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e62dff0df4
The rule of thumb is to include the headers we are the direct user of. In particular, if we need an atomic API, we include <linux/atomic.h>. On the other hand we should not use headers for no reason. In particular, if we are not doing any IRQ job, why is the <linux/irq.h> included? Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
56 lines
1010 B
C
56 lines
1010 B
C
/*
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* example_rwlock.c
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/rwlock.h>
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static DEFINE_RWLOCK(myrwlock);
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static void example_read_lock(void)
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{
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unsigned long flags;
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read_lock_irqsave(&myrwlock, flags);
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pr_info("Read Locked\n");
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/* Read from something */
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read_unlock_irqrestore(&myrwlock, flags);
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pr_info("Read Unlocked\n");
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}
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static void example_write_lock(void)
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{
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unsigned long flags;
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write_lock_irqsave(&myrwlock, flags);
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pr_info("Write Locked\n");
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/* Write to something */
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write_unlock_irqrestore(&myrwlock, flags);
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pr_info("Write Unlocked\n");
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}
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static int example_rwlock_init(void)
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{
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pr_info("example_rwlock started\n");
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example_read_lock();
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example_write_lock();
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return 0;
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}
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static void example_rwlock_exit(void)
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{
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pr_info("example_rwlock exit\n");
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}
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module_init(example_rwlock_init);
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module_exit(example_rwlock_exit);
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MODULE_DESCRIPTION("Read/Write locks example");
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MODULE_LICENSE("GPL");
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