29 lines
528 B
C
29 lines
528 B
C
// SPDX-License-Identifier: GPL-2.0
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#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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