xref: /openbmc/linux/arch/sh/mm/tlb-sh4.c (revision 643d1f7f)
1 /*
2  * arch/sh/mm/tlb-sh4.c
3  *
4  * SH-4 specific TLB operations
5  *
6  * Copyright (C) 1999  Niibe Yutaka
7  * Copyright (C) 2002 - 2007 Paul Mundt
8  *
9  * Released under the terms of the GNU GPL v2.0.
10  */
11 #include <linux/kernel.h>
12 #include <linux/mm.h>
13 #include <linux/io.h>
14 #include <asm/system.h>
15 #include <asm/mmu_context.h>
16 #include <asm/cacheflush.h>
17 
18 void update_mmu_cache(struct vm_area_struct * vma,
19 		      unsigned long address, pte_t pte)
20 {
21 	unsigned long flags;
22 	unsigned long pteval;
23 	unsigned long vpn;
24 
25 	/* Ptrace may call this routine. */
26 	if (vma && current->active_mm != vma->vm_mm)
27 		return;
28 
29 #ifndef CONFIG_CACHE_OFF
30 	{
31 		unsigned long pfn = pte_pfn(pte);
32 
33 		if (pfn_valid(pfn)) {
34 			struct page *page = pfn_to_page(pfn);
35 
36 			if (!test_bit(PG_mapped, &page->flags)) {
37 				unsigned long phys = pte_val(pte) & PTE_PHYS_MASK;
38 				__flush_wback_region((void *)P1SEGADDR(phys),
39 						     PAGE_SIZE);
40 				__set_bit(PG_mapped, &page->flags);
41 			}
42 		}
43 	}
44 #endif
45 
46 	local_irq_save(flags);
47 
48 	/* Set PTEH register */
49 	vpn = (address & MMU_VPN_MASK) | get_asid();
50 	ctrl_outl(vpn, MMU_PTEH);
51 
52 	pteval = pte.pte_low;
53 
54 	/* Set PTEA register */
55 #ifdef CONFIG_X2TLB
56 	/*
57 	 * For the extended mode TLB this is trivial, only the ESZ and
58 	 * EPR bits need to be written out to PTEA, with the remainder of
59 	 * the protection bits (with the exception of the compat-mode SZ
60 	 * and PR bits, which are cleared) being written out in PTEL.
61 	 */
62 	ctrl_outl(pte.pte_high, MMU_PTEA);
63 #else
64 	if (cpu_data->flags & CPU_HAS_PTEA)
65 		/* TODO: make this look less hacky */
66 		ctrl_outl(((pteval >> 28) & 0xe) | (pteval & 0x1), 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 	ctrl_outl(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 void __uses_jump_to_uncached local_flush_tlb_one(unsigned long asid,
83 						 unsigned long page)
84 {
85 	unsigned long addr, data;
86 
87 	/*
88 	 * NOTE: PTEH.ASID should be set to this MM
89 	 *       _AND_ we need to write ASID to the array.
90 	 *
91 	 * It would be simple if we didn't need to set PTEH.ASID...
92 	 */
93 	addr = MMU_UTLB_ADDRESS_ARRAY | MMU_PAGE_ASSOC_BIT;
94 	data = page | asid; /* VALID bit is off */
95 	jump_to_uncached();
96 	ctrl_outl(data, addr);
97 	back_to_cached();
98 }
99