linux/arch/mips/lib, branch v5.6

MIPS: Make DIEI support as a config option

2020-01-23T18:26:16Z

DI(Disable Interrupt) and EI(Enable Interrupt) instructions is required by MIPSR2/MIPSR6, however, it appears to be buggy on some processors such as Loongson-3A1000. Thus we make it as a config option to allow disable it at compile time with CPU_MIPSR2 selected. Signed-off-by: Jiaxun Yang Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: chenhc@lemote.com Cc: paul.burton@mips.com Cc: linux-kernel@vger.kernel.org

MIPS: make CPU_HAS_LOAD_STORE_LR opt-out

2020-01-22T18:16:47Z

CPU_HAS_LOAD_STORE_LR was introduced in 932afdeec18b ("MIPS: Add Kconfig variable for CPUs with unaligned load/store instructions") to make code in kernel/unaligned.c and lib/mem{cpy,set}.S more intuitive and give a possibility to easily add new CPUs without these instruction sets in future. Hovewer, this variant is not optimal for mainly two reasons: * For now, we have 20+ CPUs with such instructions and only two (MIPS R6) without. It will obviously be more effective and straightforward to have an option for these two rather than for the rest. * You can easily miss the fact that you need to select this option when adding a new CPU, while all processors lacking these sets are well-known, so the probability of missing something is way much lower. We can address both points by turning CPU_HAS_LOAD_STORE_LR into opt-out CPU_NO_LOAD_STORE_LR. This also makes MIPS root Kconfig more clear and understandable. Signed-off-by: Alexander Lobakin Signed-off-by: Paul Burton Cc: Ralf Baechle Cc: Alexandre Belloni Cc: Microchip Linux Driver Support Cc: Will Deacon Cc: Greg Kroah-Hartman Cc: Masahiro Yamada Cc: Paul Walmsley Cc: Michal Simek Cc: Allison Randal Cc: Thomas Gleixner Cc: Eric W. Biederman Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org

MIPS: Loongson64: Rename CPU TYPES

2019-10-31T22:03:10Z

CPU_LOONGSON2 -> CPU_LOONGSON2EF CPU_LOONGSON3 -> CPU_LOONGSON64 As newer loongson-2 products (2G/2H/2K1000) can share kernel implementation with loongson-3 while 2E/2F are less similar with other LOONGSON64 products. Signed-off-by: Jiaxun Yang Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: chenhc@lemote.com Cc: paul.burton@mips.com

MIPS: bitops: Use BIT_WORD() & BITS_PER_LONG

2019-10-07T16:42:55Z

Rather than using custom SZLONG_LOG & SZLONG_MASK macros to shift & mask a bit index to form word & bit offsets respectively, make use of the standard BIT_WORD() & BITS_PER_LONG macros for the same purpose. volatile is added to the definition of pointers to the long-sized word we'll operate on, in order to prevent the compiler complaining that we cast away the volatile qualifier of the addr argument. This should have no effect on generated code, which in the LL/SC case is inline asm anyway & in the non-LLSC case access is constrained by compiler barriers provided by raw_local_irq_{save,restore}(). Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: Huacai Chen Cc: Jiaxun Yang Cc: linux-kernel@vger.kernel.org

MIPS: bitops: Implement test_and_set_bit() in terms of _lock variant

2019-10-07T16:42:47Z

The only difference between test_and_set_bit() & test_and_set_bit_lock() is memory ordering barrier semantics - the former provides a full barrier whilst the latter only provides acquire semantics. We can therefore implement test_and_set_bit() in terms of test_and_set_bit_lock() with the addition of the extra memory barrier. Do this in order to avoid duplicating logic. Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: Huacai Chen Cc: Jiaxun Yang Cc: linux-kernel@vger.kernel.org

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504

2019-06-19T15:09:56Z

Based on 1 normalized pattern(s): this file is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 8 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081207.443595178@linutronix.de Signed-off-by: Greg Kroah-Hartman

MIPS: MemoryMapID (MMID) Support

2019-02-04T18:56:41Z

Introduce support for using MemoryMapIDs (MMIDs) as an alternative to Address Space IDs (ASIDs). The major difference between the two is that MMIDs are global - ie. an MMID uniquely identifies an address space across all coherent CPUs. In contrast ASIDs are non-global per-CPU IDs, wherein each address space is allocated a separate ASID for each CPU upon which it is used. This global namespace allows a new GINVT instruction be used to globally invalidate TLB entries associated with a particular MMID across all coherent CPUs in the system, removing the need for IPIs to invalidate entries with separate ASIDs on each CPU. The allocation scheme used here is largely borrowed from arm64 (see arch/arm64/mm/context.c). In essence we maintain a bitmap to track available MMIDs, and MMIDs in active use at the time of a rollover to a new MMID version are preserved in the new version. The allocation scheme requires efficient 64 bit atomics in order to perform reasonably, so this support depends upon CONFIG_GENERIC_ATOMIC64=n (ie. currently it will only be included in MIPS64 kernels). The first, and currently only, available CPU with support for MMIDs is the MIPS I6500. This CPU supports 16 bit MMIDs, and so for now we cap our MMIDs to 16 bits wide in order to prevent the bitmap growing to absurd sizes if any future CPU does implement 32 bit MMIDs as the architecture manuals suggest is recommended. When MMIDs are in use we also make use of GINVT instruction which is available due to the global nature of MMIDs. By executing a sequence of GINVT & SYNC 0x14 instructions we can avoid the overhead of an IPI to each remote CPU in many cases. One complication is that GINVT will invalidate wired entries (in all cases apart from type 0, which targets the entire TLB). In order to avoid GINVT invalidating any wired TLB entries we set up, we make sure to create those entries using a reserved MMID (0) that we never associate with any address space. Also of note is that KVM will require further work in order to support MMIDs & GINVT, since KVM is involved in allocating IDs for guests & in configuring the MMU. That work is not part of this patch, so for now when MMIDs are in use KVM is disabled. Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org

MIPS: lib: Use kernel_pref & user_pref in memcpy()

2018-10-16T06:11:14Z

memcpy() is the only user of the PREF() & PREFE() macros from asm/asm.h. Switch to using the kernel_pref() & user_pref() macros from asm/asm-eva.h which fit more consistently with other abstractions of EVA vs non-EVA instructions. Signed-off-by: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/20907/ Cc: linux-mips@linux-mips.org

MIPS: memset: Limit excessive `noreorder' assembly mode use

2018-10-09T17:31:03Z

Rewrite to use the `reorder' assembly mode and remove manually scheduled delay slots except where GAS cannot schedule a delay-slot instruction due to a data dependency or a section switch (as is the case with the EX macro). No change in machine code produced. Signed-off-by: Maciej W. Rozycki [paul.burton@mips.com: Fix conflict with commit 932afdeec18b ("MIPS: Add Kconfig variable for CPUs with unaligned load/store instructions")] Signed-off-by: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/20834/ Cc: Ralf Baechle

MIPS: memset: Fix CPU_DADDI_WORKAROUNDS `small_fixup' regression

2018-10-09T17:24:04Z

Fix a commit 8a8158c85e1e ("MIPS: memset.S: EVA & fault support for small_memset") regression and remove assembly warnings: arch/mips/lib/memset.S: Assembler messages: arch/mips/lib/memset.S:243: Warning: Macro instruction expanded into multiple instructions in a branch delay slot triggering with the CPU_DADDI_WORKAROUNDS option set and this code: PTR_SUBU a2, t1, a0 jr ra PTR_ADDIU a2, 1 This is because with that option in place the DADDIU instruction, which the PTR_ADDIU CPP macro expands to, becomes a GAS macro, which in turn expands to an LI/DADDU (or actually ADDIU/DADDU) sequence: 13c: 01a4302f dsubu a2,t1,a0 140: 03e00008 jr ra 144: 24010001 li at,1 148: 00c1302d daddu a2,a2,at ... Correct this by switching off the `noreorder' assembly mode and letting GAS schedule this jump's delay slot, as there is nothing special about it that would require manual scheduling. With this change in place correct code is produced: 13c: 01a4302f dsubu a2,t1,a0 140: 24010001 li at,1 144: 03e00008 jr ra 148: 00c1302d daddu a2,a2,at ... Signed-off-by: Maciej W. Rozycki Signed-off-by: Paul Burton Fixes: 8a8158c85e1e ("MIPS: memset.S: EVA & fault support for small_memset") Patchwork: https://patchwork.linux-mips.org/patch/20833/ Cc: Ralf Baechle Cc: stable@vger.kernel.org # 4.17+