![Tejun Heo](/assets/img/avatar_default.png)
percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
472 lines
11 KiB
C
472 lines
11 KiB
C
/*
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** SMP Support
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**
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** Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
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** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
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** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org>
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**
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** Lots of stuff stolen from arch/alpha/kernel/smp.c
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** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)
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**
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** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work.
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** -grant (1/12/2001)
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**
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** This program is free software; you can redistribute it and/or modify
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** it under the terms of the GNU General Public License as published by
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** the Free Software Foundation; either version 2 of the License, or
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** (at your option) any later version.
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*/
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#include <linux/types.h>
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#include <linux/spinlock.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/smp.h>
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#include <linux/kernel_stat.h>
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#include <linux/mm.h>
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#include <linux/err.h>
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#include <linux/delay.h>
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#include <linux/bitops.h>
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#include <linux/ftrace.h>
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#include <asm/system.h>
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#include <asm/atomic.h>
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#include <asm/current.h>
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#include <asm/delay.h>
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#include <asm/tlbflush.h>
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#include <asm/io.h>
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#include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
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#include <asm/mmu_context.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/processor.h>
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#include <asm/ptrace.h>
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#include <asm/unistd.h>
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#include <asm/cacheflush.h>
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#undef DEBUG_SMP
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#ifdef DEBUG_SMP
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static int smp_debug_lvl = 0;
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#define smp_debug(lvl, printargs...) \
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if (lvl >= smp_debug_lvl) \
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printk(printargs);
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#else
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#define smp_debug(lvl, ...) do { } while(0)
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#endif /* DEBUG_SMP */
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volatile struct task_struct *smp_init_current_idle_task;
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/* track which CPU is booting */
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static volatile int cpu_now_booting __cpuinitdata;
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static int parisc_max_cpus __cpuinitdata = 1;
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static DEFINE_PER_CPU(spinlock_t, ipi_lock);
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enum ipi_message_type {
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IPI_NOP=0,
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IPI_RESCHEDULE=1,
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IPI_CALL_FUNC,
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IPI_CALL_FUNC_SINGLE,
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IPI_CPU_START,
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IPI_CPU_STOP,
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IPI_CPU_TEST
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};
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/********** SMP inter processor interrupt and communication routines */
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#undef PER_CPU_IRQ_REGION
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#ifdef PER_CPU_IRQ_REGION
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/* XXX REVISIT Ignore for now.
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** *May* need this "hook" to register IPI handler
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** once we have perCPU ExtIntr switch tables.
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*/
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static void
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ipi_init(int cpuid)
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{
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#error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
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if(cpu_online(cpuid) )
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{
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switch_to_idle_task(current);
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}
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return;
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}
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#endif
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/*
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** Yoink this CPU from the runnable list...
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**
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*/
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static void
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halt_processor(void)
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{
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/* REVISIT : redirect I/O Interrupts to another CPU? */
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/* REVISIT : does PM *know* this CPU isn't available? */
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set_cpu_online(smp_processor_id(), false);
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local_irq_disable();
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for (;;)
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;
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}
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irqreturn_t __irq_entry
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ipi_interrupt(int irq, void *dev_id)
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{
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int this_cpu = smp_processor_id();
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struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu);
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unsigned long ops;
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unsigned long flags;
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/* Count this now; we may make a call that never returns. */
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p->ipi_count++;
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mb(); /* Order interrupt and bit testing. */
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for (;;) {
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spinlock_t *lock = &per_cpu(ipi_lock, this_cpu);
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spin_lock_irqsave(lock, flags);
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ops = p->pending_ipi;
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p->pending_ipi = 0;
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spin_unlock_irqrestore(lock, flags);
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mb(); /* Order bit clearing and data access. */
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if (!ops)
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break;
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while (ops) {
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unsigned long which = ffz(~ops);
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ops &= ~(1 << which);
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switch (which) {
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case IPI_NOP:
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smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu);
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break;
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case IPI_RESCHEDULE:
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smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
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/*
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* Reschedule callback. Everything to be
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* done is done by the interrupt return path.
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*/
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break;
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case IPI_CALL_FUNC:
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smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
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generic_smp_call_function_interrupt();
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break;
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case IPI_CALL_FUNC_SINGLE:
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smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC_SINGLE\n", this_cpu);
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generic_smp_call_function_single_interrupt();
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break;
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case IPI_CPU_START:
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smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu);
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break;
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case IPI_CPU_STOP:
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smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu);
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halt_processor();
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break;
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case IPI_CPU_TEST:
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smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
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break;
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default:
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printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
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this_cpu, which);
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return IRQ_NONE;
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} /* Switch */
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/* let in any pending interrupts */
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local_irq_enable();
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local_irq_disable();
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} /* while (ops) */
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}
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return IRQ_HANDLED;
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}
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static inline void
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ipi_send(int cpu, enum ipi_message_type op)
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{
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struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu);
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spinlock_t *lock = &per_cpu(ipi_lock, cpu);
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unsigned long flags;
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spin_lock_irqsave(lock, flags);
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p->pending_ipi |= 1 << op;
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gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa);
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spin_unlock_irqrestore(lock, flags);
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}
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static void
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send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op)
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{
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int cpu;
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for_each_cpu(cpu, mask)
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ipi_send(cpu, op);
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}
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static inline void
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send_IPI_single(int dest_cpu, enum ipi_message_type op)
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{
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BUG_ON(dest_cpu == NO_PROC_ID);
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ipi_send(dest_cpu, op);
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}
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static inline void
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send_IPI_allbutself(enum ipi_message_type op)
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{
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int i;
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for_each_online_cpu(i) {
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if (i != smp_processor_id())
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send_IPI_single(i, op);
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}
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}
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inline void
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smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
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static inline void
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smp_send_start(void) { send_IPI_allbutself(IPI_CPU_START); }
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void
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smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
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void
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smp_send_all_nop(void)
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{
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send_IPI_allbutself(IPI_NOP);
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}
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void arch_send_call_function_ipi_mask(const struct cpumask *mask)
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{
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send_IPI_mask(mask, IPI_CALL_FUNC);
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}
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void arch_send_call_function_single_ipi(int cpu)
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{
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send_IPI_single(cpu, IPI_CALL_FUNC_SINGLE);
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}
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/*
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* Flush all other CPU's tlb and then mine. Do this with on_each_cpu()
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* as we want to ensure all TLB's flushed before proceeding.
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*/
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void
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smp_flush_tlb_all(void)
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{
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on_each_cpu(flush_tlb_all_local, NULL, 1);
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}
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/*
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* Called by secondaries to update state and initialize CPU registers.
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*/
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static void __init
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smp_cpu_init(int cpunum)
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{
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extern int init_per_cpu(int); /* arch/parisc/kernel/processor.c */
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extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
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extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
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/* Set modes and Enable floating point coprocessor */
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(void) init_per_cpu(cpunum);
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disable_sr_hashing();
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mb();
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/* Well, support 2.4 linux scheme as well. */
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if (cpu_isset(cpunum, cpu_online_map))
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{
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extern void machine_halt(void); /* arch/parisc.../process.c */
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printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
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machine_halt();
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}
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set_cpu_online(cpunum, true);
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/* Initialise the idle task for this CPU */
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atomic_inc(&init_mm.mm_count);
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current->active_mm = &init_mm;
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BUG_ON(current->mm);
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enter_lazy_tlb(&init_mm, current);
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init_IRQ(); /* make sure no IRQs are enabled or pending */
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start_cpu_itimer();
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}
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/*
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* Slaves start using C here. Indirectly called from smp_slave_stext.
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* Do what start_kernel() and main() do for boot strap processor (aka monarch)
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*/
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void __init smp_callin(void)
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{
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int slave_id = cpu_now_booting;
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smp_cpu_init(slave_id);
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preempt_disable();
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flush_cache_all_local(); /* start with known state */
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flush_tlb_all_local(NULL);
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local_irq_enable(); /* Interrupts have been off until now */
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cpu_idle(); /* Wait for timer to schedule some work */
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/* NOTREACHED */
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panic("smp_callin() AAAAaaaaahhhh....\n");
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}
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/*
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* Bring one cpu online.
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*/
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int __cpuinit smp_boot_one_cpu(int cpuid)
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{
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const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
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struct task_struct *idle;
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long timeout;
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/*
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* Create an idle task for this CPU. Note the address wed* give
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* to kernel_thread is irrelevant -- it's going to start
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* where OS_BOOT_RENDEVZ vector in SAL says to start. But
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* this gets all the other task-y sort of data structures set
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* up like we wish. We need to pull the just created idle task
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* off the run queue and stuff it into the init_tasks[] array.
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* Sheesh . . .
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*/
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idle = fork_idle(cpuid);
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if (IS_ERR(idle))
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panic("SMP: fork failed for CPU:%d", cpuid);
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task_thread_info(idle)->cpu = cpuid;
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/* Let _start know what logical CPU we're booting
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** (offset into init_tasks[],cpu_data[])
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*/
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cpu_now_booting = cpuid;
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/*
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** boot strap code needs to know the task address since
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** it also contains the process stack.
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*/
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smp_init_current_idle_task = idle ;
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mb();
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printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa);
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/*
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** This gets PDC to release the CPU from a very tight loop.
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**
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** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
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** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
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** is executed after receiving the rendezvous signal (an interrupt to
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** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
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** contents of memory are valid."
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*/
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gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa);
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mb();
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/*
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* OK, wait a bit for that CPU to finish staggering about.
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* Slave will set a bit when it reaches smp_cpu_init().
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* Once the "monarch CPU" sees the bit change, it can move on.
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*/
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for (timeout = 0; timeout < 10000; timeout++) {
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if(cpu_online(cpuid)) {
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/* Which implies Slave has started up */
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cpu_now_booting = 0;
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smp_init_current_idle_task = NULL;
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goto alive ;
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}
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udelay(100);
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barrier();
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}
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put_task_struct(idle);
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idle = NULL;
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printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
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return -1;
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alive:
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/* Remember the Slave data */
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smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
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cpuid, timeout * 100);
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return 0;
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}
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void __init smp_prepare_boot_cpu(void)
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{
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int bootstrap_processor = per_cpu(cpu_data, 0).cpuid;
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/* Setup BSP mappings */
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printk(KERN_INFO "SMP: bootstrap CPU ID is %d\n", bootstrap_processor);
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set_cpu_online(bootstrap_processor, true);
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set_cpu_present(bootstrap_processor, true);
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}
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/*
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** inventory.c:do_inventory() hasn't yet been run and thus we
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** don't 'discover' the additional CPUs until later.
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*/
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void __init smp_prepare_cpus(unsigned int max_cpus)
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{
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int cpu;
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for_each_possible_cpu(cpu)
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spin_lock_init(&per_cpu(ipi_lock, cpu));
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init_cpu_present(cpumask_of(0));
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parisc_max_cpus = max_cpus;
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if (!max_cpus)
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printk(KERN_INFO "SMP mode deactivated.\n");
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}
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void smp_cpus_done(unsigned int cpu_max)
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{
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return;
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}
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int __cpuinit __cpu_up(unsigned int cpu)
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{
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if (cpu != 0 && cpu < parisc_max_cpus)
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smp_boot_one_cpu(cpu);
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return cpu_online(cpu) ? 0 : -ENOSYS;
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}
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#ifdef CONFIG_PROC_FS
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int __init
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setup_profiling_timer(unsigned int multiplier)
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{
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return -EINVAL;
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}
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#endif
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