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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sram-init.c (3700B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * OMAP SRAM detection and management
      4 *
      5 * Copyright (C) 2005 Nokia Corporation
      6 * Written by Tony Lindgren <tony@atomide.com>
      7 */
      8
      9#include <linux/module.h>
     10#include <linux/kernel.h>
     11#include <linux/init.h>
     12#include <linux/io.h>
     13
     14#include <asm/fncpy.h>
     15#include <asm/tlb.h>
     16#include <asm/cacheflush.h>
     17#include <asm/set_memory.h>
     18
     19#include <asm/mach/map.h>
     20
     21#include "soc.h"
     22#include "sram.h"
     23
     24#define OMAP1_SRAM_PA		0x20000000
     25#define SRAM_BOOTLOADER_SZ	0x80
     26#define ROUND_DOWN(value,boundary)	((value) & (~((boundary)-1)))
     27
     28static void __iomem *omap_sram_base;
     29static unsigned long omap_sram_start;
     30static unsigned long omap_sram_skip;
     31static unsigned long omap_sram_size;
     32static void __iomem *omap_sram_ceil;
     33
     34/*
     35 * Memory allocator for SRAM: calculates the new ceiling address
     36 * for pushing a function using the fncpy API.
     37 *
     38 * Note that fncpy requires the returned address to be aligned
     39 * to an 8-byte boundary.
     40 */
     41static void *omap_sram_push_address(unsigned long size)
     42{
     43	unsigned long available, new_ceil = (unsigned long)omap_sram_ceil;
     44
     45	available = omap_sram_ceil - (omap_sram_base + omap_sram_skip);
     46
     47	if (size > available) {
     48		pr_err("Not enough space in SRAM\n");
     49		return NULL;
     50	}
     51
     52	new_ceil -= size;
     53	new_ceil = ROUND_DOWN(new_ceil, FNCPY_ALIGN);
     54	omap_sram_ceil = IOMEM(new_ceil);
     55
     56	return (void __force *)omap_sram_ceil;
     57}
     58
     59void *omap_sram_push(void *funcp, unsigned long size)
     60{
     61	void *sram;
     62	unsigned long base;
     63	int pages;
     64	void *dst = NULL;
     65
     66	sram = omap_sram_push_address(size);
     67	if (!sram)
     68		return NULL;
     69
     70	base = (unsigned long)sram & PAGE_MASK;
     71	pages = PAGE_ALIGN(size) / PAGE_SIZE;
     72
     73	set_memory_rw(base, pages);
     74
     75	dst = fncpy(sram, funcp, size);
     76
     77	set_memory_ro(base, pages);
     78	set_memory_x(base, pages);
     79
     80	return dst;
     81}
     82
     83/*
     84 * The amount of SRAM depends on the core type.
     85 * Note that we cannot try to test for SRAM here because writes
     86 * to secure SRAM will hang the system. Also the SRAM is not
     87 * yet mapped at this point.
     88 * Note that we cannot use ioremap for SRAM, as clock init needs SRAM early.
     89 */
     90static void __init omap_detect_and_map_sram(void)
     91{
     92	unsigned long base;
     93	int pages;
     94
     95	omap_sram_skip = SRAM_BOOTLOADER_SZ;
     96	omap_sram_start = OMAP1_SRAM_PA;
     97
     98	if (cpu_is_omap7xx())
     99		omap_sram_size = 0x32000;	/* 200K */
    100	else if (cpu_is_omap15xx())
    101		omap_sram_size = 0x30000;	/* 192K */
    102	else if (cpu_is_omap1610() || cpu_is_omap1611() ||
    103			cpu_is_omap1621() || cpu_is_omap1710())
    104		omap_sram_size = 0x4000;	/* 16K */
    105	else {
    106		pr_err("Could not detect SRAM size\n");
    107		omap_sram_size = 0x4000;
    108	}
    109
    110	omap_sram_start = ROUND_DOWN(omap_sram_start, PAGE_SIZE);
    111	omap_sram_base = __arm_ioremap_exec(omap_sram_start, omap_sram_size, 1);
    112	if (!omap_sram_base) {
    113		pr_err("SRAM: Could not map\n");
    114		return;
    115	}
    116
    117	omap_sram_ceil = omap_sram_base + omap_sram_size;
    118
    119	/*
    120	 * Looks like we need to preserve some bootloader code at the
    121	 * beginning of SRAM for jumping to flash for reboot to work...
    122	 */
    123	memset_io(omap_sram_base + omap_sram_skip, 0,
    124		  omap_sram_size - omap_sram_skip);
    125
    126	base = (unsigned long)omap_sram_base;
    127	pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE;
    128
    129	set_memory_ro(base, pages);
    130	set_memory_x(base, pages);
    131}
    132
    133static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl);
    134
    135void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl)
    136{
    137	BUG_ON(!_omap_sram_reprogram_clock);
    138	/* On 730, bit 13 must always be 1 */
    139	if (cpu_is_omap7xx())
    140		ckctl |= 0x2000;
    141	_omap_sram_reprogram_clock(dpllctl, ckctl);
    142}
    143
    144int __init omap1_sram_init(void)
    145{
    146	omap_detect_and_map_sram();
    147	_omap_sram_reprogram_clock =
    148			omap_sram_push(omap1_sram_reprogram_clock,
    149					omap1_sram_reprogram_clock_sz);
    150
    151	return 0;
    152}