64 lines
1.4 KiB
C
64 lines
1.4 KiB
C
#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/interrupt.h>
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DEFINE_SPINLOCK(sl_static);
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spinlock_t sl_dynamic;
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static void example_spinlock_static(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&sl_static, flags);
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pr_info("Locked static spinlock\n");
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/* Do something or other safely.
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Because this uses 100% CPU time this
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code should take no more than a few
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milliseconds to run */
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spin_unlock_irqrestore(&sl_static, flags);
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pr_info("Unlocked static spinlock\n");
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}
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static void example_spinlock_dynamic(void)
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{
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unsigned long flags;
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spin_lock_init(&sl_dynamic);
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spin_lock_irqsave(&sl_dynamic, flags);
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pr_info("Locked dynamic spinlock\n");
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/* Do something or other safely.
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Because this uses 100% CPU time this
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code should take no more than a few
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milliseconds to run */
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spin_unlock_irqrestore(&sl_dynamic, flags);
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pr_info("Unlocked dynamic spinlock\n");
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}
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static int example_spinlock_init(void)
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{
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pr_info("example spinlock started\n");
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example_spinlock_static();
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example_spinlock_dynamic();
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return 0;
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}
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static void example_spinlock_exit(void)
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{
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pr_info("example spinlock exit\n");
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}
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module_init(example_spinlock_init);
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module_exit(example_spinlock_exit);
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MODULE_AUTHOR("Bob Mottram");
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MODULE_DESCRIPTION("Spinlock example");
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MODULE_LICENSE("GPL");
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