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	Exercise the new __sg_alloc_table_from_pages API (and through it also the old sg_alloc_table_from_pages), checking that the created table has the expected number of segments depending on the sequence of input pages and other conditions. v2: Move to data driven for readability. v3: Add some more testcases and -fsanitize=undefined. (Chris Wilson) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: linux-kernel@vger.kernel.org Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/20170906145506.14952-1-tvrtko.ursulin@linux.intel.com [tursulin: whitespace fixup]
		
			
				
	
	
		
			79 lines
		
	
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			79 lines
		
	
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#include <stdio.h>
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#include <assert.h>
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#include <linux/scatterlist.h>
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#define MAX_PAGES (64)
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static void set_pages(struct page **pages, const unsigned *array, unsigned num)
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{
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	unsigned int i;
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	assert(num < MAX_PAGES);
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	for (i = 0; i < num; i++)
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		pages[i] = (struct page *)(unsigned long)
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			   ((1 + array[i]) * PAGE_SIZE);
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}
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#define pfn(...) (unsigned []){ __VA_ARGS__ }
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int main(void)
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{
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	const unsigned int sgmax = SCATTERLIST_MAX_SEGMENT;
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	struct test {
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		int alloc_ret;
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		unsigned num_pages;
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		unsigned *pfn;
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		unsigned size;
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		unsigned int max_seg;
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		unsigned int expected_segments;
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	} *test, tests[] = {
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		{ -EINVAL, 1, pfn(0), PAGE_SIZE, PAGE_SIZE + 1, 1 },
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		{ -EINVAL, 1, pfn(0), PAGE_SIZE, 0, 1 },
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		{ -EINVAL, 1, pfn(0), PAGE_SIZE, sgmax + 1, 1 },
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		{ 0, 1, pfn(0), PAGE_SIZE, sgmax, 1 },
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		{ 0, 1, pfn(0), 1, sgmax, 1 },
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		{ 0, 2, pfn(0, 1), 2 * PAGE_SIZE, sgmax, 1 },
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		{ 0, 2, pfn(1, 0), 2 * PAGE_SIZE, sgmax, 2 },
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		{ 0, 3, pfn(0, 1, 2), 3 * PAGE_SIZE, sgmax, 1 },
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		{ 0, 3, pfn(0, 2, 1), 3 * PAGE_SIZE, sgmax, 3 },
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		{ 0, 3, pfn(0, 1, 3), 3 * PAGE_SIZE, sgmax, 2 },
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		{ 0, 3, pfn(1, 2, 4), 3 * PAGE_SIZE, sgmax, 2 },
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		{ 0, 3, pfn(1, 3, 4), 3 * PAGE_SIZE, sgmax, 2 },
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		{ 0, 4, pfn(0, 1, 3, 4), 4 * PAGE_SIZE, sgmax, 2 },
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		{ 0, 5, pfn(0, 1, 3, 4, 5), 5 * PAGE_SIZE, sgmax, 2 },
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		{ 0, 5, pfn(0, 1, 3, 4, 6), 5 * PAGE_SIZE, sgmax, 3 },
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		{ 0, 5, pfn(0, 1, 2, 3, 4), 5 * PAGE_SIZE, sgmax, 1 },
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		{ 0, 5, pfn(0, 1, 2, 3, 4), 5 * PAGE_SIZE, 2 * PAGE_SIZE, 3 },
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		{ 0, 6, pfn(0, 1, 2, 3, 4, 5), 6 * PAGE_SIZE, 2 * PAGE_SIZE, 3 },
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		{ 0, 6, pfn(0, 2, 3, 4, 5, 6), 6 * PAGE_SIZE, 2 * PAGE_SIZE, 4 },
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		{ 0, 6, pfn(0, 1, 3, 4, 5, 6), 6 * PAGE_SIZE, 2 * PAGE_SIZE, 3 },
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		{ 0, 0, NULL, 0, 0, 0 },
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	};
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	unsigned int i;
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	for (i = 0, test = tests; test->expected_segments; test++, i++) {
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		struct page *pages[MAX_PAGES];
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		struct sg_table st;
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		int ret;
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		set_pages(pages, test->pfn, test->num_pages);
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		ret = __sg_alloc_table_from_pages(&st, pages, test->num_pages,
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						  0, test->size, test->max_seg,
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						  GFP_KERNEL);
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		assert(ret == test->alloc_ret);
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		if (test->alloc_ret)
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			continue;
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		assert(st.nents == test->expected_segments);
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		assert(st.orig_nents == test->expected_segments);
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		sg_free_table(&st);
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	}
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	assert(i == (sizeof(tests) / sizeof(tests[0])) - 1);
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	return 0;
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}
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