path: root/arch/parisc/mm/init.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/arch/parisc/mm/init.c
 *
 *  Copyright (C) 1995	Linus Torvalds
 *  Copyright 1999 SuSE GmbH
 *    changed by Philipp Rumpf
 *  Copyright 1999 Philipp Rumpf (prumpf@tux.org)
 *  Copyright 2004 Randolph Chung (tausq@debian.org)
 *  Copyright 2006-2007 Helge Deller (deller@gmx.de)
 *
 */


#include <linux/module.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/gfp.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/swap.h>
#include <linux/unistd.h>
#include <linux/nodemask.h>	/* for node_online_map */
#include <linux/pagemap.h>	/* for release_pages */
#include <linux/compat.h>
#include <linux/execmem.h>

#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/pdc_chassis.h>
#include <asm/mmzone.h>
#include <asm/sections.h>
#include <asm/msgbuf.h>
#include <asm/sparsemem.h>
#include <asm/asm-offsets.h>
#include <asm/shmbuf.h>

extern int  data_start;
extern void parisc_kernel_start(void);	/* Kernel entry point in head.S */

#if CONFIG_PGTABLE_LEVELS == 3
pmd_t pmd0[PTRS_PER_PMD] __section(".data..vm0.pmd") __attribute__ ((aligned(PAGE_SIZE)));
#endif

pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".data..vm0.pgd") __attribute__ ((aligned(PAGE_SIZE)));
pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __section(".data..vm0.pte") __attribute__ ((aligned(PAGE_SIZE)));

static struct resource data_resource = {
	.name	= "Kernel data",
	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
};

static struct resource code_resource = {
	.name	= "Kernel code",
	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
};

static struct resource pdcdata_resource = {
	.name	= "PDC data (Page Zero)",
	.start	= 0,
	.end	= 0x9ff,
	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
};

static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __ro_after_init;

/* The following array is initialized from the firmware specific
 * information retrieved in kernel/inventory.c.
 */

physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata;
int npmem_ranges __initdata;

#ifdef CONFIG_64BIT
#define MAX_MEM         (1UL << MAX_PHYSMEM_BITS)
#else /* !CONFIG_64BIT */
#define MAX_MEM         (3584U*1024U*1024U)
#endif /* !CONFIG_64BIT */

static unsigned long mem_limit __read_mostly = MAX_MEM;

static void __init mem_limit_func(void)
{
	char *cp, *end;
	unsigned long limit;

	/* We need this before __setup() functions are called */

	limit = MAX_MEM;
	for (cp = boot_command_line; *cp; ) {
		if (memcmp(cp, "mem=", 4) == 0) {
			cp += 4;
			limit = memparse(cp, &end);
			if (end != cp)
				break;
			cp = end;
		} else {
			while (*cp != ' ' && *cp)
				++cp;
			while (*cp == ' ')
				++cp;
		}
	}

	if (limit < mem_limit)
		mem_limit = limit;
}

#define MAX_GAP (0x40000000UL >> PAGE_SHIFT)

static void __init setup_bootmem(void)
{
	unsigned long mem_max;
#ifndef CONFIG_SPARSEMEM
	physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1];
	int npmem_holes;
#endif
	int i, sysram_resource_count;

	disable_sr_hashing(); /* Turn off space register hashing */

	/*
	 * Sort the ranges. Since the number of ranges is typically
	 * small, and performance is not an issue here, just do
	 * a simple insertion sort.
	 */

	for (i = 1; i < npmem_ranges; i++) {
		int j;

		for (j = i; j > 0; j--) {
			if (pmem_ranges[j-1].start_pfn <
			    pmem_ranges[j].start_pfn) {

				break;
			}
			swap(pmem_ranges[j-1], pmem_ranges[j]);
		}
	}

#ifndef CONFIG_SPARSEMEM
	/*
	 * Throw out ranges that are too far apart (controlled by
	 * MAX_GAP).
	 */

	for (i = 1; i < npmem_ranges; i++) {
		if (pmem_ranges[i].start_pfn -
			(pmem_ranges[i-1].start_pfn +
			 pmem_ranges[i-1].pages) > MAX_GAP) {
			npmem_ranges = i;
			printk("Large gap in memory detected (%ld pages). "
			       "Consider turning on CONFIG_SPARSEMEM\n",
			       pmem_ranges[i].start_pfn -
			       (pmem_ranges[i-1].start_pfn +
			        pmem_ranges[i-1].pages));
			break;
		}
	}
#endif

	/* Print the memory ranges */
	pr_info("Memory Ranges:\n");

	for (i = 0; i < npmem_ranges; i++) {
		struct resource *res = &sysram_resources[i];
		unsigned long start;
		unsigned long size;

		size = (pmem_ranges[i].pages << PAGE_SHIFT);
		start = (pmem_ranges[i].start_pfn << PAGE_SHIFT);
		pr_info("%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n",
			i, start, start + (size - 1), size >> 20);

		/* request memory resource */
		res->name = "System RAM";
		res->start = start;
		res->end = start + size - 1;
		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
		request_resource(&iomem_resource, res);
	}

	sysram_resource_count = npmem_ranges;

	/*
	 * For 32 bit kernels we limit the amount of memory we can
	 * support, in order to preserve enough kernel address space
	 * for other purposes. For 64 bit kernels we don't normally
	 * limit the memory, but this mechanism can be used to
	 * artificially limit the amount of memory (and it is written
	 * to work with multiple memory ranges).
	 */

	mem_limit_func();       /* check for "mem=" argument */

	mem_max = 0;
	for (i = 0; i < npmem_ranges; i++) {
		unsigned long rsize;

		rsize = pmem_ranges