Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 * Virtual Memory Map support
 *
 * (C) 2007 sgi. Christoph Lameter.
 *
 * Virtual memory maps allow VM primitives pfn_to_page, page_to_pfn,
 * virt_to_page, page_address() to be implemented as a base offset
 * calculation without memory access.
 *
 * However, virtual mappings need a page table and TLBs. Many Linux
 * architectures already map their physical space using 1-1 mappings
 * via TLBs. For those arches the virtual memory map is essentially
 * for free if we use the same page size as the 1-1 mappings. In that
 * case the overhead consists of a few additional pages that are
 * allocated to create a view of memory for vmemmap.
 *
 * The architecture is expected to provide a vmemmap_populate() function
 * to instantiate the mapping.
 */
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/memblock.h>
#include <linux/memremap.h>
#include <linux/highmem.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <linux/sched.h>
#include <asm/dma.h>
#include <asm/pgalloc.h>
 
/*
 * Allocate a block of memory to be used to back the virtual memory map
 * or to back the page tables that are used to create the mapping.
 * Uses the main allocators if they are available, else bootmem.
 */
 
static void * __ref __earlyonly_bootmem_alloc(int node,
<------><------><------><------>unsigned long size,
<------><------><------><------>unsigned long align,
<------><------><------><------>unsigned long goal)
{
<------>return memblock_alloc_try_nid_raw(size, align, goal,
<------><------><------><------><------>       MEMBLOCK_ALLOC_ACCESSIBLE, node);
}
 
void * __meminit vmemmap_alloc_block(unsigned long size, int node)
{
<------>/* If the main allocator is up use that, fallback to bootmem. */
<------>if (slab_is_available()) {
<------><------>gfp_t gfp_mask = GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_NOWARN;
<------><------>int order = get_order(size);
<------><------>static bool warned;
<------><------>struct page *page;
 
<------><------>page = alloc_pages_node(node, gfp_mask, order);
<------><------>if (page)
<------><------><------>return page_address(page);
 
<------><------>if (!warned) {
<------><------><------>warn_alloc(gfp_mask & ~__GFP_NOWARN, NULL,
<------><------><------><------>   "vmemmap alloc failure: order:%u", order);
<------><------><------>warned = true;
<------><------>}
<------><------>return NULL;
<------>} else
<------><------>return __earlyonly_bootmem_alloc(node, size, size,
<------><------><------><------>__pa(MAX_DMA_ADDRESS));
}
 
static void * __meminit altmap_alloc_block_buf(unsigned long size,
<------><------><------><------><------>       struct vmem_altmap *altmap);
 
/* need to make sure size is all the same during early stage */
void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node,
<------><------><------><------><------> struct vmem_altmap *altmap)
{
<------>void *ptr;
 
<------>if (altmap)
<------><------>return altmap_alloc_block_buf(size, altmap);
 
<------>ptr = sparse_buffer_alloc(size);
<------>if (!ptr)
<------><------>ptr = vmemmap_alloc_block(size, node);
<------>return ptr;
}
 
static unsigned long __meminit vmem_altmap_next_pfn(struct vmem_altmap *altmap)
{
<------>return altmap->base_pfn + altmap->reserve + altmap->alloc
<------><------>+ altmap->align;
}
 
static unsigned long __meminit vmem_altmap_nr_free(struct vmem_altmap *altmap)
{
<------>unsigned long allocated = altmap->alloc + altmap->align;
 
<------>if (altmap->free > allocated)
<------><------>return altmap->free - allocated;
<------>return 0;
}
 
static void * __meminit altmap_alloc_block_buf(unsigned long size,
<------><------><------><------><------>       struct vmem_altmap *altmap)
{
<------>unsigned long pfn, nr_pfns, nr_align;
 
<------>if (size & ~PAGE_MASK) {
<------><------>pr_warn_once("%s: allocations must be multiple of PAGE_SIZE (%ld)\n",
<------><------><------><------>__func__, size);
<------><------>return NULL;
<------>}
 
<------>pfn = vmem_altmap_next_pfn(altmap);
<------>nr_pfns = size >> PAGE_SHIFT;
<------>nr_align = 1UL << find_first_bit(&nr_pfns, BITS_PER_LONG);
<------>nr_align = ALIGN(pfn, nr_align) - pfn;
<------>if (nr_pfns + nr_align > vmem_altmap_nr_free(altmap))
<------><------>return NULL;
 
<------>altmap->alloc += nr_pfns;
<------>altmap->align += nr_align;
<------>pfn += nr_align;
 
<------>pr_debug("%s: pfn: %#lx alloc: %ld align: %ld nr: %#lx\n",
<------><------><------>__func__, pfn, altmap->alloc, altmap->align, nr_pfns);
<------>return __va(__pfn_to_phys(pfn));
}
 
void __meminit vmemmap_verify(pte_t *pte, int node,
<------><------><------><------>unsigned long start, unsigned long end)
{
<------>unsigned long pfn = pte_pfn(*pte);
<------>int actual_node = early_pfn_to_nid(pfn);
 
<------>if (node_distance(actual_node, node) > LOCAL_DISTANCE)
<------><------>pr_warn("[%lx-%lx] potential offnode page_structs\n",
<------><------><------>start, end - 1);
}
 
pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
<------><------><------><------>       struct vmem_altmap *altmap)
{
<------>pte_t *pte = pte_offset_kernel(pmd, addr);
<------>if (pte_none(*pte)) {
<------><------>pte_t entry;
<------><------>void *p;
 
<------><------>p = vmemmap_alloc_block_buf(PAGE_SIZE, node, altmap);
<------><------>if (!p)
<------><------><------>return NULL;
<------><------>entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
<------><------>set_pte_at(&init_mm, addr, pte, entry);
<------>}
<------>return pte;
}
 
static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node)
{
<------>void *p = vmemmap_alloc_block(size, node);
 
<------>if (!p)
<------><------>return NULL;
<------>memset(p, 0, size);
 
<------>return p;
}
 
pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
{
<------>pmd_t *pmd = pmd_offset(pud, addr);
<------>if (pmd_none(*pmd)) {
<------><------>void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
<------><------>if (!p)
<------><------><------>return NULL;
<------><------>pmd_populate_kernel(&init_mm, pmd, p);
<------>}
<------>return pmd;
}
 
pud_t * __meminit vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node)
{
<------>pud_t *pud = pud_offset(p4d, addr);
<------>if (pud_none(*pud)) {
<------><------>void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
<------><------>if (!p)
<------><------><------>return NULL;
<------><------>pud_populate(&init_mm, pud, p);
<------>}
<------>return pud;
}
 
p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node)
{
<------>p4d_t *p4d = p4d_offset(pgd, addr);
<------>if (p4d_none(*p4d)) {
<------><------>void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
<------><------>if (!p)
<------><------><------>return NULL;
<------><------>p4d_populate(&init_mm, p4d, p);
<------>}
<------>return p4d;
}
 
pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
{
<------>pgd_t *pgd = pgd_offset_k(addr);
<------>if (pgd_none(*pgd)) {
<------><------>void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
<------><------>if (!p)
<------><------><------>return NULL;
<------><------>pgd_populate(&init_mm, pgd, p);
<------>}
<------>return pgd;
}
 
int __meminit vmemmap_populate_basepages(unsigned long start, unsigned long end,
<------><------><------><------><------> int node, struct vmem_altmap *altmap)
{
<------>unsigned long addr = start;
<------>pgd_t *pgd;
<------>p4d_t *p4d;
<------>pud_t *pud;
<------>pmd_t *pmd;
<------>pte_t *pte;
 
<------>for (; addr < end; addr += PAGE_SIZE) {
<------><------>pgd = vmemmap_pgd_populate(addr, node);
<------><------>if (!pgd)
<------><------><------>return -ENOMEM;
<------><------>p4d = vmemmap_p4d_populate(pgd, addr, node);
<------><------>if (!p4d)
<------><------><------>return -ENOMEM;
<------><------>pud = vmemmap_pud_populate(p4d, addr, node);
<------><------>if (!pud)
<------><------><------>return -ENOMEM;
<------><------>pmd = vmemmap_pmd_populate(pud, addr, node);
<------><------>if (!pmd)
<------><------><------>return -ENOMEM;
<------><------>pte = vmemmap_pte_populate(pmd, addr, node, altmap);
<------><------>if (!pte)
<------><------><------>return -ENOMEM;
<------><------>vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
<------>}
 
<------>return 0;
}
 
struct page * __meminit __populate_section_memmap(unsigned long pfn,
<------><------>unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
{
<------>unsigned long start = (unsigned long) pfn_to_page(pfn);
<------>unsigned long end = start + nr_pages * sizeof(struct page);
 
<------>if (WARN_ON_ONCE(!IS_ALIGNED(pfn, PAGES_PER_SUBSECTION) ||
<------><------>!IS_ALIGNED(nr_pages, PAGES_PER_SUBSECTION)))
<------><------>return NULL;
 
<------>if (vmemmap_populate(start, end, nid, altmap))
<------><------>return NULL;
 
<------>return pfn_to_page(pfn);
}