xref: /openbmc/linux/arch/ia64/include/asm/tlb.h (revision a72afd87)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_IA64_TLB_H
3 #define _ASM_IA64_TLB_H
4 /*
5  * Based on <asm-generic/tlb.h>.
6  *
7  * Copyright (C) 2002-2003 Hewlett-Packard Co
8  *	David Mosberger-Tang <davidm@hpl.hp.com>
9  */
10 /*
11  * Removing a translation from a page table (including TLB-shootdown) is a four-step
12  * procedure:
13  *
14  *	(1) Flush (virtual) caches --- ensures virtual memory is coherent with kernel memory
15  *	    (this is a no-op on ia64).
16  *	(2) Clear the relevant portions of the page-table
17  *	(3) Flush the TLBs --- ensures that stale content is gone from CPU TLBs
18  *	(4) Release the pages that were freed up in step (2).
19  *
20  * Note that the ordering of these steps is crucial to avoid races on MP machines.
21  *
22  * The Linux kernel defines several platform-specific hooks for TLB-shootdown.  When
23  * unmapping a portion of the virtual address space, these hooks are called according to
24  * the following template:
25  *
26  *	tlb <- tlb_gather_mmu(mm);			// start unmap for address space MM
27  *	{
28  *	  for each vma that needs a shootdown do {
29  *	    tlb_start_vma(tlb, vma);
30  *	      for each page-table-entry PTE that needs to be removed do {
31  *		tlb_remove_tlb_entry(tlb, pte, address);
32  *		if (pte refers to a normal page) {
33  *		  tlb_remove_page(tlb, page);
34  *		}
35  *	      }
36  *	    tlb_end_vma(tlb, vma);
37  *	  }
38  *	}
39  *	tlb_finish_mmu(tlb);				// finish unmap for address space MM
40  */
41 #include <linux/mm.h>
42 #include <linux/pagemap.h>
43 #include <linux/swap.h>
44 
45 #include <asm/processor.h>
46 #include <asm/tlbflush.h>
47 
48 #include <asm-generic/tlb.h>
49 
50 #endif /* _ASM_IA64_TLB_H */
51