1 /* 2 * Copyright (C) 2012, 2017, Red Hat Inc. 3 * 4 * This allocator provides contiguous physical addresses with page 5 * granularity. 6 */ 7 8 #include "libcflat.h" 9 #include "asm/spinlock.h" 10 #include "asm/page.h" 11 #include "asm/io.h" 12 #include "alloc.h" 13 #include "alloc_phys.h" 14 #include "alloc_page.h" 15 #include "vmalloc.h" 16 17 static struct spinlock lock; 18 static void *vfree_top = 0; 19 static void *page_root; 20 21 void *alloc_vpages(ulong nr) 22 { 23 spin_lock(&lock); 24 vfree_top -= PAGE_SIZE * nr; 25 spin_unlock(&lock); 26 return vfree_top; 27 } 28 29 void *alloc_vpage(void) 30 { 31 return alloc_vpages(1); 32 } 33 34 void init_alloc_vpage(void *top) 35 { 36 vfree_top = top; 37 } 38 39 void *vmap(phys_addr_t phys, size_t size) 40 { 41 void *mem, *p; 42 unsigned pages; 43 44 size = (size + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1); 45 pages = size / PAGE_SIZE; 46 mem = p = alloc_vpages(pages); 47 48 phys &= ~(unsigned long long)(PAGE_SIZE - 1); 49 while (pages--) { 50 install_page(page_root, phys, p); 51 phys += PAGE_SIZE; 52 p += PAGE_SIZE; 53 } 54 return mem; 55 } 56 57 static void *vm_memalign(size_t alignment, size_t size) 58 { 59 void *mem, *p; 60 unsigned pages; 61 62 assert(alignment <= PAGE_SIZE); 63 size = (size + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1); 64 pages = size / PAGE_SIZE; 65 mem = p = alloc_vpages(pages); 66 while (pages--) { 67 phys_addr_t pa = virt_to_phys(alloc_page()); 68 install_page(page_root, pa, p); 69 p += PAGE_SIZE; 70 } 71 return mem; 72 } 73 74 static void vm_free(void *mem, size_t size) 75 { 76 while (size) { 77 free_page(phys_to_virt(virt_to_pte_phys(page_root, mem))); 78 mem += PAGE_SIZE; 79 size -= PAGE_SIZE; 80 } 81 } 82 83 static struct alloc_ops vmalloc_ops = { 84 .memalign = vm_memalign, 85 .free = vm_free, 86 .align_min = PAGE_SIZE, 87 }; 88 89 void setup_vm() 90 { 91 phys_addr_t base, top; 92 93 if (alloc_ops == &vmalloc_ops) 94 return; 95 96 phys_alloc_get_unused(&base, &top); 97 base = (base + PAGE_SIZE - 1) & -PAGE_SIZE; 98 top = top & -PAGE_SIZE; 99 free_pages(phys_to_virt(base), top - base); 100 page_root = setup_mmu(top); 101 alloc_ops = &vmalloc_ops; 102 } 103