cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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fpga.c (1629B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * SDK7786 FPGA Support.
      4 *
      5 * Copyright (C) 2010  Paul Mundt
      6 */
      7#include <linux/init.h>
      8#include <linux/io.h>
      9#include <linux/bcd.h>
     10#include <mach/fpga.h>
     11#include <linux/sizes.h>
     12
     13#define FPGA_REGS_OFFSET	0x03fff800
     14#define FPGA_REGS_SIZE		0x490
     15
     16/*
     17 * The FPGA can be mapped in any of the generally available areas,
     18 * so we attempt to scan for it using the fixed SRSTR read magic.
     19 *
     20 * Once the FPGA is located, the rest of the mapping data for the other
     21 * components can be determined dynamically from its section mapping
     22 * registers.
     23 */
     24static void __iomem *sdk7786_fpga_probe(void)
     25{
     26	unsigned long area;
     27	void __iomem *base;
     28
     29	/*
     30	 * Iterate over all of the areas where the FPGA could be mapped.
     31	 * The possible range is anywhere from area 0 through 6, area 7
     32	 * is reserved.
     33	 */
     34	for (area = PA_AREA0; area < PA_AREA7; area += SZ_64M) {
     35		base = ioremap(area + FPGA_REGS_OFFSET, FPGA_REGS_SIZE);
     36		if (!base) {
     37			/* Failed to remap this area, move along. */
     38			continue;
     39		}
     40
     41		if (ioread16(base + SRSTR) == SRSTR_MAGIC)
     42			return base;	/* Found it! */
     43
     44		iounmap(base);
     45	}
     46
     47	return NULL;
     48}
     49
     50void __iomem *sdk7786_fpga_base;
     51
     52void __init sdk7786_fpga_init(void)
     53{
     54	u16 version, date;
     55
     56	sdk7786_fpga_base = sdk7786_fpga_probe();
     57	if (unlikely(!sdk7786_fpga_base)) {
     58		panic("FPGA detection failed.\n");
     59		return;
     60	}
     61
     62	version = fpga_read_reg(FPGAVR);
     63	date = fpga_read_reg(FPGADR);
     64
     65	pr_info("\tFPGA version:\t%d.%d (built on %d/%d/%d)\n",
     66		bcd2bin(version >> 8) & 0xf, bcd2bin(version & 0xf),
     67		((date >> 12) & 0xf) + 2000,
     68		(date >> 8) & 0xf, bcd2bin(date & 0xff));
     69}