/* 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 */