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
 15#ifndef _ASM_TILE_TLBFLUSH_H
 16#define _ASM_TILE_TLBFLUSH_H
 17
 18#include <linux/mm.h>
 19#include <linux/sched.h>
 20#include <linux/smp.h>
 21#include <asm/cacheflush.h>
 22#include <asm/page.h>
 23#include <hv/hypervisor.h>
 24
 25/*
 26 * Rather than associating each mm with its own ASID, we just use
 27 * ASIDs to allow us to lazily flush the TLB when we switch mms.
 28 * This way we only have to do an actual TLB flush on mm switch
 29 * every time we wrap ASIDs, not every single time we switch.
 30 *
 31 * FIXME: We might improve performance by keeping ASIDs around
 32 * properly, though since the hypervisor direct-maps VAs to TSB
 33 * entries, we're likely to have lost at least the executable page
 34 * mappings by the time we switch back to the original mm.
 35 */
 36DECLARE_PER_CPU(int, current_asid);
 37
 38/* The hypervisor tells us what ASIDs are available to us. */
 39extern int min_asid, max_asid;
 40
 41static inline unsigned long hv_page_size(const struct vm_area_struct *vma)
 42{
 43	return (vma->vm_flags & VM_HUGETLB) ? HPAGE_SIZE : PAGE_SIZE;
 44}
 45
 46/* Pass as vma pointer for non-executable mapping, if no vma available. */
 47#define FLUSH_NONEXEC ((const struct vm_area_struct *)-1UL)
 48
 49/* Flush a single user page on this cpu. */
 50static inline void local_flush_tlb_page(const struct vm_area_struct *vma,
 51					unsigned long addr,
 52					unsigned long page_size)
 53{
 54	int rc = hv_flush_page(addr, page_size);
 55	if (rc < 0)
 56		panic("hv_flush_page(%#lx,%#lx) failed: %d",
 57		      addr, page_size, rc);
 58	if (!vma || (vma != FLUSH_NONEXEC && (vma->vm_flags & VM_EXEC)))
 59		__flush_icache();
 60}
 61
 62/* Flush range of user pages on this cpu. */
 63static inline void local_flush_tlb_pages(const struct vm_area_struct *vma,
 64					 unsigned long addr,
 65					 unsigned long page_size,
 66					 unsigned long len)
 67{
 68	int rc = hv_flush_pages(addr, page_size, len);
 69	if (rc < 0)
 70		panic("hv_flush_pages(%#lx,%#lx,%#lx) failed: %d",
 71		      addr, page_size, len, rc);
 72	if (!vma || (vma != FLUSH_NONEXEC && (vma->vm_flags & VM_EXEC)))
 73		__flush_icache();
 74}
 75
 76/* Flush all user pages on this cpu. */
 77static inline void local_flush_tlb(void)
 78{
 79	int rc = hv_flush_all(1);   /* preserve global mappings */
 80	if (rc < 0)
 81		panic("hv_flush_all(1) failed: %d", rc);
 82	__flush_icache();
 83}
 84
 85/*
 86 * Global pages have to be flushed a bit differently. Not a real
 87 * performance problem because this does not happen often.
 88 */
 89static inline void local_flush_tlb_all(void)
 90{
 91	int i;
 92	for (i = 0; ; ++i) {
 93		HV_VirtAddrRange r = hv_inquire_virtual(i);
 94		if (r.size == 0)
 95			break;
 96		local_flush_tlb_pages(NULL, r.start, PAGE_SIZE, r.size);
 97		local_flush_tlb_pages(NULL, r.start, HPAGE_SIZE, r.size);
 98	}
 99}
100
101/*
102 * TLB flushing:
103 *
104 *  - flush_tlb() flushes the current mm struct TLBs
105 *  - flush_tlb_all() flushes all processes TLBs
106 *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
107 *  - flush_tlb_page(vma, vmaddr) flushes one page
108 *  - flush_tlb_range(vma, start, end) flushes a range of pages
109 *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
110 *  - flush_tlb_others(cpumask, mm, va) flushes TLBs on other cpus
111 *
112 * Here (as in vm_area_struct), "end" means the first byte after
113 * our end address.
114 */
115
116extern void flush_tlb_all(void);
117extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
118extern void flush_tlb_current_task(void);
119extern void flush_tlb_mm(struct mm_struct *);
120extern void flush_tlb_page(const struct vm_area_struct *, unsigned long);
121extern void flush_tlb_page_mm(const struct vm_area_struct *,
122			      struct mm_struct *, unsigned long);
123extern void flush_tlb_range(const struct vm_area_struct *,
124			    unsigned long start, unsigned long end);
125
126#define flush_tlb()     flush_tlb_current_task()
127
128#endif /* _ASM_TILE_TLBFLUSH_H */