1 /* 2 * Copyright 2010 Tilera Corporation. All Rights Reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation, version 2. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or 11 * NON INFRINGEMENT. See the GNU General Public License for 12 * more details. 13 * 14 * Handle issues around the Tile "home cache" model of coherence. 15 */ 16 17 #ifndef _ASM_TILE_HOMECACHE_H 18 #define _ASM_TILE_HOMECACHE_H 19 20 #include <asm/page.h> 21 #include <linux/cpumask.h> 22 23 struct page; 24 struct task_struct; 25 struct vm_area_struct; 26 struct zone; 27 28 /* 29 * Coherence point for the page is its memory controller. 30 * It is not present in any cache (L1 or L2). 31 */ 32 #define PAGE_HOME_UNCACHED -1 33 34 /* 35 * Is this page immutable (unwritable) and thus able to be cached more 36 * widely than would otherwise be possible? This means we have "nc" set. 37 */ 38 #define PAGE_HOME_IMMUTABLE -2 39 40 /* 41 * Each cpu considers its own cache to be the home for the page, 42 * which makes it incoherent. 43 */ 44 #define PAGE_HOME_INCOHERENT -3 45 46 /* Home for the page is distributed via hash-for-home. */ 47 #define PAGE_HOME_HASH -4 48 49 /* Support wrapper to use instead of explicit hv_flush_remote(). */ 50 extern void flush_remote(unsigned long cache_pfn, unsigned long cache_length, 51 const struct cpumask *cache_cpumask, 52 HV_VirtAddr tlb_va, unsigned long tlb_length, 53 unsigned long tlb_pgsize, 54 const struct cpumask *tlb_cpumask, 55 HV_Remote_ASID *asids, int asidcount); 56 57 /* Set homing-related bits in a PTE (can also pass a pgprot_t). */ 58 extern pte_t pte_set_home(pte_t pte, int home); 59 60 /* Do a cache eviction on the specified cpus. */ 61 extern void homecache_evict(const struct cpumask *mask); 62 63 /* 64 * Change a kernel page's homecache. It must not be mapped in user space. 65 * If !CONFIG_HOMECACHE, only usable on LOWMEM, and can only be called when 66 * no other cpu can reference the page, and causes a full-chip cache/TLB flush. 67 */ 68 extern void homecache_change_page_home(struct page *, int order, int home); 69 70 /* 71 * Flush a page out of whatever cache(s) it is in. 72 * This is more than just finv, since it properly handles waiting 73 * for the data to reach memory, but it can be quite 74 * heavyweight, particularly on incoherent or immutable memory. 75 */ 76 extern void homecache_finv_page(struct page *); 77 78 /* 79 * Flush a page out of the specified home cache. 80 * Note that the specified home need not be the actual home of the page, 81 * as for example might be the case when coordinating with I/O devices. 82 */ 83 extern void homecache_finv_map_page(struct page *, int home); 84 85 /* 86 * Allocate a page with the given GFP flags, home, and optionally 87 * node. These routines are actually just wrappers around the normal 88 * alloc_pages() / alloc_pages_node() functions, which set and clear 89 * a per-cpu variable to communicate with homecache_new_kernel_page(). 90 * If !CONFIG_HOMECACHE, uses homecache_change_page_home(). 91 */ 92 extern struct page *homecache_alloc_pages(gfp_t gfp_mask, 93 unsigned int order, int home); 94 extern struct page *homecache_alloc_pages_node(int nid, gfp_t gfp_mask, 95 unsigned int order, int home); 96 #define homecache_alloc_page(gfp_mask, home) \ 97 homecache_alloc_pages(gfp_mask, 0, home) 98 99 /* 100 * These routines are just pass-throughs to free_pages() when 101 * we support full homecaching. If !CONFIG_HOMECACHE, then these 102 * routines use homecache_change_page_home() to reset the home 103 * back to the default before returning the page to the allocator. 104 */ 105 void __homecache_free_pages(struct page *, unsigned int order); 106 void homecache_free_pages(unsigned long addr, unsigned int order); 107 #define __homecache_free_page(page) __homecache_free_pages((page), 0) 108 #define homecache_free_page(page) homecache_free_pages((page), 0) 109 110 111 /* 112 * Report the page home for LOWMEM pages by examining their kernel PTE, 113 * or for highmem pages as the default home. 114 */ 115 extern int page_home(struct page *); 116 117 #define homecache_migrate_kthread() do {} while (0) 118 119 #define homecache_kpte_lock() 0 120 #define homecache_kpte_unlock(flags) do {} while (0) 121 122 123 #endif /* _ASM_TILE_HOMECACHE_H */ 124