diff options
Diffstat (limited to 'arch/powerpc/include/asm/page.h')
| -rw-r--r-- | arch/powerpc/include/asm/page.h | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h new file mode 100644 index 000000000..e5fcc79b5 --- /dev/null +++ b/arch/powerpc/include/asm/page.h @@ -0,0 +1,335 @@ +/* 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 __ASSEMBLY__ +#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. + */ +#define PAGE_SHIFT CONFIG_PPC_PAGE_SHIFT +#define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT) + +#ifndef __ASSEMBLY__ +#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 + +/* + * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we + * assign PAGE_MASK to a larger type it gets extended the way we want + * (i.e. with 1s in the high bits) + */ +#define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) + +/* + * 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 __ASSEMBLY__ + +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 /* __ASSEMBLY__ */ +#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 __ASSEMBLY__ +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 CONFIG_PPC_BOOK3S_64 +/* + * Use the top bit of the higher-level page table entries to indicate whether + * the entries we point to contain hugepages. This works because we know that + * the page tables live in kernel space. If we ever decide to support having + * page tables at arbitrary addresses, this breaks and will have to change. + */ +#ifdef CONFIG_PPC64 +#define PD_HUGE 0x8000000000000000UL +#else +#define PD_HUGE 0x80000000 +#endif + +#else /* CONFIG_PPC_BOOK3S_64 */ +/* + * Book3S 64 stores real addresses in the hugepd entries to + * avoid overlaps with _PAGE_PRESENT and _PAGE_PTE. + */ +#define HUGEPD_ADDR_MASK (0x0ffffffffffffffful & ~HUGEPD_SHIFT_MASK) +#endif /* CONFIG_PPC_BOOK3S_64 */ + +/* + * Some number of bits at the level of the page table that points to + * a hugepte are used to encode the size. This masks those bits. + * On 8xx, HW assistance requires 4k alignment for the hugepte. + */ +#ifdef CONFIG_PPC_8xx +#define HUGEPD_SHIFT_MASK 0xfff +#else +#define HUGEPD_SHIFT_MASK 0x3f +#endif + +#ifndef __ASSEMBLY__ + +#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); +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 /* __ASSEMBLY__ */ + +#endif /* _ASM_POWERPC_PAGE_H */ |