swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
Tip revision: e21a712a9685488f5ce80495b37b9fdbe96c230d authored by Linus Torvalds on 05 August 2019, 01:40:12 UTC
Linux 5.3-rc3
Linux 5.3-rc3
Tip revision: e21a712
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 <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 <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 <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);
pgprot_t kmap_prot;
EXPORT_SYMBOL(kmap_prot);
static inline pte_t *virt_to_kpte(unsigned long vaddr)
{
return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
vaddr), vaddr), vaddr);
}
#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)
{
return -ENODEV;
}
int __weak remove_section_mapping(unsigned long start, unsigned long end)
{
return -ENODEV;
}
int __ref arch_add_memory(int nid, u64 start, u64 size,
struct mhp_restrictions *restrictions)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
int rc;
resize_hpt_for_hotplug(memblock_phys_mem_size());
start = (unsigned long)__va(start);
rc = create_section_mapping(start, start + size, nid);
if (rc) {
pr_warn("Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n",
start, start + size, rc);
return -EFAULT;
}
flush_dcache_range(start, start + size);
return __add_pages(nid, start_pfn, nr_pages, restrictions);
}
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;
struct page *page = pfn_to_page(start_pfn) + vmem_altmap_offset(altmap);
int ret;
__remove_pages(page_zone(page), start_pfn, nr_pages, altmap);
/* Remove htab bolted mappings for this section of memory */
start = (unsigned long)__va(start);
flush_dcache_range(start, start + 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();
if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC)
pr_warn("Hash collision while resizing HPT\n");
}
#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)
{
/* XXX need to clip this if using highmem? */
sparse_memory_present_with_active_regions(0);
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 ARCH_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_PPC32
unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
unsigned long end = __fix_to_virt(FIX_HOLE);
for (; v < end; v += PAGE_SIZE)
map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
#endif
#ifdef CONFIG_HIGHMEM
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));
kmap_prot = PAGE_KERNEL;
#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));
#ifdef CONFIG_ZONE_DMA
max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
1UL << (ARCH_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_nodes(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.
*/
BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
#ifdef CONFIG_SWIOTLB
swiotlb_init(0);
#endif
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
set_max_mapnr(max_pfn);
memblock_free_all();
#ifdef CONFIG_HIGHMEM
{
unsigned long pfn, highmem_mapnr;
highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
struct page *page = pfn_to_page(pfn);
if (!memblock_is_reserved(paddr))
free_highmem_page(page);
}
}
#endif /* CONFIG_HIGHMEM */
#if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
/*
* If smp is enabled, next_tlbcam_idx is initialized in the cpu up
* functions.... do it here for the non-smp case.
*/
per_cpu(next_tlbcam_idx, smp_processor_id()) =
(mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
#endif
mem_init_print_info(NULL);
#ifdef CONFIG_PPC32
pr_info("Kernel virtual memory layout:\n");
#ifdef CONFIG_KASAN
pr_info(" * 0x%08lx..0x%08lx : kasan shadow mem\n",
KASAN_SHADOW_START, KASAN_SHADOW_END);
#endif
pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
#ifdef CONFIG_HIGHMEM
pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
#endif /* CONFIG_HIGHMEM */
#ifdef CONFIG_NOT_COHERENT_CACHE
pr_info(" * 0x%08lx..0x%08lx : consistent mem\n",
IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
#endif /* CONFIG_NOT_COHERENT_CACHE */
pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
ioremap_bot, IOREMAP_TOP);
pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
VMALLOC_START, VMALLOC_END);
#endif /* CONFIG_PPC32 */
}
void free_initmem(void)
{
ppc_md.progress = ppc_printk_progress;
mark_initmem_nx();
init_mem_is_free = true;
free_initmem_default(POISON_FREE_INITMEM);
}
/*
* This is called when a page has been modified by the kernel.
* It just marks the page as not i-cache clean. We do the i-cache
* flush later when the page is given to a user process, if necessary.
*/
void flush_dcache_page(struct page *page)
{
if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
return;
/* avoid an atomic op if possible */
if (test_bit(PG_arch_1, &page->flags))
clear_bit(PG_arch_1, &page->flags);
}
EXPORT_SYMBOL(flush_dcache_page);
void flush_dcache_icache_page(struct page *page)
{
#ifdef CONFIG_HUGETLB_PAGE
if (PageCompound(page)) {
flush_dcache_icache_hugepage(page);
return;
}
#endif
#if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC64)
/* On 8xx there is no need to kmap since highmem is not supported */
__flush_dcache_icache(page_address(page));
#else
if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
void *start = kmap_atomic(page);
__flush_dcache_icache(start);
kunmap_atomic(start);
} else {
__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
}
#endif
}
EXPORT_SYMBOL(flush_dcache_icache_page);
void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
{
clear_page(page);
/*
* We shouldn't have to do this, but some versions of glibc
* require it (ld.so assumes zero filled pages are icache clean)
* - Anton
*/
flush_dcache_page(pg);
}
EXPORT_SYMBOL(clear_user_page);
void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
struct page *pg)
{
copy_page(vto, vfrom);
/*
* We should be able to use the following optimisation, however
* there are two problems.
* Firstly a bug in some versions of binutils meant PLT sections
* were not marked executable.
* Secondly the first word in the GOT section is blrl, used
* to establish the GOT address. Until recently the GOT was
* not marked executable.
* - Anton
*/
#if 0
if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
return;
#endif
flush_dcache_page(pg);
}
void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
unsigned long addr, int len)
{
unsigned long maddr;
maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
flush_icache_range(maddr, maddr + len);
kunmap(page);
}
EXPORT_SYMBOL(flush_icache_user_range);
/*
* This is called at the end of handling a user page fault, when the
* fault has been handled by updating a PTE in the linux page tables.
* We use it to preload an HPTE into the hash table corresponding to
* the updated linux PTE.
*
* This must always be called with the pte lock held.
*/
void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
pte_t *ptep)
{
#ifdef CONFIG_PPC_BOOK3S
/*
* We don't need to worry about _PAGE_PRESENT here because we are
* called with either mm->page_table_lock held or ptl lock held
*/
unsigned long trap;
bool is_exec;
if (radix_enabled()) {
prefetch((void *)address);
return;
}
/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
if (!pte_young(*ptep) || address >= TASK_SIZE)
return;
/* We try to figure out if we are coming from an instruction
* access fault and pass that down to __hash_page so we avoid
* double-faulting on execution of fresh text. We have to test
* for regs NULL since init will get here first thing at boot
*
* We also avoid filling the hash if not coming from a fault
*/
trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL;
switch (trap) {
case 0x300:
is_exec = false;
break;
case 0x400:
is_exec = true;
break;
default:
return;
}
hash_preload(vma->vm_mm, address, is_exec, trap);
#endif /* CONFIG_PPC_BOOK3S */
#if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
&& defined(CONFIG_HUGETLB_PAGE)
if (is_vm_hugetlb_page(vma))
book3e_hugetlb_preload(vma, address, *ptep);
#endif
}
/*
* System memory should not be in /proc/iomem but various tools expect it
* (eg kdump).
*/
static int __init add_system_ram_resources(void)
{
struct memblock_region *reg;
for_each_memblock(memory, reg) {
struct resource *res;
unsigned long base = reg->base;
unsigned long size = reg->size;
res = kzalloc(sizeof(struct resource), GFP_KERNEL);
WARN_ON(!res);
if (res) {
res->name = "System RAM";
res->start = base;
res->end = base + size - 1;
res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
WARN_ON(request_resource(&iomem_resource, res) < 0);
}
}
return 0;
}
subsys_initcall(add_system_ram_resources);
#ifdef CONFIG_STRICT_DEVMEM
/*
* devmem_is_allowed(): check to see if /dev/mem access to a certain address
* is valid. The argument is a physical page number.
*
* Access has to be given to non-kernel-ram areas as well, these contain the
* PCI mmio resources as well as potential bios/acpi data regions.
*/
int devmem_is_allowed(unsigned long pfn)
{
if (page_is_rtas_user_buf(pfn))
return 1;
if (iomem_is_exclusive(PFN_PHYS(pfn)))
return 0;
if (!page_is_ram(pfn))
return 1;
return 0;
}
#endif /* CONFIG_STRICT_DEVMEM */
/*
* This is defined in kernel/resource.c but only powerpc needs to export it, for
* the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed.
*/
EXPORT_SYMBOL_GPL(walk_system_ram_range);