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![Anshuman Khandual](/assets/img/avatar_default.png)
There are many instances where vmemap allocation is often switched between regular memory and device memory just based on whether altmap is available or not. vmemmap_alloc_block_buf() is used in various platforms to allocate vmemmap mappings. Lets also enable it to handle altmap based device memory allocation along with existing regular memory allocations. This will help in avoiding the altmap based allocation switch in many places. To summarize there are two different methods to call vmemmap_alloc_block_buf(). vmemmap_alloc_block_buf(size, node, NULL) /* Allocate from system RAM */ vmemmap_alloc_block_buf(size, node, altmap) /* Allocate from altmap */ This converts altmap_alloc_block_buf() into a static function, drops it's entry from the header and updates Documentation/vm/memory-model.rst. Suggested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Jia He <justin.he@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Will Deacon <will@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Hsin-Yi Wang <hsinyi@chromium.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Steve Capper <steve.capper@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Yu Zhao <yuzhao@google.com> Link: http://lkml.kernel.org/r/1594004178-8861-3-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
273 lines
7 KiB
C
273 lines
7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Virtual Memory Map support
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*
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* (C) 2007 sgi. Christoph Lameter.
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*
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* Virtual memory maps allow VM primitives pfn_to_page, page_to_pfn,
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* virt_to_page, page_address() to be implemented as a base offset
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* calculation without memory access.
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*
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* However, virtual mappings need a page table and TLBs. Many Linux
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* architectures already map their physical space using 1-1 mappings
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* via TLBs. For those arches the virtual memory map is essentially
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* for free if we use the same page size as the 1-1 mappings. In that
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* case the overhead consists of a few additional pages that are
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* allocated to create a view of memory for vmemmap.
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*
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* The architecture is expected to provide a vmemmap_populate() function
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* to instantiate the mapping.
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*/
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#include <linux/mm.h>
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#include <linux/mmzone.h>
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#include <linux/memblock.h>
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#include <linux/memremap.h>
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#include <linux/highmem.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/vmalloc.h>
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#include <linux/sched.h>
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#include <asm/dma.h>
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#include <asm/pgalloc.h>
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/*
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* Allocate a block of memory to be used to back the virtual memory map
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* or to back the page tables that are used to create the mapping.
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* Uses the main allocators if they are available, else bootmem.
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*/
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static void * __ref __earlyonly_bootmem_alloc(int node,
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unsigned long size,
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unsigned long align,
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unsigned long goal)
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{
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return memblock_alloc_try_nid_raw(size, align, goal,
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MEMBLOCK_ALLOC_ACCESSIBLE, node);
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}
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void * __meminit vmemmap_alloc_block(unsigned long size, int node)
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{
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/* If the main allocator is up use that, fallback to bootmem. */
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if (slab_is_available()) {
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gfp_t gfp_mask = GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_NOWARN;
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int order = get_order(size);
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static bool warned;
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struct page *page;
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page = alloc_pages_node(node, gfp_mask, order);
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if (page)
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return page_address(page);
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if (!warned) {
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warn_alloc(gfp_mask & ~__GFP_NOWARN, NULL,
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"vmemmap alloc failure: order:%u", order);
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warned = true;
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}
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return NULL;
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} else
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return __earlyonly_bootmem_alloc(node, size, size,
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__pa(MAX_DMA_ADDRESS));
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}
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static void * __meminit altmap_alloc_block_buf(unsigned long size,
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struct vmem_altmap *altmap);
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/* need to make sure size is all the same during early stage */
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void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node,
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struct vmem_altmap *altmap)
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{
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void *ptr;
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if (altmap)
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return altmap_alloc_block_buf(size, altmap);
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ptr = sparse_buffer_alloc(size);
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if (!ptr)
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ptr = vmemmap_alloc_block(size, node);
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return ptr;
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}
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static unsigned long __meminit vmem_altmap_next_pfn(struct vmem_altmap *altmap)
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{
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return altmap->base_pfn + altmap->reserve + altmap->alloc
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+ altmap->align;
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}
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static unsigned long __meminit vmem_altmap_nr_free(struct vmem_altmap *altmap)
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{
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unsigned long allocated = altmap->alloc + altmap->align;
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if (altmap->free > allocated)
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return altmap->free - allocated;
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return 0;
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}
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static void * __meminit altmap_alloc_block_buf(unsigned long size,
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struct vmem_altmap *altmap)
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{
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unsigned long pfn, nr_pfns, nr_align;
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if (size & ~PAGE_MASK) {
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pr_warn_once("%s: allocations must be multiple of PAGE_SIZE (%ld)\n",
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__func__, size);
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return NULL;
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}
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pfn = vmem_altmap_next_pfn(altmap);
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nr_pfns = size >> PAGE_SHIFT;
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nr_align = 1UL << find_first_bit(&nr_pfns, BITS_PER_LONG);
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nr_align = ALIGN(pfn, nr_align) - pfn;
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if (nr_pfns + nr_align > vmem_altmap_nr_free(altmap))
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return NULL;
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altmap->alloc += nr_pfns;
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altmap->align += nr_align;
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pfn += nr_align;
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pr_debug("%s: pfn: %#lx alloc: %ld align: %ld nr: %#lx\n",
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__func__, pfn, altmap->alloc, altmap->align, nr_pfns);
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return __va(__pfn_to_phys(pfn));
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}
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void __meminit vmemmap_verify(pte_t *pte, int node,
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unsigned long start, unsigned long end)
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{
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unsigned long pfn = pte_pfn(*pte);
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int actual_node = early_pfn_to_nid(pfn);
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if (node_distance(actual_node, node) > LOCAL_DISTANCE)
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pr_warn("[%lx-%lx] potential offnode page_structs\n",
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start, end - 1);
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}
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pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
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struct vmem_altmap *altmap)
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{
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pte_t *pte = pte_offset_kernel(pmd, addr);
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if (pte_none(*pte)) {
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pte_t entry;
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void *p;
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p = vmemmap_alloc_block_buf(PAGE_SIZE, node, altmap);
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if (!p)
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return NULL;
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entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
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set_pte_at(&init_mm, addr, pte, entry);
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}
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return pte;
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}
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static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node)
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{
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void *p = vmemmap_alloc_block(size, node);
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if (!p)
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return NULL;
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memset(p, 0, size);
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return p;
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}
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pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
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{
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pmd_t *pmd = pmd_offset(pud, addr);
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if (pmd_none(*pmd)) {
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void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
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if (!p)
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return NULL;
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pmd_populate_kernel(&init_mm, pmd, p);
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}
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return pmd;
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}
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pud_t * __meminit vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node)
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{
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pud_t *pud = pud_offset(p4d, addr);
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if (pud_none(*pud)) {
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void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
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if (!p)
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return NULL;
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pud_populate(&init_mm, pud, p);
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}
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return pud;
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}
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p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node)
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{
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p4d_t *p4d = p4d_offset(pgd, addr);
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if (p4d_none(*p4d)) {
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void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
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if (!p)
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return NULL;
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p4d_populate(&init_mm, p4d, p);
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}
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return p4d;
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}
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pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
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{
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pgd_t *pgd = pgd_offset_k(addr);
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if (pgd_none(*pgd)) {
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void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
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if (!p)
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return NULL;
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pgd_populate(&init_mm, pgd, p);
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}
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return pgd;
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}
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int __meminit vmemmap_populate_basepages(unsigned long start, unsigned long end,
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int node, struct vmem_altmap *altmap)
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{
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unsigned long addr = start;
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pgd_t *pgd;
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p4d_t *p4d;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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for (; addr < end; addr += PAGE_SIZE) {
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pgd = vmemmap_pgd_populate(addr, node);
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if (!pgd)
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return -ENOMEM;
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p4d = vmemmap_p4d_populate(pgd, addr, node);
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if (!p4d)
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return -ENOMEM;
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pud = vmemmap_pud_populate(p4d, addr, node);
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if (!pud)
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return -ENOMEM;
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pmd = vmemmap_pmd_populate(pud, addr, node);
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if (!pmd)
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return -ENOMEM;
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pte = vmemmap_pte_populate(pmd, addr, node, altmap);
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if (!pte)
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return -ENOMEM;
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vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
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}
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return 0;
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}
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struct page * __meminit __populate_section_memmap(unsigned long pfn,
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unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
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{
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unsigned long start;
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unsigned long end;
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/*
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* The minimum granularity of memmap extensions is
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* PAGES_PER_SUBSECTION as allocations are tracked in the
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* 'subsection_map' bitmap of the section.
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*/
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end = ALIGN(pfn + nr_pages, PAGES_PER_SUBSECTION);
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pfn &= PAGE_SUBSECTION_MASK;
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nr_pages = end - pfn;
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start = (unsigned long) pfn_to_page(pfn);
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end = start + nr_pages * sizeof(struct page);
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if (vmemmap_populate(start, end, nid, altmap))
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return NULL;
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return pfn_to_page(pfn);
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}
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