xref: /openbmc/linux/arch/sh/mm/tlb-sh4.c (revision 1da177e4)
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  Paul Mundt
8  *
9  * Released under the terms of the GNU GPL v2.0.
10  */
11 #include <linux/signal.h>
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/string.h>
16 #include <linux/types.h>
17 #include <linux/ptrace.h>
18 #include <linux/mman.h>
19 #include <linux/mm.h>
20 #include <linux/smp.h>
21 #include <linux/smp_lock.h>
22 #include <linux/interrupt.h>
23 
24 #include <asm/system.h>
25 #include <asm/io.h>
26 #include <asm/uaccess.h>
27 #include <asm/pgalloc.h>
28 #include <asm/mmu_context.h>
29 #include <asm/cacheflush.h>
30 
31 void update_mmu_cache(struct vm_area_struct * vma,
32 		      unsigned long address, pte_t pte)
33 {
34 	unsigned long flags;
35 	unsigned long pteval;
36 	unsigned long vpn;
37 	struct page *page;
38 	unsigned long pfn;
39 	unsigned long ptea;
40 
41 	/* Ptrace may call this routine. */
42 	if (vma && current->active_mm != vma->vm_mm)
43 		return;
44 
45 	pfn = pte_pfn(pte);
46 	if (pfn_valid(pfn)) {
47 		page = pfn_to_page(pfn);
48 		if (!test_bit(PG_mapped, &page->flags)) {
49 			unsigned long phys = pte_val(pte) & PTE_PHYS_MASK;
50 			__flush_wback_region((void *)P1SEGADDR(phys), PAGE_SIZE);
51 			__set_bit(PG_mapped, &page->flags);
52 		}
53 	}
54 
55 	local_irq_save(flags);
56 
57 	/* Set PTEH register */
58 	vpn = (address & MMU_VPN_MASK) | get_asid();
59 	ctrl_outl(vpn, MMU_PTEH);
60 
61 	pteval = pte_val(pte);
62 	/* Set PTEA register */
63 	/* TODO: make this look less hacky */
64 	ptea = ((pteval >> 28) & 0xe) | (pteval & 0x1);
65 	ctrl_outl(ptea, MMU_PTEA);
66 
67 	/* Set PTEL register */
68 	pteval &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */
69 #ifdef CONFIG_SH_WRITETHROUGH
70 	pteval |= _PAGE_WT;
71 #endif
72 	/* conveniently, we want all the software flags to be 0 anyway */
73 	ctrl_outl(pteval, MMU_PTEL);
74 
75 	/* Load the TLB */
76 	asm volatile("ldtlb": /* no output */ : /* no input */ : "memory");
77 	local_irq_restore(flags);
78 }
79 
80 void __flush_tlb_page(unsigned long asid, unsigned long page)
81 {
82 	unsigned long addr, data;
83 
84 	/*
85 	 * NOTE: PTEH.ASID should be set to this MM
86 	 *       _AND_ we need to write ASID to the array.
87 	 *
88 	 * It would be simple if we didn't need to set PTEH.ASID...
89 	 */
90 	addr = MMU_UTLB_ADDRESS_ARRAY | MMU_PAGE_ASSOC_BIT;
91 	data = page | asid; /* VALID bit is off */
92 	jump_to_P2();
93 	ctrl_outl(data, addr);
94 	back_to_P1();
95 }
96 
97