linux_dsm_epyc7002/arch/powerpc/mm/nohash/40x.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

155 lines
4.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* This file contains the routines for initializing the MMU
* on the 4xx series of chips.
* -- paulus
*
* Derived from arch/ppc/mm/init.c:
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
* and Cort Dougan (PReP) (cort@cs.nmt.edu)
* Copyright (C) 1996 Paul Mackerras
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*/
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/stddef.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/highmem.h>
#include <linux/memblock.h>
#include <asm/pgalloc.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <linux/uaccess.h>
#include <asm/smp.h>
#include <asm/bootx.h>
#include <asm/machdep.h>
#include <asm/setup.h>
#include <mm/mmu_decl.h>
extern int __map_without_ltlbs;
/*
* MMU_init_hw does the chip-specific initialization of the MMU hardware.
*/
void __init MMU_init_hw(void)
{
/*
* The Zone Protection Register (ZPR) defines how protection will
* be applied to every page which is a member of a given zone. At
* present, we utilize only two of the 4xx's zones.
* The zone index bits (of ZSEL) in the PTE are used for software
* indicators, except the LSB. For user access, zone 1 is used,
* for kernel access, zone 0 is used. We set all but zone 1
* to zero, allowing only kernel access as indicated in the PTE.
* For zone 1, we set a 01 binary (a value of 10 will not work)
* to allow user access as indicated in the PTE. This also allows
* kernel access as indicated in the PTE.
*/
mtspr(SPRN_ZPR, 0x10000000);
flush_instruction_cache();
/*
* Set up the real-mode cache parameters for the exception vector
* handlers (which are run in real-mode).
*/
mtspr(SPRN_DCWR, 0x00000000); /* All caching is write-back */
/*
* Cache instruction and data space where the exception
* vectors and the kernel live in real-mode.
*/
mtspr(SPRN_DCCR, 0xFFFF0000); /* 2GByte of data space at 0x0. */
mtspr(SPRN_ICCR, 0xFFFF0000); /* 2GByte of instr. space at 0x0. */
}
#define LARGE_PAGE_SIZE_16M (1<<24)
#define LARGE_PAGE_SIZE_4M (1<<22)
unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
{
unsigned long v, s, mapped;
phys_addr_t p;
v = KERNELBASE;
p = 0;
s = total_lowmem;
if (__map_without_ltlbs)
return 0;
while (s >= LARGE_PAGE_SIZE_16M) {
pmd_t *pmdp;
unsigned long val = p | _PMD_SIZE_16M | _PAGE_EXEC | _PAGE_HWWRITE;
pmdp = pmd_offset(pud_offset(pgd_offset_k(v), v), v);
*pmdp++ = __pmd(val);
*pmdp++ = __pmd(val);
*pmdp++ = __pmd(val);
*pmdp++ = __pmd(val);
v += LARGE_PAGE_SIZE_16M;
p += LARGE_PAGE_SIZE_16M;
s -= LARGE_PAGE_SIZE_16M;
}
while (s >= LARGE_PAGE_SIZE_4M) {
pmd_t *pmdp;
unsigned long val = p | _PMD_SIZE_4M | _PAGE_EXEC | _PAGE_HWWRITE;
pmdp = pmd_offset(pud_offset(pgd_offset_k(v), v), v);
*pmdp = __pmd(val);
v += LARGE_PAGE_SIZE_4M;
p += LARGE_PAGE_SIZE_4M;
s -= LARGE_PAGE_SIZE_4M;
}
mapped = total_lowmem - s;
/* If the size of RAM is not an exact power of two, we may not
* have covered RAM in its entirety with 16 and 4 MiB
* pages. Consequently, restrict the top end of RAM currently
* allocable so that calls to the MEMBLOCK to allocate PTEs for "tail"
* coverage with normal-sized pages (or other reasons) do not
* attempt to allocate outside the allowed range.
*/
memblock_set_current_limit(mapped);
return mapped;
}
void setup_initial_memory_limit(phys_addr_t first_memblock_base,
phys_addr_t first_memblock_size)
{
/* We don't currently support the first MEMBLOCK not mapping 0
* physical on those processors
*/
BUG_ON(first_memblock_base != 0);
/* 40x can only access 16MB at the moment (see head_40x.S) */
memblock_set_current_limit(min_t(u64, first_memblock_size, 0x00800000));
}