cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

pllgt215.c (2507B)

      1/*
      2 * Copyright 2010 Red Hat 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 * Authors: Ben Skeggs
     23 */
     24#include "pll.h"
     25
     26#include <subdev/bios.h>
     27#include <subdev/bios/pll.h>
     28
     29int
     30gt215_pll_calc(struct nvkm_subdev *subdev, struct nvbios_pll *info,
     31	       u32 freq, int *pN, int *pfN, int *pM, int *P)
     32{
     33	u32 best_err = ~0, err;
     34	int M, lM, hM, N, fN;
     35
     36	*P = info->vco1.max_freq / freq;
     37	if (*P > info->max_p)
     38		*P = info->max_p;
     39	if (*P < info->min_p)
     40		*P = info->min_p;
     41
     42	lM = (info->refclk + info->vco1.max_inputfreq) / info->vco1.max_inputfreq;
     43	lM = max(lM, (int)info->vco1.min_m);
     44	hM = (info->refclk + info->vco1.min_inputfreq) / info->vco1.min_inputfreq;
     45	hM = min(hM, (int)info->vco1.max_m);
     46	lM = min(lM, hM);
     47
     48	for (M = lM; M <= hM; M++) {
     49		u32 tmp = freq * *P * M;
     50		N  = tmp / info->refclk;
     51		fN = tmp % info->refclk;
     52
     53		if (!pfN) {
     54			if (fN >= info->refclk / 2)
     55				N++;
     56		} else {
     57			if (fN <  info->refclk / 2)
     58				N--;
     59			fN = tmp - (N * info->refclk);
     60		}
     61
     62		if (N < info->vco1.min_n)
     63			continue;
     64		if (N > info->vco1.max_n)
     65			break;
     66
     67		err = abs(freq - (info->refclk * N / M / *P));
     68		if (err < best_err) {
     69			best_err = err;
     70			*pN = N;
     71			*pM = M;
     72		}
     73
     74		if (pfN) {
     75			*pfN = ((fN << 13) + info->refclk / 2) / info->refclk;
     76			*pfN = (*pfN - 4096) & 0xffff;
     77			return freq;
     78		}
     79	}
     80
     81	if (unlikely(best_err == ~0)) {
     82		nvkm_error(subdev, "unable to find matching pll values\n");
     83		return -EINVAL;
     84	}
     85
     86	return info->refclk * *pN / *pM / *P;
     87}