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?  On tile64 this means we
 37 * mark the PTE to cache locally; on tilepro it means we have "nc" set.
 38 */
 39#define PAGE_HOME_IMMUTABLE -2
 40
 41/*
 42 * Each cpu considers its own cache to be the home for the page,
 43 * which makes it incoherent.
 44 */
 45#define PAGE_HOME_INCOHERENT -3
 46
 47#if CHIP_HAS_CBOX_HOME_MAP()
 48/* Home for the page is distributed via hash-for-home. */
 49#define PAGE_HOME_HASH -4
 50#endif
 51
 52/* Homing is unknown or unspecified.  Not valid for page_home(). */
 53#define PAGE_HOME_UNKNOWN -5
 54
 55/* Home on the current cpu.  Not valid for page_home(). */
 56#define PAGE_HOME_HERE -6
 57
 58/* Support wrapper to use instead of explicit hv_flush_remote(). */
 59extern void flush_remote(unsigned long cache_pfn, unsigned long cache_length,
 60			 const struct cpumask *cache_cpumask,
 61			 HV_VirtAddr tlb_va, unsigned long tlb_length,
 62			 unsigned long tlb_pgsize,
 63			 const struct cpumask *tlb_cpumask,
 64			 HV_Remote_ASID *asids, int asidcount);
 65
 66/* Set homing-related bits in a PTE (can also pass a pgprot_t). */
 67extern pte_t pte_set_home(pte_t pte, int home);
 68
 69/* Do a cache eviction on the specified cpus. */
 70extern void homecache_evict(const struct cpumask *mask);
 71
 72/*
 73 * Change a kernel page's homecache.  It must not be mapped in user space.
 74 * If !CONFIG_HOMECACHE, only usable on LOWMEM, and can only be called when
 75 * no other cpu can reference the page, and causes a full-chip cache/TLB flush.
 76 */
 77extern void homecache_change_page_home(struct page *, int order, int home);
 78
 79/*
 80 * Flush a page out of whatever cache(s) it is in.
 81 * This is more than just finv, since it properly handles waiting
 82 * for the data to reach memory on tilepro, but it can be quite
 83 * heavyweight, particularly on hash-for-home memory.
 84 */
 85extern void homecache_flush_cache(struct page *, int order);
 86
 87/*
 88 * Allocate a page with the given GFP flags, home, and optionally
 89 * node.  These routines are actually just wrappers around the normal
 90 * alloc_pages() / alloc_pages_node() functions, which set and clear
 91 * a per-cpu variable to communicate with homecache_new_kernel_page().
 92 * If !CONFIG_HOMECACHE, uses homecache_change_page_home().
 93 */
 94extern struct page *homecache_alloc_pages(gfp_t gfp_mask,
 95					  unsigned int order, int home);
 96extern struct page *homecache_alloc_pages_node(int nid, gfp_t gfp_mask,
 97					       unsigned int order, int home);
 98#define homecache_alloc_page(gfp_mask, home) \
 99  homecache_alloc_pages(gfp_mask, 0, home)
100
101/*
102 * These routines are just pass-throughs to free_pages() when
103 * we support full homecaching.  If !CONFIG_HOMECACHE, then these
104 * routines use homecache_change_page_home() to reset the home
105 * back to the default before returning the page to the allocator.
106 */
107void homecache_free_pages(unsigned long addr, unsigned int order);
108#define homecache_free_page(page) \
109  homecache_free_pages((page), 0)
110
111
112
113/*
114 * Report the page home for LOWMEM pages by examining their kernel PTE,
115 * or for highmem pages as the default home.
116 */
117extern int page_home(struct page *);
118
119#define homecache_migrate_kthread() do {} while (0)
120
121#define homecache_kpte_lock() 0
122#define homecache_kpte_unlock(flags) do {} while (0)
123
124
125#endif /* _ASM_TILE_HOMECACHE_H */