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Diffstat (limited to 'arch/m68k/mm/memory.c')
| -rw-r--r-- | arch/m68k/mm/memory.c | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/arch/m68k/mm/memory.c b/arch/m68k/mm/memory.c new file mode 100644 index 000000000..b86a2e216 --- /dev/null +++ b/arch/m68k/mm/memory.c @@ -0,0 +1,297 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/arch/m68k/mm/memory.c + * + * Copyright (C) 1995 Hamish Macdonald + */ + +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/init.h> +#include <linux/pagemap.h> +#include <linux/gfp.h> + +#include <asm/setup.h> +#include <asm/segment.h> +#include <asm/page.h> +#include <asm/pgalloc.h> +#include <asm/traps.h> +#include <asm/machdep.h> + + +/* ++andreas: {get,free}_pointer_table rewritten to use unused fields from + struct page instead of separately kmalloced struct. Stolen from + arch/sparc/mm/srmmu.c ... */ + +typedef struct list_head ptable_desc; +static LIST_HEAD(ptable_list); + +#define PD_PTABLE(page) ((ptable_desc *)&(virt_to_page(page)->lru)) +#define PD_PAGE(ptable) (list_entry(ptable, struct page, lru)) +#define PD_MARKBITS(dp) (*(unsigned char *)&PD_PAGE(dp)->index) + +#define PTABLE_SIZE (PTRS_PER_PMD * sizeof(pmd_t)) + +void __init init_pointer_table(unsigned long ptable) +{ + ptable_desc *dp; + unsigned long page = ptable & PAGE_MASK; + unsigned char mask = 1 << ((ptable - page)/PTABLE_SIZE); + + dp = PD_PTABLE(page); + if (!(PD_MARKBITS(dp) & mask)) { + PD_MARKBITS(dp) = 0xff; + list_add(dp, &ptable_list); + } + + PD_MARKBITS(dp) &= ~mask; + pr_debug("init_pointer_table: %lx, %x\n", ptable, PD_MARKBITS(dp)); + + /* unreserve the page so it's possible to free that page */ + PD_PAGE(dp)->flags &= ~(1 << PG_reserved); + init_page_count(PD_PAGE(dp)); + + return; +} + +pmd_t *get_pointer_table (void) +{ + ptable_desc *dp = ptable_list.next; + unsigned char mask = PD_MARKBITS (dp); + unsigned char tmp; + unsigned int off; + + /* + * For a pointer table for a user process address space, a + * table is taken from a page allocated for the purpose. Each + * page can hold 8 pointer tables. The page is remapped in + * virtual address space to be noncacheable. + */ + if (mask == 0) { + void *page; + ptable_desc *new; + + if (!(page = (void *)get_zeroed_page(GFP_KERNEL))) + return NULL; + + flush_tlb_kernel_page(page); + nocache_page(page); + + new = PD_PTABLE(page); + PD_MARKBITS(new) = 0xfe; + list_add_tail(new, dp); + + return (pmd_t *)page; + } + + for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += PTABLE_SIZE) + ; + PD_MARKBITS(dp) = mask & ~tmp; + if (!PD_MARKBITS(dp)) { + /* move to end of list */ + list_move_tail(dp, &ptable_list); + } + return (pmd_t *) (page_address(PD_PAGE(dp)) + off); +} + +int free_pointer_table (pmd_t *ptable) +{ + ptable_desc *dp; + unsigned long page = (unsigned long)ptable & PAGE_MASK; + unsigned char mask = 1 << (((unsigned long)ptable - page)/PTABLE_SIZE); + + dp = PD_PTABLE(page); + if (PD_MARKBITS (dp) & mask) + panic ("table already free!"); + + PD_MARKBITS (dp) |= mask; + + if (PD_MARKBITS(dp) == 0xff) { + /* all tables in page are free, free page */ + list_del(dp); + cache_page((void *)page); + free_page (page); + return 1; + } else if (ptable_list.next != dp) { + /* + * move this descriptor to the front of the list, since + * it has one or more free tables. + */ + list_move(dp, &ptable_list); + } + return 0; +} + +/* invalidate page in both caches */ +static inline void clear040(unsigned long paddr) +{ + asm volatile ( + "nop\n\t" + ".chip 68040\n\t" + "cinvp %%bc,(%0)\n\t" + ".chip 68k" + : : "a" (paddr)); +} + +/* invalidate page in i-cache */ +static inline void cleari040(unsigned long paddr) +{ + asm volatile ( + "nop\n\t" + ".chip 68040\n\t" + "cinvp %%ic,(%0)\n\t" + ".chip 68k" + : : "a" (paddr)); +} + +/* push page in both caches */ +/* RZ: cpush %bc DOES invalidate %ic, regardless of DPI */ +static inline void push040(unsigned long paddr) +{ + asm volatile ( + "nop\n\t" + ".chip 68040\n\t" + "cpushp %%bc,(%0)\n\t" + ".chip 68k" + : : "a" (paddr)); +} + +/* push and invalidate page in both caches, must disable ints + * to avoid invalidating valid data */ +static inline void pushcl040(unsigned long paddr) +{ + unsigned long flags; + + local_irq_save(flags); + push040(paddr); + if (CPU_IS_060) + clear040(paddr); + local_irq_restore(flags); +} + +/* + * 040: Hit every page containing an address in the range paddr..paddr+len-1. + * (Low order bits of the ea of a CINVP/CPUSHP are "don't care"s). + * Hit every page until there is a page or less to go. Hit the next page, + * and the one after that if the range hits it. + */ +/* ++roman: A little bit more care is required here: The CINVP instruction + * invalidates cache entries WITHOUT WRITING DIRTY DATA BACK! So the beginning + * and the end of the region must be treated differently if they are not + * exactly at the beginning or end of a page boundary. Else, maybe too much + * data becomes invalidated and thus lost forever. CPUSHP does what we need: + * it invalidates the page after pushing dirty data to memory. (Thanks to Jes + * for discovering the problem!) + */ +/* ... but on the '060, CPUSH doesn't invalidate (for us, since we have set + * the DPI bit in the CACR; would it cause problems with temporarily changing + * this?). So we have to push first and then additionally to invalidate. + */ + + +/* + * cache_clear() semantics: Clear any cache entries for the area in question, + * without writing back dirty entries first. This is useful if the data will + * be overwritten anyway, e.g. by DMA to memory. The range is defined by a + * _physical_ address. + */ + +void cache_clear (unsigned long paddr, int len) +{ + if (CPU_IS_COLDFIRE) { + clear_cf_bcache(0, DCACHE_MAX_ADDR); + } else if (CPU_IS_040_OR_060) { + int tmp; + + /* + * We need special treatment for the first page, in case it + * is not page-aligned. Page align the addresses to work + * around bug I17 in the 68060. + */ + if ((tmp = -paddr & (PAGE_SIZE - 1))) { + pushcl040(paddr & PAGE_MASK); + if ((len -= tmp) <= 0) + return; + paddr += tmp; + } + tmp = PAGE_SIZE; + paddr &= PAGE_MASK; + while ((len -= tmp) >= 0) { + clear040(paddr); + paddr += tmp; + } + if ((len += tmp)) + /* a page boundary gets crossed at the end */ + pushcl040(paddr); + } + else /* 68030 or 68020 */ + asm volatile ("movec %/cacr,%/d0\n\t" + "oriw %0,%/d0\n\t" + "movec %/d0,%/cacr" + : : "i" (FLUSH_I_AND_D) + : "d0"); +#ifdef CONFIG_M68K_L2_CACHE + if(mach_l2_flush) + mach_l2_flush(0); +#endif +} +EXPORT_SYMBOL(cache_clear); + + +/* + * cache_push() semantics: Write back any dirty cache data in the given area, + * and invalidate the range in the instruction cache. It needs not (but may) + * invalidate those entries also in the data cache. The range is defined by a + * _physical_ address. + */ + +void cache_push (unsigned long paddr, int len) +{ + if (CPU_IS_COLDFIRE) { + flush_cf_bcache(0, DCACHE_MAX_ADDR); + } else if (CPU_IS_040_OR_060) { + int tmp = PAGE_SIZE; + + /* + * on 68040 or 68060, push cache lines for pages in the range; + * on the '040 this also invalidates the pushed lines, but not on + * the '060! + */ + len += paddr & (PAGE_SIZE - 1); + + /* + * Work around bug I17 in the 68060 affecting some instruction + * lines not being invalidated properly. + */ + paddr &= PAGE_MASK; + + do { + push040(paddr); + paddr += tmp; + } while ((len -= tmp) > 0); + } + /* + * 68030/68020 have no writeback cache. On the other hand, + * cache_push is actually a superset of cache_clear (the lines + * get written back and invalidated), so we should make sure + * to perform the corresponding actions. After all, this is getting + * called in places where we've just loaded code, or whatever, so + * flushing the icache is appropriate; flushing the dcache shouldn't + * be required. + */ + else /* 68030 or 68020 */ + asm volatile ("movec %/cacr,%/d0\n\t" + "oriw %0,%/d0\n\t" + "movec %/d0,%/cacr" + : : "i" (FLUSH_I) + : "d0"); +#ifdef CONFIG_M68K_L2_CACHE + if(mach_l2_flush) + mach_l2_flush(1); +#endif +} +EXPORT_SYMBOL(cache_push); + |