path: root/arch/powerpc/mm/mem.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  PowerPC version
 *    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
 *  PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 */

#include <linux/export.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/gfp.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/highmem.h>
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <linux/suspend.h>
#include <linux/hugetlb.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/memremap.h>
#include <linux/dma-direct.h>
#include <linux/kprobes.h>

#include <asm/prom.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/mmu.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/btext.h>
#include <asm/tlb.h>
#include <asm/sections.h>
#include <asm/sparsemem.h>
#include <asm/vdso.h>
#include <asm/fixmap.h>
#include <asm/swiotlb.h>
#include <asm/rtas.h>
#include <asm/kasan.h>

#include <mm/mmu_decl.h>

#ifndef CPU_FTR_COHERENT_ICACHE
#define CPU_FTR_COHERENT_ICACHE	0	/* XXX for now */
#define CPU_FTR_NOEXECUTE	0
#endif

unsigned long long memory_limit;
bool init_mem_is_free;

#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
EXPORT_SYMBOL(kmap_pte);
#endif

pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
			      unsigned long size, pgprot_t vma_prot)
{
	if (ppc_md.phys_mem_access_prot)
		return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);

	if (!page_is_ram(pfn))
		vma_prot = pgprot_noncached(vma_prot);

	return vma_prot;
}
EXPORT_SYMBOL(phys_mem_access_prot);

#ifdef CONFIG_MEMORY_HOTPLUG

#ifdef CONFIG_NUMA
int memory_add_physaddr_to_nid(u64 start)
{
	return hot_add_scn_to_nid(start);
}
#endif

int __weak create_section_mapping(unsigned long start, unsigned long end,
				  int nid, pgprot_t prot)
{
	return -ENODEV;
}

int __weak remove_section_mapping(unsigned long start, unsigned long end)
{
	return -ENODEV;
}

#define FLUSH_CHUNK_SIZE SZ_1G
/**
 * flush_dcache_range_chunked(): Write any modified data cache blocks out to
 * memory and invalidate them, in chunks of up to FLUSH_CHUNK_SIZE
 * Does not invalidate the corresponding instruction cache blocks.
 *
 * @start: the start address
 * @stop: the stop address (exclusive)
 * @chunk: the max size of the chunks
 */
static void flush_dcache_range_chunked(unsigned long start, unsigned long stop,
				       unsigned long chunk)
{
	unsigned long i;

	for (i = start; i < stop; i += chunk) {
		flush_dcache_range(i, min(stop, i + chunk));
		cond_resched();
	}
}

int __ref arch_add_memory(int nid, u64 start, u64 size,
			  struct mhp_params *params)
{
	unsigned long start_pfn = start >> PAGE_SHIFT;
	unsigned long nr_pages = size >> PAGE_SHIFT;
	int rc;

	start = (unsigned long)__va(start);
	rc = create_section_mapping(start, start + size, nid,
				    params->pgprot);
	if (rc) {
		pr_warn("Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n",
			start, start + size, rc);
		return -EFAULT;
	}

	return __add_pages(nid, start_pfn, nr_pages, params);
}

void __ref arch_remove_memory(int nid, u64 start, u64 size,
			     struct vmem_altmap *altmap)
{
	unsigned long start_pfn = start >> PAGE_SHIFT;
	unsigned long nr_pages = size >> PAGE_SHIFT;
	int ret;

	__remove_pages(start_pfn, nr_pages, altmap);

	/* Remove htab bolted mappings for this section of memory */
	start = (unsigned long)__va(start);
	flush_dcache_range_chunked(start, start + size, FLUSH_CHUNK_SIZE);

	ret = remove_section_mapping(start, start + size);
	WARN_ON_ONCE(ret);

	/* Ensure all vmalloc mappings are flushed in case they also
	 * hit that section of memory
	 */
	vm_unmap_aliases();
}
#endif

#ifndef CONFIG_NEED_MULTIPLE_NODES
void __init mem_topology_setup(void)
{
	max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
	min_low_pfn = MEMORY_START >> PAGE_SHIFT;
#ifdef CONFIG_HIGHMEM
	max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
#endif

	/* Place all memblock_regions in the same node and merge contiguous
	 * memblock_regions
	 */
	memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
}

void __init initmem_init(void)
{
	sparse_init();
}

/* mark pages that don't exist as nosave */
static int __init mark_nonram_nosave(void)
{
	struct memblock_region *reg, *prev = NULL;

	for_each_memblock(memory, reg) {
		if (prev &&
		    memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
			register_nosave_region(memblock_region_memory_end_pfn(prev),
					       memblock_region_memory_base_pfn(reg));
		prev = reg;
	}
	return 0;
}
#else /* CONFIG_NEED_MULTIPLE_NODES */
static int __init mark_nonram_nosave(void)
{
	return 0;
}
#endif

/*
 * Zones usage:
 *
 * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
 * everything else. GFP_DMA32 page allocations automatically fall back to
 * ZONE_DMA.
 *
 * By using 31-bit unconditionally, we can exploit zone_dma_bits to inform the
 * generic DMA mapping code.  32-bit only devices (if not handled by an IOMMU
 * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
 * ZONE_DMA.
 */
static unsigned long max_zone_pfns[MAX_NR_ZONES];

/*
 * paging_init() sets up the page tables - in fact we've already done this.
 */
void __init paging_init(void)
{
	unsigned long long total_ram = memblock_phys_mem_size();
	phys_addr_t top_of_ram = memblock_end_of_DRAM();

#ifdef CONFIG_HIGHMEM
	unsigned long v = __fix_to_virt(FIX_KMAP_END);
	unsigned long end = __fix_to_virt(FIX_KMAP_BEGIN);

	for (; v < end; v += PAGE_SIZE)
		map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */

	map_kernel_page(PKMAP_BASE, 0, __pgprot(0));	/* XXX gross */
	pkmap_page_table = virt_to_kpte(PKMAP_BASE);

	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
#endif /* CONFIG_HIGHMEM */

	printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
	       (unsigned long long)top_of_ram, total_ram);
	printk(KERN_DEBUG "Memory hole size: %ldMB\n",
	       (long int)((top_of_ram - total_ram) >> 20));

	/*
	 * Allow 30-bit DMA for very limited Broadcom wifi chips on many
	 * powerbooks.
	 */
	if (IS_ENABLED(CONFIG_PPC32))
		zone_dma_bits = 30;
	else
		zone_dma_bits = 31;

#ifdef CONFIG_ZONE_DMA
	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn,
				      1UL << (zone_dma_bits - PAGE_SHIFT));
#endif
	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
#ifdef CONFIG_HIGHMEM
	max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
#endif

	free_area_init(max_zone_pfns);

	mark_nonram_nosave();
}

void __init mem_init(void)
{
	/*
	 * book3s is limited to 16 page sizes due to encoding this in
	 * a 4-bit field for slices.
	 */