1 /*
2 * Copyright 2015 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 */
23 #include <asm/div64.h>
24
25 #define SHIFT_AMOUNT 16 /* We multiply all original integers with 2^SHIFT_AMOUNT to get the fInt representation */
26
27 #define PRECISION 5 /* Change this value to change the number of decimal places in the final output - 5 is a good default */
28
29 #define SHIFTED_2 (2 << SHIFT_AMOUNT)
30 #define MAX (1 << (SHIFT_AMOUNT - 1)) - 1 /* 32767 - Might change in the future */
31
32 /* -------------------------------------------------------------------------------
33 * NEW TYPE - fINT
34 * -------------------------------------------------------------------------------
35 * A variable of type fInt can be accessed in 3 ways using the dot (.) operator
36 * fInt A;
37 * A.full => The full number as it is. Generally not easy to read
38 * A.partial.real => Only the integer portion
39 * A.partial.decimal => Only the fractional portion
40 */
41 typedef union _fInt {
42 int full;
43 struct _partial {
44 unsigned int decimal: SHIFT_AMOUNT; /*Needs to always be unsigned*/
45 int real: 32 - SHIFT_AMOUNT;
46 } partial;
47 } fInt;
48
49 /* -------------------------------------------------------------------------------
50 * Function Declarations
51 * -------------------------------------------------------------------------------
52 */
53 static fInt ConvertToFraction(int); /* Use this to convert an INT to a FINT */
54 static fInt Convert_ULONG_ToFraction(uint32_t); /* Use this to convert an uint32_t to a FINT */
55 static fInt GetScaledFraction(int, int); /* Use this to convert an INT to a FINT after scaling it by a factor */
56 static int ConvertBackToInteger(fInt); /* Convert a FINT back to an INT that is scaled by 1000 (i.e. last 3 digits are the decimal digits) */
57
58 static fInt fNegate(fInt); /* Returns -1 * input fInt value */
59 static fInt fAdd (fInt, fInt); /* Returns the sum of two fInt numbers */
60 static fInt fSubtract (fInt A, fInt B); /* Returns A-B - Sometimes easier than Adding negative numbers */
61 static fInt fMultiply (fInt, fInt); /* Returns the product of two fInt numbers */
62 static fInt fDivide (fInt A, fInt B); /* Returns A/B */
63 static fInt fGetSquare(fInt); /* Returns the square of a fInt number */
64 static fInt fSqrt(fInt); /* Returns the Square Root of a fInt number */
65
66 static int uAbs(int); /* Returns the Absolute value of the Int */
67 static int uPow(int base, int exponent); /* Returns base^exponent an INT */
68
69 static void SolveQuadracticEqn(fInt, fInt, fInt, fInt[]); /* Returns the 2 roots via the array */
70 static bool Equal(fInt, fInt); /* Returns true if two fInts are equal to each other */
71 static bool GreaterThan(fInt A, fInt B); /* Returns true if A > B */
72
73 static fInt fExponential(fInt exponent); /* Can be used to calculate e^exponent */
74 static fInt fNaturalLog(fInt value); /* Can be used to calculate ln(value) */
75
76 /* Fuse decoding functions
77 * -------------------------------------------------------------------------------------
78 */
79 static fInt fDecodeLinearFuse(uint32_t fuse_value, fInt f_min, fInt f_range, uint32_t bitlength);
80 static fInt fDecodeLogisticFuse(uint32_t fuse_value, fInt f_average, fInt f_range, uint32_t bitlength);
81 static fInt fDecodeLeakageID (uint32_t leakageID_fuse, fInt ln_max_div_min, fInt f_min, uint32_t bitlength);
82
83 /* Internal Support Functions - Use these ONLY for testing or adding to internal functions
84 * -------------------------------------------------------------------------------------
85 * Some of the following functions take two INTs as their input - This is unsafe for a variety of reasons.
86 */
87 static fInt Divide (int, int); /* Divide two INTs and return result as FINT */
88 static fInt fNegate(fInt);
89
90 static int uGetScaledDecimal (fInt); /* Internal function */
91 static int GetReal (fInt A); /* Internal function */
92
93 /* -------------------------------------------------------------------------------------
94 * TROUBLESHOOTING INFORMATION
95 * -------------------------------------------------------------------------------------
96 * 1) ConvertToFraction - InputOutOfRangeException: Only accepts numbers smaller than MAX (default: 32767)
97 * 2) fAdd - OutputOutOfRangeException: Output bigger than MAX (default: 32767)
98 * 3) fMultiply - OutputOutOfRangeException:
99 * 4) fGetSquare - OutputOutOfRangeException:
100 * 5) fDivide - DivideByZeroException
101 * 6) fSqrt - NegativeSquareRootException: Input cannot be a negative number
102 */
103
104 /* -------------------------------------------------------------------------------------
105 * START OF CODE
106 * -------------------------------------------------------------------------------------
107 */
fExponential(fInt exponent)108 static fInt fExponential(fInt exponent) /*Can be used to calculate e^exponent*/
109 {
110 uint32_t i;
111 bool bNegated = false;
112
113 fInt fPositiveOne = ConvertToFraction(1);
114 fInt fZERO = ConvertToFraction(0);
115
116 fInt lower_bound = Divide(78, 10000);
117 fInt solution = fPositiveOne; /*Starting off with baseline of 1 */
118 fInt error_term;
119
120 static const uint32_t k_array[11] = {55452, 27726, 13863, 6931, 4055, 2231, 1178, 606, 308, 155, 78};
121 static const uint32_t expk_array[11] = {2560000, 160000, 40000, 20000, 15000, 12500, 11250, 10625, 10313, 10156, 10078};
122
123 if (GreaterThan(fZERO, exponent)) {
124 exponent = fNegate(exponent);
125 bNegated = true;
126 }
127
128 while (GreaterThan(exponent, lower_bound)) {
129 for (i = 0; i < 11; i++) {
130 if (GreaterThan(exponent, GetScaledFraction(k_array[i], 10000))) {
131 exponent = fSubtract(exponent, GetScaledFraction(k_array[i], 10000));
132 solution = fMultiply(solution, GetScaledFraction(expk_array[i], 10000));
133 }
134 }
135 }
136
137 error_term = fAdd(fPositiveOne, exponent);
138
139 solution = fMultiply(solution, error_term);
140
141 if (bNegated)
142 solution = fDivide(fPositiveOne, solution);
143
144 return solution;
145 }
146
fNaturalLog(fInt value)147 static fInt fNaturalLog(fInt value)
148 {
149 uint32_t i;
150 fInt upper_bound = Divide(8, 1000);
151 fInt fNegativeOne = ConvertToFraction(-1);
152 fInt solution = ConvertToFraction(0); /*Starting off with baseline of 0 */
153 fInt error_term;
154
155 static const uint32_t k_array[10] = {160000, 40000, 20000, 15000, 12500, 11250, 10625, 10313, 10156, 10078};
156 static const uint32_t logk_array[10] = {27726, 13863, 6931, 4055, 2231, 1178, 606, 308, 155, 78};
157
158 while (GreaterThan(fAdd(value, fNegativeOne), upper_bound)) {
159 for (i = 0; i < 10; i++) {
160 if (GreaterThan(value, GetScaledFraction(k_array[i], 10000))) {
161 value = fDivide(value, GetScaledFraction(k_array[i], 10000));
162 solution = fAdd(solution, GetScaledFraction(logk_array[i], 10000));
163 }
164 }
165 }
166
167 error_term = fAdd(fNegativeOne, value);
168
169 return fAdd(solution, error_term);
170 }
171
fDecodeLinearFuse(uint32_t fuse_value,fInt f_min,fInt f_range,uint32_t bitlength)172 static fInt fDecodeLinearFuse(uint32_t fuse_value, fInt f_min, fInt f_range, uint32_t bitlength)
173 {
174 fInt f_fuse_value = Convert_ULONG_ToFraction(fuse_value);
175 fInt f_bit_max_value = Convert_ULONG_ToFraction((uPow(2, bitlength)) - 1);
176
177 fInt f_decoded_value;
178
179 f_decoded_value = fDivide(f_fuse_value, f_bit_max_value);
180 f_decoded_value = fMultiply(f_decoded_value, f_range);
181 f_decoded_value = fAdd(f_decoded_value, f_min);
182
183 return f_decoded_value;
184 }
185
186
fDecodeLogisticFuse(uint32_t fuse_value,fInt f_average,fInt f_range,uint32_t bitlength)187 static fInt fDecodeLogisticFuse(uint32_t fuse_value, fInt f_average, fInt f_range, uint32_t bitlength)
188 {
189 fInt f_fuse_value = Convert_ULONG_ToFraction(fuse_value);
190 fInt f_bit_max_value = Convert_ULONG_ToFraction((uPow(2, bitlength)) - 1);
191
192 fInt f_CONSTANT_NEG13 = ConvertToFraction(-13);
193 fInt f_CONSTANT1 = ConvertToFraction(1);
194
195 fInt f_decoded_value;
196
197 f_decoded_value = fSubtract(fDivide(f_bit_max_value, f_fuse_value), f_CONSTANT1);
198 f_decoded_value = fNaturalLog(f_decoded_value);
199 f_decoded_value = fMultiply(f_decoded_value, fDivide(f_range, f_CONSTANT_NEG13));
200 f_decoded_value = fAdd(f_decoded_value, f_average);
201
202 return f_decoded_value;
203 }
204
fDecodeLeakageID(uint32_t leakageID_fuse,fInt ln_max_div_min,fInt f_min,uint32_t bitlength)205 static fInt fDecodeLeakageID (uint32_t leakageID_fuse, fInt ln_max_div_min, fInt f_min, uint32_t bitlength)
206 {
207 fInt fLeakage;
208 fInt f_bit_max_value = Convert_ULONG_ToFraction((uPow(2, bitlength)) - 1);
209
210 fLeakage = fMultiply(ln_max_div_min, Convert_ULONG_ToFraction(leakageID_fuse));
211 fLeakage = fDivide(fLeakage, f_bit_max_value);
212 fLeakage = fExponential(fLeakage);
213 fLeakage = fMultiply(fLeakage, f_min);
214
215 return fLeakage;
216 }
217
ConvertToFraction(int X)218 static fInt ConvertToFraction(int X) /*Add all range checking here. Is it possible to make fInt a private declaration? */
219 {
220 fInt temp;
221
222 if (X <= MAX)
223 temp.full = (X << SHIFT_AMOUNT);
224 else
225 temp.full = 0;
226
227 return temp;
228 }
229
fNegate(fInt X)230 static fInt fNegate(fInt X)
231 {
232 fInt CONSTANT_NEGONE = ConvertToFraction(-1);
233 return fMultiply(X, CONSTANT_NEGONE);
234 }
235
Convert_ULONG_ToFraction(uint32_t X)236 static fInt Convert_ULONG_ToFraction(uint32_t X)
237 {
238 fInt temp;
239
240 if (X <= MAX)
241 temp.full = (X << SHIFT_AMOUNT);
242 else
243 temp.full = 0;
244
245 return temp;
246 }
247
GetScaledFraction(int X,int factor)248 static fInt GetScaledFraction(int X, int factor)
249 {
250 int times_shifted, factor_shifted;
251 bool bNEGATED;
252 fInt fValue;
253
254 times_shifted = 0;
255 factor_shifted = 0;
256 bNEGATED = false;
257
258 if (X < 0) {
259 X = -1*X;
260 bNEGATED = true;
261 }
262
263 if (factor < 0) {
264 factor = -1*factor;
265 bNEGATED = !bNEGATED; /*If bNEGATED = true due to X < 0, this will cover the case of negative cancelling negative */
266 }
267
268 if ((X > MAX) || factor > MAX) {
269 if ((X/factor) <= MAX) {
270 while (X > MAX) {
271 X = X >> 1;
272 times_shifted++;
273 }
274
275 while (factor > MAX) {
276 factor = factor >> 1;
277 factor_shifted++;
278 }
279 } else {
280 fValue.full = 0;
281 return fValue;
282 }
283 }
284
285 if (factor == 1)
286 return ConvertToFraction(X);
287
288 fValue = fDivide(ConvertToFraction(X * uPow(-1, bNEGATED)), ConvertToFraction(factor));
289
290 fValue.full = fValue.full << times_shifted;
291 fValue.full = fValue.full >> factor_shifted;
292
293 return fValue;
294 }
295
296 /* Addition using two fInts */
fAdd(fInt X,fInt Y)297 static fInt fAdd (fInt X, fInt Y)
298 {
299 fInt Sum;
300
301 Sum.full = X.full + Y.full;
302
303 return Sum;
304 }
305
306 /* Addition using two fInts */
fSubtract(fInt X,fInt Y)307 static fInt fSubtract (fInt X, fInt Y)
308 {
309 fInt Difference;
310
311 Difference.full = X.full - Y.full;
312
313 return Difference;
314 }
315
Equal(fInt A,fInt B)316 static bool Equal(fInt A, fInt B)
317 {
318 if (A.full == B.full)
319 return true;
320 else
321 return false;
322 }
323
GreaterThan(fInt A,fInt B)324 static bool GreaterThan(fInt A, fInt B)
325 {
326 if (A.full > B.full)
327 return true;
328 else
329 return false;
330 }
331
fMultiply(fInt X,fInt Y)332 static fInt fMultiply (fInt X, fInt Y) /* Uses 64-bit integers (int64_t) */
333 {
334 fInt Product;
335 int64_t tempProduct;
336
337 /*The following is for a very specific common case: Non-zero number with ONLY fractional portion*/
338 /* TEMPORARILY DISABLED - CAN BE USED TO IMPROVE PRECISION
339 bool X_LessThanOne, Y_LessThanOne;
340
341 X_LessThanOne = (X.partial.real == 0 && X.partial.decimal != 0 && X.full >= 0);
342 Y_LessThanOne = (Y.partial.real == 0 && Y.partial.decimal != 0 && Y.full >= 0);
343
344 if (X_LessThanOne && Y_LessThanOne) {
345 Product.full = X.full * Y.full;
346 return Product
347 }*/
348
349 tempProduct = ((int64_t)X.full) * ((int64_t)Y.full); /*Q(16,16)*Q(16,16) = Q(32, 32) - Might become a negative number! */
350 tempProduct = tempProduct >> 16; /*Remove lagging 16 bits - Will lose some precision from decimal; */
351 Product.full = (int)tempProduct; /*The int64_t will lose the leading 16 bits that were part of the integer portion */
352
353 return Product;
354 }
355
fDivide(fInt X,fInt Y)356 static fInt fDivide (fInt X, fInt Y)
357 {
358 fInt fZERO, fQuotient;
359 int64_t longlongX, longlongY;
360
361 fZERO = ConvertToFraction(0);
362
363 if (Equal(Y, fZERO))
364 return fZERO;
365
366 longlongX = (int64_t)X.full;
367 longlongY = (int64_t)Y.full;
368
369 longlongX = longlongX << 16; /*Q(16,16) -> Q(32,32) */
370
371 div64_s64(longlongX, longlongY); /*Q(32,32) divided by Q(16,16) = Q(16,16) Back to original format */
372
373 fQuotient.full = (int)longlongX;
374 return fQuotient;
375 }
376
ConvertBackToInteger(fInt A)377 static int ConvertBackToInteger (fInt A) /*THIS is the function that will be used to check with the Golden settings table*/
378 {
379 fInt fullNumber, scaledDecimal, scaledReal;
380
381 scaledReal.full = GetReal(A) * uPow(10, PRECISION-1); /* DOUBLE CHECK THISSSS!!! */
382
383 scaledDecimal.full = uGetScaledDecimal(A);
384
385 fullNumber = fAdd(scaledDecimal, scaledReal);
386
387 return fullNumber.full;
388 }
389
fGetSquare(fInt A)390 static fInt fGetSquare(fInt A)
391 {
392 return fMultiply(A, A);
393 }
394
395 /* x_new = x_old - (x_old^2 - C) / (2 * x_old) */
fSqrt(fInt num)396 static fInt fSqrt(fInt num)
397 {
398 fInt F_divide_Fprime, Fprime;
399 fInt test;
400 fInt twoShifted;
401 int seed, counter, error;
402 fInt x_new, x_old, C, y;
403
404 fInt fZERO = ConvertToFraction(0);
405
406 /* (0 > num) is the same as (num < 0), i.e., num is negative */
407
408 if (GreaterThan(fZERO, num) || Equal(fZERO, num))
409 return fZERO;
410
411 C = num;
412
413 if (num.partial.real > 3000)
414 seed = 60;
415 else if (num.partial.real > 1000)
416 seed = 30;
417 else if (num.partial.real > 100)
418 seed = 10;
419 else
420 seed = 2;
421
422 counter = 0;
423
424 if (Equal(num, fZERO)) /*Square Root of Zero is zero */
425 return fZERO;
426
427 twoShifted = ConvertToFraction(2);
428 x_new = ConvertToFraction(seed);
429
430 do {
431 counter++;
432
433 x_old.full = x_new.full;
434
435 test = fGetSquare(x_old); /*1.75*1.75 is reverting back to 1 when shifted down */
436 y = fSubtract(test, C); /*y = f(x) = x^2 - C; */
437
438 Fprime = fMultiply(twoShifted, x_old);
439 F_divide_Fprime = fDivide(y, Fprime);
440
441 x_new = fSubtract(x_old, F_divide_Fprime);
442
443 error = ConvertBackToInteger(x_new) - ConvertBackToInteger(x_old);
444
445 if (counter > 20) /*20 is already way too many iterations. If we dont have an answer by then, we never will*/
446 return x_new;
447
448 } while (uAbs(error) > 0);
449
450 return x_new;
451 }
452
SolveQuadracticEqn(fInt A,fInt B,fInt C,fInt Roots[])453 static void SolveQuadracticEqn(fInt A, fInt B, fInt C, fInt Roots[])
454 {
455 fInt *pRoots = &Roots[0];
456 fInt temp, root_first, root_second;
457 fInt f_CONSTANT10, f_CONSTANT100;
458
459 f_CONSTANT100 = ConvertToFraction(100);
460 f_CONSTANT10 = ConvertToFraction(10);
461
462 while (GreaterThan(A, f_CONSTANT100) || GreaterThan(B, f_CONSTANT100) || GreaterThan(C, f_CONSTANT100)) {
463 A = fDivide(A, f_CONSTANT10);
464 B = fDivide(B, f_CONSTANT10);
465 C = fDivide(C, f_CONSTANT10);
466 }
467
468 temp = fMultiply(ConvertToFraction(4), A); /* root = 4*A */
469 temp = fMultiply(temp, C); /* root = 4*A*C */
470 temp = fSubtract(fGetSquare(B), temp); /* root = b^2 - 4AC */
471 temp = fSqrt(temp); /*root = Sqrt (b^2 - 4AC); */
472
473 root_first = fSubtract(fNegate(B), temp); /* b - Sqrt(b^2 - 4AC) */
474 root_second = fAdd(fNegate(B), temp); /* b + Sqrt(b^2 - 4AC) */
475
476 root_first = fDivide(root_first, ConvertToFraction(2)); /* [b +- Sqrt(b^2 - 4AC)]/[2] */
477 root_first = fDivide(root_first, A); /*[b +- Sqrt(b^2 - 4AC)]/[2*A] */
478
479 root_second = fDivide(root_second, ConvertToFraction(2)); /* [b +- Sqrt(b^2 - 4AC)]/[2] */
480 root_second = fDivide(root_second, A); /*[b +- Sqrt(b^2 - 4AC)]/[2*A] */
481
482 *(pRoots + 0) = root_first;
483 *(pRoots + 1) = root_second;
484 }
485
486 /* -----------------------------------------------------------------------------
487 * SUPPORT FUNCTIONS
488 * -----------------------------------------------------------------------------
489 */
490
491 /* Conversion Functions */
GetReal(fInt A)492 static int GetReal (fInt A)
493 {
494 return (A.full >> SHIFT_AMOUNT);
495 }
496
Divide(int X,int Y)497 static fInt Divide (int X, int Y)
498 {
499 fInt A, B, Quotient;
500
501 A.full = X << SHIFT_AMOUNT;
502 B.full = Y << SHIFT_AMOUNT;
503
504 Quotient = fDivide(A, B);
505
506 return Quotient;
507 }
508
uGetScaledDecimal(fInt A)509 static int uGetScaledDecimal (fInt A) /*Converts the fractional portion to whole integers - Costly function */
510 {
511 int dec[PRECISION];
512 int i, scaledDecimal = 0, tmp = A.partial.decimal;
513
514 for (i = 0; i < PRECISION; i++) {
515 dec[i] = tmp / (1 << SHIFT_AMOUNT);
516 tmp = tmp - ((1 << SHIFT_AMOUNT)*dec[i]);
517 tmp *= 10;
518 scaledDecimal = scaledDecimal + dec[i]*uPow(10, PRECISION - 1 - i);
519 }
520
521 return scaledDecimal;
522 }
523
uPow(int base,int power)524 static int uPow(int base, int power)
525 {
526 if (power == 0)
527 return 1;
528 else
529 return (base)*uPow(base, power - 1);
530 }
531
uAbs(int X)532 static int uAbs(int X)
533 {
534 if (X < 0)
535 return (X * -1);
536 else
537 return X;
538 }
539
fRoundUpByStepSize(fInt A,fInt fStepSize,bool error_term)540 static fInt fRoundUpByStepSize(fInt A, fInt fStepSize, bool error_term)
541 {
542 fInt solution;
543
544 solution = fDivide(A, fStepSize);
545 solution.partial.decimal = 0; /*All fractional digits changes to 0 */
546
547 if (error_term)
548 solution.partial.real += 1; /*Error term of 1 added */
549
550 solution = fMultiply(solution, fStepSize);
551 solution = fAdd(solution, fStepSize);
552
553 return solution;
554 }
555
556