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27 lines
492 B
27 lines
492 B
#include <linux/kernel.h> |
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#include <asm/div64.h> |
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#include <linux/reciprocal_div.h> |
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#include <linux/export.h> |
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/* |
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* For a description of the algorithm please have a look at |
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* include/linux/reciprocal_div.h |
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*/ |
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struct reciprocal_value reciprocal_value(u32 d) |
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{ |
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struct reciprocal_value R; |
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u64 m; |
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int l; |
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l = fls(d - 1); |
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m = ((1ULL << 32) * ((1ULL << l) - d)); |
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do_div(m, d); |
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++m; |
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R.m = (u32)m; |
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R.sh1 = min(l, 1); |
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R.sh2 = max(l - 1, 0); |
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return R; |
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} |
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EXPORT_SYMBOL(reciprocal_value);
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