[mirror_ubuntu-eoan-kernel.git] / arch / powerpc / mm / init_64.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
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  Dave Engebretsen <engebret@us.ibm.com>
 *      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 <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/pgtable.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 <mm/mmu_decl.h>

phys_addr_t memstart_addr = ~0;
EXPORT_SYMBOL_GPL(memstart_addr);
phys_addr_t kernstart_addr;
EXPORT_SYMBOL_GPL(kernstart_addr);

#ifdef CONFIG_SPARSEMEM_VMEMMAP
/*
 * Given an address within the vmemmap, determine the pfn of the page that
 * represents the start of the section 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 unsigned long __meminit vmemmap_section_start(unsigned long page)
{
	unsigned long offset = page - ((unsigned long)(vmemmap));

	/* Return the pfn of the start of the section. */
	return (offset / sizeof(struct page)) & PAGE_SECTION_MASK;
}

/*
 * Check if this vmemmap page is already initialised.  If any section
 * which overlaps this vmemmap page is initialised then this page is
 * initialised already.
 */
static int __meminit vmemmap_populated(unsigned long start, int page_size)
{
	unsigned long end = start + page_size;
	start = (unsigned long)(pfn_to_page(vmemmap_section_start(start)));

	for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page)))
		if (pfn_valid(page_to_pfn((struct page *)start)))
			return 1;

	return 0;
}

/*
 * vmemmap virtual address space management does not have a traditonal 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 freeed 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 void 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)) {
		WARN_ON(1);
		return;
	}

	vmem_back->phys = phys;
	vmem_back->virt_addr = start;
	vmem_back->list = vmemmap_list;

	vmemmap_list = vmem_back;
}

static 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) > altmap->end_pfn)
		return true;

	if (start_pfn < altmap->base_pfn)
		return true;

	return false;
}

int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
		struct vmem_altmap *altmap)
{
	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;

		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 = altmap_alloc_block_buf(page_size, altmap);
			if (!p)
				pr_debug("altmap block allocation failed, falling back to system memory");
		}
		if (!p)
			p = vmemmap_alloc_block_buf(page_size, node);
		if (!p)
			return -ENOMEM;

		vmemmap_list_populate(__pa(p), start, node);

		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;
}

#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)) {
		WARN_ON(1);
		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;
}

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 + altmap->alloc + altmap->align;
	}

	pr_debug("vmemmap_free %lx...%lx\n", start, end);

	for (; start < end; start += page_size) {
		unsigned long nr_pages, addr;
		struct page *page;

		/*
		 * the section has already be marked as invalid, so
		 * vmemmap_populated() true means some other sections still
		 * in this page, so skip it.
		 */
		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);
	}
}
#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
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))) {
			pr_warn("WARNING: Hypervisor doesn't support RADIX with GTSE\n");
		}
		/* 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;
	}
}

void __init mmu_early_init_devtree(void)
{
	/* Disable radix mode based on kernel command line. */
	if (disable_radix)
		cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;

	/*
	 * 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 (!(mfmsr() & MSR_HV))
		early_check_vec5();

	if (early_radix_enabled())
		radix__early_init_devtree();
	else
		hash__early_init_devtree();
}
#endif /* CONFIG_PPC_BOOK3S_64 */
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* PowerPC version
	4	* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
	5	*
	6	* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
	7	* and Cort Dougan (PReP) (cort@cs.nmt.edu)
	8	* Copyright (C) 1996 Paul Mackerras
	9	*
	10	* Derived from "arch/i386/mm/init.c"
	11	* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
	12	*
	13	* Dave Engebretsen <engebret@us.ibm.com>
	14	* Rework for PPC64 port.
	15	*/
	16
	17	#undef DEBUG
	18
	19	#include <linux/signal.h>
	20	#include <linux/sched.h>
	21	#include <linux/kernel.h>
	22	#include <linux/errno.h>
	23	#include <linux/string.h>
	24	#include <linux/types.h>
	25	#include <linux/mman.h>
	26	#include <linux/mm.h>
	27	#include <linux/swap.h>
	28	#include <linux/stddef.h>
	29	#include <linux/vmalloc.h>
	30	#include <linux/init.h>
	31	#include <linux/delay.h>
	32	#include <linux/highmem.h>
	33	#include <linux/idr.h>
	34	#include <linux/nodemask.h>
	35	#include <linux/module.h>
	36	#include <linux/poison.h>
	37	#include <linux/memblock.h>
	38	#include <linux/hugetlb.h>
	39	#include <linux/slab.h>
	40	#include <linux/of_fdt.h>
	41	#include <linux/libfdt.h>
	42	#include <linux/memremap.h>
	43
	44	#include <asm/pgalloc.h>
	45	#include <asm/page.h>
	46	#include <asm/prom.h>
	47	#include <asm/rtas.h>
	48	#include <asm/io.h>
	49	#include <asm/mmu_context.h>
	50	#include <asm/pgtable.h>
	51	#include <asm/mmu.h>
	52	#include <linux/uaccess.h>
	53	#include <asm/smp.h>
	54	#include <asm/machdep.h>
	55	#include <asm/tlb.h>
	56	#include <asm/eeh.h>
	57	#include <asm/processor.h>
	58	#include <asm/mmzone.h>
	59	#include <asm/cputable.h>
	60	#include <asm/sections.h>
	61	#include <asm/iommu.h>
	62	#include <asm/vdso.h>
	63
	64	#include <mm/mmu_decl.h>
	65
	66	phys_addr_t memstart_addr = ~0;
	67	EXPORT_SYMBOL_GPL(memstart_addr);
	68	phys_addr_t kernstart_addr;
	69	EXPORT_SYMBOL_GPL(kernstart_addr);
	70
	71	#ifdef CONFIG_SPARSEMEM_VMEMMAP
	72	/*
	73	* Given an address within the vmemmap, determine the pfn of the page that
	74	* represents the start of the section it is within. Note that we have to
	75	* do this by hand as the proffered address may not be correctly aligned.
	76	* Subtraction of non-aligned pointers produces undefined results.
	77	*/
	78	static unsigned long __meminit vmemmap_section_start(unsigned long page)
	79	{
	80	unsigned long offset = page - ((unsigned long)(vmemmap));
	81
	82	/* Return the pfn of the start of the section. */
	83	return (offset / sizeof(struct page)) & PAGE_SECTION_MASK;
	84	}
	85
	86	/*
	87	* Check if this vmemmap page is already initialised. If any section
	88	* which overlaps this vmemmap page is initialised then this page is
	89	* initialised already.
	90	*/
	91	static int __meminit vmemmap_populated(unsigned long start, int page_size)
	92	{
	93	unsigned long end = start + page_size;
	94	start = (unsigned long)(pfn_to_page(vmemmap_section_start(start)));
	95
	96	for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page)))
	97	if (pfn_valid(page_to_pfn((struct page *)start)))
	98	return 1;
	99
	100	return 0;
	101	}
	102
	103	/*
	104	* vmemmap virtual address space management does not have a traditonal page
	105	* table to track which virtual struct pages are backed by physical mapping.
	106	* The virtual to physical mappings are tracked in a simple linked list
	107	* format. 'vmemmap_list' maintains the entire vmemmap physical mapping at
	108	* all times where as the 'next' list maintains the available
	109	* vmemmap_backing structures which have been deleted from the
	110	* 'vmemmap_global' list during system runtime (memory hotplug remove
	111	* operation). The freed 'vmemmap_backing' structures are reused later when
	112	* new requests come in without allocating fresh memory. This pointer also
	113	* tracks the allocated 'vmemmap_backing' structures as we allocate one
	114	* full page memory at a time when we dont have any.
	115	*/
	116	struct vmemmap_backing *vmemmap_list;
	117	static struct vmemmap_backing *next;
	118
	119	/*
	120	* The same pointer 'next' tracks individual chunks inside the allocated
	121	* full page during the boot time and again tracks the freeed nodes during
	122	* runtime. It is racy but it does not happen as they are separated by the
	123	* boot process. Will create problem if some how we have memory hotplug
	124	* operation during boot !!
	125	*/
	126	static int num_left;
	127	static int num_freed;
	128
	129	static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node)
	130	{
	131	struct vmemmap_backing *vmem_back;
	132	/* get from freed entries first */
	133	if (num_freed) {
	134	num_freed--;
	135	vmem_back = next;
	136	next = next->list;
	137
	138	return vmem_back;
	139	}
	140
	141	/* allocate a page when required and hand out chunks */
	142	if (!num_left) {
	143	next = vmemmap_alloc_block(PAGE_SIZE, node);
	144	if (unlikely(!next)) {
	145	WARN_ON(1);
	146	return NULL;
	147	}
	148	num_left = PAGE_SIZE / sizeof(struct vmemmap_backing);
	149	}
	150
	151	num_left--;
	152
	153	return next++;
	154	}
	155
	156	static __meminit void vmemmap_list_populate(unsigned long phys,
	157	unsigned long start,
	158	int node)
	159	{
	160	struct vmemmap_backing *vmem_back;
	161
	162	vmem_back = vmemmap_list_alloc(node);
	163	if (unlikely(!vmem_back)) {
	164	WARN_ON(1);
	165	return;
	166	}
	167
	168	vmem_back->phys = phys;
	169	vmem_back->virt_addr = start;
	170	vmem_back->list = vmemmap_list;
	171
	172	vmemmap_list = vmem_back;
	173	}
	174
	175	static bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long start,
	176	unsigned long page_size)
	177	{
	178	unsigned long nr_pfn = page_size / sizeof(struct page);
	179	unsigned long start_pfn = page_to_pfn((struct page *)start);
	180
	181	if ((start_pfn + nr_pfn) > altmap->end_pfn)
	182	return true;
	183
	184	if (start_pfn < altmap->base_pfn)
	185	return true;
	186
	187	return false;
	188	}
	189
	190	int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
	191	struct vmem_altmap *altmap)
	192	{
	193	unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
	194
	195	/* Align to the page size of the linear mapping. */
	196	start = _ALIGN_DOWN(start, page_size);
	197
	198	pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node);
	199
	200	for (; start < end; start += page_size) {
	201	void *p = NULL;
	202	int rc;
	203
	204	if (vmemmap_populated(start, page_size))
	205	continue;
	206
	207	/*
	208	* Allocate from the altmap first if we have one. This may
	209	* fail due to alignment issues when using 16MB hugepages, so
	210	* fall back to system memory if the altmap allocation fail.
	211	*/
	212	if (altmap && !altmap_cross_boundary(altmap, start, page_size)) {
	213	p = altmap_alloc_block_buf(page_size, altmap);
	214	if (!p)
	215	pr_debug("altmap block allocation failed, falling back to system memory");
	216	}
	217	if (!p)
	218	p = vmemmap_alloc_block_buf(page_size, node);
	219	if (!p)
	220	return -ENOMEM;
	221
	222	vmemmap_list_populate(__pa(p), start, node);
	223
	224	pr_debug(" * %016lx..%016lx allocated at %p\n",
	225	start, start + page_size, p);
	226
	227	rc = vmemmap_create_mapping(start, page_size, __pa(p));
	228	if (rc < 0) {
	229	pr_warn("%s: Unable to create vmemmap mapping: %d\n",
	230	__func__, rc);
	231	return -EFAULT;
	232	}
	233	}
	234
	235	return 0;
	236	}
	237
	238	#ifdef CONFIG_MEMORY_HOTPLUG
	239	static unsigned long vmemmap_list_free(unsigned long start)
	240	{
	241	struct vmemmap_backing vmem_back, vmem_back_prev;
	242
	243	vmem_back_prev = vmem_back = vmemmap_list;
	244
	245	/* look for it with prev pointer recorded */
	246	for (; vmem_back; vmem_back = vmem_back->list) {
	247	if (vmem_back->virt_addr == start)
	248	break;
	249	vmem_back_prev = vmem_back;
	250	}
	251
	252	if (unlikely(!vmem_back)) {
	253	WARN_ON(1);
	254	return 0;
	255	}
	256
	257	/* remove it from vmemmap_list */
	258	if (vmem_back == vmemmap_list) /* remove head */
	259	vmemmap_list = vmem_back->list;
	260	else
	261	vmem_back_prev->list = vmem_back->list;
	262
	263	/* next point to this freed entry */
	264	vmem_back->list = next;
	265	next = vmem_back;
	266	num_freed++;
	267
	268	return vmem_back->phys;
	269	}
	270
	271	void __ref vmemmap_free(unsigned long start, unsigned long end,
	272	struct vmem_altmap *altmap)
	273	{
	274	unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
	275	unsigned long page_order = get_order(page_size);
	276	unsigned long alt_start = ~0, alt_end = ~0;
	277	unsigned long base_pfn;
	278
	279	start = _ALIGN_DOWN(start, page_size);
	280	if (altmap) {
	281	alt_start = altmap->base_pfn;
	282	alt_end = altmap->base_pfn + altmap->reserve +
	283	altmap->free + altmap->alloc + altmap->align;
	284	}
	285
	286	pr_debug("vmemmap_free %lx...%lx\n", start, end);
	287
	288	for (; start < end; start += page_size) {
	289	unsigned long nr_pages, addr;
	290	struct page *page;
	291
	292	/*
	293	* the section has already be marked as invalid, so
	294	* vmemmap_populated() true means some other sections still
	295	* in this page, so skip it.
	296	*/
	297	if (vmemmap_populated(start, page_size))
	298	continue;
	299
	300	addr = vmemmap_list_free(start);
	301	if (!addr)
	302	continue;
	303
	304	page = pfn_to_page(addr >> PAGE_SHIFT);
	305	nr_pages = 1 << page_order;
	306	base_pfn = PHYS_PFN(addr);
	307
	308	if (base_pfn >= alt_start && base_pfn < alt_end) {
	309	vmem_altmap_free(altmap, nr_pages);
	310	} else if (PageReserved(page)) {
	311	/* allocated from bootmem */
	312	if (page_size < PAGE_SIZE) {
	313	/*
	314	* this shouldn't happen, but if it is
	315	* the case, leave the memory there
	316	*/
	317	WARN_ON_ONCE(1);
	318	} else {
	319	while (nr_pages--)
	320	free_reserved_page(page++);
	321	}
	322	} else {
	323	free_pages((unsigned long)(__va(addr)), page_order);
	324	}
	325
	326	vmemmap_remove_mapping(start, page_size);
	327	}
	328	}
	329	#endif
	330	void register_page_bootmem_memmap(unsigned long section_nr,
	331	struct page *start_page, unsigned long size)
	332	{
	333	}
	334
	335	#endif /* CONFIG_SPARSEMEM_VMEMMAP */
	336
	337	#ifdef CONFIG_PPC_BOOK3S_64
	338	static bool disable_radix = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT);
	339
	340	static int __init parse_disable_radix(char *p)
	341	{
	342	bool val;
	343
	344	if (!p)
	345	val = true;
	346	else if (kstrtobool(p, &val))
	347	return -EINVAL;
	348
	349	disable_radix = val;
	350
	351	return 0;
	352	}
	353	early_param("disable_radix", parse_disable_radix);
	354
	355	/*
	356	* If we're running under a hypervisor, we need to check the contents of
	357	* /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do
	358	* radix. If not, we clear the radix feature bit so we fall back to hash.
	359	*/
	360	static void __init early_check_vec5(void)
	361	{
	362	unsigned long root, chosen;
	363	int size;
	364	const u8 *vec5;
	365	u8 mmu_supported;
	366
	367	root = of_get_flat_dt_root();
	368	chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
	369	if (chosen == -FDT_ERR_NOTFOUND) {
	370	cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
	371	return;
	372	}
	373	vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size);
	374	if (!vec5) {
	375	cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
	376	return;
	377	}
	378	if (size <= OV5_INDX(OV5_MMU_SUPPORT)) {
	379	cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
	380	return;
	381	}
	382
	383	/* Check for supported configuration */
	384	mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] &
	385	OV5_FEAT(OV5_MMU_SUPPORT);
	386	if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) {
	387	/* Hypervisor only supports radix - check enabled && GTSE */
	388	if (!early_radix_enabled()) {
	389	pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
	390	}
	391	if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] &
	392	OV5_FEAT(OV5_RADIX_GTSE))) {
	393	pr_warn("WARNING: Hypervisor doesn't support RADIX with GTSE\n");
	394	}
	395	/* Do radix anyway - the hypervisor said we had to */
	396	cur_cpu_spec->mmu_features \|= MMU_FTR_TYPE_RADIX;
	397	} else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) {
	398	/* Hypervisor only supports hash - disable radix */
	399	cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
	400	}
	401	}
	402
	403	void __init mmu_early_init_devtree(void)
	404	{
	405	/* Disable radix mode based on kernel command line. */
	406	if (disable_radix)
	407	cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
	408
	409	/*
	410	* Check /chosen/ibm,architecture-vec-5 if running as a guest.
	411	* When running bare-metal, we can use radix if we like
	412	* even though the ibm,architecture-vec-5 property created by
	413	* skiboot doesn't have the necessary bits set.
	414	*/
	415	if (!(mfmsr() & MSR_HV))
	416	early_check_vec5();
	417
	418	if (early_radix_enabled())
	419	radix__early_init_devtree();
	420	else
	421	hash__early_init_devtree();
	422	}
	423	#endif /* CONFIG_PPC_BOOK3S_64 */