linux/arch/parisc/include/asm/page.h
John David Anglin 2de8b4cc20 parisc: Rewrite cache flush code for PA8800/PA8900
Originally, I was convinced that we needed to use tmpalias flushes
everwhere, for both user and kernel flushes. However, when I modified
flush_kernel_dcache_page_addr, to use a tmpalias flush, my c8000
would crash quite early when booting.

The PDC returns alias values of 0 for the icache and dcache. This
indicates that either the alias boundary is greater than 16MB or
equivalent aliasing doesn't work. I modified the tmpalias code to
make it easy to try alternate boundaries. I tried boundaries up to
128MB but still kernel tmpalias flushes didn't work on c8000.

This led me to conclude that tmpalias flushes don't work on PA8800
and PA8900 machines, and that we needed to flush directly using the
virtual address of user and kernel pages. This is likely the major
cause of instability on the c8000 and rp34xx machines.

Flushing user pages requires doing a temporary context switch as we
have to flush pages that don't belong to the current context. Further,
we have to deal with pages that aren't present. If a page isn't
present, the flush instructions fault on every line.

Other code has been rearranged and simplified based on testing. For
example, I introduced a flush_cache_dup_mm routine. flush_cache_mm
and flush_cache_dup_mm differ in that flush_cache_mm calls
purge_cache_pages and flush_cache_dup_mm calls flush_cache_pages.
In some implementations, pdc is more efficient than fdc. Based on
my testing, I don't believe there's any performance benefit on the
c8000.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
2022-05-17 21:52:47 +02:00

195 lines
5.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _PARISC_PAGE_H
#define _PARISC_PAGE_H
#include <linux/const.h>
#if defined(CONFIG_PARISC_PAGE_SIZE_4KB)
# define PAGE_SHIFT 12
#elif defined(CONFIG_PARISC_PAGE_SIZE_16KB)
# define PAGE_SHIFT 14
#elif defined(CONFIG_PARISC_PAGE_SIZE_64KB)
# define PAGE_SHIFT 16
#else
# error "unknown default kernel page size"
#endif
#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
#ifndef __ASSEMBLY__
#include <asm/types.h>
#include <asm/cache.h>
#define clear_page(page) clear_page_asm((void *)(page))
#define copy_page(to, from) copy_page_asm((void *)(to), (void *)(from))
struct page;
struct vm_area_struct;
void clear_page_asm(void *page);
void copy_page_asm(void *to, void *from);
#define clear_user_page(vto, vaddr, page) clear_page_asm(vto)
void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr,
struct vm_area_struct *vma);
#define __HAVE_ARCH_COPY_USER_HIGHPAGE
/*
* These are used to make use of C type-checking..
*/
#define STRICT_MM_TYPECHECKS
#ifdef STRICT_MM_TYPECHECKS
typedef struct { unsigned long pte; } pte_t; /* either 32 or 64bit */
/* NOTE: even on 64 bits, these entries are __u32 because we allocate
* the pmd and pgd in ZONE_DMA (i.e. under 4GB) */
typedef struct { __u32 pgd; } pgd_t;
typedef struct { unsigned long pgprot; } pgprot_t;
#if CONFIG_PGTABLE_LEVELS == 3
typedef struct { __u32 pmd; } pmd_t;
#define __pmd(x) ((pmd_t) { (x) } )
/* pXd_val() do not work as lvalues, so make sure we don't use them as such. */
#define pmd_val(x) ((x).pmd + 0)
#endif
#define pte_val(x) ((x).pte)
#define pgd_val(x) ((x).pgd + 0)
#define pgprot_val(x) ((x).pgprot)
#define __pte(x) ((pte_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )
#else
/*
* .. while these make it easier on the compiler
*/
typedef unsigned long pte_t;
#if CONFIG_PGTABLE_LEVELS == 3
typedef __u32 pmd_t;
#define pmd_val(x) (x)
#define __pmd(x) (x)
#endif
typedef __u32 pgd_t;
typedef unsigned long pgprot_t;
#define pte_val(x) (x)
#define pgd_val(x) (x)
#define pgprot_val(x) (x)
#define __pte(x) (x)
#define __pgd(x) (x)
#define __pgprot(x) (x)
#endif /* STRICT_MM_TYPECHECKS */
#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
#if CONFIG_PGTABLE_LEVELS == 3
#define set_pud(pudptr, pudval) (*(pudptr) = (pudval))
#endif
typedef struct page *pgtable_t;
typedef struct __physmem_range {
unsigned long start_pfn;
unsigned long pages; /* PAGE_SIZE pages */
} physmem_range_t;
extern physmem_range_t pmem_ranges[];
extern int npmem_ranges;
#endif /* !__ASSEMBLY__ */
/* WARNING: The definitions below must match exactly to sizeof(pte_t)
* etc
*/
#ifdef CONFIG_64BIT
#define BITS_PER_PTE_ENTRY 3
#define BITS_PER_PMD_ENTRY 2
#define BITS_PER_PGD_ENTRY 2
#else
#define BITS_PER_PTE_ENTRY 2
#define BITS_PER_PMD_ENTRY 2
#define BITS_PER_PGD_ENTRY 2
#endif
#define PGD_ENTRY_SIZE (1UL << BITS_PER_PGD_ENTRY)
#define PMD_ENTRY_SIZE (1UL << BITS_PER_PMD_ENTRY)
#define PTE_ENTRY_SIZE (1UL << BITS_PER_PTE_ENTRY)
#define LINUX_GATEWAY_SPACE 0
/* This governs the relationship between virtual and physical addresses.
* If you alter it, make sure to take care of our various fixed mapping
* segments in fixmap.h */
#ifdef CONFIG_64BIT
#define __PAGE_OFFSET_DEFAULT (0x40000000) /* 1GB */
#else
#define __PAGE_OFFSET_DEFAULT (0x10000000) /* 256MB */
#endif
#if defined(BOOTLOADER)
#define __PAGE_OFFSET (0) /* bootloader uses physical addresses */
#else
#define __PAGE_OFFSET __PAGE_OFFSET_DEFAULT
#endif /* BOOTLOADER */
#define PAGE_OFFSET ((unsigned long)__PAGE_OFFSET)
/* The size of the gateway page (we leave lots of room for expansion) */
#define GATEWAY_PAGE_SIZE 0x4000
/* The start of the actual kernel binary---used in vmlinux.lds.S
* Leave some space after __PAGE_OFFSET for detecting kernel null
* ptr derefs */
#define KERNEL_BINARY_TEXT_START (__PAGE_OFFSET + 0x100000)
/* These macros don't work for 64-bit C code -- don't allow in C at all */
#ifdef __ASSEMBLY__
# define PA(x) ((x)-__PAGE_OFFSET)
# define VA(x) ((x)+__PAGE_OFFSET)
#endif
#define __pa(x) ((unsigned long)(x)-PAGE_OFFSET)
#define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET))
#ifndef CONFIG_SPARSEMEM
#define pfn_valid(pfn) ((pfn) < max_mapnr)
#endif
#ifdef CONFIG_HUGETLB_PAGE
#define HPAGE_SHIFT PMD_SHIFT /* fixed for transparent huge pages */
#define HPAGE_SIZE ((1UL) << HPAGE_SHIFT)
#define HPAGE_MASK (~(HPAGE_SIZE - 1))
#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
#if defined(CONFIG_64BIT) && defined(CONFIG_PARISC_PAGE_SIZE_4KB)
# define REAL_HPAGE_SHIFT 20 /* 20 = 1MB */
# define _HUGE_PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_1M
#elif !defined(CONFIG_64BIT) && defined(CONFIG_PARISC_PAGE_SIZE_4KB)
# define REAL_HPAGE_SHIFT 22 /* 22 = 4MB */
# define _HUGE_PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_4M
#else
# define REAL_HPAGE_SHIFT 24 /* 24 = 16MB */
# define _HUGE_PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_16M
#endif
#endif /* CONFIG_HUGETLB_PAGE */
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#include <asm-generic/memory_model.h>
#include <asm-generic/getorder.h>
#include <asm/pdc.h>
#define PAGE0 ((struct zeropage *)absolute_pointer(__PAGE_OFFSET))
/* DEFINITION OF THE ZERO-PAGE (PAG0) */
/* based on work by Jason Eckhardt (jason@equator.com) */
#endif /* _PARISC_PAGE_H */