the existing error exits in qdio_establish(), and check the return value of the wait_event_...() to detect the timeout condition. Fixes: 779e6e1c ("[S390] qdio: new qdio driver.") Root-caused-by:
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Alexander Egorenkov authored
There is no useful information within [STARTUP_NORMAL_OFFSET, HEAD_END] now. But the memory region [0, STARTUP_NORMAL_OFFSET] is used by: * lowcore * kdump for swapping memory * stand-alone zipl dumpers for code, data, stack and heap Signed-off-by:
Alexander Egorenkov <egorenar@linux.ibm.com> Acked-by:
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Alexander Egorenkov authored
This change simplifies the task of making the decompressor relocatable. The decompressor's image contains special DMA sections between _sdma and _edma. This DMA segment is loaded at boot as part of the decompressor and then simply handed over to the decompressed kernel. The decompressor itself never uses it in any way. The primary reason for this is the need to keep the aforementioned DMA segment below 2GB which is required by architecture, and because the decompressor is always loaded at a fixed low physical address, it is guaranteed that the DMA region will not cross the 2GB memory limit. If the DMA region had been placed in the decompressed kernel, then KASLR would make this guarantee impossible to fulfill or it would be restricted to the first 2GB of memory address space. This commit moves all DMA sections between _sdma and _edma from the decompressor's image to the decompressed kernel's image. The complete DMA region is placed in the init section of the decompressed kernel and immediately relocated below 2GB at start-up before it is needed by other parts of the decompressed kernel. The relocation of the DMA region happens even if the decompressed kernel is already located below 2GB in order to keep the first implementation simple. The relocation should not have any noticeable impact on boot time because the DMA segment is only a couple of pages. After relocating the DMA sections, the kernel has to fix all references which point into it. In order to automate this, place all variables pointing into the DMA sections in a special .dma.refs section. All such variables must be defined using the new __dma_ref macro. Only variables containing addresses within the DMA sections must be placed in the new .dma.refs section. Furthermore, move the initialization of control registers from the decompressor to the decompressed kernel because some control registers reference tables that must be placed in the DMA data section to guarantee that their addresses are below 2G. Because the decompressed kernel relocates the DMA sections at startup, the content of control registers CR2, CR5 and CR15 must be updated with new addresses after the relocation. The decompressed kernel initializes all control registers early at boot and then updates the content of CR2, CR5 and CR15 as soon as the DMA relocation has occurred. This practically reverts the commit a80313ff ("s390/kernel: introduce .dma sections"). Signed-off-by:
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Heiko Carstens authored
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Alexander Egorenkov authored
As a preparation for moving the .dma.data section from the decompressor to the decompressed kernel, the .dma.data section must be made relocatable by replacing absolute memory addressing with relative one. This is required in order to be able to relocate the DMA section to a memory address <= 2G as required by the hardware architecture. The DMA section must be relocated in case the decompressed kernel was loaded to an address >= 2G which can occur if KASAN is enabled. By making the whole DMA section position-independent we avoid applying relocations to it whenever it is moved to a different address, which becomes possible as soon as it becomes a part of the decompressed kernel. Signed-off-by:
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Alexander Egorenkov authored
Both macros are used only in decompressor's head.S, unnecessary to put them in a global header used in many places like setup.h is. Signed-off-by:
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