1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/sched.h> 3 #include <linux/kernel.h> 4 #include <linux/errno.h> 5 #include <linux/mm.h> 6 #include <linux/nmi.h> 7 #include <linux/swap.h> 8 #include <linux/smp.h> 9 #include <linux/highmem.h> 10 #include <linux/pagemap.h> 11 #include <linux/spinlock.h> 12 13 #include <asm/cpu_entry_area.h> 14 #include <asm/pgtable.h> 15 #include <asm/pgalloc.h> 16 #include <asm/fixmap.h> 17 #include <asm/e820/api.h> 18 #include <asm/tlb.h> 19 #include <asm/tlbflush.h> 20 #include <asm/io.h> 21 22 unsigned int __VMALLOC_RESERVE = 128 << 20; 23 24 /* 25 * Associate a virtual page frame with a given physical page frame 26 * and protection flags for that frame. 27 */ 28 void set_pte_vaddr(unsigned long vaddr, pte_t pteval) 29 { 30 pgd_t *pgd; 31 p4d_t *p4d; 32 pud_t *pud; 33 pmd_t *pmd; 34 pte_t *pte; 35 36 pgd = swapper_pg_dir + pgd_index(vaddr); 37 if (pgd_none(*pgd)) { 38 BUG(); 39 return; 40 } 41 p4d = p4d_offset(pgd, vaddr); 42 if (p4d_none(*p4d)) { 43 BUG(); 44 return; 45 } 46 pud = pud_offset(p4d, vaddr); 47 if (pud_none(*pud)) { 48 BUG(); 49 return; 50 } 51 pmd = pmd_offset(pud, vaddr); 52 if (pmd_none(*pmd)) { 53 BUG(); 54 return; 55 } 56 pte = pte_offset_kernel(pmd, vaddr); 57 if (!pte_none(pteval)) 58 set_pte_at(&init_mm, vaddr, pte, pteval); 59 else 60 pte_clear(&init_mm, vaddr, pte); 61 62 /* 63 * It's enough to flush this one mapping. 64 * (PGE mappings get flushed as well) 65 */ 66 __flush_tlb_one_kernel(vaddr); 67 } 68 69 unsigned long __FIXADDR_TOP = 0xfffff000; 70 EXPORT_SYMBOL(__FIXADDR_TOP); 71 72 /* 73 * vmalloc=size forces the vmalloc area to be exactly 'size' 74 * bytes. This can be used to increase (or decrease) the 75 * vmalloc area - the default is 128m. 76 */ 77 static int __init parse_vmalloc(char *arg) 78 { 79 if (!arg) 80 return -EINVAL; 81 82 /* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/ 83 __VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET; 84 return 0; 85 } 86 early_param("vmalloc", parse_vmalloc); 87 88 /* 89 * reservetop=size reserves a hole at the top of the kernel address space which 90 * a hypervisor can load into later. Needed for dynamically loaded hypervisors, 91 * so relocating the fixmap can be done before paging initialization. 92 */ 93 static int __init parse_reservetop(char *arg) 94 { 95 unsigned long address; 96 97 if (!arg) 98 return -EINVAL; 99 100 address = memparse(arg, &arg); 101 reserve_top_address(address); 102 early_ioremap_init(); 103 return 0; 104 } 105 early_param("reservetop", parse_reservetop); 106