/* * 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/system.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; #ifdef DEBUG printk("init_pointer_table: %lx, %x\n", ptable, PD_MARKBITS(dp)); #endif /* 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_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_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);