kernel/git/stable/linux.git/arch/openrisc, branch linux-5.12.y

sched/core: Initialize the idle task with preemption disabled

2021-07-14T14:59:16+00:00

[ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ] As pointed out by commit de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread") init_idle() can and will be invoked more than once on the same idle task. At boot time, it is invoked for the boot CPU thread by sched_init(). Then smp_init() creates the threads for all the secondary CPUs and invokes init_idle() on them. As the hotplug machinery brings the secondaries to life, it will issue calls to idle_thread_get(), which itself invokes init_idle() yet again. In this case it's invoked twice more per secondary: at _cpu_up(), and at bringup_cpu(). Given smp_init() already initializes the idle tasks for all *possible* CPUs, no further initialization should be required. Now, removing init_idle() from idle_thread_get() exposes some interesting expectations with regards to the idle task's preempt_count: the secondary startup always issues a preempt_disable(), requiring some reset of the preempt count to 0 between hot-unplug and hotplug, which is currently served by idle_thread_get() -> idle_init(). Given the idle task is supposed to have preemption disabled once and never see it re-enabled, it seems that what we actually want is to initialize its preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove init_idle() from idle_thread_get(). Secondary startups were patched via coccinelle: @begone@ @@ -preempt_disable(); ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); Signed-off-by: Valentin Schneider Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com Signed-off-by: Sasha Levin

openrisc: Define memory barrier mb

2021-06-03T07:09:42+00:00

[ Upstream commit 8b549c18ae81dbc36fb11e4aa08b8378c599ca95 ] This came up in the discussion of the requirements of qspinlock on an architecture. OpenRISC uses qspinlock, but it was noticed that the memmory barrier was not defined. Peter defined it in the mail thread writing: As near as I can tell this should do. The arch spec only lists this one instruction and the text makes it sound like a completion barrier. This is correct so applying this patch. Signed-off-by: Peter Zijlstra [shorne@gmail.com:Turned the mail into a patch] Signed-off-by: Stafford Horne Signed-off-by: Sasha Levin

openrisc: mm/init.c: remove unused memblock_region variable in map_ram()

2021-05-26T10:59:14+00:00

commit 4eff124347191d1548eb4e14e20e77513dcbd0fe upstream. Kernel test robot reports: cppcheck possible warnings: (new ones prefixed by >>, may not real problems) >> arch/openrisc/mm/init.c:125:10: warning: Uninitialized variable: region [uninitvar] region->base, region->base + region->size); ^ Replace usage of memblock_region fields with 'start' and 'end' variables that are initialized in for_each_mem_range() and remove the declaration of region. Fixes: b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()") Reported-by: kernel test robot Signed-off-by: Mike Rapoport Signed-off-by: Stafford Horne Signed-off-by: Greg Kroah-Hartman

openrisc: Fix a memory leak

2021-05-26T10:59:02+00:00

[ Upstream commit c019d92457826bb7b2091c86f36adb5de08405f9 ] 'setup_find_cpu_node()' take a reference on the node it returns. This reference must be decremented when not needed anymore, or there will be a leak. Add the missing 'of_node_put(cpu)'. Note that 'setup_cpuinfo()' that also calls this function already has a correct 'of_node_put(cpu)' at its end. Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Signed-off-by: Christophe JAILLET Signed-off-by: Stafford Horne Signed-off-by: Sasha Levin

Merge tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block

2021-02-27T16:29:02+00:00

Pull io_uring thread rewrite from Jens Axboe: "This converts the io-wq workers to be forked off the tasks in question instead of being kernel threads that assume various bits of the original task identity. This kills > 400 lines of code from io_uring/io-wq, and it's the worst part of the code. We've had several bugs in this area, and the worry is always that we could be missing some pieces for file types doing unusual things (recent /dev/tty example comes to mind, userfaultfd reads installing file descriptors is another fun one... - both of which need special handling, and I bet it's not the last weird oddity we'll find). With these identical workers, we can have full confidence that we're never missing anything. That, in itself, is a huge win. Outside of that, it's also more efficient since we're not wasting space and code on tracking state, or switching between different states. I'm sure we're going to find little things to patch up after this series, but testing has been pretty thorough, from the usual regression suite to production. Any issue that may crop up should be manageable. There's also a nice series of further reductions we can do on top of this, but I wanted to get the meat of it out sooner rather than later. The general worry here isn't that it's fundamentally broken. Most of the little issues we've found over the last week have been related to just changes in how thread startup/exit is done, since that's the main difference between using kthreads and these kinds of threads. In fact, if all goes according to plan, I want to get this into the 5.10 and 5.11 stable branches as well. That said, the changes outside of io_uring/io-wq are: - arch setup, simple one-liner to each arch copy_thread() implementation. - Removal of net and proc restrictions for io_uring, they are no longer needed or useful" * tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits) io-wq: remove now unused IO_WQ_BIT_ERROR io_uring: fix SQPOLL thread handling over exec io-wq: improve manager/worker handling over exec io_uring: ensure SQPOLL startup is triggered before error shutdown io-wq: make buffered file write hashed work map per-ctx io-wq: fix race around io_worker grabbing io-wq: fix races around manager/worker creation and task exit io_uring: ensure io-wq context is always destroyed for tasks arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread() io_uring: cleanup ->user usage io-wq: remove nr_process accounting io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS net: remove cmsg restriction from io_uring based send/recvmsg calls Revert "proc: don't allow async path resolution of /proc/self components" Revert "proc: don't allow async path resolution of /proc/thread-self components" io_uring: move SQPOLL thread io-wq forked worker io-wq: make io_wq_fork_thread() available to other users io-wq: only remove worker from free_list, if it was there io_uring: remove io_identity io_uring: remove any grabbing of context ...

arch: setup PF_IO_WORKER threads like PF_KTHREAD

2021-02-22T00:25:22+00:00

PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the sense that we don't assign ->set_child_tid with our own structure. Just ensure that every arch sets up the PF_IO_WORKER threads like kthreads in the arch implementation of copy_thread(). Signed-off-by: Jens Axboe

openrisc: Use devicetree to determine present cpus

2021-02-08T20:38:50+00:00

Use the device tree to determine the present cpus instead of assuming all CONFIG_NRCPUS are actually present in the system. Signed-off-by: Jan Henrik Weinstock [shorne: Squashed 2 email commits and added summary from email] Cc: Geert Uytterhoeven Signed-off-by: Stafford Horne

Merge remote-tracking branch 'openrisc/or1k-5.11-fixes' into or1k-5.12-updates

2021-01-25T02:16:06+00:00

Pickup fixes that went upstream already in order to resolve conflicts in litex_soc_ctrl.c between 5.11 fixes that went upstream and the or1k-5.12-updates linux-next queue. Signed-off-by: Stafford Horne

openrisc: io: Add missing __iomem annotation to iounmap()

2021-01-19T21:14:26+00:00

With C=1: drivers/soc/renesas/rmobile-sysc.c:330:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected void *addr @@ got void [noderef] __iomem *[assigned] base @@ drivers/soc/renesas/rmobile-sysc.c:330:33: sparse: expected void *addr drivers/soc/renesas/rmobile-sysc.c:330:33: sparse: got void [noderef] __iomem *[assigned] base Fix this by adding the missing __iomem annotation to iounmap(). Reported-by: kernel test robot Signed-off-by: Geert Uytterhoeven Signed-off-by: Stafford Horne

openrisc: add arch/openrisc/Kbuild

2021-01-18T11:53:14+00:00

Describe the subdirectories under arch/openrisc/ in arch/openrisc/Kbuild so you can use the standard obj-y syntax. I removed the CONFIG_OPENRISC_BUILTIN_DTB conditional because it is already controlled by arch/openrisc/boot/dts/Makefile. Signed-off-by: Masahiro Yamada Signed-off-by: Stafford Horne