forked from mirrors/linux
		
	Add SPDX license identifiers to all files which:
 - Have no license information of any form
 - Have MODULE_LICENCE("GPL*") inside which was used in the initial
   scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
  GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
		
	
			
		
			
				
	
	
		
			139 lines
		
	
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			139 lines
		
	
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/module.h>
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/* validate @native and @pcp counter values match @expected */
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#define CHECK(native, pcp, expected)                                    \
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	do {                                                            \
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		WARN((native) != (expected),                            \
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		     "raw %ld (0x%lx) != expected %lld (0x%llx)",	\
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		     (native), (native),				\
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		     (long long)(expected), (long long)(expected));	\
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		WARN(__this_cpu_read(pcp) != (expected),                \
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		     "pcp %ld (0x%lx) != expected %lld (0x%llx)",	\
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		     __this_cpu_read(pcp), __this_cpu_read(pcp),	\
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		     (long long)(expected), (long long)(expected));	\
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	} while (0)
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static DEFINE_PER_CPU(long, long_counter);
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static DEFINE_PER_CPU(unsigned long, ulong_counter);
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static int __init percpu_test_init(void)
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{
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	/*
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	 * volatile prevents compiler from optimizing it uses, otherwise the
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	 * +ul_one/-ul_one below would replace with inc/dec instructions.
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	 */
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	volatile unsigned int ui_one = 1;
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	long l = 0;
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	unsigned long ul = 0;
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	pr_info("percpu test start\n");
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	preempt_disable();
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	l += -1;
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	__this_cpu_add(long_counter, -1);
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	CHECK(l, long_counter, -1);
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	l += 1;
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	__this_cpu_add(long_counter, 1);
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	CHECK(l, long_counter, 0);
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	ul = 0;
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	__this_cpu_write(ulong_counter, 0);
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	ul += 1UL;
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	__this_cpu_add(ulong_counter, 1UL);
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	CHECK(ul, ulong_counter, 1);
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	ul += -1UL;
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	__this_cpu_add(ulong_counter, -1UL);
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	CHECK(ul, ulong_counter, 0);
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	ul += -(unsigned long)1;
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	__this_cpu_add(ulong_counter, -(unsigned long)1);
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	CHECK(ul, ulong_counter, -1);
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	ul = 0;
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	__this_cpu_write(ulong_counter, 0);
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	ul -= 1;
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	__this_cpu_dec(ulong_counter);
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	CHECK(ul, ulong_counter, -1);
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	CHECK(ul, ulong_counter, ULONG_MAX);
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	l += -ui_one;
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	__this_cpu_add(long_counter, -ui_one);
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	CHECK(l, long_counter, 0xffffffff);
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	l += ui_one;
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	__this_cpu_add(long_counter, ui_one);
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	CHECK(l, long_counter, (long)0x100000000LL);
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	l = 0;
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	__this_cpu_write(long_counter, 0);
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	l -= ui_one;
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	__this_cpu_sub(long_counter, ui_one);
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	CHECK(l, long_counter, -1);
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	l = 0;
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	__this_cpu_write(long_counter, 0);
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	l += ui_one;
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	__this_cpu_add(long_counter, ui_one);
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	CHECK(l, long_counter, 1);
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	l += -ui_one;
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	__this_cpu_add(long_counter, -ui_one);
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	CHECK(l, long_counter, (long)0x100000000LL);
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	l = 0;
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	__this_cpu_write(long_counter, 0);
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	l -= ui_one;
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	this_cpu_sub(long_counter, ui_one);
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	CHECK(l, long_counter, -1);
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	CHECK(l, long_counter, ULONG_MAX);
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	ul = 0;
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	__this_cpu_write(ulong_counter, 0);
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	ul += ui_one;
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	__this_cpu_add(ulong_counter, ui_one);
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	CHECK(ul, ulong_counter, 1);
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	ul = 0;
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	__this_cpu_write(ulong_counter, 0);
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	ul -= ui_one;
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	__this_cpu_sub(ulong_counter, ui_one);
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	CHECK(ul, ulong_counter, -1);
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	CHECK(ul, ulong_counter, ULONG_MAX);
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	ul = 3;
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	__this_cpu_write(ulong_counter, 3);
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	ul = this_cpu_sub_return(ulong_counter, ui_one);
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	CHECK(ul, ulong_counter, 2);
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	ul = __this_cpu_sub_return(ulong_counter, ui_one);
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	CHECK(ul, ulong_counter, 1);
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	preempt_enable();
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	pr_info("percpu test done\n");
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	return -EAGAIN;  /* Fail will directly unload the module */
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}
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static void __exit percpu_test_exit(void)
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{
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}
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module_init(percpu_test_init)
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module_exit(percpu_test_exit)
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Greg Thelen");
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MODULE_DESCRIPTION("percpu operations test");
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