1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_PAGE_64_H 3 #define _ASM_X86_PAGE_64_H 4 5 #include <asm/page_64_types.h> 6 7 #ifndef __ASSEMBLY__ 8 #include <asm/alternative.h> 9 10 /* duplicated to the one in bootmem.h */ 11 extern unsigned long max_pfn; 12 extern unsigned long phys_base; 13 14 extern unsigned long page_offset_base; 15 extern unsigned long vmalloc_base; 16 extern unsigned long vmemmap_base; 17 18 static inline unsigned long __phys_addr_nodebug(unsigned long x) 19 { 20 unsigned long y = x - __START_KERNEL_map; 21 22 /* use the carry flag to determine if x was < __START_KERNEL_map */ 23 x = y + ((x > y) ? phys_base : (__START_KERNEL_map - PAGE_OFFSET)); 24 25 return x; 26 } 27 28 #ifdef CONFIG_DEBUG_VIRTUAL 29 extern unsigned long __phys_addr(unsigned long); 30 extern unsigned long __phys_addr_symbol(unsigned long); 31 #else 32 #define __phys_addr(x) __phys_addr_nodebug(x) 33 #define __phys_addr_symbol(x) \ 34 ((unsigned long)(x) - __START_KERNEL_map + phys_base) 35 #endif 36 37 #define __phys_reloc_hide(x) (x) 38 39 #ifdef CONFIG_FLATMEM 40 #define pfn_valid(pfn) ((pfn) < max_pfn) 41 #endif 42 43 void clear_page_orig(void *page); 44 void clear_page_rep(void *page); 45 void clear_page_erms(void *page); 46 47 static inline void clear_page(void *page) 48 { 49 alternative_call_2(clear_page_orig, 50 clear_page_rep, X86_FEATURE_REP_GOOD, 51 clear_page_erms, X86_FEATURE_ERMS, 52 "=D" (page), 53 "0" (page) 54 : "cc", "memory", "rax", "rcx"); 55 } 56 57 void copy_page(void *to, void *from); 58 59 #ifdef CONFIG_X86_5LEVEL 60 /* 61 * User space process size. This is the first address outside the user range. 62 * There are a few constraints that determine this: 63 * 64 * On Intel CPUs, if a SYSCALL instruction is at the highest canonical 65 * address, then that syscall will enter the kernel with a 66 * non-canonical return address, and SYSRET will explode dangerously. 67 * We avoid this particular problem by preventing anything 68 * from being mapped at the maximum canonical address. 69 * 70 * On AMD CPUs in the Ryzen family, there's a nasty bug in which the 71 * CPUs malfunction if they execute code from the highest canonical page. 72 * They'll speculate right off the end of the canonical space, and 73 * bad things happen. This is worked around in the same way as the 74 * Intel problem. 75 * 76 * With page table isolation enabled, we map the LDT in ... [stay tuned] 77 */ 78 static inline unsigned long task_size_max(void) 79 { 80 unsigned long ret; 81 82 alternative_io("movq %[small],%0","movq %[large],%0", 83 X86_FEATURE_LA57, 84 "=r" (ret), 85 [small] "i" ((1ul << 47)-PAGE_SIZE), 86 [large] "i" ((1ul << 56)-PAGE_SIZE)); 87 88 return ret; 89 } 90 #endif /* CONFIG_X86_5LEVEL */ 91 92 #endif /* !__ASSEMBLY__ */ 93 94 #ifdef CONFIG_X86_VSYSCALL_EMULATION 95 # define __HAVE_ARCH_GATE_AREA 1 96 #endif 97 98 #endif /* _ASM_X86_PAGE_64_H */ 99