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2019-03-27MIPS: Fix kernel crash for R6 in jump label branch functionArcher Yan1-4/+4
commit 47c25036b60f27b86ab44b66a8861bcf81cde39b upstream. Insert Branch instruction instead of NOP to make sure assembler don't patch code in forbidden slot. In jump label function, it might be possible to patch Control Transfer Instructions(CTIs) into forbidden slot, which will generate Reserved Instruction exception in MIPS release 6. Signed-off-by: Archer Yan <ayan@wavecomp.com> Reviewed-by: Paul Burton <paul.burton@mips.com> [paul.burton@mips.com: - Add MIPS prefix to subject. - Mark for stable from v4.0, which introduced r6 support, onwards.] Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: linux-mips@vger.kernel.org Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23KVM: Call kvm_arch_memslots_updated() before updating memslotsSean Christopherson1-1/+1
commit 152482580a1b0accb60676063a1ac57b2d12daf6 upstream. kvm_arch_memslots_updated() is at this point in time an x86-specific hook for handling MMIO generation wraparound. x86 stashes 19 bits of the memslots generation number in its MMIO sptes in order to avoid full page fault walks for repeat faults on emulated MMIO addresses. Because only 19 bits are used, wrapping the MMIO generation number is possible, if unlikely. kvm_arch_memslots_updated() alerts x86 that the generation has changed so that it can invalidate all MMIO sptes in case the effective MMIO generation has wrapped so as to avoid using a stale spte, e.g. a (very) old spte that was created with generation==0. Given that the purpose of kvm_arch_memslots_updated() is to prevent consuming stale entries, it needs to be called before the new generation is propagated to memslots. Invalidating the MMIO sptes after updating memslots means that there is a window where a vCPU could dereference the new memslots generation, e.g. 0, and incorrectly reuse an old MMIO spte that was created with (pre-wrap) generation==0. Fixes: e59dbe09f8e6 ("KVM: Introduce kvm_arch_memslots_updated()") Cc: <stable@vger.kernel.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12mmc: jz4740: Get CD/WP GPIOs from descriptorsLinus Walleij1-2/+0
[ Upstream commit 0c901c0566fb4edc2631c3786e5085a037be91f8 ] Modifty the JZ4740 driver to retrieve card detect and write protect GPIO pins from GPIO descriptors instead of hard-coded global numbers. Augment the only board file using this in the process and cut down on passed in platform data. Preserve the code setting the caps2 flags for CD and WP as active low or high since the slot GPIO code currently ignores the gpiolib polarity inversion semantice and uses the raw accessors to read the GPIO lines, but set the right polarity flags in the descriptor table for jz4740. Cc: Paul Cercueil <paul@crapouillou.net> Cc: linux-mips@linux-mips.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Paul Burton <paul.burton@mips.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-12mips: bpf: fix encoding bug for mm_srlv32_opJiong Wang1-1/+1
[ Upstream commit 17f6c83fb5ebf7db4fcc94a5be4c22d5a7bfe428 ] For micro-mips, srlv inside POOL32A encoding space should use 0x50 sub-opcode, NOT 0x90. Some early version ISA doc describes the encoding as 0x90 for both srlv and srav, this looks to me was a typo. I checked Binutils libopcode implementation which is using 0x50 for srlv and 0x90 for srav. v1->v2: - Keep mm_srlv32_op sorted by value. Fixes: f31318fdf324 ("MIPS: uasm: Add srlv uasm instruction") Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Paul Burton <paul.burton@mips.com> Cc: linux-mips@vger.kernel.org Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-09MIPS: Only include mmzone.h when CONFIG_NEED_MULTIPLE_NODES=yPaul Burton2-3/+4
commit 66a4059ba72c23ae74a7c702894ff76c4b7eac1f upstream. MIPS' asm/mmzone.h includes the machine/platform mmzone.h unconditionally, but since commit bb53fdf395ee ("MIPS: c-r4k: Add r4k_blast_scache_node for Loongson-3") is included by asm/rk4cache.h for all r4k-style configs regardless of CONFIG_NEED_MULTIPLE_NODES. This is problematic when CONFIG_NEED_MULTIPLE_NODES=n because both the loongson3 & ip27 mmzone.h headers unconditionally define the NODE_DATA preprocessor macro which is aready defined by linux/mmzone.h, resulting in the following build error: In file included from ./arch/mips/include/asm/mmzone.h:10, from ./arch/mips/include/asm/r4kcache.h:23, from arch/mips/mm/c-r4k.c:33: ./arch/mips/include/asm/mach-loongson64/mmzone.h:48: error: "NODE_DATA" redefined [-Werror] #define NODE_DATA(n) (&__node_data[(n)]->pglist) In file included from ./include/linux/topology.h:32, from ./include/linux/irq.h:19, from ./include/asm-generic/hardirq.h:13, from ./arch/mips/include/asm/hardirq.h:16, from ./include/linux/hardirq.h:9, from arch/mips/mm/c-r4k.c:11: ./include/linux/mmzone.h:907: note: this is the location of the previous definition #define NODE_DATA(nid) (&contig_page_data) Resolve this by only including the machine mmzone.h when CONFIG_NEED_MULTIPLE_NODES=y, which also removes the need for the empty mach-generic version of the header which we delete. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: bb53fdf395ee ("MIPS: c-r4k: Add r4k_blast_scache_node for Loongson-3") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09MIPS: Fix a R10000_LLSC_WAR logic in atomic.hHuacai Chen1-1/+1
commit db1ce3f5d01d2d6d5714aefba0159d2cb5167a0b upstream. Commit 4936084c2ee2 ("MIPS: Cleanup R10000_LLSC_WAR logic in atomic.h") introduce a mistake in atomic64_fetch_##op##_relaxed(), because it forget to delete R10000_LLSC_WAR in the if-condition. So fix it. Fixes: 4936084c2ee2 ("MIPS: Cleanup R10000_LLSC_WAR logic in atomic.h") Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Steven J . Hill <Steven.Hill@cavium.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # 4.19+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09MIPS: Expand MIPS32 ASIDs to 64 bitsPaul Burton3-8/+6
commit ff4dd232ec45a0e45ea69f28f069f2ab22b4908a upstream. ASIDs have always been stored as unsigned longs, ie. 32 bits on MIPS32 kernels. This is problematic because it is feasible for the ASID version to overflow & wrap around to zero. We currently attempt to handle this overflow by simply setting the ASID version to 1, using asid_first_version(), but we make no attempt to account for the fact that there may be mm_structs with stale ASIDs that have versions which we now reuse due to the overflow & wrap around. Encountering this requires that: 1) A struct mm_struct X is active on CPU A using ASID (V,n). 2) That mm is not used on CPU A for the length of time that it takes for CPU A's asid_cache to overflow & wrap around to the same version V that the mm had in step 1. During this time tasks using the mm could either be sleeping or only scheduled on other CPUs. 3) Some other mm Y becomes active on CPU A and is allocated the same ASID (V,n). 4) mm X now becomes active on CPU A again, and now incorrectly has the same ASID as mm Y. Where struct mm_struct ASIDs are represented above in the format (version, EntryHi.ASID), and on a typical MIPS32 system version will be 24 bits wide & EntryHi.ASID will be 8 bits wide. The length of time required in step 2 is highly dependent upon the CPU & workload, but for a hypothetical 2GHz CPU running a workload which generates a new ASID every 10000 cycles this period is around 248 days. Due to this long period of time & the fact that tasks need to be scheduled in just the right (or wrong, depending upon your inclination) way, this is obviously a difficult bug to encounter but it's entirely possible as evidenced by reports. In order to fix this, simply extend ASIDs to 64 bits even on MIPS32 builds. This will extend the period of time required for the hypothetical system above to encounter the problem from 28 days to around 3 trillion years, which feels safely outside of the realms of possibility. The cost of this is slightly more generated code in some commonly executed paths, but this is pretty minimal: | Code Size Gain | Percentage -----------------------|----------------|------------- decstation_defconfig | +270 | +0.00% 32r2el_defconfig | +652 | +0.01% 32r6el_defconfig | +1000 | +0.01% I have been unable to measure any change in performance of the LMbench lat_ctx or lat_proc tests resulting from the 64b ASIDs on either 32r2el_defconfig+interAptiv or 32r6el_defconfig+I6500 systems. Signed-off-by: Paul Burton <paul.burton@mips.com> Suggested-by: James Hogan <jhogan@kernel.org> References: https://lore.kernel.org/linux-mips/80B78A8B8FEE6145A87579E8435D78C30205D5F3@fzex.ruijie.com.cn/ References: https://lore.kernel.org/linux-mips/1488684260-18867-1-git-send-email-jiwei.sun@windriver.com/ Cc: Jiwei Sun <jiwei.sun@windriver.com> Cc: Yu Huabing <yhb@ruijie.com.cn> Cc: stable@vger.kernel.org # 2.6.12+ Cc: linux-mips@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09MIPS: Ensure pmd_present() returns false after pmd_mknotpresent()Huacai Chen1-0/+5
commit 92aa0718c9fa5160ad2f0e7b5bffb52f1ea1e51a upstream. This patch is borrowed from ARM64 to ensure pmd_present() returns false after pmd_mknotpresent(). This is needed for THP. References: 5bb1cc0ff9a6 ("arm64: Ensure pmd_present() returns false after pmd_mknotpresent()") Reviewed-by: James Hogan <jhogan@kernel.org> Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/21135/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <james.hogan@mips.com> Cc: Steven J . Hill <Steven.Hill@cavium.com> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: <stable@vger.kernel.org> # 3.8+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09MIPS: c-r4k: Add r4k_blast_scache_node for Loongson-3Huacai Chen4-0/+33
commit bb53fdf395eed103f85061bfff3b116cee123895 upstream. For multi-node Loongson-3 (NUMA configuration), r4k_blast_scache() can only flush Node-0's scache. So we add r4k_blast_scache_node() by using (CAC_BASE | (node_id << NODE_ADDRSPACE_SHIFT)) instead of CKSEG0 as the start address. Signed-off-by: Huacai Chen <chenhc@lemote.com> [paul.burton@mips.com: Include asm/mmzone.h from asm/r4kcache.h for nid_to_addrbase(). Add asm/mach-generic/mmzone.h to allow inclusion for all platforms.] Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/21129/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <james.hogan@mips.com> Cc: Steven J . Hill <Steven.Hill@cavium.com> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: <stable@vger.kernel.org> # 3.15+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-08mips: fix mips_get_syscall_arg o32 checkDmitry V. Levin1-1/+1
commit c50cbd85cd7027d32ac5945bb60217936b4f7eaf upstream. When checking for TIF_32BIT_REGS flag, mips_get_syscall_arg() should use the task specified as its argument instead of the current task. This potentially affects all syscall_get_arguments() users who specify tasks different from the current. Fixes: c0ff3c53d4f99 ("MIPS: Enable HAVE_ARCH_TRACEHOOK.") Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/21185/ Cc: Elvira Khabirova <lineprinter@altlinux.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.13+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21MIPS: Loongson-3: Fix BRIDGE irq delivery problemHuacai Chen1-1/+1
[ Upstream commit 360fe725f8849aaddc53475fef5d4a0c439b05ae ] After commit e509bd7da149dc349160 ("genirq: Allow migration of chained interrupts by installing default action") Loongson-3 fails at here: setup_irq(LOONGSON_HT1_IRQ, &cascade_irqaction); This is because both chained_action and cascade_irqaction don't have IRQF_SHARED flag. This will cause Loongson-3 resume fails because HPET timer interrupt can't be delivered during S3. So we set the irqchip of the chained irq to loongson_irq_chip which doesn't disable the chained irq in CP0.Status. Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/20434/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: Huacai Chen <chenhuacai@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-13MIPS: VDSO: Reduce VDSO_RANDOMIZE_SIZE to 64MB for 64bitHuacai Chen1-1/+1
[ Upstream commit c61c7def1fa0a722610d89790e0255b74f3c07dd ] Commit ea7e0480a4b6 ("MIPS: VDSO: Always map near top of user memory") set VDSO_RANDOMIZE_SIZE to 256MB for 64bit kernel. But take a look at arch/mips/mm/mmap.c we can see that MIN_GAP is 128MB, which means the mmap_base may be at (user_address_top - 128MB). This make the stack be surrounded by mmaped areas, then stack expanding fails and causes a segmentation fault. Therefore, VDSO_RANDOMIZE_SIZE should be less than MIN_GAP and this patch reduce it to 64MB. Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: ea7e0480a4b6 ("MIPS: VDSO: Always map near top of user memory") Patchwork: https://patchwork.linux-mips.org/patch/20910/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: Huacai Chen <chenhuacai@gmail.com> Cc: stable@vger.kernel.org # 4.19 Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-09-28MIPS: VDSO: Always map near top of user memoryPaul Burton1-5/+5
When using the legacy mmap layout, for example triggered using ulimit -s unlimited, get_unmapped_area() fills memory from bottom to top starting from a fairly low address near TASK_UNMAPPED_BASE. This placement is suboptimal if the user application wishes to allocate large amounts of heap memory using the brk syscall. With the VDSO being located low in the user's virtual address space, the amount of space available for access using brk is limited much more than it was prior to the introduction of the VDSO. For example: # ulimit -s unlimited; cat /proc/self/maps 00400000-004ec000 r-xp 00000000 08:00 71436 /usr/bin/coreutils 004fc000-004fd000 rwxp 000ec000 08:00 71436 /usr/bin/coreutils 004fd000-0050f000 rwxp 00000000 00:00 0 00cc3000-00ce4000 rwxp 00000000 00:00 0 [heap] 2ab96000-2ab98000 r--p 00000000 00:00 0 [vvar] 2ab98000-2ab99000 r-xp 00000000 00:00 0 [vdso] 2ab99000-2ab9d000 rwxp 00000000 00:00 0 ... Resolve this by adjusting STACK_TOP to reserve space for the VDSO & providing an address hint to get_unmapped_area() causing it to use this space even when using the legacy mmap layout. We reserve enough space for the VDSO, plus 1MB or 256MB for 32 bit & 64 bit systems respectively within which we randomize the VDSO base address. Previously this randomization was taken care of by the mmap base address randomization performed by arch_mmap_rnd(). The 1MB & 256MB sizes are somewhat arbitrary but chosen such that we have some randomization without taking up too much of the user's virtual address space, which is often in short supply for 32 bit systems. With this the VDSO is always mapped at a high address, leaving lots of space for statically linked programs to make use of brk: # ulimit -s unlimited; cat /proc/self/maps 00400000-004ec000 r-xp 00000000 08:00 71436 /usr/bin/coreutils 004fc000-004fd000 rwxp 000ec000 08:00 71436 /usr/bin/coreutils 004fd000-0050f000 rwxp 00000000 00:00 0 00c28000-00c49000 rwxp 00000000 00:00 0 [heap] ... 7f67c000-7f69d000 rwxp 00000000 00:00 0 [stack] 7f7fc000-7f7fd000 rwxp 00000000 00:00 0 7fcf1000-7fcf3000 r--p 00000000 00:00 0 [vvar] 7fcf3000-7fcf4000 r-xp 00000000 00:00 0 [vdso] Signed-off-by: Paul Burton <paul.burton@mips.com> Reported-by: Huacai Chen <chenhc@lemote.com> Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Cc: Huacai Chen <chenhc@lemote.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v4.4+
2018-09-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds1-0/+1
Pull networking fixes from David Miller: 1) Fix up several Kconfig dependencies in netfilter, from Martin Willi and Florian Westphal. 2) Memory leak in be2net driver, from Petr Oros. 3) Memory leak in E-Switch handling of mlx5 driver, from Raed Salem. 4) mlx5_attach_interface needs to check for errors, from Huy Nguyen. 5) tipc_release() needs to orphan the sock, from Cong Wang. 6) Need to program TxConfig register after TX/RX is enabled in r8169 driver, not beforehand, from Maciej S. Szmigiero. 7) Handle 64K PAGE_SIZE properly in ena driver, from Netanel Belgazal. 8) Fix crash regression in ip_do_fragment(), from Taehee Yoo. 9) syzbot can create conditions where kernel log is flooded with synflood warnings due to creation of many listening sockets, fix that. From Willem de Bruijn. 10) Fix RCU issues in rds socket layer, from Cong Wang. 11) Fix vlan matching in nfp driver, from Pieter Jansen van Vuuren. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (59 commits) nfp: flower: reject tunnel encap with ipv6 outer headers for offloading nfp: flower: fix vlan match by checking both vlan id and vlan pcp tipc: check return value of __tipc_dump_start() s390/qeth: don't dump past end of unknown HW header s390/qeth: use vzalloc for QUERY OAT buffer s390/qeth: switch on SG by default for IQD devices s390/qeth: indicate error when netdev allocation fails rds: fix two RCU related problems r8169: Clear RTL_FLAG_TASK_*_PENDING when clearing RTL_FLAG_TASK_ENABLED erspan: fix error handling for erspan tunnel erspan: return PACKET_REJECT when the appropriate tunnel is not found tcp: rate limit synflood warnings further MIPS: lantiq: dma: add dev pointer netfilter: xt_hashlimit: use s->file instead of s->private netfilter: nfnetlink_queue: Solve the NFQUEUE/conntrack clash for NF_REPEAT netfilter: cttimeout: ctnl_timeout_find_get() returns incorrect pointer to type netfilter: conntrack: timeout interface depend on CONFIG_NF_CONNTRACK_TIMEOUT netfilter: conntrack: reset tcp maxwin on re-register qmi_wwan: Support dynamic config on Quectel EP06 ethernet: renesas: convert to SPDX identifiers ...
2018-09-12MIPS: lantiq: dma: add dev pointerHauke Mehrtens1-0/+1
dma_zalloc_coherent() now crashes if no dev pointer is given. Add a dev pointer to the ltq_dma_channel structure and fill it in the driver using it. This fixes a bug introduced in kernel 4.19. Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-07KVM: Remove obsolete kvm_unmap_hva notifier backendMarc Zyngier1-1/+0
kvm_unmap_hva is long gone, and we only have kvm_unmap_hva_range to deal with. Drop the now obsolete code. Fixes: fb1522e099f0 ("KVM: update to new mmu_notifier semantic v2") Cc: James Hogan <jhogan@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2018-08-24Merge tag 'mips_4.19_2' of ↵Linus Torvalds5-1/+49
git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux Pull MIPS fixes from Paul Burton: - Fix microMIPS build failures by adding a .insn directive to the barrier_before_unreachable() asm statement in order to convince the toolchain that the asm statement is a valid branch target rather than a bogus attempt to switch ISA. - Clean up our declarations of TLB functions that we overwrite with generated code in order to prevent the compiler making assumptions about alignment that cause microMIPS kernels built with GCC 7 & above to die early during boot. - Fix up a regression for MIPS32 kernels which slipped into the main MIPS pull for 4.19, causing CONFIG_32BIT=y kernels to contain inappropriate MIPS64 instructions. - Extend our existing workaround for MIPSr6 builds that end up using the __multi3 intrinsic to GCC 7 & below, rather than just GCC 7. * tag 'mips_4.19_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: MIPS: lib: Provide MIPS64r6 __multi3() for GCC < 7 MIPS: Workaround GCC __builtin_unreachable reordering bug compiler.h: Allow arch-specific asm/compiler.h MIPS: Avoid move psuedo-instruction whilst using MIPS_ISA_LEVEL MIPS: Consistently declare TLB functions MIPS: Export tlbmiss_handler_setup_pgd near its definition
2018-08-21MIPS: Workaround GCC __builtin_unreachable reordering bugPaul Burton1-0/+35
Some versions of GCC for the MIPS architecture suffer from a bug which can lead to instructions from beyond an unreachable statement being incorrectly reordered into earlier branch delay slots if the unreachable statement is the only content of a case in a switch statement. This can lead to seemingly random behaviour, such as invalid memory accesses from incorrectly reordered loads or stores, and link failures on microMIPS builds. See this potential GCC fix for details: https://gcc.gnu.org/ml/gcc-patches/2015-09/msg00360.html Runtime problems resulting from this bug were initially observed using a maltasmvp_defconfig v4.4 kernel built using GCC 4.9.2 (from a Codescape SDK 2015.06-05 toolchain), with the result being an address exception taken after log messages about the L1 caches (during probe of the L2 cache): Initmem setup node 0 [mem 0x0000000080000000-0x000000009fffffff] VPE topology {2,2} total 4 Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes. Primary data cache 64kB, 4-way, PIPT, no aliases, linesize 32 bytes <AdEL exception here> This is early enough that the kernel exception vectors are not in use, so any further output depends upon the bootloader. This is reproducible in QEMU where no further output occurs - ie. the system hangs here. Given the nature of the bug it may potentially be hit with differing symptoms. The bug is known to affect GCC versions as recent as 7.3, and it is unclear whether GCC 8 fixed it or just happens not to encounter the bug in the testcase found at the link above due to differing optimizations. This bug can be worked around by placing a volatile asm statement, which GCC is prevented from reordering past, prior to the __builtin_unreachable call. That was actually done already for other reasons by commit 173a3efd3edb ("bug.h: work around GCC PR82365 in BUG()"), but creates problems for microMIPS builds due to the lack of a .insn directive. The microMIPS ISA allows for interlinking with regular MIPS32 code by repurposing bit 0 of the program counter as an ISA mode bit. To switch modes one changes the value of this bit in the PC. However typical branch instructions encode their offsets as multiples of 2-byte instruction halfwords, which means they cannot change ISA mode - this must be done using either an indirect branch (a jump-register in MIPS terminology) or a dedicated jalx instruction. In order to ensure that regular branches don't attempt to target code in a different ISA which they can't actually switch to, the linker will check that branch targets are code in the same ISA as the branch. Unfortunately our empty asm volatile statements don't qualify as code, and the link for microMIPS builds fails with errors such as: arch/mips/mm/dma-default.s:3265: Error: branch to a symbol in another ISA mode arch/mips/mm/dma-default.s:5027: Error: branch to a symbol in another ISA mode Resolve this by adding a .insn directive within the asm statement which declares that what comes next is code. This may or may not be true, since we don't really know what comes next, but as this code is in an unreachable path anyway that doesn't matter since we won't execute it. We do this in asm/compiler.h & select CONFIG_HAVE_ARCH_COMPILER_H in order to have this included by linux/compiler_types.h after linux/compiler-gcc.h. This will result in asm/compiler.h being included in all C compilations via the -include linux/compiler_types.h argument in c_flags, which should be harmless. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: 173a3efd3edb ("bug.h: work around GCC PR82365 in BUG()") Patchwork: https://patchwork.linux-mips.org/patch/20270/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-mips@linux-mips.org
2018-08-18MIPS: Avoid move psuedo-instruction whilst using MIPS_ISA_LEVELPaul Burton1-1/+3
MIPS_ISA_LEVEL is always defined as the 64 bit ISA that is a compatible superset of the ISA that the kernel build is targeting, and is used to allow us to emit instructions that we may detect support for at runtime. When we use a .set MIPS_ISA_LEVEL directive & are building a 32-bit kernel, we therefore are temporarily allowing the assembler to generate MIPS64 instructions. Using the move pseudo-instruction whilst this is the case is problematic because the assembler is likely to emit a daddu instruction which will generate a reserved instruction exception when executed on a MIPS32 machine. Unfortunately the combination of commit a0a5ac3ce8fe ("MIPS: Fix delay slot bug in `atomic*_sub_if_positive' for R10000_LLSC_WAR") and commit 4936084c2ee2 ("MIPS: Cleanup R10000_LLSC_WAR logic in atomic.h") causes us to do exactly this in atomic_sub_if_positive(), and the result is MIPS64 daddu instructions in 32-bit kernels. Fix this by using .set mips0 to restore the default ISA after the ll instruction, and use .set MIPS_ISA_LEVEL again prior to the sc. This ensures everything but the ll & sc are assembled using the default ISA for the kernel build & the move pseudo-instruction is emitted as a MIPS32 addu instruction. We appear to have another pre-existing instance of the same issue in our atomic_fetch_*_relaxed() functions, and fix that up too by moving our .set move0 such that it occurs prior to use of the move pseudo-instruction. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: a0a5ac3ce8fe ("MIPS: Fix delay slot bug in `atomic*_sub_if_positive' for R10000_LLSC_WAR") Fixes: 4936084c2ee2 ("MIPS: Cleanup R10000_LLSC_WAR logic in atomic.h") Patchwork: https://patchwork.linux-mips.org/patch/20253/ Cc: James Hogan <jhogan@kernel.org> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-08-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds1-0/+3
Pull networking updates from David Miller: "Highlights: - Gustavo A. R. Silva keeps working on the implicit switch fallthru changes. - Support 802.11ax High-Efficiency wireless in cfg80211 et al, From Luca Coelho. - Re-enable ASPM in r8169, from Kai-Heng Feng. - Add virtual XFRM interfaces, which avoids all of the limitations of existing IPSEC tunnels. From Steffen Klassert. - Convert GRO over to use a hash table, so that when we have many flows active we don't traverse a long list during accumluation. - Many new self tests for routing, TC, tunnels, etc. Too many contributors to mention them all, but I'm really happy to keep seeing this stuff. - Hardware timestamping support for dpaa_eth/fsl-fman from Yangbo Lu. - Lots of cleanups and fixes in L2TP code from Guillaume Nault. - Add IPSEC offload support to netdevsim, from Shannon Nelson. - Add support for slotting with non-uniform distribution to netem packet scheduler, from Yousuk Seung. - Add UDP GSO support to mlx5e, from Boris Pismenny. - Support offloading of Team LAG in NFP, from John Hurley. - Allow to configure TX queue selection based upon RX queue, from Amritha Nambiar. - Support ethtool ring size configuration in aquantia, from Anton Mikaev. - Support DSCP and flowlabel per-transport in SCTP, from Xin Long. - Support list based batching and stack traversal of SKBs, this is very exciting work. From Edward Cree. - Busyloop optimizations in vhost_net, from Toshiaki Makita. - Introduce the ETF qdisc, which allows time based transmissions. IGB can offload this in hardware. From Vinicius Costa Gomes. - Add parameter support to devlink, from Moshe Shemesh. - Several multiplication and division optimizations for BPF JIT in nfp driver, from Jiong Wang. - Lots of prepatory work to make more of the packet scheduler layer lockless, when possible, from Vlad Buslov. - Add ACK filter and NAT awareness to sch_cake packet scheduler, from Toke Høiland-Jørgensen. - Support regions and region snapshots in devlink, from Alex Vesker. - Allow to attach XDP programs to both HW and SW at the same time on a given device, with initial support in nfp. From Jakub Kicinski. - Add TLS RX offload and support in mlx5, from Ilya Lesokhin. - Use PHYLIB in r8169 driver, from Heiner Kallweit. - All sorts of changes to support Spectrum 2 in mlxsw driver, from Ido Schimmel. - PTP support in mv88e6xxx DSA driver, from Andrew Lunn. - Make TCP_USER_TIMEOUT socket option more accurate, from Jon Maxwell. - Support for templates in packet scheduler classifier, from Jiri Pirko. - IPV6 support in RDS, from Ka-Cheong Poon. - Native tproxy support in nf_tables, from Máté Eckl. - Maintain IP fragment queue in an rbtree, but optimize properly for in-order frags. From Peter Oskolkov. - Improvde handling of ACKs on hole repairs, from Yuchung Cheng" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1996 commits) bpf: test: fix spelling mistake "REUSEEPORT" -> "REUSEPORT" hv/netvsc: Fix NULL dereference at single queue mode fallback net: filter: mark expected switch fall-through xen-netfront: fix warn message as irq device name has '/' cxgb4: Add new T5 PCI device ids 0x50af and 0x50b0 net: dsa: mv88e6xxx: missing unlock on error path rds: fix building with IPV6=m inet/connection_sock: prefer _THIS_IP_ to current_text_addr net: dsa: mv88e6xxx: bitwise vs logical bug net: sock_diag: Fix spectre v1 gadget in __sock_diag_cmd() ieee802154: hwsim: using right kind of iteration net: hns3: Add vlan filter setting by ethtool command -K net: hns3: Set tx ring' tc info when netdev is up net: hns3: Remove tx ring BD len register in hns3_enet net: hns3: Fix desc num set to default when setting channel net: hns3: Fix for phy link issue when using marvell phy driver net: hns3: Fix for information of phydev lost problem when down/up net: hns3: Fix for command format parsing error in hclge_is_all_function_id_zero net: hns3: Add support for serdes loopback selftest bnxt_en: take coredump_record structure off stack ...
2018-08-14Merge tag 'mtd/for-4.19' of git://git.infradead.org/linux-mtdLinus Torvalds2-64/+0
Pull mtd updates from Boris Brezillon: "JFFS2 changes: - Support 64-bit timestamps MTD core changes: - Support sub-partitions - Clarify mtd_oob_ops documentation - Make Kconfig formatting consistent - Fix potential overflows in mtdchar_{write,read}() - Fallback to ->_{read,write}() when ->_{read,write}_oob() is missing and no OOB data were requested - Remove VLA usage in the bch lib MTD driver changes: - Use mtd_device_register() instead of mtd_device_parse_register() where applicable - Use proper printk format to print physical addresses in the solutionengine driver - Add missing mtd_set_of_node() call in the powernv driver - Remove unneeded variables in a few drivers - Plug the TRX part parser to the DT partition parsers logic - Check ioremap_cache() return code in the gpio-addr-flash driver - Stop using VMLINUX_SYMBOL_STR() in gen_probe.c SPI NOR core changes: - Apply reset hacks only when reset is explicitly marked as broken in the DT SPI NOR driver changes: - Minor cleanup/fixes in the m25p80 driver - Release flash_np in the nxp-spifi driver - Add suspend/resume hooks to the atmel-quadspi driver - Include gpio/consumer.h instead of gpio.h in the atmel-quadspi driver - Use %pK instead of %p in the stm32-quadspi driver - Improve timeout handling in the cadence-quadspi driver - Use mtd_device_register() instead of mtd_device_parse_register() in the intel-spi driver NAND core changes: - Add the SPI-NAND framework. - Create a helper to find the best ECC configuration. - Create NAND controller operations. - Allocate dynamically ONFI parameters structure. - Add defines for ONFI version bits. - Add manufacturer fixup for ONFI parameter page. - Add an option to specify NAND chip as a boot device. - Add Reed-Solomon error correction algorithm. - Better name for the controller structure. - Remove unused caller_is_module() definition. - Make subop helpers return unsigned values. - Expose _notsupp() helpers for raw page accessors. - Add default values for dynamic timings. - Kill the chip->scan_bbt() hook. - Rename nand_default_bbt() into nand_create_bbt(). - Start to clean the nand_chip structure. - Remove stale prototype from rawnand.h. Raw NAND controllers drivers changes: - Qcom: structuring cleanup. - Denali: use core helper to find the best ECC configuration. - Possible build of almost all drivers by adding a dependency on COMPILE_TEST for almost all of them in Kconfig, implies various fixes, Kconfig cleanup, GPIO headers inclusion cleanup, and even changes in sparc64 and ia64 architectures. - Clean the ->probe() functions error path of a lot of drivers. - Migrate all drivers to use nand_scan() instead of nand_scan_ident()/nand_scan_tail() pair. - Use mtd_device_register() where applicable to simplify the code. - Marvell: * Handle on-die ECC. * Better clocks handling. * Remove bogus comment. * Add suspend and resume support. - Tegra: add NAND controller driver. - Atmel: * Add module param to avoid using dma. * Drop Wenyou Yang from MAINTAINERS. - Denali: optimize timings handling. - FSMC: Stop using chip->read_buf(). - FSL: * Switch to SPDX license tag identifiers. * Fix qualifiers in MXC init functions. Raw NAND chip drivers changes: - Micron: * Add fixup for ONFI revision. * Update ecc_stats.corrected. * Make ECC activation stateful. * Avoid enabling/disabling ECC when it can't be disabled. * Get the actual number of bitflips. * Allow forced on-die ECC. * Support 8/512 on-die ECC. * Fix on-die ECC detection logic. - Hynix: * Fix decoding the OOB size on H27UCG8T2BTR. * Use ->exec_op() in hynix_nand_reg_write_op()" * tag 'mtd/for-4.19' of git://git.infradead.org/linux-mtd: (188 commits) mtd: rawnand: atmel: Select GENERIC_ALLOCATOR MAINTAINERS: drop Wenyou Yang from Atmel NAND driver support mtd: rawnand: allocate dynamically ONFI parameters during detection mtd: spi-nor: only apply reset hacks to broken hardware mtd: spi-nor: cadence-quadspi: fix timeout handling mtd: spi-nor: atmel-quadspi: Include gpio/consumer.h instead of gpio.h mtd: spi-nor: intel-spi: use mtd_device_register() mtd: spi-nor: stm32-quadspi: replace "%p" with "%pK" mtd: spi-nor: atmel-quadspi: add suspend/resume hooks mtd: rawnand: allocate model parameter dynamically mtd: rawnand: do not export nand_scan_[ident|tail]() anymore mtd: rawnand: txx9ndfmc: convert driver to nand_scan() mtd: rawnand: txx9ndfmc: clarify ECC parameters assignation mtd: rawnand: tegra: convert driver to nand_scan() mtd: rawnand: jz4740: convert driver to nand_scan() mtd: rawnand: jz4740: group nand_scan_{ident, tail} calls mtd: rawnand: jz4740: fix probe function error path mtd: rawnand: docg4: convert driver to nand_scan() mtd: rawnand: do not execute nand_scan_ident() if maxchips is zero mtd: rawnand: atmel: convert driver to nand_scan() ...
2018-08-14Merge tag 'mips_4.19' of ↵Linus Torvalds45-10938/+1247
git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux Pull MIPS updates from Paul Burton: "Here are the main MIPS changes for 4.19. An overview of the general architecture changes: - Massive DMA ops refactoring from Christoph Hellwig (huzzah for deleting crufty code!). - We introduce NT_MIPS_DSP & NT_MIPS_FP_MODE ELF notes & corresponding regsets to expose DSP ASE & floating point mode state respectively, both for live debugging & core dumps. - We better optimize our code by hard-coding cpu_has_* macros at compile time where their values are known due to the ISA revision that the kernel build is targeting. - The EJTAG exception handler now better handles SMP systems, where it was previously possible for CPUs to clobber a register value saved by another CPU. - Our implementation of memset() gained a couple of fixes for MIPSr6 systems to return correct values in some cases where stores fault. - We now implement ioremap_wc() using the uncached-accelerated cache coherency attribute where supported, which is detected during boot, and fall back to plain uncached access where necessary. The MIPS-specific (and unused in tree) ioremap_uncached_accelerated() & ioremap_cacheable_cow() are removed. - The prctl(PR_SET_FP_MODE, ...) syscall is better supported for SMP systems by reworking the way we ensure remote CPUs that may be running threads within the affected process switch mode. - Systems using the MIPS Coherence Manager will now set the MIPS_IC_SNOOPS_REMOTE flag to avoid some unnecessary cache maintenance overhead when flushing the icache. - A few fixes were made for building with clang/LLVM, which now sucessfully builds kernels for many of our platforms. - Miscellaneous cleanups all over. And some platform-specific changes: - ar7 gained stubs for a few clock API functions to fix build failures for some drivers. - ath79 gained support for a few new SoCs, a few fixes & better gpio-keys support. - Ci20 now exposes its SPI bus using the spi-gpio driver. - The generic platform can now auto-detect a suitable value for PHYS_OFFSET based upon the memory map described by the device tree, allowing us to avoid wasting memory on page book-keeping for systems where RAM starts at a non-zero physical address. - Ingenic systems using the jz4740 platform code now link their vmlinuz higher to allow for kernels of a realistic size. - Loongson32 now builds the kernel targeting MIPSr1 rather than MIPSr2 to avoid CPU errata. - Loongson64 gains a couple of fixes, a workaround for a write buffering issue & support for the Loongson 3A R3.1 CPU. - Malta now uses the piix4-poweroff driver to handle powering down. - Microsemi Ocelot gained support for its SPI bus & NOR flash, its second MDIO bus and can now be supported by a FIT/.itb image. - Octeon saw a bunch of header cleanups which remove a lot of duplicate or unused code" * tag 'mips_4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (123 commits) MIPS: Remove remnants of UASM_ISA MIPS: netlogic: xlr: Remove erroneous check in nlm_fmn_send() MIPS: VDSO: Force link endianness MIPS: Always specify -EB or -EL when using clang MIPS: Use dins to simplify __write_64bit_c0_split() MIPS: Use read-write output operand in __write_64bit_c0_split() MIPS: Avoid using array as parameter to write_c0_kpgd() MIPS: vdso: Allow clang's --target flag in VDSO cflags MIPS: genvdso: Remove GOT checks MIPS: Remove obsolete MIPS checks for DST node "chosen@0" MIPS: generic: Remove input symbols from defconfig MIPS: Delete unused code in linux32.c MIPS: Remove unused sys_32_mmap2 MIPS: Remove nabi_no_regargs mips: dts: mscc: enable spi and NOR flash support on ocelot PCB123 mips: dts: mscc: Add spi on Ocelot MIPS: Loongson: Merge load addresses MIPS: Loongson: Set Loongson32 to MIPS32R1 MIPS: mscc: ocelot: add interrupt controller properties to GPIO controller MIPS: generic: Select MIPS_AUTO_PFN_OFFSET ...
2018-08-13Merge branch 'perf-core-for-linus' of ↵Linus Torvalds1-13/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf update from Thomas Gleixner: "The perf crowd presents: Kernel updates: - Removal of jprobes - Cleanup and consolidatation the handling of kprobes - Cleanup and consolidation of hardware breakpoints - The usual pile of fixes and updates to PMUs and event descriptors Tooling updates: - Updates and improvements all over the place. Nothing outstanding, just the (good) boring incremental grump work" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits) perf trace: Do not require --no-syscalls to suppress strace like output perf bpf: Include uapi/linux/bpf.h from the 'perf trace' script's bpf.h perf tools: Allow overriding MAX_NR_CPUS at compile time perf bpf: Show better message when failing to load an object perf list: Unify metric group description format with PMU event description perf vendor events arm64: Update ThunderX2 implementation defined pmu core events perf cs-etm: Generate branch sample for CS_ETM_TRACE_ON packet perf cs-etm: Generate branch sample when receiving a CS_ETM_TRACE_ON packet perf cs-etm: Support dummy address value for CS_ETM_TRACE_ON packet perf cs-etm: Fix start tracing packet handling perf build: Fix installation directory for eBPF perf c2c report: Fix crash for empty browser perf tests: Fix indexing when invoking subtests perf trace: Beautify the AF_INET & AF_INET6 'socket' syscall 'protocol' args perf trace beauty: Add beautifiers for 'socket''s 'protocol' arg perf trace beauty: Do not print NULL strarray entries perf beauty: Add a generator for IPPROTO_ socket's protocol constants tools include uapi: Grab a copy of linux/in.h perf tests: Fix complex event name parsing perf evlist: Fix error out while applying initial delay and LBR ...
2018-08-13Merge branch 'locking-core-for-linus' of ↵Linus Torvalds1-172/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking/atomics update from Thomas Gleixner: "The locking, atomics and memory model brains delivered: - A larger update to the atomics code which reworks the ordering barriers, consolidates the atomic primitives, provides the new atomic64_fetch_add_unless() primitive and cleans up the include hell. - Simplify cmpxchg() instrumentation and add instrumentation for xchg() and cmpxchg_double(). - Updates to the memory model and documentation" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits) locking/atomics: Rework ordering barriers locking/atomics: Instrument cmpxchg_double*() locking/atomics: Instrument xchg() locking/atomics: Simplify cmpxchg() instrumentation locking/atomics/x86: Reduce arch_cmpxchg64*() instrumentation tools/memory-model: Rename litmus tests to comply to norm7 tools/memory-model/Documentation: Fix typo, smb->smp sched/Documentation: Update wake_up() & co. memory-barrier guarantees locking/spinlock, sched/core: Clarify requirements for smp_mb__after_spinlock() sched/core: Use smp_mb() in wake_woken_function() tools/memory-model: Add informal LKMM documentation to MAINTAINERS locking/atomics/Documentation: Describe atomic_set() as a write operation tools/memory-model: Make scripts executable tools/memory-model: Remove ACCESS_ONCE() from model tools/memory-model: Remove ACCESS_ONCE() from recipes locking/memory-barriers.txt/kokr: Update Korean translation to fix broken DMA vs. MMIO ordering example MAINTAINERS: Add Daniel Lustig as an LKMM reviewer tools/memory-model: Fix ISA2+pooncelock+pooncelock+pombonce name tools/memory-model: Add litmus test for full multicopy atomicity locking/refcount: Always allow checked forms ...
2018-08-11MIPS: Consistently declare TLB functionsPaul Burton2-0/+10
Since at least the beginning of the git era we've declared our TLB exception handling functions inconsistently. They're actually functions, but we declare them as arrays of u32 where each u32 is an encoded instruction. This has always been the case for arch/mips/mm/tlbex.c, and has also been true for arch/mips/kernel/traps.c since commit 86a1708a9d54 ("MIPS: Make tlb exception handler definitions and declarations match.") which aimed for consistency but did so by consistently making the our C code inconsistent with our assembly. This is all usually harmless, but when using GCC 7 or newer to build a kernel targeting microMIPS (ie. CONFIG_CPU_MICROMIPS=y) it becomes problematic. With microMIPS bit 0 of the program counter indicates the ISA mode. When bit 0 is zero instructions are decoded using the standard MIPS32 or MIPS64 ISA. When bit 0 is one instructions are decoded using microMIPS. This means that function pointers become odd - their least significant bit is one for microMIPS code. We work around this in cases where we need to access code using loads & stores with our msk_isa16_mode() macro which simply clears bit 0 of the value it is given: #define msk_isa16_mode(x) ((x) & ~0x1) For example we do this for our TLB load handler in build_r4000_tlb_load_handler(): u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbl); We then write code to p, expecting it to be suitably aligned (our LEAF macro aligns functions on 4 byte boundaries, so (ulong)handle_tlbl will give a value one greater than a multiple of 4 - ie. the start of a function on a 4 byte boundary, with the ISA mode bit 0 set). This worked fine up to GCC 6, but GCC 7 & onwards is smart enough to presume that handle_tlbl which we declared as an array of u32s must be aligned sufficiently that bit 0 of its address will never be set, and as a result optimize out msk_isa16_mode(). This leads to p having an address with bit 0 set, and when we go on to attempt to store code at that address we take an address error exception due to the unaligned memory access. This leads to an exception prior to the kernel having configured its own exception handlers, so we jump to whatever handlers the bootloader configured. In the case of QEMU this results in a silent hang, since it has no useful general exception vector. Fix this by consistently declaring our TLB-related functions as functions. For handle_tlbl(), handle_tlbs() & handle_tlbm() we do this in asm/tlbex.h & we make use of the existing declaration of tlbmiss_handler_setup_pgd() in asm/mmu_context.h. Our TLB handler generation code in arch/mips/mm/tlbex.c is adjusted to deal with these definitions, in most cases simply by casting the function pointers to u32 pointers. This allows us to include asm/mmu_context.h in arch/mips/mm/tlbex.c to get the definitions of tlbmiss_handler_setup_pgd & pgd_current, removing some needless duplication. Consistently using msk_isa16_mode() on function pointers means we no longer need the tlbmiss_handler_setup_pgd_start symbol so that is removed entirely. Now that we're declaring our functions as functions GCC stops optimizing out msk_isa16_mode() & a microMIPS kernel built with either GCC 7.3.0 or 8.1.0 boots successfully. Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-11MIPS: Export tlbmiss_handler_setup_pgd near its definitionPaul Burton1-0/+1
We export tlbmiss_handler_setup_pgd in arch/mips/mm/tlbex.c close to a declaration of it, rather than close to its definition as is standard. We've supported exporting symbols in assembly code since commit 22823ab419d8 ("EXPORT_SYMBOL() for asm"), so move the export to follow the function's (stub) definition. Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-08MIPS: netlogic: xlr: Remove erroneous check in nlm_fmn_send()Paul Burton1-2/+0
In nlm_fmn_send() we have a loop which attempts to send a message multiple times in order to handle the transient failure condition of a lack of available credit. When examining the status register to detect the failure we check for a condition that can never be true, which falls foul of gcc 8's -Wtautological-compare: In file included from arch/mips/netlogic/common/irq.c:65: ./arch/mips/include/asm/netlogic/xlr/fmn.h: In function 'nlm_fmn_send': ./arch/mips/include/asm/netlogic/xlr/fmn.h:304:22: error: bitwise comparison always evaluates to false [-Werror=tautological-compare] if ((status & 0x2) == 1) ^~ If the path taken if this condition were true all we do is print a message to the kernel console. Since failures seem somewhat expected here (making the console message questionable anyway) and the condition has clearly never evaluated true we simply remove it, rather than attempting to fix it to check status correctly. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/20174/ Cc: Ganesan Ramalingam <ganesanr@broadcom.com> Cc: James Hogan <jhogan@kernel.org> Cc: Jayachandran C <jnair@caviumnetworks.com> Cc: John Crispin <john@phrozen.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-08-07MIPS: Use dins to simplify __write_64bit_c0_split()Paul Burton1-1/+10
The code in __write_64bit_c0_split() is used by MIPS32 kernels running on MIPS64 CPUs to write a 64-bit value to a 64-bit coprocessor 0 register using a single 64-bit dmtc0 instruction. It does this by combining the 2x 32-bit registers used to hold the 64-bit value into a single register, which in the existing code involves three steps: 1) Zero extend register A which holds bits 31:0 of our data, since it may have previously held a sign-extended value. 2) Shift register B which holds bits 63:32 of our data in bits 31:0 left by 32 bits, such that the bits forming our data are in the position they'll be in the final 64-bit value & bits 31:0 of the register are zero. 3) Or the two registers together to form the 64-bit value in one 64-bit register. From MIPS r2 onwards we have a dins instruction which can effectively perform all 3 of those steps using a single instruction. Add a path for MIPS r2 & beyond which uses dins to take bits 31:0 from register B & insert them into bits 63:32 of register A, giving us our full 64-bit value in register A with one instruction. Since we know that MIPS r2 & above support the sel field for the dmtc0 instruction, we don't bother special casing sel==0. Omiting the sel field would assemble to exactly the same instruction as when we explicitly specify that it equals zero. Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-07MIPS: Use read-write output operand in __write_64bit_c0_split()Paul Burton1-9/+7
Commit c22c80431055 ("MIPS: Fix input modify in __write_64bit_c0_split()") modified __write_64bit_c0_split() constraints such that we have both an input & an output which we hope to assign to the same registers, and modify the output rather than incorrectly clobbering an input. The way in which we use both an output & an input parameter with the input constrained to share the output registers is a little convoluted & also problematic for clang, which complains if the input & output values have different widths. For example: In file included from kernel/fork.c:98: ./arch/mips/include/asm/mmu_context.h:149:19: error: unsupported inline asm: input with type 'unsigned long' matching output with type 'unsigned long long' write_c0_entryhi(cpu_asid(cpu, next)); ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~ ./arch/mips/include/asm/mmu_context.h:93:2: note: expanded from macro 'cpu_asid' (cpu_context((cpu), (mm)) & cpu_asid_mask(&cpu_data[cpu])) ^ ./arch/mips/include/asm/mipsregs.h:1617:65: note: expanded from macro 'write_c0_entryhi' #define write_c0_entryhi(val) __write_ulong_c0_register($10, 0, val) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~ ./arch/mips/include/asm/mipsregs.h:1430:39: note: expanded from macro '__write_ulong_c0_register' __write_64bit_c0_register(reg, sel, val); \ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~ ./arch/mips/include/asm/mipsregs.h:1400:41: note: expanded from macro '__write_64bit_c0_register' __write_64bit_c0_split(register, sel, value); \ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~ ./arch/mips/include/asm/mipsregs.h:1498:13: note: expanded from macro '__write_64bit_c0_split' : "r,0" (val)); \ ^~~ We can both fix this build failure & simplify the code somewhat by assigning the __tmp variable with the input value in C prior to our inline assembly, and then using a single read-write output operand (ie. a constraint beginning with +) to provide this value to our assembly. Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-02Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-3/+0
The BTF conflicts were simple overlapping changes. The virtio_net conflict was an overlap of a fix of statistics counter, happening alongisde a move over to a bonafide statistics structure rather than counting value on the stack. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-02Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar1-3/+0
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-08-01MIPS: Remove nabi_no_regargsPaul Burton1-12/+0
Our sigreturn functions make use of a macro named nabi_no_regargs to declare 8 dummy arguments to a function, forcing the compiler to expect a pt_regs structure on the stack rather than in argument registers. This is an ugly hack which unnecessarily causes these sigreturn functions to need to care about the calling convention of the ABI the kernel is built for. Although this is abstracted via nabi_no_regargs, it's still ugly & unnecessary. Remove nabi_no_regargs & the struct pt_regs argument from sigreturn functions, and instead use current_pt_regs() to find the struct pt_regs on the stack, which works cleanly regardless of ABI. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/20106/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-07-30MIPS: Allow auto-dection of ARCH_PFN_OFFSET & PHYS_OFFSETPaul Burton2-4/+13
On systems where physical memory begins at a non-zero address, defining PHYS_OFFSET (which influences ARCH_PFN_OFFSET) can save us time & memory by avoiding book-keeping for pages from address zero to the start of memory. Some MIPS platforms already make use of this, but with the definition of PHYS_OFFSET being compile-time constant it hasn't been possible to enable this optimization for a kernel which may run on systems with varying physical memory base addresses. Introduce a new Kconfig option CONFIG_MIPS_AUTO_PFN_OFFSET which, when enabled, makes ARCH_PFN_OFFSET a variable & detects it from the boot memory map (which for example may have been populated from DT). The relationship with PHYS_OFFSET is reversed, with PHYS_OFFSET now being based on ARCH_PFN_OFFSET. This is because ARCH_PFN_OFFSET is used far more often, so avoiding the need for runtime calculation gives us a smaller impact on kernel text size (0.1% rather than 0.15% for 64r6el_defconfig). Signed-off-by: Paul Burton <paul.burton@mips.com> Suggested-by: Vladimir Kondratiev <vladimir.kondratiev@intel.com> Patchwork: https://patchwork.linux-mips.org/patch/20048/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-07-30MIPS: Fix ISA virt/bus conversion for non-zero PHYS_OFFSETPaul Burton1-4/+4
isa_virt_to_bus() & isa_bus_to_virt() claim to treat ISA bus addresses as being identical to physical addresses, but they fail to do so in the presence of a non-zero PHYS_OFFSET. Correct this by having them use virt_to_phys() & phys_to_virt(), which consolidates the calculations to one place & ensures that ISA bus addresses do indeed match physical addresses. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/20047/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
2018-07-30MIPS: Make (UN)CAC_ADDR() PHYS_OFFSET-agnosticPaul Burton3-6/+2
Converting an address between cached & uncached (typically addresses in (c)kseg0 & (c)kseg1 or 2 xkphys regions) should not depend upon PHYS_OFFSET in any way - we're converting from a virtual address in one unmapped region to a virtual address in another unmapped region. For some reason our CAC_ADDR() & UNCAC_ADDR() macros make use of PAGE_OFFSET, which typically includes PHYS_OFFSET. This means that platforms with a non-zero PHYS_OFFSET typically have to workaround miscalculation by these 2 macros by also defining UNCAC_BASE to a value that isn't really correct. It appears that an attempt has previously been made to address this with commit 3f4579252aa1 ("MIPS: make CAC_ADDR and UNCAC_ADDR account for PHYS_OFFSET") which was later undone by commit ed3ce16c3d2b ("Revert "MIPS: make CAC_ADDR and UNCAC_ADDR account for PHYS_OFFSET"") which also introduced the ar7 workaround. That attempt at a fix was roughly equivalent, but essentially caused the CAC_ADDR() & UNCAC_ADDR() macros to cancel out PHYS_OFFSET by adding & then subtracting it again. In his revert Leonid is correct that using PHYS_OFFSET makes no sense in the context of these macros, but appears to have missed its inclusion via PAGE_OFFSET which means PHYS_OFFSET actually had an effect after the revert rather than before it. Here we fix this by modifying CAC_ADDR() & UNCAC_ADDR() to stop using PAGE_OFFSET (& thus PHYS_OFFSET), instead using __pa() & __va() along with UNCAC_BASE. For UNCAC_ADDR(), __pa() will convert a cached address to a physical address which we can simply use as an offset from UNCAC_BASE to obtain an address in the uncached region. For CAC_ADDR() we can undo the effect of UNCAC_ADDR() by subtracting UNCAC_BASE and using __va() on the result. With this change made, remove definitions of UNCAC_BASE from the ar7 & pic32 platforms which appear to have defined them only to workaround this problem. Signed-off-by: Paul Burton <paul.burton@mips.com> References: 3f4579252aa1 ("MIPS: make CAC_ADDR and UNCAC_ADDR account for PHYS_OFFSET") References: ed3ce16c3d2b ("Revert "MIPS: make CAC_ADDR and UNCAC_ADDR account for PHYS_OFFSET"") Patchwork: https://patchwork.linux-mips.org/patch/20046/ Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
2018-07-28MIPS: VDSO: Prevent use of smp_processor_id()Paul Burton1-1/+11
VDSO code should not be using smp_processor_id(), since it is executed in user mode. Introduce a VDSO-specific path which will cause a compile-time or link-time error (depending upon support for __compiletime_error) if the VDSO ever incorrectly attempts to use smp_processor_id(). [Matt Redfearn <matt.redfearn@imgtec.com>: Move before change to smp_processor_id in series] Signed-off-by: Paul Burton <paul.burton@mips.com> Signed-off-by: Matt Redfearn <matt.redfearn@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/17932/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: linux-mips@linux-mips.org
2018-07-28MIPS: remove mips_swiotlb_opsChristoph Hellwig1-2/+3
mips_swiotlb_ops differs from the generic swiotlb_dma_ops only in that it contains a mb() barrier after each operations that maps or syncs dma memory to the device. The dma operations are defined to not be memory barriers, but instead the write* operations to kick the DMA off are supposed to contain them. For mips this handled by war_io_reorder_wmb(), which evaluates to the stronger wmb() instead of the pure compiler barrier barrier() for just those platforms that use swiotlb, so I think we are covered properly. [paul.burton@mips.com: - Include linux/swiotlb.h to fix build failures for configs with CONFIG_SWIOTLB=y.] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/20038/ Cc: David Daney <ddaney@caviumnetworks.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: linux-mips@linux-mips.org Cc: iommu@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org
2018-07-27Revert "MIPS: BCM47XX: Enable 74K Core ExternalSync for PCIe erratum"Rafał Miłecki1-3/+0
This reverts commit 2a027b47dba6 ("MIPS: BCM47XX: Enable 74K Core ExternalSync for PCIe erratum"). Enabling ExternalSync caused a regression for BCM4718A1 (used e.g. in Netgear E3000 and ASUS RT-N16): it simply hangs during PCIe initialization. It's likely that BCM4717A1 is also affected. I didn't notice that earlier as the only BCM47XX devices with PCIe I own are: 1) BCM4706 with 2 x 14e4:4331 2) BCM4706 with 14e4:4360 and 14e4:4331 it appears that BCM4706 is unaffected. While BCM5300X-ES300-RDS.pdf seems to document that erratum and its workarounds (according to quotes provided by Tokunori) it seems not even Broadcom follows them. According to the provided info Broadcom should define CONF7_ES in their SDK's mipsinc.h and implement workaround in the si_mips_init(). Checking both didn't reveal such code. It *could* mean Broadcom also had some problems with the given workaround. Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Signed-off-by: Paul Burton <paul.burton@mips.com> Reported-by: Michael Marley <michael@michaelmarley.com> Patchwork: https://patchwork.linux-mips.org/patch/20032/ URL: https://bugs.openwrt.org/index.php?do=details&task_id=1688 Cc: Tokunori Ikegami <ikegami@allied-telesis.co.jp> Cc: Hauke Mehrtens <hauke@hauke-m.de> Cc: Chris Packham <chris.packham@alliedtelesis.co.nz> Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-07-26MIPS: TXx9: remove useless RTC definitionsAlexandre Belloni1-29/+0
The RTC definitions were moved to the driver, remove them from the platform header. [paul.burton@mips.com: - Also remove the unused tx4939_rtcptr which would use struct tx4939_rtc_reg if it were ever expanded.] Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/20024/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org
2018-07-25MIPS: ath79: finetune cpu-overridesFelix Fietkau1-0/+6
This patch adds a few additional cpu feature overrides so that they do not need to be probed at runtime. Signed-off-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: John Crispin <john@phrozen.org> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19914/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-07-25MIPS: ath79: fix system restartFelix Fietkau1-0/+1
This patch disables irq on reboot to fix hang issues that were observed due to pending interrupts. Signed-off-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: John Crispin <john@phrozen.org> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19913/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-07-25MIPS: ath79: add support for QCA953x QCA956x TP9343Matthias Schiffer1-0/+33
This patch adds support for 2 new types of QCA silicon. TP9343 is essentially the same as the QCA956X but is licensed by TPLink. Signed-off-by: Weijie Gao <hackpascal@gmail.com> Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: John Crispin <john@phrozen.org> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19911/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-07-25MIPS: ath79: add lots of missing registersGabor Juhos1-1/+770
This patch adds many new registers for various QCA MIPS SoCs. The patch is an aggragate of many contributions made to OpenWrt. Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Henryk Heisig <hyniu@o2.pl> Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: Weijie Gao <hackpascal@gmail.com> Signed-off-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: Julien Dusser <julien.dusser@free.fr> Signed-off-by: John Crispin <john@phrozen.org> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19910/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-07-25MIPS: Octeon: Remove extern declarations.Steven J. Hill7-11/+22
Get rid of extern declarations in .c functions and included the necessary header file. Also remove unused UART declares. Signed-off-by: Steven J. Hill <steven.hill@cavium.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19477/ Cc: linux-mips@linux-mips.org
2018-07-25MIPS: Hardcode cpu_has_* where known at compile time due to ISAPaul Burton1-69/+107
Many architectural features have over time moved from being optional to either be required or removed by newer architecture releases. This means that in many cases we can know at compile time whether a feature will be supported or not purely due to the knowledge we have about the ISA the kernel build is targeting. This patch introduces a bunch of utility macros for checking for supported options, ASEs & combinations of those with ISA revisions. It then makes use of these in the default definitions of cpu_has_* macros. The result is that many of the macros become compile-time constant, allowing more optimisation opportunities for the compiler - particularly with kernels built for later ISA revisions. To demonstrate the effect of this patch, the following table shows the size in bytes of the kernel binary as reported by scripts/bloat-o-meter for v4.12-rc4 maltasmvp_defconfig kernels with & without this patch. A variant of maltasmvp_defconfig with CONFIG_CPU_MIPS32_R6 selected is also shown, to demonstrate that MIPSr6 systems benefit more due to extra features becoming required by that architecture revision. Builds of pistachio_defconfig are also shown, as although this is a MIPSr2 platform it doesn't hardcode any features in a machine-specific cpu-feature-overrides.h, which allows it to gain more from this patch than the equivalent Malta r2 build. Config | Before | After | Change ----------------|---------|---------|--------- maltasmvp | 7248316 | 7247714 | -602 maltasmvp + r6 | 6955595 | 6950777 | -4818 pistachio | 8650977 | 8363898 | -287079 Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/16360/ Cc: Joshua Kinard <kumba@gentoo.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-07-24mips: use asm-generic version of msi.hThomas Petazzoni1-0/+1
This is necessary to be able to include <linux/msi.h> when CONFIG_GENERIC_MSI_IRQ_DOMAIN is enabled. Without this, a build with CONFIG_GENERIC_MSI_IRQ_DOMAIN fails with: In file included from include/linux/kvm_host.h:20:0, from arch/mips/kernel/asm-offsets.c:24: >> include/linux/msi.h:197:10: fatal error: asm/msi.h: No such file or directory #include <asm/msi.h> ^~~~~~~~~~~ compilation terminated. make[2]: *** [arch/mips/kernel/asm-offsets.s] Error 1 make[2]: Target '__build' not remade because of errors. make[1]: *** [prepare0] Error 2 make[1]: Target 'prepare' not remade because of errors. make: *** [sub-make] Error 2 Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19986/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Hanna Hawa <hannah@marvell.com>
2018-07-24MIPS: Loongson64: Define and use some CP0 registersHuacai Chen2-12/+14
Defines CP0_CONFIG3, CP0_CONFIG6, CP0_PAGEGRAIN and use them in kernel-entry-init.h for Loongson64. Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19264/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <james.hogan@mips.com> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: Huacai Chen <chenhuacai@gmail.com>
2018-07-24MIPS: Loongson: Add Loongson-3A R3.1 basic supportHuacai Chen1-25/+26
Loongson-3A R3.1 is the bugfix revision of Loongson-3A R3. All Loongson-3 CPU family: Code-name Brand-name PRId Loongson-3A R1 Loongson-3A1000 0x6305 Loongson-3A R2 Loongson-3A2000 0x6308 Loongson-3A R3 Loongson-3A3000 0x6309 Loongson-3A R3.1 Loongson-3A3000 0x630d Loongson-3B R1 Loongson-3B1000 0x6306 Loongson-3B R2 Loongson-3B1500 0x6307 Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19263/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <james.hogan@mips.com> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: Huacai Chen <chenhuacai@gmail.com>
2018-07-23MIPS: Change definition of cpu_relax() for Loongson-3Huacai Chen1-0/+13
Linux expects that if a CPU modifies a memory location, then that modification will eventually become visible to other CPUs in the system. Loongson 3 CPUs include a Store Fill Buffer (SFB) which sits between a core & its L1 data cache, queueing memory accesses & allowing for faster forwarding of data from pending stores to younger loads from the core. Unfortunately the SFB prioritizes loads such that a continuous stream of loads may cause a pending write to be buffered indefinitely. This is problematic if we end up with 2 CPUs which each perform a store that the other polls for - one or both CPUs may end up with their stores buffered in the SFB, never reaching cache due to the continuous reads from the poll loop. Such a deadlock condition has been observed whilst running qspinlock code. This patch changes the definition of cpu_relax() to smp_mb() for Loongson-3, forcing a flush of the SFB on SMP systems which will cause any pending writes to make it as far as the L1 caches where they will become visible to other CPUs. If the kernel is not compiled for SMP support, this will expand to a barrier() as before. This workaround matches that currently implemented for ARM when CONFIG_ARM_ERRATA_754327=y, which was introduced by commit 534be1d5a2da ("ARM: 6194/1: change definition of cpu_relax() for ARM11MPCore"). Although the workaround is only required when the Loongson 3 SFB functionality is enabled, and we only began explicitly enabling that functionality in v4.7 with commit 1e820da3c9af ("MIPS: Loongson-3: Introduce CONFIG_LOONGSON3_ENHANCEMENT"), existing or future firmware may enable the SFB which means we may need the workaround backported to earlier kernels too. [paul.burton@mips.com: - Reword commit message & comment. - Limit stable backport to v3.15+ where we support Loongson 3 CPUs.] Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Paul Burton <paul.burton@mips.com> References: 534be1d5a2da ("ARM: 6194/1: change definition of cpu_relax() for ARM11MPCore") References: 1e820da3c9af ("MIPS: Loongson-3: Introduce CONFIG_LOONGSON3_ENHANCEMENT") Patchwork: https://patchwork.linux-mips.org/patch/19830/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: Huacai Chen <chenhuacai@gmail.com> Cc: stable@vger.kernel.org # v3.15+
2018-07-21mips: mm: Discard ioremap_cacheable_cow() methodSerge Semin1-7/+0
This macro substitution is the shortcut to map cacheable IO memory with coherent and write-back attributes. Since it is entirely unused by kernel, lets just remove it. Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Suggested-by: Christoph Hellwig <hch@infradead.org> Patchwork: https://patchwork.linux-mips.org/patch/19937/ CC: Paul Burton <paul.burton@mips.com> Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Sinan Kaya <okaya@codeaurora.org> Cc: Huacai Chen <chenhc@lemote.com> Cc: Sergey.Semin@t-platforms.ru Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org