linux-dev/arch/csky/kernel/smp.c, branch linus/master

csky: Use of_get_cpu_hwid()

2021-10-20T18:37:24Z

Replace open coded parsing of CPU nodes 'reg' property with of_get_cpu_hwid(). Cc: Guo Ren Cc: linux-csky@vger.kernel.org Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/20211006164332.1981454-6-robh@kernel.org

sched/core: Initialize the idle task with preemption disabled

2021-05-12T11:01:45Z

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

csky: Add memory layout 2.5G(user):1.5G(kernel)

2021-01-12T01:52:40Z

There are two ways for translating va to pa for csky: - Use TLB(Translate Lookup Buffer) and PTW (Page Table Walk) - Use SSEG0/1 (Simple Segment Mapping) We use tlb mapping 0-2G and 3G-4G virtual address area and SSEG0/1 are for 2G-2.5G and 2.5G-3G translation. We could disable SSEG0 to use 2G-2.5G as TLB user mapping. Signed-off-by: Guo Ren

mm: remove unneeded includes of

2020-08-07T18:33:26Z

Patch series "mm: cleanup usage of " Most architectures have very similar versions of pXd_alloc_one() and pXd_free_one() for intermediate levels of page table. These patches add generic versions of these functions in and enable use of the generic functions where appropriate. In addition, functions declared and defined in headers are used mostly by core mm and early mm initialization in arch and there is no actual reason to have the included all over the place. The first patch in this series removes unneeded includes of In the end it didn't work out as neatly as I hoped and moving pXd_alloc_track() definitions to would require unnecessary changes to arches that have custom page table allocations, so I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local to mm/. This patch (of 8): In most cases header is required only for allocations of page table memory. Most of the .c files that include that header do not use symbols declared in and do not require that header. As for the other header files that used to include , it is possible to move that include into the .c file that actually uses symbols from and drop the include from the header file. The process was somewhat automated using sed -i -E '/[<"]asm\/pgalloc\.h/d' \ $(grep -L -w -f /tmp/xx \ $(git grep -E -l '[<"]asm/pgalloc\.h')) where /tmp/xx contains all the symbols defined in arch/*/include/asm/pgalloc.h. [rppt@linux.ibm.com: fix powerpc warning] Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Reviewed-by: Pekka Enberg Acked-by: Geert Uytterhoeven [m68k] Cc: Abdul Haleem Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Christophe Leroy Cc: Joerg Roedel Cc: Max Filippov Cc: Peter Zijlstra Cc: Satheesh Rajendran Cc: Stafford Horne Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Joerg Roedel Cc: Matthew Wilcox Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org Signed-off-by: Linus Torvalds

csky: Add arch_show_interrupts for IPI interrupts

2020-07-31T01:56:01Z

Here is the result: cat /proc/interrupts CPU0 CPU1 CPU2 CPU3 15: 1348 1299 952 1076 C-SKY SMP Intc 15 IPI Interrupt 16: 1203 1825 1598 1307 C-SKY SMP Intc 16 csky_mp_timer 43: 292 0 0 0 C-SKY SMP Intc 43 ttyS0 57: 106 0 0 0 C-SKY SMP Intc 57 virtio0 IPI0: 0 0 0 0 Empty interrupts IPI1: 19 41 45 27 Rescheduling interrupts IPI2: 1330 1259 908 1050 Function call interrupts IPI3: 0 0 0 0 Irq work interrupts Signed-off-by: Guo Ren Cc: Arnd Bergmann

csky: Add irq_work support

2020-07-31T01:55:46Z

Running work in hardware interrupt context for csky. Implement: - arch_irq_work_raise() - arch_irq_work_has_interrupt() Signed-off-by: Guo Ren Cc: Arnd Bergmann

csky: Add cpu feature register hint for smp

2020-07-31T01:51:29Z

CPU features registers are setup by customers' bootloader, but Linux must help transfer them from the primary to secondary cores. This patch add hint2 CPU feature register supported. Signed-off-by: Guo Ren Cc: Arnd Bergmann

csky: Fixup cpu speculative execution to IO area

2020-04-03T04:40:07Z

For the memory size ( > 512MB, < 1GB), the MSA setting is: - SSEG0: PHY_START , PHY_START + 512MB - SSEG1: PHY_START + 512MB, PHY_START + 1GB But the real memory is no more than 1GB, there is a gap between the end size of memory and border of 1GB. CPU could speculatively execute to that gap and if the gap of the bus couldn't respond to the CPU request, then the crash will happen. Now make the setting with: - SSEG0: PHY_START , PHY_START + 512MB (no change) - SSEG1: Disabled (We use highmem to use the memory of 512MB~1GB) We also deprecated zhole_szie[] settings, it's only used by arm style CPUs. All memory gap should use Reserved setting of dts in csky system. Signed-off-by: Guo Ren

csky: Fixup init_fpu compile warning with __init

2020-03-08T12:55:14Z

WARNING: vmlinux.o(.text+0x2366): Section mismatch in reference from the function csky_start_secondary() to the function .init.text:init_fpu() The function csky_start_secondary() references the function __init init_fpu(). This is often because csky_start_secondary lacks a __init annotation or the annotation of init_fpu is wrong. Reported-by: Lu Chongzhi Signed-off-by: Guo Ren

csky/smp: Fixup boot failed when CONFIG_SMP

2020-02-21T07:43:24Z

If we use a non-ipi-support interrupt controller, it will cause panic here. We should let cpu up and work with CONFIG_SMP, when we use a non-ipi intc. Signed-off-by: Guo Ren