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
 41/* Pass as vma pointer for non-executable mapping, if no vma available. */
 42#define FLUSH_NONEXEC ((struct vm_area_struct *)-1UL)
 43
 44/* Flush a single user page on this cpu. */
 45static inline void local_flush_tlb_page(struct vm_area_struct *vma,
 46					unsigned long addr,
 47					unsigned long page_size)
 48{
 49	int rc = hv_flush_page(addr, page_size);
 50	if (rc < 0)
 51		panic("hv_flush_page(%#lx,%#lx) failed: %d",
 52		      addr, page_size, rc);
 53	if (!vma || (vma != FLUSH_NONEXEC && (vma->vm_flags & VM_EXEC)))
 54		__flush_icache();
 55}
 56
 57/* Flush range of user pages on this cpu. */
 58static inline void local_flush_tlb_pages(struct vm_area_struct *vma,
 59					 unsigned long addr,
 60					 unsigned long page_size,
 61					 unsigned long len)
 62{
 63	int rc = hv_flush_pages(addr, page_size, len);
 64	if (rc < 0)
 65		panic("hv_flush_pages(%#lx,%#lx,%#lx) failed: %d",
 66		      addr, page_size, len, rc);
 67	if (!vma || (vma != FLUSH_NONEXEC && (vma->vm_flags & VM_EXEC)))
 68		__flush_icache();
 69}
 70
 71/* Flush all user pages on this cpu. */
 72static inline void local_flush_tlb(void)
 73{
 74	int rc = hv_flush_all(1);   /* preserve global mappings */
 75	if (rc < 0)
 76		panic("hv_flush_all(1) failed: %d", rc);
 77	__flush_icache();
 78}
 79
 80/*
 81 * Global pages have to be flushed a bit differently. Not a real
 82 * performance problem because this does not happen often.
 83 */
 84static inline void local_flush_tlb_all(void)
 85{
 86	int i;
 87	for (i = 0; ; ++i) {
 88		HV_VirtAddrRange r = hv_inquire_virtual(i);
 89		if (r.size == 0)
 90			break;
 91		local_flush_tlb_pages(NULL, r.start, PAGE_SIZE, r.size);
 92		local_flush_tlb_pages(NULL, r.start, HPAGE_SIZE, r.size);
 93	}
 94}
 95
 96/*
 97 * TLB flushing:
 98 *
 99 *  - flush_tlb() flushes the current mm struct TLBs
100 *  - flush_tlb_all() flushes all processes TLBs
101 *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
102 *  - flush_tlb_page(vma, vmaddr) flushes one page
103 *  - flush_tlb_range(vma, start, end) flushes a range of pages
104 *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
105 *  - flush_tlb_others(cpumask, mm, va) flushes TLBs on other cpus
106 *
107 * Here (as in vm_area_struct), "end" means the first byte after
108 * our end address.
109 */
110
111extern void flush_tlb_all(void);
112extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
113extern void flush_tlb_current_task(void);
114extern void flush_tlb_mm(struct mm_struct *);
115extern void flush_tlb_page(struct vm_area_struct *, unsigned long);
116extern void flush_tlb_page_mm(struct vm_area_struct *,
117			      struct mm_struct *, unsigned long);
118extern void flush_tlb_range(struct vm_area_struct *,
119			    unsigned long start, unsigned long end);
120
121#define flush_tlb()     flush_tlb_current_task()
122
123#endif /* _ASM_TILE_TLBFLUSH_H */