// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas ([email protected])
*
* Modifications by Paul Mackerras (PowerMac) ([email protected])
* and Cort Dougan (PReP) ([email protected])
* Copyright (C) 1996 Paul Mackerras
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*
* Dave Engebretsen <[email protected]>
* Rework for PPC64 port.
*/
#undef DEBUG
#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/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/idr.h>
#include <linux/nodemask.h>
#include <linux/module.h>
#include <linux/poison.h>
#include <linux/memblock.h>
#include <linux/hugetlb.h>
#include <linux/slab.h>
#include <linux/of_fdt.h>
#include <linux/libfdt.h>
#include <linux/memremap.h>
#include <linux/memory.h>
#include <asm/pgalloc.h>
#include <asm/page.h>
#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/mmu.h>
#include <linux/uaccess.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/tlb.h>
#include <asm/eeh.h>
#include <asm/processor.h>
#include <asm/mmzone.h>
#include <asm/cputable.h>
#include <asm/sections.h>
#include <asm/iommu.h>
#include <asm/vdso.h>
#include <asm/hugetlb.h>
#include <mm/mmu_decl.h>
#ifdef CONFIG_SPARSEMEM_VMEMMAP
/*
* Given an address within the vmemmap, determine the page that
* represents the start of the subsection it is within. Note that we have to
* do this by hand as the proffered address may not be correctly aligned.
* Subtraction of non-aligned pointers produces undefined results.
*/
static struct page * __meminit vmemmap_subsection_start(unsigned long vmemmap_addr)
{
unsigned long start_pfn;
unsigned long offset = vmemmap_addr - ((unsigned long)(vmemmap));
/* Return the pfn of the start of the section. */
start_pfn = (offset / sizeof(struct page)) & PAGE_SUBSECTION_MASK;
return pfn_to_page(start_pfn);
}
/*
* Since memory is added in sub-section chunks, before creating a new vmemmap
* mapping, the kernel should check whether there is an existing memmap mapping
* covering the new subsection added. This is needed because kernel can map
* vmemmap area using 16MB pages which will cover a memory range of 16G. Such
* a range covers multiple subsections (2M)
*
* If any subsection in the 16G range mapped by vmemmap is valid we consider the
* vmemmap populated (There is a page table entry already present). We can't do
* a page table lookup here because with the hash translation we don't keep
* vmemmap details in linux page table.
*/
int __meminit vmemmap_populated(unsigned long vmemmap_addr, int vmemmap_map_size)
{
struct page *start;
unsigned long vmemmap_end = vmemmap_addr + vmemmap_map_size;
start = vmemmap_subsection_start(vmemmap_addr);
for (; (unsigned long)start < vmemmap_end; start += PAGES_PER_SUBSECTION)
/*
* pfn valid check here is intended to really check
* whether we have any subsection already initialized
* in this range.
*/
if (pfn_valid(page_to_pfn(start)))
return 1;
return 0;
}
/*
* vmemmap virtual address space management does not have a traditional page
* table to track which virtual struct pages are backed by physical mapping.
* The virtual to physical mappings are tracked in a simple linked list
* format. 'vmemmap_list' maintains the entire vmemmap physical mapping at
* all times where as the 'next' list maintains the available
* vmemmap_backing structures which have been deleted from the
* 'vmemmap_global' list during system runtime (memory hotplug remove
* operation). The freed 'vmemmap_backing' structures are reused later when
* new requests come in without allocating fresh memory. This pointer also
* tracks the allocated 'vmemmap_backing' structures as we allocate one
* full page memory at a time when we dont have any.
*/
struct vmemmap_backing *vmemmap_list;
static struct vmemmap_backing *next;
/*
* The same pointer 'next' tracks individual chunks inside the allocated
* full page during the boot time and again tracks the freed nodes during
* runtime. It is racy but it does not happen as they are separated by the
* boot process. Will create problem if some how we have memory hotplug
* operation during boot !!
*/
static int num_left;
static int num_freed;
static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node)
{
struct vmemmap_backing *vmem_back;
/* get from freed entries first */
if (num_freed) {
num_freed--;
vmem_back = next;
next = next->list;
return vmem_back;
}
/* allocate a page when required and hand out chunks */
if (!num_left) {
next = vmemmap_alloc_block(PAGE_SIZE, node);
if (unlikely(!next)) {
WARN_ON(1);
return NULL;
}
num_left = PAGE_SIZE / sizeof(struct vmemmap_backing);
}
num_left--;
return next++;
}
static __meminit int vmemmap_list_populate(unsigned long phys,
unsigned long start,
int node)
{
struct vmemmap_backing *vmem_back;
vmem_back = vmemmap_list_alloc(node);
if (unlikely(!vmem_back)) {
pr_debug("vmemap list allocation failed\n");
return -ENOMEM;
}
vmem_back->phys = phys;
vmem_back->virt_addr = start;
vmem_back->list = vmemmap_list;
vmemmap_list = vmem_back;
return 0;
}
bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long start,
unsigned long page_size)
{
unsigned long nr_pfn = page_size / sizeof(struct page);
unsigned long start_pfn = page_to_pfn((struct page *)start);
if ((start_pfn + nr_pfn - 1) > altmap->end_pfn)
return true;
if (start_pfn < altmap->base_pfn)
return true;
return false;
}
static int __meminit __vmemmap_populate(unsigned long start, unsigned long end, int node,
struct vmem_altmap *altmap)
{
bool altmap_alloc;
unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
/* Align to the page size of the linear mapping. */
start = ALIGN_DOWN(start, page_size);
pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node);
for (; start < end; start += page_size) {
void *p = NULL;
int rc;
/*
* This vmemmap range is backing different subsections. If any
* of that subsection is marked valid, that means we already
* have initialized a page table covering this range and hence
* the vmemmap range is populated.
*/
if (vmemmap_populated(start, page_size))
continue;
/*
* Allocate from the altmap first if we have one. This may
* fail due to alignment issues when using 16MB hugepages, so
* fall back to system memory if the altmap allocation fail.
*/
if (altmap && !altmap_cross_boundary(altmap, start, page_size)) {
p = vmemmap_alloc_block_buf(page_size, node, altmap);
if (!p)
pr_debug("altmap block allocation failed, falling back to system memory");
else
altmap_alloc = true;
}
if (!p) {
p = vmemmap_alloc_block_buf(page_size, node, NULL);
altmap_alloc = false;
}
if (!p)
return -ENOMEM;
if (vmemmap_list_populate(__pa(p), start, node)) {
/*
* If we don't populate vmemap list, we don't have
* the ability to free the allocated vmemmap
* pages in section_deactivate. Hence free them
* here.
*/
int nr_pfns = page_size >> PAGE_SHIFT;
unsigned long page_order = get_order(page_size);
if (altmap_alloc)
vmem_altmap_free(altmap, nr_pfns);
else
free_pages((unsigned long)p, page_order);
return -ENOMEM;
}
pr_debug(" * %016lx..%016lx allocated at %p\n",
start, start + page_size, p);
rc = vmemmap_create_mapping(start, page_size, __pa(p));
if (rc < 0) {
pr_warn("%s: Unable to create vmemmap mapping: %d\n",
__func__, rc);
return -EFAULT;
}
}
return 0;
}
int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
struct vmem_altmap *altmap)
{
#ifdef CONFIG_PPC_BOOK3S_64
if (radix_enabled())
return radix__vmemmap_populate(start, end, node, altmap);
#endif
return __vmemmap_populate(start, end, node, altmap);
}
#ifdef CONFIG_MEMORY_HOTPLUG
static unsigned long vmemmap_list_free(unsigned long start)
{
struct vmemmap_backing *vmem_back, *vmem_back_prev;
vmem_back_prev = vmem_back = vmemmap_list;
/* look for it with prev pointer recorded */
for (; vmem_back; vmem_back = vmem_back->list) {
if (vmem_back->virt_addr == start)
break;
vmem_back_prev = vmem_back;
}
if (unlikely(!vmem_back))
return 0;
/* remove it from vmemmap_list */
if (vmem_back == vmemmap_list) /* remove head */
vmemmap_list = vmem_back->list;
else
vmem_back_prev->list = vmem_back->list;
/* next point to this freed entry */
vmem_back->list = next;
next = vmem_back;
num_freed++;
return vmem_back->phys;
}
static void __ref __vmemmap_free(unsigned long start, unsigned long end,
struct vmem_altmap *altmap)
{
unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
unsigned long page_order = get_order(page_size);
unsigned long alt_start = ~0, alt_end = ~0;
unsigned long base_pfn;
start = ALIGN_DOWN(start, page_size);
if (altmap) {
alt_start = altmap->base_pfn;
alt_end = altmap->base_pfn + altmap->reserve + altmap->free;
}
pr_debug("vmemmap_free %lx...%lx\n", start, end);
for (; start < end; start += page_size) {
unsigned long nr_pages, addr;
struct page *page;
/*
* We have already marked the subsection we are trying to remove
* invalid. So if we want to remove the vmemmap range, we
* need to make sure there is no subsection marked valid
* in this range.
*/
if (vmemmap_populated(start, page_size))
continue;
addr = vmemmap_list_free(start);
if (!addr)
continue;
page = pfn_to_page(addr >> PAGE_SHIFT);
nr_pages = 1 << page_order;
base_pfn = PHYS_PFN(addr);
if (base_pfn >= alt_start && base_pfn < alt_end) {
vmem_altmap_free(altmap, nr_pages);
} else if (PageReserved(page)) {
/* allocated from bootmem */
if (page_size < PAGE_SIZE) {
/*
* this shouldn't happen, but if it is
* the case, leave the memory there
*/
WARN_ON_ONCE(1);
} else {
while (nr_pages--)
free_reserved_page(page++);
}
} else {
free_pages((unsigned long)(__va(addr)), page_order);
}
vmemmap_remove_mapping(start, page_size);
}
}
void __ref vmemmap_free(unsigned long start, unsigned long end,
struct vmem_altmap *altmap)
{
#ifdef CONFIG_PPC_BOOK3S_64
if (radix_enabled())
return radix__vmemmap_free(start, end, altmap);
#endif
return __vmemmap_free(start, end, altmap);
}
#endif
void register_page_bootmem_memmap(unsigned long section_nr,
struct page *start_page, unsigned long size)
{
}
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
#ifdef CONFIG_PPC_BOOK3S_64
unsigned int mmu_lpid_bits;
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
EXPORT_SYMBOL_GPL(mmu_lpid_bits);
#endif
unsigned int mmu_pid_bits;
static bool disable_radix = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT);
static int __init parse_disable_radix(char *p)
{
bool val;
if (!p)
val = true;
else if (kstrtobool(p, &val))
return -EINVAL;
disable_radix = val;
return 0;
}
early_param("disable_radix", parse_disable_radix);
/*
* If we're running under a hypervisor, we need to check the contents of
* /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do
* radix. If not, we clear the radix feature bit so we fall back to hash.
*/
static void __init early_check_vec5(void)
{
unsigned long root, chosen;
int size;
const u8 *vec5;
u8 mmu_supported;
root = of_get_flat_dt_root();
chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
if (chosen == -FDT_ERR_NOTFOUND) {
cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
return;
}
vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size);
if (!vec5) {
cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
return;
}
if (size <= OV5_INDX(OV5_MMU_SUPPORT)) {
cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
return;
}
/* Check for supported configuration */
mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] &
OV5_FEAT(OV5_MMU_SUPPORT);
if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) {
/* Hypervisor only supports radix - check enabled && GTSE */
if (!early_radix_enabled()) {
pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
}
if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] &
OV5_FEAT(OV5_RADIX_GTSE))) {
cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
} else
cur_cpu_spec->mmu_features |= MMU_FTR_GTSE;
/* Do radix anyway - the hypervisor said we had to */
cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
} else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) {
/* Hypervisor only supports hash - disable radix */
cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
}
}
static int __init dt_scan_mmu_pid_width(unsigned long node,
const char *uname, int depth,
void *data)
{
int size = 0;
const __be32 *prop;
const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
/* We are scanning "cpu" nodes only */
if (type == NULL || strcmp(type, "cpu") != 0)
return 0;
/* Find MMU LPID, PID register size */
prop = of_get_flat_dt_prop(node, "ibm,mmu-lpid-bits", &size);
if (prop && size == 4)
mmu_lpid_bits = be32_to_cpup(prop);
prop = of_get_flat_dt_prop(node, "ibm,mmu-pid-bits", &size);
if (prop && size == 4)
mmu_pid_bits = be32_to_cpup(prop);
if (!mmu_pid_bits && !mmu_lpid_bits)
return 0;
return 1;
}
/*
* Outside hotplug the kernel uses this value to map the kernel direct map
* with radix. To be compatible with older kernels, let's keep this value
* as 16M which is also SECTION_SIZE with SPARSEMEM. We can ideally map
* things with 1GB size in the case where we don't support hotplug.
*/
#ifndef CONFIG_MEMORY_HOTPLUG
#define DEFAULT_MEMORY_BLOCK_SIZE SZ_16M
#else
#define DEFAULT_MEMORY_BLOCK_SIZE MIN_MEMORY_BLOCK_SIZE
#endif
static void update_memory_block_size(unsigned long *block_size, unsigned long mem_size)
{
unsigned long min_memory_block_size = DEFAULT_MEMORY_BLOCK_SIZE;
for (; *block_size > min_memory_block_size; *block_size >>= 2) {
if ((mem_size & *block_size) == 0)
break;
}
}
static int __init probe_memory_block_size(unsigned long node, const char *uname, int
depth, void *data)
{
const char *type;
unsigned long *block_size = (unsigned long *)data;
const __be32 *reg, *endp;
int l;
if (depth != 1)
return 0;
/*
* If we have dynamic-reconfiguration-memory node, use the
* lmb value.
*/
if (strcmp(uname, "ibm,dynamic-reconfiguration-memory") == 0) {
const __be32 *prop;
prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &l);
if (!prop || l < dt_root_size_cells * sizeof(__be32))
/*
* Nothing in the device tree
*/
*block_size = DEFAULT_MEMORY_BLOCK_SIZE;
else
*block_size = of_read_number(prop, dt_root_size_cells);
/*
* We have found the final value. Don't probe further.
*/
return 1;
}
/*
* Find all the device tree nodes of memory type and make sure
* the area can be mapped using the memory block size value
* we end up using. We start with 1G value and keep reducing
* it such that we can map the entire area using memory_block_size.
* This will be used on powernv and older pseries that don't
* have ibm,lmb-size node.
* For ex: with P5 we can end up with
* memory@0 -> 128MB
* memory@128M -> 64M
* This will end up using 64MB memory block size value.
*/
type = of_get_flat_dt_prop(node, "device_type", NULL);
if (type == NULL || strcmp(type, "memory") != 0)
return 0;
reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
if (!reg)
reg = of_get_flat_dt_prop(node, "reg", &l);
if (!reg)
return 0;
endp = reg + (l / sizeof(__be32));
while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
const char *compatible;
u64 size;
dt_mem_next_cell(dt_root_addr_cells, ®);
size = dt_mem_next_cell(dt_root_size_cells, ®);
if (size) {
update_memory_block_size(block_size, size);
continue;
}
/*
* ibm,coherent-device-memory with linux,usable-memory = 0
* Force 256MiB block size. Work around for GPUs on P9 PowerNV
* linux,usable-memory == 0 implies driver managed memory and
* we can't use large memory block size due to hotplug/unplug
* limitations.
*/
compatible = of_get_flat_dt_prop(node, "compatible", NULL);
if (compatible && !strcmp(compatible, "ibm,coherent-device-memory")) {
if (*block_size > SZ_256M)
*block_size = SZ_256M;
/*
* We keep 256M as the upper limit with GPU present.
*/
return 0;
}
}
/* continue looking for other memory device types */
return 0;
}
/*
* start with 1G memory block size. Early init will
* fix this with correct value.
*/
unsigned long memory_block_size __ro_after_init = 1UL << 30;
static void __init early_init_memory_block_size(void)
{
/*
* We need to do memory_block_size probe early so that
* radix__early_init_mmu() can use this as limit for
* mapping page size.
*/
of_scan_flat_dt(probe_memory_block_size, &memory_block_size);
}
void __init mmu_early_init_devtree(void)
{
bool hvmode = !!(mfmsr() & MSR_HV);
/* Disable radix mode based on kernel command line. */
if (disable_radix) {
if (IS_ENABLED(CONFIG_PPC_64S_HASH_MMU))
cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
else
pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
}
of_scan_flat_dt(dt_scan_mmu_pid_width, NULL);
if (hvmode && !mmu_lpid_bits) {
if (early_cpu_has_feature(CPU_FTR_ARCH_207S))
mmu_lpid_bits = 12; /* POWER8-10 */
else
mmu_lpid_bits = 10; /* POWER7 */
}
if (!mmu_pid_bits) {
if (early_cpu_has_feature(CPU_FTR_ARCH_300))
mmu_pid_bits = 20; /* POWER9-10 */
}
/*
* Check /chosen/ibm,architecture-vec-5 if running as a guest.
* When running bare-metal, we can use radix if we like
* even though the ibm,architecture-vec-5 property created by
* skiboot doesn't have the necessary bits set.
*/
if (!hvmode)
early_check_vec5();
early_init_memory_block_size();
if (early_radix_enabled()) {
radix__early_init_devtree();
/*
* We have finalized the translation we are going to use by now.
* Radix mode is not limited by RMA / VRMA addressing.
* Hence don't limit memblock allocations.
*/
ppc64_rma_size = ULONG_MAX;
memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
} else
hash__early_init_devtree();
if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE))
hugetlbpage_init_defaultsize();
if (!(cur_cpu_spec->mmu_features & MMU_FTR_HPTE_TABLE) &&
!(cur_cpu_spec->mmu_features & MMU_FTR_TYPE_RADIX))
panic("kernel does not support any MMU type offered by platform");
}
#endif /* CONFIG_PPC_BOOK3S_64 */
Codebase Browser
linux