/* SPDX-License-Identifier: GPL-2.0-or-later */ #ifndef _ASM_POWERPC_PAGE_H #define _ASM_POWERPC_PAGE_H /* * Copyright (C) 2001,2005 IBM Corporation. */ #ifndef __ASSEMBLER__ #include <linux/types.h> #include <linux/kernel.h> #include <linux/bug.h> #else #include <asm/types.h> #endif #include <asm/asm-const.h> /* * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages * on PPC44x and 4K/16K on 8xx). For PPC64 we support either 4K or 64K software * page size. When using 64K pages however, whether we are really supporting * 64K pages in HW or not is irrelevant to those definitions. */ #include <vdso/page.h> #ifndef __ASSEMBLER__ #ifndef CONFIG_HUGETLB_PAGE #define HPAGE_SHIFT PAGE_SHIFT #elif defined(CONFIG_PPC_BOOK3S_64) extern unsigned int hpage_shift; #define HPAGE_SHIFT hpage_shift #elif defined(CONFIG_PPC_8xx) #define HPAGE_SHIFT 19 /* 512k pages */ #elif defined(CONFIG_PPC_E500) #define HPAGE_SHIFT 22 /* 4M pages */ #endif #define HPAGE_SIZE ((1UL) << HPAGE_SHIFT) #define HPAGE_MASK (~(HPAGE_SIZE - 1)) #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT) #define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1) #endif /* * KERNELBASE is the virtual address of the start of the kernel, it's often * the same as PAGE_OFFSET, but _might not be_. * * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET. * * PAGE_OFFSET is the virtual address of the start of lowmem. * * PHYSICAL_START is the physical address of the start of the kernel. * * MEMORY_START is the physical address of the start of lowmem. * * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on * ppc32 and based on how they are set we determine MEMORY_START. * * For the linear mapping the following equation should be true: * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START * * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START * * There are two ways to determine a physical address from a virtual one: * va = pa + PAGE_OFFSET - MEMORY_START * va = pa + KERNELBASE - PHYSICAL_START * * If you want to know something's offset from the start of the kernel you * should subtract KERNELBASE. * * If you want to test if something's a kernel address, use is_kernel_addr(). */ #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START) #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET) #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START)) #if defined(CONFIG_NONSTATIC_KERNEL) #ifndef __ASSEMBLER__ extern phys_addr_t memstart_addr; extern phys_addr_t kernstart_addr; #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC32) extern long long virt_phys_offset; #endif #endif /* __ASSEMBLER__ */ #define PHYSICAL_START kernstart_addr #else /* !CONFIG_NONSTATIC_KERNEL */ #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START) #endif /* See Description below for VIRT_PHYS_OFFSET */ #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) #ifdef CONFIG_RELOCATABLE #define VIRT_PHYS_OFFSET virt_phys_offset #else #define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START) #endif #endif #ifdef CONFIG_PPC64 #define MEMORY_START 0UL #elif defined(CONFIG_NONSTATIC_KERNEL) #define MEMORY_START memstart_addr #else #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE) #endif #ifdef CONFIG_FLATMEM #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT)) #endif /* * On Book-E parts we need __va to parse the device tree and we can't * determine MEMORY_START until then. However we can determine PHYSICAL_START * from information at hand (program counter, TLB lookup). * * On BookE with RELOCATABLE && PPC32 * * With RELOCATABLE && PPC32, we support loading the kernel at any physical * address without any restriction on the page alignment. * * We find the runtime address of _stext and relocate ourselves based on * the following calculation: * * virtual_base = ALIGN_DOWN(KERNELBASE,256M) + * MODULO(_stext.run,256M) * and create the following mapping: * * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M) * * When we process relocations, we cannot depend on the * existing equation for the __va()/__pa() translations: * * __va(x) = (x) - PHYSICAL_START + KERNELBASE * * Where: * PHYSICAL_START = kernstart_addr = Physical address of _stext * KERNELBASE = Compiled virtual address of _stext. * * This formula holds true iff, kernel load address is TLB page aligned. * * In our case, we need to also account for the shift in the kernel Virtual * address. * * E.g., * * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET). * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M * * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000 * = 0xbc100000 , which is wrong. * * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000 * according to our mapping. * * Hence we use the following formula to get the translations right: * * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ] * * Where : * PHYSICAL_START = dynamic load address.(kernstart_addr variable) * Effective KERNELBASE = virtual_base = * = ALIGN_DOWN(KERNELBASE,256M) + * MODULO(PHYSICAL_START,256M) * * To make the cost of __va() / __pa() more light weight, we introduce * a new variable virt_phys_offset, which will hold : * * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START * = ALIGN_DOWN(KERNELBASE,256M) - * ALIGN_DOWN(PHYSICALSTART,256M) * * Hence : * * __va(x) = x - PHYSICAL_START + Effective KERNELBASE * = x + virt_phys_offset * * and * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE * = x - virt_phys_offset * * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use * the other definitions for __va & __pa. */ #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET)) #define __pa(x) ((phys_addr_t)(unsigned long)(x) - VIRT_PHYS_OFFSET) #else #ifdef CONFIG_PPC64 #define VIRTUAL_WARN_ON(x) WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && (x)) /* * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit. * This also results in better code generation. */ #define __va(x) \ ({ \ VIRTUAL_WARN_ON((unsigned long)(x) >= PAGE_OFFSET); \ (void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET); \ }) #define __pa(x) \ ({ \ VIRTUAL_WARN_ON((unsigned long)(x) < PAGE_OFFSET); \ (unsigned long)(x) & 0x0fffffffffffffffUL; \ }) #else /* 32-bit, non book E */ #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START)) #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START) #endif #endif #ifndef __ASSEMBLER__ static inline unsigned long virt_to_pfn(const void *kaddr) { return __pa(kaddr) >> PAGE_SHIFT; } static inline const void *pfn_to_kaddr(unsigned long pfn) { return __va(pfn << PAGE_SHIFT); } #endif #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr)) #define virt_addr_valid(vaddr) ({ \ unsigned long _addr = (unsigned long)vaddr; \ _addr >= PAGE_OFFSET && _addr < (unsigned long)high_memory && \ pfn_valid(virt_to_pfn((void *)_addr)); \ }) /* * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI, * and needs to be executable. This means the whole heap ends * up being executable. */ #define VM_DATA_DEFAULT_FLAGS32 VM_DATA_FLAGS_TSK_EXEC #define VM_DATA_DEFAULT_FLAGS64 VM_DATA_FLAGS_NON_EXEC #ifdef __powerpc64__ #include <asm/page_64.h> #else #include <asm/page_32.h> #endif /* * Don't compare things with KERNELBASE or PAGE_OFFSET to test for * "kernelness", use is_kernel_addr() - it should do what you want. */ #ifdef CONFIG_PPC_BOOK3E_64 #define is_kernel_addr(x) ((x) >= 0x8000000000000000ul) #elif defined(CONFIG_PPC_BOOK3S_64) #define is_kernel_addr(x) ((x) >= PAGE_OFFSET) #else #define is_kernel_addr(x) ((x) >= TASK_SIZE) #endif #ifndef __ASSEMBLER__ #ifdef CONFIG_PPC_BOOK3S_64 #include <asm/pgtable-be-types.h> #else #include <asm/pgtable-types.h> #endif struct page; extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg); #define clear_user_page clear_user_page extern void copy_user_page(void *to, void *from, unsigned long vaddr, struct page *p); extern int devmem_is_allowed(unsigned long pfn); #ifdef CONFIG_PPC_SMLPAR void arch_free_page(struct page *page, int order); #define HAVE_ARCH_FREE_PAGE #endif struct vm_area_struct; extern unsigned long kernstart_virt_addr; static inline unsigned long kaslr_offset(void) { return kernstart_virt_addr - KERNELBASE; } #include <asm-generic/memory_model.h> #endif /* __ASSEMBLER__ */ #endif /* _ASM_POWERPC_PAGE_H */
