xref: /openbmc/linux/arch/sh/mm/tlb-pteaex.c (revision b627b4ed)
1 /*
2  * arch/sh/mm/tlb-pteaex.c
3  *
4  * TLB operations for SH-X3 CPUs featuring PTE ASID Extensions.
5  *
6  * Copyright (C) 2009 Paul Mundt
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file "COPYING" in the main directory of this archive
10  * for more details.
11  */
12 #include <linux/kernel.h>
13 #include <linux/mm.h>
14 #include <linux/io.h>
15 #include <asm/system.h>
16 #include <asm/mmu_context.h>
17 #include <asm/cacheflush.h>
18 
19 void update_mmu_cache(struct vm_area_struct * vma,
20 		      unsigned long address, pte_t pte)
21 {
22 	unsigned long flags;
23 	unsigned long pteval;
24 	unsigned long vpn;
25 
26 	/* Ptrace may call this routine. */
27 	if (vma && current->active_mm != vma->vm_mm)
28 		return;
29 
30 #ifndef CONFIG_CACHE_OFF
31 	{
32 		unsigned long pfn = pte_pfn(pte);
33 
34 		if (pfn_valid(pfn)) {
35 			struct page *page = pfn_to_page(pfn);
36 
37 			if (!test_bit(PG_mapped, &page->flags)) {
38 				unsigned long phys = pte_val(pte) & PTE_PHYS_MASK;
39 				__flush_wback_region((void *)P1SEGADDR(phys),
40 						     PAGE_SIZE);
41 				__set_bit(PG_mapped, &page->flags);
42 			}
43 		}
44 	}
45 #endif
46 
47 	local_irq_save(flags);
48 
49 	/* Set PTEH register */
50 	vpn = address & MMU_VPN_MASK;
51 	__raw_writel(vpn, MMU_PTEH);
52 
53 	/* Set PTEAEX */
54 	__raw_writel(get_asid(), MMU_PTEAEX);
55 
56 	pteval = pte.pte_low;
57 
58 	/* Set PTEA register */
59 #ifdef CONFIG_X2TLB
60 	/*
61 	 * For the extended mode TLB this is trivial, only the ESZ and
62 	 * EPR bits need to be written out to PTEA, with the remainder of
63 	 * the protection bits (with the exception of the compat-mode SZ
64 	 * and PR bits, which are cleared) being written out in PTEL.
65 	 */
66 	__raw_writel(pte.pte_high, MMU_PTEA);
67 #endif
68 
69 	/* Set PTEL register */
70 	pteval &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */
71 #ifdef CONFIG_CACHE_WRITETHROUGH
72 	pteval |= _PAGE_WT;
73 #endif
74 	/* conveniently, we want all the software flags to be 0 anyway */
75 	__raw_writel(pteval, MMU_PTEL);
76 
77 	/* Load the TLB */
78 	asm volatile("ldtlb": /* no output */ : /* no input */ : "memory");
79 	local_irq_restore(flags);
80 }
81 
82 /*
83  * While SH-X2 extended TLB mode splits out the memory-mapped I/UTLB
84  * data arrays, SH-X3 cores with PTEAEX split out the memory-mapped
85  * address arrays. In compat mode the second array is inaccessible, while
86  * in extended mode, the legacy 8-bit ASID field in address array 1 has
87  * undefined behaviour.
88  */
89 void __uses_jump_to_uncached local_flush_tlb_one(unsigned long asid,
90 						 unsigned long page)
91 {
92 	jump_to_uncached();
93 	__raw_writel(page, MMU_UTLB_ADDRESS_ARRAY | MMU_PAGE_ASSOC_BIT);
94 	__raw_writel(asid, MMU_UTLB_ADDRESS_ARRAY2 | MMU_PAGE_ASSOC_BIT);
95 	back_to_cached();
96 }
97