BMC/Intel-BMC/linux.git/arch/mips/Kconfig, branch dev-5.0

MIPS: Loongson: Introduce and use loongson_llsc_mb()

2019-02-04T18:53:34+00:00

On the Loongson-2G/2H/3A/3B there is a hardware flaw that ll/sc and lld/scd is very weak ordering. We should add sync instructions "before each ll/lld" and "at the branch-target between ll/sc" to workaround. Otherwise, this flaw will cause deadlock occasionally (e.g. when doing heavy load test with LTP). Below is the explaination of CPU designer: "For Loongson 3 family, when a memory access instruction (load, store, or prefetch)'s executing occurs between the execution of LL and SC, the success or failure of SC is not predictable. Although programmer would not insert memory access instructions between LL and SC, the memory instructions before LL in program-order, may dynamically executed between the execution of LL/SC, so a memory fence (SYNC) is needed before LL/LLD to avoid this situation. Since Loongson-3A R2 (3A2000), we have improved our hardware design to handle this case. But we later deduce a rarely circumstance that some speculatively executed memory instructions due to branch misprediction between LL/SC still fall into the above case, so a memory fence (SYNC) at branch-target (if its target is not between LL/SC) is needed for Loongson 3A1000, 3B1500, 3A2000 and 3A3000. Our processor is continually evolving and we aim to to remove all these workaround-SYNCs around LL/SC for new-come processor." Here is an example: Both cpu1 and cpu2 simutaneously run atomic_add by 1 on same atomic var, this bug cause both 'sc' run by two cpus (in atomic_add) succeed at same time('sc' return 1), and the variable is only *added by 1*, sometimes, which is wrong and unacceptable(it should be added by 2). Why disable fix-loongson3-llsc in compiler? Because compiler fix will cause problems in kernel's __ex_table section. This patch fix all the cases in kernel, but: +. the fix at the end of futex_atomic_cmpxchg_inatomic is for branch-target of 'bne', there other cases which smp_mb__before_llsc() and smp_llsc_mb() fix the ll and branch-target coincidently such as atomic_sub_if_positive/ cmpxchg/xchg, just like this one. +. Loongson 3 does support CONFIG_EDAC_ATOMIC_SCRUB, so no need to touch edac.h +. local_ops and cmpxchg_local should not be affected by this bug since only the owner can write. +. mips_atomic_set for syscall.c is deprecated and rarely used, just let it go Signed-off-by: Huacai Chen Signed-off-by: Huang Pei [paul.burton@mips.com: - Simplify the addition of -mno-fix-loongson3-llsc to cflags, and add a comment describing why it's there. - Make loongson_llsc_mb() a no-op when CONFIG_CPU_LOONGSON3_WORKAROUNDS=n, rather than a compiler memory barrier. - Add a comment describing the bug & how loongson_llsc_mb() helps in asm/barrier.h.] Signed-off-by: Paul Burton Cc: Ralf Baechle Cc: ambrosehua@gmail.com Cc: Steven J . Hill Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang Cc: Zhangjin Wu Cc: Li Xuefeng Cc: Xu Chenghua

mips: fix n32 compat_ipc_parse_version

2019-01-11T19:23:58+00:00

While reading through the sysvipc implementation, I noticed that the n32 semctl/shmctl/msgctl system calls behave differently based on whether o32 support is enabled or not: Without o32, the IPC_64 flag passed by user space is rejected but calls without that flag get IPC_64 behavior. As far as I can tell, this was inadvertently changed by a cleanup patch but never noticed by anyone, possibly nobody has tried using sysvipc on n32 after linux-3.19. Change it back to the old behavior now. Fixes: 78aaf956ba3a ("MIPS: Compat: Fix build error if CONFIG_MIPS32_COMPAT but no compat ABI.") Signed-off-by: Arnd Bergmann Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: stable@vger.kernel.org # 3.19+

Merge tag 'kconfig-v4.21-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2018-12-29T21:40:29+00:00

Pull Kconfig file consolidation from Masahiro Yamada: "Consolidation of bus (PCI, PCMCIA, EISA, RapidIO) config entries by Christoph Hellwig. Currently, every architecture that wants to provide common peripheral busses needs to add some boilerplate code and include the right Kconfig files. This series instead just selects the presence (when needed) and then handles everything in the bus-specific Kconfig file under drivers/" * tag 'kconfig-v4.21-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: pcmcia: remove per-arch PCMCIA config entry eisa: consolidate EISA Kconfig entry in drivers/eisa rapidio: consolidate RAPIDIO config entry in drivers/rapidio pcmcia: allow PCMCIA support independent of the architecture PCI: consolidate the PCI_SYSCALL symbol PCI: consolidate the PCI_DOMAINS and PCI_DOMAINS_GENERIC config options PCI: consolidate PCI config entry in drivers/pci MIPS: remove the HT_PCI config option

Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping

2018-12-28T22:12:21+00:00

Pull DMA mapping updates from Christoph Hellwig: "A huge update this time, but a lot of that is just consolidating or removing code: - provide a common DMA_MAPPING_ERROR definition and avoid indirect calls for dma_map_* error checking - use direct calls for the DMA direct mapping case, avoiding huge retpoline overhead for high performance workloads - merge the swiotlb dma_map_ops into dma-direct - provide a generic remapping DMA consistent allocator for architectures that have devices that perform DMA that is not cache coherent. Based on the existing arm64 implementation and also used for csky now. - improve the dma-debug infrastructure, including dynamic allocation of entries (Robin Murphy) - default to providing chaining scatterlist everywhere, with opt-outs for the few architectures (alpha, parisc, most arm32 variants) that can't cope with it - misc sparc32 dma-related cleanups - remove the dma_mark_clean arch hook used by swiotlb on ia64 and replace it with the generic noncoherent infrastructure - fix the return type of dma_set_max_seg_size (Niklas Söderlund) - move the dummy dma ops for not DMA capable devices from arm64 to common code (Robin Murphy) - ensure dma_alloc_coherent returns zeroed memory to avoid kernel data leaks through userspace. We already did this for most common architectures, but this ensures we do it everywhere. dma_zalloc_coherent has been deprecated and can hopefully be removed after -rc1 with a coccinelle script" * tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping: (73 commits) dma-mapping: fix inverted logic in dma_supported dma-mapping: deprecate dma_zalloc_coherent dma-mapping: zero memory returned from dma_alloc_* sparc/iommu: fix ->map_sg return value sparc/io-unit: fix ->map_sg return value arm64: default to the direct mapping in get_arch_dma_ops PCI: Remove unused attr variable in pci_dma_configure ia64: only select ARCH_HAS_DMA_COHERENT_TO_PFN if swiotlb is enabled dma-mapping: bypass indirect calls for dma-direct vmd: use the proper dma_* APIs instead of direct methods calls dma-direct: merge swiotlb_dma_ops into the dma_direct code dma-direct: use dma_direct_map_page to implement dma_direct_map_sg dma-direct: improve addressability error reporting swiotlb: remove dma_mark_clean swiotlb: remove SWIOTLB_MAP_ERROR ACPI / scan: Refactor _CCA enforcement dma-mapping: factor out dummy DMA ops dma-mapping: always build the direct mapping code dma-mapping: move dma_cache_sync out of line dma-mapping: move various slow path functions out of line ...

dma-mapping: always build the direct mapping code

2018-12-13T20:06:11+00:00

All architectures except for sparc64 use the dma-direct code in some form, and even for sparc64 we had the discussion of a direct mapping mode a while ago. In preparation for directly calling the direct mapping code don't bother having it optionally but always build the code in. This is a minor hardship for some powerpc and arm configs that don't pull it in yet (although they should in a relase ot two), and sparc64 which currently doesn't need it at all, but it will reduce the ifdef mess we'd otherwise need significantly. Signed-off-by: Christoph Hellwig Acked-by: Jesper Dangaard Brouer Tested-by: Jesper Dangaard Brouer Tested-by: Tony Luck

eisa: consolidate EISA Kconfig entry in drivers/eisa

2018-11-23T02:46:22+00:00

Let architectures opt into EISA support by selecting HAVE_EISA and handle everything else in drivers/eisa. Signed-off-by: Christoph Hellwig Acked-by: Thomas Gleixner Acked-by: Paul Burton Signed-off-by: Masahiro Yamada

rapidio: consolidate RAPIDIO config entry in drivers/rapidio

2018-11-23T02:46:13+00:00

There is no good reason to duplicate the RAPIDIO menu in various architectures. Instead provide a selectable HAVE_RAPIDIO symbol that indicates native availability of RAPIDIO support and the handle the rest in drivers/pci. This also means we now provide support for PCI(e) to Rapidio bridges for every architecture instead of a limited subset. Signed-off-by: Christoph Hellwig Acked-by: Thomas Gleixner Acked-by: Paul Burton Signed-off-by: Masahiro Yamada

pcmcia: allow PCMCIA support independent of the architecture

2018-11-23T02:46:00+00:00

There is nothing architecture specific in the PCMCIA core, so allow building it everywhere. The actual host controllers will depend on ISA, PCI or a specific SOC. Signed-off-by: Christoph Hellwig Acked-by: Dominik Brodowski Acked-by: Thomas Gleixner Acked-by: Paul Burton Signed-off-by: Masahiro Yamada

PCI: consolidate the PCI_DOMAINS and PCI_DOMAINS_GENERIC config options

2018-11-23T02:45:44+00:00

Move the definitions to drivers/pci and let the architectures select them. Two small differences to before: PCI_DOMAINS_GENERIC now selects PCI_DOMAINS, cutting down the churn for modern architectures. As the only architectured arm did previously also offer PCI_DOMAINS as a user visible choice in addition to selecting it from the relevant configs, this is gone now. Signed-off-by: Christoph Hellwig Acked-by: Paul Burton Signed-off-by: Masahiro Yamada

PCI: consolidate PCI config entry in drivers/pci

2018-11-23T02:45:34+00:00

There is no good reason to duplicate the PCI menu in every architecture. Instead provide a selectable HAVE_PCI symbol that indicates availability of PCI support, and a FORCE_PCI symbol to for PCI on and the handle the rest in drivers/pci. Signed-off-by: Christoph Hellwig Reviewed-by: Palmer Dabbelt Acked-by: Max Filippov Acked-by: Thomas Gleixner Acked-by: Bjorn Helgaas Acked-by: Geert Uytterhoeven Acked-by: Paul Burton Signed-off-by: Masahiro Yamada