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2018-07-24MIPS: ath79: add lots of missing registersGabor Juhos
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
2018-07-24MIPS: Octeon: Remove extern declarations.Steven J. Hill
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
2018-07-24MIPS: Hardcode cpu_has_* where known at compile time due to ISAPaul Burton
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 Petazzoni
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>
2018-07-23MIPS: Loongson64: Define and use some CP0 registersHuacai Chen
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>
2018-07-23MIPS: Loongson: Add Loongson-3A R3.1 basic supportHuacai Chen
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 Chen
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+
2018-07-20mips: mm: Discard ioremap_cacheable_cow() methodSerge Semin
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
2018-07-19MIPS: Correct the 64-bit DSP accumulator register sizeMaciej W. Rozycki
Use the `unsigned long' rather than `__u32' type for DSP accumulator registers, like with the regular MIPS multiply/divide accumulator and general-purpose registers, as all are 64-bit in 64-bit implementations and using a 32-bit data type leads to contents truncation on context saving. Update `arch_ptrace' and `compat_arch_ptrace' accordingly, removing casts that are similarly not used with multiply/divide accumulator or general-purpose register accesses. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.") Patchwork: https://patchwork.linux-mips.org/patch/19329/ Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # 2.6.15+
2018-07-18MIPS: jz4740: Move jz4740_nand.h header to include/linux/platform_data/jz4740Boris Brezillon
This way we will be able to compile the jz4740_nand driver when COMPILE_TEST=y. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Acked-by: Paul Burton <paul.burton@mips.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
2018-07-18MIPS: txx9: Move the ndfc.h header to include/linux/platform_data/txx9Boris Brezillon
This way we will be able to compile the ndfmc driver when COMPILE_TEST=y. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Acked-by: Paul Burton <paul.burton@mips.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
2018-07-17mips: unify prom_putchar() declarationsAlexander Sverdlin
prom_putchar() is used centrally in early printk infrastructure therefore at least MIPS should agree on the function return type. [paul.burton@mips.com: - Include linux/types.h in asm/setup.h to gain the bool typedef before we start include asm/setup.h elsewhere. - Include asm/setup.h in all files that use or define prom_putchar(). - Also standardise on signed rather than unsigned char argument.] Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19842/ Cc: linux-mips@linux-mips.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Jonas Gorski <jonas.gorski@gmail.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com>
2018-07-17Merge tag 'v4.18-rc5' into locking/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-12MIPS: Cleanup R10000_LLSC_WAR logic in atomic.hJoshua Kinard
This patch reduces down the conditionals in MIPS atomic code that deal with a silicon bug in early R10000 cpus that required a workaround of a branch-likely instruction following a store-conditional in order to to guarantee the whole ll/sc sequence is atomic. As the only real difference is a branch-likely instruction (beqzl) over a standard branch (beqz), the conditional is reduced down to a single preprocessor check at the top to pick the required instruction. This requires writing the uses in assembler, thus we discard the non-R10000 case that uses a mixture of a C do...while loop with embedded assembler that was added back in commit 7837314d141c ("MIPS: Get rid of branches to .subsections."). A note found in the git log for commit 5999eca25c1f ("[MIPS] Improve branch prediction in ll/sc atomic operations.") is also addressed. The macro definition for the branch instruction and the code comment derives from a patch sent in earlier by Paul Burton for various cmpxchg cleanups. [paul.burton@mips.com: - Minor whitespace fix for checkpatch.] Signed-off-by: Joshua Kinard <kumba@gentoo.org> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/17736/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <james.hogan@mips.com> Cc: "Maciej W. Rozycki" <macro@mips.com> Cc: linux-mips@linux-mips.org
2018-07-12MIPS: Fix delay slot bug in `atomic*_sub_if_positive' for R10000_LLSC_WARJoshua Kinard
This patch fixes an old bug in MIPS ll/sc atomics, in the `atomic_sub_if_positive' and `atomic64_sub_if_positive' functions, for the R10000_LLSC_WAR case where the result of the subu/dsubu instruction would potentially not be made available to the sc/scd instruction due to being in the delay-slot of the branch-likely (beqzl) instruction. This also removes the need for the `noreorder' directive, allowing GAS to use delay slot scheduling as needed. The same fix is also applied to the standard branch (beqz) case in preparation for a follow-up patch that will cleanup/merge the R10000_LLSC_WAR and non-R10K sections together. Signed-off-by: Joshua Kinard <kumba@gentoo.org> Signed-off-by: Paul Burton <paul.burton@mips.com> Tested-by: Joshua Kinard <kumba@gentoo.org> Patchwork: https://patchwork.linux-mips.org/patch/17735/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <james.hogan@mips.com> Cc: "Maciej W. Rozycki" <macro@mips.com> Cc: linux-mips@linux-mips.org
2018-07-10mips: mm: Discard ioremap_uncached_accelerated() methodSerge Semin
Adaptive ioremap_wc() method is now available as of commit 9748e33e26c6 ("mips: mm: Create UCA-based ioremap_wc() method"). We can use it to obtain UnCached Accelerated (UCA) mappings safely on all MIPS systems, and so we don't need the MIPS-specific ioremap_uncached_accelerated() any longer. This macro hard-coded the UCA Cache Coherency Attribute (CCA) in a manner that isn't safe for kernels that may run on different CPUs, and it is also entirely unused so we can trivially remove it. [paul.burton@mips.com: - Reword the commit message a little. - Remove CC stable.] Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19790/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: okaya@codeaurora.org Cc: chenhc@lemote.com Cc: Sergey.Semin@t-platforms.ru Cc: linux-kernel@vger.kernel.org
2018-07-10mips: mm: Create UCA-based ioremap_wc() methodSerge Semin
Modern MIPS cores (like P5600/6600, M5150/6520, end so on) which got L2-cache on chip also can enable a special type Cache-Coherency attribute (CCA) named UnCached Accelerated attribute (UCA). In this way uncached accelerated accesses are treated the same way as non-accelerated uncached accesses, but uncached stores are gathered together for more efficient bus utilization. So to speak this CCA enables uncached transactions to better utilize bus bandwidth via burst transactions. This is exactly why ioremap_wc() method has been introduced in Linux. Alas MIPS-platform code hasn't implemented it so far, instead default one has been used which was an alias to ioremap_nocache. In order to fix this we added MIPS-specific ioremap_wc() macro substituted by generic __ioremap_mode() method call with writecombine CPU-info field passed. It shall create real ioremap_wc() method if CPU-cache supports UCA feature and fall-back to _CACHE_UNCACHED attribute if one doesn't. Additionally platform-specific io.h shall declare ARCH_HAS_IOREMAP_WC macro as indication of architectural definition of ioremap_wc() (similar to x86/powerpc). [paul.burton@mips.com: - Remove CC stable, this is new functionality.] Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19789/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: okaya@codeaurora.org Cc: chenhc@lemote.com Cc: Sergey.Semin@t-platforms.ru Cc: linux-kernel@vger.kernel.org
2018-07-04net: Add a new socket option for a future transmit time.Richard Cochran
This patch introduces SO_TXTIME. User space enables this option in order to pass a desired future transmit time in a CMSG when calling sendmsg(2). The argument to this socket option is a 8-bytes long struct provided by the uapi header net_tstamp.h defined as: struct sock_txtime { clockid_t clockid; u32 flags; }; Note that new fields were added to struct sock by filling a 2-bytes hole found in the struct. For that reason, neither the struct size or number of cachelines were altered. Signed-off-by: Richard Cochran <rcochran@linutronix.de> Signed-off-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-03MIPS: Octeon: Simplify CIU register functions.Steven J. Hill
Collapse and simplify switch statements in functions. 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/19713/ Cc: linux-mips@linux-mips.org Cc: Chandrakala Chavva <cchavva@caviumnetworks.com>
2018-07-03MIPS: Octeon: Create simple macro for CIU registers.Steven J. Hill
Create new CVMX_CIU_ADDR macro to improve readability. 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/19712/ Cc: linux-mips@linux-mips.org Cc: Chandrakala Chavva <cchavva@caviumnetworks.com>
2018-07-03MIPS: Octeon: Remove all unused CIU macros.Steven J. Hill
Get rid of all unused CIU macros and sort them. Verified with 'make allyesconfig' build test. [paul.burton@mips.com: - Also checked via convoluted grep invocation for use of all removed macros within arch/mips/ & drivers/.] 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/19710/ Cc: linux-mips@linux-mips.org Cc: Chandrakala Chavva <cchavva@caviumnetworks.com>
2018-07-03MIPS: Octeon: Convert CIU types to use bitfields.Steven J. Hill
Convert remaining structures to use __BITFIELD_FIELD macro. Also straighten up the description text and whitespace. 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/19709/ Cc: linux-mips@linux-mips.org Cc: Chandrakala Chavva <cchavva@caviumnetworks.com>
2018-07-03MIPS: Octeon: Unify QLM data types in CIU header.Steven J. Hill
Data types 'cvmx_ciu_qlm0' and 'cvmx_ciu_qlm1' are identical in their usage and structure. Combine them and update the PCIe code. 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/19708/ Cc: linux-mips@linux-mips.org Cc: Chandrakala Chavva <cchavva@caviumnetworks.com>
2018-07-03MIPS: Octeon: Remove unused CIU types.Steven J. Hill
Remove all unused data types. Verified with a 'make allyesconfig' and Cavium platform. [paul.burton@mips.com: - Also checked via convoluted grep invocation for use of all removed structs & unions within arch/mips/ & drivers/.] 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/19711/ Cc: linux-mips@linux-mips.org Cc: Chandrakala Chavva <cchavva@caviumnetworks.com>
2018-06-26Merge branch 'linus' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-24MIPS: Schedule on CPUs we need to lose FPU for a mode switchPaul Burton
Commit 6b8322576e9d ("MIPS: Force CPUs to lose FP context during mode switches") ensures that we react to PR_SET_FP_MODE prctl syscalls quickly by broadcasting an IPI in order to cause CPUs to lose FPU access when necessary. Whilst it achieves that, unfortunately it causes all sorts of strange race conditions because: 1) The IPI may arrive at a point where the FPU is in the process of being enabled, but that process is not yet complete leading to a state we aren't prepared to handle. For example: [ 370.215903] do_cpu invoked from kernel context![#1]: [ 370.221064] CPU: 0 PID: 963 Comm: fp-prctl Not tainted 4.9.0-rc5-00323-g210db32-dirty #226 [ 370.229420] task: a8000000fd672e00 task.stack: a8000000fd630000 [ 370.235399] $ 0 : 0000000000000000 0000000000000001 0000000000000001 a8000000fd630000 [ 370.243882] $ 4 : a8000000fd672e00 0000000000000000 0000000000000453 0000000000000000 [ 370.252317] $ 8 : 0000000000000000 a8000000fd637c28 1000000000000000 0000000000000010 [ 370.260753] $12 : 00000000140084e0 ffffffff80109c00 0000000000000000 0000000000000002 [ 370.269179] $16 : ffffffff8092f080 a8000000fd672e00 ffffffff80107fe8 a8000000fd485000 [ 370.277612] $20 : ffffffff8084d328 ffffffff80940000 0000000000000009 ffffffff80930000 [ 370.286038] $24 : 0000000000000000 900000001612048c [ 370.294476] $28 : a8000000fd630000 a8000000fd637ac0 ffffffff80937300 ffffffff8010807c [ 370.302909] Hi : 0000000000000000 [ 370.306595] Lo : 0000000000000200 [ 370.310376] epc : ffffffff80115d38 _save_fp+0x10/0xa0 [ 370.315784] ra : ffffffff8010807c prepare_for_fp_mode_switch+0x94/0x1b0 [ 370.322707] Status: 140084e2 KX SX UX KERNEL EXL [ 370.327980] Cause : 1080002c (ExcCode 0b) [ 370.332091] PrId : 0001a428 (MIPS P6600) [ 370.336179] Modules linked in: [ 370.339486] Process fp-prctl (pid: 963, threadinfo=a8000000fd630000, task=a8000000fd672e00, tls=00000000756e67d0) [ 370.349724] Stack : 0000000000000000 a8000000fd557dc0 0000000000000000 ffffffff801ca8e0 [ 370.358161] 0000000000000000 a8000000fd637b9c 0000000000000009 ffffffff80923780 [ 370.366575] ffffffff80850000 ffffffff8011610c 00000000000000b8 ffffffff801a5084 [ 370.374989] ffffffff8084a370 ffffffff8084a388 ffffffff80923780 ffffffff80923828 [ 370.383395] 0000000000010000 ffffffff809237a8 0000000000020000 ffffffff80a40000 [ 370.391817] 000000000000007c 00000000004a0000 00000000756dedd0 ffffffff801a5188 [ 370.400230] a800000002014900 0000000000000001 ffffffff80923780 0000000080923828 [ 370.408644] ffffffff80923780 ffffffff80923780 ffffffff80923828 ffffffff801a521c [ 370.417066] ffffffff80923780 ffffffff80923828 0000000000010000 ffffffff801a8f84 [ 370.425472] ffffffff80a40000 a8000000fd637c20 ffffffff80a39240 0000000000000001 [ 370.433885] ... [ 370.436562] Call Trace: [ 370.439222] [<ffffffff80115d38>] _save_fp+0x10/0xa0 [ 370.444305] [<ffffffff8010807c>] prepare_for_fp_mode_switch+0x94/0x1b0 [ 370.451035] [<ffffffff801ca8e0>] flush_smp_call_function_queue+0xf8/0x230 [ 370.457991] [<ffffffff8011610c>] ipi_call_interrupt+0xc/0x20 [ 370.463814] [<ffffffff801a5084>] __handle_irq_event_percpu+0xc4/0x1a8 [ 370.470404] [<ffffffff801a5188>] handle_irq_event_percpu+0x20/0x68 [ 370.476734] [<ffffffff801a521c>] handle_irq_event+0x4c/0x88 [ 370.482486] [<ffffffff801a8f84>] handle_edge_irq+0x12c/0x210 [ 370.488316] [<ffffffff801a47a0>] generic_handle_irq+0x38/0x48 [ 370.494280] [<ffffffff804a2dbc>] gic_handle_shared_int+0x194/0x268 [ 370.500616] [<ffffffff801a47a0>] generic_handle_irq+0x38/0x48 [ 370.506529] [<ffffffff80107e60>] do_IRQ+0x18/0x28 [ 370.511445] [<ffffffff804a1524>] plat_irq_dispatch+0xc4/0x140 [ 370.517339] [<ffffffff80106230>] ret_from_irq+0x0/0x4 [ 370.522583] [<ffffffff8010fad4>] do_ri+0x4fc/0x7e8 [ 370.527546] [<ffffffff80106220>] ret_from_exception+0x0/0x10 2) The IPI may arrive during kernel use of the FPU, since we generally only disable preemption around use of the FPU & leave interrupts enabled. This can lead to us unexpectedly losing access to the FPU in places where it previously had not been possible. For example: do_cpu invoked from kernel context![#2]: CPU: 2 PID: 7338 Comm: fp-prctl Tainted: G D 4.7.0-00424-g49b0c82 #2 task: 838e4000 ti: 88d38000 task.ti: 88d38000 $ 0 : 00000000 00000001 ffffffff 88d3fef8 $ 4 : 838e4000 88d38004 00000000 00000001 $ 8 : 3400fc01 801f8020 808e9100 24000000 $12 : dbffffff 807b69d8 807b0000 00000000 $16 : 00000000 80786150 00400fc4 809c0398 $20 : 809c0338 0040273c 88d3ff28 808e9d30 $24 : 808e9d30 00400fb4 $28 : 88d38000 88d3fe88 00000000 8011a2ac Hi : 0040273c Lo : 88d3ff28 epc : 80114178 _restore_fp+0x10/0xa0 ra : 8011a2ac mipsr2_decoder+0xd5c/0x1660 Status: 1400fc03 KERNEL EXL IE Cause : 1080002c (ExcCode 0b) PrId : 0001a920 (MIPS I6400) Modules linked in: Process fp-prctl (pid: 7338, threadinfo=88d38000, task=838e4000, tls=766527d0) Stack : 00000000 00000000 00000000 88d3fe98 00000000 00000000 809c0398 809c0338 808e9100 00000000 88d3ff28 00400fc4 00400fc4 0040273c 7fb69e18 004a0000 004a0000 004a0000 7664add0 8010de18 00000000 00000000 88d3fef8 88d3ff28 808e9100 00000000 766527d0 8010e534 000c0000 85755000 8181d580 00000000 00000000 00000000 004a0000 00000000 766527d0 7fb69e18 004a0000 80105c20 ... Call Trace: [<80114178>] _restore_fp+0x10/0xa0 [<8011a2ac>] mipsr2_decoder+0xd5c/0x1660 [<8010de18>] do_ri+0x90/0x6b8 [<80105c20>] ret_from_exception+0x0/0x10 At first glance a simple fix may seem to be to disable interrupts around kernel use of the FPU rather than merely preemption, however this would introduce further overhead outside of the mode switch path & doesn't solve the third problem: 3) The IPI may arrive whilst the kernel is running code that will lead to a preempt_disable() call & FPU usage soon. If this happens then the IPI will be serviced & we'll proceed to enable an FPU whilst the mode switch is in progress, leading to strange & inconsistent behaviour. Further to all of this is a separate but related problem: 4) There are various paths through which we may enable the FPU without the user having triggered a coprocessor 1 disabled exception. These paths are those in which we emulate instructions & then enable the FPU with the expectation that the user might execute an FP instruction shortly afterwards. However these paths have not previously checked whether an FP mode switch is underway for the task, and therefore could enable the FPU whilst such a mode switch is in progress leading to strange & inconsistent behaviour for user code. This patch fixes all of the above by taking a step back & re-examining our approach to FP mode switches. Up until now we have taken these basic steps: a) Prevent any threads that are part of the affected process from being able to obtain ownership of the FPU. b) Cause any threads that are part of the affected process and already have ownership of an FPU to lose it. c) Set the thread flags for each thread that is part of the affected process to reflect the new FP mode. d) Allow threads to obtain ownership of the FPU again. This approach is however more complex than necessary. All that we really require is that the mode switch has occurred for all threads that are part of the affected process before mips_set_process_fp_mode(), and thus the PR_SET_FP_MODE prctl() syscall, returns. This doesn't require that we stop threads from owning or using an FPU whilst a mode switch occurs, only that we force them to relinquish it after the mode switch has occurred such that they next own an FPU with the correct mode configured. Our basic steps therefore simplify to: A) Set the thread flags for each thread that is part of the affected process to reflect the new FP mode. B) Cause any threads that are part of the affected process and already have ownership of an FPU to lose it. We implement B) by forcing each CPU which might be running a thread which is part of the affected process to schedule a no-op function, which causes the affected thread to lose its FPU ownership when it is descheduled. The end result is simpler FP mode switching with less overhead in the FPU enable path (ie. enable_restore_fp_context()) and fewer moving parts. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: 9791554b45a2 ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS") Fixes: 6b8322576e9d ("MIPS: Force CPUs to lose FP context during mode switches") Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: stable <stable@vger.kernel.org> # v4.0+
2018-06-24MIPS: remove unneeded includes from dma-mapping.hChristoph Hellwig
Keep this file as light as possible as it gets pulled into every driver using dma mapping APIs. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19552/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: remove the old dma-default implementationChristoph Hellwig
Now unused. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19551/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: bmips: use generic dma noncoherent opsChristoph Hellwig
Provide phys_to_dma/dma_to_phys helpers, and the special arch_sync_dma_for_cpu_all hook, everything else is generic Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19550/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: jazz: split dma mapping operations from dma-defaultChristoph Hellwig
Jazz actually has a very basic IOMMU, so split the ops into a separate implementation from the generic default support (which is about to go away anyway). Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19548/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: ath25: use generic dma noncoherent opsChristoph Hellwig
Provide phys_to_dma/dma_to_phys helpers only if PCI support is enabled, everything else is generic. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19547/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: IP32: use generic dma noncoherent opsChristoph Hellwig
Provide phys_to_dma/dma_to_phys helpers, everything else is generic. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19546/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: loongson64: use generic dma noncoherent opsChristoph Hellwig
Provide phys_to_dma/dma_to_phys helpers, everything else is generic. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19545/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: use generic dma noncoherent ops for simple noncoherent platformsChristoph Hellwig
Convert everything not overriding dma-coherence.h to the generic noncoherent ops. The new dma-noncoherent.c file duplicates a lot of the code in dma-default.c, but that file will be gone by the end of this series. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19544/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: IP27: use dma_direct_opsChristoph Hellwig
IP27 is coherent and has a reasonably direct mapping, just with a little per-bus offset added into the dma address. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19542/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: use dma_direct_ops for coherent I/OChristoph Hellwig
Switch the simple cache coherent architectures that don't require any DMA address translation to dma_direct_ops. We'll soon use at least parts of the direct DMA ops implementation for all platforms, so select the symbol globally. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19540/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: loongson: remove loongson-3 handling from dma-coherence.hChristoph Hellwig
Loongson3 is dma coherent and uses swiotlb, so it will never used any of these helpers. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19541/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: Octeon: move swiotlb declarations out of dma-coherence.hChristoph Hellwig
No need to pull them into a global header. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19538/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: Octeon: remove mips dma-default stubsChristoph Hellwig
Octeon doesn't use the dma-default code, and now doesn't built it either, so these stubs can be removed. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19537/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: make the default mips dma implementation optionalChristoph Hellwig
Octeon and loonson64 already don't use it at all, and we're going to migrate more plaforms away from it. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19536/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: remove the mips_dma_map_ops indirectionChristoph Hellwig
And use mips_default_dma_map_ops directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19535/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: consolidate the swiotlb implementationsChristoph Hellwig
Octeon and Loongson share exactly the same code, move it into a common implementation, and use that implementation directly from get_arch_dma_ops. Also provide the expected dma-direct.h helpers directly instead of delegating to platform dma-coherence.h headers. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19534/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: Octeon: refactor swiotlb codeChristoph Hellwig
Share a common set of swiotlb operations, and to instead branch out in __phys_to_dma/__dma_to_phys for the PCI vs non-PCI case. Also use const structures for the PCI methods so that attackers can't use them as exploit vectors. Signed-off-by: Christoph Hellwig <hch@lst.de> Patchwork: https://patchwork.linux-mips.org/patch/19532/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: remove CONFIG_DMA_COHERENTChristoph Hellwig
We can just check for !CONFIG_DMA_NONCOHERENT instead and simplify things a lot. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19530/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: simplify CONFIG_DMA_NONCOHERENT ifdefsChristoph Hellwig
CONFIG_DMA_MAYBE_COHERENT already selects CONFIG_DMA_NONCOHERENT, so we can remove the extra conditions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19529/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-24MIPS: remove a dead ifdef from mach-ath25/dma-coherence.hChristoph Hellwig
ath25 is alwas non-coherent, so keeping these ifdefs doesn't make any sense. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19528/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org
2018-06-21atomics/treewide: Make unconditional inc/dec ops optionalMark Rutland
Many of the inc/dec ops are mandatory, but for most architectures inc/dec are simply trivial wrappers around their corresponding add/sub ops. Let's make all the inc/dec ops optional, so that we can get rid of these boilerplate wrappers. The instrumented atomics are updated accordingly. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-17-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21atomics/treewide: Make test ops optionalMark Rutland
Some of the atomics return the result of a test applied after the atomic operation, and almost all architectures implement these as trivial wrappers around the underlying atomic. Specifically: * <atomic>_inc_and_test(v) is (<atomic>_inc_return(v) == 0) * <atomic>_dec_and_test(v) is (<atomic>_dec_return(v) == 0) * <atomic>_sub_and_test(i, v) is (<atomic>_sub_return(i, v) == 0) * <atomic>_add_negative(i, v) is (<atomic>_add_return(i, v) < 0) Rather than have these definitions duplicated in all architectures, with minor inconsistencies in formatting and documentation, let's make these operations optional, with default fallbacks as above. Implementations must now provide a preprocessor symbol. The instrumented atomics are updated accordingly. Both x86 and m68k have custom implementations, which are left as-is, given preprocessor symbols to avoid being overridden. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-16-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21atomics/treewide: Make atomic64_fetch_add_unless() optionalMark Rutland
Architectures with atomic64_fetch_add_unless() provide a preprocessor symbol if they do so, and all other architectures have trivial C implementations of atomic64_add_unless() which are near-identical. Let's unify the trivial definitions of atomic64_fetch_add_unless() in <linux/atomic.h>, so that we always have both atomic64_fetch_add_unless() and atomic64_add_unless() with less boilerplate code. This means that atomic64_add_unless() is always implemented in core code, and the instrumented atomics are updated accordingly. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-15-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21atomics/treewide: Make atomic_fetch_add_unless() optionalMark Rutland
Several architectures these have a near-identical implementation based on atomic_read() and atomic_cmpxchg() which we can instead define in <linux/atomic.h>, so let's do so, using something close to the existing x86 implementation with try_cmpxchg(). Where an architecture provides its own atomic_fetch_add_unless(), it must define a preprocessor symbol for it. The instrumented atomics are updated accordingly. Note that arch/arc's existing atomic_fetch_add_unless() had redundant barriers, as these are already present in its atomic_cmpxchg() implementation. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineet Gupta <vgupta@synopsys.com> Link: https://lore.kernel.org/lkml/20180621121321.4761-7-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>