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
23struct page;
24struct task_struct;
25struct vm_area_struct;
26struct 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(). */
50extern 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). */
58extern pte_t pte_set_home(pte_t pte, int home);
59
60/* Do a cache eviction on the specified cpus. */
61extern 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 */
68extern 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 */
76extern 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 */
83extern 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 */
92extern struct page *homecache_alloc_pages(gfp_t gfp_mask,
93					  unsigned int order, int home);
94extern 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 */
105void __homecache_free_pages(struct page *, unsigned int order);
106void 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 */
115extern 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